KVM: irq ack notification

Based on a patch from: Ben-Ami Yassour <benami@il.ibm.com>
which was based on a patch from: Amit Shah <amit.shah@qumranet.com>

Notify IRQ acking on PIC/APIC emulation. The previous patch missed two things:

- Edge triggered interrupts on IOAPIC
- PIC reset with IRR/ISR set should be equivalent to ack (LAPIC probably
needs something similar).

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
CC: Amit Shah <amit.shah@qumranet.com>
CC: Ben-Ami Yassour <benami@il.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index 9091195..3c508af 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -72,7 +72,7 @@
 		if (kvm_apic_accept_pic_intr(v)) {
 			s = pic_irqchip(v->kvm);
 			s->output = 0;		/* PIC */
-			vector = kvm_pic_read_irq(s);
+			vector = kvm_pic_read_irq(v->kvm);
 		}
 	}
 	return vector;