Signed-off-by Beth Kon <address@hidden>

diff --git a/hw/apic.c b/hw/apic.c
index a2915f8..3e34132 100644
--- a/hw/apic.c
+++ b/hw/apic.c
@@ -945,6 +945,13 @@ void ioapic_set_irq(void *opaque, int vector, int level)
 {
     IOAPICState *s = opaque;
 
+    /* ISA IRQs map to GSI 1-1 except for IRQ0 which maps
+       to GSI 2.  GSI maps to ioapic 1-1.  This is not
+       the cleanest way of doing it but it should work. */
+
+    if (vector == 0)
+        vector = 2;
+
     if (vector >= 0 && vector < IOAPIC_NUM_PINS) {
         uint32_t mask = 1 << vector;
         uint64_t entry = s->ioredtbl[vector];