Re: [PATCH] KVM: x86/mmu: Don't put invalid SPs back on the list of active pages

[Sean Christopherson <sean.j.christopherson@intel.com>]

On Tue, Jun 23, 2020 at 02:23:53AM +0200, Paolo Bonzini wrote:
> On 22/06/20 21:18, Sean Christopherson wrote:
> > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> > index fdd05c233308..fa5bd3f987dd 100644
> > --- a/arch/x86/kvm/mmu/mmu.c
> > +++ b/arch/x86/kvm/mmu/mmu.c
> > @@ -2757,10 +2757,13 @@ static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm,
> >  	if (!sp->root_count) {
> >  		/* Count self */
> >  		(*nr_zapped)++;
> > -		list_move(&sp->link, invalid_list);
> > +		if (sp->role.invalid)
> > +			list_add(&sp->link, invalid_list);
> > +		else
> > +			list_move(&sp->link, invalid_list);
> 
> It's late here, but I think this part needs a comment anyway...

No argument here.  I'll spin a v2, I just realized there is a separate
optimization that can build on this patch.  I was planning on sending it
separately, but I misread the loop in make_mmu_pages_available().