Commit 5e0018b3 authored Sep 13, 2017 by Davidlohr Bueso Committed by Paolo Bonzini Sep 15, 2017

kvm: Serialize wq active checks in kvm_vcpu_wake_up()



This is a generic call and can be suceptible to races
in reading the wq task_list while another task is adding
itself to the list. Add a full barrier by using the
swq_has_sleeper() helper.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent a0cff57b

virt/kvm/kvm_main.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2187,7 +2187,7 @@ bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu)
		struct swait_queue_head *wqp;

		wqp = kvm_arch_vcpu_wq(vcpu);
		if (swait_active(wqp)) {
		if (swq_has_sleeper(wqp)) {
		swake_up(wqp);
		++vcpu->stat.halt_wakeup;
		return true;