diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index 57aba6ba6f92df2162262ae9dd50a11fa527b49f..b54a3d20d6b2f3abca2ef9391cd3b426ab798497 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -65,13 +65,25 @@ extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn)
  *   bits (identity or foreign) are set.
  * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set
  *   identity or foreign indicator will be still set. __pfn_to_mfn() is
- *   encapsulating get_phys_to_machine().
- * - get_phys_to_machine() is to be called by __pfn_to_mfn() only to allow
- *   for future optimizations.
+ *   encapsulating get_phys_to_machine() which is called in special cases only.
+ * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special
+ *   cases needing an extended handling.
  */
 static inline unsigned long __pfn_to_mfn(unsigned long pfn)
 {
-	return get_phys_to_machine(pfn);
+	unsigned long mfn;
+
+	if (pfn < xen_p2m_size)
+		mfn = xen_p2m_addr[pfn];
+	else if (unlikely(pfn < xen_max_p2m_pfn))
+		return get_phys_to_machine(pfn);
+	else
+		return IDENTITY_FRAME(pfn);
+
+	if (unlikely(mfn == INVALID_P2M_ENTRY))
+		return get_phys_to_machine(pfn);
+
+	return mfn;
 }
 
 static inline unsigned long pfn_to_mfn(unsigned long pfn)
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 3e3f8f8c3a301624885761358b1406e8f5122de6..6ab6150c8560d5b1d11d3ce8fcc8c2673a652d30 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1158,20 +1158,16 @@ static void __init xen_cleanhighmap(unsigned long vaddr,
 	 * instead of somewhere later and be confusing. */
 	xen_mc_flush();
 }
-static void __init xen_pagetable_p2m_copy(void)
+
+static void __init xen_pagetable_p2m_free(void)
 {
 	unsigned long size;
 	unsigned long addr;
-	unsigned long new_mfn_list;
-
-	if (xen_feature(XENFEAT_auto_translated_physmap))
-		return;
 
 	size = PAGE_ALIGN(xen_start_info->nr_pages * sizeof(unsigned long));
 
-	new_mfn_list = xen_revector_p2m_tree();
 	/* No memory or already called. */
-	if (!new_mfn_list || new_mfn_list == xen_start_info->mfn_list)
+	if ((unsigned long)xen_p2m_addr == xen_start_info->mfn_list)
 		return;
 
 	/* using __ka address and sticking INVALID_P2M_ENTRY! */
@@ -1189,8 +1185,6 @@ static void __init xen_pagetable_p2m_copy(void)
 
 	size = PAGE_ALIGN(xen_start_info->nr_pages * sizeof(unsigned long));
 	memblock_free(__pa(xen_start_info->mfn_list), size);
-	/* And revector! Bye bye old array */
-	xen_start_info->mfn_list = new_mfn_list;
 
 	/* At this stage, cleanup_highmap has already cleaned __ka space
 	 * from _brk_limit way up to the max_pfn_mapped (which is the end of
@@ -1214,14 +1208,26 @@ static void __init xen_pagetable_p2m_copy(void)
 }
 #endif
 
-static void __init xen_pagetable_init(void)
+static void __init xen_pagetable_p2m_setup(void)
 {
-	paging_init();
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return;
+
+	xen_vmalloc_p2m_tree();
+
 #ifdef CONFIG_X86_64
-	xen_pagetable_p2m_copy();
-#else
-	xen_revector_p2m_tree();
+	xen_pagetable_p2m_free();
 #endif
+	/* And revector! Bye bye old array */
+	xen_start_info->mfn_list = (unsigned long)xen_p2m_addr;
+}
+
+static void __init xen_pagetable_init(void)
+{
+	paging_init();
+
+	xen_pagetable_p2m_setup();
+
 	/* Allocate and initialize top and mid mfn levels for p2m structure */
 	xen_build_mfn_list_list();
 
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 8c3d8fbbba935d9f03a8a12e1abff19b21a193d1..7d844739e513b02b8b53d099069adec92722a4a2 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -3,21 +3,22 @@
  * guests themselves, but it must also access and update the p2m array
  * during suspend/resume when all the pages are reallocated.
  *
- * The p2m table is logically a flat array, but we implement it as a
- * three-level tree to allow the address space to be sparse.
+ * The logical flat p2m table is mapped to a linear kernel memory area.
+ * For accesses by Xen a three-level tree linked via mfns only is set up to
+ * allow the address space to be sparse.
  *
- *                               Xen
- *                                |
- *     p2m_top              p2m_top_mfn
- *       /  \                   /   \
- * p2m_mid p2m_mid	p2m_mid_mfn p2m_mid_mfn
- *    / \      / \         /           /
- *  p2m p2m p2m p2m p2m p2m p2m ...
+ *               Xen
+ *                |
+ *          p2m_top_mfn
+ *              /   \
+ * p2m_mid_mfn p2m_mid_mfn
+ *         /           /
+ *  p2m p2m p2m ...
  *
  * The p2m_mid_mfn pages are mapped by p2m_top_mfn_p.
  *
- * The p2m_top and p2m_top_mfn levels are limited to 1 page, so the
- * maximum representable pseudo-physical address space is:
+ * The p2m_top_mfn level is limited to 1 page, so the maximum representable
+ * pseudo-physical address space is:
  *  P2M_TOP_PER_PAGE * P2M_MID_PER_PAGE * P2M_PER_PAGE pages
  *
  * P2M_PER_PAGE depends on the architecture, as a mfn is always
@@ -30,6 +31,9 @@
  * leaf entries, or for the top  root, or middle one, for which there is a void
  * entry, we assume it is  "missing". So (for example)
  *  pfn_to_mfn(0x90909090)=INVALID_P2M_ENTRY.
+ * We have a dedicated page p2m_missing with all entries being
+ * INVALID_P2M_ENTRY. This page may be referenced multiple times in the p2m
+ * list/tree in case there are multiple areas with P2M_PER_PAGE invalid pfns.
  *
  * We also have the possibility of setting 1-1 mappings on certain regions, so
  * that:
@@ -39,122 +43,20 @@
  * PCI BARs, or ACPI spaces), we can create mappings easily because we
  * get the PFN value to match the MFN.
  *
- * For this to work efficiently we have one new page p2m_identity and
- * allocate (via reserved_brk) any other pages we need to cover the sides
- * (1GB or 4MB boundary violations). All entries in p2m_identity are set to
- * INVALID_P2M_ENTRY type (Xen toolstack only recognizes that and MFNs,
- * no other fancy value).
+ * For this to work efficiently we have one new page p2m_identity. All entries
+ * in p2m_identity are set to INVALID_P2M_ENTRY type (Xen toolstack only
+ * recognizes that and MFNs, no other fancy value).
  *
  * On lookup we spot that the entry points to p2m_identity and return the
  * identity value instead of dereferencing and returning INVALID_P2M_ENTRY.
  * If the entry points to an allocated page, we just proceed as before and
- * return the PFN.  If the PFN has IDENTITY_FRAME_BIT set we unmask that in
+ * return the PFN. If the PFN has IDENTITY_FRAME_BIT set we unmask that in
  * appropriate functions (pfn_to_mfn).
  *
  * The reason for having the IDENTITY_FRAME_BIT instead of just returning the
  * PFN is that we could find ourselves where pfn_to_mfn(pfn)==pfn for a
  * non-identity pfn. To protect ourselves against we elect to set (and get) the
  * IDENTITY_FRAME_BIT on all identity mapped PFNs.
- *
- * This simplistic diagram is used to explain the more subtle piece of code.
- * There is also a digram of the P2M at the end that can help.
- * Imagine your E820 looking as so:
- *
- *                    1GB                                           2GB    4GB
- * /-------------------+---------\/----\         /----------\    /---+-----\
- * | System RAM        | Sys RAM ||ACPI|         | reserved |    | Sys RAM |
- * \-------------------+---------/\----/         \----------/    \---+-----/
- *                               ^- 1029MB                       ^- 2001MB
- *
- * [1029MB = 263424 (0x40500), 2001MB = 512256 (0x7D100),
- *  2048MB = 524288 (0x80000)]
- *
- * And dom0_mem=max:3GB,1GB is passed in to the guest, meaning memory past 1GB
- * is actually not present (would have to kick the balloon driver to put it in).
- *
- * When we are told to set the PFNs for identity mapping (see patch: "xen/setup:
- * Set identity mapping for non-RAM E820 and E820 gaps.") we pass in the start
- * of the PFN and the end PFN (263424 and 512256 respectively). The first step
- * is to reserve_brk a top leaf page if the p2m[1] is missing. The top leaf page
- * covers 512^2 of page estate (1GB) and in case the start or end PFN is not
- * aligned on 512^2*PAGE_SIZE (1GB) we reserve_brk new middle and leaf pages as
- * required to split any existing p2m_mid_missing middle pages.
- *
- * With the E820 example above, 263424 is not 1GB aligned so we allocate a
- * reserve_brk page which will cover the PFNs estate from 0x40000 to 0x80000.
- * Each entry in the allocate page is "missing" (points to p2m_missing).
- *
- * Next stage is to determine if we need to do a more granular boundary check
- * on the 4MB (or 2MB depending on architecture) off the start and end pfn's.
- * We check if the start pfn and end pfn violate that boundary check, and if
- * so reserve_brk a (p2m[x][y]) leaf page. This way we have a much finer
- * granularity of setting which PFNs are missing and which ones are identity.
- * In our example 263424 and 512256 both fail the check so we reserve_brk two
- * pages. Populate them with INVALID_P2M_ENTRY (so they both have "missing"
- * values) and assign them to p2m[1][2] and p2m[1][488] respectively.
- *
- * At this point we would at minimum reserve_brk one page, but could be up to
- * three. Each call to set_phys_range_identity has at maximum a three page
- * cost. If we were to query the P2M at this stage, all those entries from
- * start PFN through end PFN (so 1029MB -> 2001MB) would return
- * INVALID_P2M_ENTRY ("missing").
- *
- * The next step is to walk from the start pfn to the end pfn setting
- * the IDENTITY_FRAME_BIT on each PFN. This is done in set_phys_range_identity.
- * If we find that the middle entry is pointing to p2m_missing we can swap it
- * over to p2m_identity - this way covering 4MB (or 2MB) PFN space (and
- * similarly swapping p2m_mid_missing for p2m_mid_identity for larger regions).
- * At this point we do not need to worry about boundary aligment (so no need to
- * reserve_brk a middle page, figure out which PFNs are "missing" and which
- * ones are identity), as that has been done earlier.  If we find that the
- * middle leaf is not occupied by p2m_identity or p2m_missing, we dereference
- * that page (which covers 512 PFNs) and set the appropriate PFN with
- * IDENTITY_FRAME_BIT. In our example 263424 and 512256 end up there, and we
- * set from p2m[1][2][256->511] and p2m[1][488][0->256] with
- * IDENTITY_FRAME_BIT set.
- *
- * All other regions that are void (or not filled) either point to p2m_missing
- * (considered missing) or have the default value of INVALID_P2M_ENTRY (also
- * considered missing). In our case, p2m[1][2][0->255] and p2m[1][488][257->511]
- * contain the INVALID_P2M_ENTRY value and are considered "missing."
- *
- * Finally, the region beyond the end of of the E820 (4 GB in this example)
- * is set to be identity (in case there are MMIO regions placed here).
- *
- * This is what the p2m ends up looking (for the E820 above) with this
- * fabulous drawing:
- *
- *    p2m         /--------------\
- *  /-----\       | &mfn_list[0],|                           /-----------------\
- *  |  0  |------>| &mfn_list[1],|    /---------------\      | ~0, ~0, ..      |
- *  |-----|       |  ..., ~0, ~0 |    | ~0, ~0, [x]---+----->| IDENTITY [@256] |
- *  |  1  |---\   \--------------/    | [p2m_identity]+\     | IDENTITY [@257] |
- *  |-----|    \                      | [p2m_identity]+\\    | ....            |
- *  |  2  |--\  \-------------------->|  ...          | \\   \----------------/
- *  |-----|   \                       \---------------/  \\
- *  |  3  |-\  \                                          \\  p2m_identity [1]
- *  |-----|  \  \-------------------->/---------------\   /-----------------\
- *  | ..  |\  |                       | [p2m_identity]+-->| ~0, ~0, ~0, ... |
- *  \-----/ | |                       | [p2m_identity]+-->| ..., ~0         |
- *          | |                       | ....          |   \-----------------/
- *          | |                       +-[x], ~0, ~0.. +\
- *          | |                       \---------------/ \
- *          | |                                          \-> /---------------\
- *          | V  p2m_mid_missing       p2m_missing           | IDENTITY[@0]  |
- *          | /-----------------\     /------------\         | IDENTITY[@256]|
- *          | | [p2m_missing]   +---->| ~0, ~0, ...|         | ~0, ~0, ....  |
- *          | | [p2m_missing]   +---->| ..., ~0    |         \---------------/
- *          | | ...             |     \------------/
- *          | \-----------------/
- *          |
- *          |     p2m_mid_identity
- *          |   /-----------------\
- *          \-->| [p2m_identity]  +---->[1]
- *              | [p2m_identity]  +---->[1]
- *              | ...             |
- *              \-----------------/
- *
- * where ~0 is INVALID_P2M_ENTRY. IDENTITY is (PFN | IDENTITY_BIT)
  */
 
 #include <linux/init.h>
@@ -179,6 +81,8 @@
 #include "multicalls.h"
 #include "xen-ops.h"
 
+#define PMDS_PER_MID_PAGE	(P2M_MID_PER_PAGE / PTRS_PER_PTE)
+
 static void __init m2p_override_init(void);
 
 unsigned long *xen_p2m_addr __read_mostly;
@@ -188,22 +92,15 @@ EXPORT_SYMBOL_GPL(xen_p2m_size);
 unsigned long xen_max_p2m_pfn __read_mostly;
 EXPORT_SYMBOL_GPL(xen_max_p2m_pfn);
 
+static DEFINE_SPINLOCK(p2m_update_lock);
+
 static unsigned long *p2m_mid_missing_mfn;
 static unsigned long *p2m_top_mfn;
 static unsigned long **p2m_top_mfn_p;
-
-/* Placeholders for holes in the address space */
-static RESERVE_BRK_ARRAY(unsigned long, p2m_missing, P2M_PER_PAGE);
-static RESERVE_BRK_ARRAY(unsigned long *, p2m_mid_missing, P2M_MID_PER_PAGE);
-
-static RESERVE_BRK_ARRAY(unsigned long **, p2m_top, P2M_TOP_PER_PAGE);
-
-static RESERVE_BRK_ARRAY(unsigned long, p2m_identity, P2M_PER_PAGE);
-static RESERVE_BRK_ARRAY(unsigned long *, p2m_mid_identity, P2M_MID_PER_PAGE);
-
-RESERVE_BRK(p2m_mid, PAGE_SIZE * (MAX_DOMAIN_PAGES / (P2M_PER_PAGE * P2M_MID_PER_PAGE)));
-
-static int use_brk = 1;
+static unsigned long *p2m_missing;
+static unsigned long *p2m_identity;
+static pte_t *p2m_missing_pte;
+static pte_t *p2m_identity_pte;
 
 static inline unsigned p2m_top_index(unsigned long pfn)
 {
@@ -221,14 +118,6 @@ static inline unsigned p2m_index(unsigned long pfn)
 	return pfn % P2M_PER_PAGE;
 }
 
-static void p2m_top_init(unsigned long ***top)
-{
-	unsigned i;
-
-	for (i = 0; i < P2M_TOP_PER_PAGE; i++)
-		top[i] = p2m_mid_missing;
-}
-
 static void p2m_top_mfn_init(unsigned long *top)
 {
 	unsigned i;
@@ -245,35 +134,32 @@ static void p2m_top_mfn_p_init(unsigned long **top)
 		top[i] = p2m_mid_missing_mfn;
 }
 
-static void p2m_mid_init(unsigned long **mid, unsigned long *leaf)
+static void p2m_mid_mfn_init(unsigned long *mid, unsigned long *leaf)
 {
 	unsigned i;
 
 	for (i = 0; i < P2M_MID_PER_PAGE; i++)
-		mid[i] = leaf;
+		mid[i] = virt_to_mfn(leaf);
 }
 
-static void p2m_mid_mfn_init(unsigned long *mid, unsigned long *leaf)
+static void p2m_init(unsigned long *p2m)
 {
 	unsigned i;
 
-	for (i = 0; i < P2M_MID_PER_PAGE; i++)
-		mid[i] = virt_to_mfn(leaf);
+	for (i = 0; i < P2M_PER_PAGE; i++)
+		p2m[i] = INVALID_P2M_ENTRY;
 }
 
-static void p2m_init(unsigned long *p2m)
+static void p2m_init_identity(unsigned long *p2m, unsigned long pfn)
 {
 	unsigned i;
 
-	for (i = 0; i < P2M_MID_PER_PAGE; i++)
-		p2m[i] = INVALID_P2M_ENTRY;
+	for (i = 0; i < P2M_PER_PAGE; i++)
+		p2m[i] = IDENTITY_FRAME(pfn + i);
 }
 
 static void * __ref alloc_p2m_page(void)
 {
-	if (unlikely(use_brk))
-		return extend_brk(PAGE_SIZE, PAGE_SIZE);
-
 	if (unlikely(!slab_is_available()))
 		return alloc_bootmem_align(PAGE_SIZE, PAGE_SIZE);
 
@@ -299,7 +185,10 @@ static void free_p2m_page(void *p)
  */
 void __ref xen_build_mfn_list_list(void)
 {
-	unsigned long pfn;
+	unsigned long pfn, mfn;
+	pte_t *ptep;
+	unsigned int level, topidx, mididx;
+	unsigned long *mid_mfn_p;
 
 	if (xen_feature(XENFEAT_auto_translated_physmap))
 		return;
@@ -319,20 +208,23 @@ void __ref xen_build_mfn_list_list(void)
 		p2m_mid_mfn_init(p2m_mid_missing_mfn, p2m_missing);
 	}
 
-	for (pfn = 0; pfn < xen_max_p2m_pfn; pfn += P2M_PER_PAGE) {
-		unsigned topidx = p2m_top_index(pfn);
-		unsigned mididx = p2m_mid_index(pfn);
-		unsigned long **mid;
-		unsigned long *mid_mfn_p;
+	for (pfn = 0; pfn < xen_max_p2m_pfn && pfn < MAX_P2M_PFN;
+	     pfn += P2M_PER_PAGE) {
+		topidx = p2m_top_index(pfn);
+		mididx = p2m_mid_index(pfn);
 
-		mid = p2m_top[topidx];
 		mid_mfn_p = p2m_top_mfn_p[topidx];
+		ptep = lookup_address((unsigned long)(xen_p2m_addr + pfn),
+				      &level);
+		BUG_ON(!ptep || level != PG_LEVEL_4K);
+		mfn = pte_mfn(*ptep);
+		ptep = (pte_t *)((unsigned long)ptep & ~(PAGE_SIZE - 1));
 
 		/* Don't bother allocating any mfn mid levels if
 		 * they're just missing, just update the stored mfn,
 		 * since all could have changed over a migrate.
 		 */
-		if (mid == p2m_mid_missing) {
+		if (ptep == p2m_missing_pte || ptep == p2m_identity_pte) {
 			BUG_ON(mididx);
 			BUG_ON(mid_mfn_p != p2m_mid_missing_mfn);
 			p2m_top_mfn[topidx] = virt_to_mfn(p2m_mid_missing_mfn);
@@ -341,11 +233,6 @@ void __ref xen_build_mfn_list_list(void)
 		}
 
 		if (mid_mfn_p == p2m_mid_missing_mfn) {
-			/*
-			 * XXX boot-time only!  We should never find
-			 * missing parts of the mfn tree after
-			 * runtime.
-			 */
 			mid_mfn_p = alloc_p2m_page();
 			p2m_mid_mfn_init(mid_mfn_p, p2m_missing);
 
@@ -353,7 +240,7 @@ void __ref xen_build_mfn_list_list(void)
 		}
 
 		p2m_top_mfn[topidx] = virt_to_mfn(mid_mfn_p);
-		mid_mfn_p[mididx] = virt_to_mfn(mid[mididx]);
+		mid_mfn_p[mididx] = mfn;
 	}
 }
 
@@ -372,154 +259,153 @@ void xen_setup_mfn_list_list(void)
 /* Set up p2m_top to point to the domain-builder provided p2m pages */
 void __init xen_build_dynamic_phys_to_machine(void)
 {
-	unsigned long *mfn_list;
-	unsigned long max_pfn;
 	unsigned long pfn;
 
 	 if (xen_feature(XENFEAT_auto_translated_physmap))
 		return;
 
 	xen_p2m_addr = (unsigned long *)xen_start_info->mfn_list;
-	mfn_list = (unsigned long *)xen_start_info->mfn_list;
-	max_pfn = min(MAX_DOMAIN_PAGES, xen_start_info->nr_pages);
-	xen_max_p2m_pfn = max_pfn;
-	xen_p2m_size = max_pfn;
+	xen_p2m_size = ALIGN(xen_start_info->nr_pages, P2M_PER_PAGE);
 
-	p2m_missing = alloc_p2m_page();
-	p2m_init(p2m_missing);
-	p2m_identity = alloc_p2m_page();
-	p2m_init(p2m_identity);
+	for (pfn = xen_start_info->nr_pages; pfn < xen_p2m_size; pfn++)
+		xen_p2m_addr[pfn] = INVALID_P2M_ENTRY;
 
-	p2m_mid_missing = alloc_p2m_page();
-	p2m_mid_init(p2m_mid_missing, p2m_missing);
-	p2m_mid_identity = alloc_p2m_page();
-	p2m_mid_init(p2m_mid_identity, p2m_identity);
+	xen_max_p2m_pfn = xen_p2m_size;
+}
 
-	p2m_top = alloc_p2m_page();
-	p2m_top_init(p2m_top);
+#define P2M_TYPE_IDENTITY	0
+#define P2M_TYPE_MISSING	1
+#define P2M_TYPE_PFN		2
+#define P2M_TYPE_UNKNOWN	3
 
-	/*
-	 * The domain builder gives us a pre-constructed p2m array in
-	 * mfn_list for all the pages initially given to us, so we just
-	 * need to graft that into our tree structure.
-	 */
-	for (pfn = 0; pfn < max_pfn; pfn += P2M_PER_PAGE) {
-		unsigned topidx = p2m_top_index(pfn);
-		unsigned mididx = p2m_mid_index(pfn);
+static int xen_p2m_elem_type(unsigned long pfn)
+{
+	unsigned long mfn;
 
-		if (p2m_top[topidx] == p2m_mid_missing) {
-			unsigned long **mid = alloc_p2m_page();
-			p2m_mid_init(mid, p2m_missing);
+	if (pfn >= xen_p2m_size)
+		return P2M_TYPE_IDENTITY;
 
-			p2m_top[topidx] = mid;
-		}
+	mfn = xen_p2m_addr[pfn];
 
-		/*
-		 * As long as the mfn_list has enough entries to completely
-		 * fill a p2m page, pointing into the array is ok. But if
-		 * not the entries beyond the last pfn will be undefined.
-		 */
-		if (unlikely(pfn + P2M_PER_PAGE > max_pfn)) {
-			unsigned long p2midx;
+	if (mfn == INVALID_P2M_ENTRY)
+		return P2M_TYPE_MISSING;
 
-			p2midx = max_pfn % P2M_PER_PAGE;
-			for ( ; p2midx < P2M_PER_PAGE; p2midx++)
-				mfn_list[pfn + p2midx] = INVALID_P2M_ENTRY;
-		}
-		p2m_top[topidx][mididx] = &mfn_list[pfn];
-	}
+	if (mfn & IDENTITY_FRAME_BIT)
+		return P2M_TYPE_IDENTITY;
+
+	return P2M_TYPE_PFN;
 }
-#ifdef CONFIG_X86_64
-unsigned long __init xen_revector_p2m_tree(void)
+
+static void __init xen_rebuild_p2m_list(unsigned long *p2m)
 {
-	unsigned long va_start;
-	unsigned long va_end;
+	unsigned int i, chunk;
 	unsigned long pfn;
-	unsigned long pfn_free = 0;
-	unsigned long *mfn_list = NULL;
-	unsigned long size;
-
-	use_brk = 0;
-	va_start = xen_start_info->mfn_list;
-	/*We copy in increments of P2M_PER_PAGE * sizeof(unsigned long),
-	 * so make sure it is rounded up to that */
-	size = PAGE_ALIGN(xen_start_info->nr_pages * sizeof(unsigned long));
-	va_end = va_start + size;
-
-	/* If we were revectored already, don't do it again. */
-	if (va_start <= __START_KERNEL_map && va_start >= __PAGE_OFFSET)
-		return 0;
-
-	mfn_list = alloc_bootmem_align(size, PAGE_SIZE);
-	if (!mfn_list) {
-		pr_warn("Could not allocate space for a new P2M tree!\n");
-		return xen_start_info->mfn_list;
-	}
-	/* Fill it out with INVALID_P2M_ENTRY value */
-	memset(mfn_list, 0xFF, size);
+	unsigned long *mfns;
+	pte_t *ptep;
+	pmd_t *pmdp;
+	int type;
 
-	for (pfn = 0; pfn < ALIGN(MAX_DOMAIN_PAGES, P2M_PER_PAGE); pfn += P2M_PER_PAGE) {
-		unsigned topidx = p2m_top_index(pfn);
-		unsigned mididx;
-		unsigned long *mid_p;
-
-		if (!p2m_top[topidx])
-			continue;
+	p2m_missing = alloc_p2m_page();
+	p2m_init(p2m_missing);
+	p2m_identity = alloc_p2m_page();
+	p2m_init(p2m_identity);
 
-		if (p2m_top[topidx] == p2m_mid_missing)
-			continue;
+	p2m_missing_pte = alloc_p2m_page();
+	paravirt_alloc_pte(&init_mm, __pa(p2m_missing_pte) >> PAGE_SHIFT);
+	p2m_identity_pte = alloc_p2m_page();
+	paravirt_alloc_pte(&init_mm, __pa(p2m_identity_pte) >> PAGE_SHIFT);
+	for (i = 0; i < PTRS_PER_PTE; i++) {
+		set_pte(p2m_missing_pte + i,
+			pfn_pte(PFN_DOWN(__pa(p2m_missing)), PAGE_KERNEL));
+		set_pte(p2m_identity_pte + i,
+			pfn_pte(PFN_DOWN(__pa(p2m_identity)), PAGE_KERNEL));
+	}
 
-		mididx = p2m_mid_index(pfn);
-		mid_p = p2m_top[topidx][mididx];
-		if (!mid_p)
-			continue;
-		if ((mid_p == p2m_missing) || (mid_p == p2m_identity))
+	for (pfn = 0; pfn < xen_max_p2m_pfn; pfn += chunk) {
+		/*
+		 * Try to map missing/identity PMDs or p2m-pages if possible.
+		 * We have to respect the structure of the mfn_list_list
+		 * which will be built just afterwards.
+		 * Chunk size to test is one p2m page if we are in the middle
+		 * of a mfn_list_list mid page and the complete mid page area
+		 * if we are at index 0 of the mid page. Please note that a
+		 * mid page might cover more than one PMD, e.g. on 32 bit PAE
+		 * kernels.
+		 */
+		chunk = (pfn & (P2M_PER_PAGE * P2M_MID_PER_PAGE - 1)) ?
+			P2M_PER_PAGE : P2M_PER_PAGE * P2M_MID_PER_PAGE;
+
+		type = xen_p2m_elem_type(pfn);
+		i = 0;
+		if (type != P2M_TYPE_PFN)
+			for (i = 1; i < chunk; i++)
+				if (xen_p2m_elem_type(pfn + i) != type)
+					break;
+		if (i < chunk)
+			/* Reset to minimal chunk size. */
+			chunk = P2M_PER_PAGE;
+
+		if (type == P2M_TYPE_PFN || i < chunk) {
+			/* Use initial p2m page contents. */
+#ifdef CONFIG_X86_64
+			mfns = alloc_p2m_page();
+			copy_page(mfns, xen_p2m_addr + pfn);
+#else
+			mfns = xen_p2m_addr + pfn;
+#endif
+			ptep = populate_extra_pte((unsigned long)(p2m + pfn));
+			set_pte(ptep,
+				pfn_pte(PFN_DOWN(__pa(mfns)), PAGE_KERNEL));
 			continue;
+		}
 
-		if ((unsigned long)mid_p == INVALID_P2M_ENTRY)
+		if (chunk == P2M_PER_PAGE) {
+			/* Map complete missing or identity p2m-page. */
+			mfns = (type == P2M_TYPE_MISSING) ?
+				p2m_missing : p2m_identity;
+			ptep = populate_extra_pte((unsigned long)(p2m + pfn));
+			set_pte(ptep,
+				pfn_pte(PFN_DOWN(__pa(mfns)), PAGE_KERNEL));
 			continue;
+		}
 
-		/* The old va. Rebase it on mfn_list */
-		if (mid_p >= (unsigned long *)va_start && mid_p <= (unsigned long *)va_end) {
-			unsigned long *new;
+		/* Complete missing or identity PMD(s) can be mapped. */
+		ptep = (type == P2M_TYPE_MISSING) ?
+			p2m_missing_pte : p2m_identity_pte;
+		for (i = 0; i < PMDS_PER_MID_PAGE; i++) {
+			pmdp = populate_extra_pmd(
+				(unsigned long)(p2m + pfn + i * PTRS_PER_PTE));
+			set_pmd(pmdp, __pmd(__pa(ptep) | _KERNPG_TABLE));
+		}
+	}
+}
 
-			if (pfn_free  > (size / sizeof(unsigned long))) {
-				WARN(1, "Only allocated for %ld pages, but we want %ld!\n",
-				     size / sizeof(unsigned long), pfn_free);
-				return 0;
-			}
-			new = &mfn_list[pfn_free];
+void __init xen_vmalloc_p2m_tree(void)
+{
+	static struct vm_struct vm;
 
-			copy_page(new, mid_p);
-			p2m_top[topidx][mididx] = &mfn_list[pfn_free];
+	vm.flags = VM_ALLOC;
+	vm.size = ALIGN(sizeof(unsigned long) * xen_max_p2m_pfn,
+			PMD_SIZE * PMDS_PER_MID_PAGE);
+	vm_area_register_early(&vm, PMD_SIZE * PMDS_PER_MID_PAGE);
+	pr_notice("p2m virtual area at %p, size is %lx\n", vm.addr, vm.size);
 
-			pfn_free += P2M_PER_PAGE;
+	xen_max_p2m_pfn = vm.size / sizeof(unsigned long);
 
-		}
-		/* This should be the leafs allocated for identity from _brk. */
-	}
+	xen_rebuild_p2m_list(vm.addr);
 
+	xen_p2m_addr = vm.addr;
 	xen_p2m_size = xen_max_p2m_pfn;
-	xen_p2m_addr = mfn_list;
 
 	xen_inv_extra_mem();
 
 	m2p_override_init();
-	return (unsigned long)mfn_list;
 }
-#else
-unsigned long __init xen_revector_p2m_tree(void)
-{
-	use_brk = 0;
-	xen_p2m_size = xen_max_p2m_pfn;
-	xen_inv_extra_mem();
-	m2p_override_init();
-	return 0;
-}
-#endif
+
 unsigned long get_phys_to_machine(unsigned long pfn)
 {
-	unsigned topidx, mididx, idx;
+	pte_t *ptep;
+	unsigned int level;
 
 	if (unlikely(pfn >= xen_p2m_size)) {
 		if (pfn < xen_max_p2m_pfn)
@@ -528,22 +414,82 @@ unsigned long get_phys_to_machine(unsigned long pfn)
 		return IDENTITY_FRAME(pfn);
 	}
 
-	topidx = p2m_top_index(pfn);
-	mididx = p2m_mid_index(pfn);
-	idx = p2m_index(pfn);
+	ptep = lookup_address((unsigned long)(xen_p2m_addr + pfn), &level);
+	BUG_ON(!ptep || level != PG_LEVEL_4K);
 
 	/*
 	 * The INVALID_P2M_ENTRY is filled in both p2m_*identity
 	 * and in p2m_*missing, so returning the INVALID_P2M_ENTRY
 	 * would be wrong.
 	 */
-	if (p2m_top[topidx][mididx] == p2m_identity)
+	if (pte_pfn(*ptep) == PFN_DOWN(__pa(p2m_identity)))
 		return IDENTITY_FRAME(pfn);
 
-	return p2m_top[topidx][mididx][idx];
+	return xen_p2m_addr[pfn];
 }
 EXPORT_SYMBOL_GPL(get_phys_to_machine);
 
+/*
+ * Allocate new pmd(s). It is checked whether the old pmd is still in place.
+ * If not, nothing is changed. This is okay as the only reason for allocating
+ * a new pmd is to replace p2m_missing_pte or p2m_identity_pte by a individual
+ * pmd. In case of PAE/x86-32 there are multiple pmds to allocate!
+ */
+static pte_t *alloc_p2m_pmd(unsigned long addr, pte_t *ptep, pte_t *pte_pg)
+{
+	pte_t *ptechk;
+	pte_t *pteret = ptep;
+	pte_t *pte_newpg[PMDS_PER_MID_PAGE];
+	pmd_t *pmdp;
+	unsigned int level;
+	unsigned long flags;
+	unsigned long vaddr;
+	int i;
+
+	/* Do all allocations first to bail out in error case. */
+	for (i = 0; i < PMDS_PER_MID_PAGE; i++) {
+		pte_newpg[i] = alloc_p2m_page();
+		if (!pte_newpg[i]) {
+			for (i--; i >= 0; i--)
+				free_p2m_page(pte_newpg[i]);
+
+			return NULL;
+		}
+	}
+
+	vaddr = addr & ~(PMD_SIZE * PMDS_PER_MID_PAGE - 1);
+
+	for (i = 0; i < PMDS_PER_MID_PAGE; i++) {
+		copy_page(pte_newpg[i], pte_pg);
+		paravirt_alloc_pte(&init_mm, __pa(pte_newpg[i]) >> PAGE_SHIFT);
+
+		pmdp = lookup_pmd_address(vaddr);
+		BUG_ON(!pmdp);
+
+		spin_lock_irqsave(&p2m_update_lock, flags);
+
+		ptechk = lookup_address(vaddr, &level);
+		if (ptechk == pte_pg) {
+			set_pmd(pmdp,
+				__pmd(__pa(pte_newpg[i]) | _KERNPG_TABLE));
+			if (vaddr == (addr & ~(PMD_SIZE - 1)))
+				pteret = pte_offset_kernel(pmdp, addr);
+			pte_newpg[i] = NULL;
+		}
+
+		spin_unlock_irqrestore(&p2m_update_lock, flags);
+
+		if (pte_newpg[i]) {
+			paravirt_release_pte(__pa(pte_newpg[i]) >> PAGE_SHIFT);
+			free_p2m_page(pte_newpg[i]);
+		}
+
+		vaddr += PMD_SIZE;
+	}
+
+	return pteret;
+}
+
 /*
  * Fully allocate the p2m structure for a given pfn.  We need to check
  * that both the top and mid levels are allocated, and make sure the
@@ -554,58 +500,62 @@ EXPORT_SYMBOL_GPL(get_phys_to_machine);
 static bool alloc_p2m(unsigned long pfn)
 {
 	unsigned topidx, mididx;
-	unsigned long ***top_p, **mid;
 	unsigned long *top_mfn_p, *mid_mfn;
-	unsigned long *p2m_orig;
+	pte_t *ptep, *pte_pg;
+	unsigned int level;
+	unsigned long flags;
+	unsigned long addr = (unsigned long)(xen_p2m_addr + pfn);
+	unsigned long p2m_pfn;
 
 	topidx = p2m_top_index(pfn);
 	mididx = p2m_mid_index(pfn);
 
-	top_p = &p2m_top[topidx];
-	mid = ACCESS_ONCE(*top_p);
+	ptep = lookup_address(addr, &level);
+	BUG_ON(!ptep || level != PG_LEVEL_4K);
+	pte_pg = (pte_t *)((unsigned long)ptep & ~(PAGE_SIZE - 1));
 
-	if (mid == p2m_mid_missing) {
-		/* Mid level is missing, allocate a new one */
-		mid = alloc_p2m_page();
-		if (!mid)
+	if (pte_pg == p2m_missing_pte || pte_pg == p2m_identity_pte) {
+		/* PMD level is missing, allocate a new one */
+		ptep = alloc_p2m_pmd(addr, ptep, pte_pg);
+		if (!ptep)
 			return false;
-
-		p2m_mid_init(mid, p2m_missing);
-
-		if (cmpxchg(top_p, p2m_mid_missing, mid) != p2m_mid_missing)
-			free_p2m_page(mid);
 	}
 
-	top_mfn_p = &p2m_top_mfn[topidx];
-	mid_mfn = ACCESS_ONCE(p2m_top_mfn_p[topidx]);
+	if (p2m_top_mfn) {
+		top_mfn_p = &p2m_top_mfn[topidx];
+		mid_mfn = ACCESS_ONCE(p2m_top_mfn_p[topidx]);
 
-	BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p);
+		BUG_ON(virt_to_mfn(mid_mfn) != *top_mfn_p);
 
-	if (mid_mfn == p2m_mid_missing_mfn) {
-		/* Separately check the mid mfn level */
-		unsigned long missing_mfn;
-		unsigned long mid_mfn_mfn;
-		unsigned long old_mfn;
+		if (mid_mfn == p2m_mid_missing_mfn) {
+			/* Separately check the mid mfn level */
+			unsigned long missing_mfn;
+			unsigned long mid_mfn_mfn;
+			unsigned long old_mfn;
 
-		mid_mfn = alloc_p2m_page();
-		if (!mid_mfn)
-			return false;
+			mid_mfn = alloc_p2m_page();
+			if (!mid_mfn)
+				return false;
 
-		p2m_mid_mfn_init(mid_mfn, p2m_missing);
+			p2m_mid_mfn_init(mid_mfn, p2m_missing);
 
-		missing_mfn = virt_to_mfn(p2m_mid_missing_mfn);
-		mid_mfn_mfn = virt_to_mfn(mid_mfn);
-		old_mfn = cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn);
-		if (old_mfn != missing_mfn) {
-			free_p2m_page(mid_mfn);
-			mid_mfn = mfn_to_virt(old_mfn);
-		} else {
-			p2m_top_mfn_p[topidx] = mid_mfn;
+			missing_mfn = virt_to_mfn(p2m_mid_missing_mfn);
+			mid_mfn_mfn = virt_to_mfn(mid_mfn);
+			old_mfn = cmpxchg(top_mfn_p, missing_mfn, mid_mfn_mfn);
+			if (old_mfn != missing_mfn) {
+				free_p2m_page(mid_mfn);
+				mid_mfn = mfn_to_virt(old_mfn);
+			} else {
+				p2m_top_mfn_p[topidx] = mid_mfn;
+			}
 		}
+	} else {
+		mid_mfn = NULL;
 	}
 
-	p2m_orig = ACCESS_ONCE(p2m_top[topidx][mididx]);
-	if (p2m_orig == p2m_identity || p2m_orig == p2m_missing) {
+	p2m_pfn = pte_pfn(ACCESS_ONCE(*ptep));
+	if (p2m_pfn == PFN_DOWN(__pa(p2m_identity)) ||
+	    p2m_pfn == PFN_DOWN(__pa(p2m_missing))) {
 		/* p2m leaf page is missing */
 		unsigned long *p2m;
 
@@ -613,12 +563,25 @@ static bool alloc_p2m(unsigned long pfn)
 		if (!p2m)
 			return false;
 
-		p2m_init(p2m);
+		if (p2m_pfn == PFN_DOWN(__pa(p2m_missing)))
+			p2m_init(p2m);
+		else
+			p2m_init_identity(p2m, pfn);
+
+		spin_lock_irqsave(&p2m_update_lock, flags);
+
+		if (pte_pfn(*ptep) == p2m_pfn) {
+			set_pte(ptep,
+				pfn_pte(PFN_DOWN(__pa(p2m)), PAGE_KERNEL));
+			if (mid_mfn)
+				mid_mfn[mididx] = virt_to_mfn(p2m);
+			p2m = NULL;
+		}
+
+		spin_unlock_irqrestore(&p2m_update_lock, flags);
 
-		if (cmpxchg(&mid[mididx], p2m_orig, p2m) != p2m_orig)
+		if (p2m)
 			free_p2m_page(p2m);
-		else
-			mid_mfn[mididx] = virt_to_mfn(p2m);
 	}
 
 	return true;
@@ -647,10 +610,10 @@ unsigned long __init set_phys_range_identity(unsigned long pfn_s,
 	return pfn - pfn_s;
 }
 
-/* Try to install p2m mapping; fail if intermediate bits missing */
 bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
 {
-	unsigned topidx, mididx, idx;
+	pte_t *ptep;
+	unsigned int level;
 
 	/* don't track P2M changes in autotranslate guests */
 	if (unlikely(xen_feature(XENFEAT_auto_translated_physmap)))
@@ -661,55 +624,27 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn)
 		return true;
 	}
 
-	topidx = p2m_top_index(pfn);
-	mididx = p2m_mid_index(pfn);
-	idx = p2m_index(pfn);
-
-	/* For sparse holes were the p2m leaf has real PFN along with
-	 * PCI holes, stick in the PFN as the MFN value.
-	 *
-	 * set_phys_range_identity() will have allocated new middle
-	 * and leaf pages as required so an existing p2m_mid_missing
-	 * or p2m_missing mean that whole range will be identity so
-	 * these can be switched to p2m_mid_identity or p2m_identity.
-	 */
-	if (mfn != INVALID_P2M_ENTRY && (mfn & IDENTITY_FRAME_BIT)) {
-		if (p2m_top[topidx] == p2m_mid_identity)
-			return true;
-
-		if (p2m_top[topidx] == p2m_mid_missing) {
-			WARN_ON(cmpxchg(&p2m_top[topidx], p2m_mid_missing,
-					p2m_mid_identity) != p2m_mid_missing);
-			return true;
-		}
-
-		if (p2m_top[topidx][mididx] == p2m_identity)
-			return true;
-
-		/* Swap over from MISSING to IDENTITY if needed. */
-		if (p2m_top[topidx][mididx] == p2m_missing) {
-			WARN_ON(cmpxchg(&p2m_top[topidx][mididx], p2m_missing,
-				p2m_identity) != p2m_missing);
-			return true;
-		}
-	}
+	ptep = lookup_address((unsigned long)(xen_p2m_addr + pfn), &level);
+	BUG_ON(!ptep || level != PG_LEVEL_4K);
 
-	if (p2m_top[topidx][mididx] == p2m_missing)
+	if (pte_pfn(*ptep) == PFN_DOWN(__pa(p2m_missing)))
 		return mfn == INVALID_P2M_ENTRY;
 
-	p2m_top[topidx][mididx][idx] = mfn;
+	if (pte_pfn(*ptep) == PFN_DOWN(__pa(p2m_identity)))
+		return mfn == IDENTITY_FRAME(pfn);
+
+	xen_p2m_addr[pfn] = mfn;
 
 	return true;
 }
 
 bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
 {
-	if (unlikely(!__set_phys_to_machine(pfn, mfn)))  {
+	if (unlikely(!__set_phys_to_machine(pfn, mfn))) {
 		if (!alloc_p2m(pfn))
 			return false;
 
-		if (!__set_phys_to_machine(pfn, mfn))
-			return false;
+		return __set_phys_to_machine(pfn, mfn);
 	}
 
 	return true;
@@ -1035,79 +970,29 @@ EXPORT_SYMBOL_GPL(m2p_find_override_pfn);
 #include "debugfs.h"
 static int p2m_dump_show(struct seq_file *m, void *v)
 {
-	static const char * const level_name[] = { "top", "middle",
-						"entry", "abnormal", "error"};
-#define TYPE_IDENTITY 0
-#define TYPE_MISSING 1
-#define TYPE_PFN 2
-#define TYPE_UNKNOWN 3
 	static const char * const type_name[] = {
-				[TYPE_IDENTITY] = "identity",
-				[TYPE_MISSING] = "missing",
-				[TYPE_PFN] = "pfn",
-				[TYPE_UNKNOWN] = "abnormal"};
-	unsigned long pfn, prev_pfn_type = 0, prev_pfn_level = 0;
-	unsigned int uninitialized_var(prev_level);
-	unsigned int uninitialized_var(prev_type);
-
-	if (!p2m_top)
-		return 0;
-
-	for (pfn = 0; pfn < MAX_DOMAIN_PAGES; pfn++) {
-		unsigned topidx = p2m_top_index(pfn);
-		unsigned mididx = p2m_mid_index(pfn);
-		unsigned idx = p2m_index(pfn);
-		unsigned lvl, type;
-
-		lvl = 4;
-		type = TYPE_UNKNOWN;
-		if (p2m_top[topidx] == p2m_mid_missing) {
-			lvl = 0; type = TYPE_MISSING;
-		} else if (p2m_top[topidx] == NULL) {
-			lvl = 0; type = TYPE_UNKNOWN;
-		} else if (p2m_top[topidx][mididx] == NULL) {
-			lvl = 1; type = TYPE_UNKNOWN;
-		} else if (p2m_top[topidx][mididx] == p2m_identity) {
-			lvl = 1; type = TYPE_IDENTITY;
-		} else if (p2m_top[topidx][mididx] == p2m_missing) {
-			lvl = 1; type = TYPE_MISSING;
-		} else if (p2m_top[topidx][mididx][idx] == 0) {
-			lvl = 2; type = TYPE_UNKNOWN;
-		} else if (p2m_top[topidx][mididx][idx] == IDENTITY_FRAME(pfn)) {
-			lvl = 2; type = TYPE_IDENTITY;
-		} else if (p2m_top[topidx][mididx][idx] == INVALID_P2M_ENTRY) {
-			lvl = 2; type = TYPE_MISSING;
-		} else if (p2m_top[topidx][mididx][idx] == pfn) {
-			lvl = 2; type = TYPE_PFN;
-		} else if (p2m_top[topidx][mididx][idx] != pfn) {
-			lvl = 2; type = TYPE_PFN;
-		}
-		if (pfn == 0) {
-			prev_level = lvl;
+				[P2M_TYPE_IDENTITY] = "identity",
+				[P2M_TYPE_MISSING] = "missing",
+				[P2M_TYPE_PFN] = "pfn",
+				[P2M_TYPE_UNKNOWN] = "abnormal"};
+	unsigned long pfn, first_pfn;
+	int type, prev_type;
+
+	prev_type = xen_p2m_elem_type(0);
+	first_pfn = 0;
+
+	for (pfn = 0; pfn < xen_p2m_size; pfn++) {
+		type = xen_p2m_elem_type(pfn);
+		if (type != prev_type) {
+			seq_printf(m, " [0x%lx->0x%lx] %s\n", first_pfn, pfn,
+				   type_name[prev_type]);
 			prev_type = type;
-		}
-		if (pfn == MAX_DOMAIN_PAGES-1) {
-			lvl = 3;
-			type = TYPE_UNKNOWN;
-		}
-		if (prev_type != type) {
-			seq_printf(m, " [0x%lx->0x%lx] %s\n",
-				prev_pfn_type, pfn, type_name[prev_type]);
-			prev_pfn_type = pfn;
-			prev_type = type;
-		}
-		if (prev_level != lvl) {
-			seq_printf(m, " [0x%lx->0x%lx] level %s\n",
-				prev_pfn_level, pfn, level_name[prev_level]);
-			prev_pfn_level = pfn;
-			prev_level = lvl;
+			first_pfn = pfn;
 		}
 	}
+	seq_printf(m, " [0x%lx->0x%lx] %s\n", first_pfn, pfn,
+		   type_name[prev_type]);
 	return 0;
-#undef TYPE_IDENTITY
-#undef TYPE_MISSING
-#undef TYPE_PFN
-#undef TYPE_UNKNOWN
 }
 
 static int p2m_dump_open(struct inode *inode, struct file *filp)
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 02b0b0fba041118034a205b4750f9eac8c40d1fd..f92921fa54f9a562bb183ad3cb00a6a28316445e 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -49,7 +49,7 @@ void xen_hvm_init_shared_info(void);
 void xen_unplug_emulated_devices(void);
 
 void __init xen_build_dynamic_phys_to_machine(void);
-unsigned long __init xen_revector_p2m_tree(void);
+void __init xen_vmalloc_p2m_tree(void);
 
 void xen_init_irq_ops(void);
 void xen_setup_timer(int cpu);