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| author | Paolo Bonzini <pbonzini@redhat.com> | 2024-11-13 12:39:45 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2024-11-13 20:40:56 +0100 |
| commit | b467ab82a9fde4b46c0cd2c299220857afb0e0d4 (patch) | |
| tree | d6aeaa7de1367983f667668ba5cb8aad21163094 /arch/x86/kvm | |
| parent | x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest (diff) | |
| download | linux-b467ab82a9fde4b46c0cd2c299220857afb0e0d4.tar.xz linux-b467ab82a9fde4b46c0cd2c299220857afb0e0d4.zip | |
KVM: x86: expose MSR_PLATFORM_INFO as a feature MSR
For userspace that wants to disable KVM_X86_QUIRK_STUFF_FEATURE_MSRS, it
is useful to know what bits can be set to 1 in MSR_PLATFORM_INFO (apart
from the TSC ratio). The right way to do that is via /dev/kvm's
feature MSR mechanism.
In fact, MSR_PLATFORM_INFO is already a feature MSR for the purpose of
blocking updates after the vCPU is run, but KVM_GET_MSRS did not return
a valid value for it.
Just like in a VM that leaves KVM_X86_QUIRK_STUFF_FEATURE_MSRS enabled,
the TSC ratio field is left to 0. Only bit 31 is set.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/x86.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8637bc001096..2e713480933a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1675,6 +1675,9 @@ static int kvm_get_feature_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data, case MSR_IA32_PERF_CAPABILITIES: *data = kvm_caps.supported_perf_cap; break; + case MSR_PLATFORM_INFO: + *data = MSR_PLATFORM_INFO_CPUID_FAULT; + break; case MSR_IA32_UCODE_REV: rdmsrl_safe(index, data); break; |