Re: [PATCH v6 4/8] KVM: x86/pmu: Snapshot host IA32_PERF_CAPABILITIES in kvm_host

[Jim Mattson]

On Mon, Jun 29, 2026 at 4:28 PM Zide Chen <zide.chen@xxxxxxxxx> wrote:
>
> From: Mingwei Zhang <mizhang@xxxxxxxxxx>
>
> Cache the unadulterated snapshot of perf_capabilities so that KVM can
> compare guest vPMU capabilities against raw hardware capabilities.
>
> For example, if the host supports PERF_METRICS but it is not configured
> for the guest, KVM can use it to determine that RDPMC accesses must be
> intercepted.
>
> Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx>
> Signed-off-by: Zide Chen <zide.chen@xxxxxxxxx>
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>