From cc1b46803a671047be22f7832ef4a2bb3f63dd94 Mon Sep 17 00:00:00 2001
From: Davidlohr Bueso <dave@stgolabs.net>
Date: Wed, 13 Sep 2017 13:08:20 -0700
Subject: [PATCH] kvm,lapic: Justify use of swait_active()
Git-commit: cc1b46803a671047be22f7832ef4a2bb3f63dd94
Patch-mainline: v4.14-rc1
References: bsc#1060747
A comment might serve future readers.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/lapic.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index aaf10b6f5380..69c5612be786 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1324,6 +1324,10 @@ static void apic_timer_expired(struct kvm_lapic *apic)
atomic_inc(&apic->lapic_timer.pending);
kvm_set_pending_timer(vcpu);
+ /*
+ * For x86, the atomic_inc() is serialized, thus
+ * using swait_active() is safe.
+ */
if (swait_active(q))
swake_up(q);
--
2.12.0