linux-kernel - Re: [PATCH v5 1/3] KVM: x86: Provide per VM capability for disabling PMU virtualization

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Date:   Wed, 9 Feb 2022 09:30:10 -0800
From:   David Dunn <daviddunn@...gle.com>
To:     Like Xu <like.xu.linux@...il.com>
Cc:     "Paolo Bonzini - Distinguished Engineer (kernel-recipes.org) (KVM HoF)" 
        <pbonzini@...hat.com>, kvm@...r.kernel.org, seanjc@...gle.com,
        Jim Mattson <jmattson@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Joerg Roedel <joro@...tes.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
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 <like.xu.linux@...il.com> 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 <daviddunn@...gle.com> 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 <daviddunn@...gle.com>
> >
> > Nit: The two references to CPUID leaf 0xA should be qualified as
> > applying only to Intel VMs.
> >
> > Reviewed-by: Jim Mattson <jmattson@...gle.com>
> >
>
> Nit: It looks like we already have "#define KVM_CAP_SYS_ATTRIBUTES 209".
>
> Hope it helps a little:
>
> Reviewed-by: Like Xu <likexu@...cent.com>