KVM: Fix unused but set warnings
[linux-2.6.git] / arch / x86 / kvm / paging_tmpl.h
index ebb26a0..9308be2 100644 (file)
@@ -7,6 +7,7 @@
  * MMU support
  *
  * Copyright (C) 2006 Qumranet, Inc.
+ * Copyright 2010 Red Hat, Inc. and/or its affilates.
  *
  * Authors:
  *   Yaniv Kamay  <yaniv@qumranet.com>
@@ -27,7 +28,8 @@
        #define guest_walker guest_walker64
        #define FNAME(name) paging##64_##name
        #define PT_BASE_ADDR_MASK PT64_BASE_ADDR_MASK
-       #define PT_DIR_BASE_ADDR_MASK PT64_DIR_BASE_ADDR_MASK
+       #define PT_LVL_ADDR_MASK(lvl) PT64_LVL_ADDR_MASK(lvl)
+       #define PT_LVL_OFFSET_MASK(lvl) PT64_LVL_OFFSET_MASK(lvl)
        #define PT_INDEX(addr, level) PT64_INDEX(addr, level)
        #define PT_LEVEL_MASK(level) PT64_LEVEL_MASK(level)
        #define PT_LEVEL_BITS PT64_LEVEL_BITS
@@ -43,7 +45,8 @@
        #define guest_walker guest_walker32
        #define FNAME(name) paging##32_##name
        #define PT_BASE_ADDR_MASK PT32_BASE_ADDR_MASK
-       #define PT_DIR_BASE_ADDR_MASK PT32_DIR_BASE_ADDR_MASK
+       #define PT_LVL_ADDR_MASK(lvl) PT32_LVL_ADDR_MASK(lvl)
+       #define PT_LVL_OFFSET_MASK(lvl) PT32_LVL_OFFSET_MASK(lvl)
        #define PT_INDEX(addr, level) PT32_INDEX(addr, level)
        #define PT_LEVEL_MASK(level) PT32_LEVEL_MASK(level)
        #define PT_LEVEL_BITS PT32_LEVEL_BITS
@@ -53,8 +56,8 @@
        #error Invalid PTTYPE value
 #endif
 
-#define gpte_to_gfn FNAME(gpte_to_gfn)
-#define gpte_to_gfn_pde FNAME(gpte_to_gfn_pde)
+#define gpte_to_gfn_lvl FNAME(gpte_to_gfn_lvl)
+#define gpte_to_gfn(pte) gpte_to_gfn_lvl((pte), PT_PAGE_TABLE_LEVEL)
 
 /*
  * The guest_walker structure emulates the behavior of the hardware page
@@ -71,14 +74,9 @@ struct guest_walker {
        u32 error_code;
 };
 
-static gfn_t gpte_to_gfn(pt_element_t gpte)
+static gfn_t gpte_to_gfn_lvl(pt_element_t gpte, int lvl)
 {
-       return (gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT;
-}
-
-static gfn_t gpte_to_gfn_pde(pt_element_t gpte)
-{
-       return (gpte & PT_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
+       return (gpte & PT_LVL_ADDR_MASK(lvl)) >> PAGE_SHIFT;
 }
 
 static bool FNAME(cmpxchg_gpte)(struct kvm *kvm,
@@ -89,14 +87,10 @@ static bool FNAME(cmpxchg_gpte)(struct kvm *kvm,
        pt_element_t *table;
        struct page *page;
 
-       down_read(&current->mm->mmap_sem);
        page = gfn_to_page(kvm, table_gfn);
-       up_read(&current->mm->mmap_sem);
 
        table = kmap_atomic(page, KM_USER0);
-
        ret = CMPXCHG(&table[index], orig_pte, new_pte);
-
        kunmap_atomic(table, KM_USER0);
 
        kvm_release_page_dirty(page);
@@ -127,15 +121,18 @@ static int FNAME(walk_addr)(struct guest_walker *walker,
        gfn_t table_gfn;
        unsigned index, pt_access, pte_access;
        gpa_t pte_gpa;
+       int rsvd_fault = 0;
 
-       pgprintk("%s: addr %lx\n", __func__, addr);
+       trace_kvm_mmu_pagetable_walk(addr, write_fault, user_fault,
+                                    fetch_fault);
 walk:
        walker->level = vcpu->arch.mmu.root_level;
        pte = vcpu->arch.cr3;
 #if PTTYPE == 64
        if (!is_long_mode(vcpu)) {
-               pte = vcpu->arch.pdptrs[(addr >> 30) & 3];
-               if (!is_present_pte(pte))
+               pte = kvm_pdptr_read(vcpu, (addr >> 30) & 3);
+               trace_kvm_mmu_paging_element(pte, walker->level);
+               if (!is_present_gpte(pte))
                        goto not_present;
                --walker->level;
        }
@@ -153,15 +150,20 @@ walk:
                pte_gpa += index * sizeof(pt_element_t);
                walker->table_gfn[walker->level - 1] = table_gfn;
                walker->pte_gpa[walker->level - 1] = pte_gpa;
-               pgprintk("%s: table_gfn[%d] %lx\n", __func__,
-                        walker->level - 1, table_gfn);
 
-               kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte));
+               if (kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte)))
+                       goto not_present;
+
+               trace_kvm_mmu_paging_element(pte, walker->level);
 
-               if (!is_present_pte(pte))
+               if (!is_present_gpte(pte))
                        goto not_present;
 
-               if (write_fault && !is_writeble_pte(pte))
+               rsvd_fault = is_rsvd_bits_set(vcpu, pte, walker->level);
+               if (rsvd_fault)
+                       goto access_error;
+
+               if (write_fault && !is_writable_pte(pte))
                        if (user_fault || is_write_protection(vcpu))
                                goto access_error;
 
@@ -169,15 +171,17 @@ walk:
                        goto access_error;
 
 #if PTTYPE == 64
-               if (fetch_fault && is_nx(vcpu) && (pte & PT64_NX_MASK))
+               if (fetch_fault && (pte & PT64_NX_MASK))
                        goto access_error;
 #endif
 
                if (!(pte & PT_ACCESSED_MASK)) {
-                       mark_page_dirty(vcpu->kvm, table_gfn);
+                       trace_kvm_mmu_set_accessed_bit(table_gfn, index,
+                                                      sizeof(pte));
                        if (FNAME(cmpxchg_gpte)(vcpu->kvm, table_gfn,
                            index, pte, pte|PT_ACCESSED_MASK))
                                goto walk;
+                       mark_page_dirty(vcpu->kvm, table_gfn);
                        pte |= PT_ACCESSED_MASK;
                }
 
@@ -185,18 +189,24 @@ walk:
 
                walker->ptes[walker->level - 1] = pte;
 
-               if (walker->level == PT_PAGE_TABLE_LEVEL) {
-                       walker->gfn = gpte_to_gfn(pte);
-                       break;
-               }
-
-               if (walker->level == PT_DIRECTORY_LEVEL
-                   && (pte & PT_PAGE_SIZE_MASK)
-                   && (PTTYPE == 64 || is_pse(vcpu))) {
-                       walker->gfn = gpte_to_gfn_pde(pte);
-                       walker->gfn += PT_INDEX(addr, PT_PAGE_TABLE_LEVEL);
-                       if (PTTYPE == 32 && is_cpuid_PSE36())
+               if ((walker->level == PT_PAGE_TABLE_LEVEL) ||
+                   ((walker->level == PT_DIRECTORY_LEVEL) &&
+                               is_large_pte(pte) &&
+                               (PTTYPE == 64 || is_pse(vcpu))) ||
+                   ((walker->level == PT_PDPE_LEVEL) &&
+                               is_large_pte(pte) &&
+                               is_long_mode(vcpu))) {
+                       int lvl = walker->level;
+
+                       walker->gfn = gpte_to_gfn_lvl(pte, lvl);
+                       walker->gfn += (addr & PT_LVL_OFFSET_MASK(lvl))
+                                       >> PAGE_SHIFT;
+
+                       if (PTTYPE == 32 &&
+                           walker->level == PT_DIRECTORY_LEVEL &&
+                           is_cpuid_PSE36())
                                walker->gfn += pse36_gfn_delta(pte);
+
                        break;
                }
 
@@ -204,23 +214,23 @@ walk:
                --walker->level;
        }
 
-       if (write_fault && !is_dirty_pte(pte)) {
+       if (write_fault && !is_dirty_gpte(pte)) {
                bool ret;
 
-               mark_page_dirty(vcpu->kvm, table_gfn);
+               trace_kvm_mmu_set_dirty_bit(table_gfn, index, sizeof(pte));
                ret = FNAME(cmpxchg_gpte)(vcpu->kvm, table_gfn, index, pte,
                            pte|PT_DIRTY_MASK);
                if (ret)
                        goto walk;
+               mark_page_dirty(vcpu->kvm, table_gfn);
                pte |= PT_DIRTY_MASK;
-               kvm_mmu_pte_write(vcpu, pte_gpa, (u8 *)&pte, sizeof(pte));
                walker->ptes[walker->level - 1] = pte;
        }
 
        walker->pt_access = pt_access;
        walker->pte_access = pte_access;
        pgprintk("%s: pte %llx pte_access %x pt_access %x\n",
-                __func__, (u64)pte, pt_access, pte_access);
+                __func__, (u64)pte, pte_access, pt_access);
        return 1;
 
 not_present:
@@ -237,6 +247,9 @@ err:
                walker->error_code |= PFERR_USER_MASK;
        if (fetch_fault)
                walker->error_code |= PFERR_FETCH_MASK;
+       if (rsvd_fault)
+               walker->error_code |= PFERR_RSVD_MASK;
+       trace_kvm_mmu_walker_error(walker->error_code);
        return 0;
 }
 
@@ -246,12 +259,17 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
        pt_element_t gpte;
        unsigned pte_access;
        pfn_t pfn;
-       int largepage = vcpu->arch.update_pte.largepage;
+       u64 new_spte;
 
        gpte = *(const pt_element_t *)pte;
        if (~gpte & (PT_PRESENT_MASK | PT_ACCESSED_MASK)) {
-               if (!is_present_pte(gpte))
-                       set_shadow_pte(spte, shadow_notrap_nonpresent_pte);
+               if (!is_present_gpte(gpte)) {
+                       if (page->unsync)
+                               new_spte = shadow_trap_nonpresent_pte;
+                       else
+                               new_spte = shadow_notrap_nonpresent_pte;
+                       __set_spte(spte, new_spte);
+               }
                return;
        }
        pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte);
@@ -264,94 +282,96 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
        if (mmu_notifier_retry(vcpu, vcpu->arch.update_pte.mmu_seq))
                return;
        kvm_get_pfn(pfn);
+       /*
+        * we call mmu_set_spte() with reset_host_protection = true beacuse that
+        * vcpu->arch.update_pte.pfn was fetched from get_user_pages(write = 1).
+        */
        mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0,
-                    gpte & PT_DIRTY_MASK, NULL, largepage, gpte_to_gfn(gpte),
-                    pfn, true);
+                    gpte & PT_DIRTY_MASK, NULL, PT_PAGE_TABLE_LEVEL,
+                    gpte_to_gfn(gpte), pfn, true, true);
 }
 
 /*
  * Fetch a shadow pte for a specific level in the paging hierarchy.
  */
 static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
-                        struct guest_walker *walker,
-                        int user_fault, int write_fault, int largepage,
+                        struct guest_walker *gw,
+                        int user_fault, int write_fault, int hlevel,
                         int *ptwrite, pfn_t pfn)
 {
-       hpa_t shadow_addr;
+       unsigned access = gw->pt_access;
+       struct kvm_mmu_page *shadow_page;
+       u64 spte, *sptep = NULL;
+       int direct;
+       gfn_t table_gfn;
+       int r;
        int level;
-       u64 *shadow_ent;
-       unsigned access = walker->pt_access;
+       pt_element_t curr_pte;
+       struct kvm_shadow_walk_iterator iterator;
 
-       if (!is_present_pte(walker->ptes[walker->level - 1]))
+       if (!is_present_gpte(gw->ptes[gw->level - 1]))
                return NULL;
 
-       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;
-       }
-
-       for (; ; level--) {
-               u32 index = SHADOW_PT_INDEX(addr, level);
-               struct kvm_mmu_page *shadow_page;
-               u64 shadow_pte;
-               int metaphysical;
-               gfn_t table_gfn;
-
-               shadow_ent = ((u64 *)__va(shadow_addr)) + index;
-               if (level == PT_PAGE_TABLE_LEVEL)
-                       break;
-
-               if (largepage && level == PT_DIRECTORY_LEVEL)
+       for_each_shadow_entry(vcpu, addr, iterator) {
+               level = iterator.level;
+               sptep = iterator.sptep;
+               if (iterator.level == hlevel) {
+                       mmu_set_spte(vcpu, sptep, access,
+                                    gw->pte_access & access,
+                                    user_fault, write_fault,
+                                    gw->ptes[gw->level-1] & PT_DIRTY_MASK,
+                                    ptwrite, level,
+                                    gw->gfn, pfn, false, true);
                        break;
+               }
 
-               if (is_shadow_present_pte(*shadow_ent)
-                   && !is_large_pte(*shadow_ent)) {
-                       shadow_addr = *shadow_ent & PT64_BASE_ADDR_MASK;
+               if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep))
                        continue;
-               }
 
-               if (is_large_pte(*shadow_ent))
-                       rmap_remove(vcpu->kvm, shadow_ent);
+               if (is_large_pte(*sptep)) {
+                       rmap_remove(vcpu->kvm, sptep);
+                       __set_spte(sptep, shadow_trap_nonpresent_pte);
+                       kvm_flush_remote_tlbs(vcpu->kvm);
+               }
 
-               if (level - 1 == PT_PAGE_TABLE_LEVEL
-                   && walker->level == PT_DIRECTORY_LEVEL) {
-                       metaphysical = 1;
-                       if (!is_dirty_pte(walker->ptes[level - 1]))
+               if (level <= gw->level) {
+                       int delta = level - gw->level + 1;
+                       direct = 1;
+                       if (!is_dirty_gpte(gw->ptes[level - delta]))
                                access &= ~ACC_WRITE_MASK;
-                       table_gfn = gpte_to_gfn(walker->ptes[level - 1]);
+                       /*
+                        * It is a large guest pages backed by small host pages,
+                        * So we set @direct(@shadow_page->role.direct)=1, and
+                        * set @table_gfn(@shadow_page->gfn)=the base page frame
+                        * for linear translations.
+                        */
+                       table_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1);
+                       access &= gw->pte_access;
                } else {
-                       metaphysical = 0;
-                       table_gfn = walker->table_gfn[level - 2];
+                       direct = 0;
+                       table_gfn = gw->table_gfn[level - 2];
                }
                shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1,
-                                              metaphysical, access,
-                                              shadow_ent);
-               if (!metaphysical) {
-                       int r;
-                       pt_element_t curr_pte;
+                                              direct, access, sptep);
+               if (!direct) {
                        r = kvm_read_guest_atomic(vcpu->kvm,
-                                                 walker->pte_gpa[level - 2],
+                                                 gw->pte_gpa[level - 2],
                                                  &curr_pte, sizeof(curr_pte));
-                       if (r || curr_pte != walker->ptes[level - 2]) {
+                       if (r || curr_pte != gw->ptes[level - 2]) {
+                               kvm_mmu_put_page(shadow_page, sptep);
                                kvm_release_pfn_clean(pfn);
-                               return NULL;
+                               sptep = NULL;
+                               break;
                        }
                }
-               shadow_addr = __pa(shadow_page->spt);
-               shadow_pte = shadow_addr | PT_PRESENT_MASK | PT_ACCESSED_MASK
+
+               spte = __pa(shadow_page->spt)
+                       | PT_PRESENT_MASK | PT_ACCESSED_MASK
                        | PT_WRITABLE_MASK | PT_USER_MASK;
-               set_shadow_pte(shadow_ent, shadow_pte);
+               *sptep = spte;
        }
 
-       mmu_set_spte(vcpu, shadow_ent, access, walker->pte_access & access,
-                    user_fault, write_fault,
-                    walker->ptes[walker->level-1] & PT_DIRTY_MASK,
-                    ptwrite, largepage, walker->gfn, pfn, false);
-
-       return shadow_ent;
+       return sptep;
 }
 
 /*
@@ -375,11 +395,11 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
        int user_fault = error_code & PFERR_USER_MASK;
        int fetch_fault = error_code & PFERR_FETCH_MASK;
        struct guest_walker walker;
-       u64 *shadow_pte;
+       u64 *sptep;
        int write_pt = 0;
        int r;
        pfn_t pfn;
-       int largepage = 0;
+       int level = PT_PAGE_TABLE_LEVEL;
        unsigned long mmu_seq;
 
        pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code);
@@ -390,7 +410,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
                return r;
 
        /*
-        * Look up the shadow pte for the faulting address.
+        * Look up the guest pte for the faulting address.
         */
        r = FNAME(walk_addr)(&walker, vcpu, addr, write_fault, user_fault,
                             fetch_fault);
@@ -405,36 +425,28 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
                return 0;
        }
 
-       down_read(&current->mm->mmap_sem);
-       if (walker.level == PT_DIRECTORY_LEVEL) {
-               gfn_t large_gfn;
-               large_gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE-1);
-               if (is_largepage_backed(vcpu, large_gfn)) {
-                       walker.gfn = large_gfn;
-                       largepage = 1;
-               }
+       if (walker.level >= PT_DIRECTORY_LEVEL) {
+               level = min(walker.level, mapping_level(vcpu, walker.gfn));
+               walker.gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1);
        }
+
        mmu_seq = vcpu->kvm->mmu_notifier_seq;
-       /* implicit mb(), we'll read before PT lock is unlocked */
+       smp_rmb();
        pfn = gfn_to_pfn(vcpu->kvm, walker.gfn);
-       up_read(&current->mm->mmap_sem);
 
        /* mmio */
-       if (is_error_pfn(pfn)) {
-               pgprintk("gfn %lx is mmio\n", walker.gfn);
-               kvm_release_pfn_clean(pfn);
-               return 1;
-       }
+       if (is_error_pfn(pfn))
+               return kvm_handle_bad_page(vcpu->kvm, walker.gfn, pfn);
 
        spin_lock(&vcpu->kvm->mmu_lock);
        if (mmu_notifier_retry(vcpu, mmu_seq))
                goto out_unlock;
        kvm_mmu_free_some_pages(vcpu);
-       shadow_pte = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
-                                 largepage, &write_pt, pfn);
-
+       sptep = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
+                            level, &write_pt, pfn);
+       (void)sptep;
        pgprintk("%s: shadow pte %p %llx ptwrite %d\n", __func__,
-                shadow_pte, *shadow_pte, write_pt);
+                sptep, *sptep, write_pt);
 
        if (!write_pt)
                vcpu->arch.last_pt_write_count = 0; /* reset fork detector */
@@ -451,18 +463,81 @@ out_unlock:
        return 0;
 }
 
-static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)
+static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
+{
+       struct kvm_shadow_walk_iterator iterator;
+       struct kvm_mmu_page *sp;
+       gpa_t pte_gpa = -1;
+       int level;
+       u64 *sptep;
+       int need_flush = 0;
+
+       spin_lock(&vcpu->kvm->mmu_lock);
+
+       for_each_shadow_entry(vcpu, gva, iterator) {
+               level = iterator.level;
+               sptep = iterator.sptep;
+
+               sp = page_header(__pa(sptep));
+               if (is_last_spte(*sptep, level)) {
+                       int offset, shift;
+
+                       if (!sp->unsync)
+                               break;
+
+                       shift = PAGE_SHIFT -
+                                 (PT_LEVEL_BITS - PT64_LEVEL_BITS) * level;
+                       offset = sp->role.quadrant << shift;
+
+                       pte_gpa = (sp->gfn << PAGE_SHIFT) + offset;
+                       pte_gpa += (sptep - sp->spt) * sizeof(pt_element_t);
+
+                       if (is_shadow_present_pte(*sptep)) {
+                               rmap_remove(vcpu->kvm, sptep);
+                               if (is_large_pte(*sptep))
+                                       --vcpu->kvm->stat.lpages;
+                               need_flush = 1;
+                       }
+                       __set_spte(sptep, shadow_trap_nonpresent_pte);
+                       break;
+               }
+
+               if (!is_shadow_present_pte(*sptep) || !sp->unsync_children)
+                       break;
+       }
+
+       if (need_flush)
+               kvm_flush_remote_tlbs(vcpu->kvm);
+
+       atomic_inc(&vcpu->kvm->arch.invlpg_counter);
+
+       spin_unlock(&vcpu->kvm->mmu_lock);
+
+       if (pte_gpa == -1)
+               return;
+
+       if (mmu_topup_memory_caches(vcpu))
+               return;
+       kvm_mmu_pte_write(vcpu, pte_gpa, NULL, sizeof(pt_element_t), 0);
+}
+
+static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr, u32 access,
+                              u32 *error)
 {
        struct guest_walker walker;
        gpa_t gpa = UNMAPPED_GVA;
        int r;
 
-       r = FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0, 0);
+       r = FNAME(walk_addr)(&walker, vcpu, vaddr,
+                            !!(access & PFERR_WRITE_MASK),
+                            !!(access & PFERR_USER_MASK),
+                            !!(access & PFERR_FETCH_MASK));
 
        if (r) {
                gpa = gfn_to_gpa(walker.gfn);
                gpa |= vaddr & ~PAGE_MASK;
-       }
+       } else if (error)
+               *error = walker.error_code;
 
        return gpa;
 }
@@ -474,7 +549,7 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
        pt_element_t pt[256 / sizeof(pt_element_t)];
        gpa_t pte_gpa;
 
-       if (sp->role.metaphysical
+       if (sp->role.direct
            || (PTTYPE == 32 && sp->role.level > PT_PAGE_TABLE_LEVEL)) {
                nonpaging_prefetch_page(vcpu, sp);
                return;
@@ -490,22 +565,91 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
                r = kvm_read_guest_atomic(vcpu->kvm, pte_gpa, pt, sizeof pt);
                pte_gpa += ARRAY_SIZE(pt) * sizeof(pt_element_t);
                for (j = 0; j < ARRAY_SIZE(pt); ++j)
-                       if (r || is_present_pte(pt[j]))
+                       if (r || is_present_gpte(pt[j]))
                                sp->spt[i+j] = shadow_trap_nonpresent_pte;
                        else
                                sp->spt[i+j] = shadow_notrap_nonpresent_pte;
        }
 }
 
+/*
+ * Using the cached information from sp->gfns is safe because:
+ * - The spte has a reference to the struct page, so the pfn for a given gfn
+ *   can't change unless all sptes pointing to it are nuked first.
+ * - Alias changes zap the entire shadow cache.
+ */
+static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+{
+       int i, offset, nr_present;
+       bool reset_host_protection;
+       gpa_t first_pte_gpa;
+
+       offset = nr_present = 0;
+
+       /* direct kvm_mmu_page can not be unsync. */
+       BUG_ON(sp->role.direct);
+
+       if (PTTYPE == 32)
+               offset = sp->role.quadrant << PT64_LEVEL_BITS;
+
+       first_pte_gpa = gfn_to_gpa(sp->gfn) + offset * sizeof(pt_element_t);
+
+       for (i = 0; i < PT64_ENT_PER_PAGE; i++) {
+               unsigned pte_access;
+               pt_element_t gpte;
+               gpa_t pte_gpa;
+               gfn_t gfn;
+
+               if (!is_shadow_present_pte(sp->spt[i]))
+                       continue;
+
+               pte_gpa = first_pte_gpa + i * sizeof(pt_element_t);
+
+               if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte,
+                                         sizeof(pt_element_t)))
+                       return -EINVAL;
+
+               gfn = gpte_to_gfn(gpte);
+               if (unalias_gfn(vcpu->kvm, gfn) != sp->gfns[i] ||
+                     !is_present_gpte(gpte) || !(gpte & PT_ACCESSED_MASK)) {
+                       u64 nonpresent;
+
+                       rmap_remove(vcpu->kvm, &sp->spt[i]);
+                       if (is_present_gpte(gpte))
+                               nonpresent = shadow_trap_nonpresent_pte;
+                       else
+                               nonpresent = shadow_notrap_nonpresent_pte;
+                       __set_spte(&sp->spt[i], nonpresent);
+                       continue;
+               }
+
+               nr_present++;
+               pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
+               if (!(sp->spt[i] & SPTE_HOST_WRITEABLE)) {
+                       pte_access &= ~ACC_WRITE_MASK;
+                       reset_host_protection = 0;
+               } else {
+                       reset_host_protection = 1;
+               }
+               set_spte(vcpu, &sp->spt[i], pte_access, 0, 0,
+                        is_dirty_gpte(gpte), PT_PAGE_TABLE_LEVEL, gfn,
+                        spte_to_pfn(sp->spt[i]), true, false,
+                        reset_host_protection);
+       }
+
+       return !nr_present;
+}
+
 #undef pt_element_t
 #undef guest_walker
 #undef FNAME
 #undef PT_BASE_ADDR_MASK
 #undef PT_INDEX
 #undef PT_LEVEL_MASK
-#undef PT_DIR_BASE_ADDR_MASK
+#undef PT_LVL_ADDR_MASK
+#undef PT_LVL_OFFSET_MASK
 #undef PT_LEVEL_BITS
 #undef PT_MAX_FULL_LEVELS
 #undef gpte_to_gfn
-#undef gpte_to_gfn_pde
+#undef gpte_to_gfn_lvl
 #undef CMPXCHG