KVM: Grab pic lock in kvm_pic_clear_isr_ack

isr_ack is protected by kvm_pic->lock.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 2520922282d5..bf94a45f4f86 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -72,8 +72,10 @@ static void pic_clear_isr(struct kvm_kpic_state *s, int irq)
 void kvm_pic_clear_isr_ack(struct kvm *kvm)
 {
         struct kvm_pic *s = pic_irqchip(kvm);
+        pic_lock(s);
         s->pics[0].isr_ack = 0xff;
         s->pics[1].isr_ack = 0xff;
+        pic_unlock(s);
 }
 
 /*