From 5e0018b3e39e9b44dbfb380b83026e55d2f65b91 Mon Sep 17 00:00:00 2001
From: Davidlohr Bueso <dave@stgolabs.net>
Date: Wed, 13 Sep 2017 13:08:22 -0700
Subject: [PATCH] kvm: Serialize wq active checks in kvm_vcpu_wake_up()
Git-commit: 5e0018b3e39e9b44dbfb380b83026e55d2f65b91
Patch-mainline: v4.14-rc1
References: bsc#1060747
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>
---
virt/kvm/kvm_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2d7df5cc955b..9deb5a245b83 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -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;
--
2.12.0