Re: [PATCH 1/5] kvm/x86: fix inversed check for async_pf MSR

[Roman Kagan <rkagan@virtuozzo.com>]

On Fri, Dec 02, 2016 at 12:45:28PM +0200, Mika Penttilä wrote:
> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > index bf11fe4..14a46e9 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> > @@ -8402,7 +8402,7 @@ void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
> > bool kvm_arch_can_inject_async_page_present(struct kvm_vcpu *vcpu)
> > {
> > 	if (!(vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED))
> > -		return true;
> > +		return false;
> > 
> > 
> Why do you make this change?

Because the code does the opposite of what it's meant to do.

> I think kvm_arch_async_page_present() is not
> ever called now and neither kvm_del_async_pf_gfn(vcpu, work->arch.gfn);

I wonder how you came to such a conclusion?  I certainly see them called
on my test machine (you need to have the guest memory swapped out for
that, that can be forced e.g. using a memory cgroup).

Roman.