Re: [PATCH 03/19] Revert "KVM: SVM: Introduce hybrid-AVIC mode"

From: Sean Christopherson
Date: Thu Sep 01 2022 - 09:33:26 EST


On Thu, Sep 01, 2022, Maxim Levitsky wrote:
> On Wed, 2022-08-31 at 19:12 +0000, Sean Christopherson wrote:
> > On Wed, Aug 31, 2022, Maxim Levitsky wrote:
> > > If you are really hell bent on not having that MMIO exposed, then I say we
> > > can just disable the AVIC memslot, and keep AVIC enabled in this case - this
> > > should make us both happy.
> >
> > I don't think that will work though, as I don't think it's possible to tell hardware
> > not to accelerate AVIC accesses. I.e. KVM can squash the unaccelerated traps, but
> > anything that is handled by hardware will still go through.
>
> Nope! Remember why do we have that APIC private memslot?

Heh, I finally understood what you were suggesting two minutes after I woke up
this morning. Apparently I needed to sleep on it?