KVM: MMU: optimize set_spte for page sync
[safe/jmp/linux-2.6] / arch / x86 / kvm / mmu.c
index 21cfa28..dd20b19 100644 (file)
@@ -17,7 +17,6 @@
  *
  */
 
-#include "vmx.h"
 #include "mmu.h"
 
 #include <linux/kvm_host.h>
 #include <linux/highmem.h>
 #include <linux/module.h>
 #include <linux/swap.h>
+#include <linux/hugetlb.h>
+#include <linux/compiler.h>
 
 #include <asm/page.h>
 #include <asm/cmpxchg.h>
 #include <asm/io.h>
+#include <asm/vmx.h>
 
 /*
  * When setting this variable to true it enables Two-Dimensional-Paging
@@ -39,7 +41,7 @@
  * 2. while doing 1. it walks guest-physical to host-physical
  * If the hardware supports that we don't need to do shadow paging.
  */
-static bool tdp_enabled = false;
+bool tdp_enabled = false;
 
 #undef MMU_DEBUG
 
@@ -64,9 +66,13 @@ static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
 #endif
 
 #if defined(MMU_DEBUG) || defined(AUDIT)
-static int dbg = 1;
+static int dbg = 0;
+module_param(dbg, bool, 0644);
 #endif
 
+static int oos_shadow = 1;
+module_param(oos_shadow, bool, 0644);
+
 #ifndef MMU_DEBUG
 #define ASSERT(x) do { } while (0)
 #else
@@ -77,36 +83,6 @@ static int dbg = 1;
        }
 #endif
 
-#define PT64_PT_BITS 9
-#define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
-#define PT32_PT_BITS 10
-#define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
-
-#define PT_WRITABLE_SHIFT 1
-
-#define PT_PRESENT_MASK (1ULL << 0)
-#define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
-#define PT_USER_MASK (1ULL << 2)
-#define PT_PWT_MASK (1ULL << 3)
-#define PT_PCD_MASK (1ULL << 4)
-#define PT_ACCESSED_MASK (1ULL << 5)
-#define PT_DIRTY_MASK (1ULL << 6)
-#define PT_PAGE_SIZE_MASK (1ULL << 7)
-#define PT_PAT_MASK (1ULL << 7)
-#define PT_GLOBAL_MASK (1ULL << 8)
-#define PT64_NX_SHIFT 63
-#define PT64_NX_MASK (1ULL << PT64_NX_SHIFT)
-
-#define PT_PAT_SHIFT 7
-#define PT_DIR_PAT_SHIFT 12
-#define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
-
-#define PT32_DIR_PSE36_SIZE 4
-#define PT32_DIR_PSE36_SHIFT 13
-#define PT32_DIR_PSE36_MASK \
-       (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
-
-
 #define PT_FIRST_AVAIL_BITS_SHIFT 9
 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
 
@@ -152,10 +128,6 @@ static int dbg = 1;
 #define PFERR_USER_MASK (1U << 2)
 #define PFERR_FETCH_MASK (1U << 4)
 
-#define PT64_ROOT_LEVEL 4
-#define PT32_ROOT_LEVEL 2
-#define PT32E_ROOT_LEVEL 3
-
 #define PT_DIRECTORY_LEVEL 2
 #define PT_PAGE_TABLE_LEVEL 1
 
@@ -166,17 +138,37 @@ static int dbg = 1;
 #define ACC_USER_MASK    PT_USER_MASK
 #define ACC_ALL          (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
 
+#define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
+
 struct kvm_rmap_desc {
        u64 *shadow_ptes[RMAP_EXT];
        struct kvm_rmap_desc *more;
 };
 
+struct kvm_shadow_walk {
+       int (*entry)(struct kvm_shadow_walk *walk, struct kvm_vcpu *vcpu,
+                    u64 addr, u64 *spte, int level);
+};
+
+struct kvm_unsync_walk {
+       int (*entry) (struct kvm_mmu_page *sp, struct kvm_unsync_walk *walk);
+};
+
+typedef int (*mmu_parent_walk_fn) (struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp);
+
 static struct kmem_cache *pte_chain_cache;
 static struct kmem_cache *rmap_desc_cache;
 static struct kmem_cache *mmu_page_header_cache;
 
 static u64 __read_mostly shadow_trap_nonpresent_pte;
 static u64 __read_mostly shadow_notrap_nonpresent_pte;
+static u64 __read_mostly shadow_base_present_pte;
+static u64 __read_mostly shadow_nx_mask;
+static u64 __read_mostly shadow_x_mask;        /* mutual exclusive with nx_mask */
+static u64 __read_mostly shadow_user_mask;
+static u64 __read_mostly shadow_accessed_mask;
+static u64 __read_mostly shadow_dirty_mask;
+static u64 __read_mostly shadow_mt_mask;
 
 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
 {
@@ -185,6 +177,24 @@ void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes);
 
+void kvm_mmu_set_base_ptes(u64 base_pte)
+{
+       shadow_base_present_pte = base_pte;
+}
+EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes);
+
+void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
+               u64 dirty_mask, u64 nx_mask, u64 x_mask, u64 mt_mask)
+{
+       shadow_user_mask = user_mask;
+       shadow_accessed_mask = accessed_mask;
+       shadow_dirty_mask = dirty_mask;
+       shadow_nx_mask = nx_mask;
+       shadow_x_mask = x_mask;
+       shadow_mt_mask = mt_mask;
+}
+EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
+
 static int is_write_protection(struct kvm_vcpu *vcpu)
 {
        return vcpu->arch.cr0 & X86_CR0_WP;
@@ -211,6 +221,11 @@ static int is_shadow_present_pte(u64 pte)
                && pte != shadow_notrap_nonpresent_pte;
 }
 
+static int is_large_pte(u64 pte)
+{
+       return pte & PT_PAGE_SIZE_MASK;
+}
+
 static int is_writeble_pte(unsigned long pte)
 {
        return pte & PT_WRITABLE_MASK;
@@ -218,7 +233,7 @@ static int is_writeble_pte(unsigned long pte)
 
 static int is_dirty_pte(unsigned long pte)
 {
-       return pte & PT_DIRTY_MASK;
+       return pte & shadow_dirty_mask;
 }
 
 static int is_rmap_pte(u64 pte)
@@ -226,6 +241,11 @@ static int is_rmap_pte(u64 pte)
        return is_shadow_present_pte(pte);
 }
 
+static pfn_t spte_to_pfn(u64 pte)
+{
+       return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
+}
+
 static gfn_t pse36_gfn_delta(u32 gpte)
 {
        int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
@@ -296,7 +316,7 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
        if (r)
                goto out;
        r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache,
-                                  rmap_desc_cache, 1);
+                                  rmap_desc_cache, 4);
        if (r)
                goto out;
        r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
@@ -350,16 +370,108 @@ static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
 }
 
 /*
+ * Return the pointer to the largepage write count for a given
+ * gfn, handling slots that are not large page aligned.
+ */
+static int *slot_largepage_idx(gfn_t gfn, struct kvm_memory_slot *slot)
+{
+       unsigned long idx;
+
+       idx = (gfn / KVM_PAGES_PER_HPAGE) -
+             (slot->base_gfn / KVM_PAGES_PER_HPAGE);
+       return &slot->lpage_info[idx].write_count;
+}
+
+static void account_shadowed(struct kvm *kvm, gfn_t gfn)
+{
+       int *write_count;
+
+       gfn = unalias_gfn(kvm, gfn);
+       write_count = slot_largepage_idx(gfn,
+                                        gfn_to_memslot_unaliased(kvm, gfn));
+       *write_count += 1;
+}
+
+static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn)
+{
+       int *write_count;
+
+       gfn = unalias_gfn(kvm, gfn);
+       write_count = slot_largepage_idx(gfn,
+                                        gfn_to_memslot_unaliased(kvm, gfn));
+       *write_count -= 1;
+       WARN_ON(*write_count < 0);
+}
+
+static int has_wrprotected_page(struct kvm *kvm, gfn_t gfn)
+{
+       struct kvm_memory_slot *slot;
+       int *largepage_idx;
+
+       gfn = unalias_gfn(kvm, gfn);
+       slot = gfn_to_memslot_unaliased(kvm, gfn);
+       if (slot) {
+               largepage_idx = slot_largepage_idx(gfn, slot);
+               return *largepage_idx;
+       }
+
+       return 1;
+}
+
+static int host_largepage_backed(struct kvm *kvm, gfn_t gfn)
+{
+       struct vm_area_struct *vma;
+       unsigned long addr;
+       int ret = 0;
+
+       addr = gfn_to_hva(kvm, gfn);
+       if (kvm_is_error_hva(addr))
+               return ret;
+
+       down_read(&current->mm->mmap_sem);
+       vma = find_vma(current->mm, addr);
+       if (vma && is_vm_hugetlb_page(vma))
+               ret = 1;
+       up_read(&current->mm->mmap_sem);
+
+       return ret;
+}
+
+static int is_largepage_backed(struct kvm_vcpu *vcpu, gfn_t large_gfn)
+{
+       struct kvm_memory_slot *slot;
+
+       if (has_wrprotected_page(vcpu->kvm, large_gfn))
+               return 0;
+
+       if (!host_largepage_backed(vcpu->kvm, large_gfn))
+               return 0;
+
+       slot = gfn_to_memslot(vcpu->kvm, large_gfn);
+       if (slot && slot->dirty_bitmap)
+               return 0;
+
+       return 1;
+}
+
+/*
  * Take gfn and return the reverse mapping to it.
  * Note: gfn must be unaliased before this function get called
  */
 
-static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn)
+static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int lpage)
 {
        struct kvm_memory_slot *slot;
+       unsigned long idx;
 
        slot = gfn_to_memslot(kvm, gfn);
-       return &slot->rmap[gfn - slot->base_gfn];
+       if (!lpage)
+               return &slot->rmap[gfn - slot->base_gfn];
+
+       idx = (gfn / KVM_PAGES_PER_HPAGE) -
+             (slot->base_gfn / KVM_PAGES_PER_HPAGE);
+
+       return &slot->lpage_info[idx].rmap_pde;
 }
 
 /*
@@ -371,7 +483,7 @@ static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn)
  * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
  * containing more mappings.
  */
-static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
+static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn, int lpage)
 {
        struct kvm_mmu_page *sp;
        struct kvm_rmap_desc *desc;
@@ -383,7 +495,7 @@ static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
        gfn = unalias_gfn(vcpu->kvm, gfn);
        sp = page_header(__pa(spte));
        sp->gfns[spte - sp->spt] = gfn;
-       rmapp = gfn_to_rmap(vcpu->kvm, gfn);
+       rmapp = gfn_to_rmap(vcpu->kvm, gfn, lpage);
        if (!*rmapp) {
                rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
                *rmapp = (unsigned long)spte;
@@ -436,20 +548,21 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
        struct kvm_rmap_desc *desc;
        struct kvm_rmap_desc *prev_desc;
        struct kvm_mmu_page *sp;
-       struct page *page;
+       pfn_t pfn;
        unsigned long *rmapp;
        int i;
 
        if (!is_rmap_pte(*spte))
                return;
        sp = page_header(__pa(spte));
-       page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
-       mark_page_accessed(page);
+       pfn = spte_to_pfn(*spte);
+       if (*spte & shadow_accessed_mask)
+               kvm_set_pfn_accessed(pfn);
        if (is_writeble_pte(*spte))
-               kvm_release_page_dirty(page);
+               kvm_release_pfn_dirty(pfn);
        else
-               kvm_release_page_clean(page);
-       rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt]);
+               kvm_release_pfn_clean(pfn);
+       rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt], is_large_pte(*spte));
        if (!*rmapp) {
                printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
                BUG();
@@ -515,7 +628,7 @@ static void rmap_write_protect(struct kvm *kvm, u64 gfn)
        int write_protected = 0;
 
        gfn = unalias_gfn(kvm, gfn);
-       rmapp = gfn_to_rmap(kvm, gfn);
+       rmapp = gfn_to_rmap(kvm, gfn, 0);
 
        spte = rmap_next(kvm, rmapp, NULL);
        while (spte) {
@@ -528,10 +641,118 @@ static void rmap_write_protect(struct kvm *kvm, u64 gfn)
                }
                spte = rmap_next(kvm, rmapp, spte);
        }
+       if (write_protected) {
+               pfn_t pfn;
+
+               spte = rmap_next(kvm, rmapp, NULL);
+               pfn = spte_to_pfn(*spte);
+               kvm_set_pfn_dirty(pfn);
+       }
+
+       /* check for huge page mappings */
+       rmapp = gfn_to_rmap(kvm, gfn, 1);
+       spte = rmap_next(kvm, rmapp, NULL);
+       while (spte) {
+               BUG_ON(!spte);
+               BUG_ON(!(*spte & PT_PRESENT_MASK));
+               BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK));
+               pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn);
+               if (is_writeble_pte(*spte)) {
+                       rmap_remove(kvm, spte);
+                       --kvm->stat.lpages;
+                       set_shadow_pte(spte, shadow_trap_nonpresent_pte);
+                       spte = NULL;
+                       write_protected = 1;
+               }
+               spte = rmap_next(kvm, rmapp, spte);
+       }
+
        if (write_protected)
                kvm_flush_remote_tlbs(kvm);
 }
 
+static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
+{
+       u64 *spte;
+       int need_tlb_flush = 0;
+
+       while ((spte = rmap_next(kvm, rmapp, NULL))) {
+               BUG_ON(!(*spte & PT_PRESENT_MASK));
+               rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte);
+               rmap_remove(kvm, spte);
+               set_shadow_pte(spte, shadow_trap_nonpresent_pte);
+               need_tlb_flush = 1;
+       }
+       return need_tlb_flush;
+}
+
+static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
+                         int (*handler)(struct kvm *kvm, unsigned long *rmapp))
+{
+       int i;
+       int retval = 0;
+
+       /*
+        * If mmap_sem isn't taken, we can look the memslots with only
+        * the mmu_lock by skipping over the slots with userspace_addr == 0.
+        */
+       for (i = 0; i < kvm->nmemslots; i++) {
+               struct kvm_memory_slot *memslot = &kvm->memslots[i];
+               unsigned long start = memslot->userspace_addr;
+               unsigned long end;
+
+               /* mmu_lock protects userspace_addr */
+               if (!start)
+                       continue;
+
+               end = start + (memslot->npages << PAGE_SHIFT);
+               if (hva >= start && hva < end) {
+                       gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
+                       retval |= handler(kvm, &memslot->rmap[gfn_offset]);
+                       retval |= handler(kvm,
+                                         &memslot->lpage_info[
+                                                 gfn_offset /
+                                                 KVM_PAGES_PER_HPAGE].rmap_pde);
+               }
+       }
+
+       return retval;
+}
+
+int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
+{
+       return kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
+}
+
+static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp)
+{
+       u64 *spte;
+       int young = 0;
+
+       /* always return old for EPT */
+       if (!shadow_accessed_mask)
+               return 0;
+
+       spte = rmap_next(kvm, rmapp, NULL);
+       while (spte) {
+               int _young;
+               u64 _spte = *spte;
+               BUG_ON(!(_spte & PT_PRESENT_MASK));
+               _young = _spte & PT_ACCESSED_MASK;
+               if (_young) {
+                       young = 1;
+                       clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
+               }
+               spte = rmap_next(kvm, rmapp, spte);
+       }
+       return young;
+}
+
+int kvm_age_hva(struct kvm *kvm, unsigned long hva)
+{
+       return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
+}
+
 #ifdef MMU_DEBUG
 static int is_empty_shadow_page(u64 *spt)
 {
@@ -539,8 +760,8 @@ static int is_empty_shadow_page(u64 *spt)
        u64 *end;
 
        for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
-               if (*pos != shadow_trap_nonpresent_pte) {
-                       printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__,
+               if (is_shadow_present_pte(*pos)) {
+                       printk(KERN_ERR "%s: %p %llx\n", __func__,
                               pos, *pos);
                        return 0;
                }
@@ -574,7 +795,7 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
        set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
        list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
        ASSERT(is_empty_shadow_page(sp->spt));
-       sp->slot_bitmap = 0;
+       bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
        sp->multimapped = 0;
        sp->parent_pte = parent_pte;
        --vcpu->kvm->arch.n_free_mmu_pages;
@@ -656,6 +877,138 @@ static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
        BUG();
 }
 
+
+static void mmu_parent_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
+                           mmu_parent_walk_fn fn)
+{
+       struct kvm_pte_chain *pte_chain;
+       struct hlist_node *node;
+       struct kvm_mmu_page *parent_sp;
+       int i;
+
+       if (!sp->multimapped && sp->parent_pte) {
+               parent_sp = page_header(__pa(sp->parent_pte));
+               fn(vcpu, parent_sp);
+               mmu_parent_walk(vcpu, parent_sp, fn);
+               return;
+       }
+       hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
+               for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
+                       if (!pte_chain->parent_ptes[i])
+                               break;
+                       parent_sp = page_header(__pa(pte_chain->parent_ptes[i]));
+                       fn(vcpu, parent_sp);
+                       mmu_parent_walk(vcpu, parent_sp, fn);
+               }
+}
+
+static void kvm_mmu_update_unsync_bitmap(u64 *spte)
+{
+       unsigned int index;
+       struct kvm_mmu_page *sp = page_header(__pa(spte));
+
+       index = spte - sp->spt;
+       __set_bit(index, sp->unsync_child_bitmap);
+       sp->unsync_children = 1;
+}
+
+static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page *sp)
+{
+       struct kvm_pte_chain *pte_chain;
+       struct hlist_node *node;
+       int i;
+
+       if (!sp->parent_pte)
+               return;
+
+       if (!sp->multimapped) {
+               kvm_mmu_update_unsync_bitmap(sp->parent_pte);
+               return;
+       }
+
+       hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
+               for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
+                       if (!pte_chain->parent_ptes[i])
+                               break;
+                       kvm_mmu_update_unsync_bitmap(pte_chain->parent_ptes[i]);
+               }
+}
+
+static int unsync_walk_fn(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+{
+       sp->unsync_children = 1;
+       kvm_mmu_update_parents_unsync(sp);
+       return 1;
+}
+
+static void kvm_mmu_mark_parents_unsync(struct kvm_vcpu *vcpu,
+                                       struct kvm_mmu_page *sp)
+{
+       mmu_parent_walk(vcpu, sp, unsync_walk_fn);
+       kvm_mmu_update_parents_unsync(sp);
+}
+
+static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
+                                   struct kvm_mmu_page *sp)
+{
+       int i;
+
+       for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
+               sp->spt[i] = shadow_trap_nonpresent_pte;
+}
+
+static int nonpaging_sync_page(struct kvm_vcpu *vcpu,
+                              struct kvm_mmu_page *sp)
+{
+       return 1;
+}
+
+static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
+{
+}
+
+#define for_each_unsync_children(bitmap, idx)          \
+       for (idx = find_first_bit(bitmap, 512);         \
+            idx < 512;                                 \
+            idx = find_next_bit(bitmap, 512, idx+1))
+
+static int mmu_unsync_walk(struct kvm_mmu_page *sp,
+                          struct kvm_unsync_walk *walker)
+{
+       int i, ret;
+
+       if (!sp->unsync_children)
+               return 0;
+
+       for_each_unsync_children(sp->unsync_child_bitmap, i) {
+               u64 ent = sp->spt[i];
+
+               if (is_shadow_present_pte(ent)) {
+                       struct kvm_mmu_page *child;
+                       child = page_header(ent & PT64_BASE_ADDR_MASK);
+
+                       if (child->unsync_children) {
+                               ret = mmu_unsync_walk(child, walker);
+                               if (ret)
+                                       return ret;
+                               __clear_bit(i, sp->unsync_child_bitmap);
+                       }
+
+                       if (child->unsync) {
+                               ret = walker->entry(child, walker);
+                               __clear_bit(i, sp->unsync_child_bitmap);
+                               if (ret)
+                                       return ret;
+                       }
+               }
+       }
+
+       if (find_first_bit(sp->unsync_child_bitmap, 512) == 512)
+               sp->unsync_children = 0;
+
+       return 0;
+}
+
 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
 {
        unsigned index;
@@ -663,18 +1016,72 @@ static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
        struct kvm_mmu_page *sp;
        struct hlist_node *node;
 
-       pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
+       pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
        index = kvm_page_table_hashfn(gfn);
        bucket = &kvm->arch.mmu_page_hash[index];
        hlist_for_each_entry(sp, node, bucket, hash_link)
-               if (sp->gfn == gfn && !sp->role.metaphysical) {
+               if (sp->gfn == gfn && !sp->role.metaphysical
+                   && !sp->role.invalid) {
                        pgprintk("%s: found role %x\n",
-                                __FUNCTION__, sp->role.word);
+                                __func__, sp->role.word);
                        return sp;
                }
        return NULL;
 }
 
+static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
+{
+       WARN_ON(!sp->unsync);
+       sp->unsync = 0;
+       --kvm->stat.mmu_unsync;
+}
+
+static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp);
+
+static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+{
+       if (sp->role.glevels != vcpu->arch.mmu.root_level) {
+               kvm_mmu_zap_page(vcpu->kvm, sp);
+               return 1;
+       }
+
+       rmap_write_protect(vcpu->kvm, sp->gfn);
+       kvm_unlink_unsync_page(vcpu->kvm, sp);
+       if (vcpu->arch.mmu.sync_page(vcpu, sp)) {
+               kvm_mmu_zap_page(vcpu->kvm, sp);
+               return 1;
+       }
+
+       kvm_mmu_flush_tlb(vcpu);
+       return 0;
+}
+
+struct sync_walker {
+       struct kvm_vcpu *vcpu;
+       struct kvm_unsync_walk walker;
+};
+
+static int mmu_sync_fn(struct kvm_mmu_page *sp, struct kvm_unsync_walk *walk)
+{
+       struct sync_walker *sync_walk = container_of(walk, struct sync_walker,
+                                                    walker);
+       struct kvm_vcpu *vcpu = sync_walk->vcpu;
+
+       kvm_sync_page(vcpu, sp);
+       return (need_resched() || spin_needbreak(&vcpu->kvm->mmu_lock));
+}
+
+static void mmu_sync_children(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+{
+       struct sync_walker walker = {
+               .walker = { .entry = mmu_sync_fn, },
+               .vcpu = vcpu,
+       };
+
+       while (mmu_unsync_walk(sp, &walker.walker))
+               cond_resched_lock(&vcpu->kvm->mmu_lock);
+}
+
 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
                                             gfn_t gfn,
                                             gva_t gaddr,
@@ -688,7 +1095,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
        unsigned quadrant;
        struct hlist_head *bucket;
        struct kvm_mmu_page *sp;
-       struct hlist_node *node;
+       struct hlist_node *node, *tmp;
 
        role.word = 0;
        role.glevels = vcpu->arch.mmu.root_level;
@@ -700,30 +1107,75 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
                quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
                role.quadrant = quadrant;
        }
-       pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__,
+       pgprintk("%s: looking gfn %lx role %x\n", __func__,
                 gfn, role.word);
        index = kvm_page_table_hashfn(gfn);
        bucket = &vcpu->kvm->arch.mmu_page_hash[index];
-       hlist_for_each_entry(sp, node, bucket, hash_link)
-               if (sp->gfn == gfn && sp->role.word == role.word) {
+       hlist_for_each_entry_safe(sp, node, tmp, bucket, hash_link)
+               if (sp->gfn == gfn) {
+                       if (sp->unsync)
+                               if (kvm_sync_page(vcpu, sp))
+                                       continue;
+
+                       if (sp->role.word != role.word)
+                               continue;
+
                        mmu_page_add_parent_pte(vcpu, sp, parent_pte);
-                       pgprintk("%s: found\n", __FUNCTION__);
+                       if (sp->unsync_children) {
+                               set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests);
+                               kvm_mmu_mark_parents_unsync(vcpu, sp);
+                       }
+                       pgprintk("%s: found\n", __func__);
                        return sp;
                }
        ++vcpu->kvm->stat.mmu_cache_miss;
        sp = kvm_mmu_alloc_page(vcpu, parent_pte);
        if (!sp)
                return sp;
-       pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__, gfn, role.word);
+       pgprintk("%s: adding gfn %lx role %x\n", __func__, gfn, role.word);
        sp->gfn = gfn;
        sp->role = role;
        hlist_add_head(&sp->hash_link, bucket);
-       vcpu->arch.mmu.prefetch_page(vcpu, sp);
-       if (!metaphysical)
+       if (!metaphysical) {
                rmap_write_protect(vcpu->kvm, gfn);
+               account_shadowed(vcpu->kvm, gfn);
+       }
+       if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte)
+               vcpu->arch.mmu.prefetch_page(vcpu, sp);
+       else
+               nonpaging_prefetch_page(vcpu, sp);
        return sp;
 }
 
+static int walk_shadow(struct kvm_shadow_walk *walker,
+                      struct kvm_vcpu *vcpu, u64 addr)
+{
+       hpa_t shadow_addr;
+       int level;
+       int r;
+       u64 *sptep;
+       unsigned index;
+
+       shadow_addr = vcpu->arch.mmu.root_hpa;
+       level = vcpu->arch.mmu.shadow_root_level;
+       if (level == PT32E_ROOT_LEVEL) {
+               shadow_addr = vcpu->arch.mmu.pae_root[(addr >> 30) & 3];
+               shadow_addr &= PT64_BASE_ADDR_MASK;
+               --level;
+       }
+
+       while (level >= PT_PAGE_TABLE_LEVEL) {
+               index = SHADOW_PT_INDEX(addr, level);
+               sptep = ((u64 *)__va(shadow_addr)) + index;
+               r = walker->entry(walker, vcpu, addr, sptep, level);
+               if (r)
+                       return r;
+               shadow_addr = *sptep & PT64_BASE_ADDR_MASK;
+               --level;
+       }
+       return 0;
+}
+
 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
                                         struct kvm_mmu_page *sp)
 {
@@ -739,20 +1191,24 @@ static void kvm_mmu_page_unlink_children(struct kvm *kvm,
                                rmap_remove(kvm, &pt[i]);
                        pt[i] = shadow_trap_nonpresent_pte;
                }
-               kvm_flush_remote_tlbs(kvm);
                return;
        }
 
        for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
                ent = pt[i];
 
+               if (is_shadow_present_pte(ent)) {
+                       if (!is_large_pte(ent)) {
+                               ent &= PT64_BASE_ADDR_MASK;
+                               mmu_page_remove_parent_pte(page_header(ent),
+                                                          &pt[i]);
+                       } else {
+                               --kvm->stat.lpages;
+                               rmap_remove(kvm, &pt[i]);
+                       }
+               }
                pt[i] = shadow_trap_nonpresent_pte;
-               if (!is_shadow_present_pte(ent))
-                       continue;
-               ent &= PT64_BASE_ADDR_MASK;
-               mmu_page_remove_parent_pte(page_header(ent), &pt[i]);
        }
-       kvm_flush_remote_tlbs(kvm);
 }
 
 static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
@@ -769,11 +1225,10 @@ static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm)
                        kvm->vcpus[i]->arch.last_pte_updated = NULL;
 }
 
-static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
+static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
        u64 *parent_pte;
 
-       ++kvm->stat.mmu_shadow_zapped;
        while (sp->multimapped || sp->parent_pte) {
                if (!sp->multimapped)
                        parent_pte = sp->parent_pte;
@@ -788,13 +1243,59 @@ static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
                kvm_mmu_put_page(sp, parent_pte);
                set_shadow_pte(parent_pte, shadow_trap_nonpresent_pte);
        }
+}
+
+struct zap_walker {
+       struct kvm_unsync_walk walker;
+       struct kvm *kvm;
+       int zapped;
+};
+
+static int mmu_zap_fn(struct kvm_mmu_page *sp, struct kvm_unsync_walk *walk)
+{
+       struct zap_walker *zap_walk = container_of(walk, struct zap_walker,
+                                                    walker);
+       kvm_mmu_zap_page(zap_walk->kvm, sp);
+       zap_walk->zapped = 1;
+       return 0;
+}
+
+static int mmu_zap_unsync_children(struct kvm *kvm, struct kvm_mmu_page *sp)
+{
+       struct zap_walker walker = {
+               .walker = { .entry = mmu_zap_fn, },
+               .kvm = kvm,
+               .zapped = 0,
+       };
+
+       if (sp->role.level == PT_PAGE_TABLE_LEVEL)
+               return 0;
+       mmu_unsync_walk(sp, &walker.walker);
+       return walker.zapped;
+}
+
+static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
+{
+       int ret;
+       ++kvm->stat.mmu_shadow_zapped;
+       ret = mmu_zap_unsync_children(kvm, sp);
        kvm_mmu_page_unlink_children(kvm, sp);
+       kvm_mmu_unlink_parents(kvm, sp);
+       kvm_flush_remote_tlbs(kvm);
+       if (!sp->role.invalid && !sp->role.metaphysical)
+               unaccount_shadowed(kvm, sp->gfn);
+       if (sp->unsync)
+               kvm_unlink_unsync_page(kvm, sp);
        if (!sp->root_count) {
                hlist_del(&sp->hash_link);
                kvm_mmu_free_page(kvm, sp);
-       } else
+       } else {
+               sp->role.invalid = 1;
                list_move(&sp->link, &kvm->arch.active_mmu_pages);
+               kvm_reload_remote_mmus(kvm);
+       }
        kvm_mmu_reset_last_pte_updated(kvm);
+       return ret;
 }
 
 /*
@@ -839,16 +1340,17 @@ static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
        struct hlist_node *node, *n;
        int r;
 
-       pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
+       pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
        r = 0;
        index = kvm_page_table_hashfn(gfn);
        bucket = &kvm->arch.mmu_page_hash[index];
        hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
                if (sp->gfn == gfn && !sp->role.metaphysical) {
-                       pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn,
+                       pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
                                 sp->role.word);
-                       kvm_mmu_zap_page(kvm, sp);
                        r = 1;
+                       if (kvm_mmu_zap_page(kvm, sp))
+                               n = bucket->first;
                }
        return r;
 }
@@ -858,7 +1360,7 @@ static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
        struct kvm_mmu_page *sp;
 
        while ((sp = kvm_mmu_lookup_page(kvm, gfn)) != NULL) {
-               pgprintk("%s: zap %lx %x\n", __FUNCTION__, gfn, sp->role.word);
+               pgprintk("%s: zap %lx %x\n", __func__, gfn, sp->role.word);
                kvm_mmu_zap_page(kvm, sp);
        }
 }
@@ -868,7 +1370,21 @@ static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
        int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
        struct kvm_mmu_page *sp = page_header(__pa(pte));
 
-       __set_bit(slot, &sp->slot_bitmap);
+       __set_bit(slot, sp->slot_bitmap);
+}
+
+static void mmu_convert_notrap(struct kvm_mmu_page *sp)
+{
+       int i;
+       u64 *pt = sp->spt;
+
+       if (shadow_trap_nonpresent_pte == shadow_notrap_nonpresent_pte)
+               return;
+
+       for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
+               if (pt[i] == shadow_notrap_nonpresent_pte)
+                       set_shadow_pte(&pt[i], shadow_trap_nonpresent_pte);
+       }
 }
 
 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
@@ -880,186 +1396,404 @@ struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
        if (gpa == UNMAPPED_GVA)
                return NULL;
 
-       down_read(&current->mm->mmap_sem);
        page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
-       up_read(&current->mm->mmap_sem);
 
        return page;
 }
 
+/*
+ * The function is based on mtrr_type_lookup() in
+ * arch/x86/kernel/cpu/mtrr/generic.c
+ */
+static int get_mtrr_type(struct mtrr_state_type *mtrr_state,
+                        u64 start, u64 end)
+{
+       int i;
+       u64 base, mask;
+       u8 prev_match, curr_match;
+       int num_var_ranges = KVM_NR_VAR_MTRR;
+
+       if (!mtrr_state->enabled)
+               return 0xFF;
+
+       /* Make end inclusive end, instead of exclusive */
+       end--;
+
+       /* Look in fixed ranges. Just return the type as per start */
+       if (mtrr_state->have_fixed && (start < 0x100000)) {
+               int idx;
+
+               if (start < 0x80000) {
+                       idx = 0;
+                       idx += (start >> 16);
+                       return mtrr_state->fixed_ranges[idx];
+               } else if (start < 0xC0000) {
+                       idx = 1 * 8;
+                       idx += ((start - 0x80000) >> 14);
+                       return mtrr_state->fixed_ranges[idx];
+               } else if (start < 0x1000000) {
+                       idx = 3 * 8;
+                       idx += ((start - 0xC0000) >> 12);
+                       return mtrr_state->fixed_ranges[idx];
+               }
+       }
+
+       /*
+        * Look in variable ranges
+        * Look of multiple ranges matching this address and pick type
+        * as per MTRR precedence
+        */
+       if (!(mtrr_state->enabled & 2))
+               return mtrr_state->def_type;
+
+       prev_match = 0xFF;
+       for (i = 0; i < num_var_ranges; ++i) {
+               unsigned short start_state, end_state;
+
+               if (!(mtrr_state->var_ranges[i].mask_lo & (1 << 11)))
+                       continue;
+
+               base = (((u64)mtrr_state->var_ranges[i].base_hi) << 32) +
+                      (mtrr_state->var_ranges[i].base_lo & PAGE_MASK);
+               mask = (((u64)mtrr_state->var_ranges[i].mask_hi) << 32) +
+                      (mtrr_state->var_ranges[i].mask_lo & PAGE_MASK);
+
+               start_state = ((start & mask) == (base & mask));
+               end_state = ((end & mask) == (base & mask));
+               if (start_state != end_state)
+                       return 0xFE;
+
+               if ((start & mask) != (base & mask))
+                       continue;
+
+               curr_match = mtrr_state->var_ranges[i].base_lo & 0xff;
+               if (prev_match == 0xFF) {
+                       prev_match = curr_match;
+                       continue;
+               }
+
+               if (prev_match == MTRR_TYPE_UNCACHABLE ||
+                   curr_match == MTRR_TYPE_UNCACHABLE)
+                       return MTRR_TYPE_UNCACHABLE;
+
+               if ((prev_match == MTRR_TYPE_WRBACK &&
+                    curr_match == MTRR_TYPE_WRTHROUGH) ||
+                   (prev_match == MTRR_TYPE_WRTHROUGH &&
+                    curr_match == MTRR_TYPE_WRBACK)) {
+                       prev_match = MTRR_TYPE_WRTHROUGH;
+                       curr_match = MTRR_TYPE_WRTHROUGH;
+               }
+
+               if (prev_match != curr_match)
+                       return MTRR_TYPE_UNCACHABLE;
+       }
+
+       if (prev_match != 0xFF)
+               return prev_match;
+
+       return mtrr_state->def_type;
+}
+
+static u8 get_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+       u8 mtrr;
+
+       mtrr = get_mtrr_type(&vcpu->arch.mtrr_state, gfn << PAGE_SHIFT,
+                            (gfn << PAGE_SHIFT) + PAGE_SIZE);
+       if (mtrr == 0xfe || mtrr == 0xff)
+               mtrr = MTRR_TYPE_WRBACK;
+       return mtrr;
+}
+
+static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+{
+       unsigned index;
+       struct hlist_head *bucket;
+       struct kvm_mmu_page *s;
+       struct hlist_node *node, *n;
+
+       index = kvm_page_table_hashfn(sp->gfn);
+       bucket = &vcpu->kvm->arch.mmu_page_hash[index];
+       /* don't unsync if pagetable is shadowed with multiple roles */
+       hlist_for_each_entry_safe(s, node, n, bucket, hash_link) {
+               if (s->gfn != sp->gfn || s->role.metaphysical)
+                       continue;
+               if (s->role.word != sp->role.word)
+                       return 1;
+       }
+       kvm_mmu_mark_parents_unsync(vcpu, sp);
+       ++vcpu->kvm->stat.mmu_unsync;
+       sp->unsync = 1;
+       mmu_convert_notrap(sp);
+       return 0;
+}
+
+static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
+                                 bool can_unsync)
+{
+       struct kvm_mmu_page *shadow;
+
+       shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
+       if (shadow) {
+               if (shadow->role.level != PT_PAGE_TABLE_LEVEL)
+                       return 1;
+               if (shadow->unsync)
+                       return 0;
+               if (can_unsync && oos_shadow)
+                       return kvm_unsync_page(vcpu, shadow);
+               return 1;
+       }
+       return 0;
+}
+
+static int set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
+                   unsigned pte_access, int user_fault,
+                   int write_fault, int dirty, int largepage,
+                   gfn_t gfn, pfn_t pfn, bool speculative,
+                   bool can_unsync)
+{
+       u64 spte;
+       int ret = 0;
+       u64 mt_mask = shadow_mt_mask;
+
+       /*
+        * We don't set the accessed bit, since we sometimes want to see
+        * whether the guest actually used the pte (in order to detect
+        * demand paging).
+        */
+       spte = shadow_base_present_pte | shadow_dirty_mask;
+       if (!speculative)
+               spte |= shadow_accessed_mask;
+       if (!dirty)
+               pte_access &= ~ACC_WRITE_MASK;
+       if (pte_access & ACC_EXEC_MASK)
+               spte |= shadow_x_mask;
+       else
+               spte |= shadow_nx_mask;
+       if (pte_access & ACC_USER_MASK)
+               spte |= shadow_user_mask;
+       if (largepage)
+               spte |= PT_PAGE_SIZE_MASK;
+       if (mt_mask) {
+               mt_mask = get_memory_type(vcpu, gfn) <<
+                         kvm_x86_ops->get_mt_mask_shift();
+               spte |= mt_mask;
+       }
+
+       spte |= (u64)pfn << PAGE_SHIFT;
+
+       if ((pte_access & ACC_WRITE_MASK)
+           || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
+
+               if (largepage && has_wrprotected_page(vcpu->kvm, gfn)) {
+                       ret = 1;
+                       spte = shadow_trap_nonpresent_pte;
+                       goto set_pte;
+               }
+
+               spte |= PT_WRITABLE_MASK;
+
+               /*
+                * Optimization: for pte sync, if spte was writable the hash
+                * lookup is unnecessary (and expensive). Write protection
+                * is responsibility of mmu_get_page / kvm_sync_page.
+                * Same reasoning can be applied to dirty page accounting.
+                */
+               if (!can_unsync && is_writeble_pte(*shadow_pte))
+                       goto set_pte;
+
+               if (mmu_need_write_protect(vcpu, gfn, can_unsync)) {
+                       pgprintk("%s: found shadow page for %lx, marking ro\n",
+                                __func__, gfn);
+                       ret = 1;
+                       pte_access &= ~ACC_WRITE_MASK;
+                       if (is_writeble_pte(spte))
+                               spte &= ~PT_WRITABLE_MASK;
+               }
+       }
+
+       if (pte_access & ACC_WRITE_MASK)
+               mark_page_dirty(vcpu->kvm, gfn);
+
+set_pte:
+       set_shadow_pte(shadow_pte, spte);
+       return ret;
+}
+
 static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
                         unsigned pt_access, unsigned pte_access,
                         int user_fault, int write_fault, int dirty,
-                        int *ptwrite, gfn_t gfn, struct page *page)
+                        int *ptwrite, int largepage, gfn_t gfn,
+                        pfn_t pfn, bool speculative)
 {
-       u64 spte;
        int was_rmapped = 0;
        int was_writeble = is_writeble_pte(*shadow_pte);
-       hfn_t host_pfn = (*shadow_pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
 
        pgprintk("%s: spte %llx access %x write_fault %d"
                 " user_fault %d gfn %lx\n",
-                __FUNCTION__, *shadow_pte, pt_access,
+                __func__, *shadow_pte, pt_access,
                 write_fault, user_fault, gfn);
 
        if (is_rmap_pte(*shadow_pte)) {
-               if (host_pfn != page_to_pfn(page)) {
+               /*
+                * If we overwrite a PTE page pointer with a 2MB PMD, unlink
+                * the parent of the now unreachable PTE.
+                */
+               if (largepage && !is_large_pte(*shadow_pte)) {
+                       struct kvm_mmu_page *child;
+                       u64 pte = *shadow_pte;
+
+                       child = page_header(pte & PT64_BASE_ADDR_MASK);
+                       mmu_page_remove_parent_pte(child, shadow_pte);
+               } else if (pfn != spte_to_pfn(*shadow_pte)) {
                        pgprintk("hfn old %lx new %lx\n",
-                                host_pfn, page_to_pfn(page));
+                                spte_to_pfn(*shadow_pte), pfn);
                        rmap_remove(vcpu->kvm, shadow_pte);
+               } else {
+                       if (largepage)
+                               was_rmapped = is_large_pte(*shadow_pte);
+                       else
+                               was_rmapped = 1;
                }
-               else
-                       was_rmapped = 1;
        }
-
-       /*
-        * We don't set the accessed bit, since we sometimes want to see
-        * whether the guest actually used the pte (in order to detect
-        * demand paging).
-        */
-       spte = PT_PRESENT_MASK | PT_DIRTY_MASK;
-       if (!dirty)
-               pte_access &= ~ACC_WRITE_MASK;
-       if (!(pte_access & ACC_EXEC_MASK))
-               spte |= PT64_NX_MASK;
-
-       spte |= PT_PRESENT_MASK;
-       if (pte_access & ACC_USER_MASK)
-               spte |= PT_USER_MASK;
-
-       spte |= page_to_phys(page);
-
-       if ((pte_access & ACC_WRITE_MASK)
-           || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
-               struct kvm_mmu_page *shadow;
-
-               spte |= PT_WRITABLE_MASK;
-               if (user_fault) {
-                       mmu_unshadow(vcpu->kvm, gfn);
-                       goto unshadowed;
-               }
-
-               shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
-               if (shadow) {
-                       pgprintk("%s: found shadow page for %lx, marking ro\n",
-                                __FUNCTION__, gfn);
-                       pte_access &= ~ACC_WRITE_MASK;
-                       if (is_writeble_pte(spte)) {
-                               spte &= ~PT_WRITABLE_MASK;
-                               kvm_x86_ops->tlb_flush(vcpu);
-                       }
-                       if (write_fault)
-                               *ptwrite = 1;
-               }
+       if (set_spte(vcpu, shadow_pte, pte_access, user_fault, write_fault,
+                     dirty, largepage, gfn, pfn, speculative, true)) {
+               if (write_fault)
+                       *ptwrite = 1;
+               kvm_x86_ops->tlb_flush(vcpu);
        }
 
-unshadowed:
+       pgprintk("%s: setting spte %llx\n", __func__, *shadow_pte);
+       pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
+                is_large_pte(*shadow_pte)? "2MB" : "4kB",
+                is_present_pte(*shadow_pte)?"RW":"R", gfn,
+                *shadow_pte, shadow_pte);
+       if (!was_rmapped && is_large_pte(*shadow_pte))
+               ++vcpu->kvm->stat.lpages;
 
-       if (pte_access & ACC_WRITE_MASK)
-               mark_page_dirty(vcpu->kvm, gfn);
-
-       pgprintk("%s: setting spte %llx\n", __FUNCTION__, spte);
-       set_shadow_pte(shadow_pte, spte);
        page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
        if (!was_rmapped) {
-               rmap_add(vcpu, shadow_pte, gfn);
+               rmap_add(vcpu, shadow_pte, gfn, largepage);
                if (!is_rmap_pte(*shadow_pte))
-                       kvm_release_page_clean(page);
+                       kvm_release_pfn_clean(pfn);
        } else {
                if (was_writeble)
-                       kvm_release_page_dirty(page);
+                       kvm_release_pfn_dirty(pfn);
                else
-                       kvm_release_page_clean(page);
+                       kvm_release_pfn_clean(pfn);
        }
-       if (!ptwrite || !*ptwrite)
+       if (speculative) {
                vcpu->arch.last_pte_updated = shadow_pte;
+               vcpu->arch.last_pte_gfn = gfn;
+       }
 }
 
 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
 {
 }
 
-static int __nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write,
-                          gfn_t gfn, struct page *page)
-{
-       int level = PT32E_ROOT_LEVEL;
-       hpa_t table_addr = vcpu->arch.mmu.root_hpa;
-       int pt_write = 0;
-
-       for (; ; level--) {
-               u32 index = PT64_INDEX(v, level);
-               u64 *table;
+struct direct_shadow_walk {
+       struct kvm_shadow_walk walker;
+       pfn_t pfn;
+       int write;
+       int largepage;
+       int pt_write;
+};
 
-               ASSERT(VALID_PAGE(table_addr));
-               table = __va(table_addr);
+static int direct_map_entry(struct kvm_shadow_walk *_walk,
+                           struct kvm_vcpu *vcpu,
+                           u64 addr, u64 *sptep, int level)
+{
+       struct direct_shadow_walk *walk =
+               container_of(_walk, struct direct_shadow_walk, walker);
+       struct kvm_mmu_page *sp;
+       gfn_t pseudo_gfn;
+       gfn_t gfn = addr >> PAGE_SHIFT;
+
+       if (level == PT_PAGE_TABLE_LEVEL
+           || (walk->largepage && level == PT_DIRECTORY_LEVEL)) {
+               mmu_set_spte(vcpu, sptep, ACC_ALL, ACC_ALL,
+                            0, walk->write, 1, &walk->pt_write,
+                            walk->largepage, gfn, walk->pfn, false);
+               ++vcpu->stat.pf_fixed;
+               return 1;
+       }
 
-               if (level == 1) {
-                       mmu_set_spte(vcpu, &table[index], ACC_ALL, ACC_ALL,
-                                    0, write, 1, &pt_write, gfn, page);
-                       return pt_write;
+       if (*sptep == shadow_trap_nonpresent_pte) {
+               pseudo_gfn = (addr & PT64_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
+               sp = kvm_mmu_get_page(vcpu, pseudo_gfn, (gva_t)addr, level - 1,
+                                     1, ACC_ALL, sptep);
+               if (!sp) {
+                       pgprintk("nonpaging_map: ENOMEM\n");
+                       kvm_release_pfn_clean(walk->pfn);
+                       return -ENOMEM;
                }
 
-               if (table[index] == shadow_trap_nonpresent_pte) {
-                       struct kvm_mmu_page *new_table;
-                       gfn_t pseudo_gfn;
-
-                       pseudo_gfn = (v & PT64_DIR_BASE_ADDR_MASK)
-                               >> PAGE_SHIFT;
-                       new_table = kvm_mmu_get_page(vcpu, pseudo_gfn,
-                                                    v, level - 1,
-                                                    1, ACC_ALL, &table[index]);
-                       if (!new_table) {
-                               pgprintk("nonpaging_map: ENOMEM\n");
-                               kvm_release_page_clean(page);
-                               return -ENOMEM;
-                       }
-
-                       table[index] = __pa(new_table->spt) | PT_PRESENT_MASK
-                               | PT_WRITABLE_MASK | PT_USER_MASK;
-               }
-               table_addr = table[index] & PT64_BASE_ADDR_MASK;
+               set_shadow_pte(sptep,
+                              __pa(sp->spt)
+                              | PT_PRESENT_MASK | PT_WRITABLE_MASK
+                              | shadow_user_mask | shadow_x_mask);
        }
+       return 0;
 }
 
-static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
+static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
+                       int largepage, gfn_t gfn, pfn_t pfn)
 {
        int r;
+       struct direct_shadow_walk walker = {
+               .walker = { .entry = direct_map_entry, },
+               .pfn = pfn,
+               .largepage = largepage,
+               .write = write,
+               .pt_write = 0,
+       };
+
+       r = walk_shadow(&walker.walker, vcpu, gfn << PAGE_SHIFT);
+       if (r < 0)
+               return r;
+       return walker.pt_write;
+}
 
-       struct page *page;
+static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
+{
+       int r;
+       int largepage = 0;
+       pfn_t pfn;
+       unsigned long mmu_seq;
 
-       down_read(&vcpu->kvm->slots_lock);
+       if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) {
+               gfn &= ~(KVM_PAGES_PER_HPAGE-1);
+               largepage = 1;
+       }
 
-       down_read(&current->mm->mmap_sem);
-       page = gfn_to_page(vcpu->kvm, gfn);
-       up_read(&current->mm->mmap_sem);
+       mmu_seq = vcpu->kvm->mmu_notifier_seq;
+       smp_rmb();
+       pfn = gfn_to_pfn(vcpu->kvm, gfn);
 
        /* mmio */
-       if (is_error_page(page)) {
-               kvm_release_page_clean(page);
-               up_read(&vcpu->kvm->slots_lock);
+       if (is_error_pfn(pfn)) {
+               kvm_release_pfn_clean(pfn);
                return 1;
        }
 
        spin_lock(&vcpu->kvm->mmu_lock);
+       if (mmu_notifier_retry(vcpu, mmu_seq))
+               goto out_unlock;
        kvm_mmu_free_some_pages(vcpu);
-       r = __nonpaging_map(vcpu, v, write, gfn, page);
+       r = __direct_map(vcpu, v, write, largepage, gfn, pfn);
        spin_unlock(&vcpu->kvm->mmu_lock);
 
-       up_read(&vcpu->kvm->slots_lock);
 
        return r;
-}
-
-
-static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
-                                   struct kvm_mmu_page *sp)
-{
-       int i;
 
-       for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
-               sp->spt[i] = shadow_trap_nonpresent_pte;
+out_unlock:
+       spin_unlock(&vcpu->kvm->mmu_lock);
+       kvm_release_pfn_clean(pfn);
+       return 0;
 }
 
+
 static void mmu_free_roots(struct kvm_vcpu *vcpu)
 {
        int i;
@@ -1068,17 +1802,17 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu)
        if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
                return;
        spin_lock(&vcpu->kvm->mmu_lock);
-#ifdef CONFIG_X86_64
        if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
                hpa_t root = vcpu->arch.mmu.root_hpa;
 
                sp = page_header(root);
                --sp->root_count;
+               if (!sp->root_count && sp->role.invalid)
+                       kvm_mmu_zap_page(vcpu->kvm, sp);
                vcpu->arch.mmu.root_hpa = INVALID_PAGE;
                spin_unlock(&vcpu->kvm->mmu_lock);
                return;
        }
-#endif
        for (i = 0; i < 4; ++i) {
                hpa_t root = vcpu->arch.mmu.pae_root[i];
 
@@ -1086,6 +1820,8 @@ static void mmu_free_roots(struct kvm_vcpu *vcpu)
                        root &= PT64_BASE_ADDR_MASK;
                        sp = page_header(root);
                        --sp->root_count;
+                       if (!sp->root_count && sp->role.invalid)
+                               kvm_mmu_zap_page(vcpu->kvm, sp);
                }
                vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
        }
@@ -1098,22 +1834,27 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
        int i;
        gfn_t root_gfn;
        struct kvm_mmu_page *sp;
+       int metaphysical = 0;
 
        root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
 
-#ifdef CONFIG_X86_64
        if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
                hpa_t root = vcpu->arch.mmu.root_hpa;
 
                ASSERT(!VALID_PAGE(root));
+               if (tdp_enabled)
+                       metaphysical = 1;
                sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
-                                     PT64_ROOT_LEVEL, 0, ACC_ALL, NULL);
+                                     PT64_ROOT_LEVEL, metaphysical,
+                                     ACC_ALL, NULL);
                root = __pa(sp->spt);
                ++sp->root_count;
                vcpu->arch.mmu.root_hpa = root;
                return;
        }
-#endif
+       metaphysical = !is_paging(vcpu);
+       if (tdp_enabled)
+               metaphysical = 1;
        for (i = 0; i < 4; ++i) {
                hpa_t root = vcpu->arch.mmu.pae_root[i];
 
@@ -1127,7 +1868,7 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
                } else if (vcpu->arch.mmu.root_level == 0)
                        root_gfn = 0;
                sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
-                                     PT32_ROOT_LEVEL, !is_paging(vcpu),
+                                     PT32_ROOT_LEVEL, metaphysical,
                                      ACC_ALL, NULL);
                root = __pa(sp->spt);
                ++sp->root_count;
@@ -1136,6 +1877,37 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
        vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
 }
 
+static void mmu_sync_roots(struct kvm_vcpu *vcpu)
+{
+       int i;
+       struct kvm_mmu_page *sp;
+
+       if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
+               return;
+       if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
+               hpa_t root = vcpu->arch.mmu.root_hpa;
+               sp = page_header(root);
+               mmu_sync_children(vcpu, sp);
+               return;
+       }
+       for (i = 0; i < 4; ++i) {
+               hpa_t root = vcpu->arch.mmu.pae_root[i];
+
+               if (root) {
+                       root &= PT64_BASE_ADDR_MASK;
+                       sp = page_header(root);
+                       mmu_sync_children(vcpu, sp);
+               }
+       }
+}
+
+void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
+{
+       spin_lock(&vcpu->kvm->mmu_lock);
+       mmu_sync_roots(vcpu);
+       spin_unlock(&vcpu->kvm->mmu_lock);
+}
+
 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
 {
        return vaddr;
@@ -1147,7 +1919,7 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
        gfn_t gfn;
        int r;
 
-       pgprintk("%s: gva %lx error %x\n", __FUNCTION__, gva, error_code);
+       pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code);
        r = mmu_topup_memory_caches(vcpu);
        if (r)
                return r;
@@ -1161,6 +1933,49 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
                             error_code & PFERR_WRITE_MASK, gfn);
 }
 
+static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
+                               u32 error_code)
+{
+       pfn_t pfn;
+       int r;
+       int largepage = 0;
+       gfn_t gfn = gpa >> PAGE_SHIFT;
+       unsigned long mmu_seq;
+
+       ASSERT(vcpu);
+       ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
+
+       r = mmu_topup_memory_caches(vcpu);
+       if (r)
+               return r;
+
+       if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) {
+               gfn &= ~(KVM_PAGES_PER_HPAGE-1);
+               largepage = 1;
+       }
+       mmu_seq = vcpu->kvm->mmu_notifier_seq;
+       smp_rmb();
+       pfn = gfn_to_pfn(vcpu->kvm, gfn);
+       if (is_error_pfn(pfn)) {
+               kvm_release_pfn_clean(pfn);
+               return 1;
+       }
+       spin_lock(&vcpu->kvm->mmu_lock);
+       if (mmu_notifier_retry(vcpu, mmu_seq))
+               goto out_unlock;
+       kvm_mmu_free_some_pages(vcpu);
+       r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK,
+                        largepage, gfn, pfn);
+       spin_unlock(&vcpu->kvm->mmu_lock);
+
+       return r;
+
+out_unlock:
+       spin_unlock(&vcpu->kvm->mmu_lock);
+       kvm_release_pfn_clean(pfn);
+       return 0;
+}
+
 static void nonpaging_free(struct kvm_vcpu *vcpu)
 {
        mmu_free_roots(vcpu);
@@ -1175,6 +1990,8 @@ static int nonpaging_init_context(struct kvm_vcpu *vcpu)
        context->gva_to_gpa = nonpaging_gva_to_gpa;
        context->free = nonpaging_free;
        context->prefetch_page = nonpaging_prefetch_page;
+       context->sync_page = nonpaging_sync_page;
+       context->invlpg = nonpaging_invlpg;
        context->root_level = 0;
        context->shadow_root_level = PT32E_ROOT_LEVEL;
        context->root_hpa = INVALID_PAGE;
@@ -1189,7 +2006,7 @@ void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
 
 static void paging_new_cr3(struct kvm_vcpu *vcpu)
 {
-       pgprintk("%s: cr3 %lx\n", __FUNCTION__, vcpu->arch.cr3);
+       pgprintk("%s: cr3 %lx\n", __func__, vcpu->arch.cr3);
        mmu_free_roots(vcpu);
 }
 
@@ -1222,6 +2039,8 @@ static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
        context->page_fault = paging64_page_fault;
        context->gva_to_gpa = paging64_gva_to_gpa;
        context->prefetch_page = paging64_prefetch_page;
+       context->sync_page = paging64_sync_page;
+       context->invlpg = paging64_invlpg;
        context->free = paging_free;
        context->root_level = level;
        context->shadow_root_level = level;
@@ -1243,6 +2062,8 @@ static int paging32_init_context(struct kvm_vcpu *vcpu)
        context->gva_to_gpa = paging32_gva_to_gpa;
        context->free = paging_free;
        context->prefetch_page = paging32_prefetch_page;
+       context->sync_page = paging32_sync_page;
+       context->invlpg = paging32_invlpg;
        context->root_level = PT32_ROOT_LEVEL;
        context->shadow_root_level = PT32E_ROOT_LEVEL;
        context->root_hpa = INVALID_PAGE;
@@ -1254,7 +2075,37 @@ static int paging32E_init_context(struct kvm_vcpu *vcpu)
        return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
 }
 
-static int init_kvm_mmu(struct kvm_vcpu *vcpu)
+static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
+{
+       struct kvm_mmu *context = &vcpu->arch.mmu;
+
+       context->new_cr3 = nonpaging_new_cr3;
+       context->page_fault = tdp_page_fault;
+       context->free = nonpaging_free;
+       context->prefetch_page = nonpaging_prefetch_page;
+       context->sync_page = nonpaging_sync_page;
+       context->invlpg = nonpaging_invlpg;
+       context->shadow_root_level = kvm_x86_ops->get_tdp_level();
+       context->root_hpa = INVALID_PAGE;
+
+       if (!is_paging(vcpu)) {
+               context->gva_to_gpa = nonpaging_gva_to_gpa;
+               context->root_level = 0;
+       } else if (is_long_mode(vcpu)) {
+               context->gva_to_gpa = paging64_gva_to_gpa;
+               context->root_level = PT64_ROOT_LEVEL;
+       } else if (is_pae(vcpu)) {
+               context->gva_to_gpa = paging64_gva_to_gpa;
+               context->root_level = PT32E_ROOT_LEVEL;
+       } else {
+               context->gva_to_gpa = paging32_gva_to_gpa;
+               context->root_level = PT32_ROOT_LEVEL;
+       }
+
+       return 0;
+}
+
+static int init_kvm_softmmu(struct kvm_vcpu *vcpu)
 {
        ASSERT(vcpu);
        ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
@@ -1269,6 +2120,16 @@ static int init_kvm_mmu(struct kvm_vcpu *vcpu)
                return paging32_init_context(vcpu);
 }
 
+static int init_kvm_mmu(struct kvm_vcpu *vcpu)
+{
+       vcpu->arch.update_pte.pfn = bad_pfn;
+
+       if (tdp_enabled)
+               return init_kvm_tdp_mmu(vcpu);
+       else
+               return init_kvm_softmmu(vcpu);
+}
+
 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
 {
        ASSERT(vcpu);
@@ -1295,6 +2156,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
        spin_lock(&vcpu->kvm->mmu_lock);
        kvm_mmu_free_some_pages(vcpu);
        mmu_alloc_roots(vcpu);
+       mmu_sync_roots(vcpu);
        spin_unlock(&vcpu->kvm->mmu_lock);
        kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
        kvm_mmu_flush_tlb(vcpu);
@@ -1317,7 +2179,8 @@ static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
 
        pte = *spte;
        if (is_shadow_present_pte(pte)) {
-               if (sp->role.level == PT_PAGE_TABLE_LEVEL)
+               if (sp->role.level == PT_PAGE_TABLE_LEVEL ||
+                   is_large_pte(pte))
                        rmap_remove(vcpu->kvm, spte);
                else {
                        child = page_header(pte & PT64_BASE_ADDR_MASK);
@@ -1325,6 +2188,8 @@ static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
                }
        }
        set_shadow_pte(spte, shadow_trap_nonpresent_pte);
+       if (is_large_pte(pte))
+               --vcpu->kvm->stat.lpages;
 }
 
 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
@@ -1333,9 +2198,12 @@ static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
                                  const void *new)
 {
        if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
-               ++vcpu->kvm->stat.mmu_pde_zapped;
-               return;
-       }
+               if (!vcpu->arch.update_pte.largepage ||
+                   sp->role.glevels == PT32_ROOT_LEVEL) {
+                       ++vcpu->kvm->stat.mmu_pde_zapped;
+                       return;
+               }
+        }
 
        ++vcpu->kvm->stat.mmu_pte_updated;
        if (sp->role.glevels == PT32_ROOT_LEVEL)
@@ -1369,7 +2237,7 @@ static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
 {
        u64 *spte = vcpu->arch.last_pte_updated;
 
-       return !!(spte && (*spte & PT_ACCESSED_MASK));
+       return !!(spte && (*spte & shadow_accessed_mask));
 }
 
 static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
@@ -1378,7 +2246,9 @@ static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
        gfn_t gfn;
        int r;
        u64 gpte = 0;
-       struct page *page;
+       pfn_t pfn;
+
+       vcpu->arch.update_pte.largepage = 0;
 
        if (bytes != 4 && bytes != 8)
                return;
@@ -1407,16 +2277,32 @@ static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
                return;
        gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
 
-       down_read(&vcpu->kvm->slots_lock);
-       page = gfn_to_page(vcpu->kvm, gfn);
-       up_read(&vcpu->kvm->slots_lock);
+       if (is_large_pte(gpte) && is_largepage_backed(vcpu, gfn)) {
+               gfn &= ~(KVM_PAGES_PER_HPAGE-1);
+               vcpu->arch.update_pte.largepage = 1;
+       }
+       vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq;
+       smp_rmb();
+       pfn = gfn_to_pfn(vcpu->kvm, gfn);
 
-       if (is_error_page(page)) {
-               kvm_release_page_clean(page);
+       if (is_error_pfn(pfn)) {
+               kvm_release_pfn_clean(pfn);
                return;
        }
        vcpu->arch.update_pte.gfn = gfn;
-       vcpu->arch.update_pte.page = page;
+       vcpu->arch.update_pte.pfn = pfn;
+}
+
+static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+       u64 *spte = vcpu->arch.last_pte_updated;
+
+       if (spte
+           && vcpu->arch.last_pte_gfn == gfn
+           && shadow_accessed_mask
+           && !(*spte & shadow_accessed_mask)
+           && is_shadow_present_pte(*spte))
+               set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
 }
 
 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
@@ -1439,9 +2325,10 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
        int npte;
        int r;
 
-       pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes);
+       pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);
        mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes);
        spin_lock(&vcpu->kvm->mmu_lock);
+       kvm_mmu_access_page(vcpu, gfn);
        kvm_mmu_free_some_pages(vcpu);
        ++vcpu->kvm->stat.mmu_pte_write;
        kvm_mmu_audit(vcpu, "pre pte write");
@@ -1458,7 +2345,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
        index = kvm_page_table_hashfn(gfn);
        bucket = &vcpu->kvm->arch.mmu_page_hash[index];
        hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
-               if (sp->gfn != gfn || sp->role.metaphysical)
+               if (sp->gfn != gfn || sp->role.metaphysical || sp->role.invalid)
                        continue;
                pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
                misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
@@ -1476,7 +2363,8 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
                         */
                        pgprintk("misaligned: gpa %llx bytes %d role %x\n",
                                 gpa, bytes, sp->role.word);
-                       kvm_mmu_zap_page(vcpu->kvm, sp);
+                       if (kvm_mmu_zap_page(vcpu->kvm, sp))
+                               n = bucket->first;
                        ++vcpu->kvm->stat.mmu_flooded;
                        continue;
                }
@@ -1521,9 +2409,9 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
        }
        kvm_mmu_audit(vcpu, "post pte write");
        spin_unlock(&vcpu->kvm->mmu_lock);
-       if (vcpu->arch.update_pte.page) {
-               kvm_release_page_clean(vcpu->arch.update_pte.page);
-               vcpu->arch.update_pte.page = NULL;
+       if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
+               kvm_release_pfn_clean(vcpu->arch.update_pte.pfn);
+               vcpu->arch.update_pte.pfn = bad_pfn;
        }
 }
 
@@ -1532,15 +2420,14 @@ int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
        gpa_t gpa;
        int r;
 
-       down_read(&vcpu->kvm->slots_lock);
        gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
-       up_read(&vcpu->kvm->slots_lock);
 
        spin_lock(&vcpu->kvm->mmu_lock);
        r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
        spin_unlock(&vcpu->kvm->mmu_lock);
        return r;
 }
+EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt);
 
 void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
 {
@@ -1591,12 +2478,28 @@ out:
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
 
+void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
+{
+       spin_lock(&vcpu->kvm->mmu_lock);
+       vcpu->arch.mmu.invlpg(vcpu, gva);
+       spin_unlock(&vcpu->kvm->mmu_lock);
+       kvm_mmu_flush_tlb(vcpu);
+       ++vcpu->stat.invlpg;
+}
+EXPORT_SYMBOL_GPL(kvm_mmu_invlpg);
+
 void kvm_enable_tdp(void)
 {
        tdp_enabled = true;
 }
 EXPORT_SYMBOL_GPL(kvm_enable_tdp);
 
+void kvm_disable_tdp(void)
+{
+       tdp_enabled = false;
+}
+EXPORT_SYMBOL_GPL(kvm_disable_tdp);
+
 static void free_mmu_pages(struct kvm_vcpu *vcpu)
 {
        struct kvm_mmu_page *sp;
@@ -1605,6 +2508,7 @@ static void free_mmu_pages(struct kvm_vcpu *vcpu)
                sp = container_of(vcpu->kvm->arch.active_mmu_pages.next,
                                  struct kvm_mmu_page, link);
                kvm_mmu_zap_page(vcpu->kvm, sp);
+               cond_resched();
        }
        free_page((unsigned long)vcpu->arch.mmu.pae_root);
 }
@@ -1670,11 +2574,12 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
 {
        struct kvm_mmu_page *sp;
 
+       spin_lock(&kvm->mmu_lock);
        list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
                int i;
                u64 *pt;
 
-               if (!test_bit(slot, &sp->slot_bitmap))
+               if (!test_bit(slot, sp->slot_bitmap))
                        continue;
 
                pt = sp->spt;
@@ -1683,6 +2588,8 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
                        if (pt[i] & PT_WRITABLE_MASK)
                                pt[i] &= ~PT_WRITABLE_MASK;
        }
+       kvm_flush_remote_tlbs(kvm);
+       spin_unlock(&kvm->mmu_lock);
 }
 
 void kvm_mmu_zap_all(struct kvm *kvm)
@@ -1691,13 +2598,64 @@ void kvm_mmu_zap_all(struct kvm *kvm)
 
        spin_lock(&kvm->mmu_lock);
        list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
-               kvm_mmu_zap_page(kvm, sp);
+               if (kvm_mmu_zap_page(kvm, sp))
+                       node = container_of(kvm->arch.active_mmu_pages.next,
+                                           struct kvm_mmu_page, link);
        spin_unlock(&kvm->mmu_lock);
 
        kvm_flush_remote_tlbs(kvm);
 }
 
-void kvm_mmu_module_exit(void)
+static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm *kvm)
+{
+       struct kvm_mmu_page *page;
+
+       page = container_of(kvm->arch.active_mmu_pages.prev,
+                           struct kvm_mmu_page, link);
+       kvm_mmu_zap_page(kvm, page);
+}
+
+static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask)
+{
+       struct kvm *kvm;
+       struct kvm *kvm_freed = NULL;
+       int cache_count = 0;
+
+       spin_lock(&kvm_lock);
+
+       list_for_each_entry(kvm, &vm_list, vm_list) {
+               int npages;
+
+               if (!down_read_trylock(&kvm->slots_lock))
+                       continue;
+               spin_lock(&kvm->mmu_lock);
+               npages = kvm->arch.n_alloc_mmu_pages -
+                        kvm->arch.n_free_mmu_pages;
+               cache_count += npages;
+               if (!kvm_freed && nr_to_scan > 0 && npages > 0) {
+                       kvm_mmu_remove_one_alloc_mmu_page(kvm);
+                       cache_count--;
+                       kvm_freed = kvm;
+               }
+               nr_to_scan--;
+
+               spin_unlock(&kvm->mmu_lock);
+               up_read(&kvm->slots_lock);
+       }
+       if (kvm_freed)
+               list_move_tail(&kvm_freed->vm_list, &vm_list);
+
+       spin_unlock(&kvm_lock);
+
+       return cache_count;
+}
+
+static struct shrinker mmu_shrinker = {
+       .shrink = mmu_shrink,
+       .seeks = DEFAULT_SEEKS * 10,
+};
+
+static void mmu_destroy_caches(void)
 {
        if (pte_chain_cache)
                kmem_cache_destroy(pte_chain_cache);
@@ -1707,6 +2665,12 @@ void kvm_mmu_module_exit(void)
                kmem_cache_destroy(mmu_page_header_cache);
 }
 
+void kvm_mmu_module_exit(void)
+{
+       mmu_destroy_caches();
+       unregister_shrinker(&mmu_shrinker);
+}
+
 int kvm_mmu_module_init(void)
 {
        pte_chain_cache = kmem_cache_create("kvm_pte_chain",
@@ -1726,10 +2690,12 @@ int kvm_mmu_module_init(void)
        if (!mmu_page_header_cache)
                goto nomem;
 
+       register_shrinker(&mmu_shrinker);
+
        return 0;
 
 nomem:
-       kvm_mmu_module_exit();
+       mmu_destroy_caches();
        return -ENOMEM;
 }
 
@@ -1752,6 +2718,128 @@ unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
        return nr_mmu_pages;
 }
 
+static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer *buffer,
+                               unsigned len)
+{
+       if (len > buffer->len)
+               return NULL;
+       return buffer->ptr;
+}
+
+static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer *buffer,
+                               unsigned len)
+{
+       void *ret;
+
+       ret = pv_mmu_peek_buffer(buffer, len);
+       if (!ret)
+               return ret;
+       buffer->ptr += len;
+       buffer->len -= len;
+       buffer->processed += len;
+       return ret;
+}
+
+static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu,
+                            gpa_t addr, gpa_t value)
+{
+       int bytes = 8;
+       int r;
+
+       if (!is_long_mode(vcpu) && !is_pae(vcpu))
+               bytes = 4;
+
+       r = mmu_topup_memory_caches(vcpu);
+       if (r)
+               return r;
+
+       if (!emulator_write_phys(vcpu, addr, &value, bytes))
+               return -EFAULT;
+
+       return 1;
+}
+
+static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu)
+{
+       kvm_x86_ops->tlb_flush(vcpu);
+       set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests);
+       return 1;
+}
+
+static int kvm_pv_mmu_release_pt(struct kvm_vcpu *vcpu, gpa_t addr)
+{
+       spin_lock(&vcpu->kvm->mmu_lock);
+       mmu_unshadow(vcpu->kvm, addr >> PAGE_SHIFT);
+       spin_unlock(&vcpu->kvm->mmu_lock);
+       return 1;
+}
+
+static int kvm_pv_mmu_op_one(struct kvm_vcpu *vcpu,
+                            struct kvm_pv_mmu_op_buffer *buffer)
+{
+       struct kvm_mmu_op_header *header;
+
+       header = pv_mmu_peek_buffer(buffer, sizeof *header);
+       if (!header)
+               return 0;
+       switch (header->op) {
+       case KVM_MMU_OP_WRITE_PTE: {
+               struct kvm_mmu_op_write_pte *wpte;
+
+               wpte = pv_mmu_read_buffer(buffer, sizeof *wpte);
+               if (!wpte)
+                       return 0;
+               return kvm_pv_mmu_write(vcpu, wpte->pte_phys,
+                                       wpte->pte_val);
+       }
+       case KVM_MMU_OP_FLUSH_TLB: {
+               struct kvm_mmu_op_flush_tlb *ftlb;
+
+               ftlb = pv_mmu_read_buffer(buffer, sizeof *ftlb);
+               if (!ftlb)
+                       return 0;
+               return kvm_pv_mmu_flush_tlb(vcpu);
+       }
+       case KVM_MMU_OP_RELEASE_PT: {
+               struct kvm_mmu_op_release_pt *rpt;
+
+               rpt = pv_mmu_read_buffer(buffer, sizeof *rpt);
+               if (!rpt)
+                       return 0;
+               return kvm_pv_mmu_release_pt(vcpu, rpt->pt_phys);
+       }
+       default: return 0;
+       }
+}
+
+int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
+                 gpa_t addr, unsigned long *ret)
+{
+       int r;
+       struct kvm_pv_mmu_op_buffer *buffer = &vcpu->arch.mmu_op_buffer;
+
+       buffer->ptr = buffer->buf;
+       buffer->len = min_t(unsigned long, bytes, sizeof buffer->buf);
+       buffer->processed = 0;
+
+       r = kvm_read_guest(vcpu->kvm, addr, buffer->buf, buffer->len);
+       if (r)
+               goto out;
+
+       while (buffer->len) {
+               r = kvm_pv_mmu_op_one(vcpu, buffer);
+               if (r < 0)
+                       goto out;
+               if (r == 0)
+                       break;
+       }
+
+       r = 1;
+out:
+       *ret = buffer->processed;
+       return r;
+}
+
 #ifdef AUDIT
 
 static const char *audit_msg;
@@ -1788,8 +2876,7 @@ static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
                        audit_mappings_page(vcpu, ent, va, level - 1);
                } else {
                        gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
-                       struct page *page = gpa_to_page(vcpu, gpa);
-                       hpa_t hpa = page_to_phys(page);
+                       hpa_t hpa = (hpa_t)gpa_to_pfn(vcpu, gpa) << PAGE_SHIFT;
 
                        if (is_shadow_present_pte(ent)
                            && (ent & PT64_BASE_ADDR_MASK) != hpa)
@@ -1802,7 +2889,7 @@ static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
                                 && !is_error_hpa(hpa))
                                printk(KERN_ERR "audit: (%s) notrap shadow,"
                                       " valid guest gva %lx\n", audit_msg, va);
-                       kvm_release_page_clean(page);
+                       kvm_release_pfn_clean(pfn);
 
                }
        }
@@ -1887,7 +2974,7 @@ static void audit_rmap(struct kvm_vcpu *vcpu)
 
        if (n_rmap != n_actual)
                printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
-                      __FUNCTION__, audit_msg, n_rmap, n_actual);
+                      __func__, audit_msg, n_rmap, n_actual);
 }
 
 static void audit_write_protection(struct kvm_vcpu *vcpu)
@@ -1901,13 +2988,13 @@ static void audit_write_protection(struct kvm_vcpu *vcpu)
                if (sp->role.metaphysical)
                        continue;
 
-               slot = gfn_to_memslot(vcpu->kvm, sp->gfn);
                gfn = unalias_gfn(vcpu->kvm, sp->gfn);
+               slot = gfn_to_memslot_unaliased(vcpu->kvm, sp->gfn);
                rmapp = &slot->rmap[gfn - slot->base_gfn];
                if (*rmapp)
                        printk(KERN_ERR "%s: (%s) shadow page has writable"
                               " mappings: gfn %lx role %x\n",
-                              __FUNCTION__, audit_msg, sp->gfn,
+                              __func__, audit_msg, sp->gfn,
                               sp->role.word);
        }
 }