1 files changed, 62 insertions, 106 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 01d7c2ad..4ed3edb 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -448,7 +448,8 @@ static bool __check_direct_spte_mmio_pf(u64 spte)
 
 static bool spte_is_locklessly_modifiable(u64 spte)
 {
-	return !(~spte & (SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE));
+	return (spte & (SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE)) ==
+		(SPTE_HOST_WRITEABLE | SPTE_MMU_WRITEABLE);
 }
 
 static bool spte_has_volatile_bits(u64 spte)
@@ -831,8 +832,7 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn)
 	if (host_level == PT_PAGE_TABLE_LEVEL)
 		return host_level;
 
-	max_level = kvm_x86_ops->get_lpage_level() < host_level ?
-		kvm_x86_ops->get_lpage_level() : host_level;
+	max_level = min(kvm_x86_ops->get_lpage_level(), host_level);
 
 	for (level = PT_DIRECTORY_LEVEL; level <= max_level; ++level)
 		if (has_wrprotected_page(vcpu->kvm, large_gfn, level))
@@ -1142,7 +1142,7 @@ spte_write_protect(struct kvm *kvm, u64 *sptep, bool *flush, bool pt_protect)
 }
 
 static bool __rmap_write_protect(struct kvm *kvm, unsigned long *rmapp,
-				 int level, bool pt_protect)
+				 bool pt_protect)
 {
 	u64 *sptep;
 	struct rmap_iterator iter;
@@ -1180,7 +1180,7 @@ void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
 	while (mask) {
 		rmapp = __gfn_to_rmap(slot->base_gfn + gfn_offset + __ffs(mask),
 				      PT_PAGE_TABLE_LEVEL, slot);
-		__rmap_write_protect(kvm, rmapp, PT_PAGE_TABLE_LEVEL, false);
+		__rmap_write_protect(kvm, rmapp, false);
 
 		/* clear the first set bit */
 		mask &= mask - 1;
@@ -1199,7 +1199,7 @@ static bool rmap_write_protect(struct kvm *kvm, u64 gfn)
 	for (i = PT_PAGE_TABLE_LEVEL;
 	     i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
 		rmapp = __gfn_to_rmap(gfn, i, slot);
-		write_protected |= __rmap_write_protect(kvm, rmapp, i, true);
+		write_protected |= __rmap_write_protect(kvm, rmapp, true);
 	}
 
 	return write_protected;
@@ -1460,28 +1460,14 @@ static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, int nr)
 	percpu_counter_add(&kvm_total_used_mmu_pages, nr);
 }
 
-/*
- * Remove the sp from shadow page cache, after call it,
- * we can not find this sp from the cache, and the shadow
- * page table is still valid.
- * It should be under the protection of mmu lock.
- */
-static void kvm_mmu_isolate_page(struct kvm_mmu_page *sp)
+static void kvm_mmu_free_page(struct kvm_mmu_page *sp)
 {
 	ASSERT(is_empty_shadow_page(sp->spt));
 	hlist_del(&sp->hash_link);
-	if (!sp->role.direct)
-		free_page((unsigned long)sp->gfns);
-}
-
-/*
- * Free the shadow page table and the sp, we can do it
- * out of the protection of mmu lock.
- */
-static void kvm_mmu_free_page(struct kvm_mmu_page *sp)
-{
 	list_del(&sp->link);
 	free_page((unsigned long)sp->spt);
+	if (!sp->role.direct)
+		free_page((unsigned long)sp->gfns);
 	kmem_cache_free(mmu_page_header_cache, sp);
 }
 
@@ -1522,7 +1508,6 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
 		sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache);
 	set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
 	list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
-	bitmap_zero(sp->slot_bitmap, KVM_MEM_SLOTS_NUM);
 	sp->parent_ptes = 0;
 	mmu_page_add_parent_pte(vcpu, sp, parent_pte);
 	kvm_mod_used_mmu_pages(vcpu->kvm, +1);
@@ -1973,9 +1958,9 @@ static void link_shadow_page(u64 *sptep, struct kvm_mmu_page *sp)
 {
 	u64 spte;
 
-	spte = __pa(sp->spt)
-		| PT_PRESENT_MASK | PT_ACCESSED_MASK
-		| PT_WRITABLE_MASK | PT_USER_MASK;
+	spte = __pa(sp->spt) | PT_PRESENT_MASK | PT_WRITABLE_MASK |
+	       shadow_user_mask | shadow_x_mask | shadow_accessed_mask;
+
 	mmu_spte_set(sptep, spte);
 }
 
@@ -2126,7 +2111,6 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm,
 	do {
 		sp = list_first_entry(invalid_list, struct kvm_mmu_page, link);
 		WARN_ON(!sp->role.invalid || sp->root_count);
-		kvm_mmu_isolate_page(sp);
 		kvm_mmu_free_page(sp);
 	} while (!list_empty(invalid_list));
 }
@@ -2144,6 +2128,8 @@ void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int goal_nr_mmu_pages)
 	 * change the value
 	 */
 
+	spin_lock(&kvm->mmu_lock);
+
 	if (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages) {
 		while (kvm->arch.n_used_mmu_pages > goal_nr_mmu_pages &&
 			!list_empty(&kvm->arch.active_mmu_pages)) {
@@ -2158,6 +2144,8 @@ void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int goal_nr_mmu_pages)
 	}
 
 	kvm->arch.n_max_mmu_pages = goal_nr_mmu_pages;
+
+	spin_unlock(&kvm->mmu_lock);
 }
 
 int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
@@ -2183,14 +2171,6 @@ int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page);
 
-static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
-{
-	int slot = memslot_id(kvm, gfn);
-	struct kvm_mmu_page *sp = page_header(__pa(pte));
-
-	__set_bit(slot, sp->slot_bitmap);
-}
-
 /*
  * The function is based on mtrr_type_lookup() in
  * arch/x86/kernel/cpu/mtrr/generic.c
@@ -2332,9 +2312,8 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
 		if (s->role.level != PT_PAGE_TABLE_LEVEL)
 			return 1;
 
-		if (!need_unsync && !s->unsync) {
+		if (!s->unsync)
 			need_unsync = true;
-		}
 	}
 	if (need_unsync)
 		kvm_unsync_pages(vcpu, gfn);
@@ -2342,8 +2321,7 @@ static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
 }
 
 static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
-		    unsigned pte_access, int user_fault,
-		    int write_fault, int level,
+		    unsigned pte_access, int level,
 		    gfn_t gfn, pfn_t pfn, bool speculative,
 		    bool can_unsync, bool host_writable)
 {
@@ -2378,20 +2356,13 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
 
 	spte |= (u64)pfn << PAGE_SHIFT;
 
-	if ((pte_access & ACC_WRITE_MASK)
-	    || (!vcpu->arch.mmu.direct_map && write_fault
-		&& !is_write_protection(vcpu) && !user_fault)) {
+	if (pte_access & ACC_WRITE_MASK) {
 
 		/*
-		 * There are two cases:
-		 * - the one is other vcpu creates new sp in the window
-		 *   between mapping_level() and acquiring mmu-lock.
-		 * - the another case is the new sp is created by itself
-		 *   (page-fault path) when guest uses the target gfn as
-		 *   its page table.
-		 * Both of these cases can be fixed by allowing guest to
-		 * retry the access, it will refault, then we can establish
-		 * the mapping by using small page.
+		 * Other vcpu creates new sp in the window between
+		 * mapping_level() and acquiring mmu-lock. We can
+		 * allow guest to retry the access, the mapping can
+		 * be fixed if guest refault.
 		 */
 		if (level > PT_PAGE_TABLE_LEVEL &&
 		    has_wrprotected_page(vcpu->kvm, gfn, level))
@@ -2399,19 +2370,6 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
 
 		spte |= PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE;
 
-		if (!vcpu->arch.mmu.direct_map
-		    && !(pte_access & ACC_WRITE_MASK)) {
-			spte &= ~PT_USER_MASK;
-			/*
-			 * If we converted a user page to a kernel page,
-			 * so that the kernel can write to it when cr0.wp=0,
-			 * then we should prevent the kernel from executing it
-			 * if SMEP is enabled.
-			 */
-			if (kvm_read_cr4_bits(vcpu, X86_CR4_SMEP))
-				spte |= PT64_NX_MASK;
-		}
-
 		/*
 		 * Optimization: for pte sync, if spte was writable the hash
 		 * lookup is unnecessary (and expensive). Write protection
@@ -2441,19 +2399,15 @@ done:
 }
 
 static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
-			 unsigned pt_access, unsigned pte_access,
-			 int user_fault, int write_fault,
-			 int *emulate, int level, gfn_t gfn,
-			 pfn_t pfn, bool speculative,
+			 unsigned pte_access, int write_fault, int *emulate,
+			 int level, gfn_t gfn, pfn_t pfn, bool speculative,
 			 bool host_writable)
 {
 	int was_rmapped = 0;
 	int rmap_count;
 
-	pgprintk("%s: spte %llx access %x write_fault %d"
-		 " user_fault %d gfn %llx\n",
-		 __func__, *sptep, pt_access,
-		 write_fault, user_fault, gfn);
+	pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__,
+		 *sptep, write_fault, gfn);
 
 	if (is_rmap_spte(*sptep)) {
 		/*
@@ -2477,9 +2431,8 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
 			was_rmapped = 1;
 	}
 
-	if (set_spte(vcpu, sptep, pte_access, user_fault, write_fault,
-		      level, gfn, pfn, speculative, true,
-		      host_writable)) {
+	if (set_spte(vcpu, sptep, pte_access, level, gfn, pfn, speculative,
+	      true, host_writable)) {
 		if (write_fault)
 			*emulate = 1;
 		kvm_mmu_flush_tlb(vcpu);
@@ -2497,7 +2450,6 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
 		++vcpu->kvm->stat.lpages;
 
 	if (is_shadow_present_pte(*sptep)) {
-		page_header_update_slot(vcpu->kvm, sptep, gfn);
 		if (!was_rmapped) {
 			rmap_count = rmap_add(vcpu, sptep, gfn);
 			if (rmap_count > RMAP_RECYCLE_THRESHOLD)
@@ -2571,10 +2523,9 @@ static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu,
 		return -1;
 
 	for (i = 0; i < ret; i++, gfn++, start++)
-		mmu_set_spte(vcpu, start, ACC_ALL,
-			     access, 0, 0, NULL,
-			     sp->role.level, gfn,
-			     page_to_pfn(pages[i]), true, true);
+		mmu_set_spte(vcpu, start, access, 0, NULL,
+			     sp->role.level, gfn, page_to_pfn(pages[i]),
+			     true, true);
 
 	return 0;
 }
@@ -2633,11 +2584,9 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
 
 	for_each_shadow_entry(vcpu, (u64)gfn << PAGE_SHIFT, iterator) {
 		if (iterator.level == level) {
-			unsigned pte_access = ACC_ALL;
-
-			mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, pte_access,
-				     0, write, &emulate,
-				     level, gfn, pfn, prefault, map_writable);
+			mmu_set_spte(vcpu, iterator.sptep, ACC_ALL,
+				     write, &emulate, level, gfn, pfn,
+				     prefault, map_writable);
 			direct_pte_prefetch(vcpu, iterator.sptep);
 			++vcpu->stat.pf_fixed;
 			break;
@@ -2652,11 +2601,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
 					      iterator.level - 1,
 					      1, ACC_ALL, iterator.sptep);
 
-			mmu_spte_set(iterator.sptep,
-				     __pa(sp->spt)
-				     | PT_PRESENT_MASK | PT_WRITABLE_MASK
-				     | shadow_user_mask | shadow_x_mask
-				     | shadow_accessed_mask);
+			link_shadow_page(iterator.sptep, sp);
 		}
 	}
 	return emulate;
@@ -3719,6 +3664,7 @@ int kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context)
 	else
 		r = paging32_init_context(vcpu, context);
 
+	vcpu->arch.mmu.base_role.nxe = is_nx(vcpu);
 	vcpu->arch.mmu.base_role.cr4_pae = !!is_pae(vcpu);
 	vcpu->arch.mmu.base_role.cr0_wp  = is_write_protection(vcpu);
 	vcpu->arch.mmu.base_role.smep_andnot_wp
@@ -3885,7 +3831,7 @@ static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa,
 		/* Handle a 32-bit guest writing two halves of a 64-bit gpte */
 		*gpa &= ~(gpa_t)7;
 		*bytes = 8;
-		r = kvm_read_guest(vcpu->kvm, *gpa, &gentry, min(*bytes, 8));
+		r = kvm_read_guest(vcpu->kvm, *gpa, &gentry, 8);
 		if (r)
 			gentry = 0;
 		new = (const u8 *)&gentry;
@@ -4039,7 +3985,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
 			      !((sp->role.word ^ vcpu->arch.mmu.base_role.word)
 			      & mask.word) && rmap_can_add(vcpu))
 				mmu_pte_write_new_pte(vcpu, sp, spte, &gentry);
-			if (!remote_flush && need_remote_flush(entry, *spte))
+			if (need_remote_flush(entry, *spte))
 				remote_flush = true;
 			++spte;
 		}
@@ -4198,26 +4144,36 @@ int kvm_mmu_setup(struct kvm_vcpu *vcpu)
 
 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
 {
-	struct kvm_mmu_page *sp;
-	bool flush = false;
+	struct kvm_memory_slot *memslot;
+	gfn_t last_gfn;
+	int i;
 
-	list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
-		int i;
-		u64 *pt;
+	memslot = id_to_memslot(kvm->memslots, slot);
+	last_gfn = memslot->base_gfn + memslot->npages - 1;
 
-		if (!test_bit(slot, sp->slot_bitmap))
-			continue;
+	spin_lock(&kvm->mmu_lock);
 
-		pt = sp->spt;
-		for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
-			if (!is_shadow_present_pte(pt[i]) ||
-			      !is_last_spte(pt[i], sp->role.level))
-				continue;
+	for (i = PT_PAGE_TABLE_LEVEL;
+	     i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
+		unsigned long *rmapp;
+		unsigned long last_index, index;
 
-			spte_write_protect(kvm, &pt[i], &flush, false);
+		rmapp = memslot->arch.rmap[i - PT_PAGE_TABLE_LEVEL];
+		last_index = gfn_to_index(last_gfn, memslot->base_gfn, i);
+
+		for (index = 0; index <= last_index; ++index, ++rmapp) {
+			if (*rmapp)
+				__rmap_write_protect(kvm, rmapp, false);
+
+			if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {
+				kvm_flush_remote_tlbs(kvm);
+				cond_resched_lock(&kvm->mmu_lock);
+			}
 		}
 	}
+
 	kvm_flush_remote_tlbs(kvm);
+	spin_unlock(&kvm->mmu_lock);
 }
 
 void kvm_mmu_zap_all(struct kvm *kvm)