Re: [PATCH v2 0/4] implement vcpu preempted check

From: Peter Zijlstra
Date: Thu Jul 07 2016 - 07:21:35 EST


On Thu, Jul 07, 2016 at 11:42:15AM +0200, Peter Zijlstra wrote:
> +static void update_steal_time_preempt(struct kvm_vcpu *vcpu)
> +{
> + struct kvm_steal_time *st;
> +
> + if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
> + return;
> +
> + if (unlikely(kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
> + &vcpu->arch.st.steal, sizeof(struct kvm_steal_time))))
> + return;
> +
> + st = &vcpu->arch.st.steal;
> +
> + st->pad[KVM_ST_PAD_PREEMPT] = 1; /* we've stopped running */

So maybe have this be:

... = kvm_vcpu_running();

That avoids marking the vcpu preempted when we do hlt and such.

> + kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
> + st, sizeof(struct kvm_steal_time));
> +}