Re: [PATCH v2 3/3] KVM: x86/cpuid: Add AMD CPUID ExtPerfMonAndDbg leaf 0x80000022

[Jim Mattson]

On Mon, Sep 19, 2022 at 2:35 AM Like Xu <like.xu.linux@xxxxxxxxx> wrote:
>
> From: Sandipan Das <sandipan.das@xxxxxxx>
>
> From: Sandipan Das <sandipan.das@xxxxxxx>
>
> CPUID leaf 0x80000022 i.e. ExtPerfMonAndDbg advertises some
> new performance monitoring features for AMD processors.
>
> Bit 0 of EAX indicates support for Performance Monitoring
> Version 2 (PerfMonV2) features. If found to be set during
> PMU initialization, the EBX bits of the same CPUID function
> can be used to determine the number of available PMCs for
> different PMU types.
>
> Expose the relevant bits via KVM_GET_SUPPORTED_CPUID so
> that guests can make use of the PerfMonV2 features.
>
> Co-developed-by: Like Xu <likexu@xxxxxxxxxxx>
> Signed-off-by: Like Xu <likexu@xxxxxxxxxxx>
> Signed-off-by: Sandipan Das <sandipan.das@xxxxxxx>
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>