Merge remote-tracking branch 'xen-two/linux-next'

9 files changed, 1005 insertions, 366 deletions

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index d7aa39e349a6..cc4514c9d8a6 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -281,7 +281,7 @@ static int blkif_queue_request(struct request *req)
 	info->shadow[id].request = req;
 
 	ring_req->id = id;
-	ring_req->sector_number = (blkif_sector_t)blk_rq_pos(req);
+	ring_req->u.rw.sector_number = (blkif_sector_t)blk_rq_pos(req);
 	ring_req->handle = info->handle;
 
 	ring_req->operation = rq_data_dir(req) ?
@@ -317,7 +317,7 @@ static int blkif_queue_request(struct request *req)
 				rq_data_dir(req) );
 
 		info->shadow[id].frame[i] = mfn_to_pfn(buffer_mfn);
-		ring_req->seg[i] =
+		ring_req->u.rw.seg[i] =
 				(struct blkif_request_segment) {
 					.gref       = ref,
 					.first_sect = fsect,
@@ -615,7 +615,7 @@ static void blkif_completion(struct blk_shadow *s)
 {
 	int i;
 	for (i = 0; i < s->req.nr_segments; i++)
-		gnttab_end_foreign_access(s->req.seg[i].gref, 0, 0UL);
+		gnttab_end_foreign_access(s->req.u.rw.seg[i].gref, 0, 0UL);
 }
 
 static irqreturn_t blkif_interrupt(int irq, void *dev_id)
@@ -932,7 +932,7 @@ static int blkif_recover(struct blkfront_info *info)
 		/* Rewrite any grant references invalidated by susp/resume. */
 		for (j = 0; j < req->nr_segments; j++)
 			gnttab_grant_foreign_access_ref(
-				req->seg[j].gref,
+				req->u.rw.seg[j].gref,
 				info->xbdev->otherend_id,
 				pfn_to_mfn(info->shadow[req->id].frame[j]),
 				rq_data_dir(info->shadow[req->id].request));
diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
index 3a5a6fcc0ead..492b7d807fe8 100644
--- a/drivers/pci/xen-pcifront.c
+++ b/drivers/pci/xen-pcifront.c
@@ -243,7 +243,7 @@ struct pci_ops pcifront_bus_ops = {
 
 #ifdef CONFIG_PCI_MSI
 static int pci_frontend_enable_msix(struct pci_dev *dev,
-				    int **vector, int nvec)
+				    int vector[], int nvec)
 {
 	int err;
 	int i;
@@ -277,18 +277,24 @@ static int pci_frontend_enable_msix(struct pci_dev *dev,
 	if (likely(!err)) {
 		if (likely(!op.value)) {
 			/* we get the result */
-			for (i = 0; i < nvec; i++)
-				*(*vector+i) = op.msix_entries[i].vector;
-			return 0;
+			for (i = 0; i < nvec; i++) {
+				if (op.msix_entries[i].vector <= 0) {
+					dev_warn(&dev->dev, "MSI-X entry %d is invalid: %d!\n",
+						i, op.msix_entries[i].vector);
+					err = -EINVAL;
+					vector[i] = -1;
+					continue;
+				}
+				vector[i] = op.msix_entries[i].vector;
+			}
 		} else {
 			printk(KERN_DEBUG "enable msix get value %x\n",
 				op.value);
-			return op.value;
 		}
 	} else {
 		dev_err(&dev->dev, "enable msix get err %x\n", err);
-		return err;
 	}
+	return err;
 }
 
 static void pci_frontend_disable_msix(struct pci_dev *dev)
@@ -310,7 +316,7 @@ static void pci_frontend_disable_msix(struct pci_dev *dev)
 		dev_err(&dev->dev, "pci_disable_msix get err %x\n", err);
 }
 
-static int pci_frontend_enable_msi(struct pci_dev *dev, int **vector)
+static int pci_frontend_enable_msi(struct pci_dev *dev, int vector[])
 {
 	int err;
 	struct xen_pci_op op = {
@@ -324,7 +330,13 @@ static int pci_frontend_enable_msi(struct pci_dev *dev, int **vector)
 
 	err = do_pci_op(pdev, &op);
 	if (likely(!err)) {
-		*(*vector) = op.value;
+		vector[0] = op.value;
+		if (op.value <= 0) {
+			dev_warn(&dev->dev, "MSI entry is invalid: %d!\n",
+				op.value);
+			err = -EINVAL;
+			vector[0] = -1;
+		}
 	} else {
 		dev_err(&dev->dev, "pci frontend enable msi failed for dev "
 				    "%x:%x\n", op.bus, op.devfn);
@@ -733,8 +745,7 @@ static void free_pdev(struct pcifront_device *pdev)
 
 	pcifront_free_roots(pdev);
 
-	/*For PCIE_AER error handling job*/
-	flush_scheduled_work();
+	cancel_work_sync(&pdev->op_work);
 
 	if (pdev->irq >= 0)
 		unbind_from_irqhandler(pdev->irq, pdev);
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 07bec09d1dad..a59638b37c1a 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -76,10 +76,20 @@ config XEN_XENBUS_FRONTEND
 config XEN_GNTDEV
 	tristate "userspace grant access device driver"
 	depends on XEN
+	default m
 	select MMU_NOTIFIER
 	help
 	  Allows userspace processes to use grants.
 
+config XEN_GRANT_DEV_ALLOC
+	tristate "User-space grant reference allocator driver"
+	depends on XEN
+	default m
+	help
+	  Allows userspace processes to create pages with access granted
+	  to other domains. This can be used to implement frontend drivers
+	  or as part of an inter-domain shared memory channel.
+
 config XEN_PLATFORM_PCI
 	tristate "xen platform pci device driver"
 	depends on XEN_PVHVM && PCI
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 5088cc2e6fe2..9585a1da52c6 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_XEN_XENCOMM)	+= xencomm.o
 obj-$(CONFIG_XEN_BALLOON)	+= balloon.o
 obj-$(CONFIG_XEN_DEV_EVTCHN)	+= xen-evtchn.o
 obj-$(CONFIG_XEN_GNTDEV)	+= xen-gntdev.o
+obj-$(CONFIG_XEN_GRANT_DEV_ALLOC)	+= xen-gntalloc.o
 obj-$(CONFIG_XENFS)		+= xenfs/
 obj-$(CONFIG_XEN_SYS_HYPERVISOR)	+= sys-hypervisor.o
 obj-$(CONFIG_XEN_PLATFORM_PCI)	+= xen-platform-pci.o
@@ -18,5 +19,6 @@ obj-$(CONFIG_XEN_DOM0)		+= pci.o
 
 xen-evtchn-y			:= evtchn.o
 xen-gntdev-y				:= gntdev.o
+xen-gntalloc-y				:= gntalloc.o
 
 xen-platform-pci-y		:= platform-pci.o
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 43f9f02c7db0..b1661cd416b0 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -296,7 +296,7 @@ static int decrease_reservation(unsigned long nr_pages)
 	/* No more mappings: invalidate P2M and add to balloon. */
 	for (i = 0; i < nr_pages; i++) {
 		pfn = mfn_to_pfn(frame_list[i]);
-		set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
+		__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
 		balloon_append(pfn_to_page(pfn));
 	}
 
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 74681478100a..0dd0af30d6a0 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -114,7 +114,7 @@ struct cpu_evtchn_s {
 static __initdata struct cpu_evtchn_s init_evtchn_mask = {
 	.bits[0 ... (NR_EVENT_CHANNELS/BITS_PER_LONG)-1] = ~0ul,
 };
-static struct cpu_evtchn_s *cpu_evtchn_mask_p = &init_evtchn_mask;
+static struct cpu_evtchn_s __refdata *cpu_evtchn_mask_p = &init_evtchn_mask;
 
 static inline unsigned long *cpu_evtchn_mask(int cpu)
 {
@@ -277,7 +277,7 @@ static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 
 	BUG_ON(irq == -1);
 #ifdef CONFIG_SMP
-	cpumask_copy(irq_to_desc(irq)->affinity, cpumask_of(cpu));
+	cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));
 #endif
 
 	clear_bit(chn, cpu_evtchn_mask(cpu_from_irq(irq)));
@@ -294,7 +294,7 @@ static void init_evtchn_cpu_bindings(void)
 
 	/* By default all event channels notify CPU#0. */
 	for_each_irq_desc(i, desc) {
-		cpumask_copy(desc->affinity, cpumask_of(0));
+		cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
 	}
 #endif
 
@@ -376,81 +376,69 @@ static void unmask_evtchn(int port)
 	put_cpu();
 }
 
-static int get_nr_hw_irqs(void)
+static int xen_allocate_irq_dynamic(void)
 {
-	int ret = 1;
+	int first = 0;
+	int irq;
 
 #ifdef CONFIG_X86_IO_APIC
-	ret = get_nr_irqs_gsi();
+	/*
+	 * For an HVM guest or domain 0 which see "real" (emulated or
+	 * actual repectively) GSIs we allocate dynamic IRQs
+	 * e.g. those corresponding to event channels or MSIs
+	 * etc. from the range above those "real" GSIs to avoid
+	 * collisions.
+	 */
+	if (xen_initial_domain() || xen_hvm_domain())
+		first = get_nr_irqs_gsi();
 #endif
 
-	return ret;
-}
+retry:
+	irq = irq_alloc_desc_from(first, -1);
 
-static int find_unbound_pirq(int type)
-{
-	int rc, i;
-	struct physdev_get_free_pirq op_get_free_pirq;
-	op_get_free_pirq.type = type;
+	if (irq == -ENOMEM && first > NR_IRQS_LEGACY) {
+		printk(KERN_ERR "Out of dynamic IRQ space and eating into GSI space. You should increase nr_irqs\n");
+		first = max(NR_IRQS_LEGACY, first - NR_IRQS_LEGACY);
+		goto retry;
+	}
 
-	rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
-	if (!rc)
-		return op_get_free_pirq.pirq;
+	if (irq < 0)
+		panic("No available IRQ to bind to: increase nr_irqs!\n");
 
-	for (i = 0; i < nr_irqs; i++) {
-		if (pirq_to_irq[i] < 0)
-			return i;
-	}
-	return -1;
+	return irq;
 }
 
-static int find_unbound_irq(void)
+static int xen_allocate_irq_gsi(unsigned gsi)
 {
-	struct irq_data *data;
-	int irq, res;
-	int bottom = get_nr_hw_irqs();
-	int top = nr_irqs-1;
-
-	if (bottom == nr_irqs)
-		goto no_irqs;
+	int irq;
 
-	/* This loop starts from the top of IRQ space and goes down.
-	 * We need this b/c if we have a PCI device in a Xen PV guest
-	 * we do not have an IO-APIC (though the backend might have them)
-	 * mapped in. To not have a collision of physical IRQs with the Xen
-	 * event channels start at the top of the IRQ space for virtual IRQs.
+	/*
+	 * A PV guest has no concept of a GSI (since it has no ACPI
+	 * nor access to/knowledge of the physical APICs). Therefore
+	 * all IRQs are dynamically allocated from the entire IRQ
+	 * space.
 	 */
-	for (irq = top; irq > bottom; irq--) {
-		data = irq_get_irq_data(irq);
-		/* only 15->0 have init'd desc; handle irq > 16 */
-		if (!data)
-			break;
-		if (data->chip == &no_irq_chip)
-			break;
-		if (data->chip != &xen_dynamic_chip)
-			continue;
-		if (irq_info[irq].type == IRQT_UNBOUND)
-			return irq;
-	}
+	if (xen_pv_domain() && !xen_initial_domain())
+		return xen_allocate_irq_dynamic();
 
-	if (irq == bottom)
-		goto no_irqs;
+	/* Legacy IRQ descriptors are already allocated by the arch. */
+	if (gsi < NR_IRQS_LEGACY)
+		return gsi;
 
-	res = irq_alloc_desc_at(irq, -1);
-
-	if (WARN_ON(res != irq))
-		return -1;
+	irq = irq_alloc_desc_at(gsi, -1);
+	if (irq < 0)
+		panic("Unable to allocate to IRQ%d (%d)\n", gsi, irq);
 
 	return irq;
-
-no_irqs:
-	panic("No available IRQ to bind to: increase nr_irqs!\n");
 }
 
-static bool identity_mapped_irq(unsigned irq)
+static void xen_free_irq(unsigned irq)
 {
-	/* identity map all the hardware irqs */
-	return irq < get_nr_hw_irqs();
+	/* Legacy IRQ descriptors are managed by the arch. */
+	if (irq < NR_IRQS_LEGACY)
+		return;
+
+	irq_free_desc(irq);
 }
 
 static void pirq_unmask_notify(int irq)
@@ -486,7 +474,7 @@ static bool probing_irq(int irq)
 	return desc && desc->action == NULL;
 }
 
-static unsigned int startup_pirq(unsigned int irq)
+static unsigned int __startup_pirq(unsigned int irq)
 {
 	struct evtchn_bind_pirq bind_pirq;
 	struct irq_info *info = info_for_irq(irq);
@@ -524,9 +512,15 @@ out:
 	return 0;
 }
 
-static void shutdown_pirq(unsigned int irq)
+static unsigned int startup_pirq(struct irq_data *data)
+{
+	return __startup_pirq(data->irq);
+}
+
+static void shutdown_pirq(struct irq_data *data)
 {
 	struct evtchn_close close;
+	unsigned int irq = data->irq;
 	struct irq_info *info = info_for_irq(irq);
 	int evtchn = evtchn_from_irq(irq);
 
@@ -546,20 +540,20 @@ static void shutdown_pirq(unsigned int irq)
 	info->evtchn = 0;
 }
 
-static void enable_pirq(unsigned int irq)
+static void enable_pirq(struct irq_data *data)
 {
-	startup_pirq(irq);
+	startup_pirq(data);
 }
 
-static void disable_pirq(unsigned int irq)
+static void disable_pirq(struct irq_data *data)
 {
 }
 
-static void ack_pirq(unsigned int irq)
+static void ack_pirq(struct irq_data *data)
 {
-	int evtchn = evtchn_from_irq(irq);
+	int evtchn = evtchn_from_irq(data->irq);
 
-	move_native_irq(irq);
+	move_native_irq(data->irq);
 
 	if (VALID_EVTCHN(evtchn)) {
 		mask_evtchn(evtchn);
@@ -567,23 +561,6 @@ static void ack_pirq(unsigned int irq)
 	}
 }
 
-static void end_pirq(unsigned int irq)
-{
-	int evtchn = evtchn_from_irq(irq);
-	struct irq_desc *desc = irq_to_desc(irq);
-
-	if (WARN_ON(!desc))
-		return;
-
-	if ((desc->status & (IRQ_DISABLED|IRQ_PENDING)) ==
-	    (IRQ_DISABLED|IRQ_PENDING)) {
-		shutdown_pirq(irq);
-	} else if (VALID_EVTCHN(evtchn)) {
-		unmask_evtchn(evtchn);
-		pirq_unmask_notify(irq);
-	}
-}
-
 static int find_irq_by_gsi(unsigned gsi)
 {
 	int irq;
@@ -638,14 +615,7 @@ int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name)
 		goto out;	/* XXX need refcount? */
 	}
 
-	/* If we are a PV guest, we don't have GSIs (no ACPI passed). Therefore
-	 * we are using the !xen_initial_domain() to drop in the function.*/
-	if (identity_mapped_irq(gsi) || (!xen_initial_domain() &&
-				xen_pv_domain())) {
-		irq = gsi;
-		irq_alloc_desc_at(irq, -1);
-	} else
-		irq = find_unbound_irq();
+	irq = xen_allocate_irq_gsi(gsi);
 
 	set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
 				      handle_level_irq, name);
@@ -658,7 +628,7 @@ int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name)
 	 * this in the priv domain. */
 	if (xen_initial_domain() &&
 	    HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
-		irq_free_desc(irq);
+		xen_free_irq(irq);
 		irq = -ENOSPC;
 		goto out;
 	}
@@ -674,87 +644,46 @@ out:
 }
 
 #ifdef CONFIG_PCI_MSI
-#include <linux/msi.h>
-#include "../pci/msi.h"
-
-void xen_allocate_pirq_msi(char *name, int *irq, int *pirq, int alloc)
+int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
 {
-	spin_lock(&irq_mapping_update_lock);
-
-	if (alloc & XEN_ALLOC_IRQ) {
-		*irq = find_unbound_irq();
-		if (*irq == -1)
-			goto out;
-	}
-
-	if (alloc & XEN_ALLOC_PIRQ) {
-		*pirq = find_unbound_pirq(MAP_PIRQ_TYPE_MSI);
-		if (*pirq == -1)
-			goto out;
-	}
+	int rc;
+	struct physdev_get_free_pirq op_get_free_pirq;
 
-	set_irq_chip_and_handler_name(*irq, &xen_pirq_chip,
-				      handle_level_irq, name);
+	op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
+	rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
 
-	irq_info[*irq] = mk_pirq_info(0, *pirq, 0, 0);
-	pirq_to_irq[*pirq] = *irq;
+	WARN_ONCE(rc == -ENOSYS,
+		  "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
 
-out:
-	spin_unlock(&irq_mapping_update_lock);
+	return rc ? -1 : op_get_free_pirq.pirq;
 }
 
-int xen_create_msi_irq(struct pci_dev *dev, struct msi_desc *msidesc, int type)
+int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
+			     int pirq, int vector, const char *name)
 {
-	int irq = -1;
-	struct physdev_map_pirq map_irq;
-	int rc;
-	int pos;
-	u32 table_offset, bir;
-
-	memset(&map_irq, 0, sizeof(map_irq));
-	map_irq.domid = DOMID_SELF;
-	map_irq.type = MAP_PIRQ_TYPE_MSI;
-	map_irq.index = -1;
-	map_irq.pirq = -1;
-	map_irq.bus = dev->bus->number;
-	map_irq.devfn = dev->devfn;
-
-	if (type == PCI_CAP_ID_MSIX) {
-		pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
-
-		pci_read_config_dword(dev, msix_table_offset_reg(pos),
-					&table_offset);
-		bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
-
-		map_irq.table_base = pci_resource_start(dev, bir);
-		map_irq.entry_nr = msidesc->msi_attrib.entry_nr;
-	}
+	int irq, ret;
 
 	spin_lock(&irq_mapping_update_lock);
 
-	irq = find_unbound_irq();
-
+	irq = xen_allocate_irq_dynamic();
 	if (irq == -1)
 		goto out;
 
-	rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
-	if (rc) {
-		printk(KERN_WARNING "xen map irq failed %d\n", rc);
-
-		irq_free_desc(irq);
-
-		irq = -1;
-		goto out;
-	}
-	irq_info[irq] = mk_pirq_info(0, map_irq.pirq, 0, map_irq.index);
-
 	set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
-			handle_level_irq,
-			(type == PCI_CAP_ID_MSIX) ? "msi-x":"msi");
+				      handle_level_irq, name);
 
+	irq_info[irq] = mk_pirq_info(0, pirq, 0, vector);
+	pirq_to_irq[pirq] = irq;
+	ret = set_irq_msi(irq, msidesc);
+	if (ret < 0)
+		goto error_irq;
 out:
 	spin_unlock(&irq_mapping_update_lock);
 	return irq;
+error_irq:
+	spin_unlock(&irq_mapping_update_lock);
+	xen_free_irq(irq);
+	return -1;
 }
 #endif
 
@@ -779,11 +708,12 @@ int xen_destroy_irq(int irq)
 			printk(KERN_WARNING "unmap irq failed %d\n", rc);
 			goto out;
 		}
-		pirq_to_irq[info->u.pirq.pirq] = -1;
 	}
+	pirq_to_irq[info->u.pirq.pirq] = -1;
+
 	irq_info[irq] = mk_unbound_info();
 
-	irq_free_desc(irq);
+	xen_free_irq(irq);
 
 out:
 	spin_unlock(&irq_mapping_update_lock);
@@ -814,7 +744,7 @@ int bind_evtchn_to_irq(unsigned int evtchn)
 	irq = evtchn_to_irq[evtchn];
 
 	if (irq == -1) {
-		irq = find_unbound_irq();
+		irq = xen_allocate_irq_dynamic();
 
 		set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
 					      handle_fasteoi_irq, "event");
@@ -839,7 +769,7 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 	irq = per_cpu(ipi_to_irq, cpu)[ipi];
 
 	if (irq == -1) {
-		irq = find_unbound_irq();
+		irq = xen_allocate_irq_dynamic();
 		if (irq < 0)
 			goto out;
 
@@ -864,6 +794,21 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 	return irq;
 }
 
+static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
+					  unsigned int remote_port)
+{
+	struct evtchn_bind_interdomain bind_interdomain;
+	int err;
+
+	bind_interdomain.remote_dom  = remote_domain;
+	bind_interdomain.remote_port = remote_port;
+
+	err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
+					  &bind_interdomain);
+
+	return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
+}
+
 
 int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 {
@@ -875,7 +820,7 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 	irq = per_cpu(virq_to_irq, cpu)[virq];
 
 	if (irq == -1) {
-		irq = find_unbound_irq();
+		irq = xen_allocate_irq_dynamic();
 
 		set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
 					      handle_percpu_irq, "virq");
@@ -934,7 +879,7 @@ static void unbind_from_irq(unsigned int irq)
 	if (irq_info[irq].type != IRQT_UNBOUND) {
 		irq_info[irq] = mk_unbound_info();
 
-		irq_free_desc(irq);
+		xen_free_irq(irq);
 	}
 
 	spin_unlock(&irq_mapping_update_lock);
@@ -959,6 +904,29 @@ int bind_evtchn_to_irqhandler(unsigned int evtchn,
 }
 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
 
+int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
+					  unsigned int remote_port,
+					  irq_handler_t handler,
+					  unsigned long irqflags,
+					  const char *devname,
+					  void *dev_id)
+{
+	int irq, retval;
+
+	irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
+	if (irq < 0)
+		return irq;
+
+	retval = request_irq(irq, handler, irqflags, devname, dev_id);
+	if (retval != 0) {
+		unbind_from_irq(irq);
+		return retval;
+	}
+
+	return irq;
+}
+EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
+
 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
 			    irq_handler_t handler,
 			    unsigned long irqflags, const char *devname, void *dev_id)
@@ -990,7 +958,7 @@ int bind_ipi_to_irqhandler(enum ipi_vector ipi,
 	if (irq < 0)
 		return irq;
 
-	irqflags |= IRQF_NO_SUSPEND;
+	irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME;
 	retval = request_irq(irq, handler, irqflags, devname, dev_id);
 	if (retval != 0) {
 		unbind_from_irq(irq);
@@ -1234,11 +1202,12 @@ static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
 	return 0;
 }
 
-static int set_affinity_irq(unsigned irq, const struct cpumask *dest)
+static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
+			    bool force)
 {
 	unsigned tcpu = cpumask_first(dest);
 
-	return rebind_irq_to_cpu(irq, tcpu);
+	return rebind_irq_to_cpu(data->irq, tcpu);
 }
 
 int resend_irq_on_evtchn(unsigned int irq)
@@ -1257,35 +1226,35 @@ int resend_irq_on_evtchn(unsigned int irq)
 	return 1;
 }
 
-static void enable_dynirq(unsigned int irq)
+static void enable_dynirq(struct irq_data *data)
 {
-	int evtchn = evtchn_from_irq(irq);
+	int evtchn = evtchn_from_irq(data->irq);
 
 	if (VALID_EVTCHN(evtchn))
 		unmask_evtchn(evtchn);
 }
 
-static void disable_dynirq(unsigned int irq)
+static void disable_dynirq(struct irq_data *data)
 {
-	int evtchn = evtchn_from_irq(irq);
+	int evtchn = evtchn_from_irq(data->irq);
 
 	if (VALID_EVTCHN(evtchn))
 		mask_evtchn(evtchn);
 }
 
-static void ack_dynirq(unsigned int irq)
+static void ack_dynirq(struct irq_data *data)
 {
-	int evtchn = evtchn_from_irq(irq);
+	int evtchn = evtchn_from_irq(data->irq);
 
-	move_masked_irq(irq);
+	move_masked_irq(data->irq);
 
 	if (VALID_EVTCHN(evtchn))
 		unmask_evtchn(evtchn);
 }
 
-static int retrigger_dynirq(unsigned int irq)
+static int retrigger_dynirq(struct irq_data *data)
 {
-	int evtchn = evtchn_from_irq(irq);
+	int evtchn = evtchn_from_irq(data->irq);
 	struct shared_info *sh = HYPERVISOR_shared_info;
 	int ret = 0;
 
@@ -1334,7 +1303,7 @@ static void restore_cpu_pirqs(void)
 
 		printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
 
-		startup_pirq(irq);
+		__startup_pirq(irq);
 	}
 }
 
@@ -1445,7 +1414,6 @@ void xen_poll_irq(int irq)
 void xen_irq_resume(void)
 {
 	unsigned int cpu, irq, evtchn;
-	struct irq_desc *desc;
 
 	init_evtchn_cpu_bindings();
 
@@ -1465,66 +1433,48 @@ void xen_irq_resume(void)
 		restore_cpu_ipis(cpu);
 	}
 
-	/*
-	 * Unmask any IRQF_NO_SUSPEND IRQs which are enabled. These
-	 * are not handled by the IRQ core.
-	 */
-	for_each_irq_desc(irq, desc) {
-		if (!desc->action || !(desc->action->flags & IRQF_NO_SUSPEND))
-			continue;
-		if (desc->status & IRQ_DISABLED)
-			continue;
-
-		evtchn = evtchn_from_irq(irq);
-		if (evtchn == -1)
-			continue;
-
-		unmask_evtchn(evtchn);
-	}
-
 	restore_cpu_pirqs();
 }
 
 static struct irq_chip xen_dynamic_chip __read_mostly = {
-	.name		= "xen-dyn",
+	.name			= "xen-dyn",
 
-	.disable	= disable_dynirq,
-	.mask		= disable_dynirq,
-	.unmask		= enable_dynirq,
+	.irq_disable		= disable_dynirq,
+	.irq_mask		= disable_dynirq,
+	.irq_unmask		= enable_dynirq,
 
-	.eoi		= ack_dynirq,
-	.set_affinity	= set_affinity_irq,
-	.retrigger	= retrigger_dynirq,
+	.irq_eoi		= ack_dynirq,
+	.irq_set_affinity	= set_affinity_irq,
+	.irq_retrigger		= retrigger_dynirq,
 };
 
 static struct irq_chip xen_pirq_chip __read_mostly = {
-	.name		= "xen-pirq",
+	.name			= "xen-pirq",
 
-	.startup	= startup_pirq,
-	.shutdown	= shutdown_pirq,
+	.irq_startup		= startup_pirq,
+	.irq_shutdown		= shutdown_pirq,
 
-	.enable		= enable_pirq,
-	.unmask		= enable_pirq,
+	.irq_enable		= enable_pirq,
+	.irq_unmask		= enable_pirq,
 
-	.disable	= disable_pirq,
-	.mask		= disable_pirq,
+	.irq_disable		= disable_pirq,
+	.irq_mask		= disable_pirq,
 
-	.ack		= ack_pirq,
-	.end		= end_pirq,
+	.irq_ack		= ack_pirq,
 
-	.set_affinity	= set_affinity_irq,
+	.irq_set_affinity	= set_affinity_irq,
 
-	.retrigger	= retrigger_dynirq,
+	.irq_retrigger		= retrigger_dynirq,
 };
 
 static struct irq_chip xen_percpu_chip __read_mostly = {
-	.name		= "xen-percpu",
+	.name			= "xen-percpu",
 
-	.disable	= disable_dynirq,
-	.mask		= disable_dynirq,
-	.unmask		= enable_dynirq,
+	.irq_disable		= disable_dynirq,
+	.irq_mask		= disable_dynirq,
+	.irq_unmask		= enable_dynirq,
 
-	.ack		= ack_dynirq,
+	.irq_ack		= ack_dynirq,
 };
 
 int xen_set_callback_via(uint64_t via)
diff --git a/drivers/xen/gntalloc.c b/drivers/xen/gntalloc.c
new file mode 100644
index 000000000000..a7ffdfe19fc9
--- /dev/null
+++ b/drivers/xen/gntalloc.c
@@ -0,0 +1,545 @@
+/******************************************************************************
+ * gntalloc.c
+ *
+ * Device for creating grant references (in user-space) that may be shared
+ * with other domains.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ * This driver exists to allow userspace programs in Linux to allocate kernel
+ * memory that will later be shared with another domain.  Without this device,
+ * Linux userspace programs cannot create grant references.
+ *
+ * How this stuff works:
+ *   X -> granting a page to Y
+ *   Y -> mapping the grant from X
+ *
+ *   1. X uses the gntalloc device to allocate a page of kernel memory, P.
+ *   2. X creates an entry in the grant table that says domid(Y) can access P.
+ *      This is done without a hypercall unless the grant table needs expansion.
+ *   3. X gives the grant reference identifier, GREF, to Y.
+ *   4. Y maps the page, either directly into kernel memory for use in a backend
+ *      driver, or via a the gntdev device to map into the address space of an
+ *      application running in Y. This is the first point at which Xen does any
+ *      tracking of the page.
+ *   5. A program in X mmap()s a segment of the gntalloc device that corresponds
+ *      to the shared page, and can now communicate with Y over the shared page.
+ *
+ *
+ * NOTE TO USERSPACE LIBRARIES:
+ *   The grant allocation and mmap()ing are, naturally, two separate operations.
+ *   You set up the sharing by calling the create ioctl() and then the mmap().
+ *   Teardown requires munmap() and either close() or ioctl().
+ *
+ * WARNING: Since Xen does not allow a guest to forcibly end the use of a grant
+ * reference, this device can be used to consume kernel memory by leaving grant
+ * references mapped by another domain when an application exits. Therefore,
+ * there is a global limit on the number of pages that can be allocated. When
+ * all references to the page are unmapped, it will be freed during the next
+ * grant operation.
+ */
+
+#include <linux/atomic.h>
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/mm.h>
+#include <linux/uaccess.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/highmem.h>
+
+#include <xen/xen.h>
+#include <xen/page.h>
+#include <xen/grant_table.h>
+#include <xen/gntalloc.h>
+#include <xen/events.h>
+
+static int limit = 1024;
+module_param(limit, int, 0644);
+MODULE_PARM_DESC(limit, "Maximum number of grants that may be allocated by "
+		"the gntalloc device");
+
+static LIST_HEAD(gref_list);
+static DEFINE_SPINLOCK(gref_lock);
+static int gref_size;
+
+struct notify_info {
+	uint16_t pgoff:12;    /* Bits 0-11: Offset of the byte to clear */
+	uint16_t flags:2;     /* Bits 12-13: Unmap notification flags */
+	int event;            /* Port (event channel) to notify */
+};
+
+/* Metadata on a grant reference. */
+struct gntalloc_gref {
+	struct list_head next_gref;  /* list entry gref_list */
+	struct list_head next_file;  /* list entry file->list, if open */
+	struct page *page;	     /* The shared page */
+	uint64_t file_index;         /* File offset for mmap() */
+	unsigned int users;          /* Use count - when zero, waiting on Xen */
+	grant_ref_t gref_id;         /* The grant reference number */
+	struct notify_info notify;   /* Unmap notification */
+};
+
+struct gntalloc_file_private_data {
+	struct list_head list;
+	uint64_t index;
+};
+
+static void __del_gref(struct gntalloc_gref *gref);
+
+static void do_cleanup(void)
+{
+	struct gntalloc_gref *gref, *n;
+	list_for_each_entry_safe(gref, n, &gref_list, next_gref) {
+		if (!gref->users)
+			__del_gref(gref);
+	}
+}
+
+static int add_grefs(struct ioctl_gntalloc_alloc_gref *op,
+	uint32_t *gref_ids, struct gntalloc_file_private_data *priv)
+{
+	int i, rc, readonly;
+	LIST_HEAD(queue_gref);
+	LIST_HEAD(queue_file);
+	struct gntalloc_gref *gref;
+
+	readonly = !(op->flags & GNTALLOC_FLAG_WRITABLE);
+	rc = -ENOMEM;
+	for (i = 0; i < op->count; i++) {
+		gref = kzalloc(sizeof(*gref), GFP_KERNEL);
+		if (!gref)
+			goto undo;
+		list_add_tail(&gref->next_gref, &queue_gref);
+		list_add_tail(&gref->next_file, &queue_file);
+		gref->users = 1;
+		gref->file_index = op->index + i * PAGE_SIZE;
+		gref->page = alloc_page(GFP_KERNEL|__GFP_ZERO);
+		if (!gref->page)
+			goto undo;
+
+		/* Grant foreign access to the page. */
+		gref->gref_id = gnttab_grant_foreign_access(op->domid,
+			pfn_to_mfn(page_to_pfn(gref->page)), readonly);
+		if (gref->gref_id < 0) {
+			rc = gref->gref_id;
+			goto undo;
+		}
+		gref_ids[i] = gref->gref_id;
+	}
+
+	/* Add to gref lists. */
+	spin_lock(&gref_lock);
+	list_splice_tail(&queue_gref, &gref_list);
+	list_splice_tail(&queue_file, &priv->list);
+	spin_unlock(&gref_lock);
+
+	return 0;
+
+undo:
+	spin_lock(&gref_lock);
+	gref_size -= (op->count - i);
+
+	list_for_each_entry(gref, &queue_file, next_file) {
+		/* __del_gref does not remove from queue_file */
+		__del_gref(gref);
+	}
+
+	/* It's possible for the target domain to map the just-allocated grant
+	 * references by blindly guessing their IDs; if this is done, then
+	 * __del_gref will leave them in the queue_gref list. They need to be
+	 * added to the global list so that we can free them when they are no
+	 * longer referenced.
+	 */
+	if (unlikely(!list_empty(&queue_gref)))
+		list_splice_tail(&queue_gref, &gref_list);
+	spin_unlock(&gref_lock);
+	return rc;
+}
+
+static void __del_gref(struct gntalloc_gref *gref)
+{
+	if (gref->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
+		uint8_t *tmp = kmap(gref->page);
+		tmp[gref->notify.pgoff] = 0;
+		kunmap(gref->page);
+	}
+	if (gref->notify.flags & UNMAP_NOTIFY_SEND_EVENT)
+		notify_remote_via_evtchn(gref->notify.event);
+
+	gref->notify.flags = 0;
+
+	if (gref->gref_id > 0) {
+		if (gnttab_query_foreign_access(gref->gref_id))
+			return;
+
+		if (!gnttab_end_foreign_access_ref(gref->gref_id, 0))
+			return;
+	}
+
+	gref_size--;
+	list_del(&gref->next_gref);
+
+	if (gref->page)
+		__free_page(gref->page);
+
+	kfree(gref);
+}
+
+/* finds contiguous grant references in a file, returns the first */
+static struct gntalloc_gref *find_grefs(struct gntalloc_file_private_data *priv,
+		uint64_t index, uint32_t count)
+{
+	struct gntalloc_gref *rv = NULL, *gref;
+	list_for_each_entry(gref, &priv->list, next_file) {
+		if (gref->file_index == index && !rv)
+			rv = gref;
+		if (rv) {
+			if (gref->file_index != index)
+				return NULL;
+			index += PAGE_SIZE;
+			count--;
+			if (count == 0)
+				return rv;
+		}
+	}
+	return NULL;
+}
+
+/*
+ * -------------------------------------
+ *  File operations.
+ * -------------------------------------
+ */
+static int gntalloc_open(struct inode *inode, struct file *filp)
+{
+	struct gntalloc_file_private_data *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		goto out_nomem;
+	INIT_LIST_HEAD(&priv->list);
+
+	filp->private_data = priv;
+
+	pr_debug("%s: priv %p\n", __func__, priv);
+
+	return 0;
+
+out_nomem:
+	return -ENOMEM;
+}
+
+static int gntalloc_release(struct inode *inode, struct file *filp)
+{
+	struct gntalloc_file_private_data *priv = filp->private_data;
+	struct gntalloc_gref *gref;
+
+	pr_debug("%s: priv %p\n", __func__, priv);
+
+	spin_lock(&gref_lock);
+	while (!list_empty(&priv->list)) {
+		gref = list_entry(priv->list.next,
+			struct gntalloc_gref, next_file);
+		list_del(&gref->next_file);
+		gref->users--;
+		if (gref->users == 0)
+			__del_gref(gref);
+	}
+	kfree(priv);
+	spin_unlock(&gref_lock);
+
+	return 0;
+}
+
+static long gntalloc_ioctl_alloc(struct gntalloc_file_private_data *priv,
+		struct ioctl_gntalloc_alloc_gref __user *arg)
+{
+	int rc = 0;
+	struct ioctl_gntalloc_alloc_gref op;
+	uint32_t *gref_ids;
+
+	pr_debug("%s: priv %p\n", __func__, priv);
+
+	if (copy_from_user(&op, arg, sizeof(op))) {
+		rc = -EFAULT;
+		goto out;
+	}
+
+	gref_ids = kzalloc(sizeof(gref_ids[0]) * op.count, GFP_TEMPORARY);
+	if (!gref_ids) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	spin_lock(&gref_lock);
+	/* Clean up pages that were at zero (local) users but were still mapped
+	 * by remote domains. Since those pages count towards the limit that we
+	 * are about to enforce, removing them here is a good idea.
+	 */
+	do_cleanup();
+	if (gref_size + op.count > limit) {
+		spin_unlock(&gref_lock);
+		rc = -ENOSPC;
+		goto out_free;
+	}
+	gref_size += op.count;
+	op.index = priv->index;
+	priv->index += op.count * PAGE_SIZE;
+	spin_unlock(&gref_lock);
+
+	rc = add_grefs(&op, gref_ids, priv);
+	if (rc < 0)
+		goto out_free;
+
+	/* Once we finish add_grefs, it is unsafe to touch the new reference,
+	 * since it is possible for a concurrent ioctl to remove it (by guessing
+	 * its index). If the userspace application doesn't provide valid memory
+	 * to write the IDs to, then it will need to close the file in order to
+	 * release - which it will do by segfaulting when it tries to access the
+	 * IDs to close them.
+	 */
+	if (copy_to_user(arg, &op, sizeof(op))) {
+		rc = -EFAULT;
+		goto out_free;
+	}
+	if (copy_to_user(arg->gref_ids, gref_ids,
+			sizeof(gref_ids[0]) * op.count)) {
+		rc = -EFAULT;
+		goto out_free;
+	}
+
+out_free:
+	kfree(gref_ids);
+out:
+	return rc;
+}
+
+static long gntalloc_ioctl_dealloc(struct gntalloc_file_private_data *priv,
+		void __user *arg)
+{
+	int i, rc = 0;
+	struct ioctl_gntalloc_dealloc_gref op;
+	struct gntalloc_gref *gref, *n;
+
+	pr_debug("%s: priv %p\n", __func__, priv);
+
+	if (copy_from_user(&op, arg, sizeof(op))) {
+		rc = -EFAULT;
+		goto dealloc_grant_out;
+	}
+
+	spin_lock(&gref_lock);
+	gref = find_grefs(priv, op.index, op.count);
+	if (gref) {
+		/* Remove from the file list only, and decrease reference count.
+		 * The later call to do_cleanup() will remove from gref_list and
+		 * free the memory if the pages aren't mapped anywhere.
+		 */
+		for (i = 0; i < op.count; i++) {
+			n = list_entry(gref->next_file.next,
+				struct gntalloc_gref, next_file);
+			list_del(&gref->next_file);
+			gref->users--;
+			gref = n;
+		}
+	} else {
+		rc = -EINVAL;
+	}
+
+	do_cleanup();
+
+	spin_unlock(&gref_lock);
+dealloc_grant_out:
+	return rc;
+}
+
+static long gntalloc_ioctl_unmap_notify(struct gntalloc_file_private_data *priv,
+		void __user *arg)
+{
+	struct ioctl_gntalloc_unmap_notify op;
+	struct gntalloc_gref *gref;
+	uint64_t index;
+	int pgoff;
+	int rc;
+
+	if (copy_from_user(&op, arg, sizeof(op)))
+		return -EFAULT;
+
+	index = op.index & ~(PAGE_SIZE - 1);
+	pgoff = op.index & (PAGE_SIZE - 1);
+
+	spin_lock(&gref_lock);
+
+	gref = find_grefs(priv, index, 1);
+	if (!gref) {
+		rc = -ENOENT;
+		goto unlock_out;
+	}
+
+	if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT)) {
+		rc = -EINVAL;
+		goto unlock_out;
+	}
+
+	gref->notify.flags = op.action;
+	gref->notify.pgoff = pgoff;
+	gref->notify.event = op.event_channel_port;
+	rc = 0;
+ unlock_out:
+	spin_unlock(&gref_lock);
+	return rc;
+}
+
+static long gntalloc_ioctl(struct file *filp, unsigned int cmd,
+		unsigned long arg)
+{
+	struct gntalloc_file_private_data *priv = filp->private_data;
+
+	switch (cmd) {
+	case IOCTL_GNTALLOC_ALLOC_GREF:
+		return gntalloc_ioctl_alloc(priv, (void __user *)arg);
+
+	case IOCTL_GNTALLOC_DEALLOC_GREF:
+		return gntalloc_ioctl_dealloc(priv, (void __user *)arg);
+
+	case IOCTL_GNTALLOC_SET_UNMAP_NOTIFY:
+		return gntalloc_ioctl_unmap_notify(priv, (void __user *)arg);
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+static void gntalloc_vma_close(struct vm_area_struct *vma)
+{
+	struct gntalloc_gref *gref = vma->vm_private_data;
+	if (!gref)
+		return;
+
+	spin_lock(&gref_lock);
+	gref->users--;
+	if (gref->users == 0)
+		__del_gref(gref);
+	spin_unlock(&gref_lock);
+}
+
+static struct vm_operations_struct gntalloc_vmops = {
+	.close = gntalloc_vma_close,
+};
+
+static int gntalloc_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	struct gntalloc_file_private_data *priv = filp->private_data;
+	struct gntalloc_gref *gref;
+	int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+	int rv, i;
+
+	pr_debug("%s: priv %p, page %lu+%d\n", __func__,
+		       priv, vma->vm_pgoff, count);
+
+	if (!(vma->vm_flags & VM_SHARED)) {
+		printk(KERN_ERR "%s: Mapping must be shared.\n", __func__);
+		return -EINVAL;
+	}
+
+	spin_lock(&gref_lock);
+	gref = find_grefs(priv, vma->vm_pgoff << PAGE_SHIFT, count);
+	if (gref == NULL) {
+		rv = -ENOENT;
+		pr_debug("%s: Could not find grant reference",
+				__func__);
+		goto out_unlock;
+	}
+
+	vma->vm_private_data = gref;
+
+	vma->vm_flags |= VM_RESERVED;
+	vma->vm_flags |= VM_DONTCOPY;
+	vma->vm_flags |= VM_PFNMAP | VM_PFN_AT_MMAP;
+
+	vma->vm_ops = &gntalloc_vmops;
+
+	for (i = 0; i < count; i++) {
+		gref->users++;
+		rv = vm_insert_page(vma, vma->vm_start + i * PAGE_SIZE,
+				gref->page);
+		if (rv)
+			goto out_unlock;
+
+		gref = list_entry(gref->next_file.next,
+				struct gntalloc_gref, next_file);
+	}
+	rv = 0;
+
+out_unlock:
+	spin_unlock(&gref_lock);
+	return rv;
+}
+
+static const struct file_operations gntalloc_fops = {
+	.owner = THIS_MODULE,
+	.open = gntalloc_open,
+	.release = gntalloc_release,
+	.unlocked_ioctl = gntalloc_ioctl,
+	.mmap = gntalloc_mmap
+};
+
+/*
+ * -------------------------------------
+ * Module creation/destruction.
+ * -------------------------------------
+ */
+static struct miscdevice gntalloc_miscdev = {
+	.minor	= MISC_DYNAMIC_MINOR,
+	.name	= "xen/gntalloc",
+	.fops	= &gntalloc_fops,
+};
+
+static int __init gntalloc_init(void)
+{
+	int err;
+
+	if (!xen_domain())
+		return -ENODEV;
+
+	err = misc_register(&gntalloc_miscdev);
+	if (err != 0) {
+		printk(KERN_ERR "Could not register misc gntalloc device\n");
+		return err;
+	}
+
+	pr_debug("Created grant allocation device at %d,%d\n",
+			MISC_MAJOR, gntalloc_miscdev.minor);
+
+	return 0;
+}
+
+static void __exit gntalloc_exit(void)
+{
+	misc_deregister(&gntalloc_miscdev);
+}
+
+module_init(gntalloc_init);
+module_exit(gntalloc_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Carter Weatherly <carter.weatherly@jhuapl.edu>, "
+		"Daniel De Graaf <dgdegra@tycho.nsa.gov>");
+MODULE_DESCRIPTION("User-space grant reference allocator driver");
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 1e31cdcdae1e..d43ff3072c99 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -32,10 +32,12 @@
 #include <linux/sched.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
+#include <linux/highmem.h>
 
 #include <xen/xen.h>
 #include <xen/grant_table.h>
 #include <xen/gntdev.h>
+#include <xen/events.h>
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
 #include <asm/xen/page.h>
@@ -45,35 +47,46 @@ MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, "
 	      "Gerd Hoffmann <kraxel@redhat.com>");
 MODULE_DESCRIPTION("User-space granted page access driver");
 
-static int limit = 1024;
+static int limit = 1024*1024;
 module_param(limit, int, 0644);
-MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped at "
-		"once by a gntdev instance");
+MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by "
+		"the gntdev device");
+
+static atomic_t pages_mapped = ATOMIC_INIT(0);
+
+static int use_ptemod;
 
 struct gntdev_priv {
 	struct list_head maps;
-	uint32_t used;
-	uint32_t limit;
 	/* lock protects maps from concurrent changes */
 	spinlock_t lock;
 	struct mm_struct *mm;
 	struct mmu_notifier mn;
 };
 
+struct unmap_notify {
+	int flags;
+	/* Address relative to the start of the grant_map */
+	int addr;
+	int event;
+};
+
 struct grant_map {
 	struct list_head next;
-	struct gntdev_priv *priv;
 	struct vm_area_struct *vma;
 	int index;
 	int count;
 	int flags;
-	int is_mapped;
+	atomic_t users;
+	struct unmap_notify notify;
 	struct ioctl_gntdev_grant_ref *grants;
 	struct gnttab_map_grant_ref   *map_ops;
 	struct gnttab_unmap_grant_ref *unmap_ops;
 	struct page **pages;
 };
 
+static int unmap_grant_pages(struct grant_map *map, int offset, int pages);
+
 /* ------------------------------------------------------------------ */
 
 static void gntdev_print_maps(struct gntdev_priv *priv,
@@ -82,9 +95,7 @@ static void gntdev_print_maps(struct gntdev_priv *priv,
 #ifdef DEBUG
 	struct grant_map *map;
 
-	pr_debug("maps list (priv %p, usage %d/%d)\n",
-	       priv, priv->used, priv->limit);
-
+	pr_debug("%s: maps list (priv %p)\n", __func__, priv);
 	list_for_each_entry(map, &priv->maps, next)
 		pr_debug("  index %2d, count %2d %s\n",
 		       map->index, map->count,
@@ -115,14 +126,13 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
 		add->pages[i] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
 		if (add->pages[i] == NULL)
 			goto err;
+		add->map_ops[i].handle = -1;
+		add->unmap_ops[i].handle = -1;
 	}
 
 	add->index = 0;
 	add->count = count;
-	add->priv  = priv;
-
-	if (add->count + priv->used > priv->limit)
-		goto err;
+	atomic_set(&add->users, 1);
 
 	return add;
 
@@ -154,7 +164,6 @@ static void gntdev_add_map(struct gntdev_priv *priv, struct grant_map *add)
 	list_add_tail(&add->next, &priv->maps);
 
 done:
-	priv->used += add->count;
 	gntdev_print_maps(priv, "[new]", add->index);
 }
 
@@ -166,57 +175,57 @@ static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
 	list_for_each_entry(map, &priv->maps, next) {
 		if (map->index != index)
 			continue;
-		if (map->count != count)
-			continue;
-		return map;
-	}
-	return NULL;
-}
-
-static struct grant_map *gntdev_find_map_vaddr(struct gntdev_priv *priv,
-					       unsigned long vaddr)
-{
-	struct grant_map *map;
-
-	list_for_each_entry(map, &priv->maps, next) {
-		if (!map->vma)
-			continue;
-		if (vaddr < map->vma->vm_start)
-			continue;
-		if (vaddr >= map->vma->vm_end)
+		if (count && map->count != count)
 			continue;
 		return map;
 	}
 	return NULL;
 }
 
-static int gntdev_del_map(struct grant_map *map)
+static void gntdev_put_map(struct grant_map *map)
 {
 	int i;
 
-	if (map->vma)
-		return -EBUSY;
-	for (i = 0; i < map->count; i++)
-		if (map->unmap_ops[i].handle)
-			return -EBUSY;
+	if (!map)
+		return;
 
-	map->priv->used -= map->count;
-	list_del(&map->next);
-	return 0;
-}
+	if (!atomic_dec_and_test(&map->users))
+		return;
 
-static void gntdev_free_map(struct grant_map *map)
-{
-	int i;
+	atomic_sub(map->count, &pages_mapped);
 
-	if (!map)
-		return;
+	if (map->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
+		notify_remote_via_evtchn(map->notify.event);
+	}
+
+	if (map->pages) {
+		if (!use_ptemod)
+			unmap_grant_pages(map, 0, map->count);
 
-	if (map->pages)
 		for (i = 0; i < map->count; i++) {
-			if (map->pages[i])
+			uint32_t check, *tmp;
+			if (!map->pages[i])
+				continue;
+			/* XXX When unmapping in an HVM domain, Xen will
+			 * sometimes end up mapping the GFN to an invalid MFN.
+			 * In this case, writes will be discarded and reads will
+			 * return all 0xFF bytes.  Leak these unusable GFNs
+			 * until Xen supports fixing their p2m mapping.
+			 *
+			 * Confirmed present in Xen 4.1-RC3 with HVM source
+			 */
+			tmp = kmap(map->pages[i]);
+			*tmp = 0xdeaddead;
+			mb();
+			check = *tmp;
+			kunmap(map->pages[i]);
+			if (check == 0xdeaddead)
 				__free_page(map->pages[i]);
+			else
+				pr_debug("Discard page %d=%ld\n", i,
+					page_to_pfn(map->pages[i]));
 		}
+	}
 	kfree(map->pages);
 	kfree(map->grants);
 	kfree(map->map_ops);
@@ -231,24 +240,39 @@ static int find_grant_ptes(pte_t *pte, pgtable_t token,
 {
 	struct grant_map *map = data;
 	unsigned int pgnr = (addr - map->vma->vm_start) >> PAGE_SHIFT;
+	int flags = map->flags | GNTMAP_application_map | GNTMAP_contains_pte;
 	u64 pte_maddr;
 
 	BUG_ON(pgnr >= map->count);
 	pte_maddr = arbitrary_virt_to_machine(pte).maddr;
 
-	gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr,
-			  GNTMAP_contains_pte | map->flags,
+	gnttab_set_map_op(&map->map_ops[pgnr], pte_maddr, flags,
 			  map->grants[pgnr].ref,
 			  map->grants[pgnr].domid);
-	gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr,
-			    GNTMAP_contains_pte | map->flags,
-			    0 /* handle */);
+	gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags,
+			    -1 /* handle */);
 	return 0;
 }
 
 static int map_grant_pages(struct grant_map *map)
 {
 	int i, err = 0;
+	phys_addr_t addr;
+
+	if (!use_ptemod) {
+		/* Note: it could already be mapped */
+		if (map->map_ops[0].handle != -1)
+			return 0;
+		for (i = 0; i < map->count; i++) {
+			addr = (phys_addr_t)
+				pfn_to_kaddr(page_to_pfn(map->pages[i]));
+			gnttab_set_map_op(&map->map_ops[i], addr, map->flags,
+				map->grants[i].ref,
+				map->grants[i].domid);
+			gnttab_set_unmap_op(&map->unmap_ops[i], addr,
+				map->flags, -1 /* handle */);
+		}
+	}
 
 	pr_debug("map %d+%d\n", map->index, map->count);
 	err = gnttab_map_refs(map->map_ops, map->pages, map->count);
@@ -258,28 +282,81 @@ static int map_grant_pages(struct grant_map *map)
 	for (i = 0; i < map->count; i++) {
 		if (map->map_ops[i].status)
 			err = -EINVAL;
-		map->unmap_ops[i].handle = map->map_ops[i].handle;
+		else {
+			BUG_ON(map->map_ops[i].handle == -1);
+			map->unmap_ops[i].handle = map->map_ops[i].handle;
+			pr_debug("map handle=%d\n", map->map_ops[i].handle);
+		}
 	}
 	return err;
 }
 
-static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
+static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
 {
 	int i, err = 0;
 
-	pr_debug("map %d+%d [%d+%d]\n", map->index, map->count, offset, pages);
-	err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages, pages);
+	if (map->notify.flags & UNMAP_NOTIFY_CLEAR_BYTE) {
+		int pgno = (map->notify.addr >> PAGE_SHIFT);
+		if (pgno >= offset && pgno < offset + pages && use_ptemod) {
+			void __user *tmp = (void __user *)
+				map->vma->vm_start + map->notify.addr;
+			err = copy_to_user(tmp, &err, 1);
+			if (err)
+				return err;
+			map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
+		} else if (pgno >= offset && pgno < offset + pages) {
+			uint8_t *tmp = kmap(map->pages[pgno]);
+			tmp[map->notify.addr & (PAGE_SIZE-1)] = 0;
+			kunmap(map->pages[pgno]);
+			map->notify.flags &= ~UNMAP_NOTIFY_CLEAR_BYTE;
+		}
+	}
+
+	err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages + offset, pages);
 	if (err)
 		return err;
 
 	for (i = 0; i < pages; i++) {
 		if (map->unmap_ops[offset+i].status)
 			err = -EINVAL;
-		map->unmap_ops[offset+i].handle = 0;
+		pr_debug("unmap handle=%d st=%d\n",
+			map->unmap_ops[offset+i].handle,
+			map->unmap_ops[offset+i].status);
+		map->unmap_ops[offset+i].handle = -1;
 	}
 	return err;
 }
 
+static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
+{
+	int range, err = 0;
+
+	pr_debug("unmap %d+%d [%d+%d]\n", map->index, map->count, offset, pages);
+
+	/* It is possible the requested range will have a "hole" where we
+	 * already unmapped some of the grants. Only unmap valid ranges.
+	 */
+	while (pages && !err) {
+		while (pages && map->unmap_ops[offset].handle == -1) {
+			offset++;
+			pages--;
+		}
+		range = 0;
+		while (range < pages) {
+			if (map->unmap_ops[offset+range].handle == -1) {
+				range--;
+				break;
+			}
+			range++;
+		}
+		err = __unmap_grant_pages(map, offset, range);
+		offset += range;
+		pages -= range;
+	}
+
+	return err;
+}
+
 /* ------------------------------------------------------------------ */
 
 static void gntdev_vma_close(struct vm_area_struct *vma)
@@ -287,22 +364,13 @@ static void gntdev_vma_close(struct vm_area_struct *vma)
 	struct grant_map *map = vma->vm_private_data;
 
 	pr_debug("close %p\n", vma);
-	map->is_mapped = 0;
 	map->vma = NULL;
 	vma->vm_private_data = NULL;
-}
-
-static int gntdev_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
-{
-	pr_debug("vaddr %p, pgoff %ld (shouldn't happen)\n",
-			vmf->virtual_address, vmf->pgoff);
-	vmf->flags = VM_FAULT_ERROR;
-	return 0;
+	gntdev_put_map(map);
 }
 
 static struct vm_operations_struct gntdev_vmops = {
 	.close = gntdev_vma_close,
-	.fault = gntdev_vma_fault,
 };
 
 /* ------------------------------------------------------------------ */
@@ -320,8 +388,6 @@ static void mn_invl_range_start(struct mmu_notifier *mn,
 	list_for_each_entry(map, &priv->maps, next) {
 		if (!map->vma)
 			continue;
-		if (!map->is_mapped)
-			continue;
 		if (map->vma->vm_start >= end)
 			continue;
 		if (map->vma->vm_end <= start)
@@ -386,16 +452,17 @@ static int gntdev_open(struct inode *inode, struct file *flip)
 
 	INIT_LIST_HEAD(&priv->maps);
 	spin_lock_init(&priv->lock);
-	priv->limit = limit;
 
-	priv->mm = get_task_mm(current);
-	if (!priv->mm) {
-		kfree(priv);
-		return -ENOMEM;
+	if (use_ptemod) {
+		priv->mm = get_task_mm(current);
+		if (!priv->mm) {
+			kfree(priv);
+			return -ENOMEM;
+		}
+		priv->mn.ops = &gntdev_mmu_ops;
+		ret = mmu_notifier_register(&priv->mn, priv->mm);
+		mmput(priv->mm);
 	}
-	priv->mn.ops = &gntdev_mmu_ops;
-	ret = mmu_notifier_register(&priv->mn, priv->mm);
-	mmput(priv->mm);
 
 	if (ret) {
 		kfree(priv);
@@ -412,21 +479,19 @@ static int gntdev_release(struct inode *inode, struct file *flip)
 {
 	struct gntdev_priv *priv = flip->private_data;
 	struct grant_map *map;
-	int err;
 
 	pr_debug("priv %p\n", priv);
 
 	spin_lock(&priv->lock);
 	while (!list_empty(&priv->maps)) {
 		map = list_entry(priv->maps.next, struct grant_map, next);
-		err = gntdev_del_map(map);
-		if (WARN_ON(err))
-			gntdev_free_map(map);
-
+		list_del(&map->next);
+		gntdev_put_map(map);
 	}
 	spin_unlock(&priv->lock);
 
-	mmu_notifier_unregister(&priv->mn, priv->mm);
+	if (use_ptemod)
+		mmu_notifier_unregister(&priv->mn, priv->mm);
 	kfree(priv);
 	return 0;
 }
@@ -443,16 +508,21 @@ static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
 	pr_debug("priv %p, add %d\n", priv, op.count);
 	if (unlikely(op.count <= 0))
 		return -EINVAL;
-	if (unlikely(op.count > priv->limit))
-		return -EINVAL;
 
 	err = -ENOMEM;
 	map = gntdev_alloc_map(priv, op.count);
 	if (!map)
 		return err;
+
+	if (unlikely(atomic_add_return(op.count, &pages_mapped) > limit)) {
+		pr_debug("can't map: over limit\n");
+		gntdev_put_map(map);
+		return err;
+	}
+
 	if (copy_from_user(map->grants, &u->refs,
 			   sizeof(map->grants[0]) * op.count) != 0) {
-		gntdev_free_map(map);
+		gntdev_put_map(map);
 		return err;
 	}
 
@@ -461,13 +531,9 @@ static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv,
 	op.index = map->index << PAGE_SHIFT;
 	spin_unlock(&priv->lock);
 
-	if (copy_to_user(u, &op, sizeof(op)) != 0) {
-		spin_lock(&priv->lock);
-		gntdev_del_map(map);
-		spin_unlock(&priv->lock);
-		gntdev_free_map(map);
-		return err;
-	}
+	if (copy_to_user(u, &op, sizeof(op)) != 0)
+		return -EFAULT;
+
 	return 0;
 }
 
@@ -484,11 +550,12 @@ static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv,
 
 	spin_lock(&priv->lock);
 	map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count);
-	if (map)
-		err = gntdev_del_map(map);
+	if (map) {
+		list_del(&map->next);
+		gntdev_put_map(map);
+		err = 0;
+	}
 	spin_unlock(&priv->lock);
-	if (!err)
-		gntdev_free_map(map);
 	return err;
 }
 
@@ -496,43 +563,66 @@ static long gntdev_ioctl_get_offset_for_vaddr(struct gntdev_priv *priv,
 					      struct ioctl_gntdev_get_offset_for_vaddr __user *u)
 {
 	struct ioctl_gntdev_get_offset_for_vaddr op;
+	struct vm_area_struct *vma;
 	struct grant_map *map;
 
 	if (copy_from_user(&op, u, sizeof(op)) != 0)
 		return -EFAULT;
 	pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr);
 
-	spin_lock(&priv->lock);
-	map = gntdev_find_map_vaddr(priv, op.vaddr);
-	if (map == NULL ||
-	    map->vma->vm_start != op.vaddr) {
-		spin_unlock(&priv->lock);
+	vma = find_vma(current->mm, op.vaddr);
+	if (!vma || vma->vm_ops != &gntdev_vmops)
 		return -EINVAL;
-	}
+
+	map = vma->vm_private_data;
+	if (!map)
+		return -EINVAL;
+
 	op.offset = map->index << PAGE_SHIFT;
 	op.count = map->count;
-	spin_unlock(&priv->lock);
 
 	if (copy_to_user(u, &op, sizeof(op)) != 0)
 		return -EFAULT;
 	return 0;
 }
 
-static long gntdev_ioctl_set_max_grants(struct gntdev_priv *priv,
-					struct ioctl_gntdev_set_max_grants __user *u)
+static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u)
 {
-	struct ioctl_gntdev_set_max_grants op;
+	struct ioctl_gntdev_unmap_notify op;
+	struct grant_map *map;
+	int rc;
 
-	if (copy_from_user(&op, u, sizeof(op)) != 0)
+	if (copy_from_user(&op, u, sizeof(op)))
 		return -EFAULT;
-	pr_debug("priv %p, limit %d\n", priv, op.count);
-	if (op.count > limit)
-		return -E2BIG;
+
+	if (op.action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT))
+		return -EINVAL;
 
 	spin_lock(&priv->lock);
-	priv->limit = op.count;
+
+	list_for_each_entry(map, &priv->maps, next) {
+		uint64_t begin = map->index << PAGE_SHIFT;
+		uint64_t end = (map->index + map->count) << PAGE_SHIFT;
+		if (op.index >= begin && op.index < end)
+			goto found;
+	}
+	rc = -ENOENT;
+	goto unlock_out;
+
+ found:
+	if ((op.action & UNMAP_NOTIFY_CLEAR_BYTE) &&
+			(map->flags & GNTMAP_readonly)) {
+		rc = -EINVAL;
+		goto unlock_out;
+	}
+
+	map->notify.flags = op.action;
+	map->notify.addr = op.index - (map->index << PAGE_SHIFT);
+	map->notify.event = op.event_channel_port;
+	rc = 0;
+ unlock_out:
 	spin_unlock(&priv->lock);
-	return 0;
+	return rc;
 }
 
 static long gntdev_ioctl(struct file *flip,
@@ -551,8 +641,8 @@ static long gntdev_ioctl(struct file *flip,
 	case IOCTL_GNTDEV_GET_OFFSET_FOR_VADDR:
 		return gntdev_ioctl_get_offset_for_vaddr(priv, ptr);
 
-	case IOCTL_GNTDEV_SET_MAX_GRANTS:
-		return gntdev_ioctl_set_max_grants(priv, ptr);
+	case IOCTL_GNTDEV_SET_UNMAP_NOTIFY:
+		return gntdev_ioctl_notify(priv, ptr);
 
 	default:
 		pr_debug("priv %p, unknown cmd %x\n", priv, cmd);
@@ -568,7 +658,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
 	int index = vma->vm_pgoff;
 	int count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
 	struct grant_map *map;
-	int err = -EINVAL;
+	int i, err = -EINVAL;
 
 	if ((vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_SHARED))
 		return -EINVAL;
@@ -580,47 +670,70 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma)
 	map = gntdev_find_map_index(priv, index, count);
 	if (!map)
 		goto unlock_out;
-	if (map->vma)
+	if (use_ptemod && map->vma)
 		goto unlock_out;
-	if (priv->mm != vma->vm_mm) {
+	if (use_ptemod && priv->mm != vma->vm_mm) {
 		printk(KERN_WARNING "Huh? Other mm?\n");
 		goto unlock_out;
 	}
 
+	atomic_inc(&map->users);
+
 	vma->vm_ops = &gntdev_vmops;
 
 	vma->vm_flags |= VM_RESERVED|VM_DONTCOPY|VM_DONTEXPAND|VM_PFNMAP;
 
 	vma->vm_private_data = map;
-	map->vma = vma;
 
-	map->flags = GNTMAP_host_map | GNTMAP_application_map;
-	if (!(vma->vm_flags & VM_WRITE))
-		map->flags |= GNTMAP_readonly;
+	if (use_ptemod)
+		map->vma = vma;
+
+	if (map->flags) {
+		if ((vma->vm_flags & VM_WRITE) &&
+				(map->flags & GNTMAP_readonly))
+			return -EINVAL;
+	} else {
+		map->flags = GNTMAP_host_map;
+		if (!(vma->vm_flags & VM_WRITE))
+			map->flags |= GNTMAP_readonly;
+	}
 
 	spin_unlock(&priv->lock);
 
-	err = apply_to_page_range(vma->vm_mm, vma->vm_start,
-				  vma->vm_end - vma->vm_start,
-				  find_grant_ptes, map);
-	if (err) {
-		printk(KERN_WARNING "find_grant_ptes() failure.\n");
-		return err;
+	if (use_ptemod) {
+		err = apply_to_page_range(vma->vm_mm, vma->vm_start,
+					  vma->vm_end - vma->vm_start,
+					  find_grant_ptes, map);
+		if (err) {
+			printk(KERN_WARNING "find_grant_ptes() failure.\n");
+			goto out_put_map;
+		}
 	}
 
 	err = map_grant_pages(map);
-	if (err) {
-		printk(KERN_WARNING "map_grant_pages() failure.\n");
-		return err;
-	}
+	if (err)
+		goto out_put_map;
 
-	map->is_mapped = 1;
+	if (!use_ptemod) {
+		for (i = 0; i < count; i++) {
+			err = vm_insert_page(vma, vma->vm_start + i*PAGE_SIZE,
+				map->pages[i]);
+			if (err)
+				goto out_put_map;
+		}
+	}
 
 	return 0;
 
 unlock_out:
 	spin_unlock(&priv->lock);
 	return err;
+
+out_put_map:
+	if (use_ptemod)
+		map->vma = NULL;
+	gntdev_put_map(map);
+	return err;
 }
 
 static const struct file_operations gntdev_fops = {
@@ -646,6 +759,8 @@ static int __init gntdev_init(void)
 	if (!xen_domain())
 		return -ENODEV;
 
+	use_ptemod = xen_pv_domain();
+
 	err = misc_register(&gntdev_miscdev);
 	if (err != 0) {
 		printk(KERN_ERR "Could not register gntdev device\n");
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 9ef54ebc1194..9428ced04807 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -458,6 +458,9 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 	if (ret)
 		return ret;
 
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return ret;
+
 	for (i = 0; i < count; i++) {
 		/* m2p override only supported for GNTMAP_contains_pte mappings */
 		if (!(map_ops[i].flags & GNTMAP_contains_pte))
@@ -483,6 +486,9 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
 	if (ret)
 		return ret;
 
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return ret;
+
 	for (i = 0; i < count; i++) {
 		ret = m2p_remove_override(pages[i]);
 		if (ret)