Re: [PATCH] x86: kvm: Avoid guest page table walk when gpa_available is set

[Brijesh Singh]

Hi Paolo,

> > I've tried the below patch and it seems to work fine. This does not
> > consider
> > PIO case and as you rightly pointed PIO should trigger #NPF relatively
> > rarely.
> > At least so far in my runs I have not seen PIO causing #NPF. If this sounds
> > acceptable approach then I can submit v2 with these changes and remove
> > gpa_val
> > additional.
>
> PIO can certainly cause #NPF, albeit rarely, so this is not a viable one.

For SEV guest cases, we anyway want to avoid any guest page table walks
(even if it happens rarely). Sounds like we have to depend on gpa_val variable.
I will refresh the patch to address one of Ramdim's feedback
(move vcpu->arch.gpa_val assignment from handle_exit to pf_interception).

Brijesh