Re: [PATCH RFC 04/15] KVM: Implement ring-based dirty memory tracking

From: Peter Xu
Date: Tue Dec 17 2019 - 11:42:51 EST


On Tue, Dec 17, 2019 at 05:31:48PM +0100, Paolo Bonzini wrote:
> On 17/12/19 16:38, Peter Xu wrote:
> > There's still time to persuade me to going back to it. :)
> >
> > (Though, yes I still like current solution... if we can get rid of the
> > only kvmgt ugliness, we can even throw away the per-vm ring with its
> > "extra" 4k page. Then I suppose it'll be even harder to persuade me :)
>
> Actually that's what convinced me in the first place, so let's
> absolutely get rid of both the per-VM ring and the union. Kevin and
> Alex have answered and everybody seems to agree.

Yeah that'd be perfect.

However I just noticed something... Note that we still didn't read
into non-x86 archs, I think it's the same question as when I asked
whether we can unify the kvm[_vcpu]_write() interfaces and you'd like
me to read the non-x86 archs - I think it's time I read them, because
it's still possible that non-x86 archs will still need the per-vm
ring... then that could be another problem if we want to at last
spread the dirty ring idea outside of x86.

--
Peter Xu