mirror of https://github.com/torvalds/linux.git
23 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
Sean Christopherson
|
7ea34578ae |
KVM: x86: Replace guts of "governed" features with comprehensive cpu_caps
Replace the internals of the governed features framework with a more comprehensive "guest CPU capabilities" implementation, i.e. with a guest version of kvm_cpu_caps. Keep the skeleton of governed features around for now as vmx_adjust_sec_exec_control() relies on detecting governed features to do the right thing for XSAVES, and switching all guest feature queries to guest_cpu_cap_has() requires subtle and non-trivial changes, i.e. is best done as a standalone change. Tracking *all* guest capabilities that KVM cares will allow excising the poorly named "governed features" framework, and effectively optimizes all KVM queries of guest capabilities, i.e. doesn't require making a subjective decision as to whether or not a feature is worth "governing", and doesn't require adding the code to do so. The cost of tracking all features is currently 92 bytes per vCPU on 64-bit kernels: 100 bytes for cpu_caps versus 8 bytes for governed_features. That cost is well worth paying even if the only benefit was eliminating the "governed features" terminology. And practically speaking, the real cost is zero unless those 92 bytes pushes the size of vcpu_vmx or vcpu_svm into a new order-N allocation, and if that happens there are better ways to reduce the footprint of kvm_vcpu_arch, e.g. making the PMU and/or MTRR state separate allocations. Suggested-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Link: https://lore.kernel.org/r/20241128013424.4096668-41-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> |
|
|
Sean Christopherson
|
6416b0fb16 |
KVM: x86: Do reverse CPUID sanity checks in __feature_leaf()
Do the compile-time sanity checks on reverse_cpuid in __feature_leaf() so that higher level APIs don't need to "manually" perform the sanity checks. No functional change intended. Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Link: https://lore.kernel.org/r/20241128013424.4096668-21-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> |
|
Tao Su
|
a0423af92c |
x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest
Latest Intel platform Clearwater Forest has introduced new instructions enumerated by CPUIDs of SHA512, SM3, SM4 and AVX-VNNI-INT16. Advertise these CPUIDs to userspace so that guests can query them directly. SHA512, SM3 and SM4 are on an expected-dense CPUID leaf and some other bits on this leaf have kernel usages. Considering they have not truly kernel usages, hide them in /proc/cpuinfo. These new instructions only operate in xmm, ymm registers and have no new VMX controls, so there is no additional host enabling required for guests to use these instructions, i.e. advertising these CPUIDs to userspace is safe. Tested-by: Jiaan Lu <jiaan.lu@intel.com> Tested-by: Xuelian Guo <xuelian.guo@intel.com> Signed-off-by: Tao Su <tao1.su@linux.intel.com> Message-ID: <20241105054825.870939-1-tao1.su@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
|
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Tao Su
|
1c450ffef5 |
KVM: x86: Advertise AVX10.1 CPUID to userspace
Advertise AVX10.1 related CPUIDs, i.e. report AVX10 support bit via
CPUID.(EAX=07H, ECX=01H):EDX[bit 19] and new CPUID leaf 0x24H so that
guest OS and applications can query the AVX10.1 CPUIDs directly. Intel
AVX10 represents the first major new vector ISA since the introduction of
Intel AVX512, which will establish a common, converged vector instruction
set across all Intel architectures[1].
AVX10.1 is an early version of AVX10, that enumerates the Intel AVX512
instruction set at 128, 256, and 512 bits which is enabled on
Granite Rapids. I.e., AVX10.1 is only a new CPUID enumeration with no
new functionality. New features, e.g. Embedded Rounding and Suppress
All Exceptions (SAE) will be introduced in AVX10.2.
Advertising AVX10.1 is safe because there is nothing to enable for AVX10.1,
i.e. it's purely a new way to enumerate support, thus there will never be
anything for the kernel to enable. Note just the CPUID checking is changed
when using AVX512 related instructions, e.g. if using one AVX512
instruction needs to check (AVX512 AND AVX512DQ), it can check
((AVX512 AND AVX512DQ) OR AVX10.1) after checking XCR0[7:5].
The versions of AVX10 are expected to be inclusive, e.g. version N+1 is
a superset of version N. Per the spec, the version can never be 0, just
advertise AVX10.1 if it's supported in hardware. Moreover, advertising
AVX10_{128,256,512} needs to land in the same commit as advertising basic
AVX10.1 support, otherwise KVM would advertise an impossible CPU model.
E.g. a CPU with AVX512 but not AVX10.1/512 is impossible per the SDM.
As more and more AVX related CPUIDs are added (it would have resulted in
around 40-50 CPUID flags when developing AVX10), the versioning approach
is introduced. But incrementing version numbers are bad for virtualization.
E.g. if AVX10.2 has a feature that shouldn't be enumerated to guests for
whatever reason, then KVM can't enumerate any "later" features either,
because the only way to hide the problematic AVX10.2 feature is to set the
version to AVX10.1 or lower[2]. But most AVX features are just passed
through and don't have virtualization controls, so AVX10 should not be
problematic in practice, so long as Intel honors their promise that future
versions will be supersets of past versions.
[1] https://cdrdv2.intel.com/v1/dl/getContent/784267
[2] https://lore.kernel.org/all/Zkz5Ak0PQlAN8DxK@google.com/
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Tao Su <tao1.su@linux.intel.com>
Link: https://lore.kernel.org/r/20240819062327.3269720-1-tao1.su@linux.intel.com
[sean: minor changelog tweaks]
Signed-off-by: Sean Christopherson <seanjc@google.com>
|
|
Linus Torvalds
|
2bb69f5fc7 |
x86 mitigations for the native BHI hardware vulnerabilty:
Branch History Injection (BHI) attacks may allow a malicious application to influence indirect branch prediction in kernel by poisoning the branch history. eIBRS isolates indirect branch targets in ring0. The BHB can still influence the choice of indirect branch predictor entry, and although branch predictor entries are isolated between modes when eIBRS is enabled, the BHB itself is not isolated between modes. Add mitigations against it either with the help of microcode or with software sequences for the affected CPUs. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmYUKPMTHHRnbHhAbGlu dXRyb25peC5kZQAKCRCmGPVMDXSYofT8EACJJix+GzGUcJjOvfWFZcxwziY152hO 5XSzHOZZL6oz5Yk/Rye/S9RVTN7aDjn1CEvI0cD/ULxaTP869sS9dDdUcHhEJ//5 6hjqWsWiKc1QmLjBy3Pcb97GZHQXM5a9D1f6jXnJD+0FMLbQHpzSEBit0H4tv/TC 75myGgYihvUbhN9/bL10M5fz+UADU42nChvPWDMr9ukljjCqa46tPTmKUIAW5TWj /xsyf+Nk+4kZpdaidKGhpof6KCV2rNeevvzUGN8Pv5y13iAmvlyplqTcQ6dlubnZ CuDX5Ji9spNF9WmhKpLgy5N+Ocb64oVHov98N2zw1sT1N8XOYcSM0fBj7SQIFURs L7T4jBZS+1c3ZGJPPFWIaGjV8w1ZMhelglwJxjY7ZgRD6fK3mwRx/ks54J8H4HjE FbirXaZLeKlscDIOKtnxxKoIGwpdGwLKQYi/wEw7F9NhCLSj9wMia+j3uYIUEEHr 6xEiYEtyjcV3ocxagH7eiHyrasOKG64vjx2h1XodusBA2Wrvgm/jXlchUu+wb6B4 LiiZJt+DmOdQ1h5j3r2rt3hw7+nWa7kyq34qfN6NSUCHiedp6q7BClueSaKiOCGk RoNibNiS+CqaxwGxj/RGuvajEJeEMCsLuCxzT3aeaDBsqscW6Ka/HkGA76Tpb5nJ E3JyjYE7AlG4rw== =W0W3 -----END PGP SIGNATURE----- Merge tag 'nativebhi' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mitigations from Thomas Gleixner: "Mitigations for the native BHI hardware vulnerabilty: Branch History Injection (BHI) attacks may allow a malicious application to influence indirect branch prediction in kernel by poisoning the branch history. eIBRS isolates indirect branch targets in ring0. The BHB can still influence the choice of indirect branch predictor entry, and although branch predictor entries are isolated between modes when eIBRS is enabled, the BHB itself is not isolated between modes. Add mitigations against it either with the help of microcode or with software sequences for the affected CPUs" [ This also ends up enabling the full mitigation by default despite the system call hardening, because apparently there are other indirect calls that are still sufficiently reachable, and the 'auto' case just isn't hardened enough. We'll have some more inevitable tweaking in the future - Linus ] * tag 'nativebhi' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: KVM: x86: Add BHI_NO x86/bhi: Mitigate KVM by default x86/bhi: Add BHI mitigation knob x86/bhi: Enumerate Branch History Injection (BHI) bug x86/bhi: Define SPEC_CTRL_BHI_DIS_S x86/bhi: Add support for clearing branch history at syscall entry x86/syscall: Don't force use of indirect calls for system calls x86/bugs: Change commas to semicolons in 'spectre_v2' sysfs file |
|
Daniel Sneddon
|
0f4a837615 |
x86/bhi: Define SPEC_CTRL_BHI_DIS_S
Newer processors supports a hardware control BHI_DIS_S to mitigate Branch History Injection (BHI). Setting BHI_DIS_S protects the kernel from userspace BHI attacks without having to manually overwrite the branch history. Define MSR_SPEC_CTRL bit BHI_DIS_S and its enumeration CPUID.BHI_CTRL. Mitigation is enabled later. Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> |
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Sean Christopherson
|
8cb4a9a82b |
x86/cpufeatures: Add CPUID_LNX_5 to track recently added Linux-defined word
Add CPUID_LNX_5 to track cpufeatures' word 21, and add the appropriate
compile-time assert in KVM to prevent direct lookups on the features in
CPUID_LNX_5. KVM uses X86_FEATURE_* flags to manage guest CPUID, and so
must translate features that are scattered by Linux from the Linux-defined
bit to the hardware-defined bit, i.e. should never try to directly access
scattered features in guest CPUID.
Opportunistically add NR_CPUID_WORDS to enum cpuid_leafs, along with a
compile-time assert in KVM's CPUID infrastructure to ensure that future
additions update cpuid_leafs along with NCAPINTS.
No functional change intended.
Fixes:
|
|
Jim Mattson
|
80c883db87 |
KVM: x86: Use a switch statement and macros in __feature_translate()
Use a switch statement with macro-generated case statements to handle
translating feature flags in order to reduce the probability of runtime
errors due to copy+paste goofs, to make compile-time errors easier to
debug, and to make the code more readable.
E.g. the compiler won't directly generate an error for duplicate if
statements
if (x86_feature == X86_FEATURE_SGX1)
return KVM_X86_FEATURE_SGX1;
else if (x86_feature == X86_FEATURE_SGX2)
return KVM_X86_FEATURE_SGX1;
and so instead reverse_cpuid_check() will fail due to the untranslated
entry pointing at a Linux-defined leaf, which provides practically no
hint as to what is broken
arch/x86/kvm/reverse_cpuid.h:108:2: error: call to __compiletime_assert_450 declared with 'error' attribute:
BUILD_BUG_ON failed: x86_leaf == CPUID_LNX_4
BUILD_BUG_ON(x86_leaf == CPUID_LNX_4);
^
whereas duplicate case statements very explicitly point at the offending
code:
arch/x86/kvm/reverse_cpuid.h:125:2: error: duplicate case value '361'
KVM_X86_TRANSLATE_FEATURE(SGX2);
^
arch/x86/kvm/reverse_cpuid.h:124:2: error: duplicate case value '360'
KVM_X86_TRANSLATE_FEATURE(SGX1);
^
And without macros, the opposite type of copy+paste goof doesn't generate
any error at compile-time, e.g. this yields no complaints:
case X86_FEATURE_SGX1:
return KVM_X86_FEATURE_SGX1;
case X86_FEATURE_SGX2:
return KVM_X86_FEATURE_SGX1;
Note, __feature_translate() is forcibly inlined and the feature is known
at compile-time, so the code generation between an if-elif sequence and a
switch statement should be identical.
Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://lore.kernel.org/r/20231024001636.890236-2-jmattson@google.com
[sean: use a macro, rewrite changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
|
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Jim Mattson
|
eefe5e6682 |
KVM: x86: Advertise CPUID.(EAX=7,ECX=2):EDX[5:0] to userspace
The low five bits {INTEL_PSFD, IPRED_CTRL, RRSBA_CTRL, DDPD_U, BHI_CTRL}
advertise the availability of specific bits in IA32_SPEC_CTRL. Since KVM
dynamically determines the legal IA32_SPEC_CTRL bits for the underlying
hardware, the hard work has already been done. Just let userspace know
that a guest can use these IA32_SPEC_CTRL bits.
The sixth bit (MCDT_NO) states that the processor does not exhibit MXCSR
Configuration Dependent Timing (MCDT) behavior. This is an inherent
property of the physical processor that is inherited by the virtual
CPU. Pass that information on to userspace.
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Chao Gao <chao.gao@intel.com>
Link: https://lore.kernel.org/r/20231024001636.890236-1-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
|
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Tao Su
|
99b6685453 |
KVM: x86: Advertise AMX-COMPLEX CPUID to userspace
Latest Intel platform GraniteRapids-D introduces AMX-COMPLEX, which adds two instructions to perform matrix multiplication of two tiles containing complex elements and accumulate the results into a packed single precision tile. AMX-COMPLEX is enumerated via CPUID.(EAX=7,ECX=1):EDX[bit 8] Advertise AMX_COMPLEX if it's supported in hardware. There are no VMX controls for the feature, i.e. the instructions can't be interecepted, and KVM advertises base AMX in CPUID if AMX is supported in hardware, even if KVM doesn't advertise AMX as being supported in XCR0, e.g. because the process didn't opt-in to allocating tile data. Signed-off-by: Tao Su <tao1.su@linux.intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Link: https://lore.kernel.org/r/20230802022954.193843-1-tao1.su@linux.intel.com [sean: tweak last paragraph of changelog] Signed-off-by: Sean Christopherson <seanjc@google.com> |
|
Like Xu
|
fe8d76c1a6 |
KVM: x86/cpuid: Add a KVM-only leaf to redirect AMD PerfMonV2 flag
Add a KVM-only leaf for AMD's PerfMonV2 to redirect the kernel's scattered version to its architectural location, e.g. so that KVM can query guest support via guest_cpuid_has(). Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Like Xu <likexu@tencent.com> [sean: massage changelog] Link: https://lore.kernel.org/r/20230603011058.1038821-11-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> |
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Linus Torvalds
|
49d5759268 |
ARM:
- Provide a virtual cache topology to the guest to avoid
inconsistencies with migration on heterogenous systems. Non secure
software has no practical need to traverse the caches by set/way in
the first place.
- Add support for taking stage-2 access faults in parallel. This was an
accidental omission in the original parallel faults implementation,
but should provide a marginal improvement to machines w/o FEAT_HAFDBS
(such as hardware from the fruit company).
- A preamble to adding support for nested virtualization to KVM,
including vEL2 register state, rudimentary nested exception handling
and masking unsupported features for nested guests.
- Fixes to the PSCI relay that avoid an unexpected host SVE trap when
resuming a CPU when running pKVM.
- VGIC maintenance interrupt support for the AIC
- Improvements to the arch timer emulation, primarily aimed at reducing
the trap overhead of running nested.
- Add CONFIG_USERFAULTFD to the KVM selftests config fragment in the
interest of CI systems.
- Avoid VM-wide stop-the-world operations when a vCPU accesses its own
redistributor.
- Serialize when toggling CPACR_EL1.SMEN to avoid unexpected exceptions
in the host.
- Aesthetic and comment/kerneldoc fixes
- Drop the vestiges of the old Columbia mailing list and add [Oliver]
as co-maintainer
This also drags in arm64's 'for-next/sme2' branch, because both it and
the PSCI relay changes touch the EL2 initialization code.
RISC-V:
- Fix wrong usage of PGDIR_SIZE instead of PUD_SIZE
- Correctly place the guest in S-mode after redirecting a trap to the guest
- Redirect illegal instruction traps to guest
- SBI PMU support for guest
s390:
- Two patches sorting out confusion between virtual and physical
addresses, which currently are the same on s390.
- A new ioctl that performs cmpxchg on guest memory
- A few fixes
x86:
- Change tdp_mmu to a read-only parameter
- Separate TDP and shadow MMU page fault paths
- Enable Hyper-V invariant TSC control
- Fix a variety of APICv and AVIC bugs, some of them real-world,
some of them affecting architecurally legal but unlikely to
happen in practice
- Mark APIC timer as expired if its in one-shot mode and the count
underflows while the vCPU task was being migrated
- Advertise support for Intel's new fast REP string features
- Fix a double-shootdown issue in the emergency reboot code
- Ensure GIF=1 and disable SVM during an emergency reboot, i.e. give SVM
similar treatment to VMX
- Update Xen's TSC info CPUID sub-leaves as appropriate
- Add support for Hyper-V's extended hypercalls, where "support" at this
point is just forwarding the hypercalls to userspace
- Clean up the kvm->lock vs. kvm->srcu sequences when updating the PMU and
MSR filters
- One-off fixes and cleanups
- Fix and cleanup the range-based TLB flushing code, used when KVM is
running on Hyper-V
- Add support for filtering PMU events using a mask. If userspace
wants to restrict heavily what events the guest can use, it can now
do so without needing an absurd number of filter entries
- Clean up KVM's handling of "PMU MSRs to save", especially when vPMU
support is disabled
- Add PEBS support for Intel Sapphire Rapids
- Fix a mostly benign overflow bug in SEV's send|receive_update_data()
- Move several SVM-specific flags into vcpu_svm
x86 Intel:
- Handle NMI VM-Exits before leaving the noinstr region
- A few trivial cleanups in the VM-Enter flows
- Stop enabling VMFUNC for L1 purely to document that KVM doesn't support
EPTP switching (or any other VM function) for L1
- Fix a crash when using eVMCS's enlighted MSR bitmaps
Generic:
- Clean up the hardware enable and initialization flow, which was
scattered around multiple arch-specific hooks. Instead, just
let the arch code call into generic code. Both x86 and ARM should
benefit from not having to fight common KVM code's notion of how
to do initialization.
- Account allocations in generic kvm_arch_alloc_vm()
- Fix a memory leak if coalesced MMIO unregistration fails
selftests:
- On x86, cache the CPU vendor (AMD vs. Intel) and use the info to emit
the correct hypercall instruction instead of relying on KVM to patch
in VMMCALL
- Use TAP interface for kvm_binary_stats_test and tsc_msrs_test
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
"ARM:
- Provide a virtual cache topology to the guest to avoid
inconsistencies with migration on heterogenous systems. Non secure
software has no practical need to traverse the caches by set/way in
the first place
- Add support for taking stage-2 access faults in parallel. This was
an accidental omission in the original parallel faults
implementation, but should provide a marginal improvement to
machines w/o FEAT_HAFDBS (such as hardware from the fruit company)
- A preamble to adding support for nested virtualization to KVM,
including vEL2 register state, rudimentary nested exception
handling and masking unsupported features for nested guests
- Fixes to the PSCI relay that avoid an unexpected host SVE trap when
resuming a CPU when running pKVM
- VGIC maintenance interrupt support for the AIC
- Improvements to the arch timer emulation, primarily aimed at
reducing the trap overhead of running nested
- Add CONFIG_USERFAULTFD to the KVM selftests config fragment in the
interest of CI systems
- Avoid VM-wide stop-the-world operations when a vCPU accesses its
own redistributor
- Serialize when toggling CPACR_EL1.SMEN to avoid unexpected
exceptions in the host
- Aesthetic and comment/kerneldoc fixes
- Drop the vestiges of the old Columbia mailing list and add [Oliver]
as co-maintainer
RISC-V:
- Fix wrong usage of PGDIR_SIZE instead of PUD_SIZE
- Correctly place the guest in S-mode after redirecting a trap to the
guest
- Redirect illegal instruction traps to guest
- SBI PMU support for guest
s390:
- Sort out confusion between virtual and physical addresses, which
currently are the same on s390
- A new ioctl that performs cmpxchg on guest memory
- A few fixes
x86:
- Change tdp_mmu to a read-only parameter
- Separate TDP and shadow MMU page fault paths
- Enable Hyper-V invariant TSC control
- Fix a variety of APICv and AVIC bugs, some of them real-world, some
of them affecting architecurally legal but unlikely to happen in
practice
- Mark APIC timer as expired if its in one-shot mode and the count
underflows while the vCPU task was being migrated
- Advertise support for Intel's new fast REP string features
- Fix a double-shootdown issue in the emergency reboot code
- Ensure GIF=1 and disable SVM during an emergency reboot, i.e. give
SVM similar treatment to VMX
- Update Xen's TSC info CPUID sub-leaves as appropriate
- Add support for Hyper-V's extended hypercalls, where "support" at
this point is just forwarding the hypercalls to userspace
- Clean up the kvm->lock vs. kvm->srcu sequences when updating the
PMU and MSR filters
- One-off fixes and cleanups
- Fix and cleanup the range-based TLB flushing code, used when KVM is
running on Hyper-V
- Add support for filtering PMU events using a mask. If userspace
wants to restrict heavily what events the guest can use, it can now
do so without needing an absurd number of filter entries
- Clean up KVM's handling of "PMU MSRs to save", especially when vPMU
support is disabled
- Add PEBS support for Intel Sapphire Rapids
- Fix a mostly benign overflow bug in SEV's
send|receive_update_data()
- Move several SVM-specific flags into vcpu_svm
x86 Intel:
- Handle NMI VM-Exits before leaving the noinstr region
- A few trivial cleanups in the VM-Enter flows
- Stop enabling VMFUNC for L1 purely to document that KVM doesn't
support EPTP switching (or any other VM function) for L1
- Fix a crash when using eVMCS's enlighted MSR bitmaps
Generic:
- Clean up the hardware enable and initialization flow, which was
scattered around multiple arch-specific hooks. Instead, just let
the arch code call into generic code. Both x86 and ARM should
benefit from not having to fight common KVM code's notion of how to
do initialization
- Account allocations in generic kvm_arch_alloc_vm()
- Fix a memory leak if coalesced MMIO unregistration fails
selftests:
- On x86, cache the CPU vendor (AMD vs. Intel) and use the info to
emit the correct hypercall instruction instead of relying on KVM to
patch in VMMCALL
- Use TAP interface for kvm_binary_stats_test and tsc_msrs_test"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (325 commits)
KVM: SVM: hyper-v: placate modpost section mismatch error
KVM: x86/mmu: Make tdp_mmu_allowed static
KVM: arm64: nv: Use reg_to_encoding() to get sysreg ID
KVM: arm64: nv: Only toggle cache for virtual EL2 when SCTLR_EL2 changes
KVM: arm64: nv: Filter out unsupported features from ID regs
KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2
KVM: arm64: nv: Allow a sysreg to be hidden from userspace only
KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor
KVM: arm64: nv: Add accessors for SPSR_EL1, ELR_EL1 and VBAR_EL1 from virtual EL2
KVM: arm64: nv: Handle SMCs taken from virtual EL2
KVM: arm64: nv: Handle trapped ERET from virtual EL2
KVM: arm64: nv: Inject HVC exceptions to the virtual EL2
KVM: arm64: nv: Support virtual EL2 exceptions
KVM: arm64: nv: Handle HCR_EL2.NV system register traps
KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state
KVM: arm64: nv: Add EL2 system registers to vcpu context
KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x
KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set
KVM: arm64: nv: Introduce nested virtualization VCPU feature
KVM: arm64: Use the S2 MMU context to iterate over S2 table
...
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Kim Phillips
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8415a74852 |
x86/cpu, kvm: Add support for CPUID_80000021_EAX
Add support for CPUID leaf 80000021, EAX. The majority of the features will be used in the kernel and thus a separate leaf is appropriate. Include KVM's reverse_cpuid entry because features are used by VM guests, too. [ bp: Massage commit message. ] Signed-off-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20230124163319.2277355-2-kim.phillips@amd.com |
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Paolo Bonzini
|
fc471e8310 |
Merge branch 'kvm-late-6.1' into HEAD
x86: * Change tdp_mmu to a read-only parameter * Separate TDP and shadow MMU page fault paths * Enable Hyper-V invariant TSC control selftests: * Use TAP interface for kvm_binary_stats_test and tsc_msrs_test Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Vitaly Kuznetsov
|
0fcf86f05a |
KVM: x86: Add a KVM-only leaf for CPUID_8000_0007_EDX
CPUID_8000_0007_EDX may come handy when X86_FEATURE_CONSTANT_TSC needs to be checked. No functional change intended. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221013095849.705943-3-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
|
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Linus Torvalds
|
8fa590bf34 |
ARM64:
* Enable the per-vcpu dirty-ring tracking mechanism, together with an
option to keep the good old dirty log around for pages that are
dirtied by something other than a vcpu.
* Switch to the relaxed parallel fault handling, using RCU to delay
page table reclaim and giving better performance under load.
* Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping option,
which multi-process VMMs such as crosvm rely on (see merge commit 382b5b87a97d:
"Fix a number of issues with MTE, such as races on the tags being
initialised vs the PG_mte_tagged flag as well as the lack of support
for VM_SHARED when KVM is involved. Patches from Catalin Marinas and
Peter Collingbourne").
* Merge the pKVM shadow vcpu state tracking that allows the hypervisor
to have its own view of a vcpu, keeping that state private.
* Add support for the PMUv3p5 architecture revision, bringing support
for 64bit counters on systems that support it, and fix the
no-quite-compliant CHAIN-ed counter support for the machines that
actually exist out there.
* Fix a handful of minor issues around 52bit VA/PA support (64kB pages
only) as a prefix of the oncoming support for 4kB and 16kB pages.
* Pick a small set of documentation and spelling fixes, because no
good merge window would be complete without those.
s390:
* Second batch of the lazy destroy patches
* First batch of KVM changes for kernel virtual != physical address support
* Removal of a unused function
x86:
* Allow compiling out SMM support
* Cleanup and documentation of SMM state save area format
* Preserve interrupt shadow in SMM state save area
* Respond to generic signals during slow page faults
* Fixes and optimizations for the non-executable huge page errata fix.
* Reprogram all performance counters on PMU filter change
* Cleanups to Hyper-V emulation and tests
* Process Hyper-V TLB flushes from a nested guest (i.e. from a L2 guest
running on top of a L1 Hyper-V hypervisor)
* Advertise several new Intel features
* x86 Xen-for-KVM:
** Allow the Xen runstate information to cross a page boundary
** Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured
** Add support for 32-bit guests in SCHEDOP_poll
* Notable x86 fixes and cleanups:
** One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0).
** Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few
years back when eliminating unnecessary barriers when switching between
vmcs01 and vmcs02.
** Clean up vmread_error_trampoline() to make it more obvious that params
must be passed on the stack, even for x86-64.
** Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective
of the current guest CPUID.
** Fudge around a race with TSC refinement that results in KVM incorrectly
thinking a guest needs TSC scaling when running on a CPU with a
constant TSC, but no hardware-enumerated TSC frequency.
** Advertise (on AMD) that the SMM_CTL MSR is not supported
** Remove unnecessary exports
Generic:
* Support for responding to signals during page faults; introduces
new FOLL_INTERRUPTIBLE flag that was reviewed by mm folks
Selftests:
* Fix an inverted check in the access tracking perf test, and restore
support for asserting that there aren't too many idle pages when
running on bare metal.
* Fix build errors that occur in certain setups (unsure exactly what is
unique about the problematic setup) due to glibc overriding
static_assert() to a variant that requires a custom message.
* Introduce actual atomics for clear/set_bit() in selftests
* Add support for pinning vCPUs in dirty_log_perf_test.
* Rename the so called "perf_util" framework to "memstress".
* Add a lightweight psuedo RNG for guest use, and use it to randomize
the access pattern and write vs. read percentage in the memstress tests.
* Add a common ucall implementation; code dedup and pre-work for running
SEV (and beyond) guests in selftests.
* Provide a common constructor and arch hook, which will eventually be
used by x86 to automatically select the right hypercall (AMD vs. Intel).
* A bunch of added/enabled/fixed selftests for ARM64, covering memslots,
breakpoints, stage-2 faults and access tracking.
* x86-specific selftest changes:
** Clean up x86's page table management.
** Clean up and enhance the "smaller maxphyaddr" test, and add a related
test to cover generic emulation failure.
** Clean up the nEPT support checks.
** Add X86_PROPERTY_* framework to retrieve multi-bit CPUID values.
** Fix an ordering issue in the AMX test introduced by recent conversions
to use kvm_cpu_has(), and harden the code to guard against similar bugs
in the future. Anything that tiggers caching of KVM's supported CPUID,
kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if
the caching occurs before the test opts in via prctl().
Documentation:
* Remove deleted ioctls from documentation
* Clean up the docs for the x86 MSR filter.
* Various fixes
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
"ARM64:
- Enable the per-vcpu dirty-ring tracking mechanism, together with an
option to keep the good old dirty log around for pages that are
dirtied by something other than a vcpu.
- Switch to the relaxed parallel fault handling, using RCU to delay
page table reclaim and giving better performance under load.
- Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping
option, which multi-process VMMs such as crosvm rely on (see merge
commit 382b5b87a97d: "Fix a number of issues with MTE, such as
races on the tags being initialised vs the PG_mte_tagged flag as
well as the lack of support for VM_SHARED when KVM is involved.
Patches from Catalin Marinas and Peter Collingbourne").
- Merge the pKVM shadow vcpu state tracking that allows the
hypervisor to have its own view of a vcpu, keeping that state
private.
- Add support for the PMUv3p5 architecture revision, bringing support
for 64bit counters on systems that support it, and fix the
no-quite-compliant CHAIN-ed counter support for the machines that
actually exist out there.
- Fix a handful of minor issues around 52bit VA/PA support (64kB
pages only) as a prefix of the oncoming support for 4kB and 16kB
pages.
- Pick a small set of documentation and spelling fixes, because no
good merge window would be complete without those.
s390:
- Second batch of the lazy destroy patches
- First batch of KVM changes for kernel virtual != physical address
support
- Removal of a unused function
x86:
- Allow compiling out SMM support
- Cleanup and documentation of SMM state save area format
- Preserve interrupt shadow in SMM state save area
- Respond to generic signals during slow page faults
- Fixes and optimizations for the non-executable huge page errata
fix.
- Reprogram all performance counters on PMU filter change
- Cleanups to Hyper-V emulation and tests
- Process Hyper-V TLB flushes from a nested guest (i.e. from a L2
guest running on top of a L1 Hyper-V hypervisor)
- Advertise several new Intel features
- x86 Xen-for-KVM:
- Allow the Xen runstate information to cross a page boundary
- Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured
- Add support for 32-bit guests in SCHEDOP_poll
- Notable x86 fixes and cleanups:
- One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0).
- Reinstate IBPB on emulated VM-Exit that was incorrectly dropped
a few years back when eliminating unnecessary barriers when
switching between vmcs01 and vmcs02.
- Clean up vmread_error_trampoline() to make it more obvious that
params must be passed on the stack, even for x86-64.
- Let userspace set all supported bits in MSR_IA32_FEAT_CTL
irrespective of the current guest CPUID.
- Fudge around a race with TSC refinement that results in KVM
incorrectly thinking a guest needs TSC scaling when running on a
CPU with a constant TSC, but no hardware-enumerated TSC
frequency.
- Advertise (on AMD) that the SMM_CTL MSR is not supported
- Remove unnecessary exports
Generic:
- Support for responding to signals during page faults; introduces
new FOLL_INTERRUPTIBLE flag that was reviewed by mm folks
Selftests:
- Fix an inverted check in the access tracking perf test, and restore
support for asserting that there aren't too many idle pages when
running on bare metal.
- Fix build errors that occur in certain setups (unsure exactly what
is unique about the problematic setup) due to glibc overriding
static_assert() to a variant that requires a custom message.
- Introduce actual atomics for clear/set_bit() in selftests
- Add support for pinning vCPUs in dirty_log_perf_test.
- Rename the so called "perf_util" framework to "memstress".
- Add a lightweight psuedo RNG for guest use, and use it to randomize
the access pattern and write vs. read percentage in the memstress
tests.
- Add a common ucall implementation; code dedup and pre-work for
running SEV (and beyond) guests in selftests.
- Provide a common constructor and arch hook, which will eventually
be used by x86 to automatically select the right hypercall (AMD vs.
Intel).
- A bunch of added/enabled/fixed selftests for ARM64, covering
memslots, breakpoints, stage-2 faults and access tracking.
- x86-specific selftest changes:
- Clean up x86's page table management.
- Clean up and enhance the "smaller maxphyaddr" test, and add a
related test to cover generic emulation failure.
- Clean up the nEPT support checks.
- Add X86_PROPERTY_* framework to retrieve multi-bit CPUID values.
- Fix an ordering issue in the AMX test introduced by recent
conversions to use kvm_cpu_has(), and harden the code to guard
against similar bugs in the future. Anything that tiggers
caching of KVM's supported CPUID, kvm_cpu_has() in this case,
effectively hides opt-in XSAVE features if the caching occurs
before the test opts in via prctl().
Documentation:
- Remove deleted ioctls from documentation
- Clean up the docs for the x86 MSR filter.
- Various fixes"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (361 commits)
KVM: x86: Add proper ReST tables for userspace MSR exits/flags
KVM: selftests: Allocate ucall pool from MEM_REGION_DATA
KVM: arm64: selftests: Align VA space allocator with TTBR0
KVM: arm64: Fix benign bug with incorrect use of VA_BITS
KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow
KVM: x86: Advertise that the SMM_CTL MSR is not supported
KVM: x86: remove unnecessary exports
KVM: selftests: Fix spelling mistake "probabalistic" -> "probabilistic"
tools: KVM: selftests: Convert clear/set_bit() to actual atomics
tools: Drop "atomic_" prefix from atomic test_and_set_bit()
tools: Drop conflicting non-atomic test_and_{clear,set}_bit() helpers
KVM: selftests: Use non-atomic clear/set bit helpers in KVM tests
perf tools: Use dedicated non-atomic clear/set bit helpers
tools: Take @bit as an "unsigned long" in {clear,set}_bit() helpers
KVM: arm64: selftests: Enable single-step without a "full" ucall()
KVM: x86: fix APICv/x2AVIC disabled when vm reboot by itself
KVM: Remove stale comment about KVM_REQ_UNHALT
KVM: Add missing arch for KVM_CREATE_DEVICE and KVM_{SET,GET}_DEVICE_ATTR
KVM: Reference to kvm_userspace_memory_region in doc and comments
KVM: Delete all references to removed KVM_SET_MEMORY_ALIAS ioctl
...
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Jiaxi Chen
|
29c46979b2 |
KVM: x86: Advertise PREFETCHIT0/1 CPUID to user space
Latest Intel platform Granite Rapids has introduced a new instruction - PREFETCHIT0/1, which moves code to memory (cache) closer to the processor depending on specific hints. The bit definition: CPUID.(EAX=7,ECX=1):EDX[bit 14] PREFETCHIT0/1 is on a KVM-only subleaf. Plus an x86_FEATURE definition for this feature bit to direct it to the KVM entry. Advertise PREFETCHIT0/1 to KVM userspace. This is safe because there are no new VMX controls or additional host enabling required for guests to use this feature. Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com> Message-Id: <20221125125845.1182922-9-jiaxi.chen@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
|
|
Jiaxi Chen
|
9977f0877d |
KVM: x86: Advertise AVX-NE-CONVERT CPUID to user space
AVX-NE-CONVERT is a new set of instructions which can convert low precision floating point like BF16/FP16 to high precision floating point FP32, and can also convert FP32 elements to BF16. This instruction allows the platform to have improved AI capabilities and better compatibility. The bit definition: CPUID.(EAX=7,ECX=1):EDX[bit 5] AVX-NE-CONVERT is on a KVM-only subleaf. Plus an x86_FEATURE definition for this feature bit to direct it to the KVM entry. Advertise AVX-NE-CONVERT to KVM userspace. This is safe because there are no new VMX controls or additional host enabling required for guests to use this feature. Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com> Message-Id: <20221125125845.1182922-8-jiaxi.chen@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
|
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Jiaxi Chen
|
24d74b9f5f |
KVM: x86: Advertise AVX-VNNI-INT8 CPUID to user space
AVX-VNNI-INT8 is a new set of instructions in the latest Intel platform Sierra Forest, aims for the platform to have superior AI capabilities. This instruction multiplies the individual bytes of two unsigned or unsigned source operands, then adds and accumulates the results into the destination dword element size operand. The bit definition: CPUID.(EAX=7,ECX=1):EDX[bit 4] AVX-VNNI-INT8 is on a new and sparse CPUID leaf and all bits on this leaf have no truly kernel use case for now. Given that and to save space for kernel feature bits, move this new leaf to KVM-only subleaf and plus an x86_FEATURE definition for AVX-VNNI-INT8 to direct it to the KVM entry. Advertise AVX-VNNI-INT8 to KVM userspace. This is safe because there are no new VMX controls or additional host enabling required for guests to use this feature. Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com> Message-Id: <20221125125845.1182922-7-jiaxi.chen@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Sean Christopherson
|
047c722990 |
KVM: x86: Update KVM-only leaf handling to allow for 100% KVM-only leafs
Rename kvm_cpu_cap_init_scattered() to kvm_cpu_cap_init_kvm_defined() in anticipation of adding KVM-only CPUID leafs that aren't recognized by the kernel and thus not scattered, i.e. for leafs that are 100% KVM-defined. Adjust/add comments to kvm_only_cpuid_leafs and KVM_X86_FEATURE to document how to create new kvm_only_cpuid_leafs entries for scattered features as well as features that are entirely unknown to the kernel. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221125125845.1182922-3-jiaxi.chen@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
|
Kai Huang
|
16a7fe3728 |
KVM/VMX: Allow exposing EDECCSSA user leaf function to KVM guest
The new Asynchronous Exit (AEX) notification mechanism (AEX-notify) allows one enclave to receive a notification in the ERESUME after the enclave exit due to an AEX. EDECCSSA is a new SGX user leaf function (ENCLU[EDECCSSA]) to facilitate the AEX notification handling. The new EDECCSSA is enumerated via CPUID(EAX=0x12,ECX=0x0):EAX[11]. Besides Allowing reporting the new AEX-notify attribute to KVM guests, also allow reporting the new EDECCSSA user leaf function to KVM guests so the guest can fully utilize the AEX-notify mechanism. Similar to existing X86_FEATURE_SGX1 and X86_FEATURE_SGX2, introduce a new scattered X86_FEATURE_SGX_EDECCSSA bit for the new EDECCSSA, and report it in KVM's supported CPUIDs. Note, no additional KVM enabling is required to allow the guest to use EDECCSSA. It's impossible to trap ENCLU (without completely preventing the guest from using SGX). Advertise EDECCSSA as supported purely so that userspace doesn't need to special case EDECCSSA, i.e. doesn't need to manually check host CPUID. The inability to trap ENCLU also means that KVM can't prevent the guest from using EDECCSSA, but that virtualization hole is benign as far as KVM is concerned. EDECCSSA is simply a fancy way to modify internal enclave state. More background about how do AEX-notify and EDECCSSA work: SGX maintains a Current State Save Area Frame (CSSA) for each enclave thread. When AEX happens, the enclave thread context is saved to the CSSA and the CSSA is increased by 1. For a normal ERESUME which doesn't deliver AEX notification, it restores the saved thread context from the previously saved SSA and decreases the CSSA. If AEX-notify is enabled for one enclave, the ERESUME acts differently. Instead of restoring the saved thread context and decreasing the CSSA, it acts like EENTER which doesn't decrease the CSSA but establishes a clean slate thread context using the CSSA for the enclave to handle the notification. After some handling, the enclave must discard the "new-established" SSA and switch back to the previously saved SSA (upon AEX). Otherwise, the enclave will run out of SSA space upon further AEXs and eventually fail to run. To solve this problem, the new EDECCSSA essentially decreases the CSSA. It can be used by the enclave notification handler to switch back to the previous saved SSA when needed, i.e. after it handles the notification. Signed-off-by: Kai Huang <kai.huang@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Sean Christopherson <seanjc@google.com> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Link: https://lore.kernel.org/all/20221101022422.858944-1-kai.huang%40intel.com |
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Paolo Bonzini
|
d9db0fd6c5 |
KVM: SEV: Mask CPUID[0x8000001F].eax according to supported features
Add a reverse-CPUID entry for the memory encryption word, 0x8000001F.EAX, and use it to override the supported CPUID flags reported to userspace. Masking the reported CPUID flags avoids over-reporting KVM support, e.g. without the mask a SEV-SNP capable CPU may incorrectly advertise SNP support to userspace. Clear SEV/SEV-ES if their corresponding module parameters are disabled, and clear the memory encryption leaf completely if SEV is not fully supported in KVM. Advertise SME_COHERENT in addition to SEV and SEV-ES, as the guest can use SME_COHERENT to avoid CLFLUSH operations. Explicitly omit SME and VM_PAGE_FLUSH from the reporting. These features are used by KVM, but are not exposed to the guest, e.g. guest access to related MSRs will fault. Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210422021125.3417167-6-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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Ricardo Koller
|
013380782d |
KVM: x86: Move reverse CPUID helpers to separate header file
Split out the reverse CPUID machinery to a dedicated header file so that KVM selftests can reuse the reverse CPUID definitions without introducing any '#ifdef __KERNEL__' pollution. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Ricardo Koller <ricarkol@google.com> Message-Id: <20210422005626.564163-2-ricarkol@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |