Re: [PATCH v3 4/4] KVM: Add flush_on_enter before guest enter

[Peter Zijlstra]

On Fri, Nov 10, 2017 at 01:49:47AM -0800, Wanpeng Li wrote:
> @@ -2887,7 +2899,7 @@ static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu)
>  	if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
>  		return;
>  
> -	vcpu->arch.st.steal.preempted = KVM_VCPU_PREEMPTED;
> +	vcpu->arch.st.steal.preempted |= KVM_VCPU_PREEMPTED;

I don't understand this one... If there is concurrency its wrong, if
there is no concurrency it still doesn't make sense as there should not
be any FLUSH flags to preserve..

>  
>  	kvm_write_guest_offset_cached(vcpu->kvm, &vcpu->arch.st.stime,
>  			&vcpu->arch.st.steal.preempted,