diff -r b21246720fde xen/arch/x86/hvm/vmx/io.c
--- a/xen/arch/x86/hvm/vmx/io.c	Mon Oct 30 17:35:11 2006 +0000
+++ b/xen/arch/x86/hvm/vmx/io.c	Tue Oct 31 15:18:21 2006 +0800
@@ -120,8 +120,11 @@ asmlinkage void vmx_intr_assist(void)
             pic_set_xen_irq(pic, callback_irq, local_events_need_delivery());
     }
 
-    if ( vlapic && vlapic_enabled(vlapic) && vlapic->flush_tpr_threshold )
-        update_tpr_threshold(vlapic);
+    if ( vlapic && vlapic_enabled(vlapic) ) {
+        vlapic_update_ppr(vlapic);
+        if ( vlapic->flush_tpr_threshold )
+            update_tpr_threshold(vlapic);
+    }
 
     has_ext_irq = cpu_has_pending_irq(v);