1 files changed, 263 insertions, 51 deletions

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index aa37469da696..ae173f6edd8b 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -40,6 +40,7 @@
  */
 #include <linux/sched.h>
 #include <linux/highmem.h>
+#include <linux/debugfs.h>
 #include <linux/bug.h>
 
 #include <asm/pgtable.h>
@@ -57,6 +58,61 @@
 
 #include "multicalls.h"
 #include "mmu.h"
+#include "debugfs.h"
+
+#define MMU_UPDATE_HISTO        30
+
+#ifdef CONFIG_XEN_DEBUG_FS
+
+static struct {
+        u32 pgd_update;
+        u32 pgd_update_pinned;
+        u32 pgd_update_batched;
+
+        u32 pud_update;
+        u32 pud_update_pinned;
+        u32 pud_update_batched;
+
+        u32 pmd_update;
+        u32 pmd_update_pinned;
+        u32 pmd_update_batched;
+
+        u32 pte_update;
+        u32 pte_update_pinned;
+        u32 pte_update_batched;
+
+        u32 mmu_update;
+        u32 mmu_update_extended;
+        u32 mmu_update_histo[MMU_UPDATE_HISTO];
+
+        u32 prot_commit;
+        u32 prot_commit_batched;
+
+        u32 set_pte_at;
+        u32 set_pte_at_batched;
+        u32 set_pte_at_pinned;
+        u32 set_pte_at_current;
+        u32 set_pte_at_kernel;
+} mmu_stats;
+
+static u8 zero_stats;
+
+static inline void check_zero(void)
+{
+        if (unlikely(zero_stats)) {
+                memset(&mmu_stats, 0, sizeof(mmu_stats));
+                zero_stats = 0;
+        }
+}
+
+#define ADD_STATS(elem, val)                    \
+        do { check_zero(); mmu_stats.elem += (val); } while(0)
+
+#else  /* !CONFIG_XEN_DEBUG_FS */
+
+#define ADD_STATS(elem, val)    do { (void)(val); } while(0)
+
+#endif /* CONFIG_XEN_DEBUG_FS */
 
 /*
  * Just beyond the highest usermode address.  STACK_TOP_MAX has a
@@ -229,25 +285,35 @@ void make_lowmem_page_readwrite(void *vaddr)
 }
 
 
-static bool page_pinned(void *ptr)
+static bool xen_page_pinned(void *ptr)
 {
         struct page *page = virt_to_page(ptr);
 
         return PagePinned(page);
 }
 
-static void extend_mmu_update(const struct mmu_update *update)
+static void xen_extend_mmu_update(const struct mmu_update *update)
 {
         struct multicall_space mcs;
         struct mmu_update *u;
 
         mcs = xen_mc_extend_args(__HYPERVISOR_mmu_update, sizeof(*u));
 
-        if (mcs.mc != NULL)
+        if (mcs.mc != NULL) {
+                ADD_STATS(mmu_update_extended, 1);
+                ADD_STATS(mmu_update_histo[mcs.mc->args[1]], -1);
+
                 mcs.mc->args[1]++;
-        else {
+
+                if (mcs.mc->args[1] < MMU_UPDATE_HISTO)
+                        ADD_STATS(mmu_update_histo[mcs.mc->args[1]], 1);
+                else
+                        ADD_STATS(mmu_update_histo[0], 1);
+        } else {
+                ADD_STATS(mmu_update, 1);
                 mcs = __xen_mc_entry(sizeof(*u));
                 MULTI_mmu_update(mcs.mc, mcs.args, 1, NULL, DOMID_SELF);
+                ADD_STATS(mmu_update_histo[1], 1);
         }
 
         u = mcs.args;
@@ -265,7 +331,9 @@ void xen_set_pmd_hyper(pmd_t *ptr, pmd_t val)
         /* ptr may be ioremapped for 64-bit pagetable setup */
         u.ptr = arbitrary_virt_to_machine(ptr).maddr;
         u.val = pmd_val_ma(val);
-        extend_mmu_update(&u);
+        xen_extend_mmu_update(&u);
+
+        ADD_STATS(pmd_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
 
         xen_mc_issue(PARAVIRT_LAZY_MMU);
 
@@ -274,13 +342,17 @@ void xen_set_pmd_hyper(pmd_t *ptr, pmd_t val)
 
 void xen_set_pmd(pmd_t *ptr, pmd_t val)
 {
+        ADD_STATS(pmd_update, 1);
+
         /* If page is not pinned, we can just update the entry
            directly */
-        if (!page_pinned(ptr)) {
+        if (!xen_page_pinned(ptr)) {
                 *ptr = val;
                 return;
         }
 
+        ADD_STATS(pmd_update_pinned, 1);
+
         xen_set_pmd_hyper(ptr, val);
 }
 
@@ -300,12 +372,18 @@ void xen_set_pte_at(struct mm_struct *mm, unsigned long addr,
         if (mm == &init_mm)
                 preempt_disable();
 
+        ADD_STATS(set_pte_at, 1);
+//      ADD_STATS(set_pte_at_pinned, xen_page_pinned(ptep));
+        ADD_STATS(set_pte_at_current, mm == current->mm);
+        ADD_STATS(set_pte_at_kernel, mm == &init_mm);
+
         if (mm == current->mm || mm == &init_mm) {
                 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
                         struct multicall_space mcs;
                         mcs = xen_mc_entry(0);
 
                         MULTI_update_va_mapping(mcs.mc, addr, pteval, 0);
+                        ADD_STATS(set_pte_at_batched, 1);
                         xen_mc_issue(PARAVIRT_LAZY_MMU);
                         goto out;
                 } else
@@ -334,7 +412,10 @@ void xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
 
         u.ptr = virt_to_machine(ptep).maddr | MMU_PT_UPDATE_PRESERVE_AD;
         u.val = pte_val_ma(pte);
-        extend_mmu_update(&u);
+        xen_extend_mmu_update(&u);
+
+        ADD_STATS(prot_commit, 1);
+        ADD_STATS(prot_commit_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
 
         xen_mc_issue(PARAVIRT_LAZY_MMU);
 }
@@ -400,7 +481,9 @@ void xen_set_pud_hyper(pud_t *ptr, pud_t val)
         /* ptr may be ioremapped for 64-bit pagetable setup */
         u.ptr = arbitrary_virt_to_machine(ptr).maddr;
         u.val = pud_val_ma(val);
-        extend_mmu_update(&u);
+        xen_extend_mmu_update(&u);
+
+        ADD_STATS(pud_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
 
         xen_mc_issue(PARAVIRT_LAZY_MMU);
 
@@ -409,18 +492,26 @@ void xen_set_pud_hyper(pud_t *ptr, pud_t val)
 
 void xen_set_pud(pud_t *ptr, pud_t val)
 {
+        ADD_STATS(pud_update, 1);
+
         /* If page is not pinned, we can just update the entry
            directly */
-        if (!page_pinned(ptr)) {
+        if (!xen_page_pinned(ptr)) {
                 *ptr = val;
                 return;
         }
 
+        ADD_STATS(pud_update_pinned, 1);
+
         xen_set_pud_hyper(ptr, val);
 }
 
 void xen_set_pte(pte_t *ptep, pte_t pte)
 {
+        ADD_STATS(pte_update, 1);
+//      ADD_STATS(pte_update_pinned, xen_page_pinned(ptep));
+        ADD_STATS(pte_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
+
 #ifdef CONFIG_X86_PAE
         ptep->pte_high = pte.pte_high;
         smp_wmb();
@@ -490,7 +581,7 @@ static void __xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
 
         u.ptr = virt_to_machine(ptr).maddr;
         u.val = pgd_val_ma(val);
-        extend_mmu_update(&u);
+        xen_extend_mmu_update(&u);
 }
 
 /*
@@ -517,17 +608,22 @@ void xen_set_pgd(pgd_t *ptr, pgd_t val)
 {
         pgd_t *user_ptr = xen_get_user_pgd(ptr);
 
+        ADD_STATS(pgd_update, 1);
+
         /* If page is not pinned, we can just update the entry
            directly */
-        if (!page_pinned(ptr)) {
+        if (!xen_page_pinned(ptr)) {
                 *ptr = val;
                 if (user_ptr) {
-                        WARN_ON(page_pinned(user_ptr));
+                        WARN_ON(xen_page_pinned(user_ptr));
                         *user_ptr = val;
                 }
                 return;
         }
 
+        ADD_STATS(pgd_update_pinned, 1);
+        ADD_STATS(pgd_update_batched, paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU);
+
         /* If it's pinned, then we can at least batch the kernel and
            user updates together. */
         xen_mc_batch();
@@ -555,9 +651,12 @@ void xen_set_pgd(pgd_t *ptr, pgd_t val)
  * For 64-bit, we must skip the Xen hole in the middle of the address
  * space, just after the big x86-64 virtual hole.
  */
-static int pgd_walk(pgd_t *pgd, int (*func)(struct page *, enum pt_level),
-                    unsigned long limit)
+static int xen_pgd_walk(struct mm_struct *mm,
+                        int (*func)(struct mm_struct *mm, struct page *,
+                                    enum pt_level),
+                        unsigned long limit)
 {
+        pgd_t *pgd = mm->pgd;
         int flush = 0;
         unsigned hole_low, hole_high;
         unsigned pgdidx_limit, pudidx_limit, pmdidx_limit;
@@ -590,8 +689,6 @@ static int pgd_walk(pgd_t *pgd, int (*func)(struct page *, enum pt_level),
         pmdidx_limit = 0;
 #endif
 
-        flush |= (*func)(virt_to_page(pgd), PT_PGD);
-
         for (pgdidx = 0; pgdidx <= pgdidx_limit; pgdidx++) {
                 pud_t *pud;
 
@@ -604,7 +701,7 @@ static int pgd_walk(pgd_t *pgd, int (*func)(struct page *, enum pt_level),
                 pud = pud_offset(&pgd[pgdidx], 0);
 
                 if (PTRS_PER_PUD > 1) /* not folded */
-                        flush |= (*func)(virt_to_page(pud), PT_PUD);
+                        flush |= (*func)(mm, virt_to_page(pud), PT_PUD);
 
                 for (pudidx = 0; pudidx < PTRS_PER_PUD; pudidx++) {
                         pmd_t *pmd;
@@ -619,7 +716,7 @@ static int pgd_walk(pgd_t *pgd, int (*func)(struct page *, enum pt_level),
                         pmd = pmd_offset(&pud[pudidx], 0);
 
                         if (PTRS_PER_PMD > 1) /* not folded */
-                                flush |= (*func)(virt_to_page(pmd), PT_PMD);
+                                flush |= (*func)(mm, virt_to_page(pmd), PT_PMD);
 
                         for (pmdidx = 0; pmdidx < PTRS_PER_PMD; pmdidx++) {
                                 struct page *pte;
@@ -633,28 +730,34 @@ static int pgd_walk(pgd_t *pgd, int (*func)(struct page *, enum pt_level),
                                         continue;
 
                                 pte = pmd_page(pmd[pmdidx]);
-                                flush |= (*func)(pte, PT_PTE);
+                                flush |= (*func)(mm, pte, PT_PTE);
                         }
                 }
         }
+
 out:
+        /* Do the top level last, so that the callbacks can use it as
+           a cue to do final things like tlb flushes. */
+        flush |= (*func)(mm, virt_to_page(pgd), PT_PGD);
 
         return flush;
 }
 
-static spinlock_t *lock_pte(struct page *page)
+/* If we're using split pte locks, then take the page's lock and
+   return a pointer to it.  Otherwise return NULL. */
+static spinlock_t *xen_pte_lock(struct page *page, struct mm_struct *mm)
 {
         spinlock_t *ptl = NULL;
 
-#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
+#if USE_SPLIT_PTLOCKS
         ptl = __pte_lockptr(page);
-        spin_lock(ptl);
+        spin_lock_nest_lock(ptl, &mm->page_table_lock);
 #endif
 
         return ptl;
 }
 
-static void do_unlock(void *v)
+static void xen_pte_unlock(void *v)
 {
         spinlock_t *ptl = v;
         spin_unlock(ptl);
@@ -672,7 +775,8 @@ static void xen_do_pin(unsigned level, unsigned long pfn)
         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
 }
 
-static int pin_page(struct page *page, enum pt_level level)
+static int xen_pin_page(struct mm_struct *mm, struct page *page,
+                        enum pt_level level)
 {
         unsigned pgfl = TestSetPagePinned(page);
         int flush;
@@ -691,21 +795,40 @@ static int pin_page(struct page *page, enum pt_level level)
 
                 flush = 0;
 
+                /*
+                 * We need to hold the pagetable lock between the time
+                 * we make the pagetable RO and when we actually pin
+                 * it.  If we don't, then other users may come in and
+                 * attempt to update the pagetable by writing it,
+                 * which will fail because the memory is RO but not
+                 * pinned, so Xen won't do the trap'n'emulate.
+                 *
+                 * If we're using split pte locks, we can't hold the
+                 * entire pagetable's worth of locks during the
+                 * traverse, because we may wrap the preempt count (8
+                 * bits).  The solution is to mark RO and pin each PTE
+                 * page while holding the lock.  This means the number
+                 * of locks we end up holding is never more than a
+                 * batch size (~32 entries, at present).
+                 *
+                 * If we're not using split pte locks, we needn't pin
+                 * the PTE pages independently, because we're
+                 * protected by the overall pagetable lock.
+                 */
                 ptl = NULL;
                 if (level == PT_PTE)
-                        ptl = lock_pte(page);
+                        ptl = xen_pte_lock(page, mm);
 
                 MULTI_update_va_mapping(mcs.mc, (unsigned long)pt,
                                         pfn_pte(pfn, PAGE_KERNEL_RO),
                                         level == PT_PGD ? UVMF_TLB_FLUSH : 0);
 
-                if (level == PT_PTE)
+                if (ptl) {
                         xen_do_pin(MMUEXT_PIN_L1_TABLE, pfn);
 
-                if (ptl) {
                         /* Queue a deferred unlock for when this batch
                            is completed. */
-                        xen_mc_callback(do_unlock, ptl);
+                        xen_mc_callback(xen_pte_unlock, ptl);
                 }
         }
 
@@ -715,11 +838,11 @@ static int pin_page(struct page *page, enum pt_level level)
 /* This is called just after a mm has been created, but it has not
    been used yet.  We need to make sure that its pagetable is all
    read-only, and can be pinned. */
-void xen_pgd_pin(pgd_t *pgd)
+static void __xen_pgd_pin(struct mm_struct *mm, pgd_t *pgd)
 {
         xen_mc_batch();
 
-        if (pgd_walk(pgd, pin_page, USER_LIMIT)) {
+        if (xen_pgd_walk(mm, xen_pin_page, USER_LIMIT)) {
                 /* re-enable interrupts for kmap_flush_unused */
                 xen_mc_issue(0);
                 kmap_flush_unused();
@@ -733,25 +856,35 @@ void xen_pgd_pin(pgd_t *pgd)
                 xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(pgd)));
 
                 if (user_pgd) {
-                        pin_page(virt_to_page(user_pgd), PT_PGD);
+                        xen_pin_page(mm, virt_to_page(user_pgd), PT_PGD);
                         xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(user_pgd)));
                 }
         }
 #else /* CONFIG_X86_32 */
 #ifdef CONFIG_X86_PAE
         /* Need to make sure unshared kernel PMD is pinnable */
-        pin_page(virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])), PT_PMD);
+        xen_pin_page(mm, virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])),
+                     PT_PMD);
 #endif
         xen_do_pin(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(pgd)));
 #endif /* CONFIG_X86_64 */
         xen_mc_issue(0);
 }
 
+static void xen_pgd_pin(struct mm_struct *mm)
+{
+        __xen_pgd_pin(mm, mm->pgd);
+}
+
 /*
  * On save, we need to pin all pagetables to make sure they get their
  * mfns turned into pfns.  Search the list for any unpinned pgds and pin
  * them (unpinned pgds are not currently in use, probably because the
  * process is under construction or destruction).
+ *
+ * Expected to be called in stop_machine() ("equivalent to taking
+ * every spinlock in the system"), so the locking doesn't really
+ * matter all that much.
  */
 void xen_mm_pin_all(void)
 {
@@ -762,7 +895,7 @@ void xen_mm_pin_all(void)
 
         list_for_each_entry(page, &pgd_list, lru) {
                 if (!PagePinned(page)) {
-                        xen_pgd_pin((pgd_t *)page_address(page));
+                        __xen_pgd_pin(&init_mm, (pgd_t *)page_address(page));
                         SetPageSavePinned(page);
                 }
         }
@@ -775,7 +908,8 @@ void xen_mm_pin_all(void)
  * that's before we have page structures to store the bits.  So do all
  * the book-keeping now.
  */
-static __init int mark_pinned(struct page *page, enum pt_level level)
+static __init int xen_mark_pinned(struct mm_struct *mm, struct page *page,
+                                  enum pt_level level)
 {
         SetPagePinned(page);
         return 0;
@@ -783,10 +917,11 @@ static __init int mark_pinned(struct page *page, enum pt_level level)
 
 void __init xen_mark_init_mm_pinned(void)
 {
-        pgd_walk(init_mm.pgd, mark_pinned, FIXADDR_TOP);
+        xen_pgd_walk(&init_mm, xen_mark_pinned, FIXADDR_TOP);
 }
 
-static int unpin_page(struct page *page, enum pt_level level)
+static int xen_unpin_page(struct mm_struct *mm, struct page *page,
+                          enum pt_level level)
 {
         unsigned pgfl = TestClearPagePinned(page);
 
@@ -796,10 +931,18 @@ static int unpin_page(struct page *page, enum pt_level level)
                 spinlock_t *ptl = NULL;
                 struct multicall_space mcs;
 
+                /*
+                 * Do the converse to pin_page.  If we're using split
+                 * pte locks, we must be holding the lock for while
+                 * the pte page is unpinned but still RO to prevent
+                 * concurrent updates from seeing it in this
+                 * partially-pinned state.
+                 */
                 if (level == PT_PTE) {
-                        ptl = lock_pte(page);
+                        ptl = xen_pte_lock(page, mm);
 
-                        xen_do_pin(MMUEXT_UNPIN_TABLE, pfn);
+                        if (ptl)
+                                xen_do_pin(MMUEXT_UNPIN_TABLE, pfn);
                 }
 
                 mcs = __xen_mc_entry(0);
@@ -810,7 +953,7 @@ static int unpin_page(struct page *page, enum pt_level level)
 
                 if (ptl) {
                         /* unlock when batch completed */
-                        xen_mc_callback(do_unlock, ptl);
+                        xen_mc_callback(xen_pte_unlock, ptl);
                 }
         }
 
@@ -818,7 +961,7 @@ static int unpin_page(struct page *page, enum pt_level level)
 }
 
 /* Release a pagetables pages back as normal RW */
-static void xen_pgd_unpin(pgd_t *pgd)
+static void __xen_pgd_unpin(struct mm_struct *mm, pgd_t *pgd)
 {
         xen_mc_batch();
 
@@ -830,21 +973,27 @@ static void xen_pgd_unpin(pgd_t *pgd)
 
                 if (user_pgd) {
                         xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(user_pgd)));
-                        unpin_page(virt_to_page(user_pgd), PT_PGD);
+                        xen_unpin_page(mm, virt_to_page(user_pgd), PT_PGD);
                 }
         }
 #endif
 
 #ifdef CONFIG_X86_PAE
         /* Need to make sure unshared kernel PMD is unpinned */
-        pin_page(virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])), PT_PMD);
+        xen_unpin_page(mm, virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])),
+                       PT_PMD);
 #endif
 
-        pgd_walk(pgd, unpin_page, USER_LIMIT);
+        xen_pgd_walk(mm, xen_unpin_page, USER_LIMIT);
 
         xen_mc_issue(0);
 }
 
+static void xen_pgd_unpin(struct mm_struct *mm)
+{
+        __xen_pgd_unpin(mm, mm->pgd);
+}
+
 /*
  * On resume, undo any pinning done at save, so that the rest of the
  * kernel doesn't see any unexpected pinned pagetables.
@@ -859,7 +1008,7 @@ void xen_mm_unpin_all(void)
         list_for_each_entry(page, &pgd_list, lru) {
                 if (PageSavePinned(page)) {
                         BUG_ON(!PagePinned(page));
-                        xen_pgd_unpin((pgd_t *)page_address(page));
+                        __xen_pgd_unpin(&init_mm, (pgd_t *)page_address(page));
                         ClearPageSavePinned(page);
                 }
         }
@@ -870,14 +1019,14 @@ void xen_mm_unpin_all(void)
 void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next)
 {
         spin_lock(&next->page_table_lock);
-        xen_pgd_pin(next->pgd);
+        xen_pgd_pin(next);
         spin_unlock(&next->page_table_lock);
 }
 
 void xen_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm)
 {
         spin_lock(&mm->page_table_lock);
-        xen_pgd_pin(mm->pgd);
+        xen_pgd_pin(mm);
         spin_unlock(&mm->page_table_lock);
 }
 
@@ -907,7 +1056,7 @@ static void drop_other_mm_ref(void *info)
         }
 }
 
-static void drop_mm_ref(struct mm_struct *mm)
+static void xen_drop_mm_ref(struct mm_struct *mm)
 {
         cpumask_t mask;
         unsigned cpu;
@@ -937,7 +1086,7 @@ static void drop_mm_ref(struct mm_struct *mm)
                 smp_call_function_mask(mask, drop_other_mm_ref, mm, 1);
 }
 #else
-static void drop_mm_ref(struct mm_struct *mm)
+static void xen_drop_mm_ref(struct mm_struct *mm)
 {
         if (current->active_mm == mm)
                 load_cr3(swapper_pg_dir);
@@ -961,14 +1110,77 @@ static void drop_mm_ref(struct mm_struct *mm)
 void xen_exit_mmap(struct mm_struct *mm)
 {
         get_cpu();              /* make sure we don't move around */
-        drop_mm_ref(mm);
+        xen_drop_mm_ref(mm);
         put_cpu();
 
         spin_lock(&mm->page_table_lock);
 
         /* pgd may not be pinned in the error exit path of execve */
-        if (page_pinned(mm->pgd))
-                xen_pgd_unpin(mm->pgd);
+        if (xen_page_pinned(mm->pgd))
+                xen_pgd_unpin(mm);
 
         spin_unlock(&mm->page_table_lock);
 }
+
+#ifdef CONFIG_XEN_DEBUG_FS
+
+static struct dentry *d_mmu_debug;
+
+static int __init xen_mmu_debugfs(void)
+{
+        struct dentry *d_xen = xen_init_debugfs();
+
+        if (d_xen == NULL)
+                return -ENOMEM;
+
+        d_mmu_debug = debugfs_create_dir("mmu", d_xen);
+
+        debugfs_create_u8("zero_stats", 0644, d_mmu_debug, &zero_stats);
+
+        debugfs_create_u32("pgd_update", 0444, d_mmu_debug, &mmu_stats.pgd_update);
+        debugfs_create_u32("pgd_update_pinned", 0444, d_mmu_debug,
+                           &mmu_stats.pgd_update_pinned);
+        debugfs_create_u32("pgd_update_batched", 0444, d_mmu_debug,
+                           &mmu_stats.pgd_update_pinned);
+
+        debugfs_create_u32("pud_update", 0444, d_mmu_debug, &mmu_stats.pud_update);
+        debugfs_create_u32("pud_update_pinned", 0444, d_mmu_debug,
+                           &mmu_stats.pud_update_pinned);
+        debugfs_create_u32("pud_update_batched", 0444, d_mmu_debug,
+                           &mmu_stats.pud_update_pinned);
+
+        debugfs_create_u32("pmd_update", 0444, d_mmu_debug, &mmu_stats.pmd_update);
+        debugfs_create_u32("pmd_update_pinned", 0444, d_mmu_debug,
+                           &mmu_stats.pmd_update_pinned);
+        debugfs_create_u32("pmd_update_batched", 0444, d_mmu_debug,
+                           &mmu_stats.pmd_update_pinned);
+
+        debugfs_create_u32("pte_update", 0444, d_mmu_debug, &mmu_stats.pte_update);
+//      debugfs_create_u32("pte_update_pinned", 0444, d_mmu_debug,
+//                         &mmu_stats.pte_update_pinned);
+        debugfs_create_u32("pte_update_batched", 0444, d_mmu_debug,
+                           &mmu_stats.pte_update_pinned);
+
+        debugfs_create_u32("mmu_update", 0444, d_mmu_debug, &mmu_stats.mmu_update);
+        debugfs_create_u32("mmu_update_extended", 0444, d_mmu_debug,
+                           &mmu_stats.mmu_update_extended);
+        xen_debugfs_create_u32_array("mmu_update_histo", 0444, d_mmu_debug,
+                                     mmu_stats.mmu_update_histo, 20);
+
+        debugfs_create_u32("set_pte_at", 0444, d_mmu_debug, &mmu_stats.set_pte_at);
+        debugfs_create_u32("set_pte_at_batched", 0444, d_mmu_debug,
+                           &mmu_stats.set_pte_at_batched);
+        debugfs_create_u32("set_pte_at_current", 0444, d_mmu_debug,
+                           &mmu_stats.set_pte_at_current);
+        debugfs_create_u32("set_pte_at_kernel", 0444, d_mmu_debug,
+                           &mmu_stats.set_pte_at_kernel);
+
+        debugfs_create_u32("prot_commit", 0444, d_mmu_debug, &mmu_stats.prot_commit);
+        debugfs_create_u32("prot_commit_batched", 0444, d_mmu_debug,
+                           &mmu_stats.prot_commit_batched);
+
+        return 0;
+}
+fs_initcall(xen_mmu_debugfs);
+
+#endif  /* CONFIG_XEN_DEBUG_FS */