On Wed, 30 Mar 2022 at 08:07, Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
>
> On Fri, Mar 25, 2022, Wanpeng Li wrote:
> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > index 425fd7f38fa9..6b300496bbd0 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> > @@ -10375,6 +10375,28 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
> > return r;
> > }
> >
> > +static int kvm_vcpu_non_preemptable(struct kvm_vcpu *vcpu)
>
> s/preemtable/preemptible
>
> And I'd recommend inverting the return, and also return a bool, i.e.
>
> static bool kvm_vcpu_is_preemptible(struct kvm_vcpu *vcpu)
Good suggestion.
>
> > +{
> > + int count;
> > +
> > + if (!vcpu->arch.pv_pc.preempt_count_enabled)
> > + return 0;
> > +
> > + if (!kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_pc.preempt_count_cache,
> > + &count, sizeof(int)))
> > + return (count & ~PREEMPT_NEED_RESCHED);
>
> This cements PREEMPT_NEED_RESCHED into KVM's guest/host ABI. I doubt the sched
> folks will be happy with that.
>
> > +
> > + return 0;
> > +}
> > +
