2022-02-09 11:53:35

by Like Xu

[permalink] [raw]
Subject: Re: [PATCH v5 1/3] KVM: x86: Provide per VM capability for disabling PMU virtualization

cc LKML and full list of KVM reviewers.

On 25/1/2022 2:39 am, Jim Mattson wrote:
> On Sun, Jan 23, 2022 at 10:45 AM David Dunn <[email protected]> wrote:
>>
>> KVM_CAP_PMU_DISABLE is used to disable PMU virtualization on individual
>> x86 VMs. PMU configuration must be done prior to creating VCPUs.
>>
>> To enable future extension, KVM_CAP_PMU_CAPABILITY reports available
>> settings via bitmask when queried via check_extension.
>>
>> For VMs that have PMU virtualization disabled, usermode will need to
>> clear CPUID leaf 0xA to notify guests.
>>
>> Signed-off-by: David Dunn <[email protected]>
>
> Nit: The two references to CPUID leaf 0xA should be qualified as
> applying only to Intel VMs.
>
> Reviewed-by: Jim Mattson <[email protected]>
>

Nit: It looks like we already have "#define KVM_CAP_SYS_ATTRIBUTES 209".

Hope it helps a little:

Reviewed-by: Like Xu <[email protected]>


2022-02-09 18:47:51

by David Dunn

[permalink] [raw]
Subject: Re: [PATCH v5 1/3] KVM: x86: Provide per VM capability for disabling PMU virtualization

Thanks Like.

I just sent a new v6 series with these minor merge conflicts resolved.

Dave

On Wed, Feb 9, 2022 at 2:33 AM Like Xu <[email protected]> wrote:
>
> cc LKML and full list of KVM reviewers.
>
> On 25/1/2022 2:39 am, Jim Mattson wrote:
> > On Sun, Jan 23, 2022 at 10:45 AM David Dunn <[email protected]> wrote:
> >>
> >> KVM_CAP_PMU_DISABLE is used to disable PMU virtualization on individual
> >> x86 VMs. PMU configuration must be done prior to creating VCPUs.
> >>
> >> To enable future extension, KVM_CAP_PMU_CAPABILITY reports available
> >> settings via bitmask when queried via check_extension.
> >>
> >> For VMs that have PMU virtualization disabled, usermode will need to
> >> clear CPUID leaf 0xA to notify guests.
> >>
> >> Signed-off-by: David Dunn <[email protected]>
> >
> > Nit: The two references to CPUID leaf 0xA should be qualified as
> > applying only to Intel VMs.
> >
> > Reviewed-by: Jim Mattson <[email protected]>
> >
>
> Nit: It looks like we already have "#define KVM_CAP_SYS_ATTRIBUTES 209".
>
> Hope it helps a little:
>
> Reviewed-by: Like Xu <[email protected]>