Commit Graph

678 Commits

Author SHA1 Message Date
Yan Zhao
c9c1e20b4c KVM: x86: Introduce Intel specific quirk KVM_X86_QUIRK_IGNORE_GUEST_PAT
Introduce an Intel specific quirk KVM_X86_QUIRK_IGNORE_GUEST_PAT to have
KVM ignore guest PAT when this quirk is enabled.

On AMD platforms, KVM always honors guest PAT.  On Intel however there are
two issues.  First, KVM *cannot* honor guest PAT if CPU feature self-snoop
is not supported. Second, UC access on certain Intel platforms can be very
slow[1] and honoring guest PAT on those platforms may break some old
guests that accidentally specify video RAM as UC. Those old guests may
never expect the slowness since KVM always forces WB previously. See [2].

So, introduce a quirk that KVM can enable by default on all Intel platforms
to avoid breaking old unmodifiable guests. Newer userspace can disable this
quirk if it wishes KVM to honor guest PAT; disabling the quirk will fail
if self-snoop is not supported, i.e. if KVM cannot obey the wish.

The quirk is a no-op on AMD and also if any assigned devices have
non-coherent DMA.  This is not an issue, as KVM_X86_QUIRK_CD_NW_CLEARED is
another example of a quirk that is sometimes automatically disabled.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Link: https://lore.kernel.org/all/Ztl9NWCOupNfVaCA@yzhao56-desk.sh.intel.com # [1]
Link: https://lore.kernel.org/all/87jzfutmfc.fsf@redhat.com # [2]
Message-ID: <20250224070946.31482-1-yan.y.zhao@intel.com>
[Use supported_quirks/inapplicable_quirks to support both AMD and
 no-self-snoop cases, as well as to remove the shadow_memtype_mask check
 from kvm_mmu_may_ignore_guest_pat(). - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-14 14:20:58 -04:00
Binbin Wu
79462faa2b KVM: TDX: Handle TDG.VP.VMCALL<ReportFatalError>
Convert TDG.VP.VMCALL<ReportFatalError> to KVM_EXIT_SYSTEM_EVENT with
a new type KVM_SYSTEM_EVENT_TDX_FATAL and forward it to userspace for
handling.

TD guest can use TDG.VP.VMCALL<ReportFatalError> to report the fatal
error it has experienced.  This hypercall is special because TD guest
is requesting a termination with the error information, KVM needs to
forward the hypercall to userspace anyway, KVM doesn't do parsing or
conversion, it just dumps the 16 general-purpose registers to userspace
and let userspace decide what to do.

Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com>
Message-ID: <20250222014225.897298-8-binbin.wu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-14 14:20:55 -04:00
Oliver Upton
5980a69370 KVM: arm64: Fix documentation for KVM_CAP_ARM_WRITABLE_IMP_ID_REGS
The capability actually fails with EINVAL if vCPUs have already been
created.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250305230825.484091-4-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-05 16:56:58 -08:00
Andre Przywara
faf7714a47 KVM: arm64: nv: Allow userland to set VGIC maintenance IRQ
The VGIC maintenance IRQ signals various conditions about the LRs, when
the GIC's virtualization extension is used.
So far we didn't need it, but nested virtualization needs to know about
this interrupt, so add a userland interface to setup the IRQ number.
The architecture mandates that it must be a PPI, on top of that this code
only exports a per-device option, so the PPI is the same on all VCPUs.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
[added some bits of documentation]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250225172930.1850838-16-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-03-03 14:57:10 -08:00
Shameer Kolothum
c0000e58c7 KVM: arm64: Introduce KVM_REG_ARM_VENDOR_HYP_BMAP_2
The vendor_hyp_bmap bitmap holds the information about the Vendor Hyp
services available to the user space and can be get/set using
{G, S}ET_ONE_REG interfaces. This is done using the pseudo-firmware
bitmap register KVM_REG_ARM_VENDOR_HYP_BMAP.

At present, this bitmap is a 64 bit one and since the function numbers
for newly added DISCOVER_IPML_* hypercalls are 64-65, introduce
another pseudo-firmware bitmap register KVM_REG_ARM_VENDOR_HYP_BMAP_2.

Reviewed-by: Sebastian Ott <sebott@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20250221140229.12588-4-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-26 13:30:36 -08:00
Shameer Kolothum
57e5cc9b8a KVM: arm64: Specify hypercall ABI for retrieving target implementations
If the Guest requires migration to multiple targets, these hypercalls
will provide a way to retrieve the target CPU implementations from
the user space VMM.

Subsequent patch will use this to enable the associated errata.

Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Suggested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20250221140229.12588-3-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-26 13:30:18 -08:00
Oliver Upton
d766d87cf4 KVM: arm64: Document ordering requirements for irqbypass
One of the not-so-obvious requirements for restoring a VM is ensuring
that the vITS has been restored _before_ creating any irqbypass mappings.
This is because KVM needs to get the guest translation for MSIs to
correctly assemble the vLPI mapping getting installed in the physical
ITS.

Document the restore ordering requirements necessary for GICv4 vLPI
injection to work.

Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250226183124.82094-5-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-26 13:22:49 -08:00
Sebastian Ott
3adaee7830 KVM: arm64: Allow userspace to change the implementation ID registers
KVM's treatment of the ID registers that describe the implementation
(MIDR, REVIDR, and AIDR) is interesting, to say the least. On the
userspace-facing end of it, KVM presents the values of the boot CPU on
all vCPUs and treats them as invariant. On the guest side of things KVM
presents the hardware values of the local CPU, which can change during
CPU migration in a big-little system.

While one may call this fragile, there is at least some degree of
predictability around it. For example, if a VMM wanted to present
big-little to a guest, it could affine vCPUs accordingly to the correct
clusters.

All of this makes a giant mess out of adding support for making these
implementation ID registers writable. Avoid breaking the rather subtle
ABI around the old way of doing things by requiring opt-in from
userspace to make the registers writable.

When the cap is enabled, allow userspace to set MIDR, REVIDR, and AIDR
to any non-reserved value and present those values consistently across
all vCPUs.

Signed-off-by: Sebastian Ott <sebott@redhat.com>
[oliver: changelog, capability]
Link: https://lore.kernel.org/r/20250225005401.679536-5-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-02-26 01:32:16 -08:00
Sean Christopherson
5c17848134 KVM: x86/xen: Restrict hypercall MSR to unofficial synthetic range
Reject userspace attempts to set the Xen hypercall page MSR to an index
outside of the "standard" virtualization range [0x40000000, 0x4fffffff],
as KVM is not equipped to handle collisions with real MSRs, e.g. KVM
doesn't update MSR interception, conflicts with VMCS/VMCB fields, special
case writes in KVM, etc.

While the MSR index isn't strictly ABI, i.e. can theoretically float to
any value, in practice no known VMM sets the MSR index to anything other
than 0x40000000 or 0x40000200.

Cc: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
Link: https://lore.kernel.org/r/20250215011437.1203084-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-02-24 08:59:55 -08:00
James Houghton
61d65f2dc7 KVM: x86/mmu: Don't force atomic update if only the Accessed bit is volatile
Don't force SPTE modifications to be done atomically if the only volatile
bit in the SPTE is the Accessed bit.  KVM and the primary MMU tolerate
stale aging state, and the probability of an Accessed bit A/D assist being
clobbered *and* affecting again is likely far lower than the probability
of consuming stale information due to not flushing TLBs when aging.

Rename spte_has_volatile_bits() to spte_needs_atomic_update() to better
capture the nature of the helper.

Opportunstically do s/write/update on the TDP MMU wrapper, as it's not
simply the "write" that needs to be done atomically, it's the entire
update, i.e. the entire read-modify-write operation needs to be done
atomically so that KVM has an accurate view of the old SPTE.

Leave kvm_tdp_mmu_write_spte_atomic() as is.  While the name is imperfect,
it pairs with kvm_tdp_mmu_write_spte(), which in turn pairs with
kvm_tdp_mmu_read_spte().  And renaming all of those isn't obviously a net
positive, and would require significant churn.

Signed-off-by: James Houghton <jthoughton@google.com>
Link: https://lore.kernel.org/r/20250204004038.1680123-6-jthoughton@google.com
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-02-14 07:16:45 -08:00
Claudio Imbrenda
413c98f24c KVM: s390: fake memslot for ucontrol VMs
Create a fake memslot for ucontrol VMs. The fake memslot identity-maps
userspace.

Now memslots will always be present, and ucontrol is not a special case
anymore.

Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/r/20250123144627.312456-4-imbrenda@linux.ibm.com
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20250123144627.312456-4-imbrenda@linux.ibm.com>
2025-01-31 12:03:52 +01:00
Linus Torvalds
e2ee2e9b15 KVM/arm64 updates for 6.14
* New features:
 
   - Support for non-protected guest in protected mode, achieving near
     feature parity with the non-protected mode
 
   - Support for the EL2 timers as part of the ongoing NV support
 
   - Allow control of hardware tracing for nVHE/hVHE
 
 * Improvements, fixes and cleanups:
 
   - Massive cleanup of the debug infrastructure, making it a bit less
     awkward and definitely easier to maintain. This should pave the
     way for further optimisations
 
   - Complete rewrite of pKVM's fixed-feature infrastructure, aligning
     it with the rest of KVM and making the code easier to follow
 
   - Large simplification of pKVM's memory protection infrastructure
 
   - Better handling of RES0/RES1 fields for memory-backed system
     registers
 
   - Add a workaround for Qualcomm's Snapdragon X CPUs, which suffer
     from a pretty nasty timer bug
 
   - Small collection of cleanups and low-impact fixes
 -----BEGIN PGP SIGNATURE-----
 
 iQFEBAABCgAuFiEEPxTL6PPUbjXGY88ct6xw3ITBYzQFAmeYqJcQHHdpbGxAa2Vy
 bmVsLm9yZwAKCRC3rHDchMFjNLUhCACxUTMVQXhfW3qbh0UQxPd7XXvjI+Hm7SPS
 wDuVTle4jrFVGHxuZqtgWLmx8hD7bqO965qmFgbevKlwsRY33onH2nbH4i4AcwbA
 jcdM4yMHZI4+Qmnb4G5ZJ89IwjAhHPZTBOV5KRhyHQ/qtRciHHtOgJde7II9fd68
 uIESg4SSSyUzI47YSEHmGVmiBIhdQhq2qust0m6NPFalEGYstPbpluPQ6R1CsDqK
 v14TIAW7t0vSPucBeODxhA5gEa2JsvNi+sqA+DF/ELH2ZqpkuR7rofgMGblaXCSD
 JXa5xamRB9dI5zi8vatwfOzYlog+/gzmPqMh/9JXpiDGHxJe0vlz
 =tQ8F
 -----END PGP SIGNATURE-----

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull KVM/arm64 updates from Will Deacon:
 "New features:

   - Support for non-protected guest in protected mode, achieving near
     feature parity with the non-protected mode

   - Support for the EL2 timers as part of the ongoing NV support

   - Allow control of hardware tracing for nVHE/hVHE

  Improvements, fixes and cleanups:

   - Massive cleanup of the debug infrastructure, making it a bit less
     awkward and definitely easier to maintain. This should pave the way
     for further optimisations

   - Complete rewrite of pKVM's fixed-feature infrastructure, aligning
     it with the rest of KVM and making the code easier to follow

   - Large simplification of pKVM's memory protection infrastructure

   - Better handling of RES0/RES1 fields for memory-backed system
     registers

   - Add a workaround for Qualcomm's Snapdragon X CPUs, which suffer
     from a pretty nasty timer bug

   - Small collection of cleanups and low-impact fixes"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (87 commits)
  arm64/sysreg: Get rid of TRFCR_ELx SysregFields
  KVM: arm64: nv: Fix doc header layout for timers
  KVM: arm64: nv: Apply RESx settings to sysreg reset values
  KVM: arm64: nv: Always evaluate HCR_EL2 using sanitising accessors
  KVM: arm64: Fix selftests after sysreg field name update
  coresight: Pass guest TRFCR value to KVM
  KVM: arm64: Support trace filtering for guests
  KVM: arm64: coresight: Give TRBE enabled state to KVM
  coresight: trbe: Remove redundant disable call
  arm64/sysreg/tools: Move TRFCR definitions to sysreg
  tools: arm64: Update sysreg.h header files
  KVM: arm64: Drop pkvm_mem_transition for host/hyp donations
  KVM: arm64: Drop pkvm_mem_transition for host/hyp sharing
  KVM: arm64: Drop pkvm_mem_transition for FF-A
  KVM: arm64: Explicitly handle BRBE traps as UNDEFINED
  KVM: arm64: vgic: Use str_enabled_disabled() in vgic_v3_probe()
  arm64: kvm: Introduce nvhe stack size constants
  KVM: arm64: Fix nVHE stacktrace VA bits mask
  KVM: arm64: Fix FEAT_MTE in pKVM
  Documentation: Update the behaviour of "kvm-arm.mode"
  ...
2025-01-28 09:01:36 -08:00
Linus Torvalds
0f8e26b38d Loongarch:
* Clear LLBCTL if secondary mmu mapping changes.
 
 * Add hypercall service support for usermode VMM.
 
 x86:
 
 * Add a comment to kvm_mmu_do_page_fault() to explain why KVM performs a
   direct call to kvm_tdp_page_fault() when RETPOLINE is enabled.
 
 * Ensure that all SEV code is compiled out when disabled in Kconfig, even
   if building with less brilliant compilers.
 
 * Remove a redundant TLB flush on AMD processors when guest CR4.PGE changes.
 
 * Use str_enabled_disabled() to replace open coded strings.
 
 * Drop kvm_x86_ops.hwapic_irr_update() as KVM updates hardware's APICv cache
   prior to every VM-Enter.
 
 * Overhaul KVM's CPUID feature infrastructure to track all vCPU capabilities
   instead of just those where KVM needs to manage state and/or explicitly
   enable the feature in hardware.  Along the way, refactor the code to make
   it easier to add features, and to make it more self-documenting how KVM
   is handling each feature.
 
 * Rework KVM's handling of VM-Exits during event vectoring; this plugs holes
   where KVM unintentionally puts the vCPU into infinite loops in some scenarios
   (e.g. if emulation is triggered by the exit), and brings parity between VMX
   and SVM.
 
 * Add pending request and interrupt injection information to the kvm_exit and
   kvm_entry tracepoints respectively.
 
 * Fix a relatively benign flaw where KVM would end up redoing RDPKRU when
   loading guest/host PKRU, due to a refactoring of the kernel helpers that
   didn't account for KVM's pre-checking of the need to do WRPKRU.
 
 * Make the completion of hypercalls go through the complete_hypercall
   function pointer argument, no matter if the hypercall exits to
   userspace or not.  Previously, the code assumed that KVM_HC_MAP_GPA_RANGE
   specifically went to userspace, and all the others did not; the new code
   need not special case KVM_HC_MAP_GPA_RANGE and in fact does not care at
   all whether there was an exit to userspace or not.
 
 * As part of enabling TDX virtual machines, support support separation of
   private/shared EPT into separate roots.  When TDX will be enabled, operations
   on private pages will need to go through the privileged TDX Module via SEAMCALLs;
   as a result, they are limited and relatively slow compared to reading a PTE.
   The patches included in 6.14 allow KVM to keep a mirror of the private EPT in
   host memory, and define entries in kvm_x86_ops to operate on external page
   tables such as the TDX private EPT.
 
 * The recently introduced conversion of the NX-page reclamation kthread to
   vhost_task moved the task under the main process.  The task is created as
   soon as KVM_CREATE_VM was invoked and this, of course, broke userspace that
   didn't expect to see any child task of the VM process until it started
   creating its own userspace threads.  In particular crosvm refuses to fork()
   if procfs shows any child task, so unbreak it by creating the task lazily.
   This is arguably a userspace bug, as there can be other kinds of legitimate
   worker tasks and they wouldn't impede fork(); but it's not like userspace
   has a way to distinguish kernel worker tasks right now.  Should they show
   as "Kthread: 1" in proc/.../status?
 
 x86 - Intel:
 
 * Fix a bug where KVM updates hardware's APICv cache of the highest ISR bit
   while L2 is active, while ultimately results in a hardware-accelerated L1
   EOI effectively being lost.
 
 * Honor event priority when emulating Posted Interrupt delivery during nested
   VM-Enter by queueing KVM_REQ_EVENT instead of immediately handling the
   interrupt.
 
 * Rework KVM's processing of the Page-Modification Logging buffer to reap
   entries in the same order they were created, i.e. to mark gfns dirty in the
   same order that hardware marked the page/PTE dirty.
 
 * Misc cleanups.
 
 Generic:
 
 * Cleanup and harden kvm_set_memory_region(); add proper lockdep assertions when
   setting memory regions and add a dedicated API for setting KVM-internal
   memory regions.  The API can then explicitly disallow all flags for
   KVM-internal memory regions.
 
 * Explicitly verify the target vCPU is online in kvm_get_vcpu() to fix a bug
   where KVM would return a pointer to a vCPU prior to it being fully online,
   and give kvm_for_each_vcpu() similar treatment to fix a similar flaw.
 
 * Wait for a vCPU to come online prior to executing a vCPU ioctl, to fix a
   bug where userspace could coerce KVM into handling the ioctl on a vCPU that
   isn't yet onlined.
 
 * Gracefully handle xarray insertion failures; even though such failures are
   impossible in practice after xa_reserve(), reserving an entry is always followed
   by xa_store() which does not know (or differentiate) whether there was an
   xa_reserve() before or not.
 
 RISC-V:
 
 * Zabha, Svvptc, and Ziccrse extension support for guests.  None of them
   require anything in KVM except for detecting them and marking them
   as supported; Zabha adds byte and halfword atomic operations, while the
   others are markers for specific operation of the TLB and of LL/SC
   instructions respectively.
 
 * Virtualize SBI system suspend extension for Guest/VM
 
 * Support firmware counters which can be used by the guests to collect
   statistics about traps that occur in the host.
 
 Selftests:
 
 * Rework vcpu_get_reg() to return a value instead of using an out-param, and
   update all affected arch code accordingly.
 
 * Convert the max_guest_memory_test into a more generic mmu_stress_test.
   The basic gist of the "conversion" is to have the test do mprotect() on
   guest memory while vCPUs are accessing said memory, e.g. to verify KVM
   and mmu_notifiers are working as intended.
 
 * Play nice with treewrite builds of unsupported architectures, e.g. arm
   (32-bit), as KVM selftests' Makefile doesn't do anything to ensure the
   target architecture is actually one KVM selftests supports.
 
 * Use the kernel's $(ARCH) definition instead of the target triple for arch
   specific directories, e.g. arm64 instead of aarch64, mainly so as not to
   be different from the rest of the kernel.
 
 * Ensure that format strings for logging statements are checked by the
   compiler even when the logging statement itself is disabled.
 
 * Attempt to whack the last LLC references/misses mole in the Intel PMU
   counters test by adding a data load and doing CLFLUSH{OPT} on the data
   instead of the code being executed.  It seems that modern Intel CPUs
   have learned new code prefetching tricks that bypass the PMU counters.
 
 * Fix a flaw in the Intel PMU counters test where it asserts that events
   are counting correctly without actually knowing what the events count
   given the underlying hardware; this can happen if Intel reuses a
   formerly microarchitecture-specific event encoding as an architectural
   event, as was the case for Top-Down Slots.
 -----BEGIN PGP SIGNATURE-----
 
 iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmeTuzoUHHBib256aW5p
 QHJlZGhhdC5jb20ACgkQv/vSX3jHroOkBwf8CRNExYaM3j9y2E7mmo6AiL2ug6+J
 Uy5Hai1poY48pPwKC6ke3EWT8WVsgj/Py5pCeHvLojQchWNjCCYNfSQluJdkRxwG
 DgP3QUljSxEJWBeSwyTRcKM+IySi5hZd1IFo3gePFRB829Jpnj05vjbvCyv8gIwU
 y3HXxSYDsViaaFoNg4OlZFsIGis7mtknsZzk++QjuCXmxNa6UCbv3qvE/UkVLhVg
 WH65RTRdjk+EsdwaOMHKuUvQoGa+iM4o39b6bqmw8+ZMK39+y33WeTX/y5RXsp1N
 tUUBRfS+MuuYgC/6LmTr66EkMzoChxk3Dp3kKUaCBcfqRC8PxQag5reZhw==
 =NEaO
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "Loongarch:

   - Clear LLBCTL if secondary mmu mapping changes

   - Add hypercall service support for usermode VMM

  x86:

   - Add a comment to kvm_mmu_do_page_fault() to explain why KVM
     performs a direct call to kvm_tdp_page_fault() when RETPOLINE is
     enabled

   - Ensure that all SEV code is compiled out when disabled in Kconfig,
     even if building with less brilliant compilers

   - Remove a redundant TLB flush on AMD processors when guest CR4.PGE
     changes

   - Use str_enabled_disabled() to replace open coded strings

   - Drop kvm_x86_ops.hwapic_irr_update() as KVM updates hardware's
     APICv cache prior to every VM-Enter

   - Overhaul KVM's CPUID feature infrastructure to track all vCPU
     capabilities instead of just those where KVM needs to manage state
     and/or explicitly enable the feature in hardware. Along the way,
     refactor the code to make it easier to add features, and to make it
     more self-documenting how KVM is handling each feature

   - Rework KVM's handling of VM-Exits during event vectoring; this
     plugs holes where KVM unintentionally puts the vCPU into infinite
     loops in some scenarios (e.g. if emulation is triggered by the
     exit), and brings parity between VMX and SVM

   - Add pending request and interrupt injection information to the
     kvm_exit and kvm_entry tracepoints respectively

   - Fix a relatively benign flaw where KVM would end up redoing RDPKRU
     when loading guest/host PKRU, due to a refactoring of the kernel
     helpers that didn't account for KVM's pre-checking of the need to
     do WRPKRU

   - Make the completion of hypercalls go through the complete_hypercall
     function pointer argument, no matter if the hypercall exits to
     userspace or not.

     Previously, the code assumed that KVM_HC_MAP_GPA_RANGE specifically
     went to userspace, and all the others did not; the new code need
     not special case KVM_HC_MAP_GPA_RANGE and in fact does not care at
     all whether there was an exit to userspace or not

   - As part of enabling TDX virtual machines, support support
     separation of private/shared EPT into separate roots.

     When TDX will be enabled, operations on private pages will need to
     go through the privileged TDX Module via SEAMCALLs; as a result,
     they are limited and relatively slow compared to reading a PTE.

     The patches included in 6.14 allow KVM to keep a mirror of the
     private EPT in host memory, and define entries in kvm_x86_ops to
     operate on external page tables such as the TDX private EPT

   - The recently introduced conversion of the NX-page reclamation
     kthread to vhost_task moved the task under the main process. The
     task is created as soon as KVM_CREATE_VM was invoked and this, of
     course, broke userspace that didn't expect to see any child task of
     the VM process until it started creating its own userspace threads.

     In particular crosvm refuses to fork() if procfs shows any child
     task, so unbreak it by creating the task lazily. This is arguably a
     userspace bug, as there can be other kinds of legitimate worker
     tasks and they wouldn't impede fork(); but it's not like userspace
     has a way to distinguish kernel worker tasks right now. Should they
     show as "Kthread: 1" in proc/.../status?

  x86 - Intel:

   - Fix a bug where KVM updates hardware's APICv cache of the highest
     ISR bit while L2 is active, while ultimately results in a
     hardware-accelerated L1 EOI effectively being lost

   - Honor event priority when emulating Posted Interrupt delivery
     during nested VM-Enter by queueing KVM_REQ_EVENT instead of
     immediately handling the interrupt

   - Rework KVM's processing of the Page-Modification Logging buffer to
     reap entries in the same order they were created, i.e. to mark gfns
     dirty in the same order that hardware marked the page/PTE dirty

   - Misc cleanups

  Generic:

   - Cleanup and harden kvm_set_memory_region(); add proper lockdep
     assertions when setting memory regions and add a dedicated API for
     setting KVM-internal memory regions. The API can then explicitly
     disallow all flags for KVM-internal memory regions

   - Explicitly verify the target vCPU is online in kvm_get_vcpu() to
     fix a bug where KVM would return a pointer to a vCPU prior to it
     being fully online, and give kvm_for_each_vcpu() similar treatment
     to fix a similar flaw

   - Wait for a vCPU to come online prior to executing a vCPU ioctl, to
     fix a bug where userspace could coerce KVM into handling the ioctl
     on a vCPU that isn't yet onlined

   - Gracefully handle xarray insertion failures; even though such
     failures are impossible in practice after xa_reserve(), reserving
     an entry is always followed by xa_store() which does not know (or
     differentiate) whether there was an xa_reserve() before or not

  RISC-V:

   - Zabha, Svvptc, and Ziccrse extension support for guests. None of
     them require anything in KVM except for detecting them and marking
     them as supported; Zabha adds byte and halfword atomic operations,
     while the others are markers for specific operation of the TLB and
     of LL/SC instructions respectively

   - Virtualize SBI system suspend extension for Guest/VM

   - Support firmware counters which can be used by the guests to
     collect statistics about traps that occur in the host

  Selftests:

   - Rework vcpu_get_reg() to return a value instead of using an
     out-param, and update all affected arch code accordingly

   - Convert the max_guest_memory_test into a more generic
     mmu_stress_test. The basic gist of the "conversion" is to have the
     test do mprotect() on guest memory while vCPUs are accessing said
     memory, e.g. to verify KVM and mmu_notifiers are working as
     intended

   - Play nice with treewrite builds of unsupported architectures, e.g.
     arm (32-bit), as KVM selftests' Makefile doesn't do anything to
     ensure the target architecture is actually one KVM selftests
     supports

   - Use the kernel's $(ARCH) definition instead of the target triple
     for arch specific directories, e.g. arm64 instead of aarch64,
     mainly so as not to be different from the rest of the kernel

   - Ensure that format strings for logging statements are checked by
     the compiler even when the logging statement itself is disabled

   - Attempt to whack the last LLC references/misses mole in the Intel
     PMU counters test by adding a data load and doing CLFLUSH{OPT} on
     the data instead of the code being executed. It seems that modern
     Intel CPUs have learned new code prefetching tricks that bypass the
     PMU counters

   - Fix a flaw in the Intel PMU counters test where it asserts that
     events are counting correctly without actually knowing what the
     events count given the underlying hardware; this can happen if
     Intel reuses a formerly microarchitecture-specific event encoding
     as an architectural event, as was the case for Top-Down Slots"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (151 commits)
  kvm: defer huge page recovery vhost task to later
  KVM: x86/mmu: Return RET_PF* instead of 1 in kvm_mmu_page_fault()
  KVM: Disallow all flags for KVM-internal memslots
  KVM: x86: Drop double-underscores from __kvm_set_memory_region()
  KVM: Add a dedicated API for setting KVM-internal memslots
  KVM: Assert slots_lock is held when setting memory regions
  KVM: Open code kvm_set_memory_region() into its sole caller (ioctl() API)
  LoongArch: KVM: Add hypercall service support for usermode VMM
  LoongArch: KVM: Clear LLBCTL if secondary mmu mapping is changed
  KVM: SVM: Use str_enabled_disabled() helper in svm_hardware_setup()
  KVM: VMX: read the PML log in the same order as it was written
  KVM: VMX: refactor PML terminology
  KVM: VMX: Fix comment of handle_vmx_instruction()
  KVM: VMX: Reinstate __exit attribute for vmx_exit()
  KVM: SVM: Use str_enabled_disabled() helper in sev_hardware_setup()
  KVM: x86: Avoid double RDPKRU when loading host/guest PKRU
  KVM: x86: Use LVT_TIMER instead of an open coded literal
  RISC-V: KVM: Add new exit statstics for redirected traps
  RISC-V: KVM: Update firmware counters for various events
  RISC-V: KVM: Redirect instruction access fault trap to guest
  ...
2025-01-25 09:55:09 -08:00
Linus Torvalds
382e391365 hyperv-next for v6.14
-----BEGIN PGP SIGNATURE-----
 
 iQFHBAABCgAxFiEEIbPD0id6easf0xsudhRwX5BBoF4FAmeTFQ4THHdlaS5saXVA
 a2VybmVsLm9yZwAKCRB2FHBfkEGgXqMWB/4uHjnu50u+m00OwXAKQr6i92zh50BZ
 RQragd9s9C8tuUNwPDmS/ct2BNAhoy43KJ0ClegdZjKxT1Ys8cLv4Wr5CaGckqWq
 +WCHqTgt+cPe0vUofqahB5wiAZMsnBgzFkV/OfFwBx0wkub9y5T3qVq5KapYlaDI
 7Gftb+wg1AAsrdZ/HuLRy5ZVvkM/73rU2uoi8WXjr/T14E1krCFR/qirLd1OXo6Q
 Jb97qhnCt/N9JPwIq5/VnYWde5Mpqz6UgtA2rFLDXgNGz+h9/ND6ecWFHjZWNVdc
 AKWZTO5t+fRVBOSyahoyRoYSntPw3wlxyL7A2/54h6j4Dex7wLt6NQBj
 =empO
 -----END PGP SIGNATURE-----

Merge tag 'hyperv-next-signed-20250123' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

 - Introduce a new set of Hyper-V headers in include/hyperv and replace
   the old hyperv-tlfs.h with the new headers (Nuno Das Neves)

 - Fixes for the Hyper-V VTL mode (Roman Kisel)

 - Fixes for cpu mask usage in Hyper-V code (Michael Kelley)

 - Document the guest VM hibernation behaviour (Michael Kelley)

 - Miscellaneous fixes and cleanups (Jacob Pan, John Starks, Naman Jain)

* tag 'hyperv-next-signed-20250123' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Documentation: hyperv: Add overview of guest VM hibernation
  hyperv: Do not overlap the hvcall IO areas in hv_vtl_apicid_to_vp_id()
  hyperv: Do not overlap the hvcall IO areas in get_vtl()
  hyperv: Enable the hypercall output page for the VTL mode
  hv_balloon: Fallback to generic_online_page() for non-HV hot added mem
  Drivers: hv: vmbus: Log on missing offers if any
  Drivers: hv: vmbus: Wait for boot-time offers during boot and resume
  uio_hv_generic: Add a check for HV_NIC for send, receive buffers setup
  iommu/hyper-v: Don't assume cpu_possible_mask is dense
  Drivers: hv: Don't assume cpu_possible_mask is dense
  x86/hyperv: Don't assume cpu_possible_mask is dense
  hyperv: Remove the now unused hyperv-tlfs.h files
  hyperv: Switch from hyperv-tlfs.h to hyperv/hvhdk.h
  hyperv: Add new Hyper-V headers in include/hyperv
  hyperv: Clean up unnecessary #includes
  hyperv: Move hv_connection_id to hyperv-tlfs.h
2025-01-25 09:22:55 -08:00
Linus Torvalds
d0f93ac2c3 Documentation changes this time around include:
- Quite a bit of Chinese and Spanish translation work.
 
 - Clarifying that Git commit IDs >12chars are OK
 
 - A new nvme-multipath document
 
 - A reorganization of the admin-guide top-level page to make it readable
 
 - Clarification of the role of Acked-by and maintainer discretion on their
   acceptance.
 
 - Some reorganization of debugging-oriented docs.
 
 ...and typo fixes, documentation updates, etc. as usual.
 -----BEGIN PGP SIGNATURE-----
 
 iQFDBAABCAAtFiEEIw+MvkEiF49krdp9F0NaE2wMflgFAmeOp8EPHGNvcmJldEBs
 d24ubmV0AAoJEBdDWhNsDH5YipUH/iffvlVYuqoVdPUFWdmsiNjwOCRE2MIfp8qO
 tPTRRHJAny+NlFT0IWlGUbLNoNXtvpN47YlkaeAjdrsjASerfpwzje7t4Z1B+jWT
 0YwGBCvDIGasfRCx7D14+w5aqkEEynfsy+QurwcuDxcHMQGwt7ZCuTNOVO6BULEr
 L++BMwqapUr5IemP4ItQqDVVF9sp6bWEhaOnTTJCLU6oG23uUSSA/59sJmwDJUk7
 6J3VGO1An4Jte9WX7qkVrSBNO5cOOhaFiFXIeNxfOioOPctBwxKiHDJnzVud8ipz
 R+tnUI/8hEvyJ7GZFezyZxmMnFs0P2DEYAkaN+hBs/nUjx0dKUg=
 =YxaS
 -----END PGP SIGNATURE-----

Merge tag 'docs-6.14' of git://git.lwn.net/linux

Pull Documentation updates from Jonathan Corbet:

 - Quite a bit of Chinese and Spanish translation work

 - Clarifying that Git commit IDs >12chars are OK

 - A new nvme-multipath document

 - A reorganization of the admin-guide top-level page to make it
   readable

 - Clarification of the role of Acked-by and maintainer discretion on
   their acceptance

 - Some reorganization of debugging-oriented docs

... and typo fixes, documentation updates, etc as usual

* tag 'docs-6.14' of git://git.lwn.net/linux: (50 commits)
  Documentation: Fix x86_64 UEFI outdated references to elilo
  Documentation/sysctl: Add timer_migration to kernel.rst
  docs/mm: Physical memory: Remove zone_t
  docs: submitting-patches: clarify that signers may use their discretion on tags
  docs: submitting-patches: clarify difference between Acked-by and Reviewed-by
  docs: submitting-patches: clarify Acked-by and introduce "# Suffix"
  Documentation: bug-hunting.rst: remove odd contact information
  docs/zh_CN: Add sak index Chinese translation
  doc: module: DEFAULT_SYMBOL_NAMESPACE must be defined before #includes
  doc: module: Fix documented type of namespace
  Documentation/kernel-parameters: Fix a reference to vga-softcursor.rst
  docs/zh_CN: Add landlock index Chinese translation
  Documentation: Fix typo localmodonfig -> localmodconfig
  overlayfs.rst: Fix and improve grammar
  docs/zh_CN: Add siphash index Chinese translation
  docs/zh_CN: Add security IMA-templates Chinese translation
  docs/zh_CN: Add security digsig Chinese translation
  Align git commit ID abbreviation guidelines and checks
  docs: process: submitting-patches: split canonical patch format section
  docs/zh_CN: Add security lsm Chinese translation
  ...
2025-01-21 18:00:00 -08:00
Paolo Bonzini
4f7ff70c05 KVM x86 misc changes for 6.14:
- Overhaul KVM's CPUID feature infrastructure to replace "governed" features
    with per-vCPU tracking of the vCPU's capabailities for all features.  Along
    the way, refactor the code to make it easier to add/modify features, and
    add a variety of self-documenting macro types to again simplify adding new
    features and to help readers understand KVM's handling of existing features.
 
  - Rework KVM's handling of VM-Exits during event vectoring to plug holes where
    KVM unintentionally puts the vCPU into infinite loops in some scenarios,
    e.g. if emulation is triggered by the exit, and to bring parity between VMX
    and SVM.
 
  - Add pending request and interrupt injection information to the kvm_exit and
    kvm_entry tracepoints respectively.
 
  - Fix a relatively benign flaw where KVM would end up redoing RDPKRU when
    loading guest/host PKRU due to a refactoring of the kernel helpers that
    didn't account for KVM's pre-checking of the need to do WRPKRU.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEKTobbabEP7vbhhN9OlYIJqCjN/0FAmeJngsACgkQOlYIJqCj
 N/1dfA/+NIZmnd8OV9Zvc6HGxrzgt4QsM9pmsUmrfkDWefxMYIAMeaW8Vn4CJfRf
 zY/UcqyNI7JYxSiuVTckz+Tf54HhqYaLrUwILGCQ49koirZx+aQT1OUfjLroVMlh
 ffX1i6GOoLNtxjb9MXM/heLVdUbvmzQMSFkd/AkOH+nrOtDNOiPlZfjHsewj9zrf
 BNJGhzvT4M6vc/AsScC7tc0yFD5KKFRv8tVwJ6Zf1nWKyUDOSpMTWkVnq6geKJPZ
 iGBZPPNg55Oy1g6uj6VYWmqYTD8Qioz5jtEJ/8pPHdAyIFo21s81bfJc548d+QLh
 KfrL1K7TrCOhSAGC3Cb3lTLeq2immmGHaiTBLwGABG4MhpiX4NVpMMdOyFbVLMOS
 HIYuwXwDckm1pfU7/w+PgPaakCyPrXQntm+3Y2pvDOoY6e2JbwodK4j8BvvQda35
 8TrYKEGFvq5aij7Iw1O9TUoLAocDM/sHIHE6BCazHyzKBIv9xLRFeabiCQ+A1pwv
 gZk5u0+j+DPpLdeLhbMYhIXUtr3bvyMYvc+tRkG716f8ubAE3+Kn5BEDo4Ot2DcT
 vc+NTRYYWN6zavHiJH3Ddt153yj256JCZhLwCdfbryCQdz3Mpy16m36tgkDRd3lR
 QT4IkPQo1Vl/aU0yiE/dhnJgh1rTO26YQjZoHs5Oj16d0HRrKyc=
 =32mM
 -----END PGP SIGNATURE-----

Merge tag 'kvm-x86-misc-6.14' of https://github.com/kvm-x86/linux into HEAD

KVM x86 misc changes for 6.14:

 - Overhaul KVM's CPUID feature infrastructure to track all vCPU capabilities
   instead of just those where KVM needs to manage state and/or explicitly
   enable the feature in hardware.  Along the way, refactor the code to make
   it easier to add features, and to make it more self-documenting how KVM
   is handling each feature.

 - Rework KVM's handling of VM-Exits during event vectoring; this plugs holes
   where KVM unintentionally puts the vCPU into infinite loops in some scenarios
   (e.g. if emulation is triggered by the exit), and brings parity between VMX
   and SVM.

 - Add pending request and interrupt injection information to the kvm_exit and
   kvm_entry tracepoints respectively.

 - Fix a relatively benign flaw where KVM would end up redoing RDPKRU when
   loading guest/host PKRU, due to a refactoring of the kernel helpers that
   didn't account for KVM's pre-checking of the need to do WRPKRU.
2025-01-20 06:49:39 -05:00
Marc Zyngier
544786361d KVM: arm64: nv: Fix doc header layout for timers
Stephen reports that 'make htmldocs' spits out a warning
("Documentation/virt/kvm/devices/vcpu.rst:147: WARNING: Definition
list ends without a blank line; unexpected unindent.").

Fix it by keeping all the timer attributes on a single line.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-16 10:27:10 +00:00
Michael Kelley
2e03358be7 Documentation: hyperv: Add overview of guest VM hibernation
Add documentation on how hibernation works in a guest VM on Hyper-V.
Describe how VMBus devices and the VMBus itself are hibernated and
resumed, along with various limitations.

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20250113145645.1320942-1-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250113145645.1320942-1-mhklinux@outlook.com>
2025-01-13 19:17:59 +00:00
Christoph Schlameuss
5021fd77d6 KVM: s390: Reject KVM_SET_GSI_ROUTING on ucontrol VMs
Prevent null pointer dereference when processing
KVM_IRQ_ROUTING_S390_ADAPTER routing entries.
The ioctl cannot be processed for ucontrol VMs.

Fixes: f65470661f ("KVM: s390/interrupt: do not pin adapter interrupt pages")
Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Tested-by: Hariharan Mari <hari55@linux.ibm.com>
Reviewed-by: Hariharan Mari <hari55@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20241216092140.329196-4-schlameuss@linux.ibm.com
Message-ID: <20241216092140.329196-4-schlameuss@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2025-01-07 16:36:11 +01:00
Christoph Schlameuss
df989238fa KVM: s390: Reject setting flic pfault attributes on ucontrol VMs
Prevent null pointer dereference when processing the
KVM_DEV_FLIC_APF_ENABLE and KVM_DEV_FLIC_APF_DISABLE_WAIT ioctls in the
interrupt controller.

Fixes: 3c038e6be0 ("KVM: async_pf: Async page fault support on s390")
Reported-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Reviewed-by: Hariharan Mari <hari55@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20241216092140.329196-2-schlameuss@linux.ibm.com
Message-ID: <20241216092140.329196-2-schlameuss@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2025-01-07 16:36:10 +01:00
Marc Zyngier
affd1c83e0 KVM: arm64: nv: Document EL2 timer API
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20241217142321.763801-13-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-01-02 19:19:10 +00:00
Sean Christopherson
9be4ec35d6 KVM: x86: Advertise TSC_DEADLINE_TIMER in KVM_GET_SUPPORTED_CPUID
Unconditionally advertise TSC_DEADLINE_TIMER via KVM_GET_SUPPORTED_CPUID,
as KVM always emulates deadline mode, *if* the VM has an in-kernel local
APIC.  The odds of a VMM emulating the local APIC in userspace, not
emulating the TSC deadline timer, _and_ reflecting
KVM_GET_SUPPORTED_CPUID back into KVM_SET_CPUID2, i.e. the risk of
over-advertising and breaking any setups, is extremely low.

KVM has _unconditionally_ advertised X2APIC via CPUID since commit
0d1de2d901 ("KVM: Always report x2apic as supported feature"), and it
is completely impossible for userspace to emulate X2APIC as KVM doesn't
support forwarding the MSR accesses to userspace.  I.e. KVM has relied on
userspace VMMs to not misreport local APIC capabilities for nearly 13
years.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20241128013424.4096668-38-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-12-18 14:20:01 -08:00
Sean Christopherson
04cd8f8628 KVM: x86: Disallow KVM_CAP_X86_DISABLE_EXITS after vCPU creation
Reject KVM_CAP_X86_DISABLE_EXITS if vCPUs have been created, as disabling
PAUSE/MWAIT/HLT exits after vCPUs have been created is broken and useless,
e.g. except for PAUSE on SVM, the relevant intercepts aren't updated after
vCPU creation.  vCPUs may also end up with an inconsistent configuration
if exits are disabled between creation of multiple vCPUs.

Cc: Hou Wenlong <houwenlong.hwl@antgroup.com>
Link: https://lore.kernel.org/all/9227068821b275ac547eb2ede09ec65d2281fe07.1680179693.git.houwenlong.hwl@antgroup.com
Link: https://lore.kernel.org/all/20230121020738.2973-2-kechenl@nvidia.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Link: https://lore.kernel.org/r/20241128013424.4096668-14-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-12-18 14:19:35 -08:00
Gianfranco Trad
311cf7164a Documentation: kvm: fix typo in api.rst
Fix minor typo in api.rst where the word physical was misspelled
as physcial.

Signed-off-by: Gianfranco Trad <gianf.trad@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20241115011831.300705-5-gianf.trad@gmail.com
2024-12-11 09:07:40 -07:00
Linus Torvalds
9f16d5e6f2 The biggest change here is eliminating the awful idea that KVM had, of
essentially guessing which pfns are refcounted pages.  The reason to
 do so was that KVM needs to map both non-refcounted pages (for example
 BARs of VFIO devices) and VM_PFNMAP/VM_MIXMEDMAP VMAs that contain
 refcounted pages.  However, the result was security issues in the past,
 and more recently the inability to map VM_IO and VM_PFNMAP memory
 that _is_ backed by struct page but is not refcounted.  In particular
 this broke virtio-gpu blob resources (which directly map host graphics
 buffers into the guest as "vram" for the virtio-gpu device) with the
 amdgpu driver, because amdgpu allocates non-compound higher order pages
 and the tail pages could not be mapped into KVM.
 
 This requires adjusting all uses of struct page in the per-architecture
 code, to always work on the pfn whenever possible.  The large series that
 did this, from David Stevens and Sean Christopherson, also cleaned up
 substantially the set of functions that provided arch code with the
 pfn for a host virtual addresses.  The previous maze of twisty little
 passages, all different, is replaced by five functions (__gfn_to_page,
 __kvm_faultin_pfn, the non-__ versions of these two, and kvm_prefetch_pages)
 saving almost 200 lines of code.
 
 ARM:
 
 * Support for stage-1 permission indirection (FEAT_S1PIE) and
   permission overlays (FEAT_S1POE), including nested virt + the
   emulated page table walker
 
 * Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This call
   was introduced in PSCIv1.3 as a mechanism to request hibernation,
   similar to the S4 state in ACPI
 
 * Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
   part of it, introduce trivial initialization of the host's MPAM
   context so KVM can use the corresponding traps
 
 * PMU support under nested virtualization, honoring the guest
   hypervisor's trap configuration and event filtering when running a
   nested guest
 
 * Fixes to vgic ITS serialization where stale device/interrupt table
   entries are not zeroed when the mapping is invalidated by the VM
 
 * Avoid emulated MMIO completion if userspace has requested synchronous
   external abort injection
 
 * Various fixes and cleanups affecting pKVM, vCPU initialization, and
   selftests
 
 LoongArch:
 
 * Add iocsr and mmio bus simulation in kernel.
 
 * Add in-kernel interrupt controller emulation.
 
 * Add support for virtualization extensions to the eiointc irqchip.
 
 PPC:
 
 * Drop lingering and utterly obsolete references to PPC970 KVM, which was
   removed 10 years ago.
 
 * Fix incorrect documentation references to non-existing ioctls
 
 RISC-V:
 
 * Accelerate KVM RISC-V when running as a guest
 
 * Perf support to collect KVM guest statistics from host side
 
 s390:
 
 * New selftests: more ucontrol selftests and CPU model sanity checks
 
 * Support for the gen17 CPU model
 
 * List registers supported by KVM_GET/SET_ONE_REG in the documentation
 
 x86:
 
 * Cleanup KVM's handling of Accessed and Dirty bits to dedup code, improve
   documentation, harden against unexpected changes.  Even if the hardware
   A/D tracking is disabled, it is possible to use the hardware-defined A/D
   bits to track if a PFN is Accessed and/or Dirty, and that removes a lot
   of special cases.
 
 * Elide TLB flushes when aging secondary PTEs, as has been done in x86's
   primary MMU for over 10 years.
 
 * Recover huge pages in-place in the TDP MMU when dirty page logging is
   toggled off, instead of zapping them and waiting until the page is
   re-accessed to create a huge mapping.  This reduces vCPU jitter.
 
 * Batch TLB flushes when dirty page logging is toggled off.  This reduces
   the time it takes to disable dirty logging by ~3x.
 
 * Remove the shrinker that was (poorly) attempting to reclaim shadow page
   tables in low-memory situations.
 
 * Clean up and optimize KVM's handling of writes to MSR_IA32_APICBASE.
 
 * Advertise CPUIDs for new instructions in Clearwater Forest
 
 * Quirk KVM's misguided behavior of initialized certain feature MSRs to
   their maximum supported feature set, which can result in KVM creating
   invalid vCPU state.  E.g. initializing PERF_CAPABILITIES to a non-zero
   value results in the vCPU having invalid state if userspace hides PDCM
   from the guest, which in turn can lead to save/restore failures.
 
 * Fix KVM's handling of non-canonical checks for vCPUs that support LA57
   to better follow the "architecture", in quotes because the actual
   behavior is poorly documented.  E.g. most MSR writes and descriptor
   table loads ignore CR4.LA57 and operate purely on whether the CPU
   supports LA57.
 
 * Bypass the register cache when querying CPL from kvm_sched_out(), as
   filling the cache from IRQ context is generally unsafe; harden the
   cache accessors to try to prevent similar issues from occuring in the
   future.  The issue that triggered this change was already fixed in 6.12,
   but was still kinda latent.
 
 * Advertise AMD_IBPB_RET to userspace, and fix a related bug where KVM
   over-advertises SPEC_CTRL when trying to support cross-vendor VMs.
 
 * Minor cleanups
 
 * Switch hugepage recovery thread to use vhost_task.  These kthreads can
   consume significant amounts of CPU time on behalf of a VM or in response
   to how the VM behaves (for example how it accesses its memory); therefore
   KVM tried to place the thread in the VM's cgroups and charge the CPU
   time consumed by that work to the VM's container.  However the kthreads
   did not process SIGSTOP/SIGCONT, and therefore cgroups which had KVM
   instances inside could not complete freezing.  Fix this by replacing the
   kthread with a PF_USER_WORKER thread, via the vhost_task abstraction.
   Another 100+ lines removed, with generally better behavior too like
   having these threads properly parented in the process tree.
 
 * Revert a workaround for an old CPU erratum (Nehalem/Westmere) that didn't
   really work; there was really nothing to work around anyway: the broken
   patch was meant to fix nested virtualization, but the PERF_GLOBAL_CTRL
   MSR is virtualized and therefore unaffected by the erratum.
 
 * Fix 6.12 regression where CONFIG_KVM will be built as a module even
   if asked to be builtin, as long as neither KVM_INTEL nor KVM_AMD is 'y'.
 
 x86 selftests:
 
 * x86 selftests can now use AVX.
 
 Documentation:
 
 * Use rST internal links
 
 * Reorganize the introduction to the API document
 
 Generic:
 
 * Protect vcpu->pid accesses outside of vcpu->mutex with a rwlock instead
   of RCU, so that running a vCPU on a different task doesn't encounter long
   due to having to wait for all CPUs become quiescent.  In general both reads
   and writes are rare, but userspace that supports confidential computing is
   introducing the use of "helper" vCPUs that may jump from one host processor
   to another.  Those will be very happy to trigger a synchronize_rcu(), and
   the effect on performance is quite the disaster.
 -----BEGIN PGP SIGNATURE-----
 
 iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmc9MRYUHHBib256aW5p
 QHJlZGhhdC5jb20ACgkQv/vSX3jHroP00QgArxqxBIGLCW5t7bw7vtNq63QYRyh4
 dTiDguLiYQJ+AXmnRu11R6aPC7HgMAvlFCCmH+GEce4WEgt26hxCmncJr/aJOSwS
 letCS7TrME16PeZvh25A1nhPBUw6mTF1qqzgcdHMrqXG8LuHoGcKYGSRVbkf3kfI
 1ZoMq1r8ChXbVVmCx9DQ3gw1TVr5Dpjs2voLh8rDSE9Xpw0tVVabHu3/NhQEz/F+
 t8/nRaqH777icCHIf9PCk5HnarHxLAOvhM2M0Yj09PuBcE5fFQxpxltw/qiKQqqW
 ep4oquojGl87kZnhlDaac2UNtK90Ws+WxxvCwUmbvGN0ZJVaQwf4FvTwig==
 =lWpE
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "The biggest change here is eliminating the awful idea that KVM had of
  essentially guessing which pfns are refcounted pages.

  The reason to do so was that KVM needs to map both non-refcounted
  pages (for example BARs of VFIO devices) and VM_PFNMAP/VM_MIXMEDMAP
  VMAs that contain refcounted pages.

  However, the result was security issues in the past, and more recently
  the inability to map VM_IO and VM_PFNMAP memory that _is_ backed by
  struct page but is not refcounted. In particular this broke virtio-gpu
  blob resources (which directly map host graphics buffers into the
  guest as "vram" for the virtio-gpu device) with the amdgpu driver,
  because amdgpu allocates non-compound higher order pages and the tail
  pages could not be mapped into KVM.

  This requires adjusting all uses of struct page in the
  per-architecture code, to always work on the pfn whenever possible.
  The large series that did this, from David Stevens and Sean
  Christopherson, also cleaned up substantially the set of functions
  that provided arch code with the pfn for a host virtual addresses.

  The previous maze of twisty little passages, all different, is
  replaced by five functions (__gfn_to_page, __kvm_faultin_pfn, the
  non-__ versions of these two, and kvm_prefetch_pages) saving almost
  200 lines of code.

  ARM:

   - Support for stage-1 permission indirection (FEAT_S1PIE) and
     permission overlays (FEAT_S1POE), including nested virt + the
     emulated page table walker

   - Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This
     call was introduced in PSCIv1.3 as a mechanism to request
     hibernation, similar to the S4 state in ACPI

   - Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
     part of it, introduce trivial initialization of the host's MPAM
     context so KVM can use the corresponding traps

   - PMU support under nested virtualization, honoring the guest
     hypervisor's trap configuration and event filtering when running a
     nested guest

   - Fixes to vgic ITS serialization where stale device/interrupt table
     entries are not zeroed when the mapping is invalidated by the VM

   - Avoid emulated MMIO completion if userspace has requested
     synchronous external abort injection

   - Various fixes and cleanups affecting pKVM, vCPU initialization, and
     selftests

  LoongArch:

   - Add iocsr and mmio bus simulation in kernel.

   - Add in-kernel interrupt controller emulation.

   - Add support for virtualization extensions to the eiointc irqchip.

  PPC:

   - Drop lingering and utterly obsolete references to PPC970 KVM, which
     was removed 10 years ago.

   - Fix incorrect documentation references to non-existing ioctls

  RISC-V:

   - Accelerate KVM RISC-V when running as a guest

   - Perf support to collect KVM guest statistics from host side

  s390:

   - New selftests: more ucontrol selftests and CPU model sanity checks

   - Support for the gen17 CPU model

   - List registers supported by KVM_GET/SET_ONE_REG in the
     documentation

  x86:

   - Cleanup KVM's handling of Accessed and Dirty bits to dedup code,
     improve documentation, harden against unexpected changes.

     Even if the hardware A/D tracking is disabled, it is possible to
     use the hardware-defined A/D bits to track if a PFN is Accessed
     and/or Dirty, and that removes a lot of special cases.

   - Elide TLB flushes when aging secondary PTEs, as has been done in
     x86's primary MMU for over 10 years.

   - Recover huge pages in-place in the TDP MMU when dirty page logging
     is toggled off, instead of zapping them and waiting until the page
     is re-accessed to create a huge mapping. This reduces vCPU jitter.

   - Batch TLB flushes when dirty page logging is toggled off. This
     reduces the time it takes to disable dirty logging by ~3x.

   - Remove the shrinker that was (poorly) attempting to reclaim shadow
     page tables in low-memory situations.

   - Clean up and optimize KVM's handling of writes to
     MSR_IA32_APICBASE.

   - Advertise CPUIDs for new instructions in Clearwater Forest

   - Quirk KVM's misguided behavior of initialized certain feature MSRs
     to their maximum supported feature set, which can result in KVM
     creating invalid vCPU state. E.g. initializing PERF_CAPABILITIES to
     a non-zero value results in the vCPU having invalid state if
     userspace hides PDCM from the guest, which in turn can lead to
     save/restore failures.

   - Fix KVM's handling of non-canonical checks for vCPUs that support
     LA57 to better follow the "architecture", in quotes because the
     actual behavior is poorly documented. E.g. most MSR writes and
     descriptor table loads ignore CR4.LA57 and operate purely on
     whether the CPU supports LA57.

   - Bypass the register cache when querying CPL from kvm_sched_out(),
     as filling the cache from IRQ context is generally unsafe; harden
     the cache accessors to try to prevent similar issues from occuring
     in the future. The issue that triggered this change was already
     fixed in 6.12, but was still kinda latent.

   - Advertise AMD_IBPB_RET to userspace, and fix a related bug where
     KVM over-advertises SPEC_CTRL when trying to support cross-vendor
     VMs.

   - Minor cleanups

   - Switch hugepage recovery thread to use vhost_task.

     These kthreads can consume significant amounts of CPU time on
     behalf of a VM or in response to how the VM behaves (for example
     how it accesses its memory); therefore KVM tried to place the
     thread in the VM's cgroups and charge the CPU time consumed by that
     work to the VM's container.

     However the kthreads did not process SIGSTOP/SIGCONT, and therefore
     cgroups which had KVM instances inside could not complete freezing.

     Fix this by replacing the kthread with a PF_USER_WORKER thread, via
     the vhost_task abstraction. Another 100+ lines removed, with
     generally better behavior too like having these threads properly
     parented in the process tree.

   - Revert a workaround for an old CPU erratum (Nehalem/Westmere) that
     didn't really work; there was really nothing to work around anyway:
     the broken patch was meant to fix nested virtualization, but the
     PERF_GLOBAL_CTRL MSR is virtualized and therefore unaffected by the
     erratum.

   - Fix 6.12 regression where CONFIG_KVM will be built as a module even
     if asked to be builtin, as long as neither KVM_INTEL nor KVM_AMD is
     'y'.

  x86 selftests:

   - x86 selftests can now use AVX.

  Documentation:

   - Use rST internal links

   - Reorganize the introduction to the API document

  Generic:

   - Protect vcpu->pid accesses outside of vcpu->mutex with a rwlock
     instead of RCU, so that running a vCPU on a different task doesn't
     encounter long due to having to wait for all CPUs become quiescent.

     In general both reads and writes are rare, but userspace that
     supports confidential computing is introducing the use of "helper"
     vCPUs that may jump from one host processor to another. Those will
     be very happy to trigger a synchronize_rcu(), and the effect on
     performance is quite the disaster"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (298 commits)
  KVM: x86: Break CONFIG_KVM_X86's direct dependency on KVM_INTEL || KVM_AMD
  KVM: x86: add back X86_LOCAL_APIC dependency
  Revert "KVM: VMX: Move LOAD_IA32_PERF_GLOBAL_CTRL errata handling out of setup_vmcs_config()"
  KVM: x86: switch hugepage recovery thread to vhost_task
  KVM: x86: expose MSR_PLATFORM_INFO as a feature MSR
  x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest
  Documentation: KVM: fix malformed table
  irqchip/loongson-eiointc: Add virt extension support
  LoongArch: KVM: Add irqfd support
  LoongArch: KVM: Add PCHPIC user mode read and write functions
  LoongArch: KVM: Add PCHPIC read and write functions
  LoongArch: KVM: Add PCHPIC device support
  LoongArch: KVM: Add EIOINTC user mode read and write functions
  LoongArch: KVM: Add EIOINTC read and write functions
  LoongArch: KVM: Add EIOINTC device support
  LoongArch: KVM: Add IPI user mode read and write function
  LoongArch: KVM: Add IPI read and write function
  LoongArch: KVM: Add IPI device support
  LoongArch: KVM: Add iocsr and mmio bus simulation in kernel
  KVM: arm64: Pass on SVE mapping failures
  ...
2024-11-23 16:00:50 -08:00
Linus Torvalds
0338cd9c22 s390 updates for 6.13 merge window
- Add firmware sysfs interface which allows user space to retrieve the dump
   area size of the machine
 
 - Add 'measurement_chars_full' CHPID sysfs attribute to make the complete
   associated Channel-Measurements Characteristics Block available
 
 - Add virtio-mem support
 
 - Move gmap aka KVM page fault handling from the main fault handler to KVM
   code. This is the first step to make s390 KVM page fault handling similar
   to other architectures. With this first step the main fault handler does
   not have any special handling anymore, and therefore convert it to
   support LOCK_MM_AND_FIND_VMA
 
 - With gcc 14 s390 support for flag output operand support for inline
   assemblies was added. This allows for several optimizations
 
   - Provide a cmpxchg inline assembly which makes use of this, and provide
     all variants of arch_try_cmpxchg() so that the compiler can generate
     slightly better code
 
   - Convert a few cmpxchg() loops to try_cmpxchg() loops
 
   - Similar to x86 add a CC_OUT() helper macro (and other macros), and
     convert all inline assemblies to make use of them, so that depending on
     compiler version better code can be generated
 
 - List installed host-key hashes in sysfs if the machine supports the Query
   Ultravisor Keys UVC
 
 - Add 'Retrieve Secret' ioctl which allows user space in protected
   execution guests to retrieve previously stored secrets from the
   Ultravisor
 
 - Add pkey-uv module which supports the conversion of Ultravisor
   retrievable secrets to protected keys
 
 - Extend the existing paes cipher to exploit the full AES-XTS hardware
   acceleration introduced with message-security assist extension 10
 
 - Convert hopefully all sysfs show functions to use sysfs_emit() so that
   the constant flow of such patches stop
 
 - For PCI devices make use of the newly added Topology ID attribute to
   enable whole card multi-function support despite the change to PCHID per
   port. Additionally improve the overall robustness and usability of
   the multifunction support
 
 - Various other small improvements, fixes, and cleanups
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEECMNfWEw3SLnmiLkZIg7DeRspbsIFAmc3Y9oACgkQIg7DeRsp
 bsJigQ//fcZ3NqA6rARWYoVNEEzUfvDha1LchhAV4aBUu5cIZFc/SQKxMuACVELh
 wW7RKCWhGLML5c/cPjke4ECBJiFYI/MQNB3xkDl1i2FDyUNs1Fdq9Be3Y0uXXO+U
 TxvSYiPm3p/Gik8G2KhDPivqPQmrF7o2KNyRWqPBdqRl5U4NLnwJpCMbddP/PTdI
 2ytJ2OGuXo3djzibXldUbik4UG6hXUqGzeIMbrOG8ZiFCeznVck/OHydoLR4MKBy
 MyrmqCxTu/p7gpTanccpTQR+uC5lodxad4kMh86CV3w41HhrWV1z912eNdsz6MMR
 B8kGPx5D0juXtUbB0Mn0kdM6Kak5/BaSA58HRNJz9AMa5MVOj+YTAmlTN5E7uGzg
 graPE3ilwEgj0pArdhwyhIEnVGP381NyhTbMDhTUhRB6lMJVyN5202YZCieezr/u
 dIyurno1T0T8if1B6n7tQQprIVSQDthzE8lCAtYrll86vLIbiXGxCg2yaVLEz1aL
 ptUZ84/bT29G8XivZAeDLjzRSwde+l5pkZWd3rBmdHC8FCH8Epiy/ZB5ozpJ1u02
 fViqheeTsTC/nR6DlwylF4YET6QVPYgLOUZCnBQJnTsVRFtBpAXIaHyvOJYNuxUN
 ybtsgzJ59bMES8DpBCIibBoJOD1vyoWoeXu06bhGuMT+wahCwgE=
 =v+um
 -----END PGP SIGNATURE-----

Merge tag 's390-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Heiko Carstens:

 - Add firmware sysfs interface which allows user space to retrieve the
   dump area size of the machine

 - Add 'measurement_chars_full' CHPID sysfs attribute to make the
   complete associated Channel-Measurements Characteristics Block
   available

 - Add virtio-mem support

 - Move gmap aka KVM page fault handling from the main fault handler to
   KVM code. This is the first step to make s390 KVM page fault handling
   similar to other architectures. With this first step the main fault
   handler does not have any special handling anymore, and therefore
   convert it to support LOCK_MM_AND_FIND_VMA

 - With gcc 14 s390 support for flag output operand support for inline
   assemblies was added. This allows for several optimizations:

     - Provide a cmpxchg inline assembly which makes use of this, and
       provide all variants of arch_try_cmpxchg() so that the compiler
       can generate slightly better code

     - Convert a few cmpxchg() loops to try_cmpxchg() loops

     - Similar to x86 add a CC_OUT() helper macro (and other macros),
       and convert all inline assemblies to make use of them, so that
       depending on compiler version better code can be generated

 - List installed host-key hashes in sysfs if the machine supports the
   Query Ultravisor Keys UVC

 - Add 'Retrieve Secret' ioctl which allows user space in protected
   execution guests to retrieve previously stored secrets from the
   Ultravisor

 - Add pkey-uv module which supports the conversion of Ultravisor
   retrievable secrets to protected keys

 - Extend the existing paes cipher to exploit the full AES-XTS hardware
   acceleration introduced with message-security assist extension 10

 - Convert hopefully all sysfs show functions to use sysfs_emit() so
   that the constant flow of such patches stop

 - For PCI devices make use of the newly added Topology ID attribute to
   enable whole card multi-function support despite the change to PCHID
   per port. Additionally improve the overall robustness and usability
   of the multifunction support

 - Various other small improvements, fixes, and cleanups

* tag 's390-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (133 commits)
  s390/cio/ioasm: Convert to use flag output macros
  s390/cio/qdio: Convert to use flag output macros
  s390/sclp: Convert to use flag output macros
  s390/dasd: Convert to use flag output macros
  s390/boot/physmem: Convert to use flag output macros
  s390/pci: Convert to use flag output macros
  s390/kvm: Convert to use flag output macros
  s390/extmem: Convert to use flag output macros
  s390/string: Convert to use flag output macros
  s390/diag: Convert to use flag output macros
  s390/irq: Convert to use flag output macros
  s390/smp: Convert to use flag output macros
  s390/uv: Convert to use flag output macros
  s390/pai: Convert to use flag output macros
  s390/mm: Convert to use flag output macros
  s390/cpu_mf: Convert to use flag output macros
  s390/cpcmd: Convert to use flag output macros
  s390/topology: Convert to use flag output macros
  s390/time: Convert to use flag output macros
  s390/pageattr: Convert to use flag output macros
  ...
2024-11-18 17:45:41 -08:00
Paolo Bonzini
7b541d557f KVM/arm64 changes for 6.13, part #1
- Support for stage-1 permission indirection (FEAT_S1PIE) and
    permission overlays (FEAT_S1POE), including nested virt + the
    emulated page table walker
 
  - Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This call
    was introduced in PSCIv1.3 as a mechanism to request hibernation,
    similar to the S4 state in ACPI
 
  - Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
    part of it, introduce trivial initialization of the host's MPAM
    context so KVM can use the corresponding traps
 
  - PMU support under nested virtualization, honoring the guest
    hypervisor's trap configuration and event filtering when running a
    nested guest
 
  - Fixes to vgic ITS serialization where stale device/interrupt table
    entries are not zeroed when the mapping is invalidated by the VM
 
  - Avoid emulated MMIO completion if userspace has requested synchronous
    external abort injection
 
  - Various fixes and cleanups affecting pKVM, vCPU initialization, and
    selftests
 -----BEGIN PGP SIGNATURE-----
 
 iI0EABYIADUWIQSNXHjWXuzMZutrKNKivnWIJHzdFgUCZzTZXRccb2xpdmVyLnVw
 dG9uQGxpbnV4LmRldgAKCRCivnWIJHzdFioUAP0cs2pYcwuCqLgmeHqfz6L5Xsw3
 hKBCNuvr5mjU0hZfLAEA5ml2eUKD7OnssAOmUZ/K/NoCdJFCe8mJWQDlURvr9g4=
 =u2/3
 -----END PGP SIGNATURE-----

Merge tag 'kvmarm-6.13' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 changes for 6.13, part #1

 - Support for stage-1 permission indirection (FEAT_S1PIE) and
   permission overlays (FEAT_S1POE), including nested virt + the
   emulated page table walker

 - Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This call
   was introduced in PSCIv1.3 as a mechanism to request hibernation,
   similar to the S4 state in ACPI

 - Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
   part of it, introduce trivial initialization of the host's MPAM
   context so KVM can use the corresponding traps

 - PMU support under nested virtualization, honoring the guest
   hypervisor's trap configuration and event filtering when running a
   nested guest

 - Fixes to vgic ITS serialization where stale device/interrupt table
   entries are not zeroed when the mapping is invalidated by the VM

 - Avoid emulated MMIO completion if userspace has requested synchronous
   external abort injection

 - Various fixes and cleanups affecting pKVM, vCPU initialization, and
   selftests
2024-11-14 07:05:36 -05:00
Paolo Bonzini
35ff7bfb04 Documentation: KVM: fix malformed table
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 5f6a3badbb ("KVM: x86/mmu: Mark page/folio accessed only when zapping leaf SPTEs")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-13 07:20:01 -05:00
Paolo Bonzini
2e9a2c624e Merge branch 'kvm-docs-6.13' into HEAD
- Drop obsolete references to PPC970 KVM, which was removed 10 years ago.

- Fix incorrect references to non-existing ioctls

- List registers supported by KVM_GET/SET_ONE_REG on s390

- Use rST internal links

- Reorganize the introduction to the API document
2024-11-13 07:18:12 -05:00
Paolo Bonzini
bb4409a9e7 KVM x86 misc changes for 6.13
- Clean up and optimize KVM's handling of writes to MSR_IA32_APICBASE.
 
  - Quirk KVM's misguided behavior of initialized certain feature MSRs to
    their maximum supported feature set, which can result in KVM creating
    invalid vCPU state.  E.g. initializing PERF_CAPABILITIES to a non-zero
    value results in the vCPU having invalid state if userspace hides PDCM
    from the guest, which can lead to save/restore failures.
 
  - Fix KVM's handling of non-canonical checks for vCPUs that support LA57
    to better follow the "architecture", in quotes because the actual
    behavior is poorly documented.  E.g. most MSR writes and descriptor
    table loads ignore CR4.LA57 and operate purely on whether the CPU
    supports LA57.
 
  - Bypass the register cache when querying CPL from kvm_sched_out(), as
    filling the cache from IRQ context is generally unsafe, and harden the
    cache accessors to try to prevent similar issues from occuring in the
    future.
 
  - Advertise AMD_IBPB_RET to userspace, and fix a related bug where KVM
    over-advertises SPEC_CTRL when trying to support cross-vendor VMs.
 
  - Minor cleanups
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEKTobbabEP7vbhhN9OlYIJqCjN/0FAmczowUACgkQOlYIJqCj
 N/3G8w//RYIslQkHXZXovQvhHKM9RBxdg6FjU0Do2KLN/xnR+JdjrBAI3HnG0TVu
 TEsA6slaTdvAFudSBZ27rORPARJ3XCSnDT+NflDR2UqtmGYFXxixcs4LQRUC3I2L
 tS/e847Qfp7/+kXFYQuH6YmMftCf7SQNbUPU3EwSXY8seUJB6ZhO89WXgrBtaMH+
 94b7EdkP86L4dqiEMGr/q/46/ewFpPlB4WWFNIAY+SoZebQ+C8gcAsGDzfG6giNV
 HxdehWNp5nJ34k9Tudt2FseL/IclA3nXZZIl2dU6PWLkjgvDqL2kXLHpAQTpKuXf
 ZzBM4wjdVqZRQHscLgX6+0/uOJDf9/iJs/dwD9PbzLhAJnHF3SWRAy/grzpChLFR
 Yil5zagtdhjqSKDf2FsUCJ7lwaST0fhHvmZZx4loIhcmN0/rvvrhhfLsJgCWv/Kf
 RWMkiSQGhxAZUXjOJDQB+wTHv7ZoJy51ov7/rYjr49jCJrCVO6I6yQ6lNKDCYClR
 vDS3yK6fiEXbC09iudm74FBl2KO+BwJKhnidekzzKGv34RHRAux5Oo54J5jJMhBA
 tXFxALGwKr1KAI7vLK8ByZzwZjN5pDmKHUuOAlJNy9XQi+b4zbbREkXlcqZ5VgxA
 xCibpnLzJFoHS8y7c76wfz4mCkWSWzuC9Rzy4sTkHMzgJESmZiE=
 =dESL
 -----END PGP SIGNATURE-----

Merge tag 'kvm-x86-misc-6.13' of https://github.com/kvm-x86/linux into HEAD

KVM x86 misc changes for 6.13

 - Clean up and optimize KVM's handling of writes to MSR_IA32_APICBASE.

 - Quirk KVM's misguided behavior of initialized certain feature MSRs to
   their maximum supported feature set, which can result in KVM creating
   invalid vCPU state.  E.g. initializing PERF_CAPABILITIES to a non-zero
   value results in the vCPU having invalid state if userspace hides PDCM
   from the guest, which can lead to save/restore failures.

 - Fix KVM's handling of non-canonical checks for vCPUs that support LA57
   to better follow the "architecture", in quotes because the actual
   behavior is poorly documented.  E.g. most MSR writes and descriptor
   table loads ignore CR4.LA57 and operate purely on whether the CPU
   supports LA57.

 - Bypass the register cache when querying CPL from kvm_sched_out(), as
   filling the cache from IRQ context is generally unsafe, and harden the
   cache accessors to try to prevent similar issues from occuring in the
   future.

 - Advertise AMD_IBPB_RET to userspace, and fix a related bug where KVM
   over-advertises SPEC_CTRL when trying to support cross-vendor VMs.

 - Minor cleanups
2024-11-13 06:33:00 -05:00
Oliver Upton
7ccd615bc6 Merge branch kvm-arm64/psci-1.3 into kvmarm/next
* kvm-arm64/psci-1.3:
  : PSCI v1.3 support, courtesy of David Woodhouse
  :
  : Bump KVM's PSCI implementation up to v1.3, with the added bonus of
  : implementing the SYSTEM_OFF2 call. Like other system-scoped PSCI calls,
  : this gets relayed to userspace for further processing with a new
  : KVM_SYSTEM_EVENT_SHUTDOWN flag.
  :
  : As an added bonus, implement client-side support for hibernation with
  : the SYSTEM_OFF2 call.
  arm64: Use SYSTEM_OFF2 PSCI call to power off for hibernate
  KVM: arm64: nvhe: Pass through PSCI v1.3 SYSTEM_OFF2 call
  KVM: selftests: Add test for PSCI SYSTEM_OFF2
  KVM: arm64: Add support for PSCI v1.2 and v1.3
  KVM: arm64: Add PSCI v1.3 SYSTEM_OFF2 function for hibernation
  firmware/psci: Add definitions for PSCI v1.3 specification

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-11-11 18:36:46 +00:00
Paolo Bonzini
5b47f5a725 Documentation: kvm: reorganize introduction
Reorganize the text to mention file descriptors as early as possible.
Also mention capabilities early as they are a central part of KVM's
API.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241023124507.280382-5-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-08 05:57:13 -05:00
Paolo Bonzini
badd5372ec Documentation: kvm: replace section numbers with links
In order to simplify further introduction of hyperlinks, replace explicit
section numbers with rST hyperlinks.  The section numbers could actually
be removed now, but I'm not going to do a huge change throughout the file
for an RFC...

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241023124507.280382-4-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-08 05:57:13 -05:00
Paolo Bonzini
aae7527ea9 Documentation: kvm: fix a few mistakes
The only occurrence "Capability: none" actually meant the same as "basic".
Fix that and a few more aesthetic or content issues in the document.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241023124507.280382-3-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-08 05:57:13 -05:00
Paolo Bonzini
e16e018e82 KVM: powerpc: remove remaining traces of KVM_CAP_PPC_RMA
This was only needed for PPC970 support, which is long gone: the
implementation was removed in 2014.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241023124507.280382-2-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-08 05:57:13 -05:00
David Hildenbrand
e5d94902e4 Documentation: s390-diag.rst: Document diag500(STORAGE LIMIT) subfunction
Let's document our new diag500 subfunction that can be implemented by
userspace.

Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Link: https://lore.kernel.org/r/20241025141453.1210600-3-david@redhat.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07 10:26:24 +01:00
David Hildenbrand
b7cfc04548 Documentation: s390-diag.rst: Make diag500 a generic KVM hypercall
Let's make it a generic KVM hypercall, allowing other subfunctions to
be more independent of virtio.

While at it, document that unsupported/unimplemented subfunctions result
in a SPECIFICATION exception.

This is a preparation for documenting a new subfunction.

Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Link: https://lore.kernel.org/r/20241025141453.1210600-2-david@redhat.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-07 10:26:24 +01:00
Sean Christopherson
dcb988cdac KVM: x86: Quirk initialization of feature MSRs to KVM's max configuration
Add a quirk to control KVM's misguided initialization of select feature
MSRs to KVM's max configuration, as enabling features by default violates
KVM's approach of letting userspace own the vCPU model, and is actively
problematic for MSRs that are conditionally supported, as the vCPU will
end up with an MSR value that userspace can't restore.  E.g. if the vCPU
is configured with PDCM=0, userspace will save and attempt to restore a
non-zero PERF_CAPABILITIES, thanks to KVM's meddling.

Link: https://lore.kernel.org/r/20240802185511.305849-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-11-01 09:22:31 -07:00
Sean Christopherson
0e3b70aa13 KVM: x86: Document an erratum in KVM_SET_VCPU_EVENTS on Intel CPUs
Document a flaw in KVM's ABI which lets userspace attempt to inject a
"bad" hardware exception event, and thus induce VM-Fail on Intel CPUs.
Fixing the flaw is a fool's errand, as AMD doesn't sanity check the
validity of the error code, Intel CPUs that support CET relax the check
for Protected Mode, userspace can change the mode after queueing an
exception, KVM ignores the error code when emulating Real Mode exceptions,
and so on and so forth.

The VM-Fail itself doesn't harm KVM or the kernel beyond triggering a
ratelimited pr_warn(), so just document the oddity.

Link: https://lore.kernel.org/r/20240802200420.330769-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-11-01 09:22:28 -07:00
Sean Christopherson
e2d2ca71ac KVM: Drop @atomic param from gfn=>pfn and hva=>pfn APIs
Drop @atomic from the myriad "to_pfn" APIs now that all callers pass
"false", and remove a comment blurb about KVM running only the "GUP fast"
part in atomic context.

No functional change intended.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241010182427.1434605-13-seanjc@google.com>
2024-10-25 12:57:58 -04:00
Sean Christopherson
5f6a3badbb KVM: x86/mmu: Mark page/folio accessed only when zapping leaf SPTEs
Now that KVM doesn't clobber Accessed bits of shadow-present SPTEs,
e.g. when prefetching, mark folios as accessed only when zapping leaf
SPTEs, which is a rough heuristic for "only in response to an mmu_notifier
invalidation".  Page aging and LRUs are tolerant of false negatives, i.e.
KVM doesn't need to be precise for correctness, and re-marking folios as
accessed when zapping entire roots or when zapping collapsible SPTEs is
expensive and adds very little value.

E.g. when a VM is dying, all of its memory is being freed; marking folios
accessed at that time provides no known value.  Similarly, because KVM
marks folios as accessed when creating SPTEs, marking all folios as
accessed when userspace happens to delete a memslot doesn't add value.
The folio was marked access when the old SPTE was created, and will be
marked accessed yet again if a vCPU accesses the pfn again after reloading
a new root.  Zapping collapsible SPTEs is a similar story; marking folios
accessed just because userspace disable dirty logging is a side effect of
KVM behavior, not a deliberate goal.

As an intermediate step, a.k.a. bisection point, towards *never* marking
folios accessed when dropping SPTEs, mark folios accessed when the primary
MMU might be invalidating mappings, as such zappings are not KVM initiated,
i.e. might actually be related to page aging and LRU activity.

Note, x86 is the only KVM architecture that "double dips"; every other
arch marks pfns as accessed only when mapping into the guest, not when
mapping into the guest _and_ when removing from the guest.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241010182427.1434605-10-seanjc@google.com>
2024-10-25 12:54:42 -04:00
David Woodhouse
97413cea1c KVM: arm64: Add PSCI v1.3 SYSTEM_OFF2 function for hibernation
The PSCI v1.3 specification adds support for a SYSTEM_OFF2 function
which is analogous to ACPI S4 state. This will allow hosting
environments to determine that a guest is hibernated rather than just
powered off, and ensure that they preserve the virtual environment
appropriately to allow the guest to resume safely (or bump the
hardware_signature in the FACS to trigger a clean reboot instead).

This feature is safe to enable unconditionally (in a subsequent commit)
because it is exposed to userspace through the existing
KVM_SYSTEM_EVENT_SHUTDOWN event, just with an additional flag which
userspace can use to know that the instance intended hibernation instead
of a plain power-off.

As with SYSTEM_RESET2, there is only one type available (in this case
HIBERNATE_OFF), and it is not explicitly reported to userspace through
the event; userspace can get it from the registers if it cares).

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Miguel Luis <miguel.luis@oracle.com>
Link: https://lore.kernel.org/r/20241019172459.2241939-3-dwmw2@infradead.org
[oliver: slight cleanup of comments]
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-10-24 16:36:51 -07:00
Sean Christopherson
5a27984244 KVM: x86: Clean up documentation for KVM_X86_QUIRK_SLOT_ZAP_ALL
Massage the documentation for KVM_X86_QUIRK_SLOT_ZAP_ALL to call out that
it applies to moved memslots as well as deleted memslots, to avoid KVM's
"fast zap" terminology (which has no meaning for userspace), and to reword
the documented targeted zap behavior to specifically say that KVM _may_
zap a subset of all SPTEs.  As evidenced by the fix to zap non-leafs SPTEs
with gPTEs, formally documenting KVM's exact internal behavior is risky
and unnecessary.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20241009192345.1148353-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-10-20 07:31:05 -04:00
Dr. David Alan Gilbert
bc07eea2f3 KVM: Remove unused kvm_vcpu_gfn_to_pfn_atomic
The last use of kvm_vcpu_gfn_to_pfn_atomic was removed by commit
1bbc60d0c7 ("KVM: x86/mmu: Remove MMU auditing")

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Message-ID: <20241001141354.18009-3-linux@treblig.org>
[Adjust Documentation/virt/kvm/locking.rst. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-10-20 07:05:51 -04:00
Linus Torvalds
3efc57369a x86:
* KVM currently invalidates the entirety of the page tables, not just
   those for the memslot being touched, when a memslot is moved or deleted.
   The former does not have particularly noticeable overhead, but Intel's
   TDX will require the guest to re-accept private pages if they are
   dropped from the secure EPT, which is a non starter.  Actually,
   the only reason why this is not already being done is a bug which
   was never fully investigated and caused VM instability with assigned
   GeForce GPUs, so allow userspace to opt into the new behavior.
 
 * Advertise AVX10.1 to userspace (effectively prep work for the "real" AVX10
   functionality that is on the horizon).
 
 * Rework common MSR handling code to suppress errors on userspace accesses to
   unsupported-but-advertised MSRs.  This will allow removing (almost?) all of
   KVM's exemptions for userspace access to MSRs that shouldn't exist based on
   the vCPU model (the actual cleanup is non-trivial future work).
 
 * Rework KVM's handling of x2APIC ICR, again, because AMD (x2AVIC) splits the
   64-bit value into the legacy ICR and ICR2 storage, whereas Intel (APICv)
   stores the entire 64-bit value at the ICR offset.
 
 * Fix a bug where KVM would fail to exit to userspace if one was triggered by
   a fastpath exit handler.
 
 * Add fastpath handling of HLT VM-Exit to expedite re-entering the guest when
   there's already a pending wake event at the time of the exit.
 
 * Fix a WARN caused by RSM entering a nested guest from SMM with invalid guest
   state, by forcing the vCPU out of guest mode prior to signalling SHUTDOWN
   (the SHUTDOWN hits the VM altogether, not the nested guest)
 
 * Overhaul the "unprotect and retry" logic to more precisely identify cases
   where retrying is actually helpful, and to harden all retry paths against
   putting the guest into an infinite retry loop.
 
 * Add support for yielding, e.g. to honor NEED_RESCHED, when zapping rmaps in
   the shadow MMU.
 
 * Refactor pieces of the shadow MMU related to aging SPTEs in prepartion for
   adding multi generation LRU support in KVM.
 
 * Don't stuff the RSB after VM-Exit when RETPOLINE=y and AutoIBRS is enabled,
   i.e. when the CPU has already flushed the RSB.
 
 * Trace the per-CPU host save area as a VMCB pointer to improve readability
   and cleanup the retrieval of the SEV-ES host save area.
 
 * Remove unnecessary accounting of temporary nested VMCB related allocations.
 
 * Set FINAL/PAGE in the page fault error code for EPT violations if and only
   if the GVA is valid.  If the GVA is NOT valid, there is no guest-side page
   table walk and so stuffing paging related metadata is nonsensical.
 
 * Fix a bug where KVM would incorrectly synthesize a nested VM-Exit instead of
   emulating posted interrupt delivery to L2.
 
 * Add a lockdep assertion to detect unsafe accesses of vmcs12 structures.
 
 * Harden eVMCS loading against an impossible NULL pointer deref (really truly
   should be impossible).
 
 * Minor SGX fix and a cleanup.
 
 * Misc cleanups
 
 Generic:
 
 * Register KVM's cpuhp and syscore callbacks when enabling virtualization in
   hardware, as the sole purpose of said callbacks is to disable and re-enable
   virtualization as needed.
 
 * Enable virtualization when KVM is loaded, not right before the first VM
   is created.  Together with the previous change, this simplifies a
   lot the logic of the callbacks, because their very existence implies
   virtualization is enabled.
 
 * Fix a bug that results in KVM prematurely exiting to userspace for coalesced
   MMIO/PIO in many cases, clean up the related code, and add a testcase.
 
 * Fix a bug in kvm_clear_guest() where it would trigger a buffer overflow _if_
   the gpa+len crosses a page boundary, which thankfully is guaranteed to not
   happen in the current code base.  Add WARNs in more helpers that read/write
   guest memory to detect similar bugs.
 
 Selftests:
 
 * Fix a goof that caused some Hyper-V tests to be skipped when run on bare
   metal, i.e. NOT in a VM.
 
 * Add a regression test for KVM's handling of SHUTDOWN for an SEV-ES guest.
 
 * Explicitly include one-off assets in .gitignore.  Past Sean was completely
   wrong about not being able to detect missing .gitignore entries.
 
 * Verify userspace single-stepping works when KVM happens to handle a VM-Exit
   in its fastpath.
 
 * Misc cleanups
 -----BEGIN PGP SIGNATURE-----
 
 iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmb201AUHHBib256aW5p
 QHJlZGhhdC5jb20ACgkQv/vSX3jHroOM1gf+Ij7dpCh0KwoNYlHfW2aCHAv3PqQd
 cKMDSGxoCernbJEyPO/3qXNUK+p4zKedk3d92snW3mKa+cwxMdfthJ3i9d7uoNiw
 7hAgcfKNHDZGqAQXhx8QcVF3wgp+diXSyirR+h1IKrGtCCmjMdNC8ftSYe6voEkw
 VTVbLL+tER5H0Xo5UKaXbnXKDbQvWLXkdIqM8dtLGFGLQ2PnF/DdMP0p6HYrKf1w
 B7LBu0rvqYDL8/pS82mtR3brHJXxAr9m72fOezRLEUbfUdzkTUi/b1vEe6nDCl0Q
 i/PuFlARDLWuetlR0VVWKNbop/C/l4EmwCcKzFHa+gfNH3L9361Oz+NzBw==
 =Q7kz
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull x86 kvm updates from Paolo Bonzini:
 "x86:

   - KVM currently invalidates the entirety of the page tables, not just
     those for the memslot being touched, when a memslot is moved or
     deleted.

     This does not traditionally have particularly noticeable overhead,
     but Intel's TDX will require the guest to re-accept private pages
     if they are dropped from the secure EPT, which is a non starter.

     Actually, the only reason why this is not already being done is a
     bug which was never fully investigated and caused VM instability
     with assigned GeForce GPUs, so allow userspace to opt into the new
     behavior.

   - Advertise AVX10.1 to userspace (effectively prep work for the
     "real" AVX10 functionality that is on the horizon)

   - Rework common MSR handling code to suppress errors on userspace
     accesses to unsupported-but-advertised MSRs

     This will allow removing (almost?) all of KVM's exemptions for
     userspace access to MSRs that shouldn't exist based on the vCPU
     model (the actual cleanup is non-trivial future work)

   - Rework KVM's handling of x2APIC ICR, again, because AMD (x2AVIC)
     splits the 64-bit value into the legacy ICR and ICR2 storage,
     whereas Intel (APICv) stores the entire 64-bit value at the ICR
     offset

   - Fix a bug where KVM would fail to exit to userspace if one was
     triggered by a fastpath exit handler

   - Add fastpath handling of HLT VM-Exit to expedite re-entering the
     guest when there's already a pending wake event at the time of the
     exit

   - Fix a WARN caused by RSM entering a nested guest from SMM with
     invalid guest state, by forcing the vCPU out of guest mode prior to
     signalling SHUTDOWN (the SHUTDOWN hits the VM altogether, not the
     nested guest)

   - Overhaul the "unprotect and retry" logic to more precisely identify
     cases where retrying is actually helpful, and to harden all retry
     paths against putting the guest into an infinite retry loop

   - Add support for yielding, e.g. to honor NEED_RESCHED, when zapping
     rmaps in the shadow MMU

   - Refactor pieces of the shadow MMU related to aging SPTEs in
     prepartion for adding multi generation LRU support in KVM

   - Don't stuff the RSB after VM-Exit when RETPOLINE=y and AutoIBRS is
     enabled, i.e. when the CPU has already flushed the RSB

   - Trace the per-CPU host save area as a VMCB pointer to improve
     readability and cleanup the retrieval of the SEV-ES host save area

   - Remove unnecessary accounting of temporary nested VMCB related
     allocations

   - Set FINAL/PAGE in the page fault error code for EPT violations if
     and only if the GVA is valid. If the GVA is NOT valid, there is no
     guest-side page table walk and so stuffing paging related metadata
     is nonsensical

   - Fix a bug where KVM would incorrectly synthesize a nested VM-Exit
     instead of emulating posted interrupt delivery to L2

   - Add a lockdep assertion to detect unsafe accesses of vmcs12
     structures

   - Harden eVMCS loading against an impossible NULL pointer deref
     (really truly should be impossible)

   - Minor SGX fix and a cleanup

   - Misc cleanups

  Generic:

   - Register KVM's cpuhp and syscore callbacks when enabling
     virtualization in hardware, as the sole purpose of said callbacks
     is to disable and re-enable virtualization as needed

   - Enable virtualization when KVM is loaded, not right before the
     first VM is created

     Together with the previous change, this simplifies a lot the logic
     of the callbacks, because their very existence implies
     virtualization is enabled

   - Fix a bug that results in KVM prematurely exiting to userspace for
     coalesced MMIO/PIO in many cases, clean up the related code, and
     add a testcase

   - Fix a bug in kvm_clear_guest() where it would trigger a buffer
     overflow _if_ the gpa+len crosses a page boundary, which thankfully
     is guaranteed to not happen in the current code base. Add WARNs in
     more helpers that read/write guest memory to detect similar bugs

  Selftests:

   - Fix a goof that caused some Hyper-V tests to be skipped when run on
     bare metal, i.e. NOT in a VM

   - Add a regression test for KVM's handling of SHUTDOWN for an SEV-ES
     guest

   - Explicitly include one-off assets in .gitignore. Past Sean was
     completely wrong about not being able to detect missing .gitignore
     entries

   - Verify userspace single-stepping works when KVM happens to handle a
     VM-Exit in its fastpath

   - Misc cleanups"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (127 commits)
  Documentation: KVM: fix warning in "make htmldocs"
  s390: Enable KVM_S390_UCONTROL config in debug_defconfig
  selftests: kvm: s390: Add VM run test case
  KVM: SVM: let alternatives handle the cases when RSB filling is required
  KVM: VMX: Set PFERR_GUEST_{FINAL,PAGE}_MASK if and only if the GVA is valid
  KVM: x86/mmu: Use KVM_PAGES_PER_HPAGE() instead of an open coded equivalent
  KVM: x86/mmu: Add KVM_RMAP_MANY to replace open coded '1' and '1ul' literals
  KVM: x86/mmu: Fold mmu_spte_age() into kvm_rmap_age_gfn_range()
  KVM: x86/mmu: Morph kvm_handle_gfn_range() into an aging specific helper
  KVM: x86/mmu: Honor NEED_RESCHED when zapping rmaps and blocking is allowed
  KVM: x86/mmu: Add a helper to walk and zap rmaps for a memslot
  KVM: x86/mmu: Plumb a @can_yield parameter into __walk_slot_rmaps()
  KVM: x86/mmu: Move walk_slot_rmaps() up near for_each_slot_rmap_range()
  KVM: x86/mmu: WARN on MMIO cache hit when emulating write-protected gfn
  KVM: x86/mmu: Detect if unprotect will do anything based on invalid_list
  KVM: x86/mmu: Subsume kvm_mmu_unprotect_page() into the and_retry() version
  KVM: x86: Rename reexecute_instruction()=>kvm_unprotect_and_retry_on_failure()
  KVM: x86: Update retry protection fields when forcing retry on emulation failure
  KVM: x86: Apply retry protection to "unprotect on failure" path
  KVM: x86: Check EMULTYPE_WRITE_PF_TO_SP before unprotecting gfn
  ...
2024-09-28 09:20:14 -07:00
Linus Torvalds
12cc5240f4 This pull request contains the following changes for UML:
- Removal of dead code (TT mode leftovers, etc.)
 - Fixes for the network vector driver
 - Fixes for time-travel mode
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCAA0FiEEdgfidid8lnn52cLTZvlZhesYu8EFAmb3Bf8WHHJpY2hhcmRA
 c2lnbWEtc3Rhci5hdAAKCRBm+VmF6xi7wZLED/9xfTCB2l8gbiw+vslfXNRKdt6A
 jcqC4MfZ/dxkt5X2iy9pGROBl0dRe2WAbdSJIBIQikVDaTWg4Vix7WcnMs+FTXxk
 gGlJU8xx69mh7MWH0DopJrCHYX1SxA4bxve4J7iljTzuMleYhUUJ6bdqmG9XBRBN
 M1hYWpAodR/BPaDRZtLpzdYuuo3cZPM3ESpke5GupsFEWxqRZqvdlgwdsb9RfrOe
 3HvWZUMrw+hWJg1NkQ7+ljqPjoaafGu8/ic89r44bNtNQqN+o5b1v1E792e9qCJD
 1jRXTQMtTDH+ETgYskzWEIFyMQ4WlRy/N+mKKUHUJrTwAm76zdSpxmvU2Fh8cvLy
 ofWdbtqR127WnKii7UpZLf6kXzmC6pcmLbHU78PohoOnEjk4TeMjEKw6FrcSZY51
 wGgz29mLJOZ33mh7So37bRU/x5OKkq0u+BHyrhZYiHXdcBN8R5KBSJlWvl+A+A7y
 F5VpUvqAazc6H0HazZDWtoPDJ4HpbSEbH/8G4rR3IlZ4DmqyRuOr6f4AeiEPFz2n
 VNQVivgFL59zPflo8eWsLQvK8ZaZSop05RDYRk53uMooUZUNKvhTFmIRCb6bNFT/
 c4Ycoi3qa+YQQxSUEKmrE71dOYxdT1nHvl7YgR0BGABWYt2G1j/UyTjJMJ7L49Ws
 HGpAnI4FdPELu3qIVA==
 =DHl2
 -----END PGP SIGNATURE-----

Merge tag 'uml-for-linus-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux

Pull UML updates from Richard Weinberger:

 - Removal of dead code (TT mode leftovers, etc)

 - Fixes for the network vector driver

 - Fixes for time-travel mode

* tag 'uml-for-linus-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux:
  um: fix time-travel syscall scheduling hack
  um: Remove outdated asm/sysrq.h header
  um: Remove the declaration of user_thread function
  um: Remove the call to SUBARCH_EXECVE1 macro
  um: Remove unused mm_fd field from mm_id
  um: Remove unused fields from thread_struct
  um: Remove the redundant newpage check in update_pte_range
  um: Remove unused kpte_clear_flush macro
  um: Remove obsoleted declaration for execute_syscall_skas
  user_mode_linux_howto_v2: add VDE vector support in doc
  vector_user: add VDE support
  um: remove ARCH_NO_PREEMPT_DYNAMIC
  um: vector: Fix NAPI budget handling
  um: vector: Replace locks guarding queue depth with atomics
  um: remove variable stack array in os_rcv_fd_msg()
2024-09-27 12:48:48 -07:00
Paolo Bonzini
efbc6bd090 Documentation: KVM: fix warning in "make htmldocs"
The warning

 Documentation/virt/kvm/locking.rst:31: ERROR: Unexpected indentation.

is caused by incorrectly treating a line as the continuation of a paragraph,
rather than as the first line in a bullet list.

Fixed: 44d1745962 ("KVM: Use dedicated mutex to protect kvm_usage_count to avoid deadlock")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-09-27 11:45:50 -04:00
Paolo Bonzini
3f8df62852 Merge tag 'kvm-x86-vmx-6.12' of https://github.com/kvm-x86/linux into HEAD
KVM VMX changes for 6.12:

 - Set FINAL/PAGE in the page fault error code for EPT Violations if and only
   if the GVA is valid.  If the GVA is NOT valid, there is no guest-side page
   table walk and so stuffing paging related metadata is nonsensical.

 - Fix a bug where KVM would incorrectly synthesize a nested VM-Exit instead of
   emulating posted interrupt delivery to L2.

 - Add a lockdep assertion to detect unsafe accesses of vmcs12 structures.

 - Harden eVMCS loading against an impossible NULL pointer deref (really truly
   should be impossible).

 - Minor SGX fix and a cleanup.
2024-09-17 12:41:23 -04:00
Linus Torvalds
d58db3f3a0 Another relatively mundane cycle for docs:
- The beginning of an EEVDF scheduler document
 
 - More Chinese translations
 
 - A rethrashing of our bisection documentation
 
 ...plus the usual array of smaller fixes, and more than the usual number of
 typo fixes.
 -----BEGIN PGP SIGNATURE-----
 
 iQEzBAABCAAdFiEEIw+MvkEiF49krdp9F0NaE2wMflgFAmboMnkACgkQF0NaE2wM
 flha/Qf/e8zRinIYQJ7BmombNm39w3wUiNuXr8SWq7afqhsAJJzmOZ3oyyfssL+B
 a1pSjhxb15UrKf1kMKhdBxhDndXvto5UekJRBY5gsTvcBMBmtIovN+ZK5Z5jObsw
 gzHD9of08Ti7N4C2dSBdLPHtvIBX0rVeEK4oAH7AUaQviu1cfTaLQQA0dRYsaJeX
 iXsts2NkGl6ZUF7mk4nlzj8+Y1zot+mCd6B53iSimNKxwsPODrCZUobJAvxg1qVU
 pRCQcnpx2fTBnh4ugrcLZbautyhL9bJ8VQzFeoQgYpODDgDnZyTjN6kxv65LpxAz
 dXi+hx5Vk7lP3BbTp9EeGn305/qQPA==
 =JuBw
 -----END PGP SIGNATURE-----

Merge tag 'docs-6.12' of git://git.lwn.net/linux

Pull documentation update from Jonathan Corbet:
 "Another relatively mundane cycle for docs:

   - The beginning of an EEVDF scheduler document

   - More Chinese translations

   - A rethrashing of our bisection documentation

  ...plus the usual array of smaller fixes, and more than the usual
  number of typo fixes"

* tag 'docs-6.12' of git://git.lwn.net/linux: (48 commits)
  Remove duplicate "and" in 'Linux NVMe docs.
  docs:filesystems: fix spelling and grammar mistakes
  docs:filesystem: fix mispelled words on autofs page
  docs:mm: fixed spelling and grammar mistakes on vmalloc kernel stack page
  Documentation: PCI: fix typo in pci.rst
  docs/zh_CN: add the translation of kbuild/gcc-plugins.rst
  docs/process: fix typos
  docs:mm: fix spelling mistakes in heterogeneous memory management page
  accel/qaic: Fix a typo
  docs/zh_CN: update the translation of security-bugs
  docs: block: Fix grammar and spelling mistakes in bfq-iosched.rst
  Documentation: Fix spelling mistakes
  Documentation/gpu: Fix typo in Documentation/gpu/komeda-kms.rst
  scripts: sphinx-pre-install: remove unnecessary double check for $cur_version
  Loongarch: KVM: Add KVM hypercalls documentation for LoongArch
  Documentation: Document the kernel flag bdev_allow_write_mounted
  docs: scheduler: completion: Update member of struct completion
  docs: kerneldoc-preamble.sty: Suppress extra spaces in CJK literal blocks
  docs: submitting-patches: Advertise b4
  docs: update dev-tools/kcsan.rst url about KTSAN
  ...
2024-09-17 16:44:08 +02:00
Linus Torvalds
114143a595 arm64 updates for 6.12
ACPI:
 * Enable PMCG erratum workaround for HiSilicon HIP10 and 11 platforms.
 * Ensure arm64-specific IORT header is covered by MAINTAINERS.
 
 CPU Errata:
 * Enable workaround for hardware access/dirty issue on Ampere-1A cores.
 
 Memory management:
 * Define PHYSMEM_END to fix a crash in the amdgpu driver.
 * Avoid tripping over invalid kernel mappings on the kexec() path.
 * Userspace support for the Permission Overlay Extension (POE) using
   protection keys.
 
 Perf and PMUs:
 * Add support for the "fixed instruction counter" extension in the CPU
   PMU architecture.
 * Extend and fix the event encodings for Apple's M1 CPU PMU.
 * Allow LSM hooks to decide on SPE permissions for physical profiling.
 * Add support for the CMN S3 and NI-700 PMUs.
 
 Confidential Computing:
 * Add support for booting an arm64 kernel as a protected guest under
   Android's "Protected KVM" (pKVM) hypervisor.
 
 Selftests:
 * Fix vector length issues in the SVE/SME sigreturn tests
 * Fix build warning in the ptrace tests.
 
 Timers:
 * Add support for PR_{G,S}ET_TSC so that 'rr' can deal with
   non-determinism arising from the architected counter.
 
 Miscellaneous:
 * Rework our IPI-based CPU stopping code to try NMIs if regular IPIs
   don't succeed.
 * Minor fixes and cleanups.
 -----BEGIN PGP SIGNATURE-----
 
 iQFEBAABCgAuFiEEPxTL6PPUbjXGY88ct6xw3ITBYzQFAmbkVNEQHHdpbGxAa2Vy
 bmVsLm9yZwAKCRC3rHDchMFjNKeIB/9YtbN7JMgsXktM94GP03r3tlFF36Y1S51S
 +zdDZclAVZCTCZN+PaFeAZ/+ah2EQYrY6rtDoHUSEMQdF9kH+ycuIPDTwaJ4Qkam
 QKXMpAgtY/4yf2rX4lhDF8rEvkhLDsu7oGDhqUZQsA33GrMBHfgA3oqpYwlVjvGq
 gkm7olTo9LdWAxkPpnjGrjB6Mv5Dq8dJRhW+0Q5AntI5zx3RdYGJZA9GUSzyYCCt
 FIYOtMmWPkQ0kKxIVxOxAOm/ubhfyCs2sjSfkaa3vtvtt+Yjye1Xd81rFciIbPgP
 QlK/Mes2kBZmjhkeus8guLI5Vi7tx3DQMkNqLXkHAAzOoC4oConE
 =6osL
 -----END PGP SIGNATURE-----

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "The highlights are support for Arm's "Permission Overlay Extension"
  using memory protection keys, support for running as a protected guest
  on Android as well as perf support for a bunch of new interconnect
  PMUs.

  Summary:

  ACPI:
   - Enable PMCG erratum workaround for HiSilicon HIP10 and 11
     platforms.
   - Ensure arm64-specific IORT header is covered by MAINTAINERS.

  CPU Errata:
   - Enable workaround for hardware access/dirty issue on Ampere-1A
     cores.

  Memory management:
   - Define PHYSMEM_END to fix a crash in the amdgpu driver.
   - Avoid tripping over invalid kernel mappings on the kexec() path.
   - Userspace support for the Permission Overlay Extension (POE) using
     protection keys.

  Perf and PMUs:
   - Add support for the "fixed instruction counter" extension in the
     CPU PMU architecture.
   - Extend and fix the event encodings for Apple's M1 CPU PMU.
   - Allow LSM hooks to decide on SPE permissions for physical
     profiling.
   - Add support for the CMN S3 and NI-700 PMUs.

  Confidential Computing:
   - Add support for booting an arm64 kernel as a protected guest under
     Android's "Protected KVM" (pKVM) hypervisor.

  Selftests:
   - Fix vector length issues in the SVE/SME sigreturn tests
   - Fix build warning in the ptrace tests.

  Timers:
   - Add support for PR_{G,S}ET_TSC so that 'rr' can deal with
     non-determinism arising from the architected counter.

  Miscellaneous:
   - Rework our IPI-based CPU stopping code to try NMIs if regular IPIs
     don't succeed.
   - Minor fixes and cleanups"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (94 commits)
  perf: arm-ni: Fix an NULL vs IS_ERR() bug
  arm64: hibernate: Fix warning for cast from restricted gfp_t
  arm64: esr: Define ESR_ELx_EC_* constants as UL
  arm64: pkeys: remove redundant WARN
  perf: arm_pmuv3: Use BR_RETIRED for HW branch event if enabled
  MAINTAINERS: List Arm interconnect PMUs as supported
  perf: Add driver for Arm NI-700 interconnect PMU
  dt-bindings/perf: Add Arm NI-700 PMU
  perf/arm-cmn: Improve format attr printing
  perf/arm-cmn: Clean up unnecessary NUMA_NO_NODE check
  arm64/mm: use lm_alias() with addresses passed to memblock_free()
  mm: arm64: document why pte is not advanced in contpte_ptep_set_access_flags()
  arm64: Expose the end of the linear map in PHYSMEM_END
  arm64: trans_pgd: mark PTEs entries as valid to avoid dead kexec()
  arm64/mm: Delete __init region from memblock.reserved
  perf/arm-cmn: Support CMN S3
  dt-bindings: perf: arm-cmn: Add CMN S3
  perf/arm-cmn: Refactor DTC PMU register access
  perf/arm-cmn: Make cycle counts less surprising
  perf/arm-cmn: Improve build-time assertion
  ...
2024-09-16 06:55:07 +02:00
Renzo Davoli
cccf19f8b5 user_mode_linux_howto_v2: add VDE vector support in doc
Add a description of the VDE vector transport in user_mode_linux_howto_v2.rst.

Signed-off-by: Renzo Davoli <renzo@cs.unibo.it>
Signed-off-by: Renzo Davoi <renzo@cs.unibo.it>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-09-12 20:18:51 +02:00
Linus Torvalds
fb92a1ffc1 hyperv-fixes for 6.11-rc8
-----BEGIN PGP SIGNATURE-----
 
 iQFHBAABCgAxFiEEIbPD0id6easf0xsudhRwX5BBoF4FAmbeRpsTHHdlaS5saXVA
 a2VybmVsLm9yZwAKCRB2FHBfkEGgXsDDB/4oL6ypxiF3/yo+xR6bt8HlzIfcVeTx
 EuDR+a/hDRQdShMbNtgaF2OxovMO1W5Se2hCoNrKbVxrPRHL6gUuZASdm93l75eh
 l8I0muQif1q9rEXNbwQxe/ydE0860OgmE/ZGv944BXBtirG1fGHei1DNKkdL6VJy
 iEmmURwz7Ykg5neqwzYBY9SV7P/wwWZNR8GIRTWHhWU+ok1cYpehAs1dpQleAxsz
 WZCQLfIMXdSJBSDB/YO7JAlykZ1DkkTkI8pfbe2diReaDSw2QYsnsPXD6MVZArLO
 73kDojwb0LitLyWYEjm07ipOApkzYrEGTXjlLNdUVVF1Fx20nohu8jRd
 =k5P6
 -----END PGP SIGNATURE-----

Merge tag 'hyperv-fixes-signed-20240908' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv fixes from Wei Liu:

 - Add a documentation overview of Confidential Computing VM support
   (Michael Kelley)

 - Use lapic timer in a TDX VM without paravisor (Dexuan Cui)

 - Set X86_FEATURE_TSC_KNOWN_FREQ when Hyper-V provides frequency
   (Michael Kelley)

 - Fix a kexec crash due to VP assist page corruption (Anirudh
   Rayabharam)

 - Python3 compatibility fix for lsvmbus (Anthony Nandaa)

 - Misc fixes (Rachel Menge, Roman Kisel, zhang jiao, Hongbo Li)

* tag 'hyperv-fixes-signed-20240908' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hv: vmbus: Constify struct kobj_type and struct attribute_group
  tools: hv: rm .*.cmd when make clean
  x86/hyperv: fix kexec crash due to VP assist page corruption
  Drivers: hv: vmbus: Fix the misplaced function description
  tools: hv: lsvmbus: change shebang to use python3
  x86/hyperv: Set X86_FEATURE_TSC_KNOWN_FREQ when Hyper-V provides frequency
  Documentation: hyperv: Add overview of Confidential Computing VM support
  clocksource: hyper-v: Use lapic timer in a TDX VM without paravisor
  Drivers: hv: Remove deprecated hv_fcopy declarations
2024-09-09 09:31:55 -07:00
Bibo Mao
bc6cb62007 Loongarch: KVM: Add KVM hypercalls documentation for LoongArch
Add documentation topic for using pv_virt when running as a guest
on KVM hypervisor.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Xianglai Li <lixianglai@loongson.cn>
Co-developed-by: Mingcong Bai <jeffbai@aosc.io>
Signed-off-by: Mingcong Bai <jeffbai@aosc.io>
Link: https://lore.kernel.org/all/5c338084b1bcccc1d57dce9ddb1e7081@aosc.io/
Signed-off-by: Dandan Zhang <zhangdandan@uniontech.com>
[jc: fixed htmldocs build error]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/4769C036576F8816+20240828045950.3484113-1-zhangdandan@uniontech.com
2024-09-05 14:30:35 -06:00
Sean Christopherson
9a798b1337 KVM: Register cpuhp and syscore callbacks when enabling hardware
Register KVM's cpuhp and syscore callback when enabling virtualization
in hardware instead of registering the callbacks during initialization,
and let the CPU up/down framework invoke the inner enable/disable
functions.  Registering the callbacks during initialization makes things
more complex than they need to be, as KVM needs to be very careful about
handling races between enabling CPUs being onlined/offlined and hardware
being enabled/disabled.

Intel TDX support will require KVM to enable virtualization during KVM
initialization, i.e. will add another wrinkle to things, at which point
sorting out the potential races with kvm_usage_count would become even
more complex.

Note, using the cpuhp framework has a subtle behavioral change: enabling
will be done serially across all CPUs, whereas KVM currently sends an IPI
to all CPUs in parallel.  While serializing virtualization enabling could
create undesirable latency, the issue is limited to the 0=>1 transition of
VM creation.  And even that can be mitigated, e.g. by letting userspace
force virtualization to be enabled when KVM is initialized.

Cc: Chao Gao <chao.gao@intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Acked-by: Kai Huang <kai.huang@intel.com>
Tested-by: Farrah Chen <farrah.chen@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20240830043600.127750-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-09-04 11:02:33 -04:00
Sean Christopherson
44d1745962 KVM: Use dedicated mutex to protect kvm_usage_count to avoid deadlock
Use a dedicated mutex to guard kvm_usage_count to fix a potential deadlock
on x86 due to a chain of locks and SRCU synchronizations.  Translating the
below lockdep splat, CPU1 #6 will wait on CPU0 #1, CPU0 #8 will wait on
CPU2 #3, and CPU2 #7 will wait on CPU1 #4 (if there's a writer, due to the
fairness of r/w semaphores).

    CPU0                     CPU1                     CPU2
1   lock(&kvm->slots_lock);
2                                                     lock(&vcpu->mutex);
3                                                     lock(&kvm->srcu);
4                            lock(cpu_hotplug_lock);
5                            lock(kvm_lock);
6                            lock(&kvm->slots_lock);
7                                                     lock(cpu_hotplug_lock);
8   sync(&kvm->srcu);

Note, there are likely more potential deadlocks in KVM x86, e.g. the same
pattern of taking cpu_hotplug_lock outside of kvm_lock likely exists with
__kvmclock_cpufreq_notifier():

  cpuhp_cpufreq_online()
  |
  -> cpufreq_online()
     |
     -> cpufreq_gov_performance_limits()
        |
        -> __cpufreq_driver_target()
           |
           -> __target_index()
              |
              -> cpufreq_freq_transition_begin()
                 |
                 -> cpufreq_notify_transition()
                    |
                    -> ... __kvmclock_cpufreq_notifier()

But, actually triggering such deadlocks is beyond rare due to the
combination of dependencies and timings involved.  E.g. the cpufreq
notifier is only used on older CPUs without a constant TSC, mucking with
the NX hugepage mitigation while VMs are running is very uncommon, and
doing so while also onlining/offlining a CPU (necessary to generate
contention on cpu_hotplug_lock) would be even more unusual.

The most robust solution to the general cpu_hotplug_lock issue is likely
to switch vm_list to be an RCU-protected list, e.g. so that x86's cpufreq
notifier doesn't to take kvm_lock.  For now, settle for fixing the most
blatant deadlock, as switching to an RCU-protected list is a much more
involved change, but add a comment in locking.rst to call out that care
needs to be taken when walking holding kvm_lock and walking vm_list.

  ======================================================
  WARNING: possible circular locking dependency detected
  6.10.0-smp--c257535a0c9d-pip #330 Tainted: G S         O
  ------------------------------------------------------
  tee/35048 is trying to acquire lock:
  ff6a80eced71e0a8 (&kvm->slots_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x179/0x1e0 [kvm]

  but task is already holding lock:
  ffffffffc07abb08 (kvm_lock){+.+.}-{3:3}, at: set_nx_huge_pages+0x14a/0x1e0 [kvm]

  which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

  -> #3 (kvm_lock){+.+.}-{3:3}:
         __mutex_lock+0x6a/0xb40
         mutex_lock_nested+0x1f/0x30
         kvm_dev_ioctl+0x4fb/0xe50 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> #2 (cpu_hotplug_lock){++++}-{0:0}:
         cpus_read_lock+0x2e/0xb0
         static_key_slow_inc+0x16/0x30
         kvm_lapic_set_base+0x6a/0x1c0 [kvm]
         kvm_set_apic_base+0x8f/0xe0 [kvm]
         kvm_set_msr_common+0x9ae/0xf80 [kvm]
         vmx_set_msr+0xa54/0xbe0 [kvm_intel]
         __kvm_set_msr+0xb6/0x1a0 [kvm]
         kvm_arch_vcpu_ioctl+0xeca/0x10c0 [kvm]
         kvm_vcpu_ioctl+0x485/0x5b0 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> #1 (&kvm->srcu){.+.+}-{0:0}:
         __synchronize_srcu+0x44/0x1a0
         synchronize_srcu_expedited+0x21/0x30
         kvm_swap_active_memslots+0x110/0x1c0 [kvm]
         kvm_set_memslot+0x360/0x620 [kvm]
         __kvm_set_memory_region+0x27b/0x300 [kvm]
         kvm_vm_ioctl_set_memory_region+0x43/0x60 [kvm]
         kvm_vm_ioctl+0x295/0x650 [kvm]
         __se_sys_ioctl+0x7b/0xd0
         __x64_sys_ioctl+0x21/0x30
         x64_sys_call+0x15d0/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

  -> #0 (&kvm->slots_lock){+.+.}-{3:3}:
         __lock_acquire+0x15ef/0x2e30
         lock_acquire+0xe0/0x260
         __mutex_lock+0x6a/0xb40
         mutex_lock_nested+0x1f/0x30
         set_nx_huge_pages+0x179/0x1e0 [kvm]
         param_attr_store+0x93/0x100
         module_attr_store+0x22/0x40
         sysfs_kf_write+0x81/0xb0
         kernfs_fop_write_iter+0x133/0x1d0
         vfs_write+0x28d/0x380
         ksys_write+0x70/0xe0
         __x64_sys_write+0x1f/0x30
         x64_sys_call+0x281b/0x2e60
         do_syscall_64+0x83/0x160
         entry_SYSCALL_64_after_hwframe+0x76/0x7e

Cc: Chao Gao <chao.gao@intel.com>
Fixes: 0bf50497f0 ("KVM: Drop kvm_count_lock and instead protect kvm_usage_count with kvm_lock")
Cc: stable@vger.kernel.org
Reviewed-by: Kai Huang <kai.huang@intel.com>
Acked-by: Kai Huang <kai.huang@intel.com>
Tested-by: Farrah Chen <farrah.chen@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20240830043600.127750-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-09-04 11:02:33 -04:00
Will Deacon
0f12694958 drivers/virt: pkvm: Intercept ioremap using pKVM MMIO_GUARD hypercall
Hook up pKVM's MMIO_GUARD hypercall so that ioremap() and friends will
register the target physical address as MMIO with the hypervisor,
allowing guest exits to that page to be emulated by the host with full
syndrome information.

Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240830130150.8568-7-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2024-08-30 16:30:41 +01:00
Will Deacon
ebc59b120c drivers/virt: pkvm: Hook up mem_encrypt API using pKVM hypercalls
If we detect the presence of pKVM's SHARE and UNSHARE hypercalls, then
register a backend implementation of the mem_encrypt API so that things
like DMA buffers can be shared appropriately with the host.

Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240830130150.8568-5-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2024-08-30 16:30:41 +01:00
Will Deacon
a06c3fad49 drivers/virt: pkvm: Add initial support for running as a protected guest
Implement a pKVM protected guest driver to probe the presence of pKVM
and determine the memory protection granule using the HYP_MEMINFO
hypercall.

Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240830130150.8568-3-will@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2024-08-30 16:30:41 +01:00
Sean Christopherson
653ea4489e KVM: nVMX: Honor userspace MSR filter lists for nested VM-Enter/VM-Exit
Synthesize a consistency check VM-Exit (VM-Enter) or VM-Abort (VM-Exit) if
L1 attempts to load/store an MSR via the VMCS MSR lists that userspace has
disallowed access to via an MSR filter.  Intel already disallows including
a handful of "special" MSRs in the VMCS lists, so denying access isn't
completely without precedent.

More importantly, the behavior is well-defined _and_ can be communicated
the end user, e.g. to the customer that owns a VM running as L1 on top of
KVM.  On the other hand, ignoring userspace MSR filters is all but
guaranteed to result in unexpected behavior as the access will hit KVM's
internal state, which is likely not up-to-date.

Unlike KVM-internal accesses, instruction emulation, and dedicated VMCS
fields, the MSRs in the VMCS load/store lists are 100% guest controlled,
thus making it all but impossible to reason about the correctness of
ignoring the MSR filter.  And if userspace *really* wants to deny access
to MSRs via the aforementioned scenarios, userspace can hide the
associated feature from the guest, e.g. by disabling the PMU to prevent
accessing PERF_GLOBAL_CTRL via its VMCS field.  But for the MSR lists, KVM
is blindly processing MSRs; the  MSR filters are the _only_ way for
userspace to deny access.

This partially reverts commit ac8d6cad3c ("KVM: x86: Only do MSR
filtering when access MSR by rdmsr/wrmsr").

Cc: Hou Wenlong <houwenlong.hwl@antgroup.com>
Cc: Jim Mattson <jmattson@google.com>
Link: https://lore.kernel.org/r/20240722235922.3351122-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-08-22 11:35:16 -07:00
Yan Zhao
aa8d1f48d3 KVM: x86/mmu: Introduce a quirk to control memslot zap behavior
Introduce the quirk KVM_X86_QUIRK_SLOT_ZAP_ALL to allow users to select
KVM's behavior when a memslot is moved or deleted for KVM_X86_DEFAULT_VM
VMs. Make sure KVM behave as if the quirk is always disabled for
non-KVM_X86_DEFAULT_VM VMs.

The KVM_X86_QUIRK_SLOT_ZAP_ALL quirk offers two behavior options:
- when enabled:  Invalidate/zap all SPTEs ("zap-all"),
- when disabled: Precisely zap only the leaf SPTEs within the range of the
                 moving/deleting memory slot ("zap-slot-leafs-only").

"zap-all" is today's KVM behavior to work around a bug [1] where the
changing the zapping behavior of memslot move/deletion would cause VM
instability for VMs with an Nvidia GPU assigned; while
"zap-slot-leafs-only" allows for more precise zapping of SPTEs within the
memory slot range, improving performance in certain scenarios [2], and
meeting the functional requirements for TDX.

Previous attempts to select "zap-slot-leafs-only" include a per-VM
capability approach [3] (which was not preferred because the root cause of
the bug remained unidentified) and a per-memslot flag approach [4]. Sean
and Paolo finally recommended the implementation of this quirk and
explained that it's the least bad option [5].

By default, the quirk is enabled on KVM_X86_DEFAULT_VM VMs to use
"zap-all". Users have the option to disable the quirk to select
"zap-slot-leafs-only" for specific KVM_X86_DEFAULT_VM VMs that are
unaffected by this bug.

For non-KVM_X86_DEFAULT_VM VMs, the "zap-slot-leafs-only" behavior is
always selected without user's opt-in, regardless of if the user opts for
"zap-all".
This is because it is assumed until proven otherwise that non-
KVM_X86_DEFAULT_VM VMs will not be exposed to the bug [1], and most
importantly, it's because TDX must have "zap-slot-leafs-only" always
selected. In TDX's case a memslot's GPA range can be a mixture of "private"
or "shared" memory. Shared is roughly analogous to how EPT is handled for
normal VMs, but private GPAs need lots of special treatment:
1) "zap-all" would require to zap private root page or non-leaf entries or
   at least leaf-entries beyond the deleting memslot scope. However, TDX
   demands that the root page of the private page table remains unchanged,
   with leaf entries being zapped before non-leaf entries, and any dropped
   private guest pages must be re-accepted by the guest.
2) if "zap-all" zaps only shared page tables, it would result in private
   pages still being mapped when the memslot is gone. This may affect even
   other processes if later the gmem fd was whole punched, causing the
   pages being freed on the host while still mapped in the TD, because
   there's no pgoff to the gfn information to zap the private page table
   after memslot is gone.

So, simply go "zap-slot-leafs-only" as if the quirk is always disabled for
non-KVM_X86_DEFAULT_VM VMs to avoid manual opt-in for every VM type [6] or
complicating quirk disabling interface (current quirk disabling interface
is limited, no way to query quirks, or force them to be disabled).

Add a new function kvm_mmu_zap_memslot_leafs() to implement
"zap-slot-leafs-only". This function does not call kvm_unmap_gfn_range(),
bypassing special handling to APIC_ACCESS_PAGE_PRIVATE_MEMSLOT, as
1) The APIC_ACCESS_PAGE_PRIVATE_MEMSLOT cannot be created by users, nor can
   it be moved. It is only deleted by KVM when APICv is permanently
   inhibited.
2) kvm_vcpu_reload_apic_access_page() effectively does nothing when
   APIC_ACCESS_PAGE_PRIVATE_MEMSLOT is deleted.
3) Avoid making all cpus request of KVM_REQ_APIC_PAGE_RELOAD can save on
   costly IPIs.

Suggested-by: Kai Huang <kai.huang@intel.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://patchwork.kernel.org/project/kvm/patch/20190205210137.1377-11-sean.j.christopherson@intel.com [1]
Link: https://patchwork.kernel.org/project/kvm/patch/20190205210137.1377-11-sean.j.christopherson@intel.com/#25054908 [2]
Link: https://lore.kernel.org/kvm/20200713190649.GE29725@linux.intel.com/T/#mabc0119583dacf621025e9d873c85f4fbaa66d5c [3]
Link: https://lore.kernel.org/all/20240515005952.3410568-3-rick.p.edgecombe@intel.com [4]
Link: https://lore.kernel.org/all/7df9032d-83e4-46a1-ab29-6c7973a2ab0b@redhat.com [5]
Link: https://lore.kernel.org/all/ZnGa550k46ow2N3L@google.com [6]
Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20240703021043.13881-1-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-08-14 12:29:11 -04:00
Paolo Bonzini
747cfbf161 KVM/arm64 fixes for 6.11, round #1
- Use kvfree() for the kvmalloc'd nested MMUs array
 
  - Set of fixes to address warnings in W=1 builds
 
  - Make KVM depend on assembler support for ARMv8.4
 
  - Fix for vgic-debug interface for VMs without LPIs
 
  - Actually check ID_AA64MMFR3_EL1.S1PIE in get-reg-list selftest
 
  - Minor code / comment cleanups for configuring PAuth traps
 
  - Take kvm->arch.config_lock to prevent destruction / initialization
    race for a vCPU's CPUIF which may lead to a UAF
 -----BEGIN PGP SIGNATURE-----
 
 iI0EABYIADUWIQSNXHjWXuzMZutrKNKivnWIJHzdFgUCZrVPUBccb2xpdmVyLnVw
 dG9uQGxpbnV4LmRldgAKCRCivnWIJHzdFoCrAP9ZGQ1M7GdCe4Orm6Ex4R4OMVcz
 MWMrFCVM73rnSoCbMwEA7le7M8c+X5i/4oqFOPm/fEr1i5RZT512RL5lc7MxBQ8=
 =DG57
 -----END PGP SIGNATURE-----

Merge tag 'kvmarm-fixes-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.11, round #1

 - Use kvfree() for the kvmalloc'd nested MMUs array

 - Set of fixes to address warnings in W=1 builds

 - Make KVM depend on assembler support for ARMv8.4

 - Fix for vgic-debug interface for VMs without LPIs

 - Actually check ID_AA64MMFR3_EL1.S1PIE in get-reg-list selftest

 - Minor code / comment cleanups for configuring PAuth traps

 - Take kvm->arch.config_lock to prevent destruction / initialization
   race for a vCPU's CPUIF which may lead to a UAF
2024-08-13 06:06:27 -04:00
Takahiro Itazuri
7fef1eb0b0 docs: KVM: Fix register ID of SPSR_FIQ
Fixes the register ID of SPSR_FIQ.

SPSR_FIQ is a 64-bit register and the 64-bit register size mask is
0x0030000000000000ULL.

Fixes: fd3bc912d3 ("KVM: Documentation: Document arm64 core registers in detail")
Signed-off-by: Takahiro Itazuri <itazur@amazon.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230606154628.95498-1-itazur@amazon.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-08-05 20:16:35 +00:00
Paolo Bonzini
1773014a97 * fix latent bug in how usage of large pages is determined for
confidential VMs
 
 * fix "underline too short" in docs
 
 * eliminate log spam from limited APIC timer periods
 
 * disallow pre-faulting of memory before SEV-SNP VMs are initialized
 
 * delay clearing and encrypting private memory until it is added to
   guest page tables
 
 * this change also enables another small cleanup: the checks in
   SNP_LAUNCH_UPDATE that limit it to non-populated, private pages
   can now be moved in the common kvm_gmem_populate() function
 -----BEGIN PGP SIGNATURE-----
 
 iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmar0uEUHHBib256aW5p
 QHJlZGhhdC5jb20ACgkQv/vSX3jHroMf9Af9EZ0k0HHltM+iUSqKW+hcfnyjRSlh
 MI2m8ZFF4Ra4a/H2CYWbUZSZd6U2TGQoy0cz8vN12uiaaRFSXHAzkoy1zhJGYujq
 ljCUx46Ovo6DDfA1ve9jPdHQNOKWy6Js8yheP+i58Pau1u9fWTewfvWnrwkMgnfD
 lkrSfnWhw7aBy7jTSd8KflRU/IugP2/ApsIhrjZZ9sFGncAwPBbb8NL/u5tI/l6f
 VDp1in5a5gk2PhVRVzvINUxNzhcyuQ0wC07N+B4H+3U0NLg4CwiTBJr/yz0OOWz6
 ThA20/fLTrs5jc2f5APk1EjGT8pqeMJYydI2FdqafSfY0PcTZJtXvzgdSw==
 =CwzF
 -----END PGP SIGNATURE-----

Merge branch 'kvm-fixes' into HEAD

* fix latent bug in how usage of large pages is determined for
  confidential VMs

* fix "underline too short" in docs

* eliminate log spam from limited APIC timer periods

* disallow pre-faulting of memory before SEV-SNP VMs are initialized

* delay clearing and encrypting private memory until it is added to
  guest page tables

* this change also enables another small cleanup: the checks in
  SNP_LAUNCH_UPDATE that limit it to non-populated, private pages
  can now be moved in the common kvm_gmem_populate() function
2024-08-02 12:33:43 -04:00
Paolo Bonzini
5932ca411e KVM: x86: disallow pre-fault for SNP VMs before initialization
KVM_PRE_FAULT_MEMORY for an SNP guest can race with
sev_gmem_post_populate() in bad ways. The following sequence for
instance can potentially trigger an RMP fault:

  thread A, sev_gmem_post_populate: called
  thread B, sev_gmem_prepare: places below 'pfn' in a private state in RMP
  thread A, sev_gmem_post_populate: *vaddr = kmap_local_pfn(pfn + i);
  thread A, sev_gmem_post_populate: copy_from_user(vaddr, src + i * PAGE_SIZE, PAGE_SIZE);
  RMP #PF

Fix this by only allowing KVM_PRE_FAULT_MEMORY to run after a guest's
initial private memory contents have been finalized via
KVM_SEV_SNP_LAUNCH_FINISH.

Beyond fixing this issue, it just sort of makes sense to enforce this,
since the KVM_PRE_FAULT_MEMORY documentation states:

  "KVM maps memory as if the vCPU generated a stage-2 read page fault"

which sort of implies we should be acting on the same guest state that a
vCPU would see post-launch after the initial guest memory is all set up.

Co-developed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-07-26 14:46:14 -04:00
Chang Yu
c2adcf051b KVM: Documentation: Fix title underline too short warning
Fix "WARNING: Title underline too short" by extending title line to the
proper length.

Signed-off-by: Chang Yu <marcus.yu.56@gmail.com>
Message-ID: <ZqB3lofbzMQh5Q-5@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-07-26 13:35:45 -04:00
Linus Torvalds
f9bcc61ad1 This pull request contains the following changes for UML:
- Support for preemption
 - i386 Rust support
 - Huge cleanup by Benjamin Berg
 - UBSAN support
 - Removal of dead code
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCAA0FiEEdgfidid8lnn52cLTZvlZhesYu8EFAmahIpkWHHJpY2hhcmRA
 c2lnbWEtc3Rhci5hdAAKCRBm+VmF6xi7wW4PD/wN03iDGNTPhegGgXTJTSwA8Gwk
 i5JTEmhc84ifE9/bJpru8w4mcLMiWLWFIpF4bGcqfKLp67tTi3jn9Vk7ivaYkn2G
 S875GqjdyqMVMfhJX+1qTxM6q/J5B7XGUpt1Zrot3AY1ANxnlwYscWX8jNvwmf+5
 eCK9+xldkNWh1N67EjwsDgH6kkWyx3fcEe4E3gjXY0eSZtIwO/ZXYHSCSKznJOfu
 iXo1Sx02w8TZp4tf/EwpWR1SMkPL23X8Of+rmiyI5udyLZixTnrFlclu8WUK4ZBO
 ExYvOrzyYZ3E/mPFZf0E88h8xC3ETLsiHO3++JRAM1uDMp1+a6tPK7Bi6NTytemH
 PIT++XRiORAbXu3aSTjpFDAhTHIMZ925eJMvQAtVhtAAwbkjSNh9NbusbMiucPNm
 vvtYrEqYjPJpx+HRxy8kUywe/+jFLYofSDn6YrNRM+3HaM44YgkvbD6AOEMxWq19
 YWkflmkDADez6eti03bAbiVuBB1v+Vnuz15ofrx45IUubb3uGVJYwEqQA5u8bAVr
 H4NeIWDRpXOuYLgSyxRLFFVYhe6eAWbAXeSWBFxcGNDY6OBpMqr7kgV1mBOZtooK
 8aBgZ0YcyiTpmiEevskkNWSBnqUMKIdztKkD7Db9HfCgd9yy7Vvfl+iLJTIqFJ5m
 JxpvTy3it53ghQj40A==
 =ybqq
 -----END PGP SIGNATURE-----

Merge tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux

Pull UML updates from Richard Weinberger:

 - Support for preemption

 - i386 Rust support

 - Huge cleanup by Benjamin Berg

 - UBSAN support

 - Removal of dead code

* tag 'uml-for-linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (41 commits)
  um: vector: always reset vp->opened
  um: vector: remove vp->lock
  um: register power-off handler
  um: line: always fill *error_out in setup_one_line()
  um: remove pcap driver from documentation
  um: Enable preemption in UML
  um: refactor TLB update handling
  um: simplify and consolidate TLB updates
  um: remove force_flush_all from fork_handler
  um: Do not flush MM in flush_thread
  um: Delay flushing syscalls until the thread is restarted
  um: remove copy_context_skas0
  um: remove LDT support
  um: compress memory related stub syscalls while adding them
  um: Rework syscall handling
  um: Add generic stub_syscall6 function
  um: Create signal stack memory assignment in stub_data
  um: Remove stub-data.h include from common-offsets.h
  um: time-travel: fix signal blocking race/hang
  um: time-travel: remove time_exit()
  ...
2024-07-25 12:33:08 -07:00
Linus Torvalds
2c9b351240 ARM:
* Initial infrastructure for shadow stage-2 MMUs, as part of nested
   virtualization enablement
 
 * Support for userspace changes to the guest CTR_EL0 value, enabling
   (in part) migration of VMs between heterogenous hardware
 
 * Fixes + improvements to pKVM's FF-A proxy, adding support for v1.1 of
   the protocol
 
 * FPSIMD/SVE support for nested, including merged trap configuration
   and exception routing
 
 * New command-line parameter to control the WFx trap behavior under KVM
 
 * Introduce kCFI hardening in the EL2 hypervisor
 
 * Fixes + cleanups for handling presence/absence of FEAT_TCRX
 
 * Miscellaneous fixes + documentation updates
 
 LoongArch:
 
 * Add paravirt steal time support.
 
 * Add support for KVM_DIRTY_LOG_INITIALLY_SET.
 
 * Add perf kvm-stat support for loongarch.
 
 RISC-V:
 
 * Redirect AMO load/store access fault traps to guest
 
 * perf kvm stat support
 
 * Use guest files for IMSIC virtualization, when available
 
 ONE_REG support for the Zimop, Zcmop, Zca, Zcf, Zcd, Zcb and Zawrs ISA
 extensions is coming through the RISC-V tree.
 
 s390:
 
 * Assortment of tiny fixes which are not time critical
 
 x86:
 
 * Fixes for Xen emulation.
 
 * Add a global struct to consolidate tracking of host values, e.g. EFER
 
 * Add KVM_CAP_X86_APIC_BUS_CYCLES_NS to allow configuring the effective APIC
   bus frequency, because TDX.
 
 * Print the name of the APICv/AVIC inhibits in the relevant tracepoint.
 
 * Clean up KVM's handling of vendor specific emulation to consistently act on
   "compatible with Intel/AMD", versus checking for a specific vendor.
 
 * Drop MTRR virtualization, and instead always honor guest PAT on CPUs
   that support self-snoop.
 
 * Update to the newfangled Intel CPU FMS infrastructure.
 
 * Don't advertise IA32_PERF_GLOBAL_OVF_CTRL as an MSR-to-be-saved, as it reads
   '0' and writes from userspace are ignored.
 
 * Misc cleanups
 
 x86 - MMU:
 
 * Small cleanups, renames and refactoring extracted from the upcoming
   Intel TDX support.
 
 * Don't allocate kvm_mmu_page.shadowed_translation for shadow pages that can't
   hold leafs SPTEs.
 
 * Unconditionally drop mmu_lock when allocating TDP MMU page tables for eager
   page splitting, to avoid stalling vCPUs when splitting huge pages.
 
 * Bug the VM instead of simply warning if KVM tries to split a SPTE that is
   non-present or not-huge.  KVM is guaranteed to end up in a broken state
   because the callers fully expect a valid SPTE, it's all but dangerous
   to let more MMU changes happen afterwards.
 
 x86 - AMD:
 
 * Make per-CPU save_area allocations NUMA-aware.
 
 * Force sev_es_host_save_area() to be inlined to avoid calling into an
   instrumentable function from noinstr code.
 
 * Base support for running SEV-SNP guests.  API-wise, this includes
   a new KVM_X86_SNP_VM type, encrypting/measure the initial image into
   guest memory, and finalizing it before launching it.  Internally,
   there are some gmem/mmu hooks needed to prepare gmem-allocated pages
   before mapping them into guest private memory ranges.
 
   This includes basic support for attestation guest requests, enough to
   say that KVM supports the GHCB 2.0 specification.
 
   There is no support yet for loading into the firmware those signing
   keys to be used for attestation requests, and therefore no need yet
   for the host to provide certificate data for those keys.  To support
   fetching certificate data from userspace, a new KVM exit type will be
   needed to handle fetching the certificate from userspace. An attempt to
   define a new KVM_EXIT_COCO/KVM_EXIT_COCO_REQ_CERTS exit type to handle
   this was introduced in v1 of this patchset, but is still being discussed
   by community, so for now this patchset only implements a stub version
   of SNP Extended Guest Requests that does not provide certificate data.
 
 x86 - Intel:
 
 * Remove an unnecessary EPT TLB flush when enabling hardware.
 
 * Fix a series of bugs that cause KVM to fail to detect nested pending posted
   interrupts as valid wake eents for a vCPU executing HLT in L2 (with
   HLT-exiting disable by L1).
 
 * KVM: x86: Suppress MMIO that is triggered during task switch emulation
 
   Explicitly suppress userspace emulated MMIO exits that are triggered when
   emulating a task switch as KVM doesn't support userspace MMIO during
   complex (multi-step) emulation.  Silently ignoring the exit request can
   result in the WARN_ON_ONCE(vcpu->mmio_needed) firing if KVM exits to
   userspace for some other reason prior to purging mmio_needed.
 
   See commit 0dc902267c ("KVM: x86: Suppress pending MMIO write exits if
   emulator detects exception") for more details on KVM's limitations with
   respect to emulated MMIO during complex emulator flows.
 
 Generic:
 
 * Rename the AS_UNMOVABLE flag that was introduced for KVM to AS_INACCESSIBLE,
   because the special casing needed by these pages is not due to just
   unmovability (and in fact they are only unmovable because the CPU cannot
   access them).
 
 * New ioctl to populate the KVM page tables in advance, which is useful to
   mitigate KVM page faults during guest boot or after live migration.
   The code will also be used by TDX, but (probably) not through the ioctl.
 
 * 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.
 
 Selftests:
 
 * Remove dead code in the memslot modification stress test.
 
 * Treat "branch instructions retired" as supported on all AMD Family 17h+ CPUs.
 
 * Print the guest pseudo-RNG seed only when it changes, to avoid spamming the
   log for tests that create lots of VMs.
 
 * Make the PMU counters test less flaky when counting LLC cache misses by
   doing CLFLUSH{OPT} in every loop iteration.
 -----BEGIN PGP SIGNATURE-----
 
 iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmaZQB0UHHBib256aW5p
 QHJlZGhhdC5jb20ACgkQv/vSX3jHroNkZwf/bv2jiENaLFNGPe/VqTKMQ6PHQLMG
 +sNHx6fJPP35gTM8Jqf0/7/ummZXcSuC1mWrzYbecZm7Oeg3vwNXHZ4LquwwX6Dv
 8dKcUzLbWDAC4WA3SKhi8C8RV2v6E7ohy69NtAJmFWTc7H95dtIQm6cduV2osTC3
 OEuHe1i8d9umk6couL9Qhm8hk3i9v2KgCsrfyNrQgLtS3hu7q6yOTR8nT0iH6sJR
 KE5A8prBQgLmF34CuvYDw4Hu6E4j+0QmIqodovg2884W1gZQ9LmcVqYPaRZGsG8S
 iDdbkualLKwiR1TpRr3HJGKWSFdc7RblbsnHRvHIZgFsMQiimh4HrBSCyQ==
 =zepX
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM:

   - Initial infrastructure for shadow stage-2 MMUs, as part of nested
     virtualization enablement

   - Support for userspace changes to the guest CTR_EL0 value, enabling
     (in part) migration of VMs between heterogenous hardware

   - Fixes + improvements to pKVM's FF-A proxy, adding support for v1.1
     of the protocol

   - FPSIMD/SVE support for nested, including merged trap configuration
     and exception routing

   - New command-line parameter to control the WFx trap behavior under
     KVM

   - Introduce kCFI hardening in the EL2 hypervisor

   - Fixes + cleanups for handling presence/absence of FEAT_TCRX

   - Miscellaneous fixes + documentation updates

  LoongArch:

   - Add paravirt steal time support

   - Add support for KVM_DIRTY_LOG_INITIALLY_SET

   - Add perf kvm-stat support for loongarch

  RISC-V:

   - Redirect AMO load/store access fault traps to guest

   - perf kvm stat support

   - Use guest files for IMSIC virtualization, when available

  s390:

   - Assortment of tiny fixes which are not time critical

  x86:

   - Fixes for Xen emulation

   - Add a global struct to consolidate tracking of host values, e.g.
     EFER

   - Add KVM_CAP_X86_APIC_BUS_CYCLES_NS to allow configuring the
     effective APIC bus frequency, because TDX

   - Print the name of the APICv/AVIC inhibits in the relevant
     tracepoint

   - Clean up KVM's handling of vendor specific emulation to
     consistently act on "compatible with Intel/AMD", versus checking
     for a specific vendor

   - Drop MTRR virtualization, and instead always honor guest PAT on
     CPUs that support self-snoop

   - Update to the newfangled Intel CPU FMS infrastructure

   - Don't advertise IA32_PERF_GLOBAL_OVF_CTRL as an MSR-to-be-saved, as
     it reads '0' and writes from userspace are ignored

   - Misc cleanups

  x86 - MMU:

   - Small cleanups, renames and refactoring extracted from the upcoming
     Intel TDX support

   - Don't allocate kvm_mmu_page.shadowed_translation for shadow pages
     that can't hold leafs SPTEs

   - Unconditionally drop mmu_lock when allocating TDP MMU page tables
     for eager page splitting, to avoid stalling vCPUs when splitting
     huge pages

   - Bug the VM instead of simply warning if KVM tries to split a SPTE
     that is non-present or not-huge. KVM is guaranteed to end up in a
     broken state because the callers fully expect a valid SPTE, it's
     all but dangerous to let more MMU changes happen afterwards

  x86 - AMD:

   - Make per-CPU save_area allocations NUMA-aware

   - Force sev_es_host_save_area() to be inlined to avoid calling into
     an instrumentable function from noinstr code

   - Base support for running SEV-SNP guests. API-wise, this includes a
     new KVM_X86_SNP_VM type, encrypting/measure the initial image into
     guest memory, and finalizing it before launching it. Internally,
     there are some gmem/mmu hooks needed to prepare gmem-allocated
     pages before mapping them into guest private memory ranges

     This includes basic support for attestation guest requests, enough
     to say that KVM supports the GHCB 2.0 specification

     There is no support yet for loading into the firmware those signing
     keys to be used for attestation requests, and therefore no need yet
     for the host to provide certificate data for those keys.

     To support fetching certificate data from userspace, a new KVM exit
     type will be needed to handle fetching the certificate from
     userspace.

     An attempt to define a new KVM_EXIT_COCO / KVM_EXIT_COCO_REQ_CERTS
     exit type to handle this was introduced in v1 of this patchset, but
     is still being discussed by community, so for now this patchset
     only implements a stub version of SNP Extended Guest Requests that
     does not provide certificate data

  x86 - Intel:

   - Remove an unnecessary EPT TLB flush when enabling hardware

   - Fix a series of bugs that cause KVM to fail to detect nested
     pending posted interrupts as valid wake eents for a vCPU executing
     HLT in L2 (with HLT-exiting disable by L1)

   - KVM: x86: Suppress MMIO that is triggered during task switch
     emulation

     Explicitly suppress userspace emulated MMIO exits that are
     triggered when emulating a task switch as KVM doesn't support
     userspace MMIO during complex (multi-step) emulation

     Silently ignoring the exit request can result in the
     WARN_ON_ONCE(vcpu->mmio_needed) firing if KVM exits to userspace
     for some other reason prior to purging mmio_needed

     See commit 0dc902267c ("KVM: x86: Suppress pending MMIO write
     exits if emulator detects exception") for more details on KVM's
     limitations with respect to emulated MMIO during complex emulator
     flows

  Generic:

   - Rename the AS_UNMOVABLE flag that was introduced for KVM to
     AS_INACCESSIBLE, because the special casing needed by these pages
     is not due to just unmovability (and in fact they are only
     unmovable because the CPU cannot access them)

   - New ioctl to populate the KVM page tables in advance, which is
     useful to mitigate KVM page faults during guest boot or after live
     migration. The code will also be used by TDX, but (probably) not
     through the ioctl

   - 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

  Selftests:

   - Remove dead code in the memslot modification stress test

   - Treat "branch instructions retired" as supported on all AMD Family
     17h+ CPUs

   - Print the guest pseudo-RNG seed only when it changes, to avoid
     spamming the log for tests that create lots of VMs

   - Make the PMU counters test less flaky when counting LLC cache
     misses by doing CLFLUSH{OPT} in every loop iteration"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (227 commits)
  crypto: ccp: Add the SNP_VLEK_LOAD command
  KVM: x86/pmu: Add kvm_pmu_call() to simplify static calls of kvm_pmu_ops
  KVM: x86: Introduce kvm_x86_call() to simplify static calls of kvm_x86_ops
  KVM: x86: Replace static_call_cond() with static_call()
  KVM: SEV: Provide support for SNP_EXTENDED_GUEST_REQUEST NAE event
  x86/sev: Move sev_guest.h into common SEV header
  KVM: SEV: Provide support for SNP_GUEST_REQUEST NAE event
  KVM: x86: Suppress MMIO that is triggered during task switch emulation
  KVM: x86/mmu: Clean up make_huge_page_split_spte() definition and intro
  KVM: x86/mmu: Bug the VM if KVM tries to split a !hugepage SPTE
  KVM: selftests: x86: Add test for KVM_PRE_FAULT_MEMORY
  KVM: x86: Implement kvm_arch_vcpu_pre_fault_memory()
  KVM: x86/mmu: Make kvm_mmu_do_page_fault() return mapped level
  KVM: x86/mmu: Account pf_{fixed,emulate,spurious} in callers of "do page fault"
  KVM: x86/mmu: Bump pf_taken stat only in the "real" page fault handler
  KVM: Add KVM_PRE_FAULT_MEMORY vcpu ioctl to pre-populate guest memory
  KVM: Document KVM_PRE_FAULT_MEMORY ioctl
  mm, virt: merge AS_UNMOVABLE and AS_INACCESSIBLE
  perf kvm: Add kvm-stat for loongarch64
  LoongArch: KVM: Add PV steal time support in guest side
  ...
2024-07-20 12:41:03 -07:00
Linus Torvalds
3c3ff7be97 powerpc updates for 6.11
- Remove support for 40x CPUs & platforms.
 
  - Add support to the 64-bit BPF JIT for cpu v4 instructions.
 
  - Fix PCI hotplug driver crash on powernv.
 
  - Fix doorbell emulation for KVM on PAPR guests (nestedv2).
 
  - Fix KVM nested guest handling of some less used SPRs.
 
  - Online NUMA nodes with no CPU/memory if they have a PCI device attached.
 
  - Reduce memory overhead of enabling kfence on 64-bit Radix MMU kernels.
 
  - Reimplement the iommu table_group_ops for pseries for VFIO SPAPR TCE.
 
 Thanks to: Anjali K, Artem Savkov, Athira Rajeev, Breno Leitao, Brian King,
 Celeste Liu, Christophe Leroy, Esben Haabendal, Gaurav Batra, Gautam Menghani,
 Haren Myneni, Hari Bathini, Jeff Johnson, Krishna Kumar, Krzysztof Kozlowski,
 Nathan Lynch, Nicholas Piggin, Nick Bowler, Nilay Shroff, Rob Herring (Arm),
 Shawn Anastasio, Shivaprasad G Bhat, Sourabh Jain, Srikar Dronamraju, Timothy
 Pearson, Uwe Kleine-König, Vaibhav Jain.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCAAxFiEEJFGtCPCthwEv2Y/bUevqPMjhpYAFAmaaUNITHG1wZUBlbGxl
 cm1hbi5pZC5hdQAKCRBR6+o8yOGlgDA+D/4o7OZ+SY0plTlMKSy3hW/SRXVj/byA
 CCKdizNY+3Rf/+K7KhuLOUPXhZOemLPE0xfKS3ND4mIEKCswzzXqmi6kjPH0qd8q
 qUhkHbt/LNpNJzZOYYw+usaklMTMdZtAl/jD9WEvGwgu2EYHgrujRIq04kEI1b0e
 OPiRnXOZcfevRBepQmYZKHvFlCRRa5vvsQcvLfY64yFqD0AsKTHgIi/48Dn33pb2
 hqHYyV1tZA3uT86Z1TgF1OG83VOSDsgc19Sb2xn14O9aJJ7lD2TOgVa4P4FfBlXA
 TXYYGQwK31ymGVWGcGfebVdC1ECeTem9n28vlk5I0NO9xNgPok/Ov4DAiZ+u1G0E
 3CXRDx9Uz2yPcGBJI2dpxfp2iw83Ad2DtBzAdukMD36xnC7xfrQz+W9SQfbcPJ8e
 I5SMAstWuLNgrX7YkjAOnXh1N41kht/mdV6KHdcMxPc7jOtAD65gUOZcgwYLeXlT
 Av17Ax0PMbiQ1BpFe2KNr/0T9Ba5k5rN7oDSKncDAq4uX8LcZKHj4bSHT9KroT1C
 q+GERspoCYp2VDMO742Jm7KTmQDHsS5y4Q+iSdOR8cQBXF613FaryDxSoJZhg2pf
 C2zIVED13RGcjIFcWlv73iA6QpBsphM+WWFz7mjULyJhxFQwm6BYt+Wy6jFu84oH
 sOgvPH8YyaK2uA==
 =eHVd
 -----END PGP SIGNATURE-----

Merge tag 'powerpc-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Remove support for 40x CPUs & platforms

 - Add support to the 64-bit BPF JIT for cpu v4 instructions

 - Fix PCI hotplug driver crash on powernv

 - Fix doorbell emulation for KVM on PAPR guests (nestedv2)

 - Fix KVM nested guest handling of some less used SPRs

 - Online NUMA nodes with no CPU/memory if they have a PCI device
   attached

 - Reduce memory overhead of enabling kfence on 64-bit Radix MMU kernels

 - Reimplement the iommu table_group_ops for pseries for VFIO SPAPR TCE

Thanks to: Anjali K, Artem Savkov, Athira Rajeev, Breno Leitao, Brian
King, Celeste Liu, Christophe Leroy, Esben Haabendal, Gaurav Batra,
Gautam Menghani, Haren Myneni, Hari Bathini, Jeff Johnson, Krishna
Kumar, Krzysztof Kozlowski, Nathan Lynch, Nicholas Piggin, Nick Bowler,
Nilay Shroff, Rob Herring (Arm), Shawn Anastasio, Shivaprasad G Bhat,
Sourabh Jain, Srikar Dronamraju, Timothy Pearson, Uwe Kleine-König, and
Vaibhav Jain.

* tag 'powerpc-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (57 commits)
  Documentation/powerpc: Mention 40x is removed
  powerpc: Remove 40x leftovers
  macintosh/therm_windtunnel: fix module unload.
  powerpc: Check only single values are passed to CPU/MMU feature checks
  powerpc/xmon: Fix disassembly CPU feature checks
  powerpc: Drop clang workaround for builtin constant checks
  powerpc64/bpf: jit support for signed division and modulo
  powerpc64/bpf: jit support for sign extended mov
  powerpc64/bpf: jit support for sign extended load
  powerpc64/bpf: jit support for unconditional byte swap
  powerpc64/bpf: jit support for 32bit offset jmp instruction
  powerpc/pci: Hotplug driver bridge support
  pci/hotplug/pnv_php: Fix hotplug driver crash on Powernv
  powerpc/configs: Update defconfig with now user-visible CONFIG_FSL_IFC
  powerpc: add missing MODULE_DESCRIPTION() macros
  macintosh/mac_hid: add MODULE_DESCRIPTION()
  KVM: PPC: add missing MODULE_DESCRIPTION() macros
  powerpc/kexec: Use of_property_read_reg()
  powerpc/64s/radix/kfence: map __kfence_pool at page granularity
  powerpc/pseries/iommu: Define spapr_tce_table_group_ops only with CONFIG_IOMMU_API
  ...
2024-07-19 21:00:33 -07:00
Michael Roth
332d2c1d71 crypto: ccp: Add the SNP_VLEK_LOAD command
When requesting an attestation report a guest is able to specify whether
it wants SNP firmware to sign the report using either a Versioned Chip
Endorsement Key (VCEK), which is derived from chip-unique secrets, or a
Versioned Loaded Endorsement Key (VLEK) which is obtained from an AMD
Key Derivation Service (KDS) and derived from seeds allocated to
enrolled cloud service providers (CSPs).

For VLEK keys, an SNP_VLEK_LOAD SNP firmware command is used to load
them into the system after obtaining them from the KDS. Add a
corresponding userspace interface so to allow the loading of VLEK keys
into the system.

See SEV-SNP Firmware ABI 1.54, SNP_VLEK_LOAD for more details.

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Message-ID: <20240501085210.2213060-21-michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-07-17 12:46:26 -04:00
Linus Torvalds
408323581b - Add support for running the kernel in a SEV-SNP guest, over a Secure
VM Service Module (SVSM).
 
    When running over a SVSM, different services can run at different
    protection levels, apart from the guest OS but still within the
    secure SNP environment.  They can provide services to the guest, like
    a vTPM, for example.
 
    This series adds the required facilities to interface with such a SVSM
    module.
 
  - The usual fixlets, refactoring and cleanups
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmaWQuoACgkQEsHwGGHe
 VUrmEw/+KqM5DK5cfpue3gn0RfH6OYUoFxOdYhGkG53qUMc3c3ka5zPVqLoHPkzp
 WPXha0Z5pVdrcD9mKtVUW9RIuLjInCM/mnoNc3tIUL+09xxemAjyG1+O+4kodiU7
 sZ5+HuKUM2ihoC4Rrm+ApRrZfH4+WcgQNvFky77iObWVBo4yIscS7Pet/MYFvuuz
 zNaGp2SGGExDeoX/pMQNI3S9FKYD26HR17AUI3DHpS0teUl2npVi4xDjFVYZh0dQ
 yAhTKbSX3Q6ekDDkvAQUbxvWTJw9qoIsvLO9dvZdx6SSWmzF9IbuECpQKGQwYcp+
 pVtcHb+3MwfB+nh5/fHyssRTOZp1UuI5GcmLHIQhmhQwCqPgzDH6te4Ud1ovkxOu
 3GoBre7KydnQIyv12I+56/ZxyPbjHWmn8Fg106nAwGTdGbBJhfcVYfPmPvwpI4ib
 nXpjypvM8FkLzLAzDK6GE9QiXqJJlxOn7t66JiH/FkXR4gnY3eI8JLMfnm5blAb+
 97LC7oyeqtstWth9/4tpCILgPR2tirrMQGjUXttgt+2VMzqnEamnFozsKvR95xok
 4j6ulKglZjdpn0ixHb2vAzAcOJvD7NP147jtCmXH7M6/f9H1Lih3MKdxX98MVhWB
 wSp16udXHzu5lF45J0BJG8uejSgBI2y51jc92HLX7kRULOGyaEo=
 =u15r
 -----END PGP SIGNATURE-----

Merge tag 'x86_sev_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 SEV updates from Borislav Petkov:

 - Add support for running the kernel in a SEV-SNP guest, over a Secure
   VM Service Module (SVSM).

   When running over a SVSM, different services can run at different
   protection levels, apart from the guest OS but still within the
   secure SNP environment. They can provide services to the guest, like
   a vTPM, for example.

   This series adds the required facilities to interface with such a
   SVSM module.

 - The usual fixlets, refactoring and cleanups

[ And as always: "SEV" is AMD's "Secure Encrypted Virtualization".

  I can't be the only one who gets all the newer x86 TLA's confused,
  can I?
              - Linus ]

* tag 'x86_sev_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation/ABI/configfs-tsm: Fix an unexpected indentation silly
  x86/sev: Do RMP memory coverage check after max_pfn has been set
  x86/sev: Move SEV compilation units
  virt: sev-guest: Mark driver struct with __refdata to prevent section mismatch
  x86/sev: Allow non-VMPL0 execution when an SVSM is present
  x86/sev: Extend the config-fs attestation support for an SVSM
  x86/sev: Take advantage of configfs visibility support in TSM
  fs/configfs: Add a callback to determine attribute visibility
  sev-guest: configfs-tsm: Allow the privlevel_floor attribute to be updated
  virt: sev-guest: Choose the VMPCK key based on executing VMPL
  x86/sev: Provide guest VMPL level to userspace
  x86/sev: Provide SVSM discovery support
  x86/sev: Use the SVSM to create a vCPU when not in VMPL0
  x86/sev: Perform PVALIDATE using the SVSM when not at VMPL0
  x86/sev: Use kernel provided SVSM Calling Areas
  x86/sev: Check for the presence of an SVSM in the SNP secrets page
  x86/irqflags: Provide native versions of the local_irq_save()/restore()
2024-07-16 11:12:25 -07:00
Paolo Bonzini
5c5ddf7107 KVM x86 MTRR virtualization removal
Remove support for virtualizing MTRRs on Intel CPUs, along with a nasty CR0.CD
 hack, and instead always honor guest PAT on CPUs that support self-snoop.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEKTobbabEP7vbhhN9OlYIJqCjN/0FAmaRuwAACgkQOlYIJqCj
 N/32Gg/+Nnnz6TCRno2vursPJme7gvtLdqSxjazAj3u2ZO8IApGYWMyfVpS+ymC9
 Wdpj6gRe2ukSxgTsUI2CYoy5V2NxDaA9YgdTPZUVQvqwujVrqZCJ7L393iPYYnC9
 No3LXZ+SOYRmomiCzknjC6GOlT2hAZHzQsyaXDlEYok7NAA2L6XybbLonEdA4RYi
 V1mS62W5PaA4tUesuxkJjPujXo1nXRWD/aXOruJWjPESdSFSALlx7reFAf2Nwn7K
 Uw8yZqhq6vWAZSph0Nz8OrZOS/kULKA3q2zl1B/qJJ0ToAt2VdXS6abXky52RExf
 KvP+jBAWMO5kHbIqaMRtCHjbIkbhH8RdUIYNJQEUQ5DdydM5+/RDa+KprmLPcmUn
 qvJq+3uyH0MEENtneGegs8uxR+sn6fT32cGMIw790yIywddh562+IJ4Z+C3BuYJi
 yszD71odqKT8+knUd2CaZjE9UZyoQNDfj2OCCTzzZOC/6TuJWCh9CYQ1csssHbQR
 KcvZCKE6ht8tWwi+2HWj0laOdg1reX2kV869k3xH4uCwEaFIj2Wk+/Bw/lg2Tn5h
 5uTnQ01dx5XhAV1klr6IY3VXJ/A8G8895wRfkZEelsA9Wj8qZvNgXhsoXReIUIrn
 aR0ppsFcbqHzC50qE2JT4juTD1EPx95LL9zKT8pI9mGKwxCAxUM=
 =yb10
 -----END PGP SIGNATURE-----

Merge tag 'kvm-x86-mtrrs-6.11' of https://github.com/kvm-x86/linux into HEAD

KVM x86 MTRR virtualization removal

Remove support for virtualizing MTRRs on Intel CPUs, along with a nasty CR0.CD
hack, and instead always honor guest PAT on CPUs that support self-snoop.
2024-07-16 09:54:57 -04:00
Paolo Bonzini
5dcc1e7614 KVM x86 misc changes for 6.11
- Add a global struct to consolidate tracking of host values, e.g. EFER, and
    move "shadow_phys_bits" into the structure as "maxphyaddr".
 
  - Add KVM_CAP_X86_APIC_BUS_CYCLES_NS to allow configuring the effective APIC
    bus frequency, because TDX.
 
  - Print the name of the APICv/AVIC inhibits in the relevant tracepoint.
 
  - Clean up KVM's handling of vendor specific emulation to consistently act on
    "compatible with Intel/AMD", versus checking for a specific vendor.
 
  - Misc cleanups
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEKTobbabEP7vbhhN9OlYIJqCjN/0FAmaRub0ACgkQOlYIJqCj
 N/2LMxAArGzhcWZ6Qdo2aMRaMIPtSBJHmbEgEuHvHMumgsTZQzDcn9cxDi/hNSrc
 l8ODOwAM2qNcq95YfwjU7F0ae3E+HRzGvKcBnmZWuQeCDp2HhVEoCphFu1sHst+t
 XEJTL02b6OgyJUEU3h40mYk12eiq2S4FCnFYXPCqijwwuL6Y5KQvvTqek3c2/SDn
 c+VneutYGax/S0GiiCkYh4wrwWh9g7qm0IX70ycBwJbW5qBFKgyglvHxvL8JLJC9
 Nkkw/p2657wcOdraH+fOBuRy2dMwE5fv++1tOjWwB5WAAhSOJPZh0BGYvgA2yfN7
 OE+k7APKUQd9Xxtud8H3LrTPoyMA4hz2sdDFyqrrWK9yjpBY7zXNyN50Fxi7VVsm
 T8nTIiKAGyRbjotY+m7krXQPXjfZYhVqrJ/jtxESOZLZ93q2gSWU2p/ZXpUPVHnH
 +YOBAI1owP3wepaYlrthtI4LQx9lF422dnmeSflztfKFGabRbQZxg3uHMCCxIaGc
 lJ6CD546+D45f/uBXRDMqk//qFTqXhKUbDk9sutmU/C2oWufMwW0R8kOyItGPyvk
 9PP1vd8vSsIHj+tpwg+i04jBqYDaAcPBOcTZaHm9SYYP+1e11Uu5Vjep37JL1bkA
 xJWxnDZOCGcfKQi2jkh51HJ/dOAHXY1GQKMfyAoPQOSonYHvGVY=
 =Cf2R
 -----END PGP SIGNATURE-----

Merge tag 'kvm-x86-misc-6.11' of https://github.com/kvm-x86/linux into HEAD

KVM x86 misc changes for 6.11

 - Add a global struct to consolidate tracking of host values, e.g. EFER, and
   move "shadow_phys_bits" into the structure as "maxphyaddr".

 - Add KVM_CAP_X86_APIC_BUS_CYCLES_NS to allow configuring the effective APIC
   bus frequency, because TDX.

 - Print the name of the APICv/AVIC inhibits in the relevant tracepoint.

 - Clean up KVM's handling of vendor specific emulation to consistently act on
   "compatible with Intel/AMD", versus checking for a specific vendor.

 - Misc cleanups
2024-07-16 09:53:05 -04:00
Paolo Bonzini
86014c1e20 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
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEKTobbabEP7vbhhN9OlYIJqCjN/0FAmaRuOYACgkQOlYIJqCj
 N/1UnQ/8CI5Qfr+/0gzYgtWmtEMczGG+rMNpzD3XVqPjJjXcMcBiQnplnzUVLhha
 vlPdYVK7vgmEt003XGzV55mik46LHL+DX/v4hI3HEdblfyCeNLW3fKEWVRB44qJe
 o+YUQwSK42SORUp9oXuQINxhA//U9EnI7CQxlJ8w8wenv5IJKfIGr01DefmfGPAV
 PKm9t6WLcNqvhZMEyy/zmzM3KVPCJL0NcwI97x6sHxFpQYIDtL0E/VexA4AFqMoT
 QK7cSDC/2US41Zvem/r/GzM/ucdF6vb9suzZYBohwhxtVhwJe2CDeYQZvtNKJ1U7
 GOHPaKL6nBWdZCm/yyWbbX2nstY1lHqxhN3JD0X8wqU5rNcwm2b8Vfyav0Ehc7H+
 jVbDTshOx4YJmIgajoKjgM050rdBK59TdfVL+l+AAV5q/TlHocalYtvkEBdGmIDg
 2td9UHSime6sp20vQfczUEz4bgrQsh4l2Fa/qU2jFwLievnBw0AvEaMximkSGMJe
 b8XfjmdTjlOesWAejANKtQolfrq14+1wYw0zZZ8PA+uNVpKdoovmcqSOcaDC9bT8
 GO/NFUvoG+lkcvJcIlo1SSl81SmGLosijwxWfGvFAqsgpR3/3l3dYp0QtztoCNJO
 d3+HnjgYn5o5FwufuTD3eUOXH4AFjG108DH0o25XrIkb2Kymy0o=
 =BalU
 -----END PGP SIGNATURE-----

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
2024-07-16 09:51:36 -04:00
Paolo Bonzini
1c5a0b55ab KVM/arm64 changes for 6.11
- Initial infrastructure for shadow stage-2 MMUs, as part of nested
    virtualization enablement
 
  - Support for userspace changes to the guest CTR_EL0 value, enabling
    (in part) migration of VMs between heterogenous hardware
 
  - Fixes + improvements to pKVM's FF-A proxy, adding support for v1.1 of
    the protocol
 
  - FPSIMD/SVE support for nested, including merged trap configuration
    and exception routing
 
  - New command-line parameter to control the WFx trap behavior under KVM
 
  - Introduce kCFI hardening in the EL2 hypervisor
 
  - Fixes + cleanups for handling presence/absence of FEAT_TCRX
 
  - Miscellaneous fixes + documentation updates
 -----BEGIN PGP SIGNATURE-----
 
 iI0EABYIADUWIQSNXHjWXuzMZutrKNKivnWIJHzdFgUCZpTCAxccb2xpdmVyLnVw
 dG9uQGxpbnV4LmRldgAKCRCivnWIJHzdFjChAQCWs9ucJag4USgvXpg5mo9sxzly
 kBZZ1o49N/VLxs4cagEAtq3KVNQNQyGXelYH6gr20aI85j6VnZW5W5z+sy5TAgk=
 =sSOt
 -----END PGP SIGNATURE-----

Merge tag 'kvmarm-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 changes for 6.11

 - Initial infrastructure for shadow stage-2 MMUs, as part of nested
   virtualization enablement

 - Support for userspace changes to the guest CTR_EL0 value, enabling
   (in part) migration of VMs between heterogenous hardware

 - Fixes + improvements to pKVM's FF-A proxy, adding support for v1.1 of
   the protocol

 - FPSIMD/SVE support for nested, including merged trap configuration
   and exception routing

 - New command-line parameter to control the WFx trap behavior under KVM

 - Introduce kCFI hardening in the EL2 hypervisor

 - Fixes + cleanups for handling presence/absence of FEAT_TCRX

 - Miscellaneous fixes + documentation updates
2024-07-16 09:50:44 -04:00
Paolo Bonzini
c8b8b8190a LoongArch KVM changes for v6.11
1. Add ParaVirt steal time support.
 2. Add some VM migration enhancement.
 3. Add perf kvm-stat support for loongarch.
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCAA0FiEEzOlt8mkP+tbeiYy5AoYrw/LiJnoFAmaOS6UWHGNoZW5odWFj
 YWlAa2VybmVsLm9yZwAKCRAChivD8uImehejD/9pACGe3h3krXLcFVWXOFIu5Hpc
 5kQLP0lSPJ/o5Xs8t/oPLrnDX70z90wXI1LOmltc7h32MSwFa2l8COQh+sN5eJBQ
 PNyt7u7bMipp0yJS4Gl3LQQ5vklcGOSpQc/gbeXnVx8J/tz+Mo9YGGLIXVRXRM6W
 Ri8D2VVFiwzQQYeTpPo1u1Ob8C6mA4KOppwvhscMTM3vj4NMbsinBzRnR0lG0Tdw
 meFhxDPly1Ksxsbnj9UGO6UnEY0A2SLONs6MiO4y4DtoqoDlw/lbqFJuYo4vvbx1
 pxtjyirD/PX/wjslQFWUOuU0hMfAodera+JupZ5BZWfcG8FltA4DQfDsm/U9RjK/
 7gGNnr8Xk2/tp6+4AVV+HU2iTgRvq+mXCL72zSy2Y4r7ElBAANDfk4n+Zn/PWisn
 U9wwV8Ue7tVB15BRpRsg77NzBidiCFEe/6flWYiX2y24ke71gwDJBGUy8hMdKt6t
 4Cq8atsU0MvDAzfYMsK9JjskJp4UFq6wb1tXbbuADM4TDhnzlK6s6h3vM+pFlh/f
 my7fDH8/2qsCWhBDM4pmsJskVp+I1GOk/80RjTQISwx7iHktJWvxNYTaisK2fvD5
 Qs1IUWfNFbDX0Lr0QpN6j6X4rZkghR4R6XoFkd4nkicwi+UHVn3oK9GSqv24QJn9
 7+Ev3dfRTUYLd6mC4Q==
 =DpIK
 -----END PGP SIGNATURE-----

Merge tag 'loongarch-kvm-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD

LoongArch KVM changes for v6.11

1. Add ParaVirt steal time support.
2. Add some VM migration enhancement.
3. Add perf kvm-stat support for loongarch.
2024-07-12 11:24:12 -04:00
Paolo Bonzini
f0a23883fa Assortment of tiny fixes which are not time critical:
- Rejecting memory region operations for ucontrol mode VMs
  - Rewind the PSW on host intercepts for VSIE
  - Remove unneeded include
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEwGNS88vfc9+v45Yq41TmuOI4ufgFAmaOeL8ACgkQ41TmuOI4
 ufgL/RAAs5AKJIeV/iuxUDTyJAA0Jhu61xhFbO4u50K5Bxc+pr+DCBWvOGPMtI1D
 dYUqUGN1Ii47tHJ4oztQzAQnX+PCCyxemOjuUinzzyhJKuwusJHYW57wXPBE8a4t
 HI/6huTkL7zHJ1nml/S9YkTpdzVA0a6AOEWzV/+tinmjlDRrLEkKGGto2sNN+rym
 +K+QLt8+RGHDWORCE1fry51sgv4liKna+V9kEgJBlO17jR1tWNIpdaozyZ7agLLT
 Fi45nd4eqZqAqDixQ0avggPk/spfUxwqJackqqWPDjGGyQ9kgjOs4AuuMFD5naoF
 UbueRjjYtpPRPw1XVfvblXLiDhNWveS3vF4D0Dg8+2TVwYXmg1Yhy/pAACNja+wJ
 uZSTjqSU/soYgIWfVWo6mTnCNdxvgBZXpPA6t6feky4RZzsnSrDf8EIHvYUHcqRo
 nNRfseWKhi0Kq0t1Cy2WBBdjJnupQLnTz8ft+RRGf9XU6mYaiJ+XO4dL3P9pNFGc
 qHL6QkGG2EsRHXD4n3b+rB0qOu8BzmwcgqFZGlv9hAgnXFYDmgMYEm0CBhMqigDy
 5d2CTwvGTqU2nxXxxPsYpNDAEam4WoC6aLJgephPfBqbHv4BCtUmwByNk9DBkFsv
 czQp6XOlyimRAIniD0Mwl/aigEc9rB232WlU7zZzzg5qYlxHj+g=
 =D4sp
 -----END PGP SIGNATURE-----

Merge tag 'kvm-s390-next-6.11-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

Assortment of tiny fixes which are not time critical:
- Rejecting memory region operations for ucontrol mode VMs
- Rewind the PSW on host intercepts for VSIE
- Remove unneeded include
2024-07-12 11:23:19 -04:00
Isaku Yamahata
9aed7a6c0b KVM: Document KVM_PRE_FAULT_MEMORY ioctl
Adds documentation of KVM_PRE_FAULT_MEMORY ioctl. [1]

It populates guest memory.  It doesn't do extra operations on the
underlying technology-specific initialization [2].  For example,
CoCo-related operations won't be performed.  Concretely for TDX, this API
won't invoke TDH.MEM.PAGE.ADD() or TDH.MR.EXTEND().  Vendor-specific APIs
are required for such operations.

The key point is to adapt of vcpu ioctl instead of VM ioctl.  First,
populating guest memory requires vcpu.  If it is VM ioctl, we need to pick
one vcpu somehow.  Secondly, vcpu ioctl allows each vcpu to invoke this
ioctl in parallel.  It helps to scale regarding guest memory size, e.g.,
hundreds of GB.

[1] https://lore.kernel.org/kvm/Zbrj5WKVgMsUFDtb@google.com/
[2] https://lore.kernel.org/kvm/Ze-TJh0BBOWm9spT@google.com/

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Message-ID: <9a060293c9ad9a78f1d8994cfe1311e818e99257.1712785629.git.isaku.yamahata@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-07-12 11:17:35 -04:00
Johannes Berg
bc94745d04 um: remove pcap driver from documentation
We just removed the driver, but forgot the row in the
documentation table mentioning it. Remove that.

Link: https://patch.msgid.link/20240703172013.c3232dc5cbe9.I7f9941095d45a39d0f1e83680a408b3c6d445242@changeid
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-04 12:03:09 +02:00
Christoph Schlameuss
7816e58967 kvm: s390: Reject memory region operations for ucontrol VMs
This change rejects the KVM_SET_USER_MEMORY_REGION and
KVM_SET_USER_MEMORY_REGION2 ioctls when called on a ucontrol VM.
This is necessary since ucontrol VMs have kvm->arch.gmap set to 0 and
would thus result in a null pointer dereference further in.
Memory management needs to be performed in userspace and using the
ioctls KVM_S390_UCAS_MAP and KVM_S390_UCAS_UNMAP.

Also improve s390 specific documentation for KVM_SET_USER_MEMORY_REGION
and KVM_SET_USER_MEMORY_REGION2.

Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Fixes: 27e0393f15 ("KVM: s390: ucontrol: per vcpu address spaces")
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20240624095902.29375-1-schlameuss@linux.ibm.com
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
[frankja@linux.ibm.com: commit message spelling fix, subject prefix fix]
Message-ID: <20240624095902.29375-1-schlameuss@linux.ibm.com>
2024-07-04 09:07:24 +02:00
Changyuan Lyu
810ecbefdd KVM: Documentation: Correct the VGIC V2 CPU interface addr space size
In arch/arm64/include/uapi/asm/kvm.h, we have

  #define KVM_VGIC_V2_CPU_SIZE		0x2000

So the CPU interface address space should cover 8 KByte not 4 KByte.

Signed-off-by: Changyuan Lyu <changyuanl@google.com>
Link: https://lore.kernel.org/r/20240623164542.2999626-3-changyuanl@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-28 22:00:24 +00:00
Changyuan Lyu
03bd36a387 KVM: Documentation: Enumerate allowed value macros of irq_type
The expression `irq_type[n]` may confuse readers to interpret `n`
as the bit position and think of CPU = 1 << 0, SPI = 1 << 1, and
PPI = 1 << 2.

Since arch/arm64/include/uapi/asm/kvm.h already has macro definitions
for the allowed values, this commit uses these symbols to clear up
the ambiguity.

Signed-off-by: Changyuan Lyu <changyuanl@google.com>
Link: https://lore.kernel.org/r/20240623164542.2999626-2-changyuanl@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-28 22:00:18 +00:00
Changyuan Lyu
dc1d234cdd KVM: Documentation: Fix typo BFD
BDF is the acronym for Bus, Device, Function.

Signed-off-by: Changyuan Lyu <changyuanl@google.com>
Link: https://lore.kernel.org/r/20240623164542.2999626-1-changyuanl@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-06-28 22:00:13 +00:00
Michael Kelley
3b85a2eacd Documentation: hyperv: Add overview of Confidential Computing VM support
Add documentation topic for Confidential Computing (CoCo) VM support
in Linux guests on Hyper-V.

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Link: https://lore.kernel.org/r/20240618165059.10174-1-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20240618165059.10174-1-mhklinux@outlook.com>
2024-06-24 07:07:19 +00:00
Tom Lendacky
eb65f96cb3 virt: sev-guest: Choose the VMPCK key based on executing VMPL
Currently, the sev-guest driver uses the vmpck-0 key by default. When an
SVSM is present, the kernel is running at a VMPL other than 0 and the
vmpck-0 key is no longer available. If a specific vmpck key has not be
requested by the user via the vmpck_id module parameter, choose the
vmpck key based on the active VMPL level.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/b88081c5d88263176849df8ea93e90a404619cab.1717600736.git.thomas.lendacky@amd.com
2024-06-17 20:42:57 +02:00
Thomas Prescher
85542adb65 KVM: x86: Add KVM_RUN_X86_GUEST_MODE kvm_run flag
When a vCPU is interrupted by a signal while running a nested guest,
KVM will exit to userspace with L2 state. However, userspace has no
way to know whether it sees L1 or L2 state (besides calling
KVM_GET_STATS_FD, which does not have a stable ABI).

This causes multiple problems:

The simplest one is L2 state corruption when userspace marks the sregs
as dirty. See this mailing list thread [1] for a complete discussion.

Another problem is that if userspace decides to continue by emulating
instructions, it will unknowingly emulate with L2 state as if L1
doesn't exist, which can be considered a weird guest escape.

Introduce a new flag, KVM_RUN_X86_GUEST_MODE, in the kvm_run data
structure, which is set when the vCPU exited while running a nested
guest.  Also introduce a new capability, KVM_CAP_X86_GUEST_MODE, to
advertise the functionality to userspace.

[1] https://lore.kernel.org/kvm/20240416123558.212040-1-julian.stecklina@cyberus-technology.de/T/#m280aadcb2e10ae02c191a7dc4ed4b711a74b1f55

Signed-off-by: Thomas Prescher <thomas.prescher@cyberus-technology.de>
Signed-off-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
Link: https://lore.kernel.org/r/20240508132502.184428-1-julian.stecklina@cyberus-technology.de
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-06-11 09:24:31 -07:00
Carlos López
508f0c7bf6 KVM: x86: Improve documentation for KVM_CAP_X86_BUS_LOCK_EXIT
Improve the description for the KVM_CAP_X86_BUS_LOCK_EXIT capability to
fix a few typos and grammar issues, and to clarify the purpose of the
capability.

Signed-off-by: Carlos López <clopez@suse.de>
Link: https://lore.kernel.org/r/20240424105616.29596-1-clopez@suse.de
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-06-11 09:22:57 -07:00
Shivaprasad G Bhat
9a0d2f4995 KVM: PPC: Book3S HV: Add one-reg interface for HASHPKEYR register
The patch adds a one-reg register identifier which can be used to
read and set the virtual HASHPKEYR for the guest during enter/exit
with KVM_REG_PPC_HASHPKEYR. The specific SPR KVM API documentation
too updated.

Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/171759285547.1480.12374595786792346073.stgit@linux.ibm.com
2024-06-06 22:39:04 +10:00
Shivaprasad G Bhat
e9eb790b25 KVM: PPC: Book3S HV: Add one-reg interface for HASHKEYR register
The patch adds a one-reg register identifier which can be used to
read and set the virtual HASHKEYR for the guest during enter/exit
with KVM_REG_PPC_HASHKEYR. The specific SPR KVM API documentation
too updated.

Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/171759283170.1480.12904332463112769129.stgit@linux.ibm.com
2024-06-06 22:39:04 +10:00
Shivaprasad G Bhat
1a1e6865f5 KVM: PPC: Book3S HV: Add one-reg interface for DEXCR register
The patch adds a one-reg register identifier which can be used to
read and set the DEXCR for the guest during enter/exit with
KVM_REG_PPC_DEXCR. The specific SPR KVM API documentation
too updated.

Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/171759279613.1480.12873911783530175699.stgit@linux.ibm.com
2024-06-06 22:39:03 +10:00
Sean Christopherson
e1548088ff KVM: VMX: Drop support for forcing UC memory when guest CR0.CD=1
Drop KVM's emulation of CR0.CD=1 on Intel CPUs now that KVM no longer
honors guest MTRR memtypes, as forcing UC memory for VMs with
non-coherent DMA only makes sense if the guest is using something other
than PAT to configure the memtype for the DMA region.

Furthermore, KVM has forced WB memory for CR0.CD=1 since commit
fb279950ba ("KVM: vmx: obey KVM_QUIRK_CD_NW_CLEARED"), and no known
VMM in existence disables KVM_X86_QUIRK_CD_NW_CLEARED, let alone does
so with non-coherent DMA.

Lastly, commit fb279950ba ("KVM: vmx: obey KVM_QUIRK_CD_NW_CLEARED") was
from the same author as commit b18d5431ac ("KVM: x86: fix CR0.CD
virtualization"), and followed by a mere month.  I.e. forcing UC memory
was likely the result of code inspection or perhaps misdiagnosed failures,
and not the necessitate by a concrete use case.

Update KVM's documentation to note that KVM_X86_QUIRK_CD_NW_CLEARED is now
AMD-only, and to take an erratum for lack of CR0.CD virtualization on
Intel.

Tested-by: Xiangfei Ma <xiangfeix.ma@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20240309010929.1403984-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-06-05 08:13:14 -07:00
Sean Christopherson
0a7b73559b KVM: x86: Remove VMX support for virtualizing guest MTRR memtypes
Remove KVM's support for virtualizing guest MTRR memtypes, as full MTRR
adds no value, negatively impacts guest performance, and is a maintenance
burden due to it's complexity and oddities.

KVM's approach to virtualizating MTRRs make no sense, at all.  KVM *only*
honors guest MTRR memtypes if EPT is enabled *and* the guest has a device
that may perform non-coherent DMA access.  From a hardware virtualization
perspective of guest MTRRs, there is _nothing_ special about EPT.  Legacy
shadowing paging doesn't magically account for guest MTRRs, nor does NPT.

Unwinding and deciphering KVM's murky history, the MTRR virtualization
code appears to be the result of misdiagnosed issues when EPT + VT-d with
passthrough devices was enabled years and years ago.  And importantly, the
underlying bugs that were fudged around by honoring guest MTRR memtypes
have since been fixed (though rather poorly in some cases).

The zapping GFNs logic in the MTRR virtualization code came from:

  commit efdfe536d8
  Author: Xiao Guangrong <guangrong.xiao@linux.intel.com>
  Date:   Wed May 13 14:42:27 2015 +0800

    KVM: MMU: fix MTRR update

    Currently, whenever guest MTRR registers are changed
    kvm_mmu_reset_context is called to switch to the new root shadow page
    table, however, it's useless since:
    1) the cache type is not cached into shadow page's attribute so that
       the original root shadow page will be reused

    2) the cache type is set on the last spte, that means we should sync
       the last sptes when MTRR is changed

    This patch fixs this issue by drop all the spte in the gfn range which
    is being updated by MTRR

which was a fix for:

  commit 0bed3b568b
  Author:     Sheng Yang <sheng@linux.intel.com>
  AuthorDate: Thu Oct 9 16:01:54 2008 +0800
  Commit:     Avi Kivity <avi@redhat.com>
  CommitDate: Wed Dec 31 16:51:44 2008 +0200

      KVM: Improve MTRR structure

      As well as reset mmu context when set MTRR.

which was part of a "MTRR/PAT support for EPT" series that also added:

+       if (mt_mask) {
+               mt_mask = get_memory_type(vcpu, gfn) <<
+                         kvm_x86_ops->get_mt_mask_shift();
+               spte |= mt_mask;
+       }

where get_memory_type() was a truly gnarly helper to retrieve the guest
MTRR memtype for a given memtype.  And *very* subtly, at the time of that
change, KVM *always* set VMX_EPT_IGMT_BIT,

        kvm_mmu_set_base_ptes(VMX_EPT_READABLE_MASK |
                VMX_EPT_WRITABLE_MASK |
                VMX_EPT_DEFAULT_MT << VMX_EPT_MT_EPTE_SHIFT |
                VMX_EPT_IGMT_BIT);

which came in via:

  commit 928d4bf747
  Author:     Sheng Yang <sheng@linux.intel.com>
  AuthorDate: Thu Nov 6 14:55:45 2008 +0800
  Commit:     Avi Kivity <avi@redhat.com>
  CommitDate: Tue Nov 11 21:00:37 2008 +0200

      KVM: VMX: Set IGMT bit in EPT entry

      There is a potential issue that, when guest using pagetable without vmexit when
      EPT enabled, guest would use PAT/PCD/PWT bits to index PAT msr for it's memory,
      which would be inconsistent with host side and would cause host MCE due to
      inconsistent cache attribute.

      The patch set IGMT bit in EPT entry to ignore guest PAT and use WB as default
      memory type to protect host (notice that all memory mapped by KVM should be WB).

Note the CommitDates!  The AuthorDates strongly suggests Sheng Yang added
the whole "ignoreIGMT things as a bug fix for issues that were detected
during EPT + VT-d + passthrough enabling, but it was applied earlier
because it was a generic fix.

Jumping back to 0bed3b568b ("KVM: Improve MTRR structure"), the other
relevant code, or rather lack thereof, is the handling of *host* MMIO.
That fix came in a bit later, but given the author and timing, it's safe
to say it was all part of the same EPT+VT-d enabling mess.

  commit 2aaf69dcee
  Author:     Sheng Yang <sheng@linux.intel.com>
  AuthorDate: Wed Jan 21 16:52:16 2009 +0800
  Commit:     Avi Kivity <avi@redhat.com>
  CommitDate: Sun Feb 15 02:47:37 2009 +0200

    KVM: MMU: Map device MMIO as UC in EPT

    Software are not allow to access device MMIO using cacheable memory type, the
    patch limit MMIO region with UC and WC(guest can select WC using PAT and
    PCD/PWT).

In addition to the host MMIO and IGMT issues, KVM's MTRR virtualization
was obviously never tested on NPT until much later, which lends further
credence to the theory/argument that this was all the result of
misdiagnosed issues.

Discussion from the EPT+MTRR enabling thread[*] more or less confirms that
Sheng Yang was trying to resolve issues with passthrough MMIO.

 * Sheng Yang
  : Do you mean host(qemu) would access this memory and if we set it to guest
  : MTRR, host access would be broken? We would cover this in our shadow MTRR
  : patch, for we encountered this in video ram when doing some experiment with
  : VGA assignment.

And in the same thread, there's also what appears to be confirmation of
Intel running into issues with Windows XP related to a guest device driver
mapping DMA with WC in the PAT.

 * Avi Kavity
  : Sheng Yang wrote:
  : > Yes... But it's easy to do with assigned devices' mmio, but what if guest
  : > specific some non-mmio memory's memory type? E.g. we have met one issue in
  : > Xen, that a assigned-device's XP driver specific one memory region as buffer,
  : > and modify the memory type then do DMA.
  : >
  : > Only map MMIO space can be first step, but I guess we can modify assigned
  : > memory region memory type follow guest's?
  : >
  :
  : With ept/npt, we can't, since the memory type is in the guest's
  : pagetable entries, and these are not accessible.

[*] https://lore.kernel.org/all/1223539317-32379-1-git-send-email-sheng@linux.intel.com

So, for the most part, what likely happened is that 15 years ago, a few
engineers (a) fixed a #MC problem by ignoring guest PAT and (b) initially
"fixed" passthrough device MMIO by emulating *guest* MTRRs.  Except for
the below case, everything since then has been a result of those two
intertwined changes.

The one exception, which is actually yet more confirmation of all of the
above, is the revert of Paolo's attempt at "full" virtualization of guest
MTRRs:

  commit 606decd670
  Author: Paolo Bonzini <pbonzini@redhat.com>
  Date:   Thu Oct 1 13:12:47 2015 +0200

    Revert "KVM: x86: apply guest MTRR virtualization on host reserved pages"

    This reverts commit fd717f1101.
    It was reported to cause Machine Check Exceptions (bug 104091).

...

  commit fd717f1101
  Author: Paolo Bonzini <pbonzini@redhat.com>
  Date:   Tue Jul 7 14:38:13 2015 +0200

    KVM: x86: apply guest MTRR virtualization on host reserved pages

    Currently guest MTRR is avoided if kvm_is_reserved_pfn returns true.
    However, the guest could prefer a different page type than UC for
    such pages. A good example is that pass-throughed VGA frame buffer is
    not always UC as host expected.

    This patch enables full use of virtual guest MTRRs.

I.e. Paolo tried to add back KVM's behavior before "Map device MMIO as UC
in EPT" and got the same result: machine checks, likely due to the guest
MTRRs not being trustworthy/sane at all times.

Note, Paolo also tried to enable MTRR virtualization on SVM+NPT, but that
too got reverted.  Unfortunately, it doesn't appear that anyone ever found
a smoking gun, i.e. exactly why emulating guest MTRRs via NPT PAT caused
extremely slow boot times doesn't appear to have a definitive root cause.

  commit fc07e76ac7
  Author: Paolo Bonzini <pbonzini@redhat.com>
  Date:   Thu Oct 1 13:20:22 2015 +0200

    Revert "KVM: SVM: use NPT page attributes"

    This reverts commit 3c2e7f7de3.
    Initializing the mapping from MTRR to PAT values was reported to
    fail nondeterministically, and it also caused extremely slow boot
    (due to caching getting disabled---bug 103321) with assigned devices.

...

  commit 3c2e7f7de3
  Author: Paolo Bonzini <pbonzini@redhat.com>
  Date:   Tue Jul 7 14:32:17 2015 +0200

    KVM: SVM: use NPT page attributes

    Right now, NPT page attributes are not used, and the final page
    attribute depends solely on gPAT (which however is not synced
    correctly), the guest MTRRs and the guest page attributes.

    However, we can do better by mimicking what is done for VMX.
    In the absence of PCI passthrough, the guest PAT can be ignored
    and the page attributes can be just WB.  If passthrough is being
    used, instead, keep respecting the guest PAT, and emulate the guest
    MTRRs through the PAT field of the nested page tables.

    The only snag is that WP memory cannot be emulated correctly,
    because Linux's default PAT setting only includes the other types.

In short, honoring guest MTRRs for VMX was initially a workaround of
sorts for KVM ignoring guest PAT *and* for KVM not forcing UC for host
MMIO.  And while there *are* known cases where honoring guest MTRRs is
desirable, e.g. passthrough VGA frame buffers, the desired behavior in
that case is to get WC instead of UC, i.e. at this point it's for
performance, not correctness.

Furthermore, the complete absence of MTRR virtualization on NPT and
shadow paging proves that, while KVM theoretically can do better, it's
by no means necessary for correctnesss.

Lastly, since kernels mostly rely on firmware to do MTRR setup, and the
host typically provides guest firmware, honoring guest MTRRs is effectively
honoring *host* userspace memtypes, which is also backwards.  I.e. it
would be far better for host userspace to communicate its desired memtype
directly to KVM (or perhaps indirectly via VMAs in the host kernel), not
through guest MTRRs.

Tested-by: Xiangfei Ma <xiangfeix.ma@intel.com>
Tested-by: Yongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20240309010929.1403984-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-06-05 08:13:14 -07:00
Isaku Yamahata
6fef518594 KVM: x86: Add a capability to configure bus frequency for APIC timer
Add KVM_CAP_X86_APIC_BUS_CYCLES_NS capability to configure the APIC
bus clock frequency for APIC timer emulation.
Allow KVM_ENABLE_CAPABILITY(KVM_CAP_X86_APIC_BUS_CYCLES_NS) to set the
frequency in nanoseconds. When using this capability, the user space
VMM should configure CPUID leaf 0x15 to advertise the frequency.

Vishal reported that the TDX guest kernel expects a 25MHz APIC bus
frequency but ends up getting interrupts at a significantly higher rate.

The TDX architecture hard-codes the core crystal clock frequency to
25MHz and mandates exposing it via CPUID leaf 0x15. The TDX architecture
does not allow the VMM to override the value.

In addition, per Intel SDM:
    "The APIC timer frequency will be the processor’s bus clock or core
     crystal clock frequency (when TSC/core crystal clock ratio is
     enumerated in CPUID leaf 0x15) divided by the value specified in
     the divide configuration register."

The resulting 25MHz APIC bus frequency conflicts with the KVM hardcoded
APIC bus frequency of 1GHz.

The KVM doesn't enumerate CPUID leaf 0x15 to the guest unless the user
space VMM sets it using KVM_SET_CPUID. If the CPUID leaf 0x15 is
enumerated, the guest kernel uses it as the APIC bus frequency. If not,
the guest kernel measures the frequency based on other known timers like
the ACPI timer or the legacy PIT. As reported by Vishal the TDX guest
kernel expects a 25MHz timer frequency but gets timer interrupt more
frequently due to the 1GHz frequency used by KVM.

To ensure that the guest doesn't have a conflicting view of the APIC bus
frequency, allow the userspace to tell KVM to use the same frequency that
TDX mandates instead of the default 1Ghz.

Reported-by: Vishal Annapurve <vannapurve@google.com>
Closes: https://lore.kernel.org/lkml/20231006011255.4163884-1-vannapurve@google.com
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Co-developed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Yuan Yao <yuan.yao@intel.com>
Link: https://lore.kernel.org/r/6748a4c12269e756f0c48680da8ccc5367c31ce7.1714081726.git.reinette.chatre@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-06-05 06:18:27 -07:00
Paolo Bonzini
ab978c62e7 Merge branch 'kvm-6.11-sev-snp' into HEAD
Pull base x86 KVM support for running SEV-SNP guests from Michael Roth:

* add some basic infrastructure and introduces a new KVM_X86_SNP_VM
  vm_type to handle differences versus the existing KVM_X86_SEV_VM and
  KVM_X86_SEV_ES_VM types.

* implement the KVM API to handle the creation of a cryptographic
  launch context, encrypt/measure the initial image into guest memory,
  and finalize it before launching it.

* implement handling for various guest-generated events such as page
  state changes, onlining of additional vCPUs, etc.

* implement the gmem/mmu hooks needed to prepare gmem-allocated pages
  before mapping them into guest private memory ranges as well as
  cleaning them up prior to returning them to the host for use as
  normal memory. Because those cleanup hooks supplant certain
  activities like issuing WBINVDs during KVM MMU invalidations, avoid
  duplicating that work to avoid unecessary overhead.

This merge leaves out support support for attestation guest requests
and for loading the signing keys to be used for attestation requests.
2024-06-03 13:19:46 -04:00
Julian Stecklina
f2362c0475 KVM: fix documentation rendering for KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM
The documentation for KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM doesn't use the
correct keyword formatting, which breaks rendering on
https://www.kernel.org/doc/html/latest/virt/kvm/api.html.

Signed-off-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
Link: https://lore.kernel.org/r/20240520143220.340737-1-julian.stecklina@cyberus-technology.de
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-06-03 08:56:39 -07:00
Parshuram Sangle
f8aadead19 KVM: Update halt polling documentation to note that KVM has 4 module params
Update KVM's halt-polling documentation to correclty reflect that KVM has
4 relevant module params, not 3 params.

Co-developed-by: Rajendran Jaishankar <jaishankar.rajendran@intel.com>
Signed-off-by: Rajendran Jaishankar <jaishankar.rajendran@intel.com>
Signed-off-by: Parshuram Sangle <parshuram.sangle@intel.com>
Link: https://lore.kernel.org/r/20231102154628.2120-3-parshuram.sangle@intel.com
[sean: drop unrelated and misleading doc update]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-06-03 08:51:51 -07:00
Parshuram Sangle
aeb1b22a3a KVM: Enable halt polling shrink parameter by default
Default halt_poll_ns_shrink value of 0 always resets polling interval
to 0 on an un-successful poll where vcpu wakeup is not received. This is
mostly to avoid pointless polling for more number of shorter intervals. But
disabled shrink assumes vcpu wakeup is less likely to be received in
subsequent shorter polling intervals. Another side effect of 0 shrink value
is that, even on a successful poll if total block time was greater than
current polling interval, the polling interval starts over from 0 instead
of shrinking by a factor.

Enabling shrink with value of 2 allows the polling interval to gradually
decrement in case of un-successful poll events as well. This gives a fair
chance for successful polling events in subsequent polling intervals rather
than resetting it to 0 and starting over from grow_start.

Below kvm stat log snippet shows interleaved growth and shrinking of
polling interval:
87162647182125: kvm_halt_poll_ns: vcpu 0: halt_poll_ns 10000 (grow 0)
87162647637763: kvm_halt_poll_ns: vcpu 0: halt_poll_ns 20000 (grow 10000)
87162649627943: kvm_halt_poll_ns: vcpu 0: halt_poll_ns 40000 (grow 20000)
87162650892407: kvm_halt_poll_ns: vcpu 0: halt_poll_ns 20000 (shrink 40000)
87162651540378: kvm_halt_poll_ns: vcpu 0: halt_poll_ns 40000 (grow 20000)
87162652276768: kvm_halt_poll_ns: vcpu 0: halt_poll_ns 20000 (shrink 40000)
87162652515037: kvm_halt_poll_ns: vcpu 0: halt_poll_ns 40000 (grow 20000)
87162653383787: kvm_halt_poll_ns: vcpu 0: halt_poll_ns 20000 (shrink 40000)
87162653627670: kvm_halt_poll_ns: vcpu 0: halt_poll_ns 10000 (shrink 20000)
87162653796321: kvm_halt_poll_ns: vcpu 0: halt_poll_ns 20000 (grow 10000)
87162656171645: kvm_halt_poll_ns: vcpu 0: halt_poll_ns 10000 (shrink 20000)
87162661607487: kvm_halt_poll_ns: vcpu 0: halt_poll_ns 0 (shrink 10000)

Having both grow and shrink enabled creates a balance in polling interval
growth and shrink behavior. Tests show improved successful polling attempt
ratio which contribute to VM performance. Power penalty is quite negligible
as shrunk polling intervals create bursts of very short durations.

Performance assessment results show 3-6% improvements in CPU+GPU, Memory
and Storage Android VM workloads whereas 5-9% improvement in average FPS of
gaming VM workloads.

Power penalty is below 1% where host OS is either idle or running a
native workload having 2 VMs enabled. CPU/GPU intensive gaming workloads
as well do not show any increased power overhead with shrink enabled.

Co-developed-by: Rajendran Jaishankar <jaishankar.rajendran@intel.com>
Signed-off-by: Rajendran Jaishankar <jaishankar.rajendran@intel.com>
Signed-off-by: Parshuram Sangle <parshuram.sangle@intel.com>
Link: https://lore.kernel.org/r/20231102154628.2120-2-parshuram.sangle@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-06-03 08:49:10 -07:00
Michael Kelley
a0b134032e Documentation: hyperv: Improve synic and interrupt handling description
Current documentation does not describe how Linux handles the synthetic
interrupt controller (synic) that Hyper-V provides to guest VMs, nor how
VMBus or timer interrupts are handled. Add text describing the synic and
reorganize existing text to make this more clear.

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20240511133818.19649-2-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20240511133818.19649-2-mhklinux@outlook.com>
2024-05-28 05:28:42 +00:00
Michael Kelley
4c5a65fd10 Documentation: hyperv: Update spelling and fix typo
Update spelling from "VMbus" to "VMBus" to match Hyper-V product
documentation. Also correct typo: "SNP-SEV" should be "SEV-SNP".

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20240511133818.19649-1-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20240511133818.19649-1-mhklinux@outlook.com>
2024-05-28 05:28:42 +00:00
Linus Torvalds
ff2632d7d0 powerpc updates for 6.10
- Enable BPF Kernel Functions (kfuncs) in the powerpc BPF JIT.
 
  - Allow per-process DEXCR (Dynamic Execution Control Register) settings via
    prctl, notably NPHIE which controls hashst/hashchk for ROP protection.
 
  - Install powerpc selftests in sub-directories. Note this changes the way
    run_kselftest.sh needs to be invoked for powerpc selftests.
 
  - Change fadump (Firmware Assisted Dump) to better handle memory add/remove.
 
  - Add support for passing additional parameters to the fadump kernel.
 
  - Add support for updating the kdump image on CPU/memory add/remove events.
 
  - Other small features, cleanups and fixes.
 
 Thanks to: Andrew Donnellan, Andy Shevchenko, Aneesh Kumar K.V, Arnd Bergmann,
 Benjamin Gray, Bjorn Helgaas, Christian Zigotzky, Christophe Jaillet, Christophe
 Leroy, Colin Ian King, Cédric Le Goater, Dr. David Alan Gilbert, Erhard Furtner,
 Frank Li, GUO Zihua, Ganesh Goudar, Geoff Levand, Ghanshyam Agrawal, Greg Kurz,
 Hari Bathini, Joel Stanley, Justin Stitt, Kunwu Chan, Li Yang, Lidong Zhong,
 Madhavan Srinivasan, Mahesh Salgaonkar, Masahiro Yamada, Matthias Schiffer,
 Naresh Kamboju, Nathan Chancellor, Nathan Lynch, Naveen N Rao, Nicholas
 Miehlbradt, Ran Wang, Randy Dunlap, Ritesh Harjani, Sachin Sant, Shirisha Ganta,
 Shrikanth Hegde, Sourabh Jain, Stephen Rothwell, sundar, Thorsten Blum, Vaibhav
 Jain, Xiaowei Bao, Yang Li, Zhao Chenhui.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCAAxFiEEJFGtCPCthwEv2Y/bUevqPMjhpYAFAmZHLtwTHG1wZUBlbGxl
 cm1hbi5pZC5hdQAKCRBR6+o8yOGlgCGdD/0cqQkYl6+E0/K68Y7jnAWF+l0LNFlm
 /4jZ+zKXPiPhSdaQq4xo2ZjEooUPsm3c+AHidmrAtOMBULvv4pyciu61hrVu4Y2b
 aAudkBMUc+i/Lfaz7fq1KnN4LDFVm7xZZ+i/ju9tOBLMpOZ3YZ+YoOGA6nqsshJF
 XuB5h0T+H55he1wBpvyyrsUUyss53Mp3IsajxdwBOsUDDp0fSAg8SLEyhoiK3BsQ
 EjEa6iEqJSBheqFEXPvqsMuqM3k51CHe/pCOMODjo7P+u/MNrClZUscZKXGB5xq9
 Bu3SPxIYfRmU4XE53517faElEPmlxSBrjQGCD1EGEVXGsjn6r7TD6R5voow3SoUq
 CLTy90KNNrS1cIqeomu6bJ/anzYrViqTdekImA7Vb+Ol8f+uT9l+l1D75eYOKPQ3
 N0AHoa4rnWIb5kjCAjHaZ54O+B2q2tPlQqFUmt+BrvZyKS13zjE36stnArxP3MPC
 Xw6y3huX3AkZiJ4mQYRiBn//xGOLwrRCd/EoTDnoe08yq0Hoor6qIm4uEy2Nu3Kf
 0mBsEOxMsmQd6NEq43B/sFgVbbxKhAyxfZ9gHqxDQZcgoxXcMesyj/n4+jM5sRYK
 zmavLlykM2Tjlh1evs8+e0mCEwDjDn2GRlqstJQTrmnGhbMKi3jvw9I7gGtZVqbS
 kAflTXzsIXvxBA==
 =GoCV
 -----END PGP SIGNATURE-----

Merge tag 'powerpc-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Enable BPF Kernel Functions (kfuncs) in the powerpc BPF JIT.

 - Allow per-process DEXCR (Dynamic Execution Control Register) settings
   via prctl, notably NPHIE which controls hashst/hashchk for ROP
   protection.

 - Install powerpc selftests in sub-directories. Note this changes the
   way run_kselftest.sh needs to be invoked for powerpc selftests.

 - Change fadump (Firmware Assisted Dump) to better handle memory
   add/remove.

 - Add support for passing additional parameters to the fadump kernel.

 - Add support for updating the kdump image on CPU/memory add/remove
   events.

 - Other small features, cleanups and fixes.

Thanks to Andrew Donnellan, Andy Shevchenko, Aneesh Kumar K.V, Arnd
Bergmann, Benjamin Gray, Bjorn Helgaas, Christian Zigotzky, Christophe
Jaillet, Christophe Leroy, Colin Ian King, Cédric Le Goater, Dr. David
Alan Gilbert, Erhard Furtner, Frank Li, GUO Zihua, Ganesh Goudar, Geoff
Levand, Ghanshyam Agrawal, Greg Kurz, Hari Bathini, Joel Stanley, Justin
Stitt, Kunwu Chan, Li Yang, Lidong Zhong, Madhavan Srinivasan, Mahesh
Salgaonkar, Masahiro Yamada, Matthias Schiffer, Naresh Kamboju, Nathan
Chancellor, Nathan Lynch, Naveen N Rao, Nicholas Miehlbradt, Ran Wang,
Randy Dunlap, Ritesh Harjani, Sachin Sant, Shirisha Ganta, Shrikanth
Hegde, Sourabh Jain, Stephen Rothwell, sundar, Thorsten Blum, Vaibhav
Jain, Xiaowei Bao, Yang Li, and Zhao Chenhui.

* tag 'powerpc-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (85 commits)
  powerpc/fadump: Fix section mismatch warning
  powerpc/85xx: fix compile error without CONFIG_CRASH_DUMP
  powerpc/fadump: update documentation about bootargs_append
  powerpc/fadump: pass additional parameters when fadump is active
  powerpc/fadump: setup additional parameters for dump capture kernel
  powerpc/pseries/fadump: add support for multiple boot memory regions
  selftests/powerpc/dexcr: Fix spelling mistake "predicition" -> "prediction"
  KVM: PPC: Book3S HV nestedv2: Fix an error handling path in gs_msg_ops_kvmhv_nestedv2_config_fill_info()
  KVM: PPC: Fix documentation for ppc mmu caps
  KVM: PPC: code cleanup for kvmppc_book3s_irqprio_deliver
  KVM: PPC: Book3S HV nestedv2: Cancel pending DEC exception
  powerpc/xmon: Check cpu id in commands "c#", "dp#" and "dx#"
  powerpc/code-patching: Use dedicated memory routines for patching
  powerpc/code-patching: Test patch_instructions() during boot
  powerpc64/kasan: Pass virtual addresses to kasan_init_phys_region()
  powerpc: rename SPRN_HID2 define to SPRN_HID2_750FX
  powerpc: Fix typos
  powerpc/eeh: Fix spelling of the word "auxillary" and update comment
  macintosh/ams: Fix unused variable warning
  powerpc/Makefile: Remove bits related to the previous use of -mcmodel=large
  ...
2024-05-17 09:05:46 -07:00
Brijesh Singh
ad27ce1555 KVM: SEV: Add KVM_SEV_SNP_LAUNCH_FINISH command
Add a KVM_SEV_SNP_LAUNCH_FINISH command to finalize the cryptographic
launch digest which stores the measurement of the guest at launch time.
Also extend the existing SNP firmware data structures to support
disabling the use of Versioned Chip Endorsement Keys (VCEK) by guests as
part of this command.

While finalizing the launch flow, the code also issues the LAUNCH_UPDATE
SNP firmware commands to encrypt/measure the initial VMSA pages for each
configured vCPU, which requires setting the RMP entries for those pages
to private, so also add handling to clean up the RMP entries for these
pages whening freeing vCPUs during shutdown.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Co-developed-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Harald Hoyer <harald@profian.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Message-ID: <20240501085210.2213060-8-michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-05-12 04:09:30 -04:00