Merge branch 'stable/for-linus-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

* 'stable/for-linus-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: (37 commits)
  xen/pciback: Expand the warning message to include domain id.
  xen/pciback: Fix "device has been assigned to X domain!" warning
  xen/pciback: Move the PCI_DEV_FLAGS_ASSIGNED ops to the "[un|]bind"
  xen/xenbus: don't reimplement kvasprintf via a fixed size buffer
  xenbus: maximum buffer size is XENSTORE_PAYLOAD_MAX
  xen/xenbus: Reject replies with payload > XENSTORE_PAYLOAD_MAX.
  Xen: consolidate and simplify struct xenbus_driver instantiation
  xen-gntalloc: introduce missing kfree
  xen/xenbus: Fix compile error - missing header for xen_initial_domain()
  xen/netback: Enable netback on HVM guests
  xen/grant-table: Support mappings required by blkback
  xenbus: Use grant-table wrapper functions
  xenbus: Support HVM backends
  xen/xenbus-frontend: Fix compile error with randconfig
  xen/xenbus-frontend: Make error message more clear
  xen/privcmd: Remove unused support for arch specific privcmp mmap
  xen: Add xenbus_backend device
  xen: Add xenbus device driver
  xen: Add privcmd device driver
  xen/gntalloc: fix reference counts on multi-page mappings
  ...

44 files changed, 1513 insertions, 265 deletions

diff --git a/Documentation/ABI/stable/sysfs-bus-xen-backend b/Documentation/ABI/stable/sysfs-bus-xen-backend
new file mode 100644
index 000000000000..3d5951c8bf5f
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-bus-xen-backend
@@ -0,0 +1,75 @@
+What:		/sys/bus/xen-backend/devices/*/devtype
+Date:		Feb 2009
+KernelVersion:	2.6.38
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                The type of the device.  e.g., one of: 'vbd' (block),
+                'vif' (network), or 'vfb' (framebuffer).
+
+What:		/sys/bus/xen-backend/devices/*/nodename
+Date:		Feb 2009
+KernelVersion:	2.6.38
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                XenStore node (under /local/domain/NNN/) for this
+                backend device.
+
+What:		/sys/bus/xen-backend/devices/vbd-*/physical_device
+Date:		April 2011
+KernelVersion:	3.0
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                The major:minor number (in hexidecimal) of the
+                physical device providing the storage for this backend
+                block device.
+
+What:		/sys/bus/xen-backend/devices/vbd-*/mode
+Date:		April 2011
+KernelVersion:	3.0
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                Whether the block device is read-only ('r') or
+                read-write ('w').
+
+What:		/sys/bus/xen-backend/devices/vbd-*/statistics/f_req
+Date:		April 2011
+KernelVersion:	3.0
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                Number of flush requests from the frontend.
+
+What:		/sys/bus/xen-backend/devices/vbd-*/statistics/oo_req
+Date:		April 2011
+KernelVersion:	3.0
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                Number of requests delayed because the backend was too
+                busy processing previous requests.
+
+What:		/sys/bus/xen-backend/devices/vbd-*/statistics/rd_req
+Date:		April 2011
+KernelVersion:	3.0
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                Number of read requests from the frontend.
+
+What:		/sys/bus/xen-backend/devices/vbd-*/statistics/rd_sect
+Date:		April 2011
+KernelVersion:	3.0
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                Number of sectors read by the frontend.
+
+What:		/sys/bus/xen-backend/devices/vbd-*/statistics/wr_req
+Date:		April 2011
+KernelVersion:	3.0
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                Number of write requests from the frontend.
+
+What:		/sys/bus/xen-backend/devices/vbd-*/statistics/wr_sect
+Date:		April 2011
+KernelVersion:	3.0
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+                Number of sectors written by the frontend.
diff --git a/Documentation/ABI/stable/sysfs-devices-system-xen_memory b/Documentation/ABI/stable/sysfs-devices-system-xen_memory
new file mode 100644
index 000000000000..caa311d59ac1
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-devices-system-xen_memory
@@ -0,0 +1,77 @@
+What:		/sys/devices/system/xen_memory/xen_memory0/max_retry_count
+Date:		May 2011
+KernelVersion:	2.6.39
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+		The maximum number of times the balloon driver will
+		attempt to increase the balloon before giving up.  See
+		also 'retry_count' below.
+		A value of zero means retry forever and is the default one.
+
+What:		/sys/devices/system/xen_memory/xen_memory0/max_schedule_delay
+Date:		May 2011
+KernelVersion:	2.6.39
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+		The limit that 'schedule_delay' (see below) will be
+		increased to. The default value is 32 seconds.
+
+What:		/sys/devices/system/xen_memory/xen_memory0/retry_count
+Date:		May 2011
+KernelVersion:	2.6.39
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+		The current number of times that the balloon driver
+		has attempted to increase the size of the balloon.
+		The default value is one. With max_retry_count being
+		zero (unlimited), this means that the driver will attempt
+		to retry with a 'schedule_delay' delay.
+
+What:		/sys/devices/system/xen_memory/xen_memory0/schedule_delay
+Date:		May 2011
+KernelVersion:	2.6.39
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+		The time (in seconds) to wait between attempts to
+		increase the balloon.  Each time the balloon cannot be
+		increased, 'schedule_delay' is increased (until
+		'max_schedule_delay' is reached at which point it
+		will use the max value).
+
+What:		/sys/devices/system/xen_memory/xen_memory0/target
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+		The target number of pages to adjust this domain's
+		memory reservation to.
+
+What:		/sys/devices/system/xen_memory/xen_memory0/target_kb
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+		As target above, except the value is in KiB.
+
+What:		/sys/devices/system/xen_memory/xen_memory0/info/current_kb
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+		Current size (in KiB) of this domain's memory
+		reservation.
+
+What:		/sys/devices/system/xen_memory/xen_memory0/info/high_kb
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+		Amount (in KiB) of high memory in the balloon.
+
+What:		/sys/devices/system/xen_memory/xen_memory0/info/low_kb
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Description:
+		Amount (in KiB) of low (or normal) memory in the
+		balloon.
diff --git a/arch/ia64/include/asm/xen/interface.h b/arch/ia64/include/asm/xen/interface.h
index 1d2427d116e3..fbb519828aa1 100644
--- a/arch/ia64/include/asm/xen/interface.h
+++ b/arch/ia64/include/asm/xen/interface.h
@@ -71,7 +71,7 @@
 __DEFINE_GUEST_HANDLE(uchar, unsigned char);
 __DEFINE_GUEST_HANDLE(uint, unsigned int);
 __DEFINE_GUEST_HANDLE(ulong, unsigned long);
-__DEFINE_GUEST_HANDLE(u64, unsigned long);
+
 DEFINE_GUEST_HANDLE(char);
 DEFINE_GUEST_HANDLE(int);
 DEFINE_GUEST_HANDLE(long);
diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index 26c731a106af..fdce49c7aff6 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -29,7 +29,8 @@ config XEN_PVHVM
 
 config XEN_MAX_DOMAIN_MEMORY
        int
-       default 128
+       default 500 if X86_64
+       default 64 if X86_32
        depends on XEN
        help
          This only affects the sizing of some bss arrays, the unused
@@ -48,3 +49,4 @@ config XEN_DEBUG_FS
 	help
 	  Enable statistics output and various tuning options in debugfs.
 	  Enabling this option may incur a significant performance overhead.
+
diff --git a/arch/x86/xen/grant-table.c b/arch/x86/xen/grant-table.c
index 5a40d24ba331..3a5f55d51907 100644
--- a/arch/x86/xen/grant-table.c
+++ b/arch/x86/xen/grant-table.c
@@ -54,6 +54,20 @@ static int map_pte_fn(pte_t *pte, struct page *pmd_page,
 	return 0;
 }
 
+/*
+ * This function is used to map shared frames to store grant status. It is
+ * different from map_pte_fn above, the frames type here is uint64_t.
+ */
+static int map_pte_fn_status(pte_t *pte, struct page *pmd_page,
+			     unsigned long addr, void *data)
+{
+	uint64_t **frames = (uint64_t **)data;
+
+	set_pte_at(&init_mm, addr, pte, mfn_pte((*frames)[0], PAGE_KERNEL));
+	(*frames)++;
+	return 0;
+}
+
 static int unmap_pte_fn(pte_t *pte, struct page *pmd_page,
 			unsigned long addr, void *data)
 {
@@ -64,10 +78,10 @@ static int unmap_pte_fn(pte_t *pte, struct page *pmd_page,
 
 int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
 			   unsigned long max_nr_gframes,
-			   struct grant_entry **__shared)
+			   void **__shared)
 {
 	int rc;
-	struct grant_entry *shared = *__shared;
+	void *shared = *__shared;
 
 	if (shared == NULL) {
 		struct vm_struct *area =
@@ -83,8 +97,30 @@ int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
 	return rc;
 }
 
-void arch_gnttab_unmap_shared(struct grant_entry *shared,
-			      unsigned long nr_gframes)
+int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
+			   unsigned long max_nr_gframes,
+			   grant_status_t **__shared)
+{
+	int rc;
+	grant_status_t *shared = *__shared;
+
+	if (shared == NULL) {
+		/* No need to pass in PTE as we are going to do it
+		 * in apply_to_page_range anyhow. */
+		struct vm_struct *area =
+			alloc_vm_area(PAGE_SIZE * max_nr_gframes, NULL);
+		BUG_ON(area == NULL);
+		shared = area->addr;
+		*__shared = shared;
+	}
+
+	rc = apply_to_page_range(&init_mm, (unsigned long)shared,
+				 PAGE_SIZE * nr_gframes,
+				 map_pte_fn_status, &frames);
+	return rc;
+}
+
+void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
 {
 	apply_to_page_range(&init_mm, (unsigned long)shared,
 			    PAGE_SIZE * nr_gframes, unmap_pte_fn, NULL);
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 8069322e4c9e..37c794d31264 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -787,17 +787,14 @@ static const struct xenbus_device_id xen_blkbk_ids[] = {
 };
 
 
-static struct xenbus_driver xen_blkbk = {
-	.name = "vbd",
-	.owner = THIS_MODULE,
-	.ids = xen_blkbk_ids,
+static DEFINE_XENBUS_DRIVER(xen_blkbk, ,
 	.probe = xen_blkbk_probe,
 	.remove = xen_blkbk_remove,
 	.otherend_changed = frontend_changed
-};
+);
 
 
 int xen_blkif_xenbus_init(void)
 {
-	return xenbus_register_backend(&xen_blkbk);
+	return xenbus_register_backend(&xen_blkbk_driver);
 }
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 7b2ec5908413..9fd3ee203b1e 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1437,16 +1437,13 @@ static const struct xenbus_device_id blkfront_ids[] = {
 	{ "" }
 };
 
-static struct xenbus_driver blkfront = {
-	.name = "vbd",
-	.owner = THIS_MODULE,
-	.ids = blkfront_ids,
+static DEFINE_XENBUS_DRIVER(blkfront, ,
 	.probe = blkfront_probe,
 	.remove = blkfront_remove,
 	.resume = blkfront_resume,
 	.otherend_changed = blkback_changed,
 	.is_ready = blkfront_is_ready,
-};
+);
 
 static int __init xlblk_init(void)
 {
@@ -1461,7 +1458,7 @@ static int __init xlblk_init(void)
 		return -ENODEV;
 	}
 
-	ret = xenbus_register_frontend(&blkfront);
+	ret = xenbus_register_frontend(&blkfront_driver);
 	if (ret) {
 		unregister_blkdev(XENVBD_MAJOR, DEV_NAME);
 		return ret;
@@ -1474,7 +1471,7 @@ module_init(xlblk_init);
 
 static void __exit xlblk_exit(void)
 {
-	return xenbus_unregister_driver(&blkfront);
+	return xenbus_unregister_driver(&blkfront_driver);
 }
 module_exit(xlblk_exit);
 
diff --git a/drivers/input/misc/xen-kbdfront.c b/drivers/input/misc/xen-kbdfront.c
index ad2e51c04db8..02ca8680ea5b 100644
--- a/drivers/input/misc/xen-kbdfront.c
+++ b/drivers/input/misc/xen-kbdfront.c
@@ -361,15 +361,12 @@ static const struct xenbus_device_id xenkbd_ids[] = {
 	{ "" }
 };
 
-static struct xenbus_driver xenkbd_driver = {
-	.name = "vkbd",
-	.owner = THIS_MODULE,
-	.ids = xenkbd_ids,
+static DEFINE_XENBUS_DRIVER(xenkbd, ,
 	.probe = xenkbd_probe,
 	.remove = xenkbd_remove,
 	.resume = xenkbd_resume,
 	.otherend_changed = xenkbd_backend_changed,
-};
+);
 
 static int __init xenkbd_init(void)
 {
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 639cf8ab62ba..59effac15f36 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1634,7 +1634,7 @@ static int __init netback_init(void)
 	int rc = 0;
 	int group;
 
-	if (!xen_pv_domain())
+	if (!xen_domain())
 		return -ENODEV;
 
 	xen_netbk_group_nr = num_online_cpus();
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 1ce729d6af75..410018c4c528 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -474,17 +474,14 @@ static const struct xenbus_device_id netback_ids[] = {
 };
 
 
-static struct xenbus_driver netback = {
-	.name = "vif",
-	.owner = THIS_MODULE,
-	.ids = netback_ids,
+static DEFINE_XENBUS_DRIVER(netback, ,
 	.probe = netback_probe,
 	.remove = netback_remove,
 	.uevent = netback_uevent,
 	.otherend_changed = frontend_changed,
-};
+);
 
 int xenvif_xenbus_init(void)
 {
-	return xenbus_register_backend(&netback);
+	return xenbus_register_backend(&netback_driver);
 }
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 0a59c57864f5..fa679057630f 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1914,7 +1914,7 @@ static void xennet_sysfs_delif(struct net_device *netdev)
 
 #endif /* CONFIG_SYSFS */
 
-static struct xenbus_device_id netfront_ids[] = {
+static const struct xenbus_device_id netfront_ids[] = {
 	{ "vif" },
 	{ "" }
 };
@@ -1941,15 +1941,12 @@ static int __devexit xennet_remove(struct xenbus_device *dev)
 	return 0;
 }
 
-static struct xenbus_driver netfront_driver = {
-	.name = "vif",
-	.owner = THIS_MODULE,
-	.ids = netfront_ids,
+static DEFINE_XENBUS_DRIVER(netfront, ,
 	.probe = netfront_probe,
 	.remove = __devexit_p(xennet_remove),
 	.resume = netfront_resume,
 	.otherend_changed = netback_changed,
-};
+);
 
 static int __init netif_init(void)
 {
diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
index 90832a955991..7cf3d2fcf56a 100644
--- a/drivers/pci/xen-pcifront.c
+++ b/drivers/pci/xen-pcifront.c
@@ -1126,14 +1126,11 @@ static const struct xenbus_device_id xenpci_ids[] = {
 	{""},
 };
 
-static struct xenbus_driver xenbus_pcifront_driver = {
-	.name			= "pcifront",
-	.owner			= THIS_MODULE,
-	.ids			= xenpci_ids,
+static DEFINE_XENBUS_DRIVER(xenpci, "pcifront",
 	.probe			= pcifront_xenbus_probe,
 	.remove			= pcifront_xenbus_remove,
 	.otherend_changed	= pcifront_backend_changed,
-};
+);
 
 static int __init pcifront_init(void)
 {
@@ -1142,12 +1139,12 @@ static int __init pcifront_init(void)
 
 	pci_frontend_registrar(1 /* enable */);
 
-	return xenbus_register_frontend(&xenbus_pcifront_driver);
+	return xenbus_register_frontend(&xenpci_driver);
 }
 
 static void __exit pcifront_cleanup(void)
 {
-	xenbus_unregister_driver(&xenbus_pcifront_driver);
+	xenbus_unregister_driver(&xenpci_driver);
 	pci_frontend_registrar(0 /* disable */);
 }
 module_init(pcifront_init);
diff --git a/drivers/video/xen-fbfront.c b/drivers/video/xen-fbfront.c
index beac52fc1c0e..cb4529c40d74 100644
--- a/drivers/video/xen-fbfront.c
+++ b/drivers/video/xen-fbfront.c
@@ -671,20 +671,17 @@ InitWait:
 	}
 }
 
-static struct xenbus_device_id xenfb_ids[] = {
+static const struct xenbus_device_id xenfb_ids[] = {
 	{ "vfb" },
 	{ "" }
 };
 
-static struct xenbus_driver xenfb_driver = {
-	.name = "vfb",
-	.owner = THIS_MODULE,
-	.ids = xenfb_ids,
+static DEFINE_XENBUS_DRIVER(xenfb, ,
 	.probe = xenfb_probe,
 	.remove = xenfb_remove,
 	.resume = xenfb_resume,
 	.otherend_changed = xenfb_backend_changed,
-};
+);
 
 static int __init xenfb_init(void)
 {
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index 8795480c2350..a1ced521cf74 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -86,6 +86,7 @@ config XEN_BACKEND
 
 config XENFS
 	tristate "Xen filesystem"
+	select XEN_PRIVCMD
 	default y
 	help
 	  The xen filesystem provides a way for domains to share
@@ -171,4 +172,10 @@ config XEN_PCIDEV_BACKEND
 	  xen-pciback.hide=(03:00.0)(04:00.0)
 
 	  If in doubt, say m.
+
+config XEN_PRIVCMD
+	tristate
+	depends on XEN
+	default m
+
 endmenu
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
index 974fffdf22b2..aa31337192cc 100644
--- a/drivers/xen/Makefile
+++ b/drivers/xen/Makefile
@@ -19,7 +19,9 @@ obj-$(CONFIG_XEN_TMEM)			+= tmem.o
 obj-$(CONFIG_SWIOTLB_XEN)		+= swiotlb-xen.o
 obj-$(CONFIG_XEN_DOM0)			+= pci.o
 obj-$(CONFIG_XEN_PCIDEV_BACKEND)	+= xen-pciback/
+obj-$(CONFIG_XEN_PRIVCMD)		+= xen-privcmd.o
 
 xen-evtchn-y				:= evtchn.o
 xen-gntdev-y				:= gntdev.o
 xen-gntalloc-y				:= gntalloc.o
+xen-privcmd-y				:= privcmd.o
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 6e075cdd0c6b..e5e5812a1014 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -87,6 +87,7 @@ enum xen_irq_type {
  */
 struct irq_info {
 	struct list_head list;
+	int refcnt;
 	enum xen_irq_type type;	/* type */
 	unsigned irq;
 	unsigned short evtchn;	/* event channel */
@@ -406,6 +407,7 @@ static void xen_irq_init(unsigned irq)
 		panic("Unable to allocate metadata for IRQ%d\n", irq);
 
 	info->type = IRQT_UNBOUND;
+	info->refcnt = -1;
 
 	irq_set_handler_data(irq, info);
 
@@ -469,6 +471,8 @@ static void xen_free_irq(unsigned irq)
 
 	irq_set_handler_data(irq, NULL);
 
+	WARN_ON(info->refcnt > 0);
+
 	kfree(info);
 
 	/* Legacy IRQ descriptors are managed by the arch. */
@@ -637,7 +641,7 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 	if (irq != -1) {
 		printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n",
 		       irq, gsi);
-		goto out;	/* XXX need refcount? */
+		goto out;
 	}
 
 	irq = xen_allocate_irq_gsi(gsi);
@@ -939,9 +943,16 @@ static void unbind_from_irq(unsigned int irq)
 {
 	struct evtchn_close close;
 	int evtchn = evtchn_from_irq(irq);
+	struct irq_info *info = irq_get_handler_data(irq);
 
 	mutex_lock(&irq_mapping_update_lock);
 
+	if (info->refcnt > 0) {
+		info->refcnt--;
+		if (info->refcnt != 0)
+			goto done;
+	}
+
 	if (VALID_EVTCHN(evtchn)) {
 		close.port = evtchn;
 		if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
@@ -970,6 +981,7 @@ static void unbind_from_irq(unsigned int irq)
 
 	xen_free_irq(irq);
 
+ done:
 	mutex_unlock(&irq_mapping_update_lock);
 }
 
@@ -1065,6 +1077,69 @@ void unbind_from_irqhandler(unsigned int irq, void *dev_id)
 }
 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
 
+int evtchn_make_refcounted(unsigned int evtchn)
+{
+	int irq = evtchn_to_irq[evtchn];
+	struct irq_info *info;
+
+	if (irq == -1)
+		return -ENOENT;
+
+	info = irq_get_handler_data(irq);
+
+	if (!info)
+		return -ENOENT;
+
+	WARN_ON(info->refcnt != -1);
+
+	info->refcnt = 1;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
+
+int evtchn_get(unsigned int evtchn)
+{
+	int irq;
+	struct irq_info *info;
+	int err = -ENOENT;
+
+	if (evtchn >= NR_EVENT_CHANNELS)
+		return -EINVAL;
+
+	mutex_lock(&irq_mapping_update_lock);
+
+	irq = evtchn_to_irq[evtchn];
+	if (irq == -1)
+		goto done;
+
+	info = irq_get_handler_data(irq);
+
+	if (!info)
+		goto done;
+
+	err = -EINVAL;
+	if (info->refcnt <= 0)
+		goto done;
+
+	info->refcnt++;
+	err = 0;
+ done:
+	mutex_unlock(&irq_mapping_update_lock);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(evtchn_get);
+
+void evtchn_put(unsigned int evtchn)
+{
+	int irq = evtchn_to_irq[evtchn];
+	if (WARN_ON(irq == -1))
+		return;
+	unbind_from_irq(irq);
+}
+EXPORT_SYMBOL_GPL(evtchn_put);
+
 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
 {
 	int irq = per_cpu(ipi_to_irq, cpu)[vector];
diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index dbc13e94b612..b1f60a0c0bea 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -268,7 +268,7 @@ static int evtchn_bind_to_user(struct per_user_data *u, int port)
 	rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, IRQF_DISABLED,
 				       u->name, (void *)(unsigned long)port);
 	if (rc >= 0)
-		rc = 0;
+		rc = evtchn_make_refcounted(port);
 
 	return rc;
 }
diff --git a/drivers/xen/gntalloc.c b/drivers/xen/gntalloc.c
index e1c4c6e5b469..934985d14c24 100644
--- a/drivers/xen/gntalloc.c
+++ b/drivers/xen/gntalloc.c
@@ -74,7 +74,7 @@ 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 DEFINE_MUTEX(gref_mutex);
 static int gref_size;
 
 struct notify_info {
@@ -99,6 +99,12 @@ struct gntalloc_file_private_data {
 	uint64_t index;
 };
 
+struct gntalloc_vma_private_data {
+	struct gntalloc_gref *gref;
+	int users;
+	int count;
+};
+
 static void __del_gref(struct gntalloc_gref *gref);
 
 static void do_cleanup(void)
@@ -143,15 +149,15 @@ static int add_grefs(struct ioctl_gntalloc_alloc_gref *op,
 	}
 
 	/* Add to gref lists. */
-	spin_lock(&gref_lock);
+	mutex_lock(&gref_mutex);
 	list_splice_tail(&queue_gref, &gref_list);
 	list_splice_tail(&queue_file, &priv->list);
-	spin_unlock(&gref_lock);
+	mutex_unlock(&gref_mutex);
 
 	return 0;
 
 undo:
-	spin_lock(&gref_lock);
+	mutex_lock(&gref_mutex);
 	gref_size -= (op->count - i);
 
 	list_for_each_entry(gref, &queue_file, next_file) {
@@ -167,7 +173,7 @@ undo:
 	 */
 	if (unlikely(!list_empty(&queue_gref)))
 		list_splice_tail(&queue_gref, &gref_list);
-	spin_unlock(&gref_lock);
+	mutex_unlock(&gref_mutex);
 	return rc;
 }
 
@@ -178,8 +184,10 @@ static void __del_gref(struct gntalloc_gref *gref)
 		tmp[gref->notify.pgoff] = 0;
 		kunmap(gref->page);
 	}
-	if (gref->notify.flags & UNMAP_NOTIFY_SEND_EVENT)
+	if (gref->notify.flags & UNMAP_NOTIFY_SEND_EVENT) {
 		notify_remote_via_evtchn(gref->notify.event);
+		evtchn_put(gref->notify.event);
+	}