On 1/8/2026 11:53 PM, Dongli Zhang wrote:
> Although AMD PERFCORE and PerfMonV2 are removed when "-pmu" is configured,
> there is no way to fully disable KVM AMD PMU virtualization. Neither
> "-cpu host,-pmu" nor "-cpu EPYC" achieves this.
>
> As a result, the following message still appears in the VM dmesg:
>
> [ 0.263615] Performance Events: AMD PMU driver.
>
> However, the expected output should be:
>
> [ 0.596381] Performance Events: PMU not available due to virtualization,
> using software events only.
> [ 0.600972] NMI watchdog: Perf NMI watchdog permanently disabled
>
> This occurs because AMD does not use any CPUID bit to indicate PMU
> availability.
>
> To address this, KVM_CAP_PMU_CAPABILITY is used to set KVM_PMU_CAP_DISABLE
> when "-pmu" is configured.
>
> Signed-off-by: Dongli Zhang <[email protected]>
> Reviewed-by: Xiaoyao Li <[email protected]>
> Reviewed-by: Zhao Liu <[email protected]>
> Reviewed-by: Dapeng Mi <[email protected]>
> ---
LGTM.
Reviewed-by: Zide Chen <[email protected]>
