x86/vpt: only try to resume timers belonging to enabled devices

Check whether the emulated device is actually enabled before trying to
resume the associated timers.

Thankfully all those structures are zeroed at initialization, and
since the devices are not enabled they are never populated, which
triggers the pt->vcpu check at the beginning of pt_resume forcing an
exit from the function.

While there limit the scope of i and make it unsigned.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/arch/x86/hvm/vpt.c b/xen/arch/x86/hvm/vpt.c
index 47f2c2aa646c4ea41305f7a165cd69d695c7790b..62c87867c512743655d1b6fce5a473c63d78553d 100644 (file)
--- a/xen/arch/x86/hvm/vpt.c
+++ b/xen/arch/x86/hvm/vpt.c
@@ -636,14 +636,19 @@ static void pt_resume(struct periodic_time *pt)
 
 void pt_may_unmask_irq(struct domain *d, struct periodic_time *vlapic_pt)
 {
-    int i;
-
     if ( d )
     {
-        pt_resume(&d->arch.vpit.pt0);
-        pt_resume(&d->arch.hvm.pl_time->vrtc.pt);
-        for ( i = 0; i < HPET_TIMER_NUM; i++ )
-            pt_resume(&d->arch.hvm.pl_time->vhpet.pt[i]);
+        if ( has_vpit(d) )
+            pt_resume(&d->arch.vpit.pt0);
+        if ( has_vrtc(d) )
+            pt_resume(&d->arch.hvm.pl_time->vrtc.pt);
+        if ( has_vhpet(d) )
+        {
+            unsigned int i;
+
+            for ( i = 0; i < HPET_TIMER_NUM; i++ )
+                pt_resume(&d->arch.hvm.pl_time->vhpet.pt[i]);
+        }
     }
 
     if ( vlapic_pt )