1 files changed, 292 insertions, 110 deletions

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index b4d4eac761d..eeba7544f0c 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -31,6 +31,8 @@
  * IN THE SOFTWARE.
  */
 
+#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
+
 #include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
@@ -38,6 +40,8 @@
 #include <linux/vmalloc.h>
 #include <linux/uaccess.h>
 #include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/hardirq.h>
 
 #include <xen/xen.h>
 #include <xen/interface/xen.h>
@@ -45,7 +49,9 @@
 #include <xen/grant_table.h>
 #include <xen/interface/memory.h>
 #include <xen/hvc-console.h>
+#include <xen/swiotlb-xen.h>
 #include <asm/xen/hypercall.h>
+#include <asm/xen/interface.h>
 
 #include <asm/pgtable.h>
 #include <asm/sync_bitops.h>
@@ -53,19 +59,13 @@
 /* External tools reserve first few grant table entries. */
 #define NR_RESERVED_ENTRIES 8
 #define GNTTAB_LIST_END 0xffffffff
-#define GREFS_PER_GRANT_FRAME \
-(grant_table_version == 1 ?                      \
-(PAGE_SIZE / sizeof(struct grant_entry_v1)) :   \
-(PAGE_SIZE / sizeof(union grant_entry_v2)))
 
 static grant_ref_t **gnttab_list;
 static unsigned int nr_grant_frames;
-static unsigned int boot_max_nr_grant_frames;
 static int gnttab_free_count;
 static grant_ref_t gnttab_free_head;
 static DEFINE_SPINLOCK(gnttab_list_lock);
-unsigned long xen_hvm_resume_frames;
-EXPORT_SYMBOL_GPL(xen_hvm_resume_frames);
+struct grant_frames xen_auto_xlat_grant_frames;
 
 static union {
 	struct grant_entry_v1 *v1;
@@ -81,7 +81,7 @@ struct gnttab_ops {
 	 * nr_gframes is the number of frames to map grant table. Returning
 	 * GNTST_okay means success and negative value means failure.
 	 */
-	int (*map_frames)(unsigned long *frames, unsigned int nr_gframes);
+	int (*map_frames)(xen_pfn_t *frames, unsigned int nr_gframes);
 	/*
 	 * Release a list of frames which are mapped in map_frames for grant
 	 * entry status.
@@ -151,6 +151,7 @@ static struct gnttab_ops *gnttab_interface;
 static grant_status_t *grstatus;
 
 static int grant_table_version;
+static int grefs_per_grant_frame;
 
 static struct gnttab_free_callback *gnttab_free_callback_list;
 
@@ -284,10 +285,9 @@ int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
 }
 EXPORT_SYMBOL_GPL(gnttab_grant_foreign_access);
 
-void gnttab_update_subpage_entry_v2(grant_ref_t ref, domid_t domid,
-				    unsigned long frame, int flags,
-				    unsigned page_off,
-				    unsigned length)
+static void gnttab_update_subpage_entry_v2(grant_ref_t ref, domid_t domid,
+					   unsigned long frame, int flags,
+					   unsigned page_off, unsigned length)
 {
 	gnttab_shared.v2[ref].sub_page.frame = frame;
 	gnttab_shared.v2[ref].sub_page.page_off = page_off;
@@ -344,9 +344,9 @@ bool gnttab_subpage_grants_available(void)
 }
 EXPORT_SYMBOL_GPL(gnttab_subpage_grants_available);
 
-void gnttab_update_trans_entry_v2(grant_ref_t ref, domid_t domid,
-				  int flags, domid_t trans_domid,
-				  grant_ref_t trans_gref)
+static void gnttab_update_trans_entry_v2(grant_ref_t ref, domid_t domid,
+					 int flags, domid_t trans_domid,
+					 grant_ref_t trans_gref)
 {
 	gnttab_shared.v2[ref].transitive.trans_domid = trans_domid;
 	gnttab_shared.v2[ref].transitive.gref = trans_gref;
@@ -426,10 +426,8 @@ static int gnttab_end_foreign_access_ref_v1(grant_ref_t ref, int readonly)
 	nflags = *pflags;
 	do {
 		flags = nflags;
-		if (flags & (GTF_reading|GTF_writing)) {
-			printk(KERN_ALERT "WARNING: g.e. still in use!\n");
+		if (flags & (GTF_reading|GTF_writing))
 			return 0;
-		}
 	} while ((nflags = sync_cmpxchg(pflags, flags, 0)) != flags);
 
 	return 1;
@@ -458,12 +456,102 @@ static int gnttab_end_foreign_access_ref_v2(grant_ref_t ref, int readonly)
 	return 1;
 }
 
-int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly)
+static inline int _gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly)
 {
 	return gnttab_interface->end_foreign_access_ref(ref, readonly);
 }
+
+int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly)
+{
+	if (_gnttab_end_foreign_access_ref(ref, readonly))
+		return 1;
+	pr_warn("WARNING: g.e. %#x still in use!\n", ref);
+	return 0;
+}
 EXPORT_SYMBOL_GPL(gnttab_end_foreign_access_ref);
 
+struct deferred_entry {
+	struct list_head list;
+	grant_ref_t ref;
+	bool ro;
+	uint16_t warn_delay;
+	struct page *page;
+};
+static LIST_HEAD(deferred_list);
+static void gnttab_handle_deferred(unsigned long);
+static DEFINE_TIMER(deferred_timer, gnttab_handle_deferred, 0, 0);
+
+static void gnttab_handle_deferred(unsigned long unused)
+{
+	unsigned int nr = 10;
+	struct deferred_entry *first = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&gnttab_list_lock, flags);
+	while (nr--) {
+		struct deferred_entry *entry
+			= list_first_entry(&deferred_list,
+					   struct deferred_entry, list);
+
+		if (entry == first)
+			break;
+		list_del(&entry->list);
+		spin_unlock_irqrestore(&gnttab_list_lock, flags);
+		if (_gnttab_end_foreign_access_ref(entry->ref, entry->ro)) {
+			put_free_entry(entry->ref);
+			if (entry->page) {
+				pr_debug("freeing g.e. %#x (pfn %#lx)\n",
+					 entry->ref, page_to_pfn(entry->page));
+				__free_page(entry->page);
+			} else
+				pr_info("freeing g.e. %#x\n", entry->ref);
+			kfree(entry);
+			entry = NULL;
+		} else {
+			if (!--entry->warn_delay)
+				pr_info("g.e. %#x still pending\n", entry->ref);
+			if (!first)
+				first = entry;
+		}
+		spin_lock_irqsave(&gnttab_list_lock, flags);
+		if (entry)
+			list_add_tail(&entry->list, &deferred_list);
+		else if (list_empty(&deferred_list))
+			break;
+	}
+	if (!list_empty(&deferred_list) && !timer_pending(&deferred_timer)) {
+		deferred_timer.expires = jiffies + HZ;
+		add_timer(&deferred_timer);
+	}
+	spin_unlock_irqrestore(&gnttab_list_lock, flags);
+}
+
+static void gnttab_add_deferred(grant_ref_t ref, bool readonly,
+				struct page *page)
+{
+	struct deferred_entry *entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
+	const char *what = KERN_WARNING "leaking";
+
+	if (entry) {
+		unsigned long flags;
+
+		entry->ref = ref;
+		entry->ro = readonly;
+		entry->page = page;
+		entry->warn_delay = 60;
+		spin_lock_irqsave(&gnttab_list_lock, flags);
+		list_add_tail(&entry->list, &deferred_list);
+		if (!timer_pending(&deferred_timer)) {
+			deferred_timer.expires = jiffies + HZ;
+			add_timer(&deferred_timer);
+		}
+		spin_unlock_irqrestore(&gnttab_list_lock, flags);
+		what = KERN_DEBUG "deferring";
+	}
+	printk("%s g.e. %#x (pfn %#lx)\n",
+	       what, ref, page ? page_to_pfn(page) : -1);
+}
+
 void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
 			       unsigned long page)
 {
@@ -471,12 +559,9 @@ void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
 		put_free_entry(ref);
 		if (page != 0)
 			free_page(page);
-	} else {
-		/* XXX This needs to be fixed so that the ref and page are
-		   placed on a list to be freed up later. */
-		printk(KERN_WARNING
-		       "WARNING: leaking g.e. and page still in use!\n");
-	}
+	} else
+		gnttab_add_deferred(ref, readonly,
+				    page ? virt_to_page(page) : NULL);
 }
 EXPORT_SYMBOL_GPL(gnttab_end_foreign_access);
 
@@ -644,9 +729,18 @@ void gnttab_request_free_callback(struct gnttab_free_callback *callback,
 				  void (*fn)(void *), void *arg, u16 count)
 {
 	unsigned long flags;
+	struct gnttab_free_callback *cb;
+
 	spin_lock_irqsave(&gnttab_list_lock, flags);
-	if (callback->next)
-		goto out;
+
+	/* Check if the callback is already on the list */
+	cb = gnttab_free_callback_list;
+	while (cb) {
+		if (cb == callback)
+			goto out;
+		cb = cb->next;
+	}
+
 	callback->fn = fn;
 	callback->arg = arg;
 	callback->count = count;
@@ -679,12 +773,14 @@ static int grow_gnttab_list(unsigned int more_frames)
 	unsigned int new_nr_grant_frames, extra_entries, i;
 	unsigned int nr_glist_frames, new_nr_glist_frames;
 
+	BUG_ON(grefs_per_grant_frame == 0);
+
 	new_nr_grant_frames = nr_grant_frames + more_frames;
-	extra_entries       = more_frames * GREFS_PER_GRANT_FRAME;
+	extra_entries       = more_frames * grefs_per_grant_frame;
 
-	nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP;
+	nr_glist_frames = (nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP;
 	new_nr_glist_frames =
-		(new_nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP;
+		(new_nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP;
 	for (i = nr_glist_frames; i < new_nr_glist_frames; i++) {
 		gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_ATOMIC);
 		if (!gnttab_list[i])
@@ -692,12 +788,12 @@ static int grow_gnttab_list(unsigned int more_frames)
 	}
 
 
-	for (i = GREFS_PER_GRANT_FRAME * nr_grant_frames;
-	     i < GREFS_PER_GRANT_FRAME * new_nr_grant_frames - 1; i++)
+	for (i = grefs_per_grant_frame * nr_grant_frames;
+	     i < grefs_per_grant_frame * new_nr_grant_frames - 1; i++)
 		gnttab_entry(i) = i + 1;
 
 	gnttab_entry(i) = gnttab_free_head;
-	gnttab_free_head = GREFS_PER_GRANT_FRAME * nr_grant_frames;
+	gnttab_free_head = grefs_per_grant_frame * nr_grant_frames;
 	gnttab_free_count += extra_entries;
 
 	nr_grant_frames = new_nr_grant_frames;
@@ -729,6 +825,11 @@ static unsigned int __max_nr_grant_frames(void)
 unsigned int gnttab_max_grant_frames(void)
 {
 	unsigned int xen_max = __max_nr_grant_frames();
+	static unsigned int boot_max_nr_grant_frames;
+
+	/* First time, initialize it properly. */
+	if (!boot_max_nr_grant_frames)
+		boot_max_nr_grant_frames = __max_nr_grant_frames();
 
 	if (xen_max > boot_max_nr_grant_frames)
 		return boot_max_nr_grant_frames;
@@ -736,71 +837,138 @@ unsigned int gnttab_max_grant_frames(void)
 }
 EXPORT_SYMBOL_GPL(gnttab_max_grant_frames);
 
+int gnttab_setup_auto_xlat_frames(phys_addr_t addr)
+{
+	xen_pfn_t *pfn;
+	unsigned int max_nr_gframes = __max_nr_grant_frames();
+	unsigned int i;
+	void *vaddr;
+
+	if (xen_auto_xlat_grant_frames.count)
+		return -EINVAL;
+
+	vaddr = xen_remap(addr, PAGE_SIZE * max_nr_gframes);
+	if (vaddr == NULL) {
+		pr_warn("Failed to ioremap gnttab share frames (addr=%pa)!\n",
+			&addr);
+		return -ENOMEM;
+	}
+	pfn = kcalloc(max_nr_gframes, sizeof(pfn[0]), GFP_KERNEL);
+	if (!pfn) {
+		xen_unmap(vaddr);
+		return -ENOMEM;
+	}
+	for (i = 0; i < max_nr_gframes; i++)
+		pfn[i] = PFN_DOWN(addr) + i;
+
+	xen_auto_xlat_grant_frames.vaddr = vaddr;
+	xen_auto_xlat_grant_frames.pfn = pfn;
+	xen_auto_xlat_grant_frames.count = max_nr_gframes;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(gnttab_setup_auto_xlat_frames);
+
+void gnttab_free_auto_xlat_frames(void)
+{
+	if (!xen_auto_xlat_grant_frames.count)
+		return;
+	kfree(xen_auto_xlat_grant_frames.pfn);
+	xen_unmap(xen_auto_xlat_grant_frames.vaddr);
+
+	xen_auto_xlat_grant_frames.pfn = NULL;
+	xen_auto_xlat_grant_frames.count = 0;
+	xen_auto_xlat_grant_frames.vaddr = NULL;
+}
+EXPORT_SYMBOL_GPL(gnttab_free_auto_xlat_frames);
+
+/* Handling of paged out grant targets (GNTST_eagain) */
+#define MAX_DELAY 256
+static inline void
+gnttab_retry_eagain_gop(unsigned int cmd, void *gop, int16_t *status,
+						const char *func)
+{
+	unsigned delay = 1;
+
+	do {
+		BUG_ON(HYPERVISOR_grant_table_op(cmd, gop, 1));
+		if (*status == GNTST_eagain)
+			msleep(delay++);
+	} while ((*status == GNTST_eagain) && (delay < MAX_DELAY));
+
+	if (delay >= MAX_DELAY) {
+		pr_err("%s: %s eagain grant\n", func, current->comm);
+		*status = GNTST_bad_page;
+	}
+}
+
+void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count)
+{
+	struct gnttab_map_grant_ref *op;
+
+	if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, batch, count))
+		BUG();
+	for (op = batch; op < batch + count; op++)
+		if (op->status == GNTST_eagain)
+			gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, op,
+						&op->status, __func__);
+}
+EXPORT_SYMBOL_GPL(gnttab_batch_map);
+
+void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count)
+{
+	struct gnttab_copy *op;
+
+	if (HYPERVISOR_grant_table_op(GNTTABOP_copy, batch, count))
+		BUG();
+	for (op = batch; op < batch + count; op++)
+		if (op->status == GNTST_eagain)
+			gnttab_retry_eagain_gop(GNTTABOP_copy, op,
+						&op->status, __func__);
+}
+EXPORT_SYMBOL_GPL(gnttab_batch_copy);
+
 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 i, ret;
-	pte_t *pte;
-	unsigned long mfn;
 
 	ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count);
 	if (ret)
 		return ret;
 
-	if (xen_feature(XENFEAT_auto_translated_physmap))
-		return ret;
-
-	for (i = 0; i < count; i++) {
-		/* Do not add to override if the map failed. */
-		if (map_ops[i].status)
-			continue;
+	/* Retry eagain maps */
+	for (i = 0; i < count; i++)
+		if (map_ops[i].status == GNTST_eagain)
+			gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i,
+						&map_ops[i].status, __func__);
 
-		if (map_ops[i].flags & GNTMAP_contains_pte) {
-			pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) +
-				(map_ops[i].host_addr & ~PAGE_MASK));
-			mfn = pte_mfn(*pte);
-		} else {
-			mfn = PFN_DOWN(map_ops[i].dev_bus_addr);
-		}
-		ret = m2p_add_override(mfn, pages[i], kmap_ops ?
-				       &kmap_ops[i] : NULL);
-		if (ret)
-			return ret;
-	}
-
-	return ret;
+	return set_foreign_p2m_mapping(map_ops, kmap_ops, pages, count);
 }
 EXPORT_SYMBOL_GPL(gnttab_map_refs);
 
 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
-		      struct page **pages, unsigned int count, bool clear_pte)
+		      struct gnttab_map_grant_ref *kmap_ops,
+		      struct page **pages, unsigned int count)
 {
-	int i, ret;
+	int ret;
 
 	ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count);
 	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], clear_pte);
-		if (ret)
-			return ret;
-	}
-
-	return ret;
+	return clear_foreign_p2m_mapping(unmap_ops, kmap_ops, pages, count);
 }
 EXPORT_SYMBOL_GPL(gnttab_unmap_refs);
 
 static unsigned nr_status_frames(unsigned nr_grant_frames)
 {
-	return (nr_grant_frames * GREFS_PER_GRANT_FRAME + SPP - 1) / SPP;
+	BUG_ON(grefs_per_grant_frame == 0);
+	return (nr_grant_frames * grefs_per_grant_frame + SPP - 1) / SPP;
 }
 
-static int gnttab_map_frames_v1(unsigned long *frames, unsigned int nr_gframes)
+static int gnttab_map_frames_v1(xen_pfn_t *frames, unsigned int nr_gframes)
 {
 	int rc;
 
@@ -817,7 +985,7 @@ static void gnttab_unmap_frames_v1(void)
 	arch_gnttab_unmap(gnttab_shared.addr, nr_grant_frames);
 }
 
-static int gnttab_map_frames_v2(unsigned long *frames, unsigned int nr_gframes)
+static int gnttab_map_frames_v2(xen_pfn_t *frames, unsigned int nr_gframes)
 {
 	uint64_t *sframes;
 	unsigned int nr_sframes;
@@ -869,14 +1037,15 @@ static void gnttab_unmap_frames_v2(void)
 static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
 {
 	struct gnttab_setup_table setup;
-	unsigned long *frames;
+	xen_pfn_t *frames;
 	unsigned int nr_gframes = end_idx + 1;
 	int rc;
 
-	if (xen_hvm_domain()) {
+	if (xen_feature(XENFEAT_auto_translated_physmap)) {
 		struct xen_add_to_physmap xatp;
 		unsigned int i = end_idx;
 		rc = 0;
+		BUG_ON(xen_auto_xlat_grant_frames.count < nr_gframes);
 		/*
 		 * Loop backwards, so that the first hypercall has the largest
 		 * index, ensuring that the table will grow only once.
@@ -885,11 +1054,11 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
 			xatp.domid = DOMID_SELF;
 			xatp.idx = i;
 			xatp.space = XENMAPSPACE_grant_table;
-			xatp.gpfn = (xen_hvm_resume_frames >> PAGE_SHIFT) + i;
+			xatp.gpfn = xen_auto_xlat_grant_frames.pfn[i];
 			rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
 			if (rc != 0) {
-				printk(KERN_WARNING
-						"grant table add_to_physmap failed, err=%d\n", rc);
+				pr_warn("grant table add_to_physmap failed, err=%d\n",
+					rc);
 				break;
 			}
 		} while (i-- > start_idx);
@@ -948,13 +1117,12 @@ static void gnttab_request_version(void)
 	int rc;
 	struct gnttab_set_version gsv;
 
-	if (xen_hvm_domain())
-		gsv.version = 1;
-	else
-		gsv.version = 2;
+	gsv.version = 1;
+
 	rc = HYPERVISOR_grant_table_op(GNTTABOP_set_version, &gsv, 1);
 	if (rc == 0 && gsv.version == 2) {
 		grant_table_version = 2;
+		grefs_per_grant_frame = PAGE_SIZE / sizeof(union grant_entry_v2);
 		gnttab_interface = &gnttab_v2_ops;
 	} else if (grant_table_version == 2) {
 		/*
@@ -967,42 +1135,41 @@ static void gnttab_request_version(void)
 		panic("we need grant tables version 2, but only version 1 is available");
 	} else {
 		grant_table_version = 1;
+		grefs_per_grant_frame = PAGE_SIZE / sizeof(struct grant_entry_v1);
 		gnttab_interface = &gnttab_v1_ops;
 	}
-	printk(KERN_INFO "Grant tables using version %d layout.\n",
-		grant_table_version);
+	pr_info("Grant tables using version %d layout\n", grant_table_version);
 }
 
-int gnttab_resume(void)
+static int gnttab_setup(void)
 {
 	unsigned int max_nr_gframes;
 
-	gnttab_request_version();
 	max_nr_gframes = gnttab_max_grant_frames();
 	if (max_nr_gframes < nr_grant_frames)
 		return -ENOSYS;
 
-	if (xen_pv_domain())
-		return gnttab_map(0, nr_grant_frames - 1);
-
-	if (gnttab_shared.addr == NULL) {
-		gnttab_shared.addr = ioremap(xen_hvm_resume_frames,
-						PAGE_SIZE * max_nr_gframes);
+	if (xen_feature(XENFEAT_auto_translated_physmap) && gnttab_shared.addr == NULL) {
+		gnttab_shared.addr = xen_auto_xlat_grant_frames.vaddr;
 		if (gnttab_shared.addr == NULL) {
-			printk(KERN_WARNING
-					"Failed to ioremap gnttab share frames!");
+			pr_warn("gnttab share frames (addr=0x%08lx) is not mapped!\n",
+				(unsigned long)xen_auto_xlat_grant_frames.vaddr);
 			return -ENOMEM;
 		}
 	}
+	return gnttab_map(0, nr_grant_frames - 1);
+}
 
-	gnttab_map(0, nr_grant_frames - 1);
-
-	return 0;
+int gnttab_resume(void)
+{
+	gnttab_request_version();
+	return gnttab_setup();
 }
 
 int gnttab_suspend(void)
 {
-	gnttab_interface->unmap_frames();
+	if (!xen_feature(XENFEAT_auto_translated_physmap))
+		gnttab_interface->unmap_frames();
 	return 0;
 }
 
@@ -1011,9 +1178,10 @@ static int gnttab_expand(unsigned int req_entries)
 	int rc;
 	unsigned int cur, extra;
 
+	BUG_ON(grefs_per_grant_frame == 0);
 	cur = nr_grant_frames;
-	extra = ((req_entries + (GREFS_PER_GRANT_FRAME-1)) /
-		 GREFS_PER_GRANT_FRAME);
+	extra = ((req_entries + (grefs_per_grant_frame-1)) /
+		 grefs_per_grant_frame);
 	if (cur + extra > gnttab_max_grant_frames())
 		return -ENOSPC;
 
@@ -1027,34 +1195,47 @@ static int gnttab_expand(unsigned int req_entries)
 int gnttab_init(void)
 {
 	int i;
+	unsigned long max_nr_grant_frames;
 	unsigned int max_nr_glist_frames, nr_glist_frames;
 	unsigned int nr_init_grefs;
+	int ret;
 
+	gnttab_request_version();
+	max_nr_grant_frames = gnttab_max_grant_frames();
 	nr_grant_frames = 1;
-	boot_max_nr_grant_frames = __max_nr_grant_frames();
 
 	/* Determine the maximum number of frames required for the
 	 * grant reference free list on the current hypervisor.
 	 */
-	max_nr_glist_frames = (boot_max_nr_grant_frames *
-			       GREFS_PER_GRANT_FRAME / RPP);
+	BUG_ON(grefs_per_grant_frame == 0);
+	max_nr_glist_frames = (max_nr_grant_frames *
+			       grefs_per_grant_frame / RPP);
 
 	gnttab_list = kmalloc(max_nr_glist_frames * sizeof(grant_ref_t *),
 			      GFP_KERNEL);
 	if (gnttab_list == NULL)
 		return -ENOMEM;
 
-	nr_glist_frames = (nr_grant_frames * GREFS_PER_GRANT_FRAME + RPP - 1) / RPP;
+	nr_glist_frames = (nr_grant_frames * grefs_per_grant_frame + RPP - 1) / RPP;
 	for (i = 0; i < nr_glist_frames; i++) {
 		gnttab_list[i] = (grant_ref_t *)__get_free_page(GFP_KERNEL);
-		if (gnttab_list[i] == NULL)
+		if (gnttab_list[i] == NULL) {
+			ret = -ENOMEM;
 			goto ini_nomem;
+		}
 	}
 
-	if (gnttab_resume() < 0)
-		return -ENODEV;
+	ret = arch_gnttab_init(max_nr_grant_frames,
+			       nr_status_frames(max_nr_grant_frames));
+	if (ret < 0)
+		goto ini_nomem;
+
+	if (gnttab_setup() < 0) {
+		ret = -ENODEV;
+		goto ini_nomem;
+	}
 
-	nr_init_grefs = nr_grant_frames * GREFS_PER_GRANT_FRAME;
+	nr_init_grefs = nr_grant_frames * grefs_per_grant_frame;
 
 	for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++)
 		gnttab_entry(i) = i + 1;
@@ -1070,11 +1251,11 @@ int gnttab_init(void)
 	for (i--; i >= 0; i--)
 		free_page((unsigned long)gnttab_list[i]);
 	kfree(gnttab_list);
-	return -ENOMEM;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(gnttab_init);
 
-static int __devinit __gnttab_init(void)
+static int __gnttab_init(void)
 {
 	/* Delay grant-table initialization in the PV on HVM case */
 	if (xen_hvm_domain())
@@ -1085,5 +1266,6 @@ static int __devinit __gnttab_init(void)
 
 	return gnttab_init();
 }
-
-core_initcall(__gnttab_init);
+/* Starts after core_initcall so that xen_pvh_gnttab_setup can be called
+ * beforehand to initialize xen_auto_xlat_grant_frames. */
+core_initcall_sync(__gnttab_init);