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-rw-r--r--drivers/xen/events.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 7595581d032c..36bf17dc7bfc 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -373,11 +373,22 @@ static void unmask_evtchn(int port)
{
struct shared_info *s = HYPERVISOR_shared_info;
unsigned int cpu = get_cpu();
+ int do_hypercall = 0, evtchn_pending = 0;
BUG_ON(!irqs_disabled());
- /* Slow path (hypercall) if this is a non-local port. */
- if (unlikely(cpu != cpu_from_evtchn(port))) {
+ if (unlikely((cpu != cpu_from_evtchn(port))))
+ do_hypercall = 1;
+ else
+ evtchn_pending = sync_test_bit(port, &s->evtchn_pending[0]);
+
+ if (unlikely(evtchn_pending && xen_hvm_domain()))
+ do_hypercall = 1;
+
+ /* Slow path (hypercall) if this is a non-local port or if this is
+ * an hvm domain and an event is pending (hvm domains don't have
+ * their own implementation of irq_enable). */
+ if (do_hypercall) {
struct evtchn_unmask unmask = { .port = port };
(void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
} else {
@@ -390,7 +401,7 @@ static void unmask_evtchn(int port)
* 'hw_resend_irq'. Just like a real IO-APIC we 'lose
* the interrupt edge' if the channel is masked.
*/
- if (sync_test_bit(port, &s->evtchn_pending[0]) &&
+ if (evtchn_pending &&
!sync_test_and_set_bit(port / BITS_PER_LONG,
&vcpu_info->evtchn_pending_sel))
vcpu_info->evtchn_upcall_pending = 1;