KVM: read apic->irr with ioapic lock held

Commit Message

Marcelo Tosatti June 2, 2010, 2:26 p.m. UTC

None

Patch

diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index 3bc4fdb..1149c60 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -193,12 +193,13 @@  static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
 
 int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level)
 {
-	u32 old_irr = ioapic->irr;
+	u32 old_irr;
 	u32 mask = 1 << irq;
 	union kvm_ioapic_redirect_entry entry;
 	int ret = 1;
 
 	spin_lock(&ioapic->lock);
+	old_irr = ioapic->irr;
 	if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
 		entry = ioapic->redirtbl[irq];
 		level ^= entry.fields.polarity;