Re: [PATCH v2] KVM: SVM: emulate MSR_IA32_PERF_CAPABILITIES

[Paolo Bonzini]

On 18/06/20 13:13, Vitaly Kuznetsov wrote:
> state_test/smm_test selftests are failing on AMD with:
> "Unexpected result from KVM_GET_MSRS, r: 51 (failed MSR was 0x345)"
> 
> MSR_IA32_PERF_CAPABILITIES is an emulated MSR on Intel but it is not
> known to AMD code, emulate it there too (by returning 0 and allowing
> userspace to write 0). This way the code is better prepared to the
> eventual appearance of the feature in AMD hardware.
> 
> Fixes: 27461da31089 ("KVM: x86/pmu: Support full width counting")
> Suggested-by: Jim Mattson <jmattson@xxxxxxxxxx>
> Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> ---
>  arch/x86/kvm/svm/pmu.c | 29 ++++++++++++++++++++++++++++-
>  1 file changed, 28 insertions(+), 1 deletion(-)

This is okay and I'll apply it, but it would be even better to move the
whole handling of the MSR to common x86 code.

Paolo