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References: <20220919093453.71737-1-likexu@tencent.com> <20220919093453.71737-4-likexu@tencent.com>
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From:   Jim Mattson <jmattson@google.com>
Date:   Tue, 20 Sep 2022 17:02:46 -0700
Message-ID: <CALMp9eTXRmuBvNNMhPvcwZE3+kFzR8qJYNspB2jjBoaw_EjS2A@mail.gmail.com>
Subject: Re: [PATCH v2 3/3] KVM: x86/cpuid: Add AMD CPUID ExtPerfMonAndDbg
 leaf 0x80000022
To:     Like Xu <like.xu.linux@gmail.com>
Cc:     Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, Sandipan Das <sandipan.das@amd.com>
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On Mon, Sep 19, 2022 at 2:35 AM Like Xu <like.xu.linux@gmail.com> wrote:
>
> From: Sandipan Das <sandipan.das@amd.com>
>
> From: Sandipan Das <sandipan.das@amd.com>
>
> 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@tencent.com>
> Signed-off-by: Like Xu <likexu@tencent.com>
> Signed-off-by: Sandipan Das <sandipan.das@amd.com>
Reviewed-by: Jim Mattson <jmattson@google.com>