diff --git a/xen/arch/x86/hpet.c b/xen/arch/x86/hpet.c
index 46f4c428a1..8229c635e4 100644
--- a/xen/arch/x86/hpet.c
+++ b/xen/arch/x86/hpet.c
@@ -189,12 +189,11 @@ again:
     {
         s_time_t deadline;
 
-        rmb();
-        deadline = per_cpu(timer_deadline, cpu);
-        rmb();
         if ( !cpumask_test_cpu(cpu, ch->cpumask) )
             continue;
 
+        deadline = ACCESS_ONCE(per_cpu(timer_deadline, cpu));
+
         if ( deadline <= now )
             __cpumask_set_cpu(cpu, &mask);
         else if ( deadline < next_event )
@@ -697,8 +696,9 @@ void hpet_broadcast_enter(void)
 {
     unsigned int cpu = smp_processor_id();
     struct hpet_event_channel *ch = per_cpu(cpu_bc_channel, cpu);
+    s_time_t deadline = per_cpu(timer_deadline, cpu);
 
-    if ( per_cpu(timer_deadline, cpu) == 0 )
+    if ( deadline == 0 )
         return;
 
     if ( !ch )
@@ -714,9 +714,12 @@ void hpet_broadcast_enter(void)
     cpumask_set_cpu(cpu, ch->cpumask);
 
     spin_lock(&ch->lock);
-    /* reprogram if current cpu expire time is nearer */
-    if ( per_cpu(timer_deadline, cpu) < ch->next_event )
-        reprogram_hpet_evt_channel(ch, per_cpu(timer_deadline, cpu), NOW(), 1);
+    /*
+     * Reprogram if current cpu expire time is nearer.  deadline is never
+     * written by a remote cpu, so the value read earlier is still valid.
+     */
+    if ( deadline < ch->next_event )
+        reprogram_hpet_evt_channel(ch, deadline, NOW(), 1);
     spin_unlock(&ch->lock);
 }
 
@@ -724,8 +727,9 @@ void hpet_broadcast_exit(void)
 {
     unsigned int cpu = smp_processor_id();
     struct hpet_event_channel *ch = per_cpu(cpu_bc_channel, cpu);
+    s_time_t deadline = per_cpu(timer_deadline, cpu);
 
-    if ( per_cpu(timer_deadline, cpu) == 0 )
+    if ( deadline == 0 )
         return;
 
     if ( !ch )
@@ -733,7 +737,7 @@ void hpet_broadcast_exit(void)
 
     /* Reprogram the deadline; trigger timer work now if it has passed. */
     enable_APIC_timer();
-    if ( !reprogram_timer(per_cpu(timer_deadline, cpu)) )
+    if ( !reprogram_timer(deadline) )
         raise_softirq(TIMER_SOFTIRQ);
 
     cpumask_clear_cpu(cpu, ch->cpumask);