Oliver reports that the kvm_has_feat() helper is not behaviing as
expected for negative feature. On investigation, the main issue
seems to be caused by the following construct:
#define get_idreg_field(kvm, id, fld) \
(id##_##fld##_SIGNED ? \
get_idreg_field_signed(kvm, id, fld) : \
get_idreg_field_unsigned(kvm, id, fld))
where one side of the expression evaluates as something signed,
and the other as something unsigned. In retrospect, this is totally
braindead, as the compiler converts this into an unsigned expression.
When compared to something that is 0, the test is simply elided.
Epic fail. Similar issue exists in the expand_field_sign() macro.
The correct way to handle this is to chose between signed and unsigned
comparisons, so that both sides of the ternary expression are of the
same type (bool).
In order to keep the code readable (sort of), we introduce new
comparison primitives taking an operator as a parameter, and
rewrite the kvm_has_feat*() helpers in terms of these primitives.
Fixes: c62d7a23b9 ("KVM: arm64: Add feature checking helpers")
Reported-by: Oliver Upton <oliver.upton@linux.dev>
Tested-by: Oliver Upton <oliver.upton@linux.dev>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20241002204239.2051637-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
* New Stage-2 page table dumper, reusing the main ptdump infrastructure
* FP8 support
* Nested virtualization now supports the address translation (FEAT_ATS1A)
family of instructions
* Add selftest checks for a bunch of timer emulation corner cases
* Fix multiple cases where KVM/arm64 doesn't correctly handle the guest
trying to use a GICv3 that wasn't advertised
* Remove REG_HIDDEN_USER from the sysreg infrastructure, making
things little simpler
* Prevent MTE tags being restored by userspace if we are actively
logging writes, as that's a recipe for disaster
* Correct the refcount on a page that is not considered for MTE tag
copying (such as a device)
* When walking a page table to split block mappings, synchronize only
at the end the walk rather than on every store
* Fix boundary check when transfering memory using FFA
* Fix pKVM TLB invalidation, only affecting currently out of tree
code but worth addressing for peace of mind
LoongArch:
* Revert qspinlock to test-and-set simple lock on VM.
* Add Loongson Binary Translation extension support.
* Add PMU support for guest.
* Enable paravirt feature control from VMM.
* Implement function kvm_para_has_feature().
RISC-V:
* Fix sbiret init before forwarding to userspace
* Don't zero-out PMU snapshot area before freeing data
* Allow legacy PMU access from guest
* Fix to allow hpmcounter31 from the guest
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Merge tag 'for-linus-non-x86' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
"These are the non-x86 changes (mostly ARM, as is usually the case).
The generic and x86 changes will come later"
ARM:
- New Stage-2 page table dumper, reusing the main ptdump
infrastructure
- FP8 support
- Nested virtualization now supports the address translation
(FEAT_ATS1A) family of instructions
- Add selftest checks for a bunch of timer emulation corner cases
- Fix multiple cases where KVM/arm64 doesn't correctly handle the
guest trying to use a GICv3 that wasn't advertised
- Remove REG_HIDDEN_USER from the sysreg infrastructure, making
things little simpler
- Prevent MTE tags being restored by userspace if we are actively
logging writes, as that's a recipe for disaster
- Correct the refcount on a page that is not considered for MTE tag
copying (such as a device)
- When walking a page table to split block mappings, synchronize only
at the end the walk rather than on every store
- Fix boundary check when transfering memory using FFA
- Fix pKVM TLB invalidation, only affecting currently out of tree
code but worth addressing for peace of mind
LoongArch:
- Revert qspinlock to test-and-set simple lock on VM.
- Add Loongson Binary Translation extension support.
- Add PMU support for guest.
- Enable paravirt feature control from VMM.
- Implement function kvm_para_has_feature().
RISC-V:
- Fix sbiret init before forwarding to userspace
- Don't zero-out PMU snapshot area before freeing data
- Allow legacy PMU access from guest
- Fix to allow hpmcounter31 from the guest"
* tag 'for-linus-non-x86' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (64 commits)
LoongArch: KVM: Implement function kvm_para_has_feature()
LoongArch: KVM: Enable paravirt feature control from VMM
LoongArch: KVM: Add PMU support for guest
KVM: arm64: Get rid of REG_HIDDEN_USER visibility qualifier
KVM: arm64: Simplify visibility handling of AArch32 SPSR_*
KVM: arm64: Simplify handling of CNTKCTL_EL12
LoongArch: KVM: Add vm migration support for LBT registers
LoongArch: KVM: Add Binary Translation extension support
LoongArch: KVM: Add VM feature detection function
LoongArch: Revert qspinlock to test-and-set simple lock on VM
KVM: arm64: Register ptdump with debugfs on guest creation
arm64: ptdump: Don't override the level when operating on the stage-2 tables
arm64: ptdump: Use the ptdump description from a local context
arm64: ptdump: Expose the attribute parsing functionality
KVM: arm64: Add memory length checks and remove inline in do_ffa_mem_xfer
KVM: arm64: Move pagetable definitions to common header
KVM: arm64: nv: Add support for FEAT_ATS1A
KVM: arm64: nv: Plumb handling of AT S1* traps from EL2
KVM: arm64: nv: Make AT+PAN instructions aware of FEAT_PAN3
KVM: arm64: nv: Sanitise SCTLR_EL1.EPAN according to VM configuration
...
* for-next/poe: (31 commits)
arm64: pkeys: remove redundant WARN
kselftest/arm64: Add test case for POR_EL0 signal frame records
kselftest/arm64: parse POE_MAGIC in a signal frame
kselftest/arm64: add HWCAP test for FEAT_S1POE
selftests: mm: make protection_keys test work on arm64
selftests: mm: move fpregs printing
kselftest/arm64: move get_header()
arm64: add Permission Overlay Extension Kconfig
arm64: enable PKEY support for CPUs with S1POE
arm64: enable POE and PIE to coexist
arm64/ptrace: add support for FEAT_POE
arm64: add POE signal support
arm64: implement PKEYS support
arm64: add pte_access_permitted_no_overlay()
arm64: handle PKEY/POE faults
arm64: mask out POIndex when modifying a PTE
arm64: convert protection key into vm_flags and pgprot values
arm64: add POIndex defines
arm64: re-order MTE VM_ flags
arm64: enable the Permission Overlay Extension for EL0
...
* kvm-arm64/vgic-sre-traps:
: .
: Fix the multiple of cases where KVM/arm64 doesn't correctly
: handle the guest trying to use a GICv3 that isn't advertised.
:
: From the cover letter:
:
: "It recently appeared that, when running on a GICv3-equipped platform
: (which is what non-ancient arm64 HW has), *not* configuring a GICv3
: for the guest could result in less than desirable outcomes.
:
: We have multiple issues to fix:
:
: - for registers that *always* trap (the SGI registers) or that *may*
: trap (the SRE register), we need to check whether a GICv3 has been
: instantiated before acting upon the trap.
:
: - for registers that only conditionally trap, we must actively trap
: them even in the absence of a GICv3 being instantiated, and handle
: those traps accordingly.
:
: - finally, ID registers must reflect the absence of a GICv3, so that
: we are consistent.
:
: This series goes through all these requirements. The main complexity
: here is to apply a GICv3 configuration on the host in the absence of a
: GICv3 in the guest. This is pretty hackish, but I don't have a much
: better solution so far.
:
: As part of making wider use of of the trap bits, we fully define the
: trap routing as per the architecture, something that we eventually
: need for NV anyway."
: .
KVM: arm64: selftests: Cope with lack of GICv3 in set_id_regs
KVM: arm64: Add selftest checking how the absence of GICv3 is handled
KVM: arm64: Unify UNDEF injection helpers
KVM: arm64: Make most GICv3 accesses UNDEF if they trap
KVM: arm64: Honor guest requested traps in GICv3 emulation
KVM: arm64: Add trap routing information for ICH_HCR_EL2
KVM: arm64: Add ICH_HCR_EL2 to the vcpu state
KVM: arm64: Zero ID_AA64PFR0_EL1.GIC when no GICv3 is presented to the guest
KVM: arm64: Add helper for last ditch idreg adjustments
KVM: arm64: Force GICv3 trap activation when no irqchip is configured on VHE
KVM: arm64: Force SRE traps when SRE access is not enabled
KVM: arm64: Move GICv3 trap configuration to kvm_calculate_traps()
Signed-off-by: Marc Zyngier <maz@kernel.org>
Define the new system registers that POE introduces and context switch them.
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240822151113.1479789-8-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
As we are about to describe the trap routing for ICH_HCR_EL2, add
the register to the vcpu state in its VNCR form, as well as reset
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240827152517.3909653-7-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Just like the rest of the FP/SIMD state, FPMR needs to be context
switched.
The only interesting thing here is that we need to treat the pKVM
part a bit differently, as the host FP state is never written back
to the vcpu thread, but instead stored locally and eagerly restored.
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240820131802.3547589-5-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Just like SVCR, FPMR is currently stored at the wrong location.
Let's move it where it belongs.
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240820131802.3547589-4-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
As we are about to check for the advertisement of FPMR support to
a guest in a number of places, add a predicate that will gate most
of the support code for FPMR.
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240820131802.3547589-3-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
SVCR is just a system register, and has no purpose being outside
of the sysreg array. If anything, it only makes it more difficult
to eventually support SME one day. If ever.
Move it into the array with its little friends, and associate it
with a visibility predicate.
Although this is dead code, it at least paves the way for the
next set of FP-related extensions.
Reviewed-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240820131802.3547589-2-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Various PMUv3 registers which are a mask of counters are 64-bit
registers, but the accessor functions take a u32. This has been fine as
the upper 32-bits have been RES0 as there has been a maximum of 32
counters prior to Armv9.4/8.9. With Armv9.4/8.9, a 33rd counter is
added. Update the accessor functions to use a u64 instead.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Tested-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20240731-arm-pmu-3-9-icntr-v3-2-280a8d7ff465@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
- Enable halt poll shrinking by default, as Intel found it to be a clear win.
- Setup empty IRQ routing when creating a VM to avoid having to synchronize
SRCU when creating a split IRQCHIP on x86.
- Rework the sched_in/out() paths to replace kvm_arch_sched_in() with a flag
that arch code can use for hooking both sched_in() and sched_out().
- Take the vCPU @id as an "unsigned long" instead of "u32" to avoid
truncating a bogus value from userspace, e.g. to help userspace detect bugs.
- Mark a vCPU as preempted if and only if it's scheduled out while in the
KVM_RUN loop, e.g. to avoid marking it preempted and thus writing guest
memory when retrieving guest state during live migration blackout.
- A few minor cleanups
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Merge tag 'kvm-x86-generic-6.11' of https://github.com/kvm-x86/linux into HEAD
KVM generic changes for 6.11
- Enable halt poll shrinking by default, as Intel found it to be a clear win.
- Setup empty IRQ routing when creating a VM to avoid having to synchronize
SRCU when creating a split IRQCHIP on x86.
- Rework the sched_in/out() paths to replace kvm_arch_sched_in() with a flag
that arch code can use for hooking both sched_in() and sched_out().
- Take the vCPU @id as an "unsigned long" instead of "u32" to avoid
truncating a bogus value from userspace, e.g. to help userspace detect bugs.
- Mark a vCPU as preempted if and only if it's scheduled out while in the
KVM_RUN loop, e.g. to avoid marking it preempted and thus writing guest
memory when retrieving guest state during live migration blackout.
- A few minor cleanups
* kvm-arm64/nv-sve:
: CPTR_EL2, FPSIMD/SVE support for nested
:
: This series brings support for honoring the guest hypervisor's CPTR_EL2
: trap configuration when running a nested guest, along with support for
: FPSIMD/SVE usage at L1 and L2.
KVM: arm64: Allow the use of SVE+NV
KVM: arm64: nv: Add additional trap setup for CPTR_EL2
KVM: arm64: nv: Add trap description for CPTR_EL2
KVM: arm64: nv: Add TCPAC/TTA to CPTR->CPACR conversion helper
KVM: arm64: nv: Honor guest hypervisor's FP/SVE traps in CPTR_EL2
KVM: arm64: nv: Load guest FP state for ZCR_EL2 trap
KVM: arm64: nv: Handle CPACR_EL1 traps
KVM: arm64: Spin off helper for programming CPTR traps
KVM: arm64: nv: Ensure correct VL is loaded before saving SVE state
KVM: arm64: nv: Use guest hypervisor's max VL when running nested guest
KVM: arm64: nv: Save guest's ZCR_EL2 when in hyp context
KVM: arm64: nv: Load guest hyp's ZCR into EL1 state
KVM: arm64: nv: Handle ZCR_EL2 traps
KVM: arm64: nv: Forward SVE traps to guest hypervisor
KVM: arm64: nv: Forward FP/ASIMD traps to guest hypervisor
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
* kvm-arm64/ctr-el0:
: Support for user changes to CTR_EL0, courtesy of Sebastian Ott
:
: Allow userspace to change the guest-visible value of CTR_EL0 for a VM,
: so long as the requested value represents a subset of features supported
: by hardware. In other words, prevent the VMM from over-promising the
: capabilities of hardware.
:
: Make this happen by fitting CTR_EL0 into the existing infrastructure for
: feature ID registers.
KVM: selftests: Assert that MPIDR_EL1 is unchanged across vCPU reset
KVM: arm64: nv: Unfudge ID_AA64PFR0_EL1 masking
KVM: selftests: arm64: Test writes to CTR_EL0
KVM: arm64: rename functions for invariant sys regs
KVM: arm64: show writable masks for feature registers
KVM: arm64: Treat CTR_EL0 as a VM feature ID register
KVM: arm64: unify code to prepare traps
KVM: arm64: nv: Use accessors for modifying ID registers
KVM: arm64: Add helper for writing ID regs
KVM: arm64: Use read-only helper for reading VM ID registers
KVM: arm64: Make idregs debugfs iterator search sysreg table directly
KVM: arm64: Get sys_reg encoding from descriptor in idregs_debug_show()
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Load the guest hypervisor's ZCR_EL2 into the corresponding EL1 register
when restoring SVE state, as ZCR_EL2 affects the VL in the hypervisor
context.
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240620164653.1130714-5-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Unlike other SVE-related registers, ZCR_EL2 takes a sysreg trap to EL2
when HCR_EL2.NV = 1. KVM still needs to honor the guest hypervisor's
trap configuration, which expects an SVE trap (i.e. ESR_EL2.EC = 0x19)
when CPTR traps are enabled for the vCPU's current context.
Otherwise, if the guest hypervisor has traps disabled, emulate the
access by mapping the requested VL into ZCR_EL1.
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240620164653.1130714-4-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
CTR_EL0 is currently handled as an invariant register, thus
guests will be presented with the host value of that register.
Add emulation for CTR_EL0 based on a per VM value. Userspace can
switch off DIC and IDC bits and reduce DminLine and IminLine sizes.
Naturally, ensure CTR_EL0 is trapped (HCR_EL2.TID2=1) any time that a
VM's CTR_EL0 differs from hardware.
Signed-off-by: Sebastian Ott <sebott@redhat.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Link: https://lore.kernel.org/r/20240619174036.483943-8-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
There are 2 functions to calculate traps via HCR_EL2:
* kvm_init_sysreg() called via KVM_RUN (before the 1st run or when
the pid changes)
* vcpu_reset_hcr() called via KVM_ARM_VCPU_INIT
To unify these 2 and to support traps that are dependent on the
ID register configuration, move the code from vcpu_reset_hcr()
to sys_regs.c and call it via kvm_init_sysreg().
We still have to keep the non-FWB handling stuff in vcpu_reset_hcr().
Also the initialization with HCR_GUEST_FLAGS is kept there but guarded
by !vcpu_has_run_once() to ensure that previous calculated values
don't get overwritten.
While at it rename kvm_init_sysreg() to kvm_calculate_traps() to
better reflect what it's doing.
Signed-off-by: Sebastian Ott <sebott@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240619174036.483943-7-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
In the interest of abstracting away the underlying storage of feature
ID registers, rework the nested code to go through the accessors instead
of directly iterating the id_regs array.
This means we now lose the property that ID registers unknown to the
nested code get zeroed, but we really ought to be handling those
explicitly going forward.
Link: https://lore.kernel.org/r/20240619174036.483943-6-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Replace the remaining usage of IDREG() with a new helper for setting the
value of a feature ID register, with the benefit of cramming in some
extra sanity checks.
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Link: https://lore.kernel.org/r/20240619174036.483943-5-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
IDREG() expands to the storage of a particular ID reg, which can be
useful for handling both reads and writes. However, outside of a select
few situations, the ID registers should be considered read only.
Replace current readers with a new macro that expands to the value of
the field rather than the field itself.
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Link: https://lore.kernel.org/r/20240619174036.483943-4-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Add Stage-2 mmu data structures for virtual EL2 and for nested guests.
We don't yet populate shadow Stage-2 page tables, but we now have a
framework for getting to a shadow Stage-2 pgd.
We allocate twice the number of vcpus as Stage-2 mmu structures because
that's sufficient for each vcpu running two translation regimes without
having to flush the Stage-2 page tables.
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/20240614144552.2773592-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Delete kvm_arch_sched_in() now that all implementations are nops.
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Acked-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/r/20240522014013.1672962-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Now that we have introduced finalize_init_hyp_mode(), lets
consolidate the initializing of the host_data fpsimd_state and
sve state.
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240603122852.3923848-8-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Protected mode needs to maintain (save/restore) the host's sve
state, rather than relying on the host kernel to do that. This is
to avoid leaking information to the host about guests and the
type of operations they are performing.
As a first step towards that, allocate memory mapped at hyp, per
cpu, for the host sve state. The following patch will use this
memory to save/restore the host state.
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20240603122852.3923848-6-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
* kvm-arm64/mpidr-reset:
: .
: Fixes for CLIDR_EL1 and MPIDR_EL1 being accidentally mutable across
: a vcpu reset, courtesy of Oliver. From the cover letter:
:
: "For VM-wide feature ID registers we ensure they get initialized once for
: the lifetime of a VM. On the other hand, vCPU-local feature ID registers
: get re-initialized on every vCPU reset, potentially clobbering the
: values userspace set up.
:
: MPIDR_EL1 and CLIDR_EL1 are the only registers in this space that we
: allow userspace to modify for now. Clobbering the value of MPIDR_EL1 has
: some disastrous side effects as the compressed index used by the
: MPIDR-to-vCPU lookup table assumes MPIDR_EL1 is immutable after KVM_RUN.
:
: Series + reproducer test case to address the problem of KVM wiping out
: userspace changes to these registers. Note that there are still some
: differences between VM and vCPU scoped feature ID registers from the
: perspective of userspace. We do not allow the value of VM-scope
: registers to change after KVM_RUN, but vCPU registers remain mutable."
: .
KVM: selftests: arm64: Test vCPU-scoped feature ID registers
KVM: selftests: arm64: Test that feature ID regs survive a reset
KVM: selftests: arm64: Store expected register value in set_id_regs
KVM: selftests: arm64: Rename helper in set_id_regs to imply VM scope
KVM: arm64: Only reset vCPU-scoped feature ID regs once
KVM: arm64: Reset VM feature ID regs from kvm_reset_sys_regs()
KVM: arm64: Rename is_id_reg() to imply VM scope
Signed-off-by: Marc Zyngier <maz@kernel.org>
The general expecation with feature ID registers is that they're 'reset'
exactly once by KVM for the lifetime of a vCPU/VM, such that any
userspace changes to the CPU features / identity are honored after a
vCPU gets reset (e.g. PSCI_ON).
KVM handles what it calls VM-scoped feature ID registers correctly, but
feature ID registers local to a vCPU (CLIDR_EL1, MPIDR_EL1) get wiped
after every reset. What's especially concerning is that a
potentially-changing MPIDR_EL1 breaks MPIDR compression for indexing
mpidr_data, as the mask of useful bits to build the index could change.
This is absolutely no good. Avoid resetting vCPU feature ID registers
more than once.
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240502233529.1958459-4-oliver.upton@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>
* kvm-arm64/misc-6.10:
: .
: Misc fixes and updates targeting 6.10
:
: - Improve boot-time diagnostics when the sysreg tables
: are not correctly sorted
:
: - Allow FFA_MSG_SEND_DIRECT_REQ in the FFA proxy
:
: - Fix duplicate XNX field in the ID_AA64MMFR1_EL1
: writeable mask
:
: - Allocate PPIs and SGIs outside of the vcpu structure, allowing
: for smaller EL2 mapping and some flexibility in implementing
: more or less than 32 private IRQs.
:
: - Use bitmap_gather() instead of its open-coded equivalent
:
: - Make protected mode use hVHE if available
:
: - Purge stale mpidr_data if a vcpu is created after the MPIDR
: map has been created
: .
KVM: arm64: Destroy mpidr_data for 'late' vCPU creation
KVM: arm64: Use hVHE in pKVM by default on CPUs with VHE support
KVM: arm64: Fix hvhe/nvhe early alias parsing
KVM: arm64: Convert kvm_mpidr_index() to bitmap_gather()
KVM: arm64: vgic: Allocate private interrupts on demand
KVM: arm64: Remove duplicated AA64MMFR1_EL1 XNX
KVM: arm64: Remove FFA_MSG_SEND_DIRECT_REQ from the denylist
KVM: arm64: Improve out-of-order sysreg table diagnostics
Signed-off-by: Marc Zyngier <maz@kernel.org>
* kvm-arm64/pkvm-6.10: (25 commits)
: .
: At last, a bunch of pKVM patches, courtesy of Fuad Tabba.
: From the cover letter:
:
: "This series is a bit of a bombay-mix of patches we've been
: carrying. There's no one overarching theme, but they do improve
: the code by fixing existing bugs in pKVM, refactoring code to
: make it more readable and easier to re-use for pKVM, or adding
: functionality to the existing pKVM code upstream."
: .
KVM: arm64: Force injection of a data abort on NISV MMIO exit
KVM: arm64: Restrict supported capabilities for protected VMs
KVM: arm64: Refactor setting the return value in kvm_vm_ioctl_enable_cap()
KVM: arm64: Document the KVM/arm64-specific calls in hypercalls.rst
KVM: arm64: Rename firmware pseudo-register documentation file
KVM: arm64: Reformat/beautify PTP hypercall documentation
KVM: arm64: Clarify rationale for ZCR_EL1 value restored on guest exit
KVM: arm64: Introduce and use predicates that check for protected VMs
KVM: arm64: Add is_pkvm_initialized() helper
KVM: arm64: Simplify vgic-v3 hypercalls
KVM: arm64: Move setting the page as dirty out of the critical section
KVM: arm64: Change kvm_handle_mmio_return() return polarity
KVM: arm64: Fix comment for __pkvm_vcpu_init_traps()
KVM: arm64: Prevent kmemleak from accessing .hyp.data
KVM: arm64: Do not map the host fpsimd state to hyp in pKVM
KVM: arm64: Rename __tlb_switch_to_{guest,host}() in VHE
KVM: arm64: Support TLB invalidation in guest context
KVM: arm64: Avoid BBM when changing only s/w bits in Stage-2 PTE
KVM: arm64: Check for PTE validity when checking for executable/cacheable
KVM: arm64: Avoid BUG-ing from the host abort path
...
Signed-off-by: Marc Zyngier <maz@kernel.org>
* kvm-arm64/nv-eret-pauth:
: .
: Add NV support for the ERETAA/ERETAB instructions. From the cover letter:
:
: "Although the current upstream NV support has *some* support for
: correctly emulating ERET, that support is only partial as it doesn't
: support the ERETAA and ERETAB variants.
:
: Supporting these instructions was cast aside for a long time as it
: involves implementing some form of PAuth emulation, something I wasn't
: overly keen on. But I have reached a point where enough of the
: infrastructure is there that it actually makes sense. So here it is!"
: .
KVM: arm64: nv: Work around lack of pauth support in old toolchains
KVM: arm64: Drop trapping of PAuth instructions/keys
KVM: arm64: nv: Advertise support for PAuth
KVM: arm64: nv: Handle ERETA[AB] instructions
KVM: arm64: nv: Add emulation for ERETAx instructions
KVM: arm64: nv: Add kvm_has_pauth() helper
KVM: arm64: nv: Reinject PAC exceptions caused by HCR_EL2.API==0
KVM: arm64: nv: Handle HCR_EL2.{API,APK} independently
KVM: arm64: nv: Honor HFGITR_EL2.ERET being set
KVM: arm64: nv: Fast-track 'InHost' exception returns
KVM: arm64: nv: Add trap forwarding for ERET and SMC
KVM: arm64: nv: Configure HCR_EL2 for FEAT_NV2
KVM: arm64: nv: Drop VCPU_HYP_CONTEXT flag
KVM: arm64: Constraint PAuth support to consistent implementations
KVM: arm64: Add helpers for ESR_ELx_ERET_ISS_ERET*
KVM: arm64: Harden __ctxt_sys_reg() against out-of-range values
Signed-off-by: Marc Zyngier <maz@kernel.org>
Linux 6.9 has introduced new bitmap manipulation helpers, with
bitmap_gather() being of special interest, as it does exactly
what kvm_mpidr_index() is already doing.
Make the latter a wrapper around the former.
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240502154247.3012042-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
In order to determine whether or not a VM or vcpu are protected,
introduce helpers to query this state. While at it, use the vcpu
helper to check vcpus protected state instead of the kvm one.
Co-authored-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240423150538.2103045-19-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
pKVM maintains its own state at EL2 for tracking the host fpsimd
state. Therefore, no need to map and share the host's view with
it.
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240423150538.2103045-12-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
To avoid direct comparison against the fp_owner enum, add a new
function that performs the check, host_owns_fp_regs(), to
complement the existing guest_owns_fp_regs().
To check for fpsimd state ownership, use the helpers instead of
directly using the enums.
No functional change intended.
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240423150538.2103045-4-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
guest_owns_fp_regs() will be used to check fpsimd state ownership
across kvm/arm64. Therefore, move it to kvm_host.h to widen its
scope.
Moreover, the host state is not per-vcpu anymore, the vcpu
parameter isn't used, so remove it as well.
No functional change intended.
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240423150538.2103045-3-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Pointer Authentication comes in many flavors, and a faithful emulation
relies on correctly handling the flavour implemented by the HW.
For this, provide a new kvm_has_pauth() that checks whether we
expose to the guest a particular level of support. This checks
across all 3 possible authentication algorithms (Q5, Q3 and IMPDEF).
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240419102935.1935571-12-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
It has become obvious that HCR_EL2.NV serves the exact same use
as VCPU_HYP_CONTEXT, only in an architectural way. So just drop
the flag for good.
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240419102935.1935571-5-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
The unsuspecting kernel tinkerer can be easily confused into
writing something that looks like this:
ikey.lo = __vcpu_sys_reg(vcpu, SYS_APIAKEYLO_EL1);
which seems vaguely sensible, until you realise that the second
parameter is the encoding of a sysreg, and not the index into
the vcpu sysreg file... Debugging what happens in this case is
an interesting exercise in head<->wall interactions.
As they often say: "Any resemblance to actual persons, living
or dead, or actual events is purely coincidental".
In order to save people's time, add some compile-time hardening
that will at least weed out the "stupidly out of range" values.
This will *not* catch anything that isn't a compile-time constant.
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240419102935.1935571-2-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
In retrospect, it is fairly obvious that the FP state ownership
is only meaningful for a given CPU, and that locating this
information in the vcpu was just a mistake.
Move the ownership tracking into the host data structure, and
rename it from fp_state to fp_owner, which is a better description
(name suggested by Mark Brown).
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
As the name of the field indicates, host_fpsimd_state is strictly
a host piece of data, and we reset this pointer on each PID change.
So let's move it where it belongs, and set it at load-time. Although
this is slightly more often, it is a well defined life-cycle which
matches other pieces of data.
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
As for the rest of the host debug state, the host copy of mdcr_el2
has little to do in the vcpu, and is better placed in the host_data
structure.
Reviewed-by : Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Keeping host_debug_state on a per-vcpu basis is completely
pointless. The lifetime of this data is only that of the inner
run-loop, which means it is never accessed outside of the core
EL2 code.
Move the structure into kvm_host_data, and save over 500 bytes
per vcpu.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
In order to facilitate the introduction of new per-CPU state,
add a new host_data_ptr() helped that hides some of the per-CPU
verbosity, and make it easier to move that state around in the
future.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
* Changes to FPU handling came in via the main s390 pull request
* Only deliver to the guest the SCLP events that userspace has
requested.
* More virtual vs physical address fixes (only a cleanup since
virtual and physical address spaces are currently the same).
* Fix selftests undefined behavior.
x86:
* Fix a restriction that the guest can't program a PMU event whose
encoding matches an architectural event that isn't included in the
guest CPUID. The enumeration of an architectural event only says
that if a CPU supports an architectural event, then the event can be
programmed *using the architectural encoding*. The enumeration does
NOT say anything about the encoding when the CPU doesn't report support
the event *in general*. It might support it, and it might support it
using the same encoding that made it into the architectural PMU spec.
* Fix a variety of bugs in KVM's emulation of RDPMC (more details on
individual commits) and add a selftest to verify KVM correctly emulates
RDMPC, counter availability, and a variety of other PMC-related
behaviors that depend on guest CPUID and therefore are easier to
validate with selftests than with custom guests (aka kvm-unit-tests).
* Zero out PMU state on AMD if the virtual PMU is disabled, it does not
cause any bug but it wastes time in various cases where KVM would check
if a PMC event needs to be synthesized.
* Optimize triggering of emulated events, with a nice ~10% performance
improvement in VM-Exit microbenchmarks when a vPMU is exposed to the
guest.
* Tighten the check for "PMI in guest" to reduce false positives if an NMI
arrives in the host while KVM is handling an IRQ VM-Exit.
* Fix a bug where KVM would report stale/bogus exit qualification information
when exiting to userspace with an internal error exit code.
* Add a VMX flag in /proc/cpuinfo to report 5-level EPT support.
* Rework TDP MMU root unload, free, and alloc to run with mmu_lock held for
read, e.g. to avoid serializing vCPUs when userspace deletes a memslot.
* Tear down TDP MMU page tables at 4KiB granularity (used to be 1GiB). KVM
doesn't support yielding in the middle of processing a zap, and 1GiB
granularity resulted in multi-millisecond lags that are quite impolite
for CONFIG_PREEMPT kernels.
* Allocate write-tracking metadata on-demand to avoid the memory overhead when
a kernel is built with i915 virtualization support but the workloads use
neither shadow paging nor i915 virtualization.
* Explicitly initialize a variety of on-stack variables in the emulator that
triggered KMSAN false positives.
* Fix the debugregs ABI for 32-bit KVM.
* Rework the "force immediate exit" code so that vendor code ultimately decides
how and when to force the exit, which allowed some optimization for both
Intel and AMD.
* Fix a long-standing bug where kvm_has_noapic_vcpu could be left elevated if
vCPU creation ultimately failed, causing extra unnecessary work.
* Cleanup the logic for checking if the currently loaded vCPU is in-kernel.
* Harden against underflowing the active mmu_notifier invalidation
count, so that "bad" invalidations (usually due to bugs elsehwere in the
kernel) are detected earlier and are less likely to hang the kernel.
x86 Xen emulation:
* Overlay pages can now be cached based on host virtual address,
instead of guest physical addresses. This removes the need to
reconfigure and invalidate the cache if the guest changes the
gpa but the underlying host virtual address remains the same.
* When possible, use a single host TSC value when computing the deadline for
Xen timers in order to improve the accuracy of the timer emulation.
* Inject pending upcall events when the vCPU software-enables its APIC to fix
a bug where an upcall can be lost (and to follow Xen's behavior).
* Fall back to the slow path instead of warning if "fast" IRQ delivery of Xen
events fails, e.g. if the guest has aliased xAPIC IDs.
RISC-V:
* Support exception and interrupt handling in selftests
* New self test for RISC-V architectural timer (Sstc extension)
* New extension support (Ztso, Zacas)
* Support userspace emulation of random number seed CSRs.
ARM:
* Infrastructure for building KVM's trap configuration based on the
architectural features (or lack thereof) advertised in the VM's ID
registers
* Support for mapping vfio-pci BARs as Normal-NC (vaguely similar to
x86's WC) at stage-2, improving the performance of interacting with
assigned devices that can tolerate it
* Conversion of KVM's representation of LPIs to an xarray, utilized to
address serialization some of the serialization on the LPI injection
path
* Support for _architectural_ VHE-only systems, advertised through the
absence of FEAT_E2H0 in the CPU's ID register
* Miscellaneous cleanups, fixes, and spelling corrections to KVM and
selftests
LoongArch:
* Set reserved bits as zero in CPUCFG.
* Start SW timer only when vcpu is blocking.
* Do not restart SW timer when it is expired.
* Remove unnecessary CSR register saving during enter guest.
* Misc cleanups and fixes as usual.
Generic:
* cleanup Kconfig by removing CONFIG_HAVE_KVM, which was basically always
true on all architectures except MIPS (where Kconfig determines the
available depending on CPU capabilities). It is replaced either by
an architecture-dependent symbol for MIPS, and IS_ENABLED(CONFIG_KVM)
everywhere else.
* Factor common "select" statements in common code instead of requiring
each architecture to specify it
* Remove thoroughly obsolete APIs from the uapi headers.
* Move architecture-dependent stuff to uapi/asm/kvm.h
* Always flush the async page fault workqueue when a work item is being
removed, especially during vCPU destruction, to ensure that there are no
workers running in KVM code when all references to KVM-the-module are gone,
i.e. to prevent a very unlikely use-after-free if kvm.ko is unloaded.
* Grab a reference to the VM's mm_struct in the async #PF worker itself instead
of gifting the worker a reference, so that there's no need to remember
to *conditionally* clean up after the worker.
Selftests:
* Reduce boilerplate especially when utilize selftest TAP infrastructure.
* Add basic smoke tests for SEV and SEV-ES, along with a pile of library
support for handling private/encrypted/protected memory.
* Fix benign bugs where tests neglect to close() guest_memfd files.
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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:
- Changes to FPU handling came in via the main s390 pull request
- Only deliver to the guest the SCLP events that userspace has
requested
- More virtual vs physical address fixes (only a cleanup since
virtual and physical address spaces are currently the same)
- Fix selftests undefined behavior
x86:
- Fix a restriction that the guest can't program a PMU event whose
encoding matches an architectural event that isn't included in the
guest CPUID. The enumeration of an architectural event only says
that if a CPU supports an architectural event, then the event can
be programmed *using the architectural encoding*. The enumeration
does NOT say anything about the encoding when the CPU doesn't
report support the event *in general*. It might support it, and it
might support it using the same encoding that made it into the
architectural PMU spec
- Fix a variety of bugs in KVM's emulation of RDPMC (more details on
individual commits) and add a selftest to verify KVM correctly
emulates RDMPC, counter availability, and a variety of other
PMC-related behaviors that depend on guest CPUID and therefore are
easier to validate with selftests than with custom guests (aka
kvm-unit-tests)
- Zero out PMU state on AMD if the virtual PMU is disabled, it does
not cause any bug but it wastes time in various cases where KVM
would check if a PMC event needs to be synthesized
- Optimize triggering of emulated events, with a nice ~10%
performance improvement in VM-Exit microbenchmarks when a vPMU is
exposed to the guest
- Tighten the check for "PMI in guest" to reduce false positives if
an NMI arrives in the host while KVM is handling an IRQ VM-Exit
- Fix a bug where KVM would report stale/bogus exit qualification
information when exiting to userspace with an internal error exit
code
- Add a VMX flag in /proc/cpuinfo to report 5-level EPT support
- Rework TDP MMU root unload, free, and alloc to run with mmu_lock
held for read, e.g. to avoid serializing vCPUs when userspace
deletes a memslot
- Tear down TDP MMU page tables at 4KiB granularity (used to be
1GiB). KVM doesn't support yielding in the middle of processing a
zap, and 1GiB granularity resulted in multi-millisecond lags that
are quite impolite for CONFIG_PREEMPT kernels
- Allocate write-tracking metadata on-demand to avoid the memory
overhead when a kernel is built with i915 virtualization support
but the workloads use neither shadow paging nor i915 virtualization
- Explicitly initialize a variety of on-stack variables in the
emulator that triggered KMSAN false positives
- Fix the debugregs ABI for 32-bit KVM
- Rework the "force immediate exit" code so that vendor code
ultimately decides how and when to force the exit, which allowed
some optimization for both Intel and AMD
- Fix a long-standing bug where kvm_has_noapic_vcpu could be left
elevated if vCPU creation ultimately failed, causing extra
unnecessary work
- Cleanup the logic for checking if the currently loaded vCPU is
in-kernel
- Harden against underflowing the active mmu_notifier invalidation
count, so that "bad" invalidations (usually due to bugs elsehwere
in the kernel) are detected earlier and are less likely to hang the
kernel
x86 Xen emulation:
- Overlay pages can now be cached based on host virtual address,
instead of guest physical addresses. This removes the need to
reconfigure and invalidate the cache if the guest changes the gpa
but the underlying host virtual address remains the same
- When possible, use a single host TSC value when computing the
deadline for Xen timers in order to improve the accuracy of the
timer emulation
- Inject pending upcall events when the vCPU software-enables its
APIC to fix a bug where an upcall can be lost (and to follow Xen's
behavior)
- Fall back to the slow path instead of warning if "fast" IRQ
delivery of Xen events fails, e.g. if the guest has aliased xAPIC
IDs
RISC-V:
- Support exception and interrupt handling in selftests
- New self test for RISC-V architectural timer (Sstc extension)
- New extension support (Ztso, Zacas)
- Support userspace emulation of random number seed CSRs
ARM:
- Infrastructure for building KVM's trap configuration based on the
architectural features (or lack thereof) advertised in the VM's ID
registers
- Support for mapping vfio-pci BARs as Normal-NC (vaguely similar to
x86's WC) at stage-2, improving the performance of interacting with
assigned devices that can tolerate it
- Conversion of KVM's representation of LPIs to an xarray, utilized
to address serialization some of the serialization on the LPI
injection path
- Support for _architectural_ VHE-only systems, advertised through
the absence of FEAT_E2H0 in the CPU's ID register
- Miscellaneous cleanups, fixes, and spelling corrections to KVM and
selftests
LoongArch:
- Set reserved bits as zero in CPUCFG
- Start SW timer only when vcpu is blocking
- Do not restart SW timer when it is expired
- Remove unnecessary CSR register saving during enter guest
- Misc cleanups and fixes as usual
Generic:
- Clean up Kconfig by removing CONFIG_HAVE_KVM, which was basically
always true on all architectures except MIPS (where Kconfig
determines the available depending on CPU capabilities). It is
replaced either by an architecture-dependent symbol for MIPS, and
IS_ENABLED(CONFIG_KVM) everywhere else
- Factor common "select" statements in common code instead of
requiring each architecture to specify it
- Remove thoroughly obsolete APIs from the uapi headers
- Move architecture-dependent stuff to uapi/asm/kvm.h
- Always flush the async page fault workqueue when a work item is
being removed, especially during vCPU destruction, to ensure that
there are no workers running in KVM code when all references to
KVM-the-module are gone, i.e. to prevent a very unlikely
use-after-free if kvm.ko is unloaded
- Grab a reference to the VM's mm_struct in the async #PF worker
itself instead of gifting the worker a reference, so that there's
no need to remember to *conditionally* clean up after the worker
Selftests:
- Reduce boilerplate especially when utilize selftest TAP
infrastructure
- Add basic smoke tests for SEV and SEV-ES, along with a pile of
library support for handling private/encrypted/protected memory
- Fix benign bugs where tests neglect to close() guest_memfd files"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits)
selftests: kvm: remove meaningless assignments in Makefiles
KVM: riscv: selftests: Add Zacas extension to get-reg-list test
RISC-V: KVM: Allow Zacas extension for Guest/VM
KVM: riscv: selftests: Add Ztso extension to get-reg-list test
RISC-V: KVM: Allow Ztso extension for Guest/VM
RISC-V: KVM: Forward SEED CSR access to user space
KVM: riscv: selftests: Add sstc timer test
KVM: riscv: selftests: Change vcpu_has_ext to a common function
KVM: riscv: selftests: Add guest helper to get vcpu id
KVM: riscv: selftests: Add exception handling support
LoongArch: KVM: Remove unnecessary CSR register saving during enter guest
LoongArch: KVM: Do not restart SW timer when it is expired
LoongArch: KVM: Start SW timer only when vcpu is blocking
LoongArch: KVM: Set reserved bits as zero in CPUCFG
KVM: selftests: Explicitly close guest_memfd files in some gmem tests
KVM: x86/xen: fix recursive deadlock in timer injection
KVM: pfncache: simplify locking and make more self-contained
KVM: x86/xen: remove WARN_ON_ONCE() with false positives in evtchn delivery
KVM: x86/xen: inject vCPU upcall vector when local APIC is enabled
KVM: x86/xen: improve accuracy of Xen timers
...
FEAT_FPMR defines a new EL0 accessible register FPMR use to configure the
FP8 related features added to the architecture at the same time. Detect
support for this register and context switch it for EL0 when present.
Due to the sharing of responsibility for saving floating point state
between the host kernel and KVM FP8 support is not yet implemented in KVM
and a stub similar to that used for SVCR is provided for FPMR in order to
avoid bisection issues. To make it easier to share host state with the
hypervisor we store FPMR as a hardened usercopy field in uw (along with
some padding).
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240306-arm64-2023-dpisa-v5-3-c568edc8ed7f@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Testing KVM with DEBUG_ATOMIC_SLEEP enabled doesn't get far before hitting the
first splat:
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1578
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 13062, name: vgic_lpi_stress
preempt_count: 1, expected: 0
2 locks held by vgic_lpi_stress/13062:
#0: ffff080084553240 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0xc0/0x13f0
#1: ffff800080485f08 (&kvm->arch.config_lock){+.+.}-{3:3}, at: kvm_arch_vcpu_ioctl+0xd60/0x1788
CPU: 19 PID: 13062 Comm: vgic_lpi_stress Tainted: G W O 6.8.0-dbg-DEV #1
Call trace:
dump_backtrace+0xf8/0x148
show_stack+0x20/0x38
dump_stack_lvl+0xb4/0xf8
dump_stack+0x18/0x40
__might_resched+0x248/0x2a0
__might_sleep+0x50/0x88
down_write+0x30/0x150
start_creating+0x90/0x1a0
__debugfs_create_file+0x5c/0x1b0
debugfs_create_file+0x34/0x48
kvm_reset_sys_regs+0x120/0x1e8
kvm_reset_vcpu+0x148/0x270
kvm_arch_vcpu_ioctl+0xddc/0x1788
kvm_vcpu_ioctl+0xb6c/0x13f0
__arm64_sys_ioctl+0x98/0xd8
invoke_syscall+0x48/0x108
el0_svc_common+0xb4/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x54/0x128
el0t_64_sync_handler+0x68/0xc0
el0t_64_sync+0x1a8/0x1b0
kvm_reset_vcpu() disables preemption as it needs to unload vCPU state
from the CPU to twiddle with it, which subsequently explodes when
taking the parent inode's rwsem while creating the idreg debugfs file.
Fix it by moving the initialization to kvm_arch_create_vm_debugfs().
Fixes: 891766581d ("KVM: arm64: Add debugfs file for guest's ID registers")
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240227094115.1723330-3-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Debugging ID register setup can be a complicated affair. Give the
kernel hacker a way to dump that state in an easy to parse way.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-27-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
We unconditionally enable FEAT_MOPS, which is obviously wrong.
So let's only do that when it is advertised to the guest.
Which means we need to rely on a per-vcpu HCRX_EL2 shadow register.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20240214131827.2856277-25-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
We already trap a bunch of existing features for the purpose of
disabling them (MAIR2, POR, ACCDATA, SME...).
Let's move them over to our brand new FGU infrastructure.
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-20-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
In order to efficiently handle system register access being disabled,
and this resulting in an UNDEF exception being injected, we introduce
the (slightly dubious) concept of Fine-Grained UNDEF, modeled after
the architectural Fine-Grained Traps.
For each FGT group, we keep a 64 bit word that has the exact same
bit assignment as the corresponding FGT register, where a 1 indicates
that trapping this register should result in an UNDEF exception being
reinjected.
So far, nothing populates this information, nor sets the corresponding
trap bits.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-18-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
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>
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>
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>
- 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.
* 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>
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>
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>
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>
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>
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
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).
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>
* 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}
...
* 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>
* 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>
* 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>
* 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>
* 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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
* 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>
* 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>
* 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>
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
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
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
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
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
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
* 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>
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>
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
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
* 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
...
- 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.
- 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
...
* 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>
* 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>
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>
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>
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>
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>
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>
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>
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>
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>
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
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>
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>
* 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
...
- 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.
* 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>
* 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>
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>
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
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
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
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
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
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
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
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
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>
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>
* 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>
* 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>
* 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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
* 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
...
* 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>
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>
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
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
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
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
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
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
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
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
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
* 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>
