Merge branch 'hwmon-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6
[sfrench/cifs-2.6.git] / arch / x86 / kvm / mmu.c
index fa3486d64078a21a7d0a3fb33ee78da6a6296307..2d4477c7147372c28ed84f5a513ca553dc46979c 100644 (file)
@@ -621,7 +621,7 @@ static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte)
        return NULL;
 }
 
-static void rmap_write_protect(struct kvm *kvm, u64 gfn)
+static int rmap_write_protect(struct kvm *kvm, u64 gfn)
 {
        unsigned long *rmapp;
        u64 *spte;
@@ -667,8 +667,7 @@ static void rmap_write_protect(struct kvm *kvm, u64 gfn)
                spte = rmap_next(kvm, rmapp, spte);
        }
 
-       if (write_protected)
-               kvm_flush_remote_tlbs(kvm);
+       return write_protected;
 }
 
 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
@@ -794,9 +793,11 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
        sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
        set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
        list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
+       INIT_LIST_HEAD(&sp->oos_link);
        ASSERT(is_empty_shadow_page(sp->spt));
        bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
        sp->multimapped = 0;
+       sp->global = 1;
        sp->parent_pte = parent_pte;
        --vcpu->kvm->arch.n_free_mmu_pages;
        return sp;
@@ -908,8 +909,9 @@ static void kvm_mmu_update_unsync_bitmap(u64 *spte)
        struct kvm_mmu_page *sp = page_header(__pa(spte));
 
        index = spte - sp->spt;
-       __set_bit(index, sp->unsync_child_bitmap);
-       sp->unsync_children = 1;
+       if (!__test_and_set_bit(index, sp->unsync_child_bitmap))
+               sp->unsync_children++;
+       WARN_ON(!sp->unsync_children);
 }
 
 static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page *sp)
@@ -936,7 +938,6 @@ static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page *sp)
 
 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;
 }
@@ -967,38 +968,66 @@ static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
 {
 }
 
+#define KVM_PAGE_ARRAY_NR 16
+
+struct kvm_mmu_pages {
+       struct mmu_page_and_offset {
+               struct kvm_mmu_page *sp;
+               unsigned int idx;
+       } page[KVM_PAGE_ARRAY_NR];
+       unsigned int nr;
+};
+
 #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 mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp,
+                  int idx)
 {
-       int i, ret;
+       int i;
 
-       if (!sp->unsync_children)
-               return 0;
+       if (sp->unsync)
+               for (i=0; i < pvec->nr; i++)
+                       if (pvec->page[i].sp == sp)
+                               return 0;
+
+       pvec->page[pvec->nr].sp = sp;
+       pvec->page[pvec->nr].idx = idx;
+       pvec->nr++;
+       return (pvec->nr == KVM_PAGE_ARRAY_NR);
+}
+
+static int __mmu_unsync_walk(struct kvm_mmu_page *sp,
+                          struct kvm_mmu_pages *pvec)
+{
+       int i, ret, nr_unsync_leaf = 0;
 
        for_each_unsync_children(sp->unsync_child_bitmap, i) {
                u64 ent = sp->spt[i];
 
-               if (is_shadow_present_pte(ent)) {
+               if (is_shadow_present_pte(ent) && !is_large_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)
+                               if (mmu_pages_add(pvec, child, i))
+                                       return -ENOSPC;
+
+                               ret = __mmu_unsync_walk(child, pvec);
+                               if (!ret)
+                                       __clear_bit(i, sp->unsync_child_bitmap);
+                               else if (ret > 0)
+                                       nr_unsync_leaf += ret;
+                               else
                                        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;
+                               nr_unsync_leaf++;
+                               if (mmu_pages_add(pvec, child, i))
+                                       return -ENOSPC;
                        }
                }
        }
@@ -1006,7 +1035,17 @@ static int mmu_unsync_walk(struct kvm_mmu_page *sp,
        if (find_first_bit(sp->unsync_child_bitmap, 512) == 512)
                sp->unsync_children = 0;
 
-       return 0;
+       return nr_unsync_leaf;
+}
+
+static int mmu_unsync_walk(struct kvm_mmu_page *sp,
+                          struct kvm_mmu_pages *pvec)
+{
+       if (!sp->unsync_children)
+               return 0;
+
+       mmu_pages_add(pvec, sp, 0);
+       return __mmu_unsync_walk(sp, pvec);
 }
 
 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
@@ -1029,10 +1068,18 @@ static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
        return NULL;
 }
 
+static void kvm_unlink_unsync_global(struct kvm *kvm, struct kvm_mmu_page *sp)
+{
+       list_del(&sp->oos_link);
+       --kvm->stat.mmu_unsync_global;
+}
+
 static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
        WARN_ON(!sp->unsync);
        sp->unsync = 0;
+       if (sp->global)
+               kvm_unlink_unsync_global(kvm, sp);
        --kvm->stat.mmu_unsync;
 }
 
@@ -1045,7 +1092,8 @@ static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
                return 1;
        }
 
-       rmap_write_protect(vcpu->kvm, sp->gfn);
+       if (rmap_write_protect(vcpu->kvm, sp->gfn))
+               kvm_flush_remote_tlbs(vcpu->kvm);
        kvm_unlink_unsync_page(vcpu->kvm, sp);
        if (vcpu->arch.mmu.sync_page(vcpu, sp)) {
                kvm_mmu_zap_page(vcpu->kvm, sp);
@@ -1056,30 +1104,89 @@ static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
        return 0;
 }
 
-struct sync_walker {
-       struct kvm_vcpu *vcpu;
-       struct kvm_unsync_walk walker;
+struct mmu_page_path {
+       struct kvm_mmu_page *parent[PT64_ROOT_LEVEL-1];
+       unsigned int idx[PT64_ROOT_LEVEL-1];
 };
 
-static int mmu_sync_fn(struct kvm_mmu_page *sp, struct kvm_unsync_walk *walk)
+#define for_each_sp(pvec, sp, parents, i)                      \
+               for (i = mmu_pages_next(&pvec, &parents, -1),   \
+                       sp = pvec.page[i].sp;                   \
+                       i < pvec.nr && ({ sp = pvec.page[i].sp; 1;});   \
+                       i = mmu_pages_next(&pvec, &parents, i))
+
+int mmu_pages_next(struct kvm_mmu_pages *pvec, struct mmu_page_path *parents,
+                  int i)
 {
-       struct sync_walker *sync_walk = container_of(walk, struct sync_walker,
-                                                    walker);
-       struct kvm_vcpu *vcpu = sync_walk->vcpu;
+       int n;
+
+       for (n = i+1; n < pvec->nr; n++) {
+               struct kvm_mmu_page *sp = pvec->page[n].sp;
 
-       kvm_sync_page(vcpu, sp);
-       return (need_resched() || spin_needbreak(&vcpu->kvm->mmu_lock));
+               if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
+                       parents->idx[0] = pvec->page[n].idx;
+                       return n;
+               }
+
+               parents->parent[sp->role.level-2] = sp;
+               parents->idx[sp->role.level-1] = pvec->page[n].idx;
+       }
+
+       return n;
 }
 
-static void mmu_sync_children(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
+void mmu_pages_clear_parents(struct mmu_page_path *parents)
 {
-       struct sync_walker walker = {
-               .walker = { .entry = mmu_sync_fn, },
-               .vcpu = vcpu,
-       };
+       struct kvm_mmu_page *sp;
+       unsigned int level = 0;
+
+       do {
+               unsigned int idx = parents->idx[level];
+
+               sp = parents->parent[level];
+               if (!sp)
+                       return;
+
+               --sp->unsync_children;
+               WARN_ON((int)sp->unsync_children < 0);
+               __clear_bit(idx, sp->unsync_child_bitmap);
+               level++;
+       } while (level < PT64_ROOT_LEVEL-1 && !sp->unsync_children);
+}
 
-       while (mmu_unsync_walk(sp, &walker.walker))
+static void kvm_mmu_pages_init(struct kvm_mmu_page *parent,
+                              struct mmu_page_path *parents,
+                              struct kvm_mmu_pages *pvec)
+{
+       parents->parent[parent->role.level-1] = NULL;
+       pvec->nr = 0;
+}
+
+static void mmu_sync_children(struct kvm_vcpu *vcpu,
+                             struct kvm_mmu_page *parent)
+{
+       int i;
+       struct kvm_mmu_page *sp;
+       struct mmu_page_path parents;
+       struct kvm_mmu_pages pages;
+
+       kvm_mmu_pages_init(parent, &parents, &pages);
+       while (mmu_unsync_walk(parent, &pages)) {
+               int protected = 0;
+
+               for_each_sp(pages, sp, parents, i)
+                       protected |= rmap_write_protect(vcpu->kvm, sp->gfn);
+
+               if (protected)
+                       kvm_flush_remote_tlbs(vcpu->kvm);
+
+               for_each_sp(pages, sp, parents, i) {
+                       kvm_sync_page(vcpu, sp);
+                       mmu_pages_clear_parents(&parents);
+               }
                cond_resched_lock(&vcpu->kvm->mmu_lock);
+               kvm_mmu_pages_init(parent, &parents, &pages);
+       }
 }
 
 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
@@ -1137,7 +1244,8 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
        sp->role = role;
        hlist_add_head(&sp->hash_link, bucket);
        if (!metaphysical) {
-               rmap_write_protect(vcpu->kvm, gfn);
+               if (rmap_write_protect(vcpu->kvm, gfn))
+                       kvm_flush_remote_tlbs(vcpu->kvm);
                account_shadowed(vcpu->kvm, gfn);
        }
        if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte)
@@ -1161,6 +1269,8 @@ static int walk_shadow(struct kvm_shadow_walk *walker,
        if (level == PT32E_ROOT_LEVEL) {
                shadow_addr = vcpu->arch.mmu.pae_root[(addr >> 30) & 3];
                shadow_addr &= PT64_BASE_ADDR_MASK;
+               if (!shadow_addr)
+                       return 1;
                --level;
        }
 
@@ -1245,33 +1355,29 @@ static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
        }
 }
 
-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)
+static int mmu_zap_unsync_children(struct kvm *kvm,
+                                  struct kvm_mmu_page *parent)
 {
-       struct zap_walker walker = {
-               .walker = { .entry = mmu_zap_fn, },
-               .kvm = kvm,
-               .zapped = 0,
-       };
+       int i, zapped = 0;
+       struct mmu_page_path parents;
+       struct kvm_mmu_pages pages;
 
-       if (sp->role.level == PT_PAGE_TABLE_LEVEL)
+       if (parent->role.level == PT_PAGE_TABLE_LEVEL)
                return 0;
-       mmu_unsync_walk(sp, &walker.walker);
-       return walker.zapped;
+
+       kvm_mmu_pages_init(parent, &parents, &pages);
+       while (mmu_unsync_walk(parent, &pages)) {
+               struct kvm_mmu_page *sp;
+
+               for_each_sp(pages, sp, parents, i) {
+                       kvm_mmu_zap_page(kvm, sp);
+                       mmu_pages_clear_parents(&parents);
+               }
+               zapped += pages.nr;
+               kvm_mmu_pages_init(parent, &parents, &pages);
+       }
+
+       return zapped;
 }
 
 static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
@@ -1521,9 +1627,15 @@ static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
                if (s->role.word != sp->role.word)
                        return 1;
        }
-       kvm_mmu_mark_parents_unsync(vcpu, sp);
        ++vcpu->kvm->stat.mmu_unsync;
        sp->unsync = 1;
+
+       if (sp->global) {
+               list_add(&sp->oos_link, &vcpu->kvm->arch.oos_global_pages);
+               ++vcpu->kvm->stat.mmu_unsync_global;
+       } else
+               kvm_mmu_mark_parents_unsync(vcpu, sp);
+
        mmu_convert_notrap(sp);
        return 0;
 }
@@ -1549,12 +1661,23 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
 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,
+                   int global, gfn_t gfn, pfn_t pfn, bool speculative,
                    bool can_unsync)
 {
        u64 spte;
        int ret = 0;
        u64 mt_mask = shadow_mt_mask;
+       struct kvm_mmu_page *sp = page_header(__pa(shadow_pte));
+
+       if (!(vcpu->arch.cr4 & X86_CR4_PGE))
+               global = 0;
+       if (!global && sp->global) {
+               sp->global = 0;
+               if (sp->unsync) {
+                       kvm_unlink_unsync_global(vcpu->kvm, sp);
+                       kvm_mmu_mark_parents_unsync(vcpu, sp);
+               }
+       }
 
        /*
         * We don't set the accessed bit, since we sometimes want to see
@@ -1575,8 +1698,13 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
        if (largepage)
                spte |= PT_PAGE_SIZE_MASK;
        if (mt_mask) {
-               mt_mask = get_memory_type(vcpu, gfn) <<
-                         kvm_x86_ops->get_mt_mask_shift();
+               if (!kvm_is_mmio_pfn(pfn)) {
+                       mt_mask = get_memory_type(vcpu, gfn) <<
+                               kvm_x86_ops->get_mt_mask_shift();
+                       mt_mask |= VMX_EPT_IGMT_BIT;
+               } else
+                       mt_mask = MTRR_TYPE_UNCACHABLE <<
+                               kvm_x86_ops->get_mt_mask_shift();
                spte |= mt_mask;
        }
 
@@ -1593,6 +1721,15 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *shadow_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);
@@ -1614,8 +1751,8 @@ set_pte:
 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, int largepage, gfn_t gfn,
-                        pfn_t pfn, bool speculative)
+                        int *ptwrite, int largepage, int global,
+                        gfn_t gfn, pfn_t pfn, bool speculative)
 {
        int was_rmapped = 0;
        int was_writeble = is_writeble_pte(*shadow_pte);
@@ -1648,7 +1785,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
                }
        }
        if (set_spte(vcpu, shadow_pte, pte_access, user_fault, write_fault,
-                     dirty, largepage, gfn, pfn, speculative, true)) {
+                     dirty, largepage, global, gfn, pfn, speculative, true)) {
                if (write_fault)
                        *ptwrite = 1;
                kvm_x86_ops->tlb_flush(vcpu);
@@ -1705,7 +1842,7 @@ static int direct_map_entry(struct kvm_shadow_walk *_walk,
            || (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);
+                            walk->largepage, 0, gfn, walk->pfn, false);
                ++vcpu->stat.pf_fixed;
                return 1;
        }
@@ -1892,6 +2029,15 @@ static void mmu_sync_roots(struct kvm_vcpu *vcpu)
        }
 }
 
+static void mmu_sync_global(struct kvm_vcpu *vcpu)
+{
+       struct kvm *kvm = vcpu->kvm;
+       struct kvm_mmu_page *sp, *n;
+
+       list_for_each_entry_safe(sp, n, &kvm->arch.oos_global_pages, oos_link)
+               kvm_sync_page(vcpu, sp);
+}
+
 void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
 {
        spin_lock(&vcpu->kvm->mmu_lock);
@@ -1899,6 +2045,13 @@ void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
        spin_unlock(&vcpu->kvm->mmu_lock);
 }
 
+void kvm_mmu_sync_global(struct kvm_vcpu *vcpu)
+{
+       spin_lock(&vcpu->kvm->mmu_lock);
+       mmu_sync_global(vcpu);
+       spin_unlock(&vcpu->kvm->mmu_lock);
+}
+
 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
 {
        return vaddr;
@@ -2297,7 +2450,8 @@ static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
 }
 
 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
-                      const u8 *new, int bytes)
+                      const u8 *new, int bytes,
+                      bool guest_initiated)
 {
        gfn_t gfn = gpa >> PAGE_SHIFT;
        struct kvm_mmu_page *sp;
@@ -2323,15 +2477,17 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
        kvm_mmu_free_some_pages(vcpu);
        ++vcpu->kvm->stat.mmu_pte_write;
        kvm_mmu_audit(vcpu, "pre pte write");
-       if (gfn == vcpu->arch.last_pt_write_gfn
-           && !last_updated_pte_accessed(vcpu)) {
-               ++vcpu->arch.last_pt_write_count;
-               if (vcpu->arch.last_pt_write_count >= 3)
-                       flooded = 1;
-       } else {
-               vcpu->arch.last_pt_write_gfn = gfn;
-               vcpu->arch.last_pt_write_count = 1;
-               vcpu->arch.last_pte_updated = NULL;
+       if (guest_initiated) {
+               if (gfn == vcpu->arch.last_pt_write_gfn
+                   && !last_updated_pte_accessed(vcpu)) {
+                       ++vcpu->arch.last_pt_write_count;
+                       if (vcpu->arch.last_pt_write_count >= 3)
+                               flooded = 1;
+               } else {
+                       vcpu->arch.last_pt_write_gfn = gfn;
+                       vcpu->arch.last_pt_write_count = 1;
+                       vcpu->arch.last_pte_updated = NULL;
+               }
        }
        index = kvm_page_table_hashfn(gfn);
        bucket = &vcpu->kvm->arch.mmu_page_hash[index];
@@ -2471,9 +2627,7 @@ 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;
 }