Re: [PATCH 1/4] KVM: x86: Disable intercept for CORE cstate read

[Wanpeng Li]

On Mon, 20 May 2019 at 18:30, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
>
> On 17/05/19 10:49, Wanpeng Li wrote:
> > From: Wanpeng Li <wanpengli@xxxxxxxxxxx>
> >
> > Allow guest reads CORE cstate when exposing host CPU power management capabilities
> > to the guest. PKG cstate is restricted to avoid a guest to get the whole package
> > information in multi-tenant scenario.
>
> Hmm, I am not sure about this.  I can see why it can be useful to run
> turbostat in the guest, but is it a good idea to share it with the

Yeah.

> guest, since it counts from machine reset rather than from VM reset?

I also saw amazon expose these in their nitro c5 instance.

>
> Maybe it could use a separate bit for KVM_CAP_X86_DISABLE_EXITS?

It could be.

Regards,
Wanpeng Li