diff -r 66df4f35b8de xen/arch/x86/irq.c
--- a/xen/arch/x86/irq.c	Fri Nov 26 10:10:40 2010 +0000
+++ b/xen/arch/x86/irq.c	Mon Nov 29 14:57:40 2010 +0100
@@ -1860,7 +1860,8 @@ int unmap_domain_pirq_emuirq(struct doma
     }
 
     d->arch.pirq_emuirq[pirq] = IRQ_UNBOUND;
-    d->arch.emuirq_pirq[emuirq] = IRQ_UNBOUND;
+    if ( emuirq != IRQ_PT )
+        d->arch.emuirq_pirq[emuirq] = IRQ_UNBOUND;
 
  done:
     return ret;