--- a/drivers/xen/events/events_2l.c
+++ b/drivers/xen/events/events_2l.c
@@ -76,12 +76,6 @@ static bool evtchn_2l_is_pending(unsigne
 	return sync_test_bit(port, BM(&s->evtchn_pending[0]));
 }
 
-static bool evtchn_2l_test_and_set_mask(unsigned port)
-{
-	struct shared_info *s = HYPERVISOR_shared_info;
-	return sync_test_and_set_bit(port, BM(&s->evtchn_mask[0]));
-}
-
 static void evtchn_2l_mask(unsigned port)
 {
 	struct shared_info *s = HYPERVISOR_shared_info;
@@ -375,7 +369,6 @@ static const struct evtchn_ops evtchn_op
 	.clear_pending     = evtchn_2l_clear_pending,
 	.set_pending       = evtchn_2l_set_pending,
 	.is_pending        = evtchn_2l_is_pending,
-	.test_and_set_mask = evtchn_2l_test_and_set_mask,
 	.mask              = evtchn_2l_mask,
 	.unmask            = evtchn_2l_unmask,
 	.handle_events     = evtchn_2l_handle_events,
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -98,6 +98,7 @@ static DEFINE_RWLOCK(evtchn_rwlock);
  *   evtchn_rwlock
  *     IRQ-desc lock
  *       percpu eoi_list_lock
+ *         irq_info->lock
  */
 
 static LIST_HEAD(xen_irq_list_head);
@@ -219,6 +220,8 @@ static int xen_irq_info_common_setup(str
 	info->irq = irq;
 	info->evtchn = evtchn;
 	info->cpu = cpu;
+	info->mask_reason = EVT_MASK_REASON_EXPLICIT;
+	spin_lock_init(&info->lock);
 
 	ret = set_evtchn_to_irq(evtchn, irq);
 	if (ret < 0)
@@ -366,6 +369,34 @@ unsigned int cpu_from_evtchn(unsigned in
 	return ret;
 }
 
+static void do_mask(struct irq_info *info, u8 reason)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&info->lock, flags);
+
+	if (!info->mask_reason)
+		mask_evtchn(info->evtchn);
+
+	info->mask_reason |= reason;
+
+	spin_unlock_irqrestore(&info->lock, flags);
+}
+
+static void do_unmask(struct irq_info *info, u8 reason)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&info->lock, flags);
+
+	info->mask_reason &= ~reason;
+
+	if (!info->mask_reason)
+		unmask_evtchn(info->evtchn);
+
+	spin_unlock_irqrestore(&info->lock, flags);
+}
+
 #ifdef CONFIG_X86
 static bool pirq_check_eoi_map(unsigned irq)
 {
@@ -493,7 +524,7 @@ static void xen_irq_lateeoi_locked(struc
 	}
 
 	info->eoi_time = 0;
-	unmask_evtchn(evtchn);
+	do_unmask(info, EVT_MASK_REASON_EOI_PENDING);
 }
 
 static void xen_irq_lateeoi_worker(struct work_struct *work)
@@ -680,7 +711,8 @@ static void pirq_query_unmask(int irq)
 
 static void eoi_pirq(struct irq_data *data)
 {
-	int evtchn = evtchn_from_irq(data->irq);
+	struct irq_info *info = info_for_irq(data->irq);
+	int evtchn = info ? info->evtchn : 0;
 	struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
 	int rc = 0;
 
@@ -689,14 +721,13 @@ static void eoi_pirq(struct irq_data *da
 
 	if (unlikely(irqd_is_setaffinity_pending(data)) &&
 	    likely(!irqd_irq_disabled(data))) {
-		int masked = test_and_set_mask(evtchn);
+		do_mask(info, EVT_MASK_REASON_TEMPORARY);
 
 		clear_evtchn(evtchn);
 
 		irq_move_masked_irq(data);
 
-		if (!masked)
-			unmask_evtchn(evtchn);
+		do_unmask(info, EVT_MASK_REASON_TEMPORARY);
 	} else
 		clear_evtchn(evtchn);
 
@@ -749,7 +780,8 @@ static unsigned int __startup_pirq(unsig
 		goto err;
 
 out:
-	unmask_evtchn(evtchn);
+	do_unmask(info, EVT_MASK_REASON_EXPLICIT);
+
 	eoi_pirq(irq_get_irq_data(irq));
 
 	return 0;
@@ -776,7 +808,7 @@ static void shutdown_pirq(struct irq_dat
 	if (!VALID_EVTCHN(evtchn))
 		return;
 
-	mask_evtchn(evtchn);
+	do_mask(info, EVT_MASK_REASON_EXPLICIT);
 	xen_evtchn_close(evtchn);
 	xen_irq_info_cleanup(info);
 }
@@ -1635,10 +1667,10 @@ void rebind_evtchn_irq(int evtchn, int i
 }
 
 /* Rebind an evtchn so that it gets delivered to a specific cpu */
-static int xen_rebind_evtchn_to_cpu(int evtchn, unsigned int tcpu)
+static int xen_rebind_evtchn_to_cpu(struct irq_info *info, unsigned int tcpu)
 {
 	struct evtchn_bind_vcpu bind_vcpu;
-	int masked;
+	evtchn_port_t evtchn = info ? info->evtchn : 0;
 
 	if (!VALID_EVTCHN(evtchn))
 		return -1;
@@ -1654,7 +1686,7 @@ static int xen_rebind_evtchn_to_cpu(int
 	 * Mask the event while changing the VCPU binding to prevent
 	 * it being delivered on an unexpected VCPU.
 	 */
-	masked = test_and_set_mask(evtchn);
+	do_mask(info, EVT_MASK_REASON_TEMPORARY);
 
 	/*
 	 * If this fails, it usually just indicates that we're dealing with a
@@ -1664,8 +1696,7 @@ static int xen_rebind_evtchn_to_cpu(int
 	if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
 		bind_evtchn_to_cpu(evtchn, tcpu);
 
-	if (!masked)
-		unmask_evtchn(evtchn);
+	do_unmask(info, EVT_MASK_REASON_TEMPORARY);
 
 	return 0;
 }
@@ -1674,7 +1705,7 @@ static int set_affinity_irq(struct irq_d
 			    bool force)
 {
 	unsigned tcpu = cpumask_first_and(dest, cpu_online_mask);
-	int ret = xen_rebind_evtchn_to_cpu(evtchn_from_irq(data->irq), tcpu);
+	int ret = xen_rebind_evtchn_to_cpu(info_for_irq(data->irq), tcpu);
 
 	if (!ret)
 		irq_data_update_effective_affinity(data, cpumask_of(tcpu));
@@ -1693,37 +1724,39 @@ EXPORT_SYMBOL_GPL(xen_set_affinity_evtch
 
 static void enable_dynirq(struct irq_data *data)
 {
-	int evtchn = evtchn_from_irq(data->irq);
+	struct irq_info *info = info_for_irq(data->irq);
+	evtchn_port_t evtchn = info ? info->evtchn : 0;
 
 	if (VALID_EVTCHN(evtchn))
-		unmask_evtchn(evtchn);
+		do_unmask(info, EVT_MASK_REASON_EXPLICIT);
 }
 
 static void disable_dynirq(struct irq_data *data)
 {
-	int evtchn = evtchn_from_irq(data->irq);
+	struct irq_info *info = info_for_irq(data->irq);
+	evtchn_port_t evtchn = info ? info->evtchn : 0;
 
 	if (VALID_EVTCHN(evtchn))
-		mask_evtchn(evtchn);
+		do_mask(info, EVT_MASK_REASON_EXPLICIT);
 }
 
 static void ack_dynirq(struct irq_data *data)
 {
-	int evtchn = evtchn_from_irq(data->irq);
+	struct irq_info *info = info_for_irq(data->irq);
+	evtchn_port_t evtchn = info ? info->evtchn : 0;
 
 	if (!VALID_EVTCHN(evtchn))
 		return;
 
 	if (unlikely(irqd_is_setaffinity_pending(data)) &&
 	    likely(!irqd_irq_disabled(data))) {
-		int masked = test_and_set_mask(evtchn);
+		do_mask(info, EVT_MASK_REASON_TEMPORARY);
 
 		clear_evtchn(evtchn);
 
 		irq_move_masked_irq(data);
 
-		if (!masked)
-			unmask_evtchn(evtchn);
+		do_unmask(info, EVT_MASK_REASON_TEMPORARY);
 	} else
 		clear_evtchn(evtchn);
 }
@@ -1734,18 +1767,39 @@ static void mask_ack_dynirq(struct irq_d
 	ack_dynirq(data);
 }
 
+static void lateeoi_ack_dynirq(struct irq_data *data)
+{
+	struct irq_info *info = info_for_irq(data->irq);
+	evtchn_port_t evtchn = info ? info->evtchn : 0;
+
+	if (VALID_EVTCHN(evtchn)) {
+		do_mask(info, EVT_MASK_REASON_EOI_PENDING);
+		clear_evtchn(evtchn);
+	}
+}
+
+static void lateeoi_mask_ack_dynirq(struct irq_data *data)
+{
+	struct irq_info *info = info_for_irq(data->irq);
+	evtchn_port_t evtchn = info ? info->evtchn : 0;
+
+	if (VALID_EVTCHN(evtchn)) {
+		do_mask(info, EVT_MASK_REASON_EXPLICIT);
+		clear_evtchn(evtchn);
+	}
+}
+
 static int retrigger_dynirq(struct irq_data *data)
 {
-	unsigned int evtchn = evtchn_from_irq(data->irq);
-	int masked;
+	struct irq_info *info = info_for_irq(data->irq);
+	evtchn_port_t evtchn = info ? info->evtchn : 0;
 
 	if (!VALID_EVTCHN(evtchn))
 		return 0;
 
-	masked = test_and_set_mask(evtchn);
+	do_mask(info, EVT_MASK_REASON_TEMPORARY);
 	set_evtchn(evtchn);
-	if (!masked)
-		unmask_evtchn(evtchn);
+	do_unmask(info, EVT_MASK_REASON_TEMPORARY);
 
 	return 1;
 }
@@ -1951,8 +2005,8 @@ static struct irq_chip xen_lateeoi_chip
 	.irq_mask		= disable_dynirq,
 	.irq_unmask		= enable_dynirq,
 
-	.irq_ack		= mask_ack_dynirq,
-	.irq_mask_ack		= mask_ack_dynirq,
+	.irq_ack		= lateeoi_ack_dynirq,
+	.irq_mask_ack		= lateeoi_mask_ack_dynirq,
 
 	.irq_set_affinity	= set_affinity_irq,
 	.irq_retrigger		= retrigger_dynirq,
--- a/drivers/xen/events/events_fifo.c
+++ b/drivers/xen/events/events_fifo.c
@@ -209,12 +209,6 @@ static bool evtchn_fifo_is_pending(unsig
 	return sync_test_bit(EVTCHN_FIFO_BIT(PENDING, word), BM(word));
 }
 
-static bool evtchn_fifo_test_and_set_mask(unsigned port)
-{
-	event_word_t *word = event_word_from_port(port);
-	return sync_test_and_set_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word));
-}
-
 static void evtchn_fifo_mask(unsigned port)
 {
 	event_word_t *word = event_word_from_port(port);
@@ -420,7 +414,6 @@ static const struct evtchn_ops evtchn_op
 	.clear_pending     = evtchn_fifo_clear_pending,
 	.set_pending       = evtchn_fifo_set_pending,
 	.is_pending        = evtchn_fifo_is_pending,
-	.test_and_set_mask = evtchn_fifo_test_and_set_mask,
 	.mask              = evtchn_fifo_mask,
 	.unmask            = evtchn_fifo_unmask,
 	.handle_events     = evtchn_fifo_handle_events,
--- a/drivers/xen/events/events_internal.h
+++ b/drivers/xen/events/events_internal.h
@@ -35,13 +35,18 @@ struct irq_info {
 	struct list_head eoi_list;
 	short refcnt;
 	short spurious_cnt;
-	enum xen_irq_type type;	/* type */
+	short type;		/* type */
+	u8 mask_reason;		/* Why is event channel masked */
+#define EVT_MASK_REASON_EXPLICIT	0x01
+#define EVT_MASK_REASON_TEMPORARY	0x02
+#define EVT_MASK_REASON_EOI_PENDING	0x04
 	unsigned irq;
 	unsigned int evtchn;	/* event channel */
 	unsigned short cpu;	/* cpu bound */
 	unsigned short eoi_cpu;	/* EOI must happen on this cpu */
 	unsigned int irq_epoch;	/* If eoi_cpu valid: irq_epoch of event */
 	u64 eoi_time;		/* Time in jiffies when to EOI. */
+	spinlock_t lock;
 
 	union {
 		unsigned short virq;
@@ -73,7 +78,6 @@ struct evtchn_ops {
 	void (*clear_pending)(unsigned port);
 	void (*set_pending)(unsigned port);
 	bool (*is_pending)(unsigned port);
-	bool (*test_and_set_mask)(unsigned port);
 	void (*mask)(unsigned port);
 	void (*unmask)(unsigned port);
 
@@ -138,11 +142,6 @@ static inline bool test_evtchn(unsigned
 	return evtchn_ops->is_pending(port);
 }
 
-static inline bool test_and_set_mask(unsigned port)
-{
-	return evtchn_ops->test_and_set_mask(port);
-}
-
 static inline void mask_evtchn(unsigned port)
 {
 	return evtchn_ops->mask(port);
