Merge tag 'stable/for-linus-3.14-rc0-late-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen bugfixes from Konrad Rzeszutek Wilk:
 "Bug-fixes for the new features that were added during this cycle.

  There are also two fixes for long-standing issues for which we have a
  solution: grant-table operations extra work that was not needed
  causing performance issues and the self balloon code was too
  aggressive causing OOMs.

  Details:
   - Xen ARM couldn't use the new FIFO events
   - Xen ARM couldn't use the SWIOTLB if compiled as 32-bit with 64-bit PCIe devices.
   - Grant table were doing needless M2P operations.
   - Ratchet down the self-balloon code so it won't OOM.
   - Fix misplaced kfree in Xen PVH error code paths"

* tag 'stable/for-linus-3.14-rc0-late-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/pvh: Fix misplaced kfree from xlated_setup_gnttab_pages
  drivers: xen: deaggressive selfballoon driver
  xen/grant-table: Avoid m2p_override during mapping
  xen/gnttab: Use phys_addr_t to describe the grant frame base address
  xen: swiotlb: handle sizeof(dma_addr_t) != sizeof(phys_addr_t)
  arm/xen: Initialize event channels earlier

11 files changed, 197 insertions, 83 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index dc6ef9a2c649..e25419817791 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1905,6 +1905,7 @@ config XEN
 	depends on !GENERIC_ATOMIC64
 	select ARM_PSCI
 	select SWIOTLB_XEN
+	select ARCH_DMA_ADDR_T_64BIT
 	help
 	  Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
 
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 2162172c0ddc..b96723e258a0 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -23,6 +23,7 @@
 #include <linux/of_address.h>
 #include <linux/cpuidle.h>
 #include <linux/cpufreq.h>
+#include <linux/cpu.h>
 
 #include <linux/mm.h>
 
@@ -154,7 +155,7 @@ int xen_unmap_domain_mfn_range(struct vm_area_struct *vma,
 }
 EXPORT_SYMBOL_GPL(xen_unmap_domain_mfn_range);
 
-static void __init xen_percpu_init(void *unused)
+static void xen_percpu_init(void)
 {
 	struct vcpu_register_vcpu_info info;
 	struct vcpu_info *vcpup;
@@ -193,6 +194,31 @@ static void xen_power_off(void)
 		BUG();
 }
 
+static int xen_cpu_notification(struct notifier_block *self,
+				unsigned long action,
+				void *hcpu)
+{
+	switch (action) {
+	case CPU_STARTING:
+		xen_percpu_init();
+		break;
+	default:
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block xen_cpu_notifier = {
+	.notifier_call = xen_cpu_notification,
+};
+
+static irqreturn_t xen_arm_callback(int irq, void *arg)
+{
+	xen_hvm_evtchn_do_upcall();
+	return IRQ_HANDLED;
+}
+
 /*
  * see Documentation/devicetree/bindings/arm/xen.txt for the
  * documentation of the Xen Device Tree format.
@@ -208,7 +234,7 @@ static int __init xen_guest_init(void)
 	const char *version = NULL;
 	const char *xen_prefix = "xen,xen-";
 	struct resource res;
-	unsigned long grant_frames;
+	phys_addr_t grant_frames;
 
 	node = of_find_compatible_node(NULL, NULL, "xen,xen");
 	if (!node) {
@@ -227,8 +253,12 @@ static int __init xen_guest_init(void)
 		return 0;
 	grant_frames = res.start;
 	xen_events_irq = irq_of_parse_and_map(node, 0);
-	pr_info("Xen %s support found, events_irq=%d gnttab_frame_pfn=%lx\n",
-			version, xen_events_irq, (grant_frames >> PAGE_SHIFT));
+	pr_info("Xen %s support found, events_irq=%d gnttab_frame=%pa\n",
+			version, xen_events_irq, &grant_frames);
+
+	if (xen_events_irq < 0)
+		return -ENODEV;
+
 	xen_domain_type = XEN_HVM_DOMAIN;
 
 	xen_setup_features();
@@ -281,9 +311,21 @@ static int __init xen_guest_init(void)
 	disable_cpuidle();
 	disable_cpufreq();
 
+	xen_init_IRQ();
+
+	if (request_percpu_irq(xen_events_irq, xen_arm_callback,
+			       "events", &xen_vcpu)) {
+		pr_err("Error request IRQ %d\n", xen_events_irq);
+		return -EINVAL;
+	}
+
+	xen_percpu_init();
+
+	register_cpu_notifier(&xen_cpu_notifier);
+
 	return 0;
 }
-core_initcall(xen_guest_init);
+early_initcall(xen_guest_init);
 
 static int __init xen_pm_init(void)
 {
@@ -297,31 +339,6 @@ static int __init xen_pm_init(void)
 }
 late_initcall(xen_pm_init);
 
-static irqreturn_t xen_arm_callback(int irq, void *arg)
-{
-	xen_hvm_evtchn_do_upcall();
-	return IRQ_HANDLED;
-}
-
-static int __init xen_init_events(void)
-{
-	if (!xen_domain() || xen_events_irq < 0)
-		return -ENODEV;
-
-	xen_init_IRQ();
-
-	if (request_percpu_irq(xen_events_irq, xen_arm_callback,
-			"events", &xen_vcpu)) {
-		pr_err("Error requesting IRQ %d\n", xen_events_irq);
-		return -EINVAL;
-	}
-
-	on_each_cpu(xen_percpu_init, NULL, 0);
-
-	return 0;
-}
-postcore_initcall(xen_init_events);
-
 /* In the hypervisor.S file. */
 EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
 EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index 3e276eb23d1b..787e1bb5aafc 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -52,7 +52,8 @@ extern unsigned long set_phys_range_identity(unsigned long pfn_s,
 extern int m2p_add_override(unsigned long mfn, struct page *page,
 			    struct gnttab_map_grant_ref *kmap_op);
 extern int m2p_remove_override(struct page *page,
-				struct gnttab_map_grant_ref *kmap_op);
+			       struct gnttab_map_grant_ref *kmap_op,
+			       unsigned long mfn);
 extern struct page *m2p_find_override(unsigned long mfn);
 extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
 
@@ -121,7 +122,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
 		pfn = m2p_find_override_pfn(mfn, ~0);
 	}
 
-	/* 
+	/*
 	 * pfn is ~0 if there are no entries in the m2p for mfn or if the
 	 * entry doesn't map back to the mfn and m2p_override doesn't have a
 	 * valid entry for it.
diff --git a/arch/x86/xen/grant-table.c b/arch/x86/xen/grant-table.c
index 103c93f874b2..c98583588580 100644
--- a/arch/x86/xen/grant-table.c
+++ b/arch/x86/xen/grant-table.c
@@ -162,14 +162,15 @@ static int __init xlated_setup_gnttab_pages(void)
 	rc = arch_gnttab_map_shared(pfns, nr_grant_frames, nr_grant_frames,
 				    &xen_auto_xlat_grant_frames.vaddr);
 
-	kfree(pages);
 	if (rc) {
 		pr_warn("%s Couldn't map %ld pfns rc:%d\n", __func__,
 			nr_grant_frames, rc);
 		free_xenballooned_pages(nr_grant_frames, pages);
+		kfree(pages);
 		kfree(pfns);
 		return rc;
 	}
+	kfree(pages);
 
 	xen_auto_xlat_grant_frames.pfn = pfns;
 	xen_auto_xlat_grant_frames.count = nr_grant_frames;
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 696c694986d0..8009acbe41e4 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -899,13 +899,6 @@ int m2p_add_override(unsigned long mfn, struct page *page,
 					"m2p_add_override: pfn %lx not mapped", pfn))
 			return -EINVAL;
 	}
-	WARN_ON(PagePrivate(page));
-	SetPagePrivate(page);
-	set_page_private(page, mfn);
-	page->index = pfn_to_mfn(pfn);
-
-	if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn))))
-		return -ENOMEM;
 
 	if (kmap_op != NULL) {
 		if (!PageHighMem(page)) {
@@ -944,19 +937,16 @@ int m2p_add_override(unsigned long mfn, struct page *page,
 }
 EXPORT_SYMBOL_GPL(m2p_add_override);
 int m2p_remove_override(struct page *page,
-		struct gnttab_map_grant_ref *kmap_op)
+			struct gnttab_map_grant_ref *kmap_op,
+			unsigned long mfn)
 {
 	unsigned long flags;
-	unsigned long mfn;
 	unsigned long pfn;
 	unsigned long uninitialized_var(address);
 	unsigned level;
 	pte_t *ptep = NULL;
 
 	pfn = page_to_pfn(page);
-	mfn = get_phys_to_machine(pfn);
-	if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT))
-		return -EINVAL;
 
 	if (!PageHighMem(page)) {
 		address = (unsigned long)__va(pfn << PAGE_SHIFT);
@@ -970,10 +960,7 @@ int m2p_remove_override(struct page *page,
 	spin_lock_irqsave(&m2p_override_lock, flags);
 	list_del(&page->lru);
 	spin_unlock_irqrestore(&m2p_override_lock, flags);
-	WARN_ON(!PagePrivate(page));
-	ClearPagePrivate(page);
 
-	set_phys_to_machine(pfn, page->index);
 	if (kmap_op != NULL) {
 		if (!PageHighMem(page)) {
 			struct multicall_space mcs;
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 4b97b86da926..da18046d0e07 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -285,8 +285,7 @@ static void free_persistent_gnts(struct xen_blkif *blkif, struct rb_root *root,
 
 		if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST ||
 			!rb_next(&persistent_gnt->node)) {
-			ret = gnttab_unmap_refs(unmap, NULL, pages,
-				segs_to_unmap);
+			ret = gnttab_unmap_refs(unmap, pages, segs_to_unmap);
 			BUG_ON(ret);
 			put_free_pages(blkif, pages, segs_to_unmap);
 			segs_to_unmap = 0;
@@ -321,8 +320,7 @@ static void unmap_purged_grants(struct work_struct *work)
 		pages[segs_to_unmap] = persistent_gnt->page;
 
 		if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST) {
-			ret = gnttab_unmap_refs(unmap, NULL, pages,
-				segs_to_unmap);
+			ret = gnttab_unmap_refs(unmap, pages, segs_to_unmap);
 			BUG_ON(ret);
 			put_free_pages(blkif, pages, segs_to_unmap);
 			segs_to_unmap = 0;
@@ -330,7 +328,7 @@ static void unmap_purged_grants(struct work_struct *work)
 		kfree(persistent_gnt);
 	}
 	if (segs_to_unmap > 0) {
-		ret = gnttab_unmap_refs(unmap, NULL, pages, segs_to_unmap);
+		ret = gnttab_unmap_refs(unmap, pages, segs_to_unmap);
 		BUG_ON(ret);
 		put_free_pages(blkif, pages, segs_to_unmap);
 	}
@@ -670,15 +668,14 @@ static void xen_blkbk_unmap(struct xen_blkif *blkif,
 				    GNTMAP_host_map, pages[i]->handle);
 		pages[i]->handle = BLKBACK_INVALID_HANDLE;
 		if (++invcount == BLKIF_MAX_SEGMENTS_PER_REQUEST) {
-			ret = gnttab_unmap_refs(unmap, NULL, unmap_pages,
-			                        invcount);
+			ret = gnttab_unmap_refs(unmap, unmap_pages, invcount);
 			BUG_ON(ret);
 			put_free_pages(blkif, unmap_pages, invcount);
 			invcount = 0;
 		}
 	}
 	if (invcount) {
-		ret = gnttab_unmap_refs(unmap, NULL, unmap_pages, invcount);
+		ret = gnttab_unmap_refs(unmap, unmap_pages, invcount);
 		BUG_ON(ret);
 		put_free_pages(blkif, unmap_pages, invcount);
 	}
@@ -740,7 +737,7 @@ again:
 	}
 
 	if (segs_to_map) {
-		ret = gnttab_map_refs(map, NULL, pages_to_gnt, segs_to_map);
+		ret = gnttab_map_refs(map, pages_to_gnt, segs_to_map);
 		BUG_ON(ret);
 	}
 
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 073b4a19a8b0..34a2704fbc88 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -284,8 +284,10 @@ static int map_grant_pages(struct grant_map *map)
 	}
 
 	pr_debug("map %d+%d\n", map->index, map->count);
-	err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL,
-			map->pages, map->count);
+	err = gnttab_map_refs_userspace(map->map_ops,
+					use_ptemod ? map->kmap_ops : NULL,
+					map->pages,
+					map->count);
 	if (err)
 		return err;
 
@@ -315,9 +317,10 @@ static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
 		}
 	}
 
-	err = gnttab_unmap_refs(map->unmap_ops + offset,
-			use_ptemod ? map->kmap_ops + offset : NULL, map->pages + offset,
-			pages);
+	err = gnttab_unmap_refs_userspace(map->unmap_ops + offset,
+					  use_ptemod ? map->kmap_ops + offset : NULL,
+					  map->pages + offset,
+					  pages);
 	if (err)
 		return err;
 
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 1ce1c40331f3..8ee13e2e45e2 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -837,7 +837,7 @@ unsigned int gnttab_max_grant_frames(void)
 }
 EXPORT_SYMBOL_GPL(gnttab_max_grant_frames);
 
-int gnttab_setup_auto_xlat_frames(unsigned long addr)
+int gnttab_setup_auto_xlat_frames(phys_addr_t addr)
 {
 	xen_pfn_t *pfn;
 	unsigned int max_nr_gframes = __max_nr_grant_frames();
@@ -849,8 +849,8 @@ int gnttab_setup_auto_xlat_frames(unsigned long addr)
 
 	vaddr = xen_remap(addr, PAGE_SIZE * max_nr_gframes);
 	if (vaddr == NULL) {
-		pr_warn("Failed to ioremap gnttab share frames (addr=0x%08lx)!\n",
-			addr);
+		pr_warn("Failed to ioremap gnttab share frames (addr=%pa)!\n",
+			&addr);
 		return -ENOMEM;
 	}
 	pfn = kcalloc(max_nr_gframes, sizeof(pfn[0]), GFP_KERNEL);
@@ -928,15 +928,17 @@ void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count)
 }
 EXPORT_SYMBOL_GPL(gnttab_batch_copy);
 
-int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
+int __gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 		    struct gnttab_map_grant_ref *kmap_ops,
-		    struct page **pages, unsigned int count)
+		    struct page **pages, unsigned int count,
+		    bool m2p_override)
 {
 	int i, ret;
 	bool lazy = false;
 	pte_t *pte;
-	unsigned long mfn;
+	unsigned long mfn, pfn;
 
+	BUG_ON(kmap_ops && !m2p_override);
 	ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count);
 	if (ret)
 		return ret;
@@ -955,10 +957,12 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 			set_phys_to_machine(map_ops[i].host_addr >> PAGE_SHIFT,
 					map_ops[i].dev_bus_addr >> PAGE_SHIFT);
 		}
-		return ret;
+		return 0;
 	}
 
-	if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
+	if (m2p_override &&
+	    !in_interrupt() &&
+	    paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
 		arch_enter_lazy_mmu_mode();
 		lazy = true;
 	}
@@ -975,8 +979,20 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 		} else {
 			mfn = PFN_DOWN(map_ops[i].dev_bus_addr);
 		}
-		ret = m2p_add_override(mfn, pages[i], kmap_ops ?
-				       &kmap_ops[i] : NULL);
+		pfn = page_to_pfn(pages[i]);
+
+		WARN_ON(PagePrivate(pages[i]));
+		SetPagePrivate(pages[i]);
+		set_page_private(pages[i], mfn);
+
+		pages[i]->index = pfn_to_mfn(pfn);
+		if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		if (m2p_override)
+			ret = m2p_add_override(mfn, pages[i], kmap_ops ?
+					       &kmap_ops[i] : NULL);
 		if (ret)
 			goto out;
 	}
@@ -987,15 +1003,32 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 
 	return ret;
 }
+
+int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
+		    struct page **pages, unsigned int count)
+{
+	return __gnttab_map_refs(map_ops, NULL, pages, count, false);
+}
 EXPORT_SYMBOL_GPL(gnttab_map_refs);
 
-int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
+int gnttab_map_refs_userspace(struct gnttab_map_grant_ref *map_ops,
+			      struct gnttab_map_grant_ref *kmap_ops,
+			      struct page **pages, unsigned int count)
+{
+	return __gnttab_map_refs(map_ops, kmap_ops, pages, count, true);
+}
+EXPORT_SYMBOL_GPL(gnttab_map_refs_userspace);
+
+int __gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
 		      struct gnttab_map_grant_ref *kmap_ops,
-		      struct page **pages, unsigned int count)
+		      struct page **pages, unsigned int count,
+		      bool m2p_override)
 {
 	int i, ret;
 	bool lazy = false;
+	unsigned long pfn, mfn;
 
+	BUG_ON(kmap_ops && !m2p_override);
 	ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count);
 	if (ret)
 		return ret;
@@ -1006,17 +1039,33 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
 			set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT,
 					INVALID_P2M_ENTRY);
 		}
-		return ret;
+		return 0;
 	}
 
-	if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
+	if (m2p_override &&
+	    !in_interrupt() &&
+	    paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
 		arch_enter_lazy_mmu_mode();
 		lazy = true;
 	}
 
 	for (i = 0; i < count; i++) {
-		ret = m2p_remove_override(pages[i], kmap_ops ?
-				       &kmap_ops[i] : NULL);
+		pfn = page_to_pfn(pages[i]);
+		mfn = get_phys_to_machine(pfn);
+		if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		set_page_private(pages[i], INVALID_P2M_ENTRY);
+		WARN_ON(!PagePrivate(pages[i]));
+		ClearPagePrivate(pages[i]);
+		set_phys_to_machine(pfn, pages[i]->index);
+		if (m2p_override)
+			ret = m2p_remove_override(pages[i],
+						  kmap_ops ?
+						   &kmap_ops[i] : NULL,
+						  mfn);
 		if (ret)
 			goto out;
 	}
@@ -1027,8 +1076,22 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
 
 	return ret;
 }
+
+int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *map_ops,
+		    struct page **pages, unsigned int count)
+{
+	return __gnttab_unmap_refs(map_ops, NULL, pages, count, false);
+}
 EXPORT_SYMBOL_GPL(gnttab_unmap_refs);
 
+int gnttab_unmap_refs_userspace(struct gnttab_unmap_grant_ref *map_ops,
+				struct gnttab_map_grant_ref *kmap_ops,
+				struct page **pages, unsigned int count)
+{
+	return __gnttab_unmap_refs(map_ops, kmap_ops, pages, count, true);
+}
+EXPORT_SYMBOL_GPL(gnttab_unmap_refs_userspace);
+
 static unsigned nr_status_frames(unsigned nr_grant_frames)
 {
 	BUG_ON(grefs_per_grant_frame == 0);
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 1eac0731c349..ebd8f218a788 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -75,14 +75,32 @@ static unsigned long xen_io_tlb_nslabs;
 
 static u64 start_dma_addr;
 
+/*
+ * Both of these functions should avoid PFN_PHYS because phys_addr_t
+ * can be 32bit when dma_addr_t is 64bit leading to a loss in
+ * information if the shift is done before casting to 64bit.
+ */
 static inline dma_addr_t xen_phys_to_bus(phys_addr_t paddr)
 {
-	return phys_to_machine(XPADDR(paddr)).maddr;
+	unsigned long mfn = pfn_to_mfn(PFN_DOWN(paddr));
+	dma_addr_t dma = (dma_addr_t)mfn << PAGE_SHIFT;
+
+	dma |= paddr & ~PAGE_MASK;
+
+	return dma;
 }
 
 static inline phys_addr_t xen_bus_to_phys(dma_addr_t baddr)
 {
-	return machine_to_phys(XMADDR(baddr)).paddr;
+	unsigned long pfn = mfn_to_pfn(PFN_DOWN(baddr));
+	dma_addr_t dma = (dma_addr_t)pfn << PAGE_SHIFT;
+	phys_addr_t paddr = dma;
+
+	BUG_ON(paddr != dma); /* truncation has occurred, should never happen */
+
+	paddr |= baddr & ~PAGE_MASK;
+
+	return paddr;
 }
 
 static inline dma_addr_t xen_virt_to_bus(void *address)
diff --git a/drivers/xen/xen-selfballoon.c b/drivers/xen/xen-selfballoon.c
index 21e18c18c7a1..745ad79c1d8e 100644
--- a/drivers/xen/xen-selfballoon.c
+++ b/drivers/xen/xen-selfballoon.c
@@ -175,6 +175,7 @@ static void frontswap_selfshrink(void)
 #endif /* CONFIG_FRONTSWAP */
 
 #define MB2PAGES(mb)	((mb) << (20 - PAGE_SHIFT))
+#define PAGES2MB(pages) ((pages) >> (20 - PAGE_SHIFT))
 
 /*
  * Use current balloon size, the goal (vm_committed_as), and hysteresis
@@ -525,6 +526,7 @@ EXPORT_SYMBOL(register_xen_selfballooning);
 int xen_selfballoon_init(bool use_selfballooning, bool use_frontswap_selfshrink)
 {
 	bool enable = false;
+	unsigned long reserve_pages;
 
 	if (!xen_domain())
 		return -ENODEV;
@@ -549,6 +551,26 @@ int xen_selfballoon_init(bool use_selfballooning, bool use_frontswap_selfshrink)
 	if (!enable)
 		return -ENODEV;
 
+	/*
+	 * Give selfballoon_reserved_mb a default value(10% of total ram pages)
+	 * to make selfballoon not so aggressive.
+	 *
+	 * There are mainly two reasons:
+	 * 1) The original goal_page didn't consider some pages used by kernel
+	 *    space, like slab pages and memory used by device drivers.
+	 *
+	 * 2) The balloon driver may not give back memory to guest OS fast
+	 *    enough when the workload suddenly aquries a lot of physical memory.
+	 *
+	 * In both cases, the guest OS will suffer from memory pressure and
+	 * OOM killer may be triggered.
+	 * By reserving extra 10% of total ram pages, we can keep the system
+	 * much more reliably and response faster in some cases.
+	 */
+	if (!selfballoon_reserved_mb) {
+		reserve_pages = totalram_pages / 10;
+		selfballoon_reserved_mb = PAGES2MB(reserve_pages);
+	}
 	schedule_delayed_work(&selfballoon_worker, selfballoon_interval * HZ);
 
 	return 0;
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index 5acb1e4ac0d3..7ad033dbc845 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -185,17 +185,21 @@ struct grant_frames {
 };
 extern struct grant_frames xen_auto_xlat_grant_frames;
 unsigned int gnttab_max_grant_frames(void);
-int gnttab_setup_auto_xlat_frames(unsigned long addr);
+int gnttab_setup_auto_xlat_frames(phys_addr_t addr);
 void gnttab_free_auto_xlat_frames(void);
 
 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
 
 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
-		    struct gnttab_map_grant_ref *kmap_ops,
 		    struct page **pages, unsigned int count);
+int gnttab_map_refs_userspace(struct gnttab_map_grant_ref *map_ops,
+			      struct gnttab_map_grant_ref *kmap_ops,
+			      struct page **pages, unsigned int count);
 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
-		      struct gnttab_map_grant_ref *kunmap_ops,
 		      struct page **pages, unsigned int count);
+int gnttab_unmap_refs_userspace(struct gnttab_unmap_grant_ref *unmap_ops,
+				struct gnttab_map_grant_ref *kunmap_ops,
+				struct page **pages, unsigned int count);
 
 /* Perform a batch of grant map/copy operations. Retry every batch slot
  * for which the hypervisor returns GNTST_eagain. This is typically due