| 1a14928e | 28-Jul-2025 |
Paolo Bonzini <pbonzini@redhat.com> |
Merge tag 'kvm-x86-misc-6.17' of https://github.com/kvm-x86/linux into HEAD
KVM x86 misc changes for 6.17
- Prevert the host's DEBUGCTL.FREEZE_IN_SMM (Intel only) when running the
guest. Failu
Merge tag 'kvm-x86-misc-6.17' of https://github.com/kvm-x86/linux into HEAD
KVM x86 misc changes for 6.17
- Prevert the host's DEBUGCTL.FREEZE_IN_SMM (Intel only) when running the
guest. Failure to honor FREEZE_IN_SMM can bleed host state into the guest.
- Explicitly check vmcs12.GUEST_DEBUGCTL on nested VM-Enter (Intel only) to
prevent L1 from running L2 with features that KVM doesn't support, e.g. BTF.
- Intercept SPEC_CTRL on AMD if the MSR shouldn't exist according to the
vCPU's CPUID model.
- Rework the MSR interception code so that the SVM and VMX APIs are more or
less identical.
- Recalculate all MSR intercepts from the "source" on MSR filter changes, and
drop the dedicated "shadow" bitmaps (and their awful "max" size defines).
- WARN and reject loading kvm-amd.ko instead of panicking the kernel if the
nested SVM MSRPM offsets tracker can't handle an MSR.
- Advertise support for LKGS (Load Kernel GS base), a new instruction that's
loosely related to FRED, but is supported and enumerated independently.
- Fix a user-triggerable WARN that syzkaller found by stuffing INIT_RECEIVED,
a.k.a. WFS, and then putting the vCPU into VMX Root Mode (post-VMXON). Use
the same approach KVM uses for dealing with "impossible" emulation when
running a !URG guest, and simply wait until KVM_RUN to detect that the vCPU
has architecturally impossible state.
- Add KVM_X86_DISABLE_EXITS_APERFMPERF to allow disabling interception of
APERF/MPERF reads, so that a "properly" configured VM can "virtualize"
APERF/MPERF (with many caveats).
- Reject KVM_SET_TSC_KHZ if vCPUs have been created, as changing the "default"
frequency is unsupported for VMs with a "secure" TSC, and there's no known
use case for changing the default frequency for other VM types.
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| 5e9ac644 | 06-May-2025 |
Sean Christopherson <seanjc@google.com> |
KVM: selftests: Add a test for x86's fastops emulation
Add a test to verify KVM's fastops emulation via forced emulation. KVM's
so called "fastop" infrastructure executes the to-be-emulated instruc
KVM: selftests: Add a test for x86's fastops emulation
Add a test to verify KVM's fastops emulation via forced emulation. KVM's
so called "fastop" infrastructure executes the to-be-emulated instruction
directly on hardware instead of manually emulating the instruction in
software, using various shenanigans to glue together the emulator context
and CPU state, e.g. to get RFLAGS fed into the instruction and back out
for the emulator.
Add testcases for all instructions that are low hanging fruit. While the
primary goal of the selftest is to validate the glue code, a secondary
goal is to ensure "emulation" matches hardware exactly, including for
arithmetic flags that are architecturally undefined. While arithmetic
flags may be *architecturally* undefined, their behavior is deterministic
for a given CPU (likely a given uarch, and possibly even an entire family
or class of CPUs). I.e. KVM has effectively been emulating underlying
hardware behavior for years.
Link: https://lore.kernel.org/r/20250506011250.1089254-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| ada014f5 | 06-Mar-2025 |
Pratik R. Sampat <prsampat@amd.com> |
KVM: selftests: Add a basic SEV-SNP smoke test
Extend sev_smoke_test to also run a minimal SEV-SNP smoke test that
initializes and sets up private memory regions required to run a simple
SEV-SNP gue
KVM: selftests: Add a basic SEV-SNP smoke test
Extend sev_smoke_test to also run a minimal SEV-SNP smoke test that
initializes and sets up private memory regions required to run a simple
SEV-SNP guest.
Similar to its SEV-ES smoke test counterpart, this also does not
support GHCB and ucall yet and uses the GHCB MSR protocol to trigger an
exit of the type KVM_EXIT_SYSTEM_EVENT.
Signed-off-by: Pratik R. Sampat <prsampat@amd.com>
Link: https://lore.kernel.org/r/20250305230000.231025-11-prsampat@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| a5d55f78 | 05-Mar-2025 |
Pratik R. Sampat <prsampat@amd.com> |
KVM: selftests: Decouple SEV policy from VM type
In preparation for SNP, cleanup the smoke test to decouple deriving type
from policy. This will allow reusing the existing interfaces for SNP.
No f
KVM: selftests: Decouple SEV policy from VM type
In preparation for SNP, cleanup the smoke test to decouple deriving type
from policy. This will allow reusing the existing interfaces for SNP.
No functional change intended.
Signed-off-by: Pratik R. Sampat <prsampat@amd.com>
Link: https://lore.kernel.org/r/20250305230000.231025-10-prsampat@amd.com
[sean: massage shortlog+changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| 4a4e1e8e | 05-Mar-2025 |
Pratik R. Sampat <prsampat@amd.com> |
KVM: selftests: Introduce SEV VM type check
In preparation for SNP, declutter the vm type check by introducing a
SEV-SNP VM type check as well as a transitive set of helper functions.
The SNP VM ty
KVM: selftests: Introduce SEV VM type check
In preparation for SNP, declutter the vm type check by introducing a
SEV-SNP VM type check as well as a transitive set of helper functions.
The SNP VM type is the subset of SEV-ES. Similarly, the SEV-ES and SNP
types are subset of the SEV VM type check.
Signed-off-by: Pratik R. Sampat <prsampat@amd.com>
Link: https://lore.kernel.org/r/20250305230000.231025-7-prsampat@amd.com
[sean: make the helpers static inlines]
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| acf06434 | 05-Mar-2025 |
Pratik R. Sampat <prsampat@amd.com> |
KVM: selftests: Add SMT control state helper
Move the SMT control check out of the hyperv_cpuid selftest so that it
is generally accessible all KVM selftests. Split the functionality into
a helper t
KVM: selftests: Add SMT control state helper
Move the SMT control check out of the hyperv_cpuid selftest so that it
is generally accessible all KVM selftests. Split the functionality into
a helper that populates a buffer with SMT control value which other
helpers can use to ascertain if SMT state is available and active.
Signed-off-by: Pratik R. Sampat <prsampat@amd.com>
Link: https://lore.kernel.org/r/20250305230000.231025-5-prsampat@amd.com
[sean: prepend is_ to the helpers]
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| c4e1a848 | 05-Mar-2025 |
Pratik R. Sampat <prsampat@amd.com> |
KVM: selftests: Add vmgexit helper
Abstract rep vmmcall coded into the vmgexit helper for the sev
library.
No functional change intended.
Signed-off-by: Pratik R. Sampat <prsampat@amd.com>
Reviewe
KVM: selftests: Add vmgexit helper
Abstract rep vmmcall coded into the vmgexit helper for the sev
library.
No functional change intended.
Signed-off-by: Pratik R. Sampat <prsampat@amd.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Link: https://lore.kernel.org/r/20250305230000.231025-4-prsampat@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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| 783e9cd0 | 19-Mar-2025 |
Paolo Bonzini <pbonzini@redhat.com> |
Merge tag 'kvm-x86-selftests-6.15' of https://github.com/kvm-x86/linux into HEAD
KVM selftests changes for 6.15, part 2
- Fix a variety of flaws, bugs, and false failures/passes dirty_log_test, an
Merge tag 'kvm-x86-selftests-6.15' of https://github.com/kvm-x86/linux into HEAD
KVM selftests changes for 6.15, part 2
- Fix a variety of flaws, bugs, and false failures/passes dirty_log_test, and
improve its coverage by collecting all dirty entries on each iteration.
- Fix a few minor bugs related to handling of stats FDs.
- Add infrastructure to make vCPU and VM stats FDs available to tests by
default (open the FDs during VM/vCPU creation).
- Relax an assertion on the number of HLT exits in the xAPIC IPI test when
running on a CPU that supports AMD's Idle HLT (which elides interception of
HLT if a virtual IRQ is pending and unmasked).
- Misc cleanups and fixes.
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| 9b47f288 | 19-Mar-2025 |
Paolo Bonzini <pbonzini@redhat.com> |
Merge tag 'kvm-x86-selftests_6.15-1' of https://github.com/kvm-x86/linux into HEAD
KVM selftests changes for 6.15, part 1
- Misc cleanups and prep work.
- Annotate _no_printf() with "printf" so
Merge tag 'kvm-x86-selftests_6.15-1' of https://github.com/kvm-x86/linux into HEAD
KVM selftests changes for 6.15, part 1
- Misc cleanups and prep work.
- Annotate _no_printf() with "printf" so that pr_debug() statements are
checked by the compiler for default builds (and pr_info() when QUIET).
- 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. The theory is 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 an event is
counting correctly without actually knowing what the event counts on the
underlying hardware.
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| 62838fa5 | 27-Feb-2025 |
Sean Christopherson <seanjc@google.com> |
KVM: selftests: Relax assertion on HLT exits if CPU supports Idle HLT
If the CPU supports Idle HLT, which elides HLT VM-Exits if the vCPU has an
unmasked pending IRQ or NMI, relax the xAPIC IPI test
KVM: selftests: Relax assertion on HLT exits if CPU supports Idle HLT
If the CPU supports Idle HLT, which elides HLT VM-Exits if the vCPU has an
unmasked pending IRQ or NMI, relax the xAPIC IPI test's assertion on the
number of HLT exits to only require that the number of exits is less than
or equal to the number of HLT instructions that were executed. I.e. don't
fail the test if Idle HLT does what it's supposed to do.
Note, unfortunately there's no way to determine if *KVM* supports Idle HLT,
as this_cpu_has() checks raw CPU support, and kvm_cpu_has() checks what can
be exposed to L1, i.e. the latter would check if KVM supports nested Idle
HLT. But, since the assert is purely bonus coverage, checking for CPU
support is good enough.
Cc: Manali Shukla <Manali.Shukla@amd.com>
Tested-by: Manali Shukla <Manali.Shukla@amd.com>
Link: https://lore.kernel.org/r/20250226231809.3183093-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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