Commit Graph

655 Commits

Author SHA1 Message Date
Marc Zyngier
19f3e7ea29 KVM: arm64: Register AArch64 system register entries with the sysreg xarray
In order to reduce the number of lookups that we have to perform
when handling a sysreg, register each AArch64 sysreg descriptor
with the global xarray. The index of the descriptor is stored
as a 10 bit field in the data word.

Subsequent patches will retrieve and use the stored index.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-15-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:01 +00:00
Marc Zyngier
888f088070 KVM: arm64: nv: Add sanitising to VNCR-backed sysregs
VNCR-backed "registers" are actually only memory. Which means that
there is zero control over what the guest can write, and that it
is the hypervisor's job to actually sanitise the content of the
backing store. Yeah, this is fun.

In order to preserve some form of sanity, add a repainting mechanism
that makes use of a per-VM set of RES0/RES1 masks, one pair per VNCR
register. These masks get applied on access to the backing store via
__vcpu_sys_reg(), ensuring that the state that is consumed by KVM is
correct.

So far, nothing populates these masks, but stay tuned.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20240214131827.2856277-4-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
c62d7a23b9 KVM: arm64: Add feature checking helpers
In order to make it easier to check whether a particular feature
is exposed to a guest, add a new set of helpers, with kvm_has_feat()
being the most useful.

Let's start making use of them in the PMU code (courtesy of Oliver).
Follow-up changes will introduce additional use patterns.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Co-developed--by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-3-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:12:59 +00:00
Paolo Bonzini
5f53d88f10 KVM/arm64 updates for Linux 6.8
- LPA2 support, adding 52bit IPA/PA capability for 4kB and 16kB
   base granule sizes. Branch shared with the arm64 tree.
 
 - Large Fine-Grained Trap rework, bringing some sanity to the
   feature, although there is more to come. This comes with
   a prefix branch shared with the arm64 tree.
 
 - Some additional Nested Virtualization groundwork, mostly
   introducing the NV2 VNCR support and retargetting the NV
   support to that version of the architecture.
 
 - A small set of vgic fixes and associated cleanups.
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Merge tag 'kvmarm-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for Linux 6.8

- LPA2 support, adding 52bit IPA/PA capability for 4kB and 16kB
  base granule sizes. Branch shared with the arm64 tree.

- Large Fine-Grained Trap rework, bringing some sanity to the
  feature, although there is more to come. This comes with
  a prefix branch shared with the arm64 tree.

- Some additional Nested Virtualization groundwork, mostly
  introducing the NV2 VNCR support and retargetting the NV
  support to that version of the architecture.

- A small set of vgic fixes and associated cleanups.
2024-01-08 08:09:53 -05:00
Marc Zyngier
d016264d07 Merge branch kvm-arm64/nv-6.8-prefix into kvmarm-master/next
* kvm-arm64/nv-6.8-prefix:
  : .
  : Nested Virtualization support update, focussing on the
  : NV2 support (VNCR mapping and such).
  : .
  KVM: arm64: nv: Handle virtual EL2 registers in vcpu_read/write_sys_reg()
  KVM: arm64: nv: Map VNCR-capable registers to a separate page
  KVM: arm64: nv: Add EL2_REG_VNCR()/EL2_REG_REDIR() sysreg helpers
  KVM: arm64: Introduce a bad_trap() primitive for unexpected trap handling
  KVM: arm64: nv: Add include containing the VNCR_EL2 offsets
  KVM: arm64: nv: Add non-VHE-EL2->EL1 translation helpers
  KVM: arm64: nv: Drop EL12 register traps that are redirected to VNCR
  KVM: arm64: nv: Compute NV view of idregs as a one-off
  KVM: arm64: nv: Hoist vcpu_has_nv() into is_hyp_ctxt()
  arm64: cpufeatures: Restrict NV support to FEAT_NV2

Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-12-19 10:06:58 +00:00
Marc Zyngier
fedc612314 KVM: arm64: nv: Handle virtual EL2 registers in vcpu_read/write_sys_reg()
KVM internally uses accessor functions when reading or writing the
guest's system registers. This takes care of accessing either the stored
copy or using the "live" EL1 system registers when the host uses VHE.

With the introduction of virtual EL2 we add a bunch of EL2 system
registers, which now must also be taken care of:

- If the guest is running in vEL2, and we access an EL1 sysreg, we must
  revert to the stored version of that, and not use the CPU's copy.

- If the guest is running in vEL1, and we access an EL2 sysreg, we must
  also use the stored version, since the CPU carries the EL1 copy.

- Some EL2 system registers are supposed to affect the current execution
  of the system, so we need to put them into their respective EL1
  counterparts. For this we need to define a mapping between the two.

- Some EL2 system registers have a different format than their EL1
  counterpart, so we need to translate them before writing them to the
  CPU. This is done using an (optional) translate function in the map.

All of these cases are now wrapped into the existing accessor functions,
so KVM users wouldn't need to care whether they access EL2 or EL1
registers and also which state the guest is in.

Reviewed-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Co-developed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-12-19 10:02:53 +00:00
Marc Zyngier
d8bd48e3f0 KVM: arm64: nv: Map VNCR-capable registers to a separate page
With ARMv8.4-NV, registers that can be directly accessed in memory
by the guest have to live at architected offsets in a special page.

Let's annotate the sysreg enum to reflect the offset at which they
are in this page, whith a little twist:

If running on HW that doesn't have the ARMv8.4-NV feature, or even
a VM that doesn't use NV, we store all the system registers in the
usual sys_regs array. The only difference with the pre-8.4
situation is that VNCR-capable registers are at a "similar" offset
as in the VNCR page (we can compute the actual offset at compile
time), and that the sys_regs array is both bigger and sparse.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-12-19 10:02:42 +00:00
Marc Zyngier
3ed0b5123c KVM: arm64: nv: Compute NV view of idregs as a one-off
Now that we have a full copy of the idregs for each VM, there is
no point in repainting the sysregs on each access. Instead, we
can simply perform the transmation as a one-off and be done
with it.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-12-19 09:51:00 +00:00
Marc Zyngier
111903d1f5 KVM: arm64: nv: Hoist vcpu_has_nv() into is_hyp_ctxt()
A rather common idiom when writing NV code as part of KVM is
to have things such has:

	if (vcpu_has_nv(vcpu) && is_hyp_ctxt(vcpu)) {
		[...]
	}

to check that we are in a hyp-related context. The second part of
the conjunction would be enough, but the first one contains a
static key that allows the rest of the checkis to be elided when
in a non-NV environment.

Rewrite is_hyp_ctxt() to directly use vcpu_has_nv(). The result
is the same, and the code easier to read. The one occurence of
this that is already merged is rewritten in the process.

In order to avoid nasty cirtular dependencies between kvm_emulate.h
and kvm_nested.h, vcpu_has_feature() is itself hoisted into kvm_host.h,
at the cost of some #deferry...

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-12-19 09:50:52 +00:00
Fuad Tabba
676f482354 KVM: arm64: Handle HAFGRTR_EL2 trapping in nested virt
Add the encodings to fine grain trapping fields for HAFGRTR_EL2
and add the associated handling code in nested virt. Based on
DDI0601 2023-09. Add the missing field definitions as well,
both to generate the correct RES0 mask and to be able to toggle
their FGT bits.

Also add the code for handling FGT trapping, reading of the
register, to nested virt.

Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231214100158.2305400-10-tabba@google.com
2023-12-18 11:25:50 +00:00
Paolo Bonzini
6c370dc653 Merge branch 'kvm-guestmemfd' into HEAD
Introduce several new KVM uAPIs to ultimately create a guest-first memory
subsystem within KVM, a.k.a. guest_memfd.  Guest-first memory allows KVM
to provide features, enhancements, and optimizations that are kludgly
or outright impossible to implement in a generic memory subsystem.

The core KVM ioctl() for guest_memfd is KVM_CREATE_GUEST_MEMFD, which
similar to the generic memfd_create(), creates an anonymous file and
returns a file descriptor that refers to it.  Again like "regular"
memfd files, guest_memfd files live in RAM, have volatile storage,
and are automatically released when the last reference is dropped.
The key differences between memfd files (and every other memory subystem)
is that guest_memfd files are bound to their owning virtual machine,
cannot be mapped, read, or written by userspace, and cannot be resized.
guest_memfd files do however support PUNCH_HOLE, which can be used to
convert a guest memory area between the shared and guest-private states.

A second KVM ioctl(), KVM_SET_MEMORY_ATTRIBUTES, allows userspace to
specify attributes for a given page of guest memory.  In the long term,
it will likely be extended to allow userspace to specify per-gfn RWX
protections, including allowing memory to be writable in the guest
without it also being writable in host userspace.

The immediate and driving use case for guest_memfd are Confidential
(CoCo) VMs, specifically AMD's SEV-SNP, Intel's TDX, and KVM's own pKVM.
For such use cases, being able to map memory into KVM guests without
requiring said memory to be mapped into the host is a hard requirement.
While SEV+ and TDX prevent untrusted software from reading guest private
data by encrypting guest memory, pKVM provides confidentiality and
integrity *without* relying on memory encryption.  In addition, with
SEV-SNP and especially TDX, accessing guest private memory can be fatal
to the host, i.e. KVM must be prevent host userspace from accessing
guest memory irrespective of hardware behavior.

Long term, guest_memfd may be useful for use cases beyond CoCo VMs,
for example hardening userspace against unintentional accesses to guest
memory.  As mentioned earlier, KVM's ABI uses userspace VMA protections to
define the allow guest protection (with an exception granted to mapping
guest memory executable), and similarly KVM currently requires the guest
mapping size to be a strict subset of the host userspace mapping size.
Decoupling the mappings sizes would allow userspace to precisely map
only what is needed and with the required permissions, without impacting
guest performance.

A guest-first memory subsystem also provides clearer line of sight to
things like a dedicated memory pool (for slice-of-hardware VMs) and
elimination of "struct page" (for offload setups where userspace _never_
needs to DMA from or into guest memory).

guest_memfd is the result of 3+ years of development and exploration;
taking on memory management responsibilities in KVM was not the first,
second, or even third choice for supporting CoCo VMs.  But after many
failed attempts to avoid KVM-specific backing memory, and looking at
where things ended up, it is quite clear that of all approaches tried,
guest_memfd is the simplest, most robust, and most extensible, and the
right thing to do for KVM and the kernel at-large.

The "development cycle" for this version is going to be very short;
ideally, next week I will merge it as is in kvm/next, taking this through
the KVM tree for 6.8 immediately after the end of the merge window.
The series is still based on 6.6 (plus KVM changes for 6.7) so it
will require a small fixup for changes to get_file_rcu() introduced in
6.7 by commit 0ede61d858 ("file: convert to SLAB_TYPESAFE_BY_RCU").
The fixup will be done as part of the merge commit, and most of the text
above will become the commit message for the merge.

Pending post-merge work includes:
- hugepage support
- looking into using the restrictedmem framework for guest memory
- introducing a testing mechanism to poison memory, possibly using
  the same memory attributes introduced here
- SNP and TDX support

There are two non-KVM patches buried in the middle of this series:

  fs: Rename anon_inode_getfile_secure() and anon_inode_getfd_secure()
  mm: Add AS_UNMOVABLE to mark mapping as completely unmovable

The first is small and mostly suggested-by Christian Brauner; the second
a bit less so but it was written by an mm person (Vlastimil Babka).
2023-11-14 08:31:31 -05:00
Sean Christopherson
f128cf8cfb KVM: Convert KVM_ARCH_WANT_MMU_NOTIFIER to CONFIG_KVM_GENERIC_MMU_NOTIFIER
Convert KVM_ARCH_WANT_MMU_NOTIFIER into a Kconfig and select it where
appropriate to effectively maintain existing behavior.  Using a proper
Kconfig will simplify building more functionality on top of KVM's
mmu_notifier infrastructure.

Add a forward declaration of kvm_gfn_range to kvm_types.h so that
including arch/powerpc/include/asm/kvm_ppc.h's with CONFIG_KVM=n doesn't
generate warnings due to kvm_gfn_range being undeclared.  PPC defines
hooks for PR vs. HV without guarding them via #ifdeffery, e.g.

  bool (*unmap_gfn_range)(struct kvm *kvm, struct kvm_gfn_range *range);
  bool (*age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
  bool (*test_age_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);
  bool (*set_spte_gfn)(struct kvm *kvm, struct kvm_gfn_range *range);

Alternatively, PPC could forward declare kvm_gfn_range, but there's no
good reason not to define it in common KVM.

Acked-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Message-Id: <20231027182217.3615211-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-11-13 05:29:09 -05:00
Linus Torvalds
6803bd7956 ARM:
* Generalized infrastructure for 'writable' ID registers, effectively
   allowing userspace to opt-out of certain vCPU features for its guest
 
 * Optimization for vSGI injection, opportunistically compressing MPIDR
   to vCPU mapping into a table
 
 * Improvements to KVM's PMU emulation, allowing userspace to select
   the number of PMCs available to a VM
 
 * Guest support for memory operation instructions (FEAT_MOPS)
 
 * Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing
   bugs and getting rid of useless code
 
 * Changes to the way the SMCCC filter is constructed, avoiding wasted
   memory allocations when not in use
 
 * Load the stage-2 MMU context at vcpu_load() for VHE systems, reducing
   the overhead of errata mitigations
 
 * Miscellaneous kernel and selftest fixes
 
 LoongArch:
 
 * New architecture.  The hardware uses the same model as x86, s390
   and RISC-V, where guest/host mode is orthogonal to supervisor/user
   mode.  The virtualization extensions are very similar to MIPS,
   therefore the code also has some similarities but it's been cleaned
   up to avoid some of the historical bogosities that are found in
   arch/mips.  The kernel emulates MMU, timer and CSR accesses, while
   interrupt controllers are only emulated in userspace, at least for
   now.
 
 RISC-V:
 
 * Support for the Smstateen and Zicond extensions
 
 * Support for virtualizing senvcfg
 
 * Support for virtualized SBI debug console (DBCN)
 
 S390:
 
 * Nested page table management can be monitored through tracepoints
   and statistics
 
 x86:
 
 * Fix incorrect handling of VMX posted interrupt descriptor in KVM_SET_LAPIC,
   which could result in a dropped timer IRQ
 
 * Avoid WARN on systems with Intel IPI virtualization
 
 * Add CONFIG_KVM_MAX_NR_VCPUS, to allow supporting up to 4096 vCPUs without
   forcing more common use cases to eat the extra memory overhead.
 
 * Add virtualization support for AMD SRSO mitigation (IBPB_BRTYPE and
   SBPB, aka Selective Branch Predictor Barrier).
 
 * Fix a bug where restoring a vCPU snapshot that was taken within 1 second of
   creating the original vCPU would cause KVM to try to synchronize the vCPU's
   TSC and thus clobber the correct TSC being set by userspace.
 
 * Compute guest wall clock using a single TSC read to avoid generating an
   inaccurate time, e.g. if the vCPU is preempted between multiple TSC reads.
 
 * "Virtualize" HWCR.TscFreqSel to make Linux guests happy, which complain
   about a "Firmware Bug" if the bit isn't set for select F/M/S combos.
   Likewise "virtualize" (ignore) MSR_AMD64_TW_CFG to appease Windows Server
   2022.
 
 * Don't apply side effects to Hyper-V's synthetic timer on writes from
   userspace to fix an issue where the auto-enable behavior can trigger
   spurious interrupts, i.e. do auto-enabling only for guest writes.
 
 * Remove an unnecessary kick of all vCPUs when synchronizing the dirty log
   without PML enabled.
 
 * Advertise "support" for non-serializing FS/GS base MSR writes as appropriate.
 
 * Harden the fast page fault path to guard against encountering an invalid
   root when walking SPTEs.
 
 * Omit "struct kvm_vcpu_xen" entirely when CONFIG_KVM_XEN=n.
 
 * Use the fast path directly from the timer callback when delivering Xen
   timer events, instead of waiting for the next iteration of the run loop.
   This was not done so far because previously proposed code had races,
   but now care is taken to stop the hrtimer at critical points such as
   restarting the timer or saving the timer information for userspace.
 
 * Follow the lead of upstream Xen and ignore the VCPU_SSHOTTMR_future flag.
 
 * Optimize injection of PMU interrupts that are simultaneous with NMIs.
 
 * Usual handful of fixes for typos and other warts.
 
 x86 - MTRR/PAT fixes and optimizations:
 
 * Clean up code that deals with honoring guest MTRRs when the VM has
   non-coherent DMA and host MTRRs are ignored, i.e. EPT is enabled.
 
 * Zap EPT entries when non-coherent DMA assignment stops/start to prevent
   using stale entries with the wrong memtype.
 
 * Don't ignore guest PAT for CR0.CD=1 && KVM_X86_QUIRK_CD_NW_CLEARED=y.
   This was done as a workaround for virtual machine BIOSes that did not
   bother to clear CR0.CD (because ancient KVM/QEMU did not bother to
   set it, in turn), and there's zero reason to extend the quirk to
   also ignore guest PAT.
 
 x86 - SEV fixes:
 
 * Report KVM_EXIT_SHUTDOWN instead of EINVAL if KVM intercepts SHUTDOWN while
   running an SEV-ES guest.
 
 * Clean up the recognition of emulation failures on SEV guests, when KVM would
   like to "skip" the instruction but it had already been partially emulated.
   This makes it possible to drop a hack that second guessed the (insufficient)
   information provided by the emulator, and just do the right thing.
 
 Documentation:
 
 * Various updates and fixes, mostly for x86
 
 * MTRR and PAT fixes and optimizations:
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:

   - Generalized infrastructure for 'writable' ID registers, effectively
     allowing userspace to opt-out of certain vCPU features for its
     guest

   - Optimization for vSGI injection, opportunistically compressing
     MPIDR to vCPU mapping into a table

   - Improvements to KVM's PMU emulation, allowing userspace to select
     the number of PMCs available to a VM

   - Guest support for memory operation instructions (FEAT_MOPS)

   - Cleanups to handling feature flags in KVM_ARM_VCPU_INIT, squashing
     bugs and getting rid of useless code

   - Changes to the way the SMCCC filter is constructed, avoiding wasted
     memory allocations when not in use

   - Load the stage-2 MMU context at vcpu_load() for VHE systems,
     reducing the overhead of errata mitigations

   - Miscellaneous kernel and selftest fixes

  LoongArch:

   - New architecture for kvm.

     The hardware uses the same model as x86, s390 and RISC-V, where
     guest/host mode is orthogonal to supervisor/user mode. The
     virtualization extensions are very similar to MIPS, therefore the
     code also has some similarities but it's been cleaned up to avoid
     some of the historical bogosities that are found in arch/mips. The
     kernel emulates MMU, timer and CSR accesses, while interrupt
     controllers are only emulated in userspace, at least for now.

  RISC-V:

   - Support for the Smstateen and Zicond extensions

   - Support for virtualizing senvcfg

   - Support for virtualized SBI debug console (DBCN)

  S390:

   - Nested page table management can be monitored through tracepoints
     and statistics

  x86:

   - Fix incorrect handling of VMX posted interrupt descriptor in
     KVM_SET_LAPIC, which could result in a dropped timer IRQ

   - Avoid WARN on systems with Intel IPI virtualization

   - Add CONFIG_KVM_MAX_NR_VCPUS, to allow supporting up to 4096 vCPUs
     without forcing more common use cases to eat the extra memory
     overhead.

   - Add virtualization support for AMD SRSO mitigation (IBPB_BRTYPE and
     SBPB, aka Selective Branch Predictor Barrier).

   - Fix a bug where restoring a vCPU snapshot that was taken within 1
     second of creating the original vCPU would cause KVM to try to
     synchronize the vCPU's TSC and thus clobber the correct TSC being
     set by userspace.

   - Compute guest wall clock using a single TSC read to avoid
     generating an inaccurate time, e.g. if the vCPU is preempted
     between multiple TSC reads.

   - "Virtualize" HWCR.TscFreqSel to make Linux guests happy, which
     complain about a "Firmware Bug" if the bit isn't set for select
     F/M/S combos. Likewise "virtualize" (ignore) MSR_AMD64_TW_CFG to
     appease Windows Server 2022.

   - Don't apply side effects to Hyper-V's synthetic timer on writes
     from userspace to fix an issue where the auto-enable behavior can
     trigger spurious interrupts, i.e. do auto-enabling only for guest
     writes.

   - Remove an unnecessary kick of all vCPUs when synchronizing the
     dirty log without PML enabled.

   - Advertise "support" for non-serializing FS/GS base MSR writes as
     appropriate.

   - Harden the fast page fault path to guard against encountering an
     invalid root when walking SPTEs.

   - Omit "struct kvm_vcpu_xen" entirely when CONFIG_KVM_XEN=n.

   - Use the fast path directly from the timer callback when delivering
     Xen timer events, instead of waiting for the next iteration of the
     run loop. This was not done so far because previously proposed code
     had races, but now care is taken to stop the hrtimer at critical
     points such as restarting the timer or saving the timer information
     for userspace.

   - Follow the lead of upstream Xen and ignore the VCPU_SSHOTTMR_future
     flag.

   - Optimize injection of PMU interrupts that are simultaneous with
     NMIs.

   - Usual handful of fixes for typos and other warts.

  x86 - MTRR/PAT fixes and optimizations:

   - Clean up code that deals with honoring guest MTRRs when the VM has
     non-coherent DMA and host MTRRs are ignored, i.e. EPT is enabled.

   - Zap EPT entries when non-coherent DMA assignment stops/start to
     prevent using stale entries with the wrong memtype.

   - Don't ignore guest PAT for CR0.CD=1 && KVM_X86_QUIRK_CD_NW_CLEARED=y

     This was done as a workaround for virtual machine BIOSes that did
     not bother to clear CR0.CD (because ancient KVM/QEMU did not bother
     to set it, in turn), and there's zero reason to extend the quirk to
     also ignore guest PAT.

  x86 - SEV fixes:

   - Report KVM_EXIT_SHUTDOWN instead of EINVAL if KVM intercepts
     SHUTDOWN while running an SEV-ES guest.

   - Clean up the recognition of emulation failures on SEV guests, when
     KVM would like to "skip" the instruction but it had already been
     partially emulated. This makes it possible to drop a hack that
     second guessed the (insufficient) information provided by the
     emulator, and just do the right thing.

  Documentation:

   - Various updates and fixes, mostly for x86

   - MTRR and PAT fixes and optimizations"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (164 commits)
  KVM: selftests: Avoid using forced target for generating arm64 headers
  tools headers arm64: Fix references to top srcdir in Makefile
  KVM: arm64: Add tracepoint for MMIO accesses where ISV==0
  KVM: arm64: selftest: Perform ISB before reading PAR_EL1
  KVM: arm64: selftest: Add the missing .guest_prepare()
  KVM: arm64: Always invalidate TLB for stage-2 permission faults
  KVM: x86: Service NMI requests after PMI requests in VM-Enter path
  KVM: arm64: Handle AArch32 SPSR_{irq,abt,und,fiq} as RAZ/WI
  KVM: arm64: Do not let a L1 hypervisor access the *32_EL2 sysregs
  KVM: arm64: Refine _EL2 system register list that require trap reinjection
  arm64: Add missing _EL2 encodings
  arm64: Add missing _EL12 encodings
  KVM: selftests: aarch64: vPMU test for validating user accesses
  KVM: selftests: aarch64: vPMU register test for unimplemented counters
  KVM: selftests: aarch64: vPMU register test for implemented counters
  KVM: selftests: aarch64: Introduce vpmu_counter_access test
  tools: Import arm_pmuv3.h
  KVM: arm64: PMU: Allow userspace to limit PMCR_EL0.N for the guest
  KVM: arm64: Sanitize PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} before first run
  KVM: arm64: Add {get,set}_user for PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR}
  ...
2023-11-02 15:45:15 -10:00
Oliver Upton
123f42f0ad Merge branch kvm-arm64/pmu_pmcr_n into kvmarm/next
* kvm-arm64/pmu_pmcr_n:
  : User-defined PMC limit, courtesy Raghavendra Rao Ananta
  :
  : Certain VMMs may want to reserve some PMCs for host use while running a
  : KVM guest. This was a bit difficult before, as KVM advertised all
  : supported counters to the guest. Userspace can now limit the number of
  : advertised PMCs by writing to PMCR_EL0.N, as KVM's sysreg and PMU
  : emulation enforce the specified limit for handling guest accesses.
  KVM: selftests: aarch64: vPMU test for validating user accesses
  KVM: selftests: aarch64: vPMU register test for unimplemented counters
  KVM: selftests: aarch64: vPMU register test for implemented counters
  KVM: selftests: aarch64: Introduce vpmu_counter_access test
  tools: Import arm_pmuv3.h
  KVM: arm64: PMU: Allow userspace to limit PMCR_EL0.N for the guest
  KVM: arm64: Sanitize PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} before first run
  KVM: arm64: Add {get,set}_user for PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR}
  KVM: arm64: PMU: Set PMCR_EL0.N for vCPU based on the associated PMU
  KVM: arm64: PMU: Add a helper to read a vCPU's PMCR_EL0
  KVM: arm64: Select default PMU in KVM_ARM_VCPU_INIT handler
  KVM: arm64: PMU: Introduce helpers to set the guest's PMU

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-30 20:24:19 +00:00
Oliver Upton
a87a36436c Merge branch kvm-arm64/writable-id-regs into kvmarm/next
* kvm-arm64/writable-id-regs:
  : Writable ID registers, courtesy of Jing Zhang
  :
  : This series significantly expands the architectural feature set that
  : userspace can manipulate via the ID registers. A new ioctl is defined
  : that makes the mutable fields in the ID registers discoverable to
  : userspace.
  KVM: selftests: Avoid using forced target for generating arm64 headers
  tools headers arm64: Fix references to top srcdir in Makefile
  KVM: arm64: selftests: Test for setting ID register from usersapce
  tools headers arm64: Update sysreg.h with kernel sources
  KVM: selftests: Generate sysreg-defs.h and add to include path
  perf build: Generate arm64's sysreg-defs.h and add to include path
  tools: arm64: Add a Makefile for generating sysreg-defs.h
  KVM: arm64: Document vCPU feature selection UAPIs
  KVM: arm64: Allow userspace to change ID_AA64ZFR0_EL1
  KVM: arm64: Allow userspace to change ID_AA64PFR0_EL1
  KVM: arm64: Allow userspace to change ID_AA64MMFR{0-2}_EL1
  KVM: arm64: Allow userspace to change ID_AA64ISAR{0-2}_EL1
  KVM: arm64: Bump up the default KVM sanitised debug version to v8p8
  KVM: arm64: Reject attempts to set invalid debug arch version
  KVM: arm64: Advertise selected DebugVer in DBGDIDR.Version
  KVM: arm64: Use guest ID register values for the sake of emulation
  KVM: arm64: Document KVM_ARM_GET_REG_WRITABLE_MASKS
  KVM: arm64: Allow userspace to get the writable masks for feature ID registers

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-30 20:21:09 +00:00
Oliver Upton
54b44ad26c Merge branch kvm-arm64/sgi-injection into kvmarm/next
* kvm-arm64/sgi-injection:
  : vSGI injection improvements + fixes, courtesy Marc Zyngier
  :
  : Avoid linearly searching for vSGI targets using a compressed MPIDR to
  : index a cache. While at it, fix some egregious bugs in KVM's mishandling
  : of vcpuid (user-controlled value) and vcpu_idx.
  KVM: arm64: Clarify the ordering requirements for vcpu/RD creation
  KVM: arm64: vgic-v3: Optimize affinity-based SGI injection
  KVM: arm64: Fast-track kvm_mpidr_to_vcpu() when mpidr_data is available
  KVM: arm64: Build MPIDR to vcpu index cache at runtime
  KVM: arm64: Simplify kvm_vcpu_get_mpidr_aff()
  KVM: arm64: Use vcpu_idx for invalidation tracking
  KVM: arm64: vgic: Use vcpu_idx for the debug information
  KVM: arm64: vgic-v2: Use cpuid from userspace as vcpu_id
  KVM: arm64: vgic-v3: Refactor GICv3 SGI generation
  KVM: arm64: vgic-its: Treat the collection target address as a vcpu_id
  KVM: arm64: vgic: Make kvm_vgic_inject_irq() take a vcpu pointer

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-30 20:19:13 +00:00
Oliver Upton
df26b77915 Merge branch kvm-arm64/stage2-vhe-load into kvmarm/next
* kvm-arm64/stage2-vhe-load:
  : Setup stage-2 MMU from vcpu_load() for VHE
  :
  : Unlike nVHE, there is no need to switch the stage-2 MMU around on guest
  : entry/exit in VHE mode as the host is running at EL2. Despite this KVM
  : reloads the stage-2 on every guest entry, which is needless.
  :
  : This series moves the setup of the stage-2 MMU context to vcpu_load()
  : when running in VHE mode. This is likely to be a win across the board,
  : but also allows us to remove an ISB on the guest entry path for systems
  : with one of the speculative AT errata.
  KVM: arm64: Move VTCR_EL2 into struct s2_mmu
  KVM: arm64: Load the stage-2 MMU context in kvm_vcpu_load_vhe()
  KVM: arm64: Rename helpers for VHE vCPU load/put
  KVM: arm64: Reload stage-2 for VMID change on VHE
  KVM: arm64: Restore the stage-2 context in VHE's __tlb_switch_to_host()
  KVM: arm64: Don't zero VTTBR in __tlb_switch_to_host()

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-30 20:18:56 +00:00
Oliver Upton
25a35c1a3d Merge branch kvm-arm64/smccc-filter-cleanups into kvmarm/next
* kvm-arm64/smccc-filter-cleanups:
  : Cleanup the management of KVM's SMCCC maple tree
  :
  : Avoid the cost of maintaining the SMCCC filter maple tree if userspace
  : hasn't writen a rule to the filter. While at it, rip out the now
  : unnecessary VM flag to indicate whether or not the SMCCC filter was
  : configured.
  KVM: arm64: Use mtree_empty() to determine if SMCCC filter configured
  KVM: arm64: Only insert reserved ranges when SMCCC filter is used
  KVM: arm64: Add a predicate for testing if SMCCC filter is configured

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-30 20:18:37 +00:00
Raghavendra Rao Ananta
4d20debf9c KVM: arm64: PMU: Set PMCR_EL0.N for vCPU based on the associated PMU
The number of PMU event counters is indicated in PMCR_EL0.N.
For a vCPU with PMUv3 configured, the value is set to the same
value as the current PE on every vCPU reset.  Unless the vCPU is
pinned to PEs that has the PMU associated to the guest from the
initial vCPU reset, the value might be different from the PMU's
PMCR_EL0.N on heterogeneous PMU systems.

Fix this by setting the vCPU's PMCR_EL0.N to the PMU's PMCR_EL0.N
value. Track the PMCR_EL0.N per guest, as only one PMU can be set
for the guest (PMCR_EL0.N must be the same for all vCPUs of the
guest), and it is convenient for updating the value.

To achieve this, the patch introduces a helper,
kvm_arm_pmu_get_max_counters(), that reads the maximum number of
counters from the arm_pmu associated to the VM. Make the function
global as upcoming patches will be interested to know the value
while setting the PMCR.N of the guest from userspace.

KVM does not yet support userspace modifying PMCR_EL0.N.
The following patch will add support for that.

Reviewed-by: Sebastian Ott <sebott@redhat.com>
Co-developed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Link: https://lore.kernel.org/r/20231020214053.2144305-5-rananta@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-24 22:59:30 +00:00
Marc Zyngier
fe49fd940e KVM: arm64: Move VTCR_EL2 into struct s2_mmu
We currently have a global VTCR_EL2 value for each guest, even
if the guest uses NV. This implies that the guest's own S2 must
fit in the host's. This is odd, for multiple reasons:

- the PARange values and the number of IPA bits don't necessarily
  match: you can have 33 bits of IPA space, and yet you can only
  describe 32 or 36 bits of PARange

- When userspace set the IPA space, it creates a contract with the
  kernel saying "this is the IPA space I'm prepared to handle".
  At no point does it constraint the guest's own IPA space as
  long as the guest doesn't try to use a [I]PA outside of the
  IPA space set by userspace

- We don't even try to hide the value of ID_AA64MMFR0_EL1.PARange.

And then there is the consequence of the above: if a guest tries
to create a S2 that has for input address something that is larger
than the IPA space defined by the host, we inject a fatal exception.

This is no good. For all intent and purposes, a guest should be
able to have the S2 it really wants, as long as the *output* address
of that S2 isn't outside of the IPA space.

For that, we need to have a per-s2_mmu VTCR_EL2 setting, which
allows us to represent the full PARange. Move the vctr field into
the s2_mmu structure, which has no impact whatsoever, except for NV.

Note that once we are able to override ID_AA64MMFR0_EL1.PARange
from userspace, we'll also be able to restrict the size of the
shadow S2 that NV uses.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231012205108.3937270-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-23 18:48:46 +00:00
Oliver Upton
27cde4c0fe KVM: arm64: Rename helpers for VHE vCPU load/put
The names for the helpers we expose to the 'generic' KVM code are a bit
imprecise; we switch the EL0 + EL1 sysreg context and setup trap
controls that do not need to change for every guest entry/exit. Rename +
shuffle things around a bit in preparation for loading the stage-2 MMU
context on vcpu_load().

Link: https://lore.kernel.org/r/20231018233212.2888027-5-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-20 17:52:01 +00:00
Marc Zyngier
5eba523e1e KVM: arm64: Reload stage-2 for VMID change on VHE
Naturally, a change to the VMID for an MMU implies a new value for
VTTBR. Reload on VMID change in anticipation of loading stage-2 on
vcpu_load() instead of every guest entry.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231018233212.2888027-4-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-20 17:52:01 +00:00
Mark Rutland
d8569fba13 arm64: kvm: Use cpus_have_final_cap() explicitly
Much of the arm64 KVM code uses cpus_have_const_cap() to check for
cpucaps, but this is unnecessary and it would be preferable to use
cpus_have_final_cap().

For historical reasons, cpus_have_const_cap() is more complicated than
it needs to be. Before cpucaps are finalized, it will perform a bitmap
test of the system_cpucaps bitmap, and once cpucaps are finalized it
will use an alternative branch. This used to be necessary to handle some
race conditions in the window between cpucap detection and the
subsequent patching of alternatives and static branches, where different
branches could be out-of-sync with one another (or w.r.t. alternative
sequences). Now that we use alternative branches instead of static
branches, these are all patched atomically w.r.t. one another, and there
are only a handful of cases that need special care in the window between
cpucap detection and alternative patching.

Due to the above, it would be nice to remove cpus_have_const_cap(), and
migrate callers over to alternative_has_cap_*(), cpus_have_final_cap(),
or cpus_have_cap() depending on when their requirements. This will
remove redundant instructions and improve code generation, and will make
it easier to determine how each callsite will behave before, during, and
after alternative patching.

KVM is initialized after cpucaps have been finalized and alternatives
have been patched. Since commit:

  d86de40dec ("arm64: cpufeature: upgrade hyp caps to final")

... use of cpus_have_const_cap() in hyp code is automatically converted
to use cpus_have_final_cap():

| static __always_inline bool cpus_have_const_cap(int num)
| {
| 	if (is_hyp_code())
| 		return cpus_have_final_cap(num);
| 	else if (system_capabilities_finalized())
| 		return __cpus_have_const_cap(num);
| 	else
| 		return cpus_have_cap(num);
| }

Thus, converting hyp code to use cpus_have_final_cap() directly will not
result in any functional change.

Non-hyp KVM code is also not executed until cpucaps have been finalized,
and it would be preferable to extent the same treatment to this code and
use cpus_have_final_cap() directly.

This patch converts instances of cpus_have_const_cap() in KVM-only code
over to cpus_have_final_cap(). As all of this code runs after cpucaps
have been finalized, there should be no functional change as a result of
this patch, but the redundant instructions generated by
cpus_have_const_cap() will be removed from the non-hyp KVM code.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-10-16 12:57:56 +01:00
Oliver Upton
4202bcac5e KVM: arm64: Use mtree_empty() to determine if SMCCC filter configured
The smccc_filter maple tree is only populated if userspace attempted to
configure it. Use the state of the maple tree to determine if the filter
has been configured, eliminating the VM flag.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231004234947.207507-4-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-05 09:33:15 +00:00
Jing Zhang
3f9cd0ca84 KVM: arm64: Allow userspace to get the writable masks for feature ID registers
While the Feature ID range is well defined and pretty large, it isn't
inconceivable that the architecture will eventually grow some other
ranges that will need to similarly be described to userspace.

Add a VM ioctl to allow userspace to get writable masks for feature ID
registers in below system register space:
op0 = 3, op1 = {0, 1, 3}, CRn = 0, CRm = {0 - 7}, op2 = {0 - 7}
This is used to support mix-and-match userspace and kernels for writable
ID registers, where userspace may want to know upfront whether it can
actually tweak the contents of an idreg or not.

Add a new capability (KVM_CAP_ARM_SUPPORTED_FEATURE_ID_RANGES) that
returns a bitmap of the valid ranges, which can subsequently be
retrieved, one at a time by setting the index of the set bit as the
range identifier.

Suggested-by: Marc Zyngier <maz@kernel.org>
Suggested-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231003230408.3405722-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-10-04 17:09:39 +00:00
Marc Zyngier
5544750efd KVM: arm64: Build MPIDR to vcpu index cache at runtime
The MPIDR_EL1 register contains a unique value that identifies
the CPU. The only problem with it is that it is stupidly large
(32 bits, once the useless stuff is removed).

Trying to obtain a vcpu from an MPIDR value is a fairly common,
yet costly operation: we iterate over all the vcpus until we
find the correct one. While this is cheap for small VMs, it is
pretty expensive on large ones, specially if you are trying to
get to the one that's at the end of the list...

In order to help with this, it is important to realise that
the MPIDR values are actually structured, and that implementations
tend to use a small number of significant bits in the 32bit space.

We can use this fact to our advantage by computing a small hash
table that uses the "compression" of the significant MPIDR bits
as an index, giving us the vcpu index as a result.

Given that the MPIDR values can be supplied by userspace, and
that an evil VMM could decide to make *all* bits significant,
resulting in a 4G-entry table, we only use this method if the
resulting table fits in a single page. Otherwise, we fallback
to the good old iterative method.

Nothing uses that table just yet, but keep your eyes peeled.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Tested-by: Joey Gouly <joey.gouly@arm.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230927090911.3355209-9-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-30 18:15:43 +00:00
Oliver Upton
1de10b7d13 KVM: arm64: Get rid of vCPU-scoped feature bitmap
The vCPU-scoped feature bitmap was left in place a couple of releases
ago in case the change to VM-scoped vCPU features broke anyone. Nobody
has complained and the interop between VM and vCPU bitmaps is pretty
gross. Throw it out.

Link: https://lore.kernel.org/r/20230920195036.1169791-9-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21 18:13:29 +00:00
Oliver Upton
3d4b2a4cdd KVM: arm64: Remove unused return value from kvm_reset_vcpu()
Get rid of the return value for kvm_reset_vcpu() as there are no longer
any cases where it returns a nonzero value.

Link: https://lore.kernel.org/r/20230920195036.1169791-8-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-09-21 18:13:29 +00:00
Marc Zyngier
1f66f1246b Merge branch kvm-arm64/6.6/misc into kvmarm-master/next
* kvm-arm64/6.6/misc:
  : .
  : Misc KVM/arm64 updates for 6.6:
  :
  : - Don't unnecessary align non-stack allocations in the EL2 VA space
  :
  : - Drop HCR_VIRT_EXCP_MASK, which was never used...
  :
  : - Don't use smp_processor_id() in kvm_arch_vcpu_load(),
  :   but the cpu parameter instead
  :
  : - Drop redundant call to kvm_set_pfn_accessed() in user_mem_abort()
  :
  : - Remove prototypes without implementations
  : .
  KVM: arm64: Remove size-order align in the nVHE hyp private VA range
  KVM: arm64: Remove unused declarations
  KVM: arm64: Remove redundant kvm_set_pfn_accessed() from user_mem_abort()
  KVM: arm64: Drop HCR_VIRT_EXCP_MASK
  KVM: arm64: Use the known cpu id instead of smp_processor_id()

Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-08-28 09:30:32 +01:00
Marc Zyngier
50a40ff7d3 Merge branch kvm-arm64/6.6/pmu-fixes into kvmarm-master/next
* kvm-arm64/6.6/pmu-fixes:
  : .
  : Another set of PMU fixes, coutrtesy of Reiji Watanabe.
  : From the cover letter:
  :
  : "This series fixes a couple of PMUver related handling of
  : vPMU support.
  :
  : On systems where the PMUVer is not uniform across all PEs,
  : KVM currently does not advertise PMUv3 to the guest,
  : even if userspace successfully runs KVM_ARM_VCPU_INIT with
  : KVM_ARM_VCPU_PMU_V3."
  :
  : Additionally, a fix for an obscure counter oversubscription
  : issue happening when the hsot profines the guest's EL0.
  : .
  KVM: arm64: pmu: Guard PMU emulation definitions with CONFIG_KVM
  KVM: arm64: pmu: Resync EL0 state on counter rotation
  KVM: arm64: PMU: Don't advertise STALL_SLOT_{FRONTEND,BACKEND}
  KVM: arm64: PMU: Don't advertise the STALL_SLOT event
  KVM: arm64: PMU: Avoid inappropriate use of host's PMUVer
  KVM: arm64: PMU: Disallow vPMU on non-uniform PMUVer

Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-08-28 09:29:11 +01:00
Marc Zyngier
d58335d10f Merge branch kvm-arm64/tlbi-range into kvmarm-master/next
* kvm-arm64/tlbi-range:
  : .
  : FEAT_TLBIRANGE support, courtesy of Raghavendra Rao Ananta.
  : From the cover letter:
  :
  : "In certain code paths, KVM/ARM currently invalidates the entire VM's
  : page-tables instead of just invalidating a necessary range. For example,
  : when collapsing a table PTE to a block PTE, instead of iterating over
  : each PTE and flushing them, KVM uses 'vmalls12e1is' TLBI operation to
  : flush all the entries. This is inefficient since the guest would have
  : to refill the TLBs again, even for the addresses that aren't covered
  : by the table entry. The performance impact would scale poorly if many
  : addresses in the VM is going through this remapping.
  :
  : For architectures that implement FEAT_TLBIRANGE, KVM can replace such
  : inefficient paths by performing the invalidations only on the range of
  : addresses that are in scope. This series tries to achieve the same in
  : the areas of stage-2 map, unmap and write-protecting the pages."
  : .
  KVM: arm64: Use TLBI range-based instructions for unmap
  KVM: arm64: Invalidate the table entries upon a range
  KVM: arm64: Flush only the memslot after write-protect
  KVM: arm64: Implement kvm_arch_flush_remote_tlbs_range()
  KVM: arm64: Define kvm_tlb_flush_vmid_range()
  KVM: arm64: Implement __kvm_tlb_flush_vmid_range()
  arm64: tlb: Implement __flush_s2_tlb_range_op()
  arm64: tlb: Refactor the core flush algorithm of __flush_tlb_range
  KVM: Move kvm_arch_flush_remote_tlbs_memslot() to common code
  KVM: Allow range-based TLB invalidation from common code
  KVM: Remove CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL
  KVM: arm64: Use kvm_arch_flush_remote_tlbs()
  KVM: Declare kvm_arch_flush_remote_tlbs() globally
  KVM: Rename kvm_arch_flush_remote_tlb() to kvm_arch_flush_remote_tlbs()

Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-08-28 09:29:02 +01:00
Marc Zyngier
c1907626dd Merge branch kvm-arm64/nv-trap-forwarding into kvmarm-master/next
* kvm-arm64/nv-trap-forwarding: (30 commits)
  : .
  : This implements the so called "trap forwarding" infrastructure, which
  : gets used when we take a trap from an L2 guest and that the L1 guest
  : wants to see the trap for itself.
  : .
  KVM: arm64: nv: Add trap description for SPSR_EL2 and ELR_EL2
  KVM: arm64: nv: Select XARRAY_MULTI to fix build error
  KVM: arm64: nv: Add support for HCRX_EL2
  KVM: arm64: Move HCRX_EL2 switch to load/put on VHE systems
  KVM: arm64: nv: Expose FGT to nested guests
  KVM: arm64: nv: Add switching support for HFGxTR/HDFGxTR
  KVM: arm64: nv: Expand ERET trap forwarding to handle FGT
  KVM: arm64: nv: Add SVC trap forwarding
  KVM: arm64: nv: Add trap forwarding for HDFGxTR_EL2
  KVM: arm64: nv: Add trap forwarding for HFGITR_EL2
  KVM: arm64: nv: Add trap forwarding for HFGxTR_EL2
  KVM: arm64: nv: Add fine grained trap forwarding infrastructure
  KVM: arm64: nv: Add trap forwarding for CNTHCTL_EL2
  KVM: arm64: nv: Add trap forwarding for MDCR_EL2
  KVM: arm64: nv: Expose FEAT_EVT to nested guests
  KVM: arm64: nv: Add trap forwarding for HCR_EL2
  KVM: arm64: nv: Add trap forwarding infrastructure
  KVM: arm64: Restructure FGT register switching
  KVM: arm64: nv: Add FGT registers
  KVM: arm64: Add missing HCR_EL2 trap bits
  ...

Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-08-28 09:28:53 +01:00
Marc Zyngier
b1f778a223 KVM: arm64: pmu: Resync EL0 state on counter rotation
Huang Shijie reports that, when profiling a guest from the host
with a number of events that exceeds the number of available
counters, the reported counts are wildly inaccurate. Without
the counter oversubscription, the reported counts are correct.

Their investigation indicates that upon counter rotation (which
takes place on the back of a timer interrupt), we fail to
re-apply the guest EL0 enabling, leading to the counting of host
events instead of guest events.

In order to solve this, add yet another hook between the host PMU
driver and KVM, re-applying the guest EL0 configuration if the
right conditions apply (the host is VHE, we are in interrupt
context, and we interrupted a running vcpu). This triggers a new
vcpu request which will apply the correct configuration on guest
reentry.

With this, we have the correct counts, even when the counters are
oversubscribed.

Reported-by: Huang Shijie <shijie@os.amperecomputing.com>
Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Tested_by: Huang Shijie <shijie@os.amperecomputing.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230809013953.7692-1-shijie@os.amperecomputing.com
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20230820090108.177817-1-maz@kernel.org
2023-08-22 13:35:51 +01:00
Marc Zyngier
03fb54d0aa KVM: arm64: nv: Add support for HCRX_EL2
HCRX_EL2 has an interesting effect on HFGITR_EL2, as it conditions
the traps of TLBI*nXS.

Expand the FGT support to add a new Fine Grained Filter that will
get checked when the instruction gets trapped, allowing the shadow
register to override the trap as needed.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Jing Zhang <jingzhangos@google.com>
Link: https://lore.kernel.org/r/20230815183903.2735724-29-maz@kernel.org
2023-08-17 10:00:28 +01:00
Marc Zyngier
e58ec47bf6 KVM: arm64: nv: Add trap forwarding infrastructure
A significant part of what a NV hypervisor needs to do is to decide
whether a trap from a L2+ guest has to be forwarded to a L1 guest
or handled locally. This is done by checking for the trap bits that
the guest hypervisor has set and acting accordingly, as described by
the architecture.

A previous approach was to sprinkle a bunch of checks in all the
system register accessors, but this is pretty error prone and doesn't
help getting an overview of what is happening.

Instead, implement a set of global tables that describe a trap bit,
combinations of trap bits, behaviours on trap, and what bits must
be evaluated on a system register trap.

Although this is painful to describe, this allows to specify each
and every control bit in a static manner. To make it efficient,
the table is inserted in an xarray that is global to the system,
and checked each time we trap a system register while running
a L2 guest.

Add the basic infrastructure for now, while additional patches will
implement configuration registers.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Jing Zhang <jingzhangos@google.com>
Reviewed-by: Miguel Luis <miguel.luis@oracle.com>
Link: https://lore.kernel.org/r/20230815183903.2735724-15-maz@kernel.org
2023-08-17 10:00:27 +01:00
Marc Zyngier
50d2fe4648 KVM: arm64: nv: Add FGT registers
Add the 5 registers covering FEAT_FGT. The AMU-related registers
are currently left out as we don't have a plan for them. Yet.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Miguel Luis <miguel.luis@oracle.com>
Reviewed-by: Jing Zhang <jingzhangos@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230815183903.2735724-13-maz@kernel.org
2023-08-17 10:00:27 +01:00
Raghavendra Rao Ananta
c42b6f0b1c KVM: arm64: Implement kvm_arch_flush_remote_tlbs_range()
Implement kvm_arch_flush_remote_tlbs_range() for arm64
to invalidate the given range in the TLB.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230811045127.3308641-12-rananta@google.com
2023-08-17 09:40:35 +01:00
Raghavendra Rao Ananta
32121c8138 KVM: arm64: Use kvm_arch_flush_remote_tlbs()
Stop depending on CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL and opt to
standardize on kvm_arch_flush_remote_tlbs() since it avoids
duplicating the generic TLB stats across architectures that implement
their own remote TLB flush.

This adds an extra function call to the ARM64 kvm_flush_remote_tlbs()
path, but that is a small cost in comparison to flushing remote TLBs.

In addition, instead of just incrementing remote_tlb_flush_requests
stat, the generic interface would also increment the
remote_tlb_flush stat.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230811045127.3308641-4-rananta@google.com
2023-08-17 09:35:14 +01:00
Yue Haibing
a6b33d009f KVM: arm64: Remove unused declarations
Commit 53692908b0 ("KVM: arm/arm64: vgic: Fix source vcpu issues for GICv2 SGI")
removed vgic_v2_set_npie()/vgic_v3_set_npie() but not the declarations.
Commit 29eb5a3c57 ("KVM: arm64: Handle PtrAuth traps early") left behind
kvm_arm_vcpu_ptrauth_trap(), remove it.
Commit 2a0c343386 ("KVM: arm64: Initialize trap registers for protected VMs")
declared but never implemented kvm_init_protected_traps() and
commit cf5d318865 ("arm/arm64: KVM: Turn off vcpus on PSCI shutdown/reboot")
declared but never implemented force_vm_exit().

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Zenghui Yu <zenghui.yu@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230814140636.45988-1-yuehaibing@huawei.com
2023-08-15 20:27:32 +01:00
Marc Zyngier
319d1a957c Merge branch kvm-arm64/6.6/generic-vcpu into kvmarm-master/next
* kvm-arm64/6.6/generic-vcpu:
  : .
  : Cleanup the obsolete vcpu target abstraction, courtesy of Oliver.
  : From the cover letter:
  :
  : "kvm_vcpu_init::target is quite useless at this point. We don't do any
  : uarch-specific emulation in the first place, and require userspace
  : select the 'generic' vCPU target on all but a few implementations.
  :
  : Small series to (1) clean up usage of the target value in the kernel and
  : (2) switch to the 'generic' target on implementations that previously
  : had their own target values. The implementation-specific values are
  : still tolerated, though, to avoid UAPI breakage."
  : .
  KVM: arm64: Always return generic v8 as the preferred target
  KVM: arm64: Replace vCPU target with a configuration flag
  KVM: arm64: Remove pointless check for changed init target
  KVM: arm64: Delete pointless switch statement in kvm_reset_vcpu()

Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-07-28 12:03:45 +01:00
Marc Zyngier
b321c31c9b KVM: arm64: vgic-v4: Make the doorbell request robust w.r.t preemption
Xiang reports that VMs occasionally fail to boot on GICv4.1 systems when
running a preemptible kernel, as it is possible that a vCPU is blocked
without requesting a doorbell interrupt.

The issue is that any preemption that occurs between vgic_v4_put() and
schedule() on the block path will mark the vPE as nonresident and *not*
request a doorbell irq. This occurs because when the vcpu thread is
resumed on its way to block, vcpu_load() will make the vPE resident
again. Once the vcpu actually blocks, we don't request a doorbell
anymore, and the vcpu won't be woken up on interrupt delivery.

Fix it by tracking that we're entering WFI, and key the doorbell
request on that flag. This allows us not to make the vPE resident
when going through a preempt/schedule cycle, meaning we don't lose
any state.

Cc: stable@vger.kernel.org
Fixes: 8e01d9a396 ("KVM: arm64: vgic-v4: Move the GICv4 residency flow to be driven by vcpu_load/put")
Reported-by: Xiang Chen <chenxiang66@hisilicon.com>
Suggested-by: Zenghui Yu <yuzenghui@huawei.com>
Tested-by: Xiang Chen <chenxiang66@hisilicon.com>
Co-developed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Zenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/r/20230713070657.3873244-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-07-13 22:23:34 +00:00
Oliver Upton
5346f7e13e KVM: arm64: Always return generic v8 as the preferred target
Userspace selecting an implementation-specific vCPU target has been
completely useless for a very long time. Let's go whole hog and start
returning the generic v8 target across all implementations as the
preferred target.

Uphold the pre-existing behavior by tolerating either the generic target
or an implementation-specific target if the vCPU happens to be running
on one of the lucky few parts.

Acked-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230710193140.1706399-5-oliver.upton@linux.dev
2023-07-11 09:40:52 +01:00
Oliver Upton
ef98406036 KVM: arm64: Replace vCPU target with a configuration flag
The value of kvm_vcpu_arch::target has been used to determine if a vCPU
has actually been initialized. Storing this as an integer is needless at
this point, as KVM doesn't do any microarch-specific emulation in the
first place. Instead, all we care about is whether or not the vCPU has
been initialized.

Delete the field in favor of a vCPU configuration flag indicating if
KVM_ARM_VCPU_INIT has completed for the vCPU.

Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230710193140.1706399-4-oliver.upton@linux.dev
2023-07-11 09:40:52 +01:00
Linus Torvalds
e8069f5a8e ARM64:
* Eager page splitting optimization for dirty logging, optionally
   allowing for a VM to avoid the cost of hugepage splitting in the stage-2
   fault path.
 
 * Arm FF-A proxy for pKVM, allowing a pKVM host to safely interact with
   services that live in the Secure world. pKVM intervenes on FF-A calls
   to guarantee the host doesn't misuse memory donated to the hyp or a
   pKVM guest.
 
 * Support for running the split hypervisor with VHE enabled, known as
   'hVHE' mode. This is extremely useful for testing the split
   hypervisor on VHE-only systems, and paves the way for new use cases
   that depend on having two TTBRs available at EL2.
 
 * Generalized framework for configurable ID registers from userspace.
   KVM/arm64 currently prevents arbitrary CPU feature set configuration
   from userspace, but the intent is to relax this limitation and allow
   userspace to select a feature set consistent with the CPU.
 
 * Enable the use of Branch Target Identification (FEAT_BTI) in the
   hypervisor.
 
 * Use a separate set of pointer authentication keys for the hypervisor
   when running in protected mode, as the host is untrusted at runtime.
 
 * Ensure timer IRQs are consistently released in the init failure
   paths.
 
 * Avoid trapping CTR_EL0 on systems with Enhanced Virtualization Traps
   (FEAT_EVT), as it is a register commonly read from userspace.
 
 * Erratum workaround for the upcoming AmpereOne part, which has broken
   hardware A/D state management.
 
 RISC-V:
 
 * Redirect AMO load/store misaligned traps to KVM guest
 
 * Trap-n-emulate AIA in-kernel irqchip for KVM guest
 
 * Svnapot support for KVM Guest
 
 s390:
 
 * New uvdevice secret API
 
 * CMM selftest and fixes
 
 * fix racy access to target CPU for diag 9c
 
 x86:
 
 * Fix missing/incorrect #GP checks on ENCLS
 
 * Use standard mmu_notifier hooks for handling APIC access page
 
 * Drop now unnecessary TR/TSS load after VM-Exit on AMD
 
 * Print more descriptive information about the status of SEV and SEV-ES during
   module load
 
 * Add a test for splitting and reconstituting hugepages during and after
   dirty logging
 
 * Add support for CPU pinning in demand paging test
 
 * Add support for AMD PerfMonV2, with a variety of cleanups and minor fixes
   included along the way
 
 * Add a "nx_huge_pages=never" option to effectively avoid creating NX hugepage
   recovery threads (because nx_huge_pages=off can be toggled at runtime)
 
 * Move handling of PAT out of MTRR code and dedup SVM+VMX code
 
 * Fix output of PIC poll command emulation when there's an interrupt
 
 * Add a maintainer's handbook to document KVM x86 processes, preferred coding
   style, testing expectations, etc.
 
 * Misc cleanups, fixes and comments
 
 Generic:
 
 * Miscellaneous bugfixes and cleanups
 
 Selftests:
 
 * Generate dependency files so that partial rebuilds work as expected
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM64:

   - Eager page splitting optimization for dirty logging, optionally
     allowing for a VM to avoid the cost of hugepage splitting in the
     stage-2 fault path.

   - Arm FF-A proxy for pKVM, allowing a pKVM host to safely interact
     with services that live in the Secure world. pKVM intervenes on
     FF-A calls to guarantee the host doesn't misuse memory donated to
     the hyp or a pKVM guest.

   - Support for running the split hypervisor with VHE enabled, known as
     'hVHE' mode. This is extremely useful for testing the split
     hypervisor on VHE-only systems, and paves the way for new use cases
     that depend on having two TTBRs available at EL2.

   - Generalized framework for configurable ID registers from userspace.
     KVM/arm64 currently prevents arbitrary CPU feature set
     configuration from userspace, but the intent is to relax this
     limitation and allow userspace to select a feature set consistent
     with the CPU.

   - Enable the use of Branch Target Identification (FEAT_BTI) in the
     hypervisor.

   - Use a separate set of pointer authentication keys for the
     hypervisor when running in protected mode, as the host is untrusted
     at runtime.

   - Ensure timer IRQs are consistently released in the init failure
     paths.

   - Avoid trapping CTR_EL0 on systems with Enhanced Virtualization
     Traps (FEAT_EVT), as it is a register commonly read from userspace.

   - Erratum workaround for the upcoming AmpereOne part, which has
     broken hardware A/D state management.

  RISC-V:

   - Redirect AMO load/store misaligned traps to KVM guest

   - Trap-n-emulate AIA in-kernel irqchip for KVM guest

   - Svnapot support for KVM Guest

  s390:

   - New uvdevice secret API

   - CMM selftest and fixes

   - fix racy access to target CPU for diag 9c

  x86:

   - Fix missing/incorrect #GP checks on ENCLS

   - Use standard mmu_notifier hooks for handling APIC access page

   - Drop now unnecessary TR/TSS load after VM-Exit on AMD

   - Print more descriptive information about the status of SEV and
     SEV-ES during module load

   - Add a test for splitting and reconstituting hugepages during and
     after dirty logging

   - Add support for CPU pinning in demand paging test

   - Add support for AMD PerfMonV2, with a variety of cleanups and minor
     fixes included along the way

   - Add a "nx_huge_pages=never" option to effectively avoid creating NX
     hugepage recovery threads (because nx_huge_pages=off can be toggled
     at runtime)

   - Move handling of PAT out of MTRR code and dedup SVM+VMX code

   - Fix output of PIC poll command emulation when there's an interrupt

   - Add a maintainer's handbook to document KVM x86 processes,
     preferred coding style, testing expectations, etc.

   - Misc cleanups, fixes and comments

  Generic:

   - Miscellaneous bugfixes and cleanups

  Selftests:

   - Generate dependency files so that partial rebuilds work as
     expected"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (153 commits)
  Documentation/process: Add a maintainer handbook for KVM x86
  Documentation/process: Add a label for the tip tree handbook's coding style
  KVM: arm64: Fix misuse of KVM_ARM_VCPU_POWER_OFF bit index
  RISC-V: KVM: Remove unneeded semicolon
  RISC-V: KVM: Allow Svnapot extension for Guest/VM
  riscv: kvm: define vcpu_sbi_ext_pmu in header
  RISC-V: KVM: Expose IMSIC registers as attributes of AIA irqchip
  RISC-V: KVM: Add in-kernel virtualization of AIA IMSIC
  RISC-V: KVM: Expose APLIC registers as attributes of AIA irqchip
  RISC-V: KVM: Add in-kernel emulation of AIA APLIC
  RISC-V: KVM: Implement device interface for AIA irqchip
  RISC-V: KVM: Skeletal in-kernel AIA irqchip support
  RISC-V: KVM: Set kvm_riscv_aia_nr_hgei to zero
  RISC-V: KVM: Add APLIC related defines
  RISC-V: KVM: Add IMSIC related defines
  RISC-V: KVM: Implement guest external interrupt line management
  KVM: x86: Remove PRIx* definitions as they are solely for user space
  s390/uv: Update query for secret-UVCs
  s390/uv: replace scnprintf with sysfs_emit
  s390/uvdevice: Add 'Lock Secret Store' UVC
  ...
2023-07-03 15:32:22 -07:00
Paolo Bonzini
cc744042d9 KVM/arm64 updates for 6.5
- Eager page splitting optimization for dirty logging, optionally
    allowing for a VM to avoid the cost of block splitting in the stage-2
    fault path.
 
  - Arm FF-A proxy for pKVM, allowing a pKVM host to safely interact with
    services that live in the Secure world. pKVM intervenes on FF-A calls
    to guarantee the host doesn't misuse memory donated to the hyp or a
    pKVM guest.
 
  - Support for running the split hypervisor with VHE enabled, known as
    'hVHE' mode. This is extremely useful for testing the split
    hypervisor on VHE-only systems, and paves the way for new use cases
    that depend on having two TTBRs available at EL2.
 
  - Generalized framework for configurable ID registers from userspace.
    KVM/arm64 currently prevents arbitrary CPU feature set configuration
    from userspace, but the intent is to relax this limitation and allow
    userspace to select a feature set consistent with the CPU.
 
  - Enable the use of Branch Target Identification (FEAT_BTI) in the
    hypervisor.
 
  - Use a separate set of pointer authentication keys for the hypervisor
    when running in protected mode, as the host is untrusted at runtime.
 
  - Ensure timer IRQs are consistently released in the init failure
    paths.
 
  - Avoid trapping CTR_EL0 on systems with Enhanced Virtualization Traps
    (FEAT_EVT), as it is a register commonly read from userspace.
 
  - Erratum workaround for the upcoming AmpereOne part, which has broken
    hardware A/D state management.
 
 As a consequence of the hVHE series reworking the arm64 software
 features framework, the for-next/module-alloc branch from the arm64 tree
 comes along for the ride.
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Merge tag 'kvmarm-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for 6.5

 - Eager page splitting optimization for dirty logging, optionally
   allowing for a VM to avoid the cost of block splitting in the stage-2
   fault path.

 - Arm FF-A proxy for pKVM, allowing a pKVM host to safely interact with
   services that live in the Secure world. pKVM intervenes on FF-A calls
   to guarantee the host doesn't misuse memory donated to the hyp or a
   pKVM guest.

 - Support for running the split hypervisor with VHE enabled, known as
   'hVHE' mode. This is extremely useful for testing the split
   hypervisor on VHE-only systems, and paves the way for new use cases
   that depend on having two TTBRs available at EL2.

 - Generalized framework for configurable ID registers from userspace.
   KVM/arm64 currently prevents arbitrary CPU feature set configuration
   from userspace, but the intent is to relax this limitation and allow
   userspace to select a feature set consistent with the CPU.

 - Enable the use of Branch Target Identification (FEAT_BTI) in the
   hypervisor.

 - Use a separate set of pointer authentication keys for the hypervisor
   when running in protected mode, as the host is untrusted at runtime.

 - Ensure timer IRQs are consistently released in the init failure
   paths.

 - Avoid trapping CTR_EL0 on systems with Enhanced Virtualization Traps
   (FEAT_EVT), as it is a register commonly read from userspace.

 - Erratum workaround for the upcoming AmpereOne part, which has broken
   hardware A/D state management.

As a consequence of the hVHE series reworking the arm64 software
features framework, the for-next/module-alloc branch from the arm64 tree
comes along for the ride.
2023-07-01 07:04:29 -04:00
Linus Torvalds
2605e80d34 arm64 updates for 6.5:
- Support for the Armv8.9 Permission Indirection Extensions. While this
   feature doesn't add new functionality, it enables future support for
   Guarded Control Stacks (GCS) and Permission Overlays.
 
 - User-space support for the Armv8.8 memcpy/memset instructions.
 
 - arm64 perf: support the HiSilicon SoC uncore PMU, Arm CMN sysfs
   identifier, support for the NXP i.MX9 SoC DDRC PMU, fixes and
   cleanups.
 
 - Removal of superfluous ISBs on context switch (following retrospective
   architecture tightening).
 
 - Decode the ISS2 register during faults for additional information to
   help with debugging.
 
 - KPTI clean-up/simplification of the trampoline exit code.
 
 - Addressing several -Wmissing-prototype warnings.
 
 - Kselftest improvements for signal handling and ptrace.
 
 - Fix TPIDR2_EL0 restoring on sigreturn
 
 - Clean-up, robustness improvements of the module allocation code.
 
 - More sysreg conversions to the automatic register/bitfields
   generation.
 
 - CPU capabilities handling cleanup.
 
 - Arm documentation updates: ACPI, ptdump.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "Notable features are user-space support for the memcpy/memset
  instructions and the permission indirection extension.

   - Support for the Armv8.9 Permission Indirection Extensions. While
     this feature doesn't add new functionality, it enables future
     support for Guarded Control Stacks (GCS) and Permission Overlays

   - User-space support for the Armv8.8 memcpy/memset instructions

   - arm64 perf: support the HiSilicon SoC uncore PMU, Arm CMN sysfs
     identifier, support for the NXP i.MX9 SoC DDRC PMU, fixes and
     cleanups

   - Removal of superfluous ISBs on context switch (following
     retrospective architecture tightening)

   - Decode the ISS2 register during faults for additional information
     to help with debugging

   - KPTI clean-up/simplification of the trampoline exit code

   - Addressing several -Wmissing-prototype warnings

   - Kselftest improvements for signal handling and ptrace

   - Fix TPIDR2_EL0 restoring on sigreturn

   - Clean-up, robustness improvements of the module allocation code

   - More sysreg conversions to the automatic register/bitfields
     generation

   - CPU capabilities handling cleanup

   - Arm documentation updates: ACPI, ptdump"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (124 commits)
  kselftest/arm64: Add a test case for TPIDR2 restore
  arm64/signal: Restore TPIDR2 register rather than memory state
  arm64: alternatives: make clean_dcache_range_nopatch() noinstr-safe
  Documentation/arm64: Add ptdump documentation
  arm64: hibernate: remove WARN_ON in save_processor_state
  kselftest/arm64: Log signal code and address for unexpected signals
  docs: perf: Fix warning from 'make htmldocs' in hisi-pmu.rst
  arm64/fpsimd: Exit streaming mode when flushing tasks
  docs: perf: Add new description for HiSilicon UC PMU
  drivers/perf: hisi: Add support for HiSilicon UC PMU driver
  drivers/perf: hisi: Add support for HiSilicon H60PA and PAv3 PMU driver
  perf: arm_cspmu: Add missing MODULE_DEVICE_TABLE
  perf/arm-cmn: Add sysfs identifier
  perf/arm-cmn: Revamp model detection
  perf/arm_dmc620: Add cpumask
  arm64: mm: fix VA-range sanity check
  arm64/mm: remove now-superfluous ISBs from TTBR writes
  Documentation/arm64: Update ACPI tables from BBR
  Documentation/arm64: Update references in arm-acpi
  Documentation/arm64: Update ARM and arch reference
  ...
2023-06-26 17:11:53 -07:00
Catalin Marinas
abc17128c8 Merge branch 'for-next/feat_s1pie' into for-next/core
* for-next/feat_s1pie:
  : Support for the Armv8.9 Permission Indirection Extensions (stage 1 only)
  KVM: selftests: get-reg-list: add Permission Indirection registers
  KVM: selftests: get-reg-list: support ID register features
  arm64: Document boot requirements for PIE
  arm64: transfer permission indirection settings to EL2
  arm64: enable Permission Indirection Extension (PIE)
  arm64: add encodings of PIRx_ELx registers
  arm64: disable EL2 traps for PIE
  arm64: reorganise PAGE_/PROT_ macros
  arm64: add PTE_WRITE to PROT_SECT_NORMAL
  arm64: add PTE_UXN/PTE_WRITE to SWAPPER_*_FLAGS
  KVM: arm64: expose ID_AA64MMFR3_EL1 to guests
  KVM: arm64: Save/restore PIE registers
  KVM: arm64: Save/restore TCR2_EL1
  arm64: cpufeature: add Permission Indirection Extension cpucap
  arm64: cpufeature: add TCR2 cpucap
  arm64: cpufeature: add system register ID_AA64MMFR3
  arm64/sysreg: add PIR*_ELx registers
  arm64/sysreg: update HCRX_EL2 register
  arm64/sysreg: add system registers TCR2_ELx
  arm64/sysreg: Add ID register ID_AA64MMFR3
2023-06-23 18:34:16 +01:00
Oliver Upton
89a734b54c Merge branch kvm-arm64/configurable-id-regs into kvmarm/next
* kvm-arm64/configurable-id-regs:
  : Configurable ID register infrastructure, courtesy of Jing Zhang
  :
  : Create generalized infrastructure for allowing userspace to select the
  : supported feature set for a VM, so long as the feature set is a subset
  : of what hardware + KVM allows. This does not add any new features that
  : are user-configurable, and instead focuses on the necessary refactoring
  : to enable future work.
  :
  : As a consequence of the series, feature asymmetry is now deliberately
  : disallowed for KVM. It is unlikely that VMMs ever configured VMs with
  : asymmetry, nor does it align with the kernel's overall stance that
  : features must be uniform across all cores in the system.
  :
  : Furthermore, KVM incorrectly advertised an IMP_DEF PMU to guests for
  : some time. Migrations from affected kernels was supported by explicitly
  : allowing such an ID register value from userspace, and forwarding that
  : along to the guest. KVM now allows an IMP_DEF PMU version to be restored
  : through the ID register interface, but reinterprets the user value as
  : not implemented (0).
  KVM: arm64: Rip out the vestiges of the 'old' ID register scheme
  KVM: arm64: Handle ID register reads using the VM-wide values
  KVM: arm64: Use generic sanitisation for ID_AA64PFR0_EL1
  KVM: arm64: Use generic sanitisation for ID_(AA64)DFR0_EL1
  KVM: arm64: Use arm64_ftr_bits to sanitise ID register writes
  KVM: arm64: Save ID registers' sanitized value per guest
  KVM: arm64: Reuse fields of sys_reg_desc for idreg
  KVM: arm64: Rewrite IMPDEF PMU version as NI
  KVM: arm64: Make vCPU feature flags consistent VM-wide
  KVM: arm64: Relax invariance of KVM_ARM_VCPU_POWER_OFF
  KVM: arm64: Separate out feature sanitisation and initialisation

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-15 13:05:11 +00:00
Oliver Upton
1a08f4927a Merge branch kvm-arm64/ffa-proxy into kvmarm/next
* kvm-arm64/ffa-proxy:
  : pKVM FF-A Proxy, courtesy Will Deacon and Andrew Walbran
  :
  : From the cover letter:
  :
  : pKVM's primary goal is to protect guest pages from a compromised host by
  : enforcing access control restrictions using stage-2 page-tables. Sadly,
  : this cannot prevent TrustZone from accessing non-secure memory, and a
  : compromised host could, for example, perform a 'confused deputy' attack
  : by asking TrustZone to use pages that have been donated to protected
  : guests. This would effectively allow the host to have TrustZone
  : exfiltrate guest secrets on its behalf, hence breaking the isolation
  : that pKVM intends to provide.
  :
  : This series addresses this problem by providing pKVM with the ability to
  : monitor SMCs following the Arm FF-A protocol. FF-A provides (among other
  : things) a set of memory management APIs allowing the Normal World to
  : share, donate or lend pages with Secure. By monitoring these SMCs, pKVM
  : can ensure that the pages that are shared, lent or donated to Secure by
  : the host kernel are only pages that it owns.
  KVM: arm64: pkvm: Add support for fragmented FF-A descriptors
  KVM: arm64: Handle FFA_FEATURES call from the host
  KVM: arm64: Handle FFA_MEM_LEND calls from the host
  KVM: arm64: Handle FFA_MEM_RECLAIM calls from the host
  KVM: arm64: Handle FFA_MEM_SHARE calls from the host
  KVM: arm64: Add FF-A helpers to share/unshare memory with secure world
  KVM: arm64: Handle FFA_RXTX_MAP and FFA_RXTX_UNMAP calls from the host
  KVM: arm64: Allocate pages for hypervisor FF-A mailboxes
  KVM: arm64: Probe FF-A version and host/hyp partition ID during init
  KVM: arm64: Block unsafe FF-A calls from the host

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-15 13:02:37 +00:00
Oliver Upton
686672407e KVM: arm64: Rip out the vestiges of the 'old' ID register scheme
There's no longer a need for the baggage of the old scheme for handling
configurable ID register fields. Rip it all out in favor of the
generalized infrastructure.

Link: https://lore.kernel.org/r/20230609190054.1542113-12-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-15 12:55:35 +00:00
Jing Zhang
4733414690 KVM: arm64: Save ID registers' sanitized value per guest
Initialize the default ID register values upon the first call to
KVM_ARM_VCPU_INIT. The vCPU feature flags are finalized at that point,
so it is possible to determine the maximum feature set supported by a
particular VM configuration. Do nothing with these values for now, as we
need to rework the plumbing of what's already writable to be compatible
with the generic infrastructure.

Co-developed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Link: https://lore.kernel.org/r/20230609190054.1542113-7-oliver.upton@linux.dev
[Oliver: Hoist everything into KVM_ARM_VCPU_INIT time, so the features
 are final]
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-15 12:55:08 +00:00
Oliver Upton
f90f9360c3 KVM: arm64: Rewrite IMPDEF PMU version as NI
KVM allows userspace to write an IMPDEF PMU version to the corresponding
32bit and 64bit ID register fields for the sake of backwards
compatibility with kernels that lacked commit 3d0dba5764 ("KVM: arm64:
PMU: Move the ID_AA64DFR0_EL1.PMUver limit to VM creation"). Plumbing
that IMPDEF PMU version through to the gues is getting in the way of
progress, and really doesn't any sense in the first place.

Bite the bullet and reinterpret the IMPDEF PMU version as NI (0) for
userspace writes. Additionally, spill the dirty details into a comment.

Link: https://lore.kernel.org/r/20230609190054.1542113-5-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-12 23:08:33 +00:00
Oliver Upton
2251e9ff15 KVM: arm64: Make vCPU feature flags consistent VM-wide
To date KVM has allowed userspace to construct asymmetric VMs where
particular features may only be supported on a subset of vCPUs. This
wasn't really the intened usage pattern, and it is a total pain in the
ass to keep working in the kernel. What's more, this is at odds with CPU
features in host userspace, where asymmetric features are largely hidden
or disabled.

It's time to put an end to the whole game. Require all vCPUs in the VM
to have the same feature set, rejecting deviants in the
KVM_ARM_VCPU_INIT ioctl. Preserve some of the vestiges of per-vCPU
feature flags in case we need to reinstate the old behavior for some
limited configurations. Yes, this is a sign of cowardice around a
user-visibile change.

Hoist all of the 32-bit limitations into kvm_vcpu_init_check_features()
to avoid nested attempts to acquire the config_lock, which won't end
well.

Link: https://lore.kernel.org/r/20230609190054.1542113-4-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-12 23:08:33 +00:00
Oliver Upton
a7a2c72ae0 KVM: arm64: Separate out feature sanitisation and initialisation
kvm_vcpu_set_target() iteratively sanitises and copies feature flags in
one go. This is rather odd, especially considering the fact that bitmap
accessors can do the heavy lifting. A subsequent change will make vCPU
features VM-wide, and fitting that into the present implementation is
just a chore.

Rework the whole thing to use bitmap accessors to sanitise and copy
flags.

Link: https://lore.kernel.org/r/20230609190054.1542113-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-12 23:08:33 +00:00
Mark Brown
187de7c2aa arm64/sysreg: Standardise naming of bitfield constants in OSL[AS]R_EL1
Our standard scheme for naming the constants for bitfields in system
registers includes _ELx in the name but not the SYS_, update the
constants for OSL[AS]R_EL1 to follow this convention.

Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20230419-arm64-syreg-gen-v2-3-4c6add1f6257@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-06-06 17:43:08 +01:00
Joey Gouly
86f9de9db1 KVM: arm64: Save/restore PIE registers
Define the new system registers that PIE introduces and context switch them.
The PIE feature is still hidden from the ID register, and not exposed to a VM.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Zenghui Yu <yuzenghui@huawei.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230606145859.697944-10-joey.gouly@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-06-06 16:52:40 +01:00
Joey Gouly
fbff560682 KVM: arm64: Save/restore TCR2_EL1
Define the new system register TCR2_EL1 and context switch it.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Zenghui Yu <yuzenghui@huawei.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230606145859.697944-9-joey.gouly@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2023-06-06 16:52:40 +01:00
Reiji Watanabe
0c2f9acf6a KVM: arm64: PMU: Don't overwrite PMUSERENR with vcpu loaded
Currently, with VHE, KVM sets ER, CR, SW and EN bits of
PMUSERENR_EL0 to 1 on vcpu_load(), and saves and restores
the register value for the host on vcpu_load() and vcpu_put().
If the value of those bits are cleared on a pCPU with a vCPU
loaded (armv8pmu_start() would do that when PMU counters are
programmed for the guest), PMU access from the guest EL0 might
be trapped to the guest EL1 directly regardless of the current
PMUSERENR_EL0 value of the vCPU.

Fix this by not letting armv8pmu_start() overwrite PMUSERENR_EL0
on the pCPU where PMUSERENR_EL0 for the guest is loaded, and
instead updating the saved shadow register value for the host
so that the value can be restored on vcpu_put() later.
While vcpu_{put,load}() are manipulating PMUSERENR_EL0, disable
IRQs to prevent a race condition between these processes and IPIs
that attempt to update PMUSERENR_EL0 for the host EL0.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Suggested-by: Marc Zyngier <maz@kernel.org>
Fixes: 83a7a4d643 ("arm64: perf: Enable PMU counter userspace access for perf event")
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230603025035.3781797-3-reijiw@google.com
2023-06-04 17:19:36 +01:00
Will Deacon
12bdce4f41 KVM: arm64: Probe FF-A version and host/hyp partition ID during init
Probe FF-A during pKVM initialisation so that we can detect any
inconsistencies in the version or partition ID early on.

Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230523101828.7328-3-will@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-01 21:34:50 +00:00
Ricardo Koller
2f440b72e8 KVM: arm64: Add KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE
Add a capability for userspace to specify the eager split chunk size.
The chunk size specifies how many pages to break at a time, using a
single allocation. Bigger the chunk size, more pages need to be
allocated ahead of time.

Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/20230426172330.1439644-6-ricarkol@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-05-16 17:39:18 +00:00
Linus Torvalds
c8c655c34e s390:
* More phys_to_virt conversions
 
 * Improvement of AP management for VSIE (nested virtualization)
 
 ARM64:
 
 * Numerous fixes for the pathological lock inversion issue that
   plagued KVM/arm64 since... forever.
 
 * New framework allowing SMCCC-compliant hypercalls to be forwarded
   to userspace, hopefully paving the way for some more features
   being moved to VMMs rather than be implemented in the kernel.
 
 * Large rework of the timer code to allow a VM-wide offset to be
   applied to both virtual and physical counters as well as a
   per-timer, per-vcpu offset that complements the global one.
   This last part allows the NV timer code to be implemented on
   top.
 
 * A small set of fixes to make sure that we don't change anything
   affecting the EL1&0 translation regime just after having having
   taken an exception to EL2 until we have executed a DSB. This
   ensures that speculative walks started in EL1&0 have completed.
 
 * The usual selftest fixes and improvements.
 
 KVM x86 changes for 6.4:
 
 * Optimize CR0.WP toggling by avoiding an MMU reload when TDP is enabled,
   and by giving the guest control of CR0.WP when EPT is enabled on VMX
   (VMX-only because SVM doesn't support per-bit controls)
 
 * Add CR0/CR4 helpers to query single bits, and clean up related code
   where KVM was interpreting kvm_read_cr4_bits()'s "unsigned long" return
   as a bool
 
 * Move AMD_PSFD to cpufeatures.h and purge KVM's definition
 
 * Avoid unnecessary writes+flushes when the guest is only adding new PTEs
 
 * Overhaul .sync_page() and .invlpg() to utilize .sync_page()'s optimizations
   when emulating invalidations
 
 * Clean up the range-based flushing APIs
 
 * Revamp the TDP MMU's reaping of Accessed/Dirty bits to clear a single
   A/D bit using a LOCK AND instead of XCHG, and skip all of the "handle
   changed SPTE" overhead associated with writing the entire entry
 
 * Track the number of "tail" entries in a pte_list_desc to avoid having
   to walk (potentially) all descriptors during insertion and deletion,
   which gets quite expensive if the guest is spamming fork()
 
 * Disallow virtualizing legacy LBRs if architectural LBRs are available,
   the two are mutually exclusive in hardware
 
 * Disallow writes to immutable feature MSRs (notably PERF_CAPABILITIES)
   after KVM_RUN, similar to CPUID features
 
 * Overhaul the vmx_pmu_caps selftest to better validate PERF_CAPABILITIES
 
 * Apply PMU filters to emulated events and add test coverage to the
   pmu_event_filter selftest
 
 x86 AMD:
 
 * Add support for virtual NMIs
 
 * Fixes for edge cases related to virtual interrupts
 
 x86 Intel:
 
 * Don't advertise XTILE_CFG in KVM_GET_SUPPORTED_CPUID if XTILE_DATA is
   not being reported due to userspace not opting in via prctl()
 
 * Fix a bug in emulation of ENCLS in compatibility mode
 
 * Allow emulation of NOP and PAUSE for L2
 
 * AMX selftests improvements
 
 * Misc cleanups
 
 MIPS:
 
 * Constify MIPS's internal callbacks (a leftover from the hardware enabling
   rework that landed in 6.3)
 
 Generic:
 
 * Drop unnecessary casts from "void *" throughout kvm_main.c
 
 * Tweak the layout of "struct kvm_mmu_memory_cache" to shrink the struct
   size by 8 bytes on 64-bit kernels by utilizing a padding hole
 
 Documentation:
 
 * Fix goof introduced by the conversion to rST
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "s390:

   - More phys_to_virt conversions

   - Improvement of AP management for VSIE (nested virtualization)

  ARM64:

   - Numerous fixes for the pathological lock inversion issue that
     plagued KVM/arm64 since... forever.

   - New framework allowing SMCCC-compliant hypercalls to be forwarded
     to userspace, hopefully paving the way for some more features being
     moved to VMMs rather than be implemented in the kernel.

   - Large rework of the timer code to allow a VM-wide offset to be
     applied to both virtual and physical counters as well as a
     per-timer, per-vcpu offset that complements the global one. This
     last part allows the NV timer code to be implemented on top.

   - A small set of fixes to make sure that we don't change anything
     affecting the EL1&0 translation regime just after having having
     taken an exception to EL2 until we have executed a DSB. This
     ensures that speculative walks started in EL1&0 have completed.

   - The usual selftest fixes and improvements.

  x86:

   - Optimize CR0.WP toggling by avoiding an MMU reload when TDP is
     enabled, and by giving the guest control of CR0.WP when EPT is
     enabled on VMX (VMX-only because SVM doesn't support per-bit
     controls)

   - Add CR0/CR4 helpers to query single bits, and clean up related code
     where KVM was interpreting kvm_read_cr4_bits()'s "unsigned long"
     return as a bool

   - Move AMD_PSFD to cpufeatures.h and purge KVM's definition

   - Avoid unnecessary writes+flushes when the guest is only adding new
     PTEs

   - Overhaul .sync_page() and .invlpg() to utilize .sync_page()'s
     optimizations when emulating invalidations

   - Clean up the range-based flushing APIs

   - Revamp the TDP MMU's reaping of Accessed/Dirty bits to clear a
     single A/D bit using a LOCK AND instead of XCHG, and skip all of
     the "handle changed SPTE" overhead associated with writing the
     entire entry

   - Track the number of "tail" entries in a pte_list_desc to avoid
     having to walk (potentially) all descriptors during insertion and
     deletion, which gets quite expensive if the guest is spamming
     fork()

   - Disallow virtualizing legacy LBRs if architectural LBRs are
     available, the two are mutually exclusive in hardware

   - Disallow writes to immutable feature MSRs (notably
     PERF_CAPABILITIES) after KVM_RUN, similar to CPUID features

   - Overhaul the vmx_pmu_caps selftest to better validate
     PERF_CAPABILITIES

   - Apply PMU filters to emulated events and add test coverage to the
     pmu_event_filter selftest

   - AMD SVM:
       - Add support for virtual NMIs
       - Fixes for edge cases related to virtual interrupts

   - Intel AMX:
       - Don't advertise XTILE_CFG in KVM_GET_SUPPORTED_CPUID if
         XTILE_DATA is not being reported due to userspace not opting in
         via prctl()
       - Fix a bug in emulation of ENCLS in compatibility mode
       - Allow emulation of NOP and PAUSE for L2
       - AMX selftests improvements
       - Misc cleanups

  MIPS:

   - Constify MIPS's internal callbacks (a leftover from the hardware
     enabling rework that landed in 6.3)

  Generic:

   - Drop unnecessary casts from "void *" throughout kvm_main.c

   - Tweak the layout of "struct kvm_mmu_memory_cache" to shrink the
     struct size by 8 bytes on 64-bit kernels by utilizing a padding
     hole

  Documentation:

   - Fix goof introduced by the conversion to rST"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (211 commits)
  KVM: s390: pci: fix virtual-physical confusion on module unload/load
  KVM: s390: vsie: clarifications on setting the APCB
  KVM: s390: interrupt: fix virtual-physical confusion for next alert GISA
  KVM: arm64: Have kvm_psci_vcpu_on() use WRITE_ONCE() to update mp_state
  KVM: arm64: Acquire mp_state_lock in kvm_arch_vcpu_ioctl_vcpu_init()
  KVM: selftests: Test the PMU event "Instructions retired"
  KVM: selftests: Copy full counter values from guest in PMU event filter test
  KVM: selftests: Use error codes to signal errors in PMU event filter test
  KVM: selftests: Print detailed info in PMU event filter asserts
  KVM: selftests: Add helpers for PMC asserts in PMU event filter test
  KVM: selftests: Add a common helper for the PMU event filter guest code
  KVM: selftests: Fix spelling mistake "perrmited" -> "permitted"
  KVM: arm64: vhe: Drop extra isb() on guest exit
  KVM: arm64: vhe: Synchronise with page table walker on MMU update
  KVM: arm64: pkvm: Document the side effects of kvm_flush_dcache_to_poc()
  KVM: arm64: nvhe: Synchronise with page table walker on TLBI
  KVM: arm64: Handle 32bit CNTPCTSS traps
  KVM: arm64: nvhe: Synchronise with page table walker on vcpu run
  KVM: arm64: vgic: Don't acquire its_lock before config_lock
  KVM: selftests: Add test to verify KVM's supported XCR0
  ...
2023-05-01 12:06:20 -07:00
Paolo Bonzini
4f382a79a6 KVM/arm64 updates for 6.4
- Numerous fixes for the pathological lock inversion issue that
   plagued KVM/arm64 since... forever.
 
 - New framework allowing SMCCC-compliant hypercalls to be forwarded
   to userspace, hopefully paving the way for some more features
   being moved to VMMs rather than be implemented in the kernel.
 
 - Large rework of the timer code to allow a VM-wide offset to be
   applied to both virtual and physical counters as well as a
   per-timer, per-vcpu offset that complements the global one.
   This last part allows the NV timer code to be implemented on
   top.
 
 - A small set of fixes to make sure that we don't change anything
   affecting the EL1&0 translation regime just after having having
   taken an exception to EL2 until we have executed a DSB. This
   ensures that speculative walks started in EL1&0 have completed.
 
 - The usual selftest fixes and improvements.
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Merge tag 'kvmarm-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for 6.4

- Numerous fixes for the pathological lock inversion issue that
  plagued KVM/arm64 since... forever.

- New framework allowing SMCCC-compliant hypercalls to be forwarded
  to userspace, hopefully paving the way for some more features
  being moved to VMMs rather than be implemented in the kernel.

- Large rework of the timer code to allow a VM-wide offset to be
  applied to both virtual and physical counters as well as a
  per-timer, per-vcpu offset that complements the global one.
  This last part allows the NV timer code to be implemented on
  top.

- A small set of fixes to make sure that we don't change anything
  affecting the EL1&0 translation regime just after having having
  taken an exception to EL2 until we have executed a DSB. This
  ensures that speculative walks started in EL1&0 have completed.

- The usual selftest fixes and improvements.
2023-04-26 15:46:52 -04:00
Marc Zyngier
6dcf7316e0 Merge branch kvm-arm64/smccc-filtering into kvmarm-master/next
* kvm-arm64/smccc-filtering:
  : .
  : SMCCC call filtering and forwarding to userspace, courtesy of
  : Oliver Upton. From the cover letter:
  :
  : "The Arm SMCCC is rather prescriptive in regards to the allocation of
  : SMCCC function ID ranges. Many of the hypercall ranges have an
  : associated specification from Arm (FF-A, PSCI, SDEI, etc.) with some
  : room for vendor-specific implementations.
  :
  : The ever-expanding SMCCC surface leaves a lot of work within KVM for
  : providing new features. Furthermore, KVM implements its own
  : vendor-specific ABI, with little room for other implementations (like
  : Hyper-V, for example). Rather than cramming it all into the kernel we
  : should provide a way for userspace to handle hypercalls."
  : .
  KVM: selftests: Fix spelling mistake "KVM_HYPERCAL_EXIT_SMC" -> "KVM_HYPERCALL_EXIT_SMC"
  KVM: arm64: Test that SMC64 arch calls are reserved
  KVM: arm64: Prevent userspace from handling SMC64 arch range
  KVM: arm64: Expose SMC/HVC width to userspace
  KVM: selftests: Add test for SMCCC filter
  KVM: selftests: Add a helper for SMCCC calls with SMC instruction
  KVM: arm64: Let errors from SMCCC emulation to reach userspace
  KVM: arm64: Return NOT_SUPPORTED to guest for unknown PSCI version
  KVM: arm64: Introduce support for userspace SMCCC filtering
  KVM: arm64: Add support for KVM_EXIT_HYPERCALL
  KVM: arm64: Use a maple tree to represent the SMCCC filter
  KVM: arm64: Refactor hvc filtering to support different actions
  KVM: arm64: Start handling SMCs from EL1
  KVM: arm64: Rename SMC/HVC call handler to reflect reality
  KVM: arm64: Add vm fd device attribute accessors
  KVM: arm64: Add a helper to check if a VM has ran once
  KVM: x86: Redefine 'longmode' as a flag for KVM_EXIT_HYPERCALL

Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-04-21 09:44:32 +01:00
Marc Zyngier
b22498c484 Merge branch kvm-arm64/timer-vm-offsets into kvmarm-master/next
* kvm-arm64/timer-vm-offsets: (21 commits)
  : .
  : This series aims at satisfying multiple goals:
  :
  : - allow a VMM to atomically restore a timer offset for a whole VM
  :   instead of updating the offset each time a vcpu get its counter
  :   written
  :
  : - allow a VMM to save/restore the physical timer context, something
  :   that we cannot do at the moment due to the lack of offsetting
  :
  : - provide a framework that is suitable for NV support, where we get
  :   both global and per timer, per vcpu offsetting, and manage
  :   interrupts in a less braindead way.
  :
  : Conflict resolution involves using the new per-vcpu config lock instead
  : of the home-grown timer lock.
  : .
  KVM: arm64: Handle 32bit CNTPCTSS traps
  KVM: arm64: selftests: Augment existing timer test to handle variable offset
  KVM: arm64: selftests: Deal with spurious timer interrupts
  KVM: arm64: selftests: Add physical timer registers to the sysreg list
  KVM: arm64: nv: timers: Support hyp timer emulation
  KVM: arm64: nv: timers: Add a per-timer, per-vcpu offset
  KVM: arm64: Document KVM_ARM_SET_CNT_OFFSETS and co
  KVM: arm64: timers: Abstract the number of valid timers per vcpu
  KVM: arm64: timers: Fast-track CNTPCT_EL0 trap handling
  KVM: arm64: Elide kern_hyp_va() in VHE-specific parts of the hypervisor
  KVM: arm64: timers: Move the timer IRQs into arch_timer_vm_data
  KVM: arm64: timers: Abstract per-timer IRQ access
  KVM: arm64: timers: Rationalise per-vcpu timer init
  KVM: arm64: timers: Allow save/restoring of the physical timer
  KVM: arm64: timers: Allow userspace to set the global counter offset
  KVM: arm64: Expose {un,}lock_all_vcpus() to the rest of KVM
  KVM: arm64: timers: Allow physical offset without CNTPOFF_EL2
  KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timer
  arm64: Add HAS_ECV_CNTPOFF capability
  arm64: Add CNTPOFF_EL2 register definition
  ...

Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-04-21 09:36:40 +01:00
Marc Zyngier
35dcb3ac66 KVM: arm64: Make vcpu flag updates non-preemptible
Per-vcpu flags are updated using a non-atomic RMW operation.
Which means it is possible to get preempted between the read and
write operations.

Another interesting thing to note is that preemption also updates
flags, as we have some flag manipulation in both the load and put
operations.

It is thus possible to lose information communicated by either
load or put, as the preempted flag update will overwrite the flags
when the thread is resumed. This is specially critical if either
load or put has stored information which depends on the physical
CPU the vcpu runs on.

This results in really elusive bugs, and kudos must be given to
Mostafa for the long hours of debugging, and finally spotting
the problem.

Fix it by disabling preemption during the RMW operation, which
ensures that the state stays consistent. Also upgrade vcpu_get_flag
path to use READ_ONCE() to make sure the field is always atomically
accessed.

Fixes: e87abb73e5 ("KVM: arm64: Add helpers to manipulate vcpu flags among a set")
Reported-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230418125737.2327972-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-04-18 17:08:09 +00:00
Oliver Upton
fb88707dd3 KVM: arm64: Use a maple tree to represent the SMCCC filter
Maple tree is an efficient B-tree implementation that is intended for
storing non-overlapping intervals. Such a data structure is a good fit
for the SMCCC filter as it is desirable to sparsely allocate the 32 bit
function ID space.

To that end, add a maple tree to kvm_arch and correctly init/teardown
along with the VM. Wire in a test against the hypercall filter for HVCs
which does nothing until the controls are exposed to userspace.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230404154050.2270077-8-oliver.upton@linux.dev
2023-04-05 12:07:41 +01:00
Oliver Upton
de40bb8abb KVM: arm64: Add a helper to check if a VM has ran once
The test_bit(...) pattern is quite a lot of keystrokes. Replace
existing callsites with a helper.

No functional change intended.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230404154050.2270077-3-oliver.upton@linux.dev
2023-04-05 12:07:41 +01:00
Marc Zyngier
81dc9504a7 KVM: arm64: nv: timers: Support hyp timer emulation
Emulating EL2 also means emulating the EL2 timers. To do so, we expand
our timer framework to deal with at most 4 timers. At any given time,
two timers are using the HW timers, and the two others are purely
emulated.

The role of deciding which is which at any given time is left to a
mapping function which is called every time we need to make such a
decision.

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Co-developed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-18-maz@kernel.org
2023-03-30 19:01:10 +01:00
Marc Zyngier
8a5eb2d210 KVM: arm64: timers: Move the timer IRQs into arch_timer_vm_data
Having the timer IRQs duplicated into each vcpu isn't great, and
becomes absolutely awful with NV. So let's move these into
the per-VM arch_timer_vm_data structure.

This simplifies a lot of code, but requires us to introduce a
mutex so that we can reason about userspace trying to change
an interrupt number while another vcpu is running, something
that wasn't really well handled so far.

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-12-maz@kernel.org
2023-03-30 19:01:10 +01:00
Marc Zyngier
30ec7997d1 KVM: arm64: timers: Allow userspace to set the global counter offset
And this is the moment you have all been waiting for: setting the
counter offset from userspace.

We expose a brand new capability that reports the ability to set
the offset for both the virtual and physical sides.

In keeping with the architecture, the offset is expressed as
a delta that is substracted from the physical counter value.

Once this new API is used, there is no going back, and the counters
cannot be written to to set the offsets implicitly (the writes
are instead ignored).

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-8-maz@kernel.org
2023-03-30 19:01:10 +01:00
Marc Zyngier
96906a9150 KVM: arm64: Expose {un,}lock_all_vcpus() to the rest of KVM
Being able to lock/unlock all vcpus in one go is a feature that
only the vgic has enjoyed so far. Let's be brave and expose it
to the world.

Reviewed-by: Colton Lewis <coltonlewis@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230330174800.2677007-7-maz@kernel.org
2023-03-30 19:01:09 +01:00
Oliver Upton
c43120afb5 KVM: arm64: Avoid lock inversion when setting the VM register width
kvm->lock must be taken outside of the vcpu->mutex. Of course, the
locking documentation for KVM makes this abundantly clear. Nonetheless,
the locking order in KVM/arm64 has been wrong for quite a while; we
acquire the kvm->lock while holding the vcpu->mutex all over the shop.

All was seemingly fine until commit 42a90008f8 ("KVM: Ensure lockdep
knows about kvm->lock vs. vcpu->mutex ordering rule") caught us with our
pants down, leading to lockdep barfing:

 ======================================================
 WARNING: possible circular locking dependency detected
 6.2.0-rc7+ #19 Not tainted
 ------------------------------------------------------
 qemu-system-aar/859 is trying to acquire lock:
 ffff5aa69269eba0 (&host_kvm->lock){+.+.}-{3:3}, at: kvm_reset_vcpu+0x34/0x274

 but task is already holding lock:
 ffff5aa68768c0b8 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x8c/0xba0

 which lock already depends on the new lock.

Add a dedicated lock to serialize writes to VM-scoped configuration from
the context of a vCPU. Protect the register width flags with the new
lock, thus avoiding the need to grab the kvm->lock while holding
vcpu->mutex in kvm_reset_vcpu().

Cc: stable@vger.kernel.org
Reported-by: Jeremy Linton <jeremy.linton@arm.com>
Link: https://lore.kernel.org/kvmarm/f6452cdd-65ff-34b8-bab0-5c06416da5f6@arm.com/
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230327164747.2466958-3-oliver.upton@linux.dev
2023-03-29 14:08:31 +01:00
Oliver Upton
0acc7239c2 KVM: arm64: Avoid vcpu->mutex v. kvm->lock inversion in CPU_ON
KVM/arm64 had the lock ordering backwards on vcpu->mutex and kvm->lock
from the very beginning. One such example is the way vCPU resets are
handled: the kvm->lock is acquired while handling a guest CPU_ON PSCI
call.

Add a dedicated lock to serialize writes to kvm_vcpu_arch::{mp_state,
reset_state}. Promote all accessors of mp_state to {READ,WRITE}_ONCE()
as readers do not acquire the mp_state_lock. While at it, plug yet
another race by taking the mp_state_lock in the KVM_SET_MP_STATE ioctl
handler.

As changes to MP state are now guarded with a dedicated lock, drop the
kvm->lock acquisition from the PSCI CPU_ON path. Similarly, move the
reader of reset_state outside of the kvm->lock and instead protect it
with the mp_state_lock. Note that writes to reset_state::reset have been
demoted to regular stores as both readers and writers acquire the
mp_state_lock.

While the kvm->lock inversion still exists in kvm_reset_vcpu(), at least
now PSCI CPU_ON no longer depends on it for serializing vCPU reset.

Cc: stable@vger.kernel.org
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230327164747.2466958-2-oliver.upton@linux.dev
2023-03-29 14:08:31 +01:00
Thomas Huth
2def950c63 KVM: arm64: Limit length in kvm_vm_ioctl_mte_copy_tags() to INT_MAX
In case of success, this function returns the amount of handled bytes.
However, this does not work for large values: The function is called
from kvm_arch_vm_ioctl() (which still returns a long), which in turn
is called from kvm_vm_ioctl() in virt/kvm/kvm_main.c. And that function
stores the return value in an "int r" variable. So the upper 32-bits
of the "long" return value are lost there.

KVM ioctl functions should only return "int" values, so let's limit
the amount of bytes that can be requested here to INT_MAX to avoid
the problem with the truncated return value. We can then also change
the return type of the function to "int" to make it clearer that it
is not possible to return a "long" here.

Fixes: f0376edb1d ("KVM: arm64: Add ioctl to fetch/store tags in a guest")
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Message-Id: <20230208140105.655814-5-thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-03-16 10:18:06 -04:00
Marc Zyngier
47053904e1 KVM: arm64: timers: Convert per-vcpu virtual offset to a global value
Having a per-vcpu virtual offset is a pain. It needs to be synchronized
on each update, and expands badly to a setup where different timers can
have different offsets, or have composite offsets (as with NV).

So let's start by replacing the use of the CNTVOFF_EL2 shadow register
(which we want to reclaim for NV anyway), and make the virtual timer
carry a pointer to a VM-wide offset.

This simplifies the code significantly. It also addresses two terrible bugs:

- The use of CNTVOFF_EL2 leads to some nice offset corruption
  when the sysreg gets reset, as reported by Joey.

- The kvm mutex is taken from a vcpu ioctl, which goes against
  the locking rules...

Reported-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230224173915.GA17407@e124191.cambridge.arm.com
Tested-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20230224191640.3396734-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-03-11 02:00:40 -08:00
Oliver Upton
0d3b2b4d23 Merge branch kvm-arm64/nv-prefix into kvmarm/next
* kvm-arm64/nv-prefix:
  : Preamble to NV support, courtesy of Marc Zyngier.
  :
  : This brings in a set of prerequisite patches for supporting nested
  : virtualization in KVM/arm64. Of course, there is a long way to go until
  : NV is actually enabled in KVM.
  :
  :  - Introduce cpucap / vCPU feature flag to pivot the NV code on
  :
  :  - Add support for EL2 vCPU register state
  :
  :  - Basic nested exception handling
  :
  :  - Hide unsupported features from the ID registers for NV-capable VMs
  KVM: arm64: nv: Use reg_to_encoding() to get sysreg ID
  KVM: arm64: nv: Only toggle cache for virtual EL2 when SCTLR_EL2 changes
  KVM: arm64: nv: Filter out unsupported features from ID regs
  KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2
  KVM: arm64: nv: Allow a sysreg to be hidden from userspace only
  KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor
  KVM: arm64: nv: Add accessors for SPSR_EL1, ELR_EL1 and VBAR_EL1 from virtual EL2
  KVM: arm64: nv: Handle SMCs taken from virtual EL2
  KVM: arm64: nv: Handle trapped ERET from virtual EL2
  KVM: arm64: nv: Inject HVC exceptions to the virtual EL2
  KVM: arm64: nv: Support virtual EL2 exceptions
  KVM: arm64: nv: Handle HCR_EL2.NV system register traps
  KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state
  KVM: arm64: nv: Add EL2 system registers to vcpu context
  KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x
  KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set
  KVM: arm64: nv: Introduce nested virtualization VCPU feature
  KVM: arm64: Use the S2 MMU context to iterate over S2 table
  arm64: Add ARM64_HAS_NESTED_VIRT cpufeature

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-13 23:33:41 +00:00
Oliver Upton
022d3f0800 Merge branch kvm-arm64/misc into kvmarm/next
* kvm-arm64/misc:
  : Miscellaneous updates
  :
  :  - Convert CPACR_EL1_TTA to the new, generated system register
  :    definitions.
  :
  :  - Serialize toggling CPACR_EL1.SMEN to avoid unexpected exceptions when
  :    accessing SVCR in the host.
  :
  :  - Avoid quiescing the guest if a vCPU accesses its own redistributor's
  :    SGIs/PPIs, eliminating the need to IPI. Largely an optimization for
  :    nested virtualization, as the L1 accesses the affected registers
  :    rather often.
  :
  :  - Conversion to kstrtobool()
  :
  :  - Common definition of INVALID_GPA across architectures
  :
  :  - Enable CONFIG_USERFAULTFD for CI runs of KVM selftests
  KVM: arm64: Fix non-kerneldoc comments
  KVM: selftests: Enable USERFAULTFD
  KVM: selftests: Remove redundant setbuf()
  arm64/sysreg: clean up some inconsistent indenting
  KVM: MMU: Make the definition of 'INVALID_GPA' common
  KVM: arm64: vgic-v3: Use kstrtobool() instead of strtobool()
  KVM: arm64: vgic-v3: Limit IPI-ing when accessing GICR_{C,S}ACTIVER0
  KVM: arm64: Synchronize SMEN on vcpu schedule out
  KVM: arm64: Kill CPACR_EL1_TTA definition

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-13 23:33:25 +00:00
Oliver Upton
e8789ab704 Merge branch kvm-arm64/virtual-cache-geometry into kvmarm/next
* kvm-arm64/virtual-cache-geometry:
  : Virtualized cache geometry for KVM guests, courtesy of Akihiko Odaki.
  :
  : KVM/arm64 has always exposed the host cache geometry directly to the
  : guest, even though non-secure software should never perform CMOs by
  : Set/Way. This was slightly wrong, as the cache geometry was derived from
  : the PE on which the vCPU thread was running and not a sanitized value.
  :
  : All together this leads to issues migrating VMs on heterogeneous
  : systems, as the cache geometry saved/restored could be inconsistent.
  :
  : KVM/arm64 now presents 1 level of cache with 1 set and 1 way. The cache
  : geometry is entirely controlled by userspace, such that migrations from
  : older kernels continue to work.
  KVM: arm64: Mark some VM-scoped allocations as __GFP_ACCOUNT
  KVM: arm64: Normalize cache configuration
  KVM: arm64: Mask FEAT_CCIDX
  KVM: arm64: Always set HCR_TID2
  arm64/cache: Move CLIDR macro definitions
  arm64/sysreg: Add CCSIDR2_EL1
  arm64/sysreg: Convert CCSIDR_EL1 to automatic generation
  arm64: Allow the definition of UNKNOWN system register fields

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-13 22:32:40 +00:00
Marc Zyngier
d9552fe133 KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor
We can no longer blindly copy the VCPU's PSTATE into SPSR_EL2 and return
to the guest and vice versa when taking an exception to the hypervisor,
because we emulate virtual EL2 in EL1 and therefore have to translate
the mode field from EL2 to EL1 and vice versa.

This requires keeping track of the state we enter the guest, for which
we transiently use a dedicated flag.

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230209175820.1939006-15-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-11 10:13:29 +00:00
Jintack Lim
47f3a2fc76 KVM: arm64: nv: Support virtual EL2 exceptions
Support injecting exceptions and performing exception returns to and
from virtual EL2.  This must be done entirely in software except when
taking an exception from vEL0 to vEL2 when the virtual HCR_EL2.{E2H,TGE}
== {1,1}  (a VHE guest hypervisor).

[maz: switch to common exception injection framework, illegal exeption
 return handling]

Reviewed-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>
Signed-off-by: Jintack Lim <jintack.lim@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230209175820.1939006-10-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-11 09:16:11 +00:00
Marc Zyngier
5305cc2c34 KVM: arm64: nv: Add EL2 system registers to vcpu context
Add the minimal set of EL2 system registers to the vcpu context.
Nothing uses them just yet.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230209175820.1939006-7-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-11 09:16:11 +00:00
Jintack Lim
675cabc899 arm64: Add ARM64_HAS_NESTED_VIRT cpufeature
Add a new ARM64_HAS_NESTED_VIRT feature to indicate that the
CPU has the ARMv8.3 nested virtualization capability, together
with the 'kvm-arm.mode=nested' command line option.

This will be used to support nested virtualization in KVM.

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jintack Lim <jintack.lim@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
[maz: moved the command-line option to kvm-arm.mode]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230209175820.1939006-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-11 09:16:11 +00:00
Akihiko Odaki
7af0c2534f KVM: arm64: Normalize cache configuration
Before this change, the cache configuration of the physical CPU was
exposed to vcpus. This is problematic because the cache configuration a
vcpu sees varies when it migrates between vcpus with different cache
configurations.

Fabricate cache configuration from the sanitized value, which holds the
CTR_EL0 value the userspace sees regardless of which physical CPU it
resides on.

CLIDR_EL1 and CCSIDR_EL1 are now writable from the userspace so that
the VMM can restore the values saved with the old kernel.

Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Link: https://lore.kernel.org/r/20230112023852.42012-8-akihiko.odaki@daynix.com
[ Oliver: Squash Marc's fix for CCSIDR_EL1.LineSize when set from userspace ]
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-01-21 18:09:23 +00:00
Yu Zhang
cecafc0a83 KVM: MMU: Make the definition of 'INVALID_GPA' common
KVM already has a 'GPA_INVALID' defined as (~(gpa_t)0) in kvm_types.h,
and it is used by ARM code. We do not need another definition of
'INVALID_GPA' for X86 specifically.

Instead of using the common 'GPA_INVALID' for X86, replace it with
'INVALID_GPA', and change the users of 'GPA_INVALID' so that the diff
can be smaller. Also because the name 'INVALID_GPA' tells the user we
are using an invalid GPA, while the name 'GPA_INVALID' is emphasizing
the GPA is an invalid one.

No functional change intended.

Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20230105130127.866171-1-yu.c.zhang@linux.intel.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-01-19 21:48:38 +00:00
Akihiko Odaki
8cc6dedaff KVM: arm64: Always set HCR_TID2
Always set HCR_TID2 to trap CTR_EL0, CCSIDR2_EL1, CLIDR_EL1, and
CSSELR_EL1. This saves a few lines of code and allows to employ their
access trap handlers for more purposes anticipated by the old
condition for setting HCR_TID2.

Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Link: https://lore.kernel.org/r/20230112023852.42012-6-akihiko.odaki@daynix.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-01-12 21:07:43 +00:00
Sean Christopherson
8d20bd6381 KVM: x86: Unify pr_fmt to use module name for all KVM modules
Define pr_fmt using KBUILD_MODNAME for all KVM x86 code so that printks
use consistent formatting across common x86, Intel, and AMD code.  In
addition to providing consistent print formatting, using KBUILD_MODNAME,
e.g. kvm_amd and kvm_intel, allows referencing SVM and VMX (and SEV and
SGX and ...) as technologies without generating weird messages, and
without causing naming conflicts with other kernel code, e.g. "SEV: ",
"tdx: ", "sgx: " etc.. are all used by the kernel for non-KVM subsystems.

Opportunistically move away from printk() for prints that need to be
modified anyways, e.g. to drop a manual "kvm: " prefix.

Opportunistically convert a few SGX WARNs that are similarly modified to
WARN_ONCE; in the very unlikely event that the WARNs fire, odds are good
that they would fire repeatedly and spam the kernel log without providing
unique information in each print.

Note, defining pr_fmt yields undesirable results for code that uses KVM's
printk wrappers, e.g. vcpu_unimpl().  But, that's a pre-existing problem
as SVM/kvm_amd already defines a pr_fmt, and thankfully use of KVM's
wrappers is relatively limited in KVM x86 code.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Message-Id: <20221130230934.1014142-35-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29 15:47:35 -05:00
Sean Christopherson
63a1bd8ad1 KVM: Drop arch hardware (un)setup hooks
Drop kvm_arch_hardware_setup() and kvm_arch_hardware_unsetup() now that
all implementations are nops.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>	# s390
Acked-by: Anup Patel <anup@brainfault.org>
Message-Id: <20221130230934.1014142-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-29 15:40:54 -05:00
Linus Torvalds
8fa590bf34 ARM64:
* Enable the per-vcpu dirty-ring tracking mechanism, together with an
   option to keep the good old dirty log around for pages that are
   dirtied by something other than a vcpu.
 
 * Switch to the relaxed parallel fault handling, using RCU to delay
   page table reclaim and giving better performance under load.
 
 * Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping option,
   which multi-process VMMs such as crosvm rely on (see merge commit 382b5b87a9:
   "Fix a number of issues with MTE, such as races on the tags being
   initialised vs the PG_mte_tagged flag as well as the lack of support
   for VM_SHARED when KVM is involved.  Patches from Catalin Marinas and
   Peter Collingbourne").
 
 * Merge the pKVM shadow vcpu state tracking that allows the hypervisor
   to have its own view of a vcpu, keeping that state private.
 
 * Add support for the PMUv3p5 architecture revision, bringing support
   for 64bit counters on systems that support it, and fix the
   no-quite-compliant CHAIN-ed counter support for the machines that
   actually exist out there.
 
 * Fix a handful of minor issues around 52bit VA/PA support (64kB pages
   only) as a prefix of the oncoming support for 4kB and 16kB pages.
 
 * Pick a small set of documentation and spelling fixes, because no
   good merge window would be complete without those.
 
 s390:
 
 * Second batch of the lazy destroy patches
 
 * First batch of KVM changes for kernel virtual != physical address support
 
 * Removal of a unused function
 
 x86:
 
 * Allow compiling out SMM support
 
 * Cleanup and documentation of SMM state save area format
 
 * Preserve interrupt shadow in SMM state save area
 
 * Respond to generic signals during slow page faults
 
 * Fixes and optimizations for the non-executable huge page errata fix.
 
 * Reprogram all performance counters on PMU filter change
 
 * Cleanups to Hyper-V emulation and tests
 
 * Process Hyper-V TLB flushes from a nested guest (i.e. from a L2 guest
   running on top of a L1 Hyper-V hypervisor)
 
 * Advertise several new Intel features
 
 * x86 Xen-for-KVM:
 
 ** Allow the Xen runstate information to cross a page boundary
 
 ** Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured
 
 ** Add support for 32-bit guests in SCHEDOP_poll
 
 * Notable x86 fixes and cleanups:
 
 ** One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0).
 
 ** Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few
    years back when eliminating unnecessary barriers when switching between
    vmcs01 and vmcs02.
 
 ** Clean up vmread_error_trampoline() to make it more obvious that params
    must be passed on the stack, even for x86-64.
 
 ** Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective
    of the current guest CPUID.
 
 ** Fudge around a race with TSC refinement that results in KVM incorrectly
    thinking a guest needs TSC scaling when running on a CPU with a
    constant TSC, but no hardware-enumerated TSC frequency.
 
 ** Advertise (on AMD) that the SMM_CTL MSR is not supported
 
 ** Remove unnecessary exports
 
 Generic:
 
 * Support for responding to signals during page faults; introduces
   new FOLL_INTERRUPTIBLE flag that was reviewed by mm folks
 
 Selftests:
 
 * Fix an inverted check in the access tracking perf test, and restore
   support for asserting that there aren't too many idle pages when
   running on bare metal.
 
 * Fix build errors that occur in certain setups (unsure exactly what is
   unique about the problematic setup) due to glibc overriding
   static_assert() to a variant that requires a custom message.
 
 * Introduce actual atomics for clear/set_bit() in selftests
 
 * Add support for pinning vCPUs in dirty_log_perf_test.
 
 * Rename the so called "perf_util" framework to "memstress".
 
 * Add a lightweight psuedo RNG for guest use, and use it to randomize
   the access pattern and write vs. read percentage in the memstress tests.
 
 * Add a common ucall implementation; code dedup and pre-work for running
   SEV (and beyond) guests in selftests.
 
 * Provide a common constructor and arch hook, which will eventually be
   used by x86 to automatically select the right hypercall (AMD vs. Intel).
 
 * A bunch of added/enabled/fixed selftests for ARM64, covering memslots,
   breakpoints, stage-2 faults and access tracking.
 
 * x86-specific selftest changes:
 
 ** Clean up x86's page table management.
 
 ** Clean up and enhance the "smaller maxphyaddr" test, and add a related
    test to cover generic emulation failure.
 
 ** Clean up the nEPT support checks.
 
 ** Add X86_PROPERTY_* framework to retrieve multi-bit CPUID values.
 
 ** Fix an ordering issue in the AMX test introduced by recent conversions
    to use kvm_cpu_has(), and harden the code to guard against similar bugs
    in the future.  Anything that tiggers caching of KVM's supported CPUID,
    kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if
    the caching occurs before the test opts in via prctl().
 
 Documentation:
 
 * Remove deleted ioctls from documentation
 
 * Clean up the docs for the x86 MSR filter.
 
 * Various fixes
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM64:

   - Enable the per-vcpu dirty-ring tracking mechanism, together with an
     option to keep the good old dirty log around for pages that are
     dirtied by something other than a vcpu.

   - Switch to the relaxed parallel fault handling, using RCU to delay
     page table reclaim and giving better performance under load.

   - Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping
     option, which multi-process VMMs such as crosvm rely on (see merge
     commit 382b5b87a9: "Fix a number of issues with MTE, such as
     races on the tags being initialised vs the PG_mte_tagged flag as
     well as the lack of support for VM_SHARED when KVM is involved.
     Patches from Catalin Marinas and Peter Collingbourne").

   - Merge the pKVM shadow vcpu state tracking that allows the
     hypervisor to have its own view of a vcpu, keeping that state
     private.

   - Add support for the PMUv3p5 architecture revision, bringing support
     for 64bit counters on systems that support it, and fix the
     no-quite-compliant CHAIN-ed counter support for the machines that
     actually exist out there.

   - Fix a handful of minor issues around 52bit VA/PA support (64kB
     pages only) as a prefix of the oncoming support for 4kB and 16kB
     pages.

   - Pick a small set of documentation and spelling fixes, because no
     good merge window would be complete without those.

  s390:

   - Second batch of the lazy destroy patches

   - First batch of KVM changes for kernel virtual != physical address
     support

   - Removal of a unused function

  x86:

   - Allow compiling out SMM support

   - Cleanup and documentation of SMM state save area format

   - Preserve interrupt shadow in SMM state save area

   - Respond to generic signals during slow page faults

   - Fixes and optimizations for the non-executable huge page errata
     fix.

   - Reprogram all performance counters on PMU filter change

   - Cleanups to Hyper-V emulation and tests

   - Process Hyper-V TLB flushes from a nested guest (i.e. from a L2
     guest running on top of a L1 Hyper-V hypervisor)

   - Advertise several new Intel features

   - x86 Xen-for-KVM:

      - Allow the Xen runstate information to cross a page boundary

      - Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured

      - Add support for 32-bit guests in SCHEDOP_poll

   - Notable x86 fixes and cleanups:

      - One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0).

      - Reinstate IBPB on emulated VM-Exit that was incorrectly dropped
        a few years back when eliminating unnecessary barriers when
        switching between vmcs01 and vmcs02.

      - Clean up vmread_error_trampoline() to make it more obvious that
        params must be passed on the stack, even for x86-64.

      - Let userspace set all supported bits in MSR_IA32_FEAT_CTL
        irrespective of the current guest CPUID.

      - Fudge around a race with TSC refinement that results in KVM
        incorrectly thinking a guest needs TSC scaling when running on a
        CPU with a constant TSC, but no hardware-enumerated TSC
        frequency.

      - Advertise (on AMD) that the SMM_CTL MSR is not supported

      - Remove unnecessary exports

  Generic:

   - Support for responding to signals during page faults; introduces
     new FOLL_INTERRUPTIBLE flag that was reviewed by mm folks

  Selftests:

   - Fix an inverted check in the access tracking perf test, and restore
     support for asserting that there aren't too many idle pages when
     running on bare metal.

   - Fix build errors that occur in certain setups (unsure exactly what
     is unique about the problematic setup) due to glibc overriding
     static_assert() to a variant that requires a custom message.

   - Introduce actual atomics for clear/set_bit() in selftests

   - Add support for pinning vCPUs in dirty_log_perf_test.

   - Rename the so called "perf_util" framework to "memstress".

   - Add a lightweight psuedo RNG for guest use, and use it to randomize
     the access pattern and write vs. read percentage in the memstress
     tests.

   - Add a common ucall implementation; code dedup and pre-work for
     running SEV (and beyond) guests in selftests.

   - Provide a common constructor and arch hook, which will eventually
     be used by x86 to automatically select the right hypercall (AMD vs.
     Intel).

   - A bunch of added/enabled/fixed selftests for ARM64, covering
     memslots, breakpoints, stage-2 faults and access tracking.

   - x86-specific selftest changes:

      - Clean up x86's page table management.

      - Clean up and enhance the "smaller maxphyaddr" test, and add a
        related test to cover generic emulation failure.

      - Clean up the nEPT support checks.

      - Add X86_PROPERTY_* framework to retrieve multi-bit CPUID values.

      - Fix an ordering issue in the AMX test introduced by recent
        conversions to use kvm_cpu_has(), and harden the code to guard
        against similar bugs in the future. Anything that tiggers
        caching of KVM's supported CPUID, kvm_cpu_has() in this case,
        effectively hides opt-in XSAVE features if the caching occurs
        before the test opts in via prctl().

  Documentation:

   - Remove deleted ioctls from documentation

   - Clean up the docs for the x86 MSR filter.

   - Various fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (361 commits)
  KVM: x86: Add proper ReST tables for userspace MSR exits/flags
  KVM: selftests: Allocate ucall pool from MEM_REGION_DATA
  KVM: arm64: selftests: Align VA space allocator with TTBR0
  KVM: arm64: Fix benign bug with incorrect use of VA_BITS
  KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow
  KVM: x86: Advertise that the SMM_CTL MSR is not supported
  KVM: x86: remove unnecessary exports
  KVM: selftests: Fix spelling mistake "probabalistic" -> "probabilistic"
  tools: KVM: selftests: Convert clear/set_bit() to actual atomics
  tools: Drop "atomic_" prefix from atomic test_and_set_bit()
  tools: Drop conflicting non-atomic test_and_{clear,set}_bit() helpers
  KVM: selftests: Use non-atomic clear/set bit helpers in KVM tests
  perf tools: Use dedicated non-atomic clear/set bit helpers
  tools: Take @bit as an "unsigned long" in {clear,set}_bit() helpers
  KVM: arm64: selftests: Enable single-step without a "full" ucall()
  KVM: x86: fix APICv/x2AVIC disabled when vm reboot by itself
  KVM: Remove stale comment about KVM_REQ_UNHALT
  KVM: Add missing arch for KVM_CREATE_DEVICE and KVM_{SET,GET}_DEVICE_ATTR
  KVM: Reference to kvm_userspace_memory_region in doc and comments
  KVM: Delete all references to removed KVM_SET_MEMORY_ALIAS ioctl
  ...
2022-12-15 11:12:21 -08:00
Marc Zyngier
118bc846d4 Merge branch kvm-arm64/pmu-unchained into kvmarm-master/next
* kvm-arm64/pmu-unchained:
  : .
  : PMUv3 fixes and improvements:
  :
  : - Make the CHAIN event handling strictly follow the architecture
  :
  : - Add support for PMUv3p5 (64bit counters all the way)
  :
  : - Various fixes and cleanups
  : .
  KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow
  KVM: arm64: PMU: Sanitise PMCR_EL0.LP on first vcpu run
  KVM: arm64: PMU: Simplify PMCR_EL0 reset handling
  KVM: arm64: PMU: Replace version number '0' with ID_AA64DFR0_EL1_PMUVer_NI
  KVM: arm64: PMU: Make kvm_pmc the main data structure
  KVM: arm64: PMU: Simplify vcpu computation on perf overflow notification
  KVM: arm64: PMU: Allow PMUv3p5 to be exposed to the guest
  KVM: arm64: PMU: Implement PMUv3p5 long counter support
  KVM: arm64: PMU: Allow ID_DFR0_EL1.PerfMon to be set from userspace
  KVM: arm64: PMU: Allow ID_AA64DFR0_EL1.PMUver to be set from userspace
  KVM: arm64: PMU: Move the ID_AA64DFR0_EL1.PMUver limit to VM creation
  KVM: arm64: PMU: Do not let AArch32 change the counters' top 32 bits
  KVM: arm64: PMU: Simplify setting a counter to a specific value
  KVM: arm64: PMU: Add counter_index_to_*reg() helpers
  KVM: arm64: PMU: Only narrow counters that are not 64bit wide
  KVM: arm64: PMU: Narrow the overflow checking when required
  KVM: arm64: PMU: Distinguish between 64bit counter and 64bit overflow
  KVM: arm64: PMU: Always advertise the CHAIN event
  KVM: arm64: PMU: Align chained counter implementation with architecture pseudocode
  arm64: Add ID_DFR0_EL1.PerfMon values for PMUv3p7 and IMP_DEF

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-12-05 14:38:44 +00:00
Mark Brown
baa8515281 arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE
When we save the state for the floating point registers this can be done
in the form visible through either the FPSIMD V registers or the SVE Z and
P registers. At present we track which format is currently used based on
TIF_SVE and the SME streaming mode state but particularly in the SVE case
this limits our options for optimising things, especially around syscalls.
Introduce a new enum which we place together with saved floating point
state in both thread_struct and the KVM guest state which explicitly
states which format is active and keep it up to date when we change it.

At present we do not use this state except to verify that it has the
expected value when loading the state, future patches will introduce
functional changes.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221115094640.112848-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2022-11-29 15:01:56 +00:00
Marc Zyngier
3d0dba5764 KVM: arm64: PMU: Move the ID_AA64DFR0_EL1.PMUver limit to VM creation
As further patches will enable the selection of a PMU revision
from userspace, sample the supported PMU revision at VM creation
time, rather than building each time the ID_AA64DFR0_EL1 register
is accessed.

This shouldn't result in any change in behaviour.

Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221113163832.3154370-11-maz@kernel.org
2022-11-19 12:56:39 +00:00
Quentin Perret
f41dff4efb KVM: arm64: Return guest memory from EL2 via dedicated teardown memcache
Rather than relying on the host to free the previously-donated pKVM
hypervisor VM pages explicitly on teardown, introduce a dedicated
teardown memcache which allows the host to reclaim guest memory
resources without having to keep track of all of the allocations made by
the pKVM hypervisor at EL2.

Tested-by: Vincent Donnefort <vdonnefort@google.com>
Co-developed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
[maz: dropped __maybe_unused from unmap_donated_memory_noclear()]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-21-will@kernel.org
2022-11-11 17:18:58 +00:00
Quentin Perret
315775ff7c KVM: arm64: Consolidate stage-2 initialisation into a single function
The initialisation of guest stage-2 page-tables is currently split
across two functions: kvm_init_stage2_mmu() and kvm_arm_setup_stage2().
That is presumably for historical reasons as kvm_arm_setup_stage2()
originates from the (now defunct) KVM port for 32-bit Arm.

Simplify this code path by merging both functions into one, taking care
to map the 'struct kvm' into the hypervisor stage-1 early on in order to
simplify the failure path.

Tested-by: Vincent Donnefort <vdonnefort@google.com>
Co-developed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-19-will@kernel.org
2022-11-11 17:16:25 +00:00
Quentin Perret
717a7eebac KVM: arm64: Add generic hyp_memcache helpers
The host at EL1 and the pKVM hypervisor at EL2 will soon need to
exchange memory pages dynamically for creating and destroying VM state.

Indeed, the hypervisor will rely on the host to donate memory pages it
can use to create guest stage-2 page-tables and to store VM and vCPU
metadata. In order to ease this process, introduce a
'struct hyp_memcache' which is essentially a linked list of available
pages, indexed by physical addresses so that it can be passed
meaningfully between the different virtual address spaces configured at
EL1 and EL2.

Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-18-will@kernel.org
2022-11-11 17:16:25 +00:00
Fuad Tabba
9d0c063a4d KVM: arm64: Instantiate pKVM hypervisor VM and vCPU structures from EL1
With the pKVM hypervisor at EL2 now offering hypercalls to the host for
creating and destroying VM and vCPU structures, plumb these in to the
existing arm64 KVM backend to ensure that the hypervisor data structures
are allocated and initialised on first vCPU run for a pKVM guest.

In the host, 'struct kvm_protected_vm' is introduced to hold the handle
of the pKVM VM instance as well as to track references to the memory
donated to the hypervisor so that it can be freed back to the host
allocator following VM teardown. The stage-2 page-table, hypervisor VM
and vCPU structures are allocated separately so as to avoid the need for
a large physically-contiguous allocation in the host at run-time.

Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-14-will@kernel.org
2022-11-11 17:16:24 +00:00
Fuad Tabba
a1ec5c70d3 KVM: arm64: Add infrastructure to create and track pKVM instances at EL2
Introduce a global table (and lock) to track pKVM instances at EL2, and
provide hypercalls that can be used by the untrusted host to create and
destroy pKVM VMs and their vCPUs. pKVM VM/vCPU state is directly
accessible only by the trusted hypervisor (EL2).

Each pKVM VM is directly associated with an untrusted host KVM instance,
and is referenced by the host using an opaque handle. Future patches
will provide hypercalls to allow the host to initialize/set/get pKVM
VM/vCPU state using the opaque handle.

Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Co-developed-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
[maz: silence warning on unmap_donated_memory_noclear()]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221110190259.26861-13-will@kernel.org
2022-11-11 17:16:05 +00:00
Reiji Watanabe
370531d1e9 KVM: arm64: Clear PSTATE.SS when the Software Step state was Active-pending
While userspace enables single-step, if the Software Step state at the
last guest exit was "Active-pending", clear PSTATE.SS on guest entry
to restore the state.

Currently, KVM sets PSTATE.SS to 1 on every guest entry while userspace
enables single-step for the vCPU (with KVM_GUESTDBG_SINGLESTEP).
It means KVM always makes the vCPU's Software Step state
"Active-not-pending" on the guest entry, which lets the VCPU perform
single-step (then Software Step exception is taken). This could cause
extra single-step (without returning to userspace) if the Software Step
state at the last guest exit was "Active-pending" (i.e. the last
exit was triggered by an asynchronous exception after the single-step
is performed, but before the Software Step exception is taken.
See "Figure D2-3 Software step state machine" and "D2.12.7 Behavior
in the active-pending state" in ARM DDI 0487I.a for more info about
this behavior).

Fix this by clearing PSTATE.SS on guest entry if the Software Step state
at the last exit was "Active-pending" so that KVM restore the state (and
the exception is taken before further single-step is performed).

Fixes: 337b99bf7e ("KVM: arm64: guest debug, add support for single-step")
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220917010600.532642-3-reijiw@google.com
2022-09-19 10:48:53 +01:00
Reiji Watanabe
34fbdee086 KVM: arm64: Preserve PSTATE.SS for the guest while single-step is enabled
Preserve the PSTATE.SS value for the guest while userspace enables
single-step (i.e. while KVM manipulates the PSTATE.SS) for the vCPU.

Currently, while userspace enables single-step for the vCPU
(with KVM_GUESTDBG_SINGLESTEP), KVM sets PSTATE.SS to 1 on every
guest entry, not saving its original value.
When userspace disables single-step, KVM doesn't restore the original
value for the subsequent guest entry (use the current value instead).
Exception return instructions copy PSTATE.SS from SPSR_ELx.SS
only in certain cases when single-step is enabled (and set it to 0
in other cases). So, the value matters only when the guest enables
single-step (and when the guest's Software step state isn't affected
by single-step enabled by userspace, practically), though.

Fix this by preserving the original PSTATE.SS value while userspace
enables single-step, and restoring the value once it is disabled.

This fix modifies the behavior of GET_ONE_REG/SET_ONE_REG for the
PSTATE.SS while single-step is enabled by userspace.
Presently, GET_ONE_REG/SET_ONE_REG gets/sets the current PSTATE.SS
value, which KVM will override on the next guest entry (i.e. the
value userspace gets/sets is not used for the next guest entry).
With this patch, GET_ONE_REG/SET_ONE_REG will get/set the guest's
preserved value, which KVM will preserve and try to restore after
single-step is disabled.

Fixes: 337b99bf7e ("KVM: arm64: guest debug, add support for single-step")
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220917010600.532642-2-reijiw@google.com
2022-09-19 10:48:53 +01:00
Oliver Upton
f3c6efc72f KVM: arm64: Treat PMCR_EL1.LC as RES1 on asymmetric systems
KVM does not support AArch32 on asymmetric systems. To that end, enforce
AArch64-only behavior on PMCR_EL1.LC when on an asymmetric system.

Fixes: 2122a83331 ("arm64: Allow mismatched 32-bit EL0 support")
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220816192554.1455559-2-oliver.upton@linux.dev
2022-08-17 10:29:07 +01:00
Marc Zyngier
ae98a4a989 Merge branch kvm-arm64/sysreg-cleanup-5.20 into kvmarm-master/next
* kvm-arm64/sysreg-cleanup-5.20:
  : .
  : Long overdue cleanup of the sysreg userspace access,
  : with extra scrubbing on the vgic side of things.
  : From the cover letter:
  :
  : "Schspa Shi recently reported[1] that some of the vgic code interacting
  : with userspace was reading uninitialised stack memory, and although
  : that read wasn't used any further, it prompted me to revisit this part
  : of the code.
  :
  : Needless to say, this area of the kernel is pretty crufty, and shows a
  : bunch of issues in other parts of the KVM/arm64 infrastructure. This
  : series tries to remedy a bunch of them:
  :
  : - Sanitise the way we deal with sysregs from userspace: at the moment,
  :   each and every .set_user/.get_user callback has to implement its own
  :   userspace accesses (directly or indirectly). It'd be much better if
  :   that was centralised so that we can reason about it.
  :
  : - Enforce that all AArch64 sysregs are 64bit. Always. This was sort of
  :   implied by the code, but it took some effort to convince myself that
  :   this was actually the case.
  :
  : - Move the vgic-v3 sysreg userspace accessors to the userspace
  :   callbacks instead of hijacking the vcpu trap callback. This allows
  :   us to reuse the sysreg infrastructure.
  :
  : - Consolidate userspace accesses for both GICv2, GICv3 and common code
  :   as much as possible.
  :
  : - Cleanup a bunch of not-very-useful helpers, tidy up some of the code
  :   as we touch it.
  :
  : [1] https://lore.kernel.org/r/m2h740zz1i.fsf@gmail.com"
  : .
  KVM: arm64: Get rid or outdated comments
  KVM: arm64: Descope kvm_arm_sys_reg_{get,set}_reg()
  KVM: arm64: Get rid of find_reg_by_id()
  KVM: arm64: vgic: Tidy-up calls to vgic_{get,set}_common_attr()
  KVM: arm64: vgic: Consolidate userspace access for base address setting
  KVM: arm64: vgic-v2: Add helper for legacy dist/cpuif base address setting
  KVM: arm64: vgic: Use {get,put}_user() instead of copy_{from.to}_user
  KVM: arm64: vgic-v2: Consolidate userspace access for MMIO registers
  KVM: arm64: vgic-v3: Consolidate userspace access for MMIO registers
  KVM: arm64: vgic-v3: Use u32 to manage the line level from userspace
  KVM: arm64: vgic-v3: Convert userspace accessors over to FIELD_GET/FIELD_PREP
  KVM: arm64: vgic-v3: Make the userspace accessors use sysreg API
  KVM: arm64: vgic-v3: Push user access into vgic_v3_cpu_sysregs_uaccess()
  KVM: arm64: vgic-v3: Simplify vgic_v3_has_cpu_sysregs_attr()
  KVM: arm64: Get rid of reg_from/to_user()
  KVM: arm64: Consolidate sysreg userspace accesses
  KVM: arm64: Rely on index_to_param() for size checks on userspace access
  KVM: arm64: Introduce generic get_user/set_user helpers for system registers
  KVM: arm64: Reorder handling of invariant sysregs from userspace
  KVM: arm64: Add get_reg_by_id() as a sys_reg_desc retrieving helper

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-07-17 11:55:58 +01:00
Marc Zyngier
c5332898dc KVM: arm64: Descope kvm_arm_sys_reg_{get,set}_reg()
Having kvm_arm_sys_reg_get_reg and co in kvm_host.h gives the
impression that these functions are free to be called from
anywhere.

Not quite. They really are tied to out internal sysreg handling,
and they would be better off in the sys_regs.h header, which is
private. kvm_host.h could also get a bit of a diet, so let's
just do that.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-07-17 11:55:33 +01:00
Marc Zyngier
dc94f89ae6 Merge branch kvm-arm64/burn-the-flags into kvmarm-master/next
* kvm-arm64/burn-the-flags:
  : .
  : Rework the per-vcpu flags to make them more manageable,
  : splitting them in different sets that have specific
  : uses:
  :
  : - configuration flags
  : - input to the world-switch
  : - state bookkeeping for the kernel itself
  :
  : The FP tracking is also simplified and tracked outside
  : of the flags as a separate state.
  : .
  KVM: arm64: Move the handling of !FP outside of the fast path
  KVM: arm64: Document why pause cannot be turned into a flag
  KVM: arm64: Reduce the size of the vcpu flag members
  KVM: arm64: Add build-time sanity checks for flags
  KVM: arm64: Warn when PENDING_EXCEPTION and INCREMENT_PC are set together
  KVM: arm64: Convert vcpu sysregs_loaded_on_cpu to a state flag
  KVM: arm64: Kill unused vcpu flags field
  KVM: arm64: Move vcpu WFIT flag to the state flag set
  KVM: arm64: Move vcpu ON_UNSUPPORTED_CPU flag to the state flag set
  KVM: arm64: Move vcpu SVE/SME flags to the state flag set
  KVM: arm64: Move vcpu debug/SPE/TRBE flags to the input flag set
  KVM: arm64: Move vcpu PC/Exception flags to the input flag set
  KVM: arm64: Move vcpu configuration flags into their own set
  KVM: arm64: Add three sets of flags to the vcpu state
  KVM: arm64: Add helpers to manipulate vcpu flags among a set
  KVM: arm64: Move FP state ownership from flag to a tristate
  KVM: arm64: Drop FP_FOREIGN_STATE from the hypervisor code

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-29 10:30:10 +01:00
Marc Zyngier
0fa4a3137e KVM: arm64: Document why pause cannot be turned into a flag
It would be tempting to turn the 'pause' state into a flag.

However, this cannot easily be done as it is updated out of context,
while all the flags expect to only be updated from the vcpu thread.
Turning it into a flag would require to make all flag updates
atomic, which isn't necessary desireable.

Document this, and take this opportunity to move the field next
to the flag sets, filling a hole in the vcpu structure.

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-29 10:23:51 +01:00
Marc Zyngier
54ddda919c KVM: arm64: Reduce the size of the vcpu flag members
Now that we can detect flags overflowing their container, reduce
the size of all flag set members in the vcpu struct, turning them
into 8bit quantities.

Even with the FP state enum occupying 32bit, the whole of the state
that was represented by flags is smaller by one byte. Profit!

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-29 10:23:46 +01:00
Marc Zyngier
5a3984f4ec KVM: arm64: Add build-time sanity checks for flags
Flags are great, but flags can also be dangerous: it is easy
to encode a flag that is bigger than its container (unless the
container is a u64), and it is easy to construct a flag value
that doesn't fit in the mask that is associated with it.

Add a couple of build-time sanity checks that ensure we catch
these two cases.

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-29 10:23:41 +01:00
Marc Zyngier
30b6ab45f8 KVM: arm64: Convert vcpu sysregs_loaded_on_cpu to a state flag
The aptly named boolean 'sysregs_loaded_on_cpu' tracks whether
some of the vcpu system registers are resident on the physical
CPU when running in VHE mode.

This is obviously a flag in hidding, so let's convert it to
a state flag, since this is solely a host concern (the hypervisor
itself always knows which state we're in).

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-29 10:23:32 +01:00
Marc Zyngier
781e3ae148 KVM: arm64: Kill unused vcpu flags field
Horray, we have now sorted all the preexisting flags, and the
'flags' field is now unused. Get rid of it while nobody is
looking.

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-29 10:23:28 +01:00
Marc Zyngier
eebc538d8e KVM: arm64: Move vcpu WFIT flag to the state flag set
The host kernel uses the WFIT flag to remember that a vcpu has used
this instruction and wake it up as required. Move it to the state
set, as nothing in the hypervisor uses this information.

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-29 10:23:23 +01:00
Marc Zyngier
aff3ccd732 KVM: arm64: Move vcpu ON_UNSUPPORTED_CPU flag to the state flag set
The ON_UNSUPPORTED_CPU flag is only there to track the sad fact
that we have ended-up on a CPU where we cannot really run.

Since this is only for the host kernel's use, move it to the state
set.

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-29 10:23:19 +01:00
Marc Zyngier
0affa37fcd KVM: arm64: Move vcpu SVE/SME flags to the state flag set
The two HOST_{SVE,SME}_ENABLED are only used for the host kernel
to track its own state across a vcpu run so that it can be fully
restored.

Move these flags to the so called state set.

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-29 10:23:14 +01:00
Marc Zyngier
b1da49088a KVM: arm64: Move vcpu debug/SPE/TRBE flags to the input flag set
The three debug flags (which deal with the debug registers, SPE and
TRBE) all are input flags to the hypervisor code.

Move them into the input set and convert them to the new accessors.

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-29 10:23:03 +01:00
Marc Zyngier
699bb2e0c6 KVM: arm64: Move vcpu PC/Exception flags to the input flag set
The PC update flags (which also deal with exception injection)
is one of the most complicated use of the flag we have. Make it
more fool prof by:

- moving it over to the new accessors and assign it to the
  input flag set

- turn the combination of generic ELx flags with another flag
  indicating the target EL itself into an explicit set of
  flags for each EL and vector combination

- add a new accessor to pend the exception

This is otherwise a pretty straightformward conversion.

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-10 09:54:34 +01:00
Marc Zyngier
4c0680d394 KVM: arm64: Move vcpu configuration flags into their own set
The KVM_ARM64_{GUEST_HAS_SVE,VCPU_SVE_FINALIZED,GUEST_HAS_PTRAUTH}
flags are purely configuration flags. Once set, they are never cleared,
but evaluated all over the code base.

Move these three flags into the configuration set in one go, using
the new accessors, and take this opportunity to drop the KVM_ARM64_
prefix which doesn't provide any help.

Reviewed-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-09 15:43:46 +01:00
Marc Zyngier
bcbfb588cf KVM: arm64: Drop stale comment
The layout of 'struct kvm_vcpu_arch' has evolved significantly since
the initial port of KVM/arm64, so remove the stale comment suggesting
that a prefix of the structure is used exclusively from assembly code.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220609121223.2551-7-will@kernel.org
2022-06-09 13:24:02 +01:00
Marc Zyngier
690bacb83b KVM: arm64: Add three sets of flags to the vcpu state
It so appears that each of the vcpu flags is really belonging to
one of three categories:

- a configuration flag, set once and for all
- an input flag generated by the kernel for the hypervisor to use
- a state flag that is only for the kernel's own bookkeeping

As we are going to split all the existing flags into these three
sets, introduce all three in one go.

No functional change other than a bit of bloat...

Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-09 12:02:12 +01:00
Marc Zyngier
e87abb73e5 KVM: arm64: Add helpers to manipulate vcpu flags among a set
Careful analysis of the vcpu flags show that this is a mix of
configuration, communication between the host and the hypervisor,
as well as anciliary state that has no consistency. It'd be a lot
better if we could split these flags into consistent categories.

However, even if we split these flags apart, we want to make sure
that each flag can only be applied to its own set, and not across
sets.

To achieve this, use a preprocessor hack so that each flag is always
associated with:

- the set that contains it,

- a mask that describe all the bits that contain it (for a simple
  flag, this is the same thing as the flag itself, but we will
  eventually have values that cover multiple bits at once).

Each flag is thus a triplet that is not directly usable as a value,
but used by three helpers that allow the flag to be set, cleared,
and fetched. By mandating the use of such helper, we can easily
enforce that a flag can only be used with the set it belongs to.

Finally, one last helper "unpacks" the raw value from the triplet
that represents a flag, which is useful for multi-bit values that
need to be enumerated (in a switch statement, for example).

Further patches will start making use of this infrastructure.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-06-09 12:02:06 +01:00
Marc Zyngier
f8077b0d59 KVM: arm64: Move FP state ownership from flag to a tristate
The KVM FP code uses a pair of flags to denote three states:

- FP_ENABLED set: the guest owns the FP state
- FP_HOST set: the host owns the FP state
- FP_ENABLED and FP_HOST clear: nobody owns the FP state at all

and both flags set is an illegal state, which nothing ever checks
for...

As it turns out, this isn't really a good match for flags, and
we'd be better off if this was a simpler tristate, each state
having a name that actually reflect the state:

- FP_STATE_FREE
- FP_STATE_HOST_OWNED
- FP_STATE_GUEST_OWNED

Kill the two flags, and move over to an enum encoding these
three states. This results in less confusing code, and less risk of
ending up in the uncharted territory of a 4th state if we forget
to clear one of the two flags.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
2022-06-09 12:01:58 +01:00
Marc Zyngier
e9ada6c208 KVM: arm64: Drop FP_FOREIGN_STATE from the hypervisor code
The vcpu KVM_ARM64_FP_FOREIGN_FPSTATE flag tracks the thread's own
TIF_FOREIGN_FPSTATE so that we can evaluate just before running
the vcpu whether it the FP regs contain something that is owned
by the vcpu or not by updating the rest of the FP flags.

We do this in the hypervisor code in order to make sure we're
in a context where we are not interruptible. But we already
have a hook in the run loop to generate this flag. We may as
well update the FP flags directly and save the pointless flag
tracking.

Whilst we're at it, rename update_fp_enabled() to guest_owns_fp_regs()
to indicate what the leftover of this helper actually do.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
2022-06-09 12:01:51 +01:00
Linus Torvalds
bf9095424d S390:
* ultravisor communication device driver
 
 * fix TEID on terminating storage key ops
 
 RISC-V:
 
 * Added Sv57x4 support for G-stage page table
 
 * Added range based local HFENCE functions
 
 * Added remote HFENCE functions based on VCPU requests
 
 * Added ISA extension registers in ONE_REG interface
 
 * Updated KVM RISC-V maintainers entry to cover selftests support
 
 ARM:
 
 * Add support for the ARMv8.6 WFxT extension
 
 * Guard pages for the EL2 stacks
 
 * Trap and emulate AArch32 ID registers to hide unsupported features
 
 * Ability to select and save/restore the set of hypercalls exposed
   to the guest
 
 * Support for PSCI-initiated suspend in collaboration with userspace
 
 * GICv3 register-based LPI invalidation support
 
 * Move host PMU event merging into the vcpu data structure
 
 * GICv3 ITS save/restore fixes
 
 * The usual set of small-scale cleanups and fixes
 
 x86:
 
 * New ioctls to get/set TSC frequency for a whole VM
 
 * Allow userspace to opt out of hypercall patching
 
 * Only do MSR filtering for MSRs accessed by rdmsr/wrmsr
 
 AMD SEV improvements:
 
 * Add KVM_EXIT_SHUTDOWN metadata for SEV-ES
 
 * V_TSC_AUX support
 
 Nested virtualization improvements for AMD:
 
 * Support for "nested nested" optimizations (nested vVMLOAD/VMSAVE,
   nested vGIF)
 
 * Allow AVIC to co-exist with a nested guest running
 
 * Fixes for LBR virtualizations when a nested guest is running,
   and nested LBR virtualization support
 
 * PAUSE filtering for nested hypervisors
 
 Guest support:
 
 * Decoupling of vcpu_is_preempted from PV spinlocks
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "S390:

   - ultravisor communication device driver

   - fix TEID on terminating storage key ops

  RISC-V:

   - Added Sv57x4 support for G-stage page table

   - Added range based local HFENCE functions

   - Added remote HFENCE functions based on VCPU requests

   - Added ISA extension registers in ONE_REG interface

   - Updated KVM RISC-V maintainers entry to cover selftests support

  ARM:

   - Add support for the ARMv8.6 WFxT extension

   - Guard pages for the EL2 stacks

   - Trap and emulate AArch32 ID registers to hide unsupported features

   - Ability to select and save/restore the set of hypercalls exposed to
     the guest

   - Support for PSCI-initiated suspend in collaboration with userspace

   - GICv3 register-based LPI invalidation support

   - Move host PMU event merging into the vcpu data structure

   - GICv3 ITS save/restore fixes

   - The usual set of small-scale cleanups and fixes

  x86:

   - New ioctls to get/set TSC frequency for a whole VM

   - Allow userspace to opt out of hypercall patching

   - Only do MSR filtering for MSRs accessed by rdmsr/wrmsr

  AMD SEV improvements:

   - Add KVM_EXIT_SHUTDOWN metadata for SEV-ES

   - V_TSC_AUX support

  Nested virtualization improvements for AMD:

   - Support for "nested nested" optimizations (nested vVMLOAD/VMSAVE,
     nested vGIF)

   - Allow AVIC to co-exist with a nested guest running

   - Fixes for LBR virtualizations when a nested guest is running, and
     nested LBR virtualization support

   - PAUSE filtering for nested hypervisors

  Guest support:

   - Decoupling of vcpu_is_preempted from PV spinlocks"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (199 commits)
  KVM: x86: Fix the intel_pt PMI handling wrongly considered from guest
  KVM: selftests: x86: Sync the new name of the test case to .gitignore
  Documentation: kvm: reorder ARM-specific section about KVM_SYSTEM_EVENT_SUSPEND
  x86, kvm: use correct GFP flags for preemption disabled
  KVM: LAPIC: Drop pending LAPIC timer injection when canceling the timer
  x86/kvm: Alloc dummy async #PF token outside of raw spinlock
  KVM: x86: avoid calling x86 emulator without a decoded instruction
  KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak
  x86/fpu: KVM: Set the base guest FPU uABI size to sizeof(struct kvm_xsave)
  s390/uv_uapi: depend on CONFIG_S390
  KVM: selftests: x86: Fix test failure on arch lbr capable platforms
  KVM: LAPIC: Trace LAPIC timer expiration on every vmentry
  KVM: s390: selftest: Test suppression indication on key prot exception
  KVM: s390: Don't indicate suppression on dirtying, failing memop
  selftests: drivers/s390x: Add uvdevice tests
  drivers/s390/char: Add Ultravisor io device
  MAINTAINERS: Update KVM RISC-V entry to cover selftests support
  RISC-V: KVM: Introduce ISA extension register
  RISC-V: KVM: Cleanup stale TLB entries when host CPU changes
  RISC-V: KVM: Add remote HFENCE functions based on VCPU requests
  ...
2022-05-26 14:20:14 -07:00
Paolo Bonzini
47e8eec832 KVM/arm64 updates for 5.19
- Add support for the ARMv8.6 WFxT extension
 
 - Guard pages for the EL2 stacks
 
 - Trap and emulate AArch32 ID registers to hide unsupported features
 
 - Ability to select and save/restore the set of hypercalls exposed
   to the guest
 
 - Support for PSCI-initiated suspend in collaboration with userspace
 
 - GICv3 register-based LPI invalidation support
 
 - Move host PMU event merging into the vcpu data structure
 
 - GICv3 ITS save/restore fixes
 
 - The usual set of small-scale cleanups and fixes
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Merge tag 'kvmarm-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for 5.19

- Add support for the ARMv8.6 WFxT extension

- Guard pages for the EL2 stacks

- Trap and emulate AArch32 ID registers to hide unsupported features

- Ability to select and save/restore the set of hypercalls exposed
  to the guest

- Support for PSCI-initiated suspend in collaboration with userspace

- GICv3 register-based LPI invalidation support

- Move host PMU event merging into the vcpu data structure

- GICv3 ITS save/restore fixes

- The usual set of small-scale cleanups and fixes

[Due to the conflict, KVM_SYSTEM_EVENT_SEV_TERM is relocated
 from 4 to 6. - Paolo]
2022-05-25 05:09:23 -04:00
Catalin Marinas
0616ea3f1b Merge branch 'for-next/esr-elx-64-bit' into for-next/core
* for-next/esr-elx-64-bit:
  : Treat ESR_ELx as a 64-bit register.
  KVM: arm64: uapi: Add kvm_debug_exit_arch.hsr_high
  KVM: arm64: Treat ESR_EL2 as a 64-bit register
  arm64: Treat ESR_ELx as a 64-bit register
  arm64: compat: Do not treat syscall number as ESR_ELx for a bad syscall
  arm64: Make ESR_ELx_xVC_IMM_MASK compatible with assembly
2022-05-20 18:51:54 +01:00
Marc Zyngier
822ca7f82b Merge branch kvm-arm64/misc-5.19 into kvmarm-master/next
* kvm-arm64/misc-5.19:
  : .
  : Misc fixes and general improvements for KVMM/arm64:
  :
  : - Better handle out of sequence sysregs in the global tables
  :
  : - Remove a couple of unnecessary loads from constant pool
  :
  : - Drop unnecessary pKVM checks
  :
  : - Add all known M1 implementations to the SEIS workaround
  :
  : - Cleanup kerneldoc warnings
  : .
  KVM: arm64: vgic-v3: List M1 Pro/Max as requiring the SEIS workaround
  KVM: arm64: pkvm: Don't mask already zeroed FEAT_SVE
  KVM: arm64: pkvm: Drop unnecessary FP/SIMD trap handler
  KVM: arm64: nvhe: Eliminate kernel-doc warnings
  KVM: arm64: Avoid unnecessary absolute addressing via literals
  KVM: arm64: Print emulated register table name when it is unsorted
  KVM: arm64: Don't BUG_ON() if emulated register table is unsorted

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-05-16 17:48:36 +01:00
Marc Zyngier
8794b4f510 Merge branch kvm-arm64/per-vcpu-host-pmu-data into kvmarm-master/next
* kvm-arm64/per-vcpu-host-pmu-data:
  : .
  : Pass the host PMU state in the vcpu to avoid the use of additional
  : shared memory between EL1 and EL2 (this obviously only applies
  : to nVHE and Protected setups).
  :
  : Patches courtesy of Fuad Tabba.
  : .
  KVM: arm64: pmu: Restore compilation when HW_PERF_EVENTS isn't selected
  KVM: arm64: Reenable pmu in Protected Mode
  KVM: arm64: Pass pmu events to hyp via vcpu
  KVM: arm64: Repack struct kvm_pmu to reduce size
  KVM: arm64: Wrapper for getting pmu_events

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-05-16 17:48:36 +01:00
Marc Zyngier
3b8e21e3c3 Merge branch kvm-arm64/psci-suspend into kvmarm-master/next
* kvm-arm64/psci-suspend:
  : .
  : Add support for PSCI SYSTEM_SUSPEND and allow userspace to
  : filter the wake-up events.
  :
  : Patches courtesy of Oliver.
  : .
  Documentation: KVM: Fix title level for PSCI_SUSPEND
  selftests: KVM: Test SYSTEM_SUSPEND PSCI call
  selftests: KVM: Refactor psci_test to make it amenable to new tests
  selftests: KVM: Use KVM_SET_MP_STATE to power off vCPU in psci_test
  selftests: KVM: Create helper for making SMCCC calls
  selftests: KVM: Rename psci_cpu_on_test to psci_test
  KVM: arm64: Implement PSCI SYSTEM_SUSPEND
  KVM: arm64: Add support for userspace to suspend a vCPU
  KVM: arm64: Return a value from check_vcpu_requests()
  KVM: arm64: Rename the KVM_REQ_SLEEP handler
  KVM: arm64: Track vCPU power state using MP state values
  KVM: arm64: Dedupe vCPU power off helpers
  KVM: arm64: Don't depend on fallthrough to hide SYSTEM_RESET2

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-05-16 17:48:20 +01:00
Marc Zyngier
0586e28aaa Merge branch kvm-arm64/hcall-selection into kvmarm-master/next
* kvm-arm64/hcall-selection:
  : .
  : Introduce a new set of virtual sysregs for userspace to
  : select the hypercalls it wants to see exposed to the guest.
  :
  : Patches courtesy of Raghavendra and Oliver.
  : .
  KVM: arm64: Fix hypercall bitmap writeback when vcpus have already run
  KVM: arm64: Hide KVM_REG_ARM_*_BMAP_BIT_COUNT from userspace
  Documentation: Fix index.rst after psci.rst renaming
  selftests: KVM: aarch64: Add the bitmap firmware registers to get-reg-list
  selftests: KVM: aarch64: Introduce hypercall ABI test
  selftests: KVM: Create helper for making SMCCC calls
  selftests: KVM: Rename psci_cpu_on_test to psci_test
  tools: Import ARM SMCCC definitions
  Docs: KVM: Add doc for the bitmap firmware registers
  Docs: KVM: Rename psci.rst to hypercalls.rst
  KVM: arm64: Add vendor hypervisor firmware register
  KVM: arm64: Add standard hypervisor firmware register
  KVM: arm64: Setup a framework for hypercall bitmap firmware registers
  KVM: arm64: Factor out firmware register handling from psci.c

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-05-16 17:47:03 +01:00
Marc Zyngier
20492a62b9 KVM: arm64: pmu: Restore compilation when HW_PERF_EVENTS isn't selected
Moving kvm_pmu_events into the vcpu (and refering to it) broke the
somewhat unusual case where the kernel has no support for a PMU
at all.

In order to solve this, move things around a bit so that we can
easily avoid refering to the pmu structure outside of PMU-aware
code. As a bonus, pmu.c isn't compiled in when HW_PERF_EVENTS
isn't selected.

Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/202205161814.KQHpOzsJ-lkp@intel.com
2022-05-16 13:42:41 +01:00
Fuad Tabba
84d751a019 KVM: arm64: Pass pmu events to hyp via vcpu
Instead of the host accessing hyp data directly, pass the pmu
events of the current cpu to hyp via the vcpu.

This adds 64 bits (in two fields) to the vcpu that need to be
synced before every vcpu run in nvhe and protected modes.
However, it isolates the hypervisor from the host, which allows
us to use pmu in protected mode in a subsequent patch.

No visible side effects in behavior intended.

Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220510095710.148178-4-tabba@google.com
2022-05-15 11:26:41 +01:00
Alexandru Elisei
f1f0c0cfea KVM: arm64: Don't BUG_ON() if emulated register table is unsorted
To emulate a register access, KVM uses a table of registers sorted by
register encoding to speed up queries using binary search.

When Linux boots, KVM checks that the table is sorted and uses a BUG_ON()
statement to let the user know if it's not. The unfortunate side effect is
that an unsorted sysreg table brings down the whole kernel, not just KVM,
even though the rest of the kernel can function just fine without KVM. To
make matters worse, on machines which lack a serial console, the user is
left pondering why the machine is taking so long to boot.

Improve this situation by returning an error from kvm_arch_init() if the
sysreg tables are not in the correct order. The machine is still very much
usable for the user, with the exception of virtualization, who can now
easily determine what went wrong.

A minor typo has also been corrected in the check_sysreg_table() function.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220428103405.70884-2-alexandru.elisei@arm.com
2022-05-04 17:52:50 +01:00
Marc Zyngier
d25f30fe41 Merge branch kvm-arm64/aarch32-idreg-trap into kvmarm-master/next
* kvm-arm64/aarch32-idreg-trap:
  : .
  : Add trapping/sanitising infrastructure for AArch32 systen registers,
  : allowing more control over what we actually expose (such as the PMU).
  :
  : Patches courtesy of Oliver and Alexandru.
  : .
  KVM: arm64: Fix new instances of 32bit ESRs
  KVM: arm64: Hide AArch32 PMU registers when not available
  KVM: arm64: Start trapping ID registers for 32 bit guests
  KVM: arm64: Plumb cp10 ID traps through the AArch64 sysreg handler
  KVM: arm64: Wire up CP15 feature registers to their AArch64 equivalents
  KVM: arm64: Don't write to Rt unless sys_reg emulation succeeds
  KVM: arm64: Return a bool from emulate_cp()

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-05-04 09:42:45 +01:00
Marc Zyngier
b2c4caf331 Merge branch kvm-arm64/wfxt into kvmarm-master/next
* kvm-arm64/wfxt:
  : .
  : Add support for the WFET/WFIT instructions that provide the same
  : service as WFE/WFI, only with a timeout.
  : .
  KVM: arm64: Expose the WFXT feature to guests
  KVM: arm64: Offer early resume for non-blocking WFxT instructions
  KVM: arm64: Handle blocking WFIT instruction
  KVM: arm64: Introduce kvm_counter_compute_delta() helper
  KVM: arm64: Simplify kvm_cpu_has_pending_timer()
  arm64: Use WFxT for __delay() when possible
  arm64: Add wfet()/wfit() helpers
  arm64: Add HWCAP advertising FEAT_WFXT
  arm64: Add RV and RN fields for ESR_ELx_WFx_ISS
  arm64: Expand ESR_ELx_WFx_ISS_TI to match its ARMv8.7 definition

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-05-04 09:42:16 +01:00
Oliver Upton
bfbab44568 KVM: arm64: Implement PSCI SYSTEM_SUSPEND
ARM DEN0022D.b 5.19 "SYSTEM_SUSPEND" describes a PSCI call that allows
software to request that a system be placed in the deepest possible
low-power state. Effectively, software can use this to suspend itself to
RAM.

Unfortunately, there really is no good way to implement a system-wide
PSCI call in KVM. Any precondition checks done in the kernel will need
to be repeated by userspace since there is no good way to protect a
critical section that spans an exit to userspace. SYSTEM_RESET and
SYSTEM_OFF are equally plagued by this issue, although no users have
seemingly cared for the relatively long time these calls have been
supported.

The solution is to just make the whole implementation userspace's
problem. Introduce a new system event, KVM_SYSTEM_EVENT_SUSPEND, that
indicates to userspace a calling vCPU has invoked PSCI SYSTEM_SUSPEND.
Additionally, add a CAP to get buy-in from userspace for this new exit
type.

Only advertise the SYSTEM_SUSPEND PSCI call if userspace has opted in.
If a vCPU calls SYSTEM_SUSPEND, punt straight to userspace. Provide
explicit documentation of userspace's responsibilites for the exit and
point to the PSCI specification to describe the actual PSCI call.

Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220504032446.4133305-8-oupton@google.com
2022-05-04 09:28:45 +01:00
Oliver Upton
7b33a09d03 KVM: arm64: Add support for userspace to suspend a vCPU
Introduce a new MP state, KVM_MP_STATE_SUSPENDED, which indicates a vCPU
is in a suspended state. In the suspended state the vCPU will block
until a wakeup event (pending interrupt) is recognized.

Add a new system event type, KVM_SYSTEM_EVENT_WAKEUP, to indicate to
userspace that KVM has recognized one such wakeup event. It is the
responsibility of userspace to then make the vCPU runnable, or leave it
suspended until the next wakeup event.

Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220504032446.4133305-7-oupton@google.com
2022-05-04 09:28:45 +01:00
Oliver Upton
b171f9bbb1 KVM: arm64: Track vCPU power state using MP state values
A subsequent change to KVM will add support for additional power states.
Store the MP state by value rather than keeping track of it as a
boolean.

No functional change intended.

Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220504032446.4133305-4-oupton@google.com
2022-05-04 09:28:44 +01:00
Oliver Upton
1e5794295c KVM: arm64: Dedupe vCPU power off helpers
vcpu_power_off() and kvm_psci_vcpu_off() are equivalent; rename the
former and replace all callsites to the latter.

No functional change intended.

Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220504032446.4133305-3-oupton@google.com
2022-05-04 09:28:44 +01:00
Raghavendra Rao Ananta
b22216e1a6 KVM: arm64: Add vendor hypervisor firmware register
Introduce the firmware register to hold the vendor specific
hypervisor service calls (owner value 6) as a bitmap. The
bitmap represents the features that'll be enabled for the
guest, as configured by the user-space. Currently, this
includes support for KVM-vendor features along with
reading the UID, represented by bit-0, and Precision Time
Protocol (PTP), represented by bit-1.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
[maz: tidy-up bitmap values]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220502233853.1233742-5-rananta@google.com
2022-05-03 21:30:19 +01:00
Raghavendra Rao Ananta
428fd6788d KVM: arm64: Add standard hypervisor firmware register
Introduce the firmware register to hold the standard hypervisor
service calls (owner value 5) as a bitmap. The bitmap represents
the features that'll be enabled for the guest, as configured by
the user-space. Currently, this includes support only for
Paravirtualized time, represented by bit-0.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
[maz: tidy-up bitmap values]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220502233853.1233742-4-rananta@google.com
2022-05-03 21:30:19 +01:00
Raghavendra Rao Ananta
05714cab7d KVM: arm64: Setup a framework for hypercall bitmap firmware registers
KVM regularly introduces new hypercall services to the guests without
any consent from the userspace. This means, the guests can observe
hypercall services in and out as they migrate across various host
kernel versions. This could be a major problem if the guest
discovered a hypercall, started using it, and after getting migrated
to an older kernel realizes that it's no longer available. Depending
on how the guest handles the change, there's a potential chance that
the guest would just panic.

As a result, there's a need for the userspace to elect the services
that it wishes the guest to discover. It can elect these services
based on the kernels spread across its (migration) fleet. To remedy
this, extend the existing firmware pseudo-registers, such as
KVM_REG_ARM_PSCI_VERSION, but by creating a new COPROC register space
for all the hypercall services available.

These firmware registers are categorized based on the service call
owners, but unlike the existing firmware pseudo-registers, they hold
the features supported in the form of a bitmap.

During the VM initialization, the registers are set to upper-limit of
the features supported by the corresponding registers. It's expected
that the VMMs discover the features provided by each register via
GET_ONE_REG, and write back the desired values using SET_ONE_REG.
KVM allows this modification only until the VM has started.

Some of the standard features are not mapped to any bits of the
registers. But since they can recreate the original problem of
making it available without userspace's consent, they need to
be explicitly added to the case-list in
kvm_hvc_call_default_allowed(). Any function-id that's not enabled
via the bitmap, or not listed in kvm_hvc_call_default_allowed, will
be returned as SMCCC_RET_NOT_SUPPORTED to the guest.

Older userspace code can simply ignore the feature and the
hypercall services will be exposed unconditionally to the guests,
thus ensuring backward compatibility.

In this patch, the framework adds the register only for ARM's standard
secure services (owner value 4). Currently, this includes support only
for ARM True Random Number Generator (TRNG) service, with bit-0 of the
register representing mandatory features of v1.0. Other services are
momentarily added in the upcoming patches.

Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
[maz: reduced the scope of some helpers, tidy-up bitmap max values,
 dropped error-only fast path]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220502233853.1233742-3-rananta@google.com
2022-05-03 21:30:19 +01:00
Oliver Upton
9369bc5c5e KVM: arm64: Plumb cp10 ID traps through the AArch64 sysreg handler
In order to enable HCR_EL2.TID3 for AArch32 guests KVM needs to handle
traps where ESR_EL2.EC=0x8, which corresponds to an attempted VMRS
access from an ID group register. Specifically, the MVFR{0-2} registers
are accessed this way from AArch32. Conveniently, these registers are
architecturally mapped to MVFR{0-2}_EL1 in AArch64. Furthermore, KVM
already handles reads to these aliases in AArch64.

Plumb VMRS read traps through to the general AArch64 system register
handler.

Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220503060205.2823727-5-oupton@google.com
2022-05-03 11:14:34 +01:00
Sean Christopherson
f502cc568d KVM: Add max_vcpus field in common 'struct kvm'
For TDX guests, the maximum number of vcpus needs to be specified when the
TDX guest VM is initialized (creating the TDX data corresponding to TDX
guest) before creating vcpu.  It needs to record the maximum number of
vcpus on VM creation (KVM_CREATE_VM) and return error if the number of
vcpus exceeds it

Because there is already max_vcpu member in arm64 struct kvm_arch, move it
to common struct kvm and initialize it to KVM_MAX_VCPUS before
kvm_arch_init_vm() instead of adding it to x86 struct kvm_arch.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Message-Id: <e53234cdee6a92357d06c80c03d77c19cdefb804.1646422845.git.isaku.yamahata@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-05-02 11:42:42 -04:00
Alexandru Elisei
0b12620fdd KVM: arm64: Treat ESR_EL2 as a 64-bit register
ESR_EL2 was defined as a 32-bit register in the initial release of the
ARM Architecture Manual for Armv8-A, and was later extended to 64 bits,
with bits [63:32] RES0. ARMv8.7 introduced FEAT_LS64, which makes use of
bits [36:32].

KVM treats ESR_EL1 as a 64-bit register when saving and restoring the
guest context, but ESR_EL2 is handled as a 32-bit register. Start
treating ESR_EL2 as a 64-bit register to allow KVM to make use of the
most significant 32 bits in the future.

The type chosen to represent ESR_EL2 is u64, as that is consistent with the
notation KVM overwhelmingly uses today (u32), and how the rest of the
registers are declared.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220425114444.368693-5-alexandru.elisei@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-04-29 19:26:27 +01:00
Mark Brown
861262ab86 KVM: arm64: Handle SME host state when running guests
While we don't currently support SME in guests we do currently support it
for the host system so we need to take care of SME's impact, including
the floating point register state, when running guests. Simiarly to SVE
we need to manage the traps in CPACR_RL1, what is new is the handling of
streaming mode and ZA.

Normally we defer any handling of the floating point register state until
the guest first uses it however if the system is in streaming mode FPSIMD
and SVE operations may generate SME traps which we would need to distinguish
from actual attempts by the guest to use SME. Rather than do this for the
time being if we are in streaming mode when entering the guest we force
the floating point state to be saved immediately and exit streaming mode,
meaning that the guest won't generate SME traps for supported operations.

We could handle ZA in the access trap similarly to the FPSIMD/SVE state
without the disruption caused by streaming mode but for simplicity
handle it the same way as streaming mode for now.

This will be revisited when we support SME for guests (hopefully before SME
hardware becomes available), for now it will only incur additional cost on
systems with SME and even there only if streaming mode or ZA are enabled.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419112247.711548-27-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-04-22 18:51:23 +01:00
Mark Brown
0033cd9339 arm64/sme: Implement ZA context switching
Allocate space for storing ZA on first access to SME and use that to save
and restore ZA state when context switching. We do this by using the vector
form of the LDR and STR ZA instructions, these do not require streaming
mode and have implementation recommendations that they avoid contention
issues in shared SMCU implementations.

Since ZA is architecturally guaranteed to be zeroed when enabled we do not
need to explicitly zero ZA, either we will be restoring from a saved copy
or trapping on first use of SME so we know that ZA must be disabled.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-16-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-04-22 18:51:02 +01:00
Marc Zyngier
89f5074c50 KVM: arm64: Handle blocking WFIT instruction
When trapping a blocking WFIT instruction, take it into account when
computing the deadline of the background timer.

The state is tracked with a new vcpu flag, and is gated by a new
CPU capability, which isn't currently enabled.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419182755.601427-6-maz@kernel.org
2022-04-20 13:24:45 +01:00
Reiji Watanabe
26bf74bd9f KVM: arm64: mixed-width check should be skipped for uninitialized vCPUs
KVM allows userspace to configure either all EL1 32bit or 64bit vCPUs
for a guest.  At vCPU reset, vcpu_allowed_register_width() checks
if the vcpu's register width is consistent with all other vCPUs'.
Since the checking is done even against vCPUs that are not initialized
(KVM_ARM_VCPU_INIT has not been done) yet, the uninitialized vCPUs
are erroneously treated as 64bit vCPU, which causes the function to
incorrectly detect a mixed-width VM.

Introduce KVM_ARCH_FLAG_EL1_32BIT and KVM_ARCH_FLAG_REG_WIDTH_CONFIGURED
bits for kvm->arch.flags.  A value of the EL1_32BIT bit indicates that
the guest needs to be configured with all 32bit or 64bit vCPUs, and
a value of the REG_WIDTH_CONFIGURED bit indicates if a value of the
EL1_32BIT bit is valid (already set up). Values in those bits are set at
the first KVM_ARM_VCPU_INIT for the guest based on KVM_ARM_VCPU_EL1_32BIT
configuration for the vCPU.

Check vcpu's register width against those new bits at the vcpu's
KVM_ARM_VCPU_INIT (instead of against other vCPUs' register width).

Fixes: 66e94d5caf ("KVM: arm64: Prevent mixed-width VM creation")
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220329031924.619453-2-reijiw@google.com
2022-04-06 12:29:45 +01:00
Linus Torvalds
1ebdbeb03e ARM:
- Proper emulation of the OSLock feature of the debug architecture
 
 - Scalibility improvements for the MMU lock when dirty logging is on
 
 - New VMID allocator, which will eventually help with SVA in VMs
 
 - Better support for PMUs in heterogenous systems
 
 - PSCI 1.1 support, enabling support for SYSTEM_RESET2
 
 - Implement CONFIG_DEBUG_LIST at EL2
 
 - Make CONFIG_ARM64_ERRATUM_2077057 default y
 
 - Reduce the overhead of VM exit when no interrupt is pending
 
 - Remove traces of 32bit ARM host support from the documentation
 
 - Updated vgic selftests
 
 - Various cleanups, doc updates and spelling fixes
 
 RISC-V:
 
 - Prevent KVM_COMPAT from being selected
 
 - Optimize __kvm_riscv_switch_to() implementation
 
 - RISC-V SBI v0.3 support
 
 s390:
 
 - memop selftest
 
 - fix SCK locking
 
 - adapter interruptions virtualization for secure guests
 
 - add Claudio Imbrenda as maintainer
 
 - first step to do proper storage key checking
 
 x86:
 
 - Continue switching kvm_x86_ops to static_call(); introduce
   static_call_cond() and __static_call_ret0 when applicable.
 
 - Cleanup unused arguments in several functions
 
 - Synthesize AMD 0x80000021 leaf
 
 - Fixes and optimization for Hyper-V sparse-bank hypercalls
 
 - Implement Hyper-V's enlightened MSR bitmap for nested SVM
 
 - Remove MMU auditing
 
 - Eager splitting of page tables (new aka "TDP" MMU only) when dirty
   page tracking is enabled
 
 - Cleanup the implementation of the guest PGD cache
 
 - Preparation for the implementation of Intel IPI virtualization
 
 - Fix some segment descriptor checks in the emulator
 
 - Allow AMD AVIC support on systems with physical APIC ID above 255
 
 - Better API to disable virtualization quirks
 
 - Fixes and optimizations for the zapping of page tables:
 
   - Zap roots in two passes, avoiding RCU read-side critical sections
     that last too long for very large guests backed by 4 KiB SPTEs.
 
   - Zap invalid and defunct roots asynchronously via concurrency-managed
     work queue.
 
   - Allowing yielding when zapping TDP MMU roots in response to the root's
     last reference being put.
 
   - Batch more TLB flushes with an RCU trick.  Whoever frees the paging
     structure now holds RCU as a proxy for all vCPUs running in the guest,
     i.e. to prolongs the grace period on their behalf.  It then kicks the
     the vCPUs out of guest mode before doing rcu_read_unlock().
 
 Generic:
 
 - Introduce __vcalloc and use it for very large allocations that
   need memcg accounting
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:
   - Proper emulation of the OSLock feature of the debug architecture

   - Scalibility improvements for the MMU lock when dirty logging is on

   - New VMID allocator, which will eventually help with SVA in VMs

   - Better support for PMUs in heterogenous systems

   - PSCI 1.1 support, enabling support for SYSTEM_RESET2

   - Implement CONFIG_DEBUG_LIST at EL2

   - Make CONFIG_ARM64_ERRATUM_2077057 default y

   - Reduce the overhead of VM exit when no interrupt is pending

   - Remove traces of 32bit ARM host support from the documentation

   - Updated vgic selftests

   - Various cleanups, doc updates and spelling fixes

  RISC-V:
   - Prevent KVM_COMPAT from being selected

   - Optimize __kvm_riscv_switch_to() implementation

   - RISC-V SBI v0.3 support

  s390:
   - memop selftest

   - fix SCK locking

   - adapter interruptions virtualization for secure guests

   - add Claudio Imbrenda as maintainer

   - first step to do proper storage key checking

  x86:
   - Continue switching kvm_x86_ops to static_call(); introduce
     static_call_cond() and __static_call_ret0 when applicable.

   - Cleanup unused arguments in several functions

   - Synthesize AMD 0x80000021 leaf

   - Fixes and optimization for Hyper-V sparse-bank hypercalls

   - Implement Hyper-V's enlightened MSR bitmap for nested SVM

   - Remove MMU auditing

   - Eager splitting of page tables (new aka "TDP" MMU only) when dirty
     page tracking is enabled

   - Cleanup the implementation of the guest PGD cache

   - Preparation for the implementation of Intel IPI virtualization

   - Fix some segment descriptor checks in the emulator

   - Allow AMD AVIC support on systems with physical APIC ID above 255

   - Better API to disable virtualization quirks

   - Fixes and optimizations for the zapping of page tables:

      - Zap roots in two passes, avoiding RCU read-side critical
        sections that last too long for very large guests backed by 4
        KiB SPTEs.

      - Zap invalid and defunct roots asynchronously via
        concurrency-managed work queue.

      - Allowing yielding when zapping TDP MMU roots in response to the
        root's last reference being put.

      - Batch more TLB flushes with an RCU trick. Whoever frees the
        paging structure now holds RCU as a proxy for all vCPUs running
        in the guest, i.e. to prolongs the grace period on their behalf.
        It then kicks the the vCPUs out of guest mode before doing
        rcu_read_unlock().

  Generic:
   - Introduce __vcalloc and use it for very large allocations that need
     memcg accounting"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits)
  KVM: use kvcalloc for array allocations
  KVM: x86: Introduce KVM_CAP_DISABLE_QUIRKS2
  kvm: x86: Require const tsc for RT
  KVM: x86: synthesize CPUID leaf 0x80000021h if useful
  KVM: x86: add support for CPUID leaf 0x80000021
  KVM: x86: do not use KVM_X86_OP_OPTIONAL_RET0 for get_mt_mask
  Revert "KVM: x86/mmu: Zap only TDP MMU leafs in kvm_zap_gfn_range()"
  kvm: x86/mmu: Flush TLB before zap_gfn_range releases RCU
  KVM: arm64: fix typos in comments
  KVM: arm64: Generalise VM features into a set of flags
  KVM: s390: selftests: Add error memop tests
  KVM: s390: selftests: Add more copy memop tests
  KVM: s390: selftests: Add named stages for memop test
  KVM: s390: selftests: Add macro as abstraction for MEM_OP
  KVM: s390: selftests: Split memop tests
  KVM: s390x: fix SCK locking
  RISC-V: KVM: Implement SBI HSM suspend call
  RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() function
  RISC-V: Add SBI HSM suspend related defines
  RISC-V: KVM: Implement SBI v0.3 SRST extension
  ...
2022-03-24 11:58:57 -07:00
Marc Zyngier
06394531b4 KVM: arm64: Generalise VM features into a set of flags
We currently deal with a set of booleans for VM features,
while they could be better represented as set of flags
contained in an unsigned long, similarily to what we are
doing on the CPU side.

Signed-off-by: Marc Zyngier <maz@kernel.org>
[Oliver: Flag-ify the 'ran_once' boolean]
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220311174001.605719-2-oupton@google.com
2022-03-18 14:02:33 +00:00
James Morse
5bdf343760 KVM: arm64: Allow indirect vectors to be used without SPECTRE_V3A
CPUs vulnerable to Spectre-BHB either need to make an SMC-CC firmware
call from the vectors, or run a sequence of branches. This gets added
to the hyp vectors. If there is no support for arch-workaround-1 in
firmware, the indirect vector will be used.

kvm_init_vector_slots() only initialises the two indirect slots if
the platform is vulnerable to Spectre-v3a. pKVM's hyp_map_vectors()
only initialises __hyp_bp_vect_base if the platform is vulnerable to
Spectre-v3a.

As there are about to more users of the indirect vectors, ensure
their entries in hyp_spectre_vector_selector[] are always initialised,
and __hyp_bp_vect_base defaults to the regular VA mapping.

The Spectre-v3a check is moved to a helper
kvm_system_needs_idmapped_vectors(), and merged with the code
that creates the hyp mappings.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
2022-02-15 17:38:25 +00:00
Marc Zyngier
00e6dae00e Merge branch kvm-arm64/pmu-bl into kvmarm-master/next
* kvm-arm64/pmu-bl:
  : .
  : Improve PMU support on heterogeneous systems, courtesy of Alexandru Elisei
  : .
  KVM: arm64: Refuse to run VCPU if the PMU doesn't match the physical CPU
  KVM: arm64: Add KVM_ARM_VCPU_PMU_V3_SET_PMU attribute
  KVM: arm64: Keep a list of probed PMUs
  KVM: arm64: Keep a per-VM pointer to the default PMU
  perf: Fix wrong name in comment for struct perf_cpu_context
  KVM: arm64: Do not change the PMU event filter after a VCPU has run

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-02-08 17:54:41 +00:00
Alexandru Elisei
583cda1b0e KVM: arm64: Refuse to run VCPU if the PMU doesn't match the physical CPU
Userspace can assign a PMU to a VCPU with the KVM_ARM_VCPU_PMU_V3_SET_PMU
device ioctl. If the VCPU is scheduled on a physical CPU which has a
different PMU, the perf events needed to emulate a guest PMU won't be
scheduled in and the guest performance counters will stop counting. Treat
it as an userspace error and refuse to run the VCPU in this situation.

Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220127161759.53553-7-alexandru.elisei@arm.com
2022-02-08 17:51:22 +00:00
Marc Zyngier
46b1878214 KVM: arm64: Keep a per-VM pointer to the default PMU
As we are about to allow selection of the PMU exposed to a guest, start by
keeping track of the default one instead of only the PMU version.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20220127161759.53553-4-alexandru.elisei@arm.com
2022-02-08 17:51:21 +00:00
Marc Zyngier
5177fe91e4 KVM: arm64: Do not change the PMU event filter after a VCPU has run
Userspace can specify which events a guest is allowed to use with the
KVM_ARM_VCPU_PMU_V3_FILTER attribute. The list of allowed events can be
identified by a guest from reading the PMCEID{0,1}_EL0 registers.

Changing the PMU event filter after a VCPU has run can cause reads of the
registers performed before the filter is changed to return different values
than reads performed with the new event filter in place. The architecture
defines the two registers as read-only, and this behaviour contradicts
that.

Keep track when the first VCPU has run and deny changes to the PMU event
filter to prevent this from happening.

Signed-off-by: Marc Zyngier <maz@kernel.org>
[ Alexandru E: Added commit message, updated ioctl documentation ]
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220127161759.53553-2-alexandru.elisei@arm.com
2022-02-08 17:51:21 +00:00
Marc Zyngier
ebca68972e Merge branch kvm-arm64/vmid-allocator into kvmarm-master/next
* kvm-arm64/vmid-allocator:
  : .
  : VMID allocation rewrite from Shameerali Kolothum Thodi, paving the
  : way for pinned VMIDs and SVA.
  : .
  KVM: arm64: Make active_vmids invalid on vCPU schedule out
  KVM: arm64: Align the VMID allocation with the arm64 ASID
  KVM: arm64: Make VMID bits accessible outside of allocator
  KVM: arm64: Introduce a new VMID allocator for KVM

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-02-08 14:58:38 +00:00
Shameer Kolothum
100b4f092f KVM: arm64: Make active_vmids invalid on vCPU schedule out
Like ASID allocator, we copy the active_vmids into the
reserved_vmids on a rollover. But it's unlikely that
every CPU will have a vCPU as current task and we may
end up unnecessarily reserving the VMID space.

Hence, set active_vmids to an invalid one when scheduling
out a vCPU.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211122121844.867-5-shameerali.kolothum.thodi@huawei.com
2022-02-08 14:57:04 +00:00
Julien Grall
3248136b36 KVM: arm64: Align the VMID allocation with the arm64 ASID
At the moment, the VMID algorithm will send an SGI to all the
CPUs to force an exit and then broadcast a full TLB flush and
I-Cache invalidation.

This patch uses the new VMID allocator. The benefits are:
   - Aligns with arm64 ASID algorithm.
   - CPUs are not forced to exit at roll-over. Instead,
     the VMID will be marked reserved and context invalidation
     is broadcasted. This will reduce the IPIs traffic.
   - More flexible to add support for pinned KVM VMIDs in
     the future.
   
With the new algo, the code is now adapted:
    - The call to update_vmid() will be done with preemption
      disabled as the new algo requires to store information
      per-CPU.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211122121844.867-4-shameerali.kolothum.thodi@huawei.com
2022-02-08 14:57:03 +00:00
Shameer Kolothum
f8051e9609 KVM: arm64: Make VMID bits accessible outside of allocator
Since we already set the kvm_arm_vmid_bits in the VMID allocator
init function, make it accessible outside as well so that it can
be used in the subsequent patch.

Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211122121844.867-3-shameerali.kolothum.thodi@huawei.com
2022-02-08 14:46:28 +00:00
Shameer Kolothum
417838392f KVM: arm64: Introduce a new VMID allocator for KVM
A new VMID allocator for arm64 KVM use. This is based on
arm64 ASID allocator algorithm.

One major deviation from the ASID allocator is the way we
flush the context. Unlike ASID allocator, we expect less
frequent rollover in the case of VMIDs. Hence, instead of
marking the CPU as flush_pending and issuing a local context
invalidation on the next context switch, we  broadcast TLB
flush + I-cache invalidation over the inner shareable domain
on rollover.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211122121844.867-2-shameerali.kolothum.thodi@huawei.com
2022-02-08 14:46:28 +00:00
Marc Zyngier
2bb48074b3 Merge branch kvm-arm64/mmu-rwlock into kvmarm-master/next
* kvm-arm64/mmu-rwlock:
  : .
  : MMU locking optimisations from Jing Zhang, allowing permission
  : relaxations to occur in parallel.
  : .
  KVM: selftests: Add vgic initialization for dirty log perf test for ARM
  KVM: arm64: Add fast path to handle permission relaxation during dirty logging
  KVM: arm64: Use read/write spin lock for MMU protection

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-02-08 14:29:29 +00:00
Jing Zhang
fcc5bf8963 KVM: arm64: Use read/write spin lock for MMU protection
Replace MMU spinlock with rwlock and update all instances of the lock
being acquired with a write lock acquisition.
Future commit will add a fast path for permission relaxation during
dirty logging under a read lock.

Signed-off-by: Jing Zhang <jingzhangos@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220118015703.3630552-2-jingzhangos@google.com
2022-02-08 14:27:52 +00:00
Oliver Upton
7dabf02f43 KVM: arm64: Emulate the OS Lock
The OS lock blocks all debug exceptions at every EL. To date, KVM has
not implemented the OS lock for its guests, despite the fact that it is
mandatory per the architecture. Simple context switching between the
guest and host is not appropriate, as its effects are not constrained to
the guest context.

Emulate the OS Lock by clearing MDE and SS in MDSCR_EL1, thereby
blocking all but software breakpoint instructions.

Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220203174159.2887882-5-oupton@google.com
2022-02-08 14:23:41 +00:00
Oliver Upton
d42e26716d KVM: arm64: Stash OSLSR_EL1 in the cpu context
An upcoming change to KVM will emulate the OS Lock from the PoV of the
guest. Add OSLSR_EL1 to the cpu context and handle reads using the
stored value. Define some mnemonics for for handling the OSLM field and
use them to make the reset value of OSLSR_EL1 more readable.

Wire up a custom handler for writes from userspace and prevent any of
the invariant bits from changing. Note that the OSLK bit is not
invariant and will be made writable by the aforementioned change.

Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220203174159.2887882-3-oupton@google.com
2022-02-08 14:23:41 +00:00
Linus Torvalds
79e06c4c49 RISCV:
- Use common KVM implementation of MMU memory caches
 
 - SBI v0.2 support for Guest
 
 - Initial KVM selftests support
 
 - Fix to avoid spurious virtual interrupts after clearing hideleg CSR
 
 - Update email address for Anup and Atish
 
 ARM:
 - Simplification of the 'vcpu first run' by integrating it into
   KVM's 'pid change' flow
 
 - Refactoring of the FP and SVE state tracking, also leading to
   a simpler state and less shared data between EL1 and EL2 in
   the nVHE case
 
 - Tidy up the header file usage for the nvhe hyp object
 
 - New HYP unsharing mechanism, finally allowing pages to be
   unmapped from the Stage-1 EL2 page-tables
 
 - Various pKVM cleanups around refcounting and sharing
 
 - A couple of vgic fixes for bugs that would trigger once
   the vcpu xarray rework is merged, but not sooner
 
 - Add minimal support for ARMv8.7's PMU extension
 
 - Rework kvm_pgtable initialisation ahead of the NV work
 
 - New selftest for IRQ injection
 
 - Teach selftests about the lack of default IPA space and
   page sizes
 
 - Expand sysreg selftest to deal with Pointer Authentication
 
 - The usual bunch of cleanups and doc update
 
 s390:
 - fix sigp sense/start/stop/inconsistency
 
 - cleanups
 
 x86:
 - Clean up some function prototypes more
 
 - improved gfn_to_pfn_cache with proper invalidation, used by Xen emulation
 
 - add KVM_IRQ_ROUTING_XEN_EVTCHN and event channel delivery
 
 - completely remove potential TOC/TOU races in nested SVM consistency checks
 
 - update some PMCs on emulated instructions
 
 - Intel AMX support (joint work between Thomas and Intel)
 
 - large MMU cleanups
 
 - module parameter to disable PMU virtualization
 
 - cleanup register cache
 
 - first part of halt handling cleanups
 
 - Hyper-V enlightened MSR bitmap support for nested hypervisors
 
 Generic:
 - clean up Makefiles
 
 - introduce CONFIG_HAVE_KVM_DIRTY_RING
 
 - optimize memslot lookup using a tree
 
 - optimize vCPU array usage by converting to xarray
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "RISCV:

   - Use common KVM implementation of MMU memory caches

   - SBI v0.2 support for Guest

   - Initial KVM selftests support

   - Fix to avoid spurious virtual interrupts after clearing hideleg CSR

   - Update email address for Anup and Atish

  ARM:

   - Simplification of the 'vcpu first run' by integrating it into KVM's
     'pid change' flow

   - Refactoring of the FP and SVE state tracking, also leading to a
     simpler state and less shared data between EL1 and EL2 in the nVHE
     case

   - Tidy up the header file usage for the nvhe hyp object

   - New HYP unsharing mechanism, finally allowing pages to be unmapped
     from the Stage-1 EL2 page-tables

   - Various pKVM cleanups around refcounting and sharing

   - A couple of vgic fixes for bugs that would trigger once the vcpu
     xarray rework is merged, but not sooner

   - Add minimal support for ARMv8.7's PMU extension

   - Rework kvm_pgtable initialisation ahead of the NV work

   - New selftest for IRQ injection

   - Teach selftests about the lack of default IPA space and page sizes

   - Expand sysreg selftest to deal with Pointer Authentication

   - The usual bunch of cleanups and doc update

  s390:

   - fix sigp sense/start/stop/inconsistency

   - cleanups

  x86:

   - Clean up some function prototypes more

   - improved gfn_to_pfn_cache with proper invalidation, used by Xen
     emulation

   - add KVM_IRQ_ROUTING_XEN_EVTCHN and event channel delivery

   - completely remove potential TOC/TOU races in nested SVM consistency
     checks

   - update some PMCs on emulated instructions

   - Intel AMX support (joint work between Thomas and Intel)

   - large MMU cleanups

   - module parameter to disable PMU virtualization

   - cleanup register cache

   - first part of halt handling cleanups

   - Hyper-V enlightened MSR bitmap support for nested hypervisors

  Generic:

   - clean up Makefiles

   - introduce CONFIG_HAVE_KVM_DIRTY_RING

   - optimize memslot lookup using a tree

   - optimize vCPU array usage by converting to xarray"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (268 commits)
  x86/fpu: Fix inline prefix warnings
  selftest: kvm: Add amx selftest
  selftest: kvm: Move struct kvm_x86_state to header
  selftest: kvm: Reorder vcpu_load_state steps for AMX
  kvm: x86: Disable interception for IA32_XFD on demand
  x86/fpu: Provide fpu_sync_guest_vmexit_xfd_state()
  kvm: selftests: Add support for KVM_CAP_XSAVE2
  kvm: x86: Add support for getting/setting expanded xstate buffer
  x86/fpu: Add uabi_size to guest_fpu
  kvm: x86: Add CPUID support for Intel AMX
  kvm: x86: Add XCR0 support for Intel AMX
  kvm: x86: Disable RDMSR interception of IA32_XFD_ERR
  kvm: x86: Emulate IA32_XFD_ERR for guest
  kvm: x86: Intercept #NM for saving IA32_XFD_ERR
  x86/fpu: Prepare xfd_err in struct fpu_guest
  kvm: x86: Add emulation for IA32_XFD
  x86/fpu: Provide fpu_update_guest_xfd() for IA32_XFD emulation
  kvm: x86: Enable dynamic xfeatures at KVM_SET_CPUID2
  x86/fpu: Provide fpu_enable_guest_xfd_features() for KVM
  x86/fpu: Add guest support to xfd_enable_feature()
  ...
2022-01-16 16:15:14 +02:00
Paolo Bonzini
7fd55a02a4 KVM/arm64 updates for Linux 5.16
- Simplification of the 'vcpu first run' by integrating it into
   KVM's 'pid change' flow
 
 - Refactoring of the FP and SVE state tracking, also leading to
   a simpler state and less shared data between EL1 and EL2 in
   the nVHE case
 
 - Tidy up the header file usage for the nvhe hyp object
 
 - New HYP unsharing mechanism, finally allowing pages to be
   unmapped from the Stage-1 EL2 page-tables
 
 - Various pKVM cleanups around refcounting and sharing
 
 - A couple of vgic fixes for bugs that would trigger once
   the vcpu xarray rework is merged, but not sooner
 
 - Add minimal support for ARMv8.7's PMU extension
 
 - Rework kvm_pgtable initialisation ahead of the NV work
 
 - New selftest for IRQ injection
 
 - Teach selftests about the lack of default IPA space and
   page sizes
 
 - Expand sysreg selftest to deal with Pointer Authentication
 
 - The usual bunch of cleanups and doc update
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Merge tag 'kvmarm-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for Linux 5.16

- Simplification of the 'vcpu first run' by integrating it into
  KVM's 'pid change' flow

- Refactoring of the FP and SVE state tracking, also leading to
  a simpler state and less shared data between EL1 and EL2 in
  the nVHE case

- Tidy up the header file usage for the nvhe hyp object

- New HYP unsharing mechanism, finally allowing pages to be
  unmapped from the Stage-1 EL2 page-tables

- Various pKVM cleanups around refcounting and sharing

- A couple of vgic fixes for bugs that would trigger once
  the vcpu xarray rework is merged, but not sooner

- Add minimal support for ARMv8.7's PMU extension

- Rework kvm_pgtable initialisation ahead of the NV work

- New selftest for IRQ injection

- Teach selftests about the lack of default IPA space and
  page sizes

- Expand sysreg selftest to deal with Pointer Authentication

- The usual bunch of cleanups and doc update
2022-01-07 10:42:19 -05:00
Marc Zyngier
1c53a1ae36 Merge branch kvm-arm64/misc-5.17 into kvmarm-master/next
* kvm-arm64/misc-5.17:
  : .
  : Misc fixes and improvements:
  : - Add minimal support for ARMv8.7's PMU extension
  : - Constify kvm_io_gic_ops
  : - Drop kvm_is_transparent_hugepage() prototype
  : - Drop unused workaround_flags field
  : - Rework kvm_pgtable initialisation
  : - Documentation fixes
  : - Replace open-coded SCTLR_EL1.EE useage with its defined macro
  : - Sysreg list selftest update to handle PAuth
  : - Include cleanups
  : .
  KVM: arm64: vgic: Replace kernel.h with the necessary inclusions
  KVM: arm64: Fix comment typo in kvm_vcpu_finalize_sve()
  KVM: arm64: selftests: get-reg-list: Add pauth configuration
  KVM: arm64: Fix comment on barrier in kvm_psci_vcpu_on()
  KVM: arm64: Fix comment for kvm_reset_vcpu()
  KVM: arm64: Use defined value for SCTLR_ELx_EE
  KVM: arm64: Rework kvm_pgtable initialisation
  KVM: arm64: Drop unused workaround_flags vcpu field

Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-01-04 17:16:15 +00:00
Quentin Perret
52b28657eb KVM: arm64: pkvm: Unshare guest structs during teardown
Make use of the newly introduced unshare hypercall during guest teardown
to unmap guest-related data structures from the hyp stage-1.

Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211215161232.1480836-15-qperret@google.com
2021-12-16 12:58:57 +00:00
Marc Zyngier
142ff9bddb KVM: arm64: Drop unused workaround_flags vcpu field
workaround_flags is a leftover from our earlier Spectre-v4 workaround
implementation, and now serves no purpose.

Get rid of the field and the corresponding asm-offset definition.

Fixes: 29e8910a56 ("KVM: arm64: Simplify handling of ARCH_WORKAROUND_2")
Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-12-08 14:54:07 +00:00
Sean Christopherson
005467e06b KVM: Drop obsolete kvm_arch_vcpu_block_finish()
Drop kvm_arch_vcpu_block_finish() now that all arch implementations are
nops.

No functional change intended.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20211009021236.4122790-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:50 -05:00
Marc Zyngier
2d761dbf7f Merge branch kvm-arm64/fpsimd-tracking into kvmarm-master/next
* kvm-arm64/fpsimd-tracking:
  : .
  : Simplify the handling of both the FP/SIMD and SVE state by
  : removing the need for mapping the thread at EL2, and by
  : dropping the tracking of the host's SVE state which is
  : always invalid by construction.
  : .
  arm64/fpsimd: Document the use of TIF_FOREIGN_FPSTATE by KVM
  KVM: arm64: Stop mapping current thread_info at EL2
  KVM: arm64: Introduce flag shadowing TIF_FOREIGN_FPSTATE
  KVM: arm64: Remove unused __sve_save_state
  KVM: arm64: Get rid of host SVE tracking/saving
  KVM: arm64: Reorder vcpu flag definitions

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-12-01 12:13:44 +00:00
Marc Zyngier
cc5705fb1b KVM: arm64: Drop vcpu->arch.has_run_once for vcpu->pid
With the transition to kvm_arch_vcpu_run_pid_change() to handle
the "run once" activities, it becomes obvious that has_run_once
is now an exact shadow of vcpu->pid.

Replace vcpu->arch.has_run_once with a new vcpu_has_run_once()
helper that directly checks for vcpu->pid, and get rid of the
now unused field.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-12-01 11:51:22 +00:00
Marc Zyngier
052f064d42 KVM: arm64: Move kvm_arch_vcpu_run_pid_change() out of line
Having kvm_arch_vcpu_run_pid_change() inline doesn't bring anything
to the table. Move it next to kvm_vcpu_first_run_init(), which will
be convenient for what is next to come.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-12-01 11:51:21 +00:00
Marc Zyngier
bee14bca73 KVM: arm64: Stop mapping current thread_info at EL2
Now that we can track an equivalent of TIF_FOREIGN_FPSTATE, drop
the mapping of current's thread_info at EL2.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-11-22 16:01:39 +00:00
Marc Zyngier
af9a0e21d8 KVM: arm64: Introduce flag shadowing TIF_FOREIGN_FPSTATE
We currently have to maintain a mapping the thread_info structure
at EL2 in order to be able to check the TIF_FOREIGN_FPSTATE flag.

In order to eventually get rid of this, start with a vcpu flag that
shadows the thread flag on each entry into the hypervisor.

Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-11-22 16:01:39 +00:00
Marc Zyngier
8383741ab2 KVM: arm64: Get rid of host SVE tracking/saving
The SVE host tracking in KVM is pretty involved. It relies on a
set of flags tracking the ownership of the SVE register, as well
as that of the EL0 access.

It is also pretty scary: __hyp_sve_save_host() computes
a thread_struct pointer and obtains a sve_state which gets directly
accessed without further ado, even on nVHE. How can this even work?

The answer to that is that it doesn't, and that this is mostly dead
code. Closer examination shows that on executing a syscall, userspace
loses its SVE state entirely. This is part of the ABI. Another
thing to notice is that although the kernel provides helpers such as
kernel_neon_begin()/end(), they only deal with the FP/NEON state,
and not SVE.

Given that you can only execute a guest as the result of a syscall,
and that the kernel cannot use SVE by itself, it becomes pretty
obvious that there is never any host SVE state to save, and that
this code is only there to increase confusion.

Get rid of the TIF_SVE tracking and host save infrastructure altogether.

Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-11-22 15:30:27 +00:00
Marc Zyngier
892fd259cb KVM: arm64: Reorder vcpu flag definitions
The vcpu arch flags are in an interesting, semi random order.
As I have made the mistake of reusing a flag once, let's rework
this in an order that I find a bit less confusing.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-11-22 15:25:20 +00:00
Sean Christopherson
17ed14eba2 KVM: arm64: Drop perf.c and fold its tiny bits of code into arm.c
Call KVM's (un)register perf callbacks helpers directly from arm.c and
delete perf.c

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20211111020738.2512932-17-seanjc@google.com
2021-11-17 14:49:11 +01:00
Sean Christopherson
e1bfc24577 KVM: Move x86's perf guest info callbacks to generic KVM
Move x86's perf guest callbacks into common KVM, as they are semantically
identical to arm64's callbacks (the only other such KVM callbacks).
arm64 will convert to the common versions in a future patch.

Implement the necessary arm64 arch hooks now to avoid having to provide
stubs or a temporary #define (from x86) to avoid arm64 compilation errors
when CONFIG_GUEST_PERF_EVENTS=y.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211111020738.2512932-13-seanjc@google.com
2021-11-17 14:49:10 +01:00
Sean Christopherson
2934e3d093 perf: Stop pretending that perf can handle multiple guest callbacks
Drop the 'int' return value from the perf (un)register callbacks helpers
and stop pretending perf can support multiple callbacks.  The 'int'
returns are not future proofing anything as none of the callers take
action on an error.  It's also not obvious that there will ever be
co-tenant hypervisors, and if there are, that allowing multiple callbacks
to be registered is desirable or even correct.

Opportunistically rename callbacks=>cbs in the affected declarations to
match their definitions.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20211111020738.2512932-5-seanjc@google.com
2021-11-17 14:49:07 +01:00
Paolo Bonzini
84886c262e KVM/arm64 fixes for 5.16, take #1
- Fix the host S2 finalization by solely iterating over the memblocks
   instead of the whole IPA space
 
 - Tighten the return value of kvm_vcpu_preferred_target() now that
   32bit support is long gone
 
 - Make sure the extraction of ESR_ELx.EC is limited to the architected
   bits
 
 - Comment fixups
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Merge tag 'kvmarm-fixes-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master

KVM/arm64 fixes for 5.16, take #1

- Fix the host S2 finalization by solely iterating over the memblocks
  instead of the whole IPA space

- Tighten the return value of kvm_vcpu_preferred_target() now that
  32bit support is long gone

- Make sure the extraction of ESR_ELx.EC is limited to the architected
  bits

- Comment fixups
2021-11-12 16:01:55 -05:00
YueHaibing
08e873cb70 KVM: arm64: Change the return type of kvm_vcpu_preferred_target()
kvm_vcpu_preferred_target() always return 0 because kvm_target_cpu()
never returns a negative error code.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211105011500.16280-1-yuehaibing@huawei.com
2021-11-08 10:48:47 +00:00
Paolo Bonzini
4e33868433 KVM/arm64 updates for Linux 5.16
- More progress on the protected VM front, now with the full
   fixed feature set as well as the limitation of some hypercalls
   after initialisation.
 
 - Cleanup of the RAZ/WI sysreg handling, which was pointlessly
   complicated
 
 - Fixes for the vgic placement in the IPA space, together with a
   bunch of selftests
 
 - More memcg accounting of the memory allocated on behalf of a guest
 
 - Timer and vgic selftests
 
 - Workarounds for the Apple M1 broken vgic implementation
 
 - KConfig cleanups
 
 - New kvmarm.mode=none option, for those who really dislike us
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Merge tag 'kvmarm-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for Linux 5.16

- More progress on the protected VM front, now with the full
  fixed feature set as well as the limitation of some hypercalls
  after initialisation.

- Cleanup of the RAZ/WI sysreg handling, which was pointlessly
  complicated

- Fixes for the vgic placement in the IPA space, together with a
  bunch of selftests

- More memcg accounting of the memory allocated on behalf of a guest

- Timer and vgic selftests

- Workarounds for the Apple M1 broken vgic implementation

- KConfig cleanups

- New kvmarm.mode=none option, for those who really dislike us
2021-10-31 02:28:48 -04:00
Marc Zyngier
be08c3cf3c Merge branch kvm-arm64/pkvm/fixed-features into kvmarm-master/next
* kvm-arm64/pkvm/fixed-features: (22 commits)
  : .
  : Add the pKVM fixed feature that allows a bunch of exceptions
  : to either be forbidden or be easily handled at EL2.
  : .
  KVM: arm64: pkvm: Give priority to standard traps over pvm handling
  KVM: arm64: pkvm: Pass vpcu instead of kvm to kvm_get_exit_handler_array()
  KVM: arm64: pkvm: Move kvm_handle_pvm_restricted around
  KVM: arm64: pkvm: Consolidate include files
  KVM: arm64: pkvm: Preserve pending SError on exit from AArch32
  KVM: arm64: pkvm: Handle GICv3 traps as required
  KVM: arm64: pkvm: Drop sysregs that should never be routed to the host
  KVM: arm64: pkvm: Drop AArch32-specific registers
  KVM: arm64: pkvm: Make the ERR/ERX*_EL1 registers RAZ/WI
  KVM: arm64: pkvm: Use a single function to expose all id-regs
  KVM: arm64: Fix early exit ptrauth handling
  KVM: arm64: Handle protected guests at 32 bits
  KVM: arm64: Trap access to pVM restricted features
  KVM: arm64: Move sanitized copies of CPU features
  KVM: arm64: Initialize trap registers for protected VMs
  KVM: arm64: Add handlers for protected VM System Registers
  KVM: arm64: Simplify masking out MTE in feature id reg
  KVM: arm64: Add missing field descriptor for MDCR_EL2
  KVM: arm64: Pass struct kvm to per-EC handlers
  KVM: arm64: Move early handlers to per-EC handlers
  ...

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-10-18 17:20:50 +01:00
Fuad Tabba
2a0c343386 KVM: arm64: Initialize trap registers for protected VMs
Protected VMs have more restricted features that need to be
trapped. Moreover, the host should not be trusted to set the
appropriate trapping registers and their values.

Initialize the trapping registers, i.e., hcr_el2, mdcr_el2, and
cptr_el2 at EL2 for protected guests, based on the values of the
guest's feature id registers.

No functional change intended as trap handlers introduced in the
previous patch are still not hooked in to the guest exit
handlers.

Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211010145636.1950948-9-tabba@google.com
2021-10-11 14:57:29 +01:00
Marc Zyngier
b6a68b97af KVM: arm64: Allow KVM to be disabled from the command line
Although KVM can be compiled out of the kernel, it cannot be disabled
at runtime. Allow this possibility by introducing a new mode that
will prevent KVM from initialising.

This is useful in the (limited) circumstances where you don't want
KVM to be available (what is wrong with you?), or when you want
to install another hypervisor instead (good luck with that).

Reviewed-by: David Brazdil <dbrazdil@google.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Andrew Scull <ascull@google.com>
Link: https://lore.kernel.org/r/20211001170553.3062988-1-maz@kernel.org
2021-10-11 09:48:47 +01:00
Juergen Gross
78b497f2e6 kvm: use kvfree() in kvm_arch_free_vm()
By switching from kfree() to kvfree() in kvm_arch_free_vm() Arm64 can
use the common variant. This can be accomplished by adding another
macro __KVM_HAVE_ARCH_VM_FREE, which will be used only by x86 for now.

Further simplification can be achieved by adding __kvm_arch_free_vm()
doing the common part.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Message-Id: <20210903130808.30142-5-jgross@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-01 03:44:57 -04:00
Marc Zyngier
7c7b363d62 Merge branch kvm-arm64/pkvm-fixed-features-prologue into kvmarm-master/next
* kvm-arm64/pkvm-fixed-features-prologue:
  : Rework a bunch of common infrastructure as a prologue
  : to Fuad Tabba's protected VM fixed feature series.
  KVM: arm64: Upgrade trace_kvm_arm_set_dreg32() to 64bit
  KVM: arm64: Add config register bit definitions
  KVM: arm64: Add feature register flag definitions
  KVM: arm64: Track value of cptr_el2 in struct kvm_vcpu_arch
  KVM: arm64: Keep mdcr_el2's value as set by __init_el2_debug
  KVM: arm64: Restore mdcr_el2 from vcpu
  KVM: arm64: Refactor sys_regs.h,c for nVHE reuse
  KVM: arm64: Fix names of config register fields
  KVM: arm64: MDCR_EL2 is a 64-bit register
  KVM: arm64: Remove trailing whitespace in comment
  KVM: arm64: placeholder to check if VM is protected

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20 12:23:53 +01:00
Marc Zyngier
ca3385a507 Merge branch kvm-arm64/generic-entry into kvmarm-master/next
Switch KVM/arm64 to the generic entry code, courtesy of Oliver Upton

* kvm-arm64/generic-entry:
  KVM: arm64: Use generic KVM xfer to guest work function
  entry: KVM: Allow use of generic KVM entry w/o full generic support
  KVM: arm64: Record number of signal exits as a vCPU stat

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20 12:23:09 +01:00
Marc Zyngier
3ce5db8a59 Merge branch kvm-arm64/misc-5.15 into kvmarm-master/next
* kvm-arm64/misc-5.15:
  : Misc improvements for 5.15:
  :
  : - Account the number of VMID-wide TLB invalidations as
  :   remote TLB flushes
  : - Fix comments in the VGIC code
  : - Cleanup the PMU IMPDEF identification
  : - Streamline the TGRAN2 usage
  : - Avoid advertising a 52bit IPA range for non-64KB configs
  : - Avoid spurious signalling when a HW-mapped interrupt is in the
  :   A+P state on entry, and in the P state on exit, but that the
  :   physical line is not pending anymore.
  : - Bunch of minor cleanups
  KVM: arm64: vgic: Resample HW pending state on deactivation
  KVM: arm64: vgic: Drop WARN from vgic_get_irq
  KVM: arm64: Drop unused REQUIRES_VIRT
  KVM: arm64: Drop check_kvm_target_cpu() based percpu probe
  KVM: arm64: Drop init_common_resources()
  KVM: arm64: Use ARM64_MIN_PARANGE_BITS as the minimum supported IPA
  arm64/mm: Add remaining ID_AA64MMFR0_PARANGE_ macros
  KVM: arm64: Restrict IPA size to maximum 48 bits on 4K and 16K page size
  arm64/mm: Define ID_AA64MMFR0_TGRAN_2_SHIFT
  KVM: arm64: perf: Replace '0xf' instances with ID_AA64DFR0_PMUVER_IMP_DEF
  KVM: arm64: Fix comments related to GICv2 PMR reporting
  KVM: arm64: Count VMID-wide TLB invalidations
  arm64/kexec: Test page size support with new TGRAN range values

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-08-20 12:14:56 +01:00
Fuad Tabba
cd496228fd KVM: arm64: Track value of cptr_el2 in struct kvm_vcpu_arch
Track the baseline guest value for cptr_el2 in struct
kvm_vcpu_arch, similar to the other registers that control traps.
Use this value when setting cptr_el2 for the guest.

Currently this value is unchanged (CPTR_EL2_DEFAULT), but future
patches will set trapping bits based on features supported for
the guest.

No functional change intended.

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210817081134.2918285-9-tabba@google.com
2021-08-20 11:12:17 +01:00
Fuad Tabba
1460b4b25f KVM: arm64: Restore mdcr_el2 from vcpu
On deactivating traps, restore the value of mdcr_el2 from the
newly created and preserved host value vcpu context, rather than
directly reading the hardware register.

Up until and including this patch the two values are the same,
i.e., the hardware register and the vcpu one. A future patch will
be changing the value of mdcr_el2 on activating traps, and this
ensures that its value will be restored.

No functional change intended.

Signed-off-by: Fuad Tabba <tabba@google.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210817081134.2918285-7-tabba@google.com
2021-08-20 11:12:17 +01:00
Fuad Tabba
d6c850dd6c KVM: arm64: MDCR_EL2 is a 64-bit register
Fix the places in KVM that treat MDCR_EL2 as a 32-bit register.
More recent features (e.g., FEAT_SPEv1p2) use bits above 31.

No functional change intended.

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210817081134.2918285-4-tabba@google.com
2021-08-20 11:12:17 +01:00
Fuad Tabba
2ea7f65580 KVM: arm64: placeholder to check if VM is protected
Add a function to check whether a VM is protected (under pKVM).
Since the creation of protected VMs isn't enabled yet, this is a
placeholder that always returns false. The intention is for this
to become a check for protected VMs in the future (see Will's RFC).

No functional change intended.

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/kvmarm/20210603183347.1695-1-will@kernel.org/
Link: https://lore.kernel.org/r/20210817081134.2918285-2-tabba@google.com
2021-08-20 11:12:05 +01:00
Oliver Upton
fe5161d2c3 KVM: arm64: Record number of signal exits as a vCPU stat
Most other architectures that implement KVM record a statistic
indicating the number of times a vCPU has exited due to a pending
signal. Add support for that stat to arm64.

Reviewed-by: Jing Zhang <jingzhangos@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210802192809.1851010-2-oupton@google.com
2021-08-19 11:19:41 +01:00
Anshuman Khandual
6b7982fefc KVM: arm64: Drop check_kvm_target_cpu() based percpu probe
kvm_target_cpu() never returns a negative error code, so check_kvm_target()
would never have 'ret' filled with a negative error code. Hence the percpu
probe via check_kvm_target_cpu() does not make sense as its never going to
find an unsupported CPU, forcing kvm_arch_init() to exit early. Hence lets
just drop this percpu probe (and also check_kvm_target_cpu()) altogether.

While here, this also changes kvm_target_cpu() return type to a u32, making
it explicit that an error code will not be returned from this function.

Cc: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: kvmarm@lists.cs.columbia.edu
Cc: linux-kernel@vger.kernel.org
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1628744994-16623-5-git-send-email-anshuman.khandual@arm.com
2021-08-18 09:26:07 +01:00
Marc Zyngier
7a3ba3095a KVM: arm64: Remove PMSWINC_EL0 shadow register
We keep an entry for the PMSWINC_EL0 register in the vcpu structure,
while *never* writing anything there outside of reset.

Given that the register is defined as write-only, that we always
trap when this register is accessed, there is little point in saving
anything anyway.

Get rid of the entry, and save a mighty 8 bytes per vcpu structure.

We still need to keep it exposed to userspace in order to preserve
backward compatibility with previously saved VMs. Since userspace
cannot expect any effect of writing to PMSWINC_EL0, treat the
register as RAZ/WI for the purpose of userspace access.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210719123902.1493805-5-maz@kernel.org
2021-08-02 14:26:34 +01:00
Paolo Bonzini
b8917b4ae4 KVM/arm64 updates for v5.14.
- Add MTE support in guests, complete with tag save/restore interface
 - Reduce the impact of CMOs by moving them in the page-table code
 - Allow device block mappings at stage-2
 - Reduce the footprint of the vmemmap in protected mode
 - Support the vGIC on dumb systems such as the Apple M1
 - Add selftest infrastructure to support multiple configuration
   and apply that to PMU/non-PMU setups
 - Add selftests for the debug architecture
 - The usual crop of PMU fixes
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Merge tag 'kvmarm-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for v5.14.

- Add MTE support in guests, complete with tag save/restore interface
- Reduce the impact of CMOs by moving them in the page-table code
- Allow device block mappings at stage-2
- Reduce the footprint of the vmemmap in protected mode
- Support the vGIC on dumb systems such as the Apple M1
- Add selftest infrastructure to support multiple configuration
  and apply that to PMU/non-PMU setups
- Add selftests for the debug architecture
- The usual crop of PMU fixes
2021-06-25 11:24:24 -04:00
Jing Zhang
0193cc908b KVM: stats: Separate generic stats from architecture specific ones
Generic KVM stats are those collected in architecture independent code
or those supported by all architectures; put all generic statistics in
a separate structure.  This ensures that they are defined the same way
in the statistics API which is being added, removing duplication among
different architectures in the declaration of the descriptors.

No functional change intended.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-2-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-24 11:47:56 -04:00
Marc Zyngier
9f03db6673 Merge branch kvm-arm64/mmu/mte into kvmarm-master/next
KVM/arm64 support for MTE, courtesy of Steven Price.
It allows the guest to use memory tagging, and offers
a new userspace API to save/restore the tags.

* kvm-arm64/mmu/mte:
  KVM: arm64: Document MTE capability and ioctl
  KVM: arm64: Add ioctl to fetch/store tags in a guest
  KVM: arm64: Expose KVM_ARM_CAP_MTE
  KVM: arm64: Save/restore MTE registers
  KVM: arm64: Introduce MTE VM feature
  arm64: mte: Sync tags for pages where PTE is untagged

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-22 15:09:34 +01:00
Steven Price
f0376edb1d KVM: arm64: Add ioctl to fetch/store tags in a guest
The VMM may not wish to have it's own mapping of guest memory mapped
with PROT_MTE because this causes problems if the VMM has tag checking
enabled (the guest controls the tags in physical RAM and it's unlikely
the tags are correct for the VMM).

Instead add a new ioctl which allows the VMM to easily read/write the
tags from guest memory, allowing the VMM's mapping to be non-PROT_MTE
while the VMM can still read/write the tags for the purpose of
migration.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210621111716.37157-6-steven.price@arm.com
2021-06-22 14:08:06 +01:00
Steven Price
e1f358b504 KVM: arm64: Save/restore MTE registers
Define the new system registers that MTE introduces and context switch
them. The MTE feature is still hidden from the ID register as it isn't
supported in a VM yet.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210621111716.37157-4-steven.price@arm.com
2021-06-22 14:08:05 +01:00
Steven Price
ea7fc1bb1c KVM: arm64: Introduce MTE VM feature
Add a new VM feature 'KVM_ARM_CAP_MTE' which enables memory tagging
for a VM. This will expose the feature to the guest and automatically
tag memory pages touched by the VM as PG_mte_tagged (and clear the tag
storage) to ensure that the guest cannot see stale tags, and so that
the tags are correctly saved/restored across swap.

Actually exposing the new capability to user space happens in a later
patch.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
[maz: move VM_SHARED sampling into the critical section]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210621111716.37157-3-steven.price@arm.com
2021-06-22 14:08:05 +01:00
Marc Zyngier
d0c94c4979 KVM: arm64: Restore PMU configuration on first run
Restoring a guest with an active virtual PMU results in no perf
counters being instanciated on the host side. Not quite what
you'd expect from a restore.

In order to fix this, force a writeback of PMCR_EL0 on the first
run of a vcpu (using a new request so that it happens once the
vcpu has been loaded). This will in turn create all the host-side
counters that were missing.

Reported-by: Jinank Jain <jinankj@amazon.de>
Tested-by: Jinank Jain <jinankj@amazon.de>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/87wnrbylxv.wl-maz@kernel.org
Link: https://lore.kernel.org/r/b53dfcf9bbc4db7f96154b1cd5188d72b9766358.camel@amazon.de
2021-06-18 14:18:37 +01:00