diff -r cfdbdca5b831 xen/arch/x86/hvm/vpt.c
--- a/xen/arch/x86/hvm/vpt.c	Thu Dec 06 15:36:07 2007 +0000
+++ b/xen/arch/x86/hvm/vpt.c	Fri Jan 04 17:58:16 2008 -0500
@@ -58,7 +58,7 @@ static void pt_process_missed_ticks(stru
 
     missed_ticks = missed_ticks / (s_time_t) pt->period + 1;
     if ( mode_is(pt->vcpu->domain, no_missed_ticks_pending) )
-        pt->do_not_freeze = !pt->pending_intr_nr;
+        pt->do_not_freeze = 1;
     else
         pt->pending_intr_nr += missed_ticks;
     pt->scheduled += missed_ticks * pt->period;
@@ -127,7 +127,12 @@ static void pt_timer_fn(void *data)
 
     pt_lock(pt);
 
-    pt->pending_intr_nr++;
+    if ( mode_is(pt->vcpu->domain, no_missed_ticks_pending) ) {
+        pt->pending_intr_nr = 1;
+	pt->do_not_freeze = 0;
+    }
+    else
+	pt->pending_intr_nr++;
 
     if ( !pt->one_shot )
     {
@@ -221,8 +226,6 @@ void pt_intr_post(struct vcpu *v, struct
         return;
     }
 
-    pt->do_not_freeze = 0;
-
     if ( pt->one_shot )
     {
         pt->enabled = 0;
@@ -235,6 +238,10 @@ void pt_intr_post(struct vcpu *v, struct
             pt->last_plt_gtime = hvm_get_guest_time(v);
             pt->pending_intr_nr = 0; /* 'collapse' all missed ticks */
         }
+	else if ( mode_is(v->domain, no_missed_ticks_pending) ) {
+	    pt->pending_intr_nr--;
+	    pt->last_plt_gtime = hvm_get_guest_time(v);
+	}
         else
         {
             pt->last_plt_gtime += pt->period_cycles;