Re: [patch 3/3] KVM: move postcommit flush to x86, as mmio sptes are x86 specific

Takuya Yoshikawa
2012-08-28T00:30:45Z

On Mon, 27 Aug 2012 16:06:01 -0300
Marcelo Tosatti <mtosatti@redhat.com> wrote:

> > Any explanation why (old.base_gfn != new.base_gfn) case can be
> > omitted?
>
> (old.base_gfn != new.base_gfn) check covers the cases
>
> 1. old.base_gfn = 0, new.base_gfn = !0 (slot creation)
>
> and
>
> x != 0, y != 0, x != y.
> 2. old.base_gfn = x, new.base_gfn = y (gpa base change)
>
> Patch 2 covers case 2, so its only necessary to cover case
> 1 here.
>
> Makes sense?

Yes.

But didn't you change the flush in the if block modified by patch 2
to kvm_arch_flush_shadow_memslot()?

Although current implementation flushes everything, this may trigger
problem when we change it.

Takuya