1 files changed, 283 insertions, 157 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 98f6e4f88b04..5269aa057dfa 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -140,9 +140,6 @@ module_param(dbg, bool, 0644);
 
 #include <trace/events/kvm.h>
 
-#define CREATE_TRACE_POINTS
-#include "mmutrace.h"
-
 #define SPTE_HOST_WRITEABLE	(1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
 #define SPTE_MMU_WRITEABLE	(1ULL << (PT_FIRST_AVAIL_BITS_SHIFT + 1))
 
@@ -217,6 +214,7 @@ static u64 __read_mostly shadow_accessed_mask;
 static u64 __read_mostly shadow_dirty_mask;
 static u64 __read_mostly shadow_mmio_mask;
 static u64 __read_mostly shadow_mmio_value;
+static u64 __read_mostly shadow_mmio_access_mask;
 static u64 __read_mostly shadow_present_mask;
 static u64 __read_mostly shadow_me_mask;
 
@@ -259,11 +257,20 @@ static const u64 shadow_nonpresent_or_rsvd_mask_len = 5;
  */
 static u64 __read_mostly shadow_nonpresent_or_rsvd_lower_gfn_mask;
 
+/*
+ * The number of non-reserved physical address bits irrespective of features
+ * that repurpose legal bits, e.g. MKTME.
+ */
+static u8 __read_mostly shadow_phys_bits;
 
 static void mmu_spte_set(u64 *sptep, u64 spte);
+static bool is_executable_pte(u64 spte);
 static union kvm_mmu_page_role
 kvm_mmu_calc_root_page_role(struct kvm_vcpu *vcpu);
 
+#define CREATE_TRACE_POINTS
+#include "mmutrace.h"
+
 
 static inline bool kvm_available_flush_tlb_with_range(void)
 {
@@ -293,14 +300,21 @@ static void kvm_flush_remote_tlbs_with_address(struct kvm *kvm,
 	kvm_flush_remote_tlbs_with_range(kvm, &range);
 }
 
-void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask, u64 mmio_value)
+void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask, u64 mmio_value, u64 access_mask)
 {
+	BUG_ON((u64)(unsigned)access_mask != access_mask);
 	BUG_ON((mmio_mask & mmio_value) != mmio_value);
 	shadow_mmio_value = mmio_value | SPTE_SPECIAL_MASK;
 	shadow_mmio_mask = mmio_mask | SPTE_SPECIAL_MASK;
+	shadow_mmio_access_mask = access_mask;
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask);
 
+static bool is_mmio_spte(u64 spte)
+{
+	return (spte & shadow_mmio_mask) == shadow_mmio_value;
+}
+
 static inline bool sp_ad_disabled(struct kvm_mmu_page *sp)
 {
 	return sp->role.ad_disabled;
@@ -308,19 +322,19 @@ static inline bool sp_ad_disabled(struct kvm_mmu_page *sp)
 
 static inline bool spte_ad_enabled(u64 spte)
 {
-	MMU_WARN_ON((spte & shadow_mmio_mask) == shadow_mmio_value);
+	MMU_WARN_ON(is_mmio_spte(spte));
 	return !(spte & shadow_acc_track_value);
 }
 
 static inline u64 spte_shadow_accessed_mask(u64 spte)
 {
-	MMU_WARN_ON((spte & shadow_mmio_mask) == shadow_mmio_value);
+	MMU_WARN_ON(is_mmio_spte(spte));
 	return spte_ad_enabled(spte) ? shadow_accessed_mask : 0;
 }
 
 static inline u64 spte_shadow_dirty_mask(u64 spte)
 {
-	MMU_WARN_ON((spte & shadow_mmio_mask) == shadow_mmio_value);
+	MMU_WARN_ON(is_mmio_spte(spte));
 	return spte_ad_enabled(spte) ? shadow_dirty_mask : 0;
 }
 
@@ -383,23 +397,16 @@ static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn,
 	u64 mask = generation_mmio_spte_mask(gen);
 	u64 gpa = gfn << PAGE_SHIFT;
 
-	access &= ACC_WRITE_MASK | ACC_USER_MASK;
+	access &= shadow_mmio_access_mask;
 	mask |= shadow_mmio_value | access;
 	mask |= gpa | shadow_nonpresent_or_rsvd_mask;
 	mask |= (gpa & shadow_nonpresent_or_rsvd_mask)
 		<< shadow_nonpresent_or_rsvd_mask_len;
 
-	page_header(__pa(sptep))->mmio_cached = true;
-
 	trace_mark_mmio_spte(sptep, gfn, access, gen);
 	mmu_spte_set(sptep, mask);
 }
 
-static bool is_mmio_spte(u64 spte)
-{
-	return (spte & shadow_mmio_mask) == shadow_mmio_value;
-}
-
 static gfn_t get_mmio_spte_gfn(u64 spte)
 {
 	u64 gpa = spte & shadow_nonpresent_or_rsvd_lower_gfn_mask;
@@ -412,8 +419,7 @@ static gfn_t get_mmio_spte_gfn(u64 spte)
 
 static unsigned get_mmio_spte_access(u64 spte)
 {
-	u64 mask = generation_mmio_spte_mask(MMIO_SPTE_GEN_MASK) | shadow_mmio_mask;
-	return (spte & ~mask) & ~PAGE_MASK;
+	return spte & shadow_mmio_access_mask;
 }
 
 static bool set_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn,
@@ -468,6 +474,21 @@ void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
 
+static u8 kvm_get_shadow_phys_bits(void)
+{
+	/*
+	 * boot_cpu_data.x86_phys_bits is reduced when MKTME is detected
+	 * in CPU detection code, but MKTME treats those reduced bits as
+	 * 'keyID' thus they are not reserved bits. Therefore for MKTME
+	 * we should still return physical address bits reported by CPUID.
+	 */
+	if (!boot_cpu_has(X86_FEATURE_TME) ||
+	    WARN_ON_ONCE(boot_cpu_data.extended_cpuid_level < 0x80000008))
+		return boot_cpu_data.x86_phys_bits;
+
+	return cpuid_eax(0x80000008) & 0xff;
+}
+
 static void kvm_mmu_reset_all_pte_masks(void)
 {
 	u8 low_phys_bits;
@@ -481,6 +502,8 @@ static void kvm_mmu_reset_all_pte_masks(void)
 	shadow_present_mask = 0;
 	shadow_acc_track_mask = 0;
 
+	shadow_phys_bits = kvm_get_shadow_phys_bits();
+
 	/*
 	 * If the CPU has 46 or less physical address bits, then set an
 	 * appropriate mask to guard against L1TF attacks. Otherwise, it is
@@ -650,7 +673,7 @@ static u64 __update_clear_spte_slow(u64 *sptep, u64 spte)
 
 /*
  * The idea using the light way get the spte on x86_32 guest is from
- * gup_get_pte(arch/x86/mm/gup.c).
+ * gup_get_pte (mm/gup.c).
  *
  * An spte tlb flush may be pending, because kvm_set_pte_rmapp
  * coalesces them and we are running out of the MMU lock.  Therefore
@@ -1073,10 +1096,16 @@ static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index)
 
 static void kvm_mmu_page_set_gfn(struct kvm_mmu_page *sp, int index, gfn_t gfn)
 {
-	if (sp->role.direct)
-		BUG_ON(gfn != kvm_mmu_page_get_gfn(sp, index));
-	else
+	if (!sp->role.direct) {
 		sp->gfns[index] = gfn;
+		return;
+	}
+
+	if (WARN_ON(gfn != kvm_mmu_page_get_gfn(sp, index)))
+		pr_err_ratelimited("gfn mismatch under direct page %llx "
+				   "(expected %llx, got %llx)\n",
+				   sp->gfn,
+				   kvm_mmu_page_get_gfn(sp, index), gfn);
 }
 
 /*
@@ -2066,6 +2095,13 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, int direct
 	if (!direct)
 		sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache);
 	set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
+
+	/*
+	 * active_mmu_pages must be a FIFO list, as kvm_zap_obsolete_pages()
+	 * depends on valid pages being added to the head of the list.  See
+	 * comments in kvm_zap_obsolete_pages().
+	 */
+	sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen;
 	list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
 	kvm_mod_used_mmu_pages(vcpu->kvm, +1);
 	return sp;
@@ -2215,7 +2251,7 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm,
 #define for_each_valid_sp(_kvm, _sp, _gfn)				\
 	hlist_for_each_entry(_sp,					\
 	  &(_kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(_gfn)], hash_link) \
-		if ((_sp)->role.invalid) {    \
+		if (is_obsolete_sp((_kvm), (_sp))) {			\
 		} else
 
 #define for_each_gfn_indirect_valid_sp(_kvm, _sp, _gfn)			\
@@ -2272,6 +2308,12 @@ static void kvm_mmu_audit(struct kvm_vcpu *vcpu, int point) { }
 static void mmu_audit_disable(void) { }
 #endif
 
+static bool is_obsolete_sp(struct kvm *kvm, struct kvm_mmu_page *sp)
+{
+	return sp->role.invalid ||
+	       unlikely(sp->mmu_valid_gen != kvm->arch.mmu_valid_gen);
+}
+
 static bool kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 			 struct list_head *invalid_list)
 {
@@ -2710,7 +2752,12 @@ static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm,
 	} else {
 		list_move(&sp->link, &kvm->arch.active_mmu_pages);
 
-		if (!sp->role.invalid)
+		/*
+		 * Obsolete pages cannot be used on any vCPUs, see the comment
+		 * in kvm_mmu_zap_all_fast().  Note, is_obsolete_sp() also
+		 * treats invalid shadow pages as being obsolete.
+		 */
+		if (!is_obsolete_sp(kvm, sp))
 			kvm_reload_remote_mmus(kvm);
 	}
 
@@ -3055,10 +3102,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access,
 		ret = RET_PF_EMULATE;
 
 	pgprintk("%s: setting spte %llx\n", __func__, *sptep);
-	pgprintk("instantiating %s PTE (%s) at %llx (%llx) addr %p\n",
-		 is_large_pte(*sptep)? "2MB" : "4kB",
-		 *sptep & PT_WRITABLE_MASK ? "RW" : "R", gfn,
-		 *sptep, sptep);
+	trace_kvm_mmu_set_spte(level, gfn, sptep);
 	if (!was_rmapped && is_large_pte(*sptep))
 		++vcpu->kvm->stat.lpages;
 
@@ -3070,8 +3114,6 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access,
 		}
 	}
 
-	kvm_release_pfn_clean(pfn);
-
 	return ret;
 }
 
@@ -3106,9 +3148,11 @@ static int direct_pte_prefetch_many(struct kvm_vcpu *vcpu,
 	if (ret <= 0)
 		return -1;
 
-	for (i = 0; i < ret; i++, gfn++, start++)
+	for (i = 0; i < ret; i++, gfn++, start++) {
 		mmu_set_spte(vcpu, start, access, 0, sp->role.level, gfn,
 			     page_to_pfn(pages[i]), true, true);
+		put_page(pages[i]);
+	}
 
 	return 0;
 }
@@ -3156,40 +3200,40 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep)
 	__direct_pte_prefetch(vcpu, sp, sptep);
 }
 
-static int __direct_map(struct kvm_vcpu *vcpu, int write, int map_writable,
-			int level, gfn_t gfn, kvm_pfn_t pfn, bool prefault)
+static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, int write,
+			int map_writable, int level, kvm_pfn_t pfn,
+			bool prefault)
 {
-	struct kvm_shadow_walk_iterator iterator;
+	struct kvm_shadow_walk_iterator it;
 	struct kvm_mmu_page *sp;
-	int emulate = 0;
-	gfn_t pseudo_gfn;
+	int ret;
+	gfn_t gfn = gpa >> PAGE_SHIFT;
+	gfn_t base_gfn = gfn;
 
 	if (!VALID_PAGE(vcpu->arch.mmu->root_hpa))
-		return 0;
+		return RET_PF_RETRY;
 
-	for_each_shadow_entry(vcpu, (u64)gfn << PAGE_SHIFT, iterator) {
-		if (iterator.level == level) {
-			emulate = mmu_set_spte(vcpu, iterator.sptep, ACC_ALL,
-					       write, level, gfn, pfn, prefault,
-					       map_writable);
-			direct_pte_prefetch(vcpu, iterator.sptep);
-			++vcpu->stat.pf_fixed;
+	trace_kvm_mmu_spte_requested(gpa, level, pfn);
+	for_each_shadow_entry(vcpu, gpa, it) {
+		base_gfn = gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
+		if (it.level == level)
 			break;
-		}
-
-		drop_large_spte(vcpu, iterator.sptep);
-		if (!is_shadow_present_pte(*iterator.sptep)) {
-			u64 base_addr = iterator.addr;
 
-			base_addr &= PT64_LVL_ADDR_MASK(iterator.level);
-			pseudo_gfn = base_addr >> PAGE_SHIFT;
-			sp = kvm_mmu_get_page(vcpu, pseudo_gfn, iterator.addr,
-					      iterator.level - 1, 1, ACC_ALL);
+		drop_large_spte(vcpu, it.sptep);
+		if (!is_shadow_present_pte(*it.sptep)) {
+			sp = kvm_mmu_get_page(vcpu, base_gfn, it.addr,
+					      it.level - 1, true, ACC_ALL);
 
-			link_shadow_page(vcpu, iterator.sptep, sp);
+			link_shadow_page(vcpu, it.sptep, sp);
 		}
 	}
-	return emulate;
+
+	ret = mmu_set_spte(vcpu, it.sptep, ACC_ALL,
+			   write, level, base_gfn, pfn, prefault,
+			   map_writable);
+	direct_pte_prefetch(vcpu, it.sptep);
+	++vcpu->stat.pf_fixed;
+	return ret;
 }
 
 static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *tsk)
@@ -3216,11 +3260,10 @@ static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn)
 }
 
 static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
-					gfn_t *gfnp, kvm_pfn_t *pfnp,
+					gfn_t gfn, kvm_pfn_t *pfnp,
 					int *levelp)
 {
 	kvm_pfn_t pfn = *pfnp;
-	gfn_t gfn = *gfnp;
 	int level = *levelp;
 
 	/*
@@ -3247,8 +3290,6 @@ static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu,
 		mask = KVM_PAGES_PER_HPAGE(level) - 1;
 		VM_BUG_ON((gfn & mask) != (pfn & mask));
 		if (pfn & mask) {
-			gfn &= ~mask;
-			*gfnp = gfn;
 			kvm_release_pfn_clean(pfn);
 			pfn &= ~mask;
 			kvm_get_pfn(pfn);
@@ -3267,7 +3308,8 @@ static bool handle_abnormal_pfn(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn,
 	}
 
 	if (unlikely(is_noslot_pfn(pfn)))
-		vcpu_cache_mmio_info(vcpu, gva, gfn, access);
+		vcpu_cache_mmio_info(vcpu, gva, gfn,
+				     access & shadow_mmio_access_mask);
 
 	return false;
 }
@@ -3443,7 +3485,7 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level,
 		/*
 		 * Currently, fast page fault only works for direct mapping
 		 * since the gfn is not stable for indirect shadow page. See
-		 * Documentation/virtual/kvm/locking.txt to get more detail.
+		 * Documentation/virt/kvm/locking.txt to get more detail.
 		 */
 		fault_handled = fast_pf_fix_direct_spte(vcpu, sp,
 							iterator.sptep, spte,
@@ -3505,22 +3547,19 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code,
 	if (handle_abnormal_pfn(vcpu, v, gfn, pfn, ACC_ALL, &r))
 		return r;
 
+	r = RET_PF_RETRY;
 	spin_lock(&vcpu->kvm->mmu_lock);
 	if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
 		goto out_unlock;
 	if (make_mmu_pages_available(vcpu) < 0)
 		goto out_unlock;
 	if (likely(!force_pt_level))
-		transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);
-	r = __direct_map(vcpu, write, map_writable, level, gfn, pfn, prefault);
-	spin_unlock(&vcpu->kvm->mmu_lock);
-
-	return r;
-
+		transparent_hugepage_adjust(vcpu, gfn, &pfn, &level);
+	r = __direct_map(vcpu, v, write, map_writable, level, pfn, prefault);
 out_unlock:
 	spin_unlock(&vcpu->kvm->mmu_lock);
 	kvm_release_pfn_clean(pfn);
-	return RET_PF_RETRY;
+	return r;
 }
 
 static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa,
@@ -4015,19 +4054,6 @@ static int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn)
 	return kvm_setup_async_pf(vcpu, gva, kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch);
 }
 
-bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu)
-{
-	if (unlikely(!lapic_in_kernel(vcpu) ||
-		     kvm_event_needs_reinjection(vcpu) ||
-		     vcpu->arch.exception.pending))
-		return false;
-
-	if (!vcpu->arch.apf.delivery_as_pf_vmexit && is_guest_mode(vcpu))
-		return false;
-
-	return kvm_x86_ops->interrupt_allowed(vcpu);
-}
-
 static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
 			 gva_t gva, kvm_pfn_t *pfn, bool write, bool *writable)
 {
@@ -4147,22 +4173,19 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code,
 	if (handle_abnormal_pfn(vcpu, 0, gfn, pfn, ACC_ALL, &r))
 		return r;
 
+	r = RET_PF_RETRY;
 	spin_lock(&vcpu->kvm->mmu_lock);
 	if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
 		goto out_unlock;
 	if (make_mmu_pages_available(vcpu) < 0)
 		goto out_unlock;
 	if (likely(!force_pt_level))
-		transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);
-	r = __direct_map(vcpu, write, map_writable, level, gfn, pfn, prefault);
-	spin_unlock(&vcpu->kvm->mmu_lock);
-
-	return r;
-
+		transparent_hugepage_adjust(vcpu, gfn, &pfn, &level);
+	r = __direct_map(vcpu, gpa, write, map_writable, level, pfn, prefault);
 out_unlock:
 	spin_unlock(&vcpu->kvm->mmu_lock);
 	kvm_release_pfn_clean(pfn);
-	return RET_PF_RETRY;
+	return r;
 }
 
 static void nonpaging_init_context(struct kvm_vcpu *vcpu,
@@ -4229,6 +4252,13 @@ static bool fast_cr3_switch(struct kvm_vcpu *vcpu, gpa_t new_cr3,
 			return false;
 
 		if (cached_root_available(vcpu, new_cr3, new_role)) {
+			/*
+			 * It is possible that the cached previous root page is
+			 * obsolete because of a change in the MMU generation
+			 * number. However, changing the generation number is
+			 * accompanied by KVM_REQ_MMU_RELOAD, which will free
+			 * the root set here and allocate a new one.
+			 */
 			kvm_make_request(KVM_REQ_LOAD_CR3, vcpu);
 			if (!skip_tlb_flush) {
 				kvm_make_request(KVM_REQ_MMU_SYNC, vcpu);
@@ -4494,7 +4524,7 @@ reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context)
 	 */
 	shadow_zero_check = &context->shadow_zero_check;
 	__reset_rsvds_bits_mask(vcpu, shadow_zero_check,
-				boot_cpu_data.x86_phys_bits,
+				shadow_phys_bits,
 				context->shadow_root_level, uses_nx,
 				guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES),
 				is_pse(vcpu), true);
@@ -4531,13 +4561,13 @@ reset_tdp_shadow_zero_bits_mask(struct kvm_vcpu *vcpu,
 
 	if (boot_cpu_is_amd())
 		__reset_rsvds_bits_mask(vcpu, shadow_zero_check,
-					boot_cpu_data.x86_phys_bits,
+					shadow_phys_bits,
 					context->shadow_root_level, false,
 					boot_cpu_has(X86_FEATURE_GBPAGES),
 					true, true);
 	else
 		__reset_rsvds_bits_mask_ept(shadow_zero_check,
-					    boot_cpu_data.x86_phys_bits,
+					    shadow_phys_bits,
 					    false);
 
 	if (!shadow_me_mask)
@@ -4558,7 +4588,7 @@ reset_ept_shadow_zero_bits_mask(struct kvm_vcpu *vcpu,
 				struct kvm_mmu *context, bool execonly)
 {
 	__reset_rsvds_bits_mask_ept(&context->shadow_zero_check,
-				    boot_cpu_data.x86_phys_bits, execonly);
+				    shadow_phys_bits, execonly);
 }
 
 #define BYTE_MASK(access) \
@@ -4593,11 +4623,11 @@ static void update_permission_bitmask(struct kvm_vcpu *vcpu,
 		 */
 
 		/* Faults from writes to non-writable pages */
-		u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0;
+		u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0;
 		/* Faults from user mode accesses to supervisor pages */
-		u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0;
+		u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0;
 		/* Faults from fetches of non-executable pages*/
-		u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0;
+		u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0;
 		/* Faults from kernel mode fetches of user pages */
 		u8 smepf = 0;
 		/* Faults from kernel mode accesses of user pages */
@@ -5357,7 +5387,6 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u64 error_code,
 		       void *insn, int insn_len)
 {
 	int r, emulation_type = 0;
-	enum emulation_result er;
 	bool direct = vcpu->arch.mmu->direct_map;
 
 	/* With shadow page tables, fault_address contains a GVA or nGPA.  */
@@ -5424,19 +5453,8 @@ emulate:
 			return 1;
 	}
 
-	er = x86_emulate_instruction(vcpu, cr2, emulation_type, insn, insn_len);
-
-	switch (er) {
-	case EMULATE_DONE:
-		return 1;
-	case EMULATE_USER_EXIT:
-		++vcpu->stat.mmio_exits;
-		/* fall through */
-	case EMULATE_FAIL:
-		return 0;
-	default:
-		BUG();
-	}
+	return x86_emulate_instruction(vcpu, cr2, emulation_type, insn,
+				       insn_len);
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
 
@@ -5588,13 +5606,13 @@ slot_handle_leaf(struct kvm *kvm, struct kvm_memory_slot *memslot,
 				 PT_PAGE_TABLE_LEVEL, lock_flush_tlb);
 }
 
-static void free_mmu_pages(struct kvm_vcpu *vcpu)
+static void free_mmu_pages(struct kvm_mmu *mmu)
 {
-	free_page((unsigned long)vcpu->arch.mmu->pae_root);
-	free_page((unsigned long)vcpu->arch.mmu->lm_root);
+	free_page((unsigned long)mmu->pae_root);
+	free_page((unsigned long)mmu->lm_root);
 }
 
-static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
+static int alloc_mmu_pages(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu)
 {
 	struct page *page;
 	int i;
@@ -5615,9 +5633,9 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
 	if (!page)
 		return -ENOMEM;
 
-	vcpu->arch.mmu->pae_root = page_address(page);
+	mmu->pae_root = page_address(page);
 	for (i = 0; i < 4; ++i)
-		vcpu->arch.mmu->pae_root[i] = INVALID_PAGE;
+		mmu->pae_root[i] = INVALID_PAGE;
 
 	return 0;
 }
@@ -5625,6 +5643,7 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
 int kvm_mmu_create(struct kvm_vcpu *vcpu)
 {
 	uint i;
+	int ret;
 
 	vcpu->arch.mmu = &vcpu->arch.root_mmu;
 	vcpu->arch.walk_mmu = &vcpu->arch.root_mmu;
@@ -5642,47 +5661,124 @@ int kvm_mmu_create(struct kvm_vcpu *vcpu)
 		vcpu->arch.guest_mmu.prev_roots[i] = KVM_MMU_ROOT_INFO_INVALID;
 
 	vcpu->arch.nested_mmu.translate_gpa = translate_nested_gpa;
-	return alloc_mmu_pages(vcpu);
-}
 
-static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm,
-			struct kvm_memory_slot *slot,
-			struct kvm_page_track_notifier_node *node)
-{
-	struct kvm_mmu_page *sp;
-	LIST_HEAD(invalid_list);
-	unsigned long i;
-	bool flush;
-	gfn_t gfn;
+	ret = alloc_mmu_pages(vcpu, &vcpu->arch.guest_mmu);
+	if (ret)
+		return ret;
 
-	spin_lock(&kvm->mmu_lock);
+	ret = alloc_mmu_pages(vcpu, &vcpu->arch.root_mmu);
+	if (ret)
+		goto fail_allocate_root;
 
-	if (list_empty(&kvm->arch.active_mmu_pages))
-		goto out_unlock;
+	return ret;
+ fail_allocate_root:
+	free_mmu_pages(&vcpu->arch.guest_mmu);
+	return ret;
+}
 
-	flush = slot_handle_all_level(kvm, slot, kvm_zap_rmapp, false);
+#define BATCH_ZAP_PAGES	10
+static void kvm_zap_obsolete_pages(struct kvm *kvm)
+{
+	struct kvm_mmu_page *sp, *node;
+	int nr_zapped, batch = 0;
 
-	for (i = 0; i < slot->npages; i++) {
-		gfn = slot->base_gfn + i;
+restart:
+	list_for_each_entry_safe_reverse(sp, node,
+	      &kvm->arch.active_mmu_pages, link) {
+		/*
+		 * No obsolete valid page exists before a newly created page
+		 * since active_mmu_pages is a FIFO list.
+		 */
+		if (!is_obsolete_sp(kvm, sp))
+			break;
 
-		for_each_valid_sp(kvm, sp, gfn) {
-			if (sp->gfn != gfn)
-				continue;
+		/*
+		 * Skip invalid pages with a non-zero root count, zapping pages
+		 * with a non-zero root count will never succeed, i.e. the page
+		 * will get thrown back on active_mmu_pages and we'll get stuck
+		 * in an infinite loop.
+		 */
+		if (sp->role.invalid && sp->root_count)
+			continue;
 
-			kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);
+		/*
+		 * No need to flush the TLB since we're only zapping shadow
+		 * pages with an obsolete generation number and all vCPUS have
+		 * loaded a new root, i.e. the shadow pages being zapped cannot
+		 * be in active use by the guest.
+		 */
+		if (batch >= BATCH_ZAP_PAGES &&
+		    cond_resched_lock(&kvm->mmu_lock)) {
+			batch = 0;
+			goto restart;
 		}
-		if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {
-			kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush);
-			flush = false;
-			cond_resched_lock(&kvm->mmu_lock);
+
+		if (__kvm_mmu_prepare_zap_page(kvm, sp,
+				&kvm->arch.zapped_obsolete_pages, &nr_zapped)) {
+			batch += nr_zapped;
+			goto restart;
 		}
 	}
-	kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush);
 
-out_unlock:
+	/*
+	 * Trigger a remote TLB flush before freeing the page tables to ensure
+	 * KVM is not in the middle of a lockless shadow page table walk, which
+	 * may reference the pages.
+	 */
+	kvm_mmu_commit_zap_page(kvm, &kvm->arch.zapped_obsolete_pages);
+}
+
+/*
+ * Fast invalidate all shadow pages and use lock-break technique
+ * to zap obsolete pages.
+ *
+ * It's required when memslot is being deleted or VM is being
+ * destroyed, in these cases, we should ensure that KVM MMU does
+ * not use any resource of the being-deleted slot or all slots
+ * after calling the function.
+ */
+static void kvm_mmu_zap_all_fast(struct kvm *kvm)
+{
+	lockdep_assert_held(&kvm->slots_lock);
+
+	spin_lock(&kvm->mmu_lock);
+	trace_kvm_mmu_zap_all_fast(kvm);
+
+	/*
+	 * Toggle mmu_valid_gen between '0' and '1'.  Because slots_lock is
+	 * held for the entire duration of zapping obsolete pages, it's
+	 * impossible for there to be multiple invalid generations associated
+	 * with *valid* shadow pages at any given time, i.e. there is exactly
+	 * one valid generation and (at most) one invalid generation.
+	 */
+	kvm->arch.mmu_valid_gen = kvm->arch.mmu_valid_gen ? 0 : 1;
+
+	/*
+	 * Notify all vcpus to reload its shadow page table and flush TLB.
+	 * Then all vcpus will switch to new shadow page table with the new
+	 * mmu_valid_gen.
+	 *
+	 * Note: we need to do this under the protection of mmu_lock,
+	 * otherwise, vcpu would purge shadow page but miss tlb flush.
+	 */
+	kvm_reload_remote_mmus(kvm);
+
+	kvm_zap_obsolete_pages(kvm);
 	spin_unlock(&kvm->mmu_lock);
 }
 
+static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm)
+{
+	return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages));
+}
+
+static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm,
+			struct kvm_memory_slot *slot,
+			struct kvm_page_track_notifier_node *node)
+{
+	kvm_mmu_zap_all_fast(kvm);
+}
+
 void kvm_mmu_init_vm(struct kvm *kvm)
 {
 	struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker;
@@ -5873,7 +5969,7 @@ void kvm_mmu_slot_set_dirty(struct kvm *kvm,
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_slot_set_dirty);
 
-static void __kvm_mmu_zap_all(struct kvm *kvm, bool mmio_only)
+void kvm_mmu_zap_all(struct kvm *kvm)
 {
 	struct kvm_mmu_page *sp, *node;
 	LIST_HEAD(invalid_list);
@@ -5882,14 +5978,10 @@ static void __kvm_mmu_zap_all(struct kvm *kvm, bool mmio_only)
 	spin_lock(&kvm->mmu_lock);
 restart:
 	list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) {
-		if (mmio_only && !sp->mmio_cached)
-			continue;
 		if (sp->role.invalid && sp->root_count)
 			continue;
-		if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign)) {
-			WARN_ON_ONCE(mmio_only);
+		if (__kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list, &ign))
 			goto restart;
-		}
 		if (cond_resched_lock(&kvm->mmu_lock))
 			goto restart;
 	}
@@ -5898,11 +5990,6 @@ restart:
 	spin_unlock(&kvm->mmu_lock);
 }
 
-void kvm_mmu_zap_all(struct kvm *kvm)
-{
-	return __kvm_mmu_zap_all(kvm, false);
-}
-
 void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen)
 {
 	WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS);
@@ -5924,7 +6011,7 @@ void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen)
 	 */
 	if (unlikely(gen == 0)) {
 		kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n");
-		__kvm_mmu_zap_all(kvm, true);
+		kvm_mmu_zap_all_fast(kvm);
 	}
 }
 
@@ -5935,7 +6022,7 @@ mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 	int nr_to_scan = sc->nr_to_scan;
 	unsigned long freed = 0;
 
-	spin_lock(&kvm_lock);
+	mutex_lock(&kvm_lock);
 
 	list_for_each_entry(kvm, &vm_list, vm_list) {
 		int idx;
@@ -5955,16 +6042,24 @@ mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 		 * want to shrink a VM that only started to populate its MMU
 		 * anyway.
 		 */
-		if (!kvm->arch.n_used_mmu_pages)
+		if (!kvm->arch.n_used_mmu_pages &&
+		    !kvm_has_zapped_obsolete_pages(kvm))
 			continue;
 
 		idx = srcu_read_lock(&kvm->srcu);
 		spin_lock(&kvm->mmu_lock);
 
+		if (kvm_has_zapped_obsolete_pages(kvm)) {
+			kvm_mmu_commit_zap_page(kvm,
+			      &kvm->arch.zapped_obsolete_pages);
+			goto unlock;
+		}
+
 		if (prepare_zap_oldest_mmu_page(kvm, &invalid_list))
 			freed++;
 		kvm_mmu_commit_zap_page(kvm, &invalid_list);
 
+unlock:
 		spin_unlock(&kvm->mmu_lock);
 		srcu_read_unlock(&kvm->srcu, idx);
 
@@ -5977,7 +6072,7 @@ mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 		break;
 	}
 
-	spin_unlock(&kvm_lock);
+	mutex_unlock(&kvm_lock);
 	return freed;
 }
 
@@ -5999,6 +6094,34 @@ static void mmu_destroy_caches(void)
 	kmem_cache_destroy(mmu_page_header_cache);
 }
 
+static void kvm_set_mmio_spte_mask(void)
+{
+	u64 mask;
+
+	/*
+	 * Set the reserved bits and the present bit of an paging-structure
+	 * entry to generate page fault with PFER.RSV = 1.
+	 */
+
+	/*
+	 * Mask the uppermost physical address bit, which would be reserved as
+	 * long as the supported physical address width is less than 52.
+	 */
+	mask = 1ull << 51;
+
+	/* Set the present bit. */
+	mask |= 1ull;
+
+	/*
+	 * If reserved bit is not supported, clear the present bit to disable
+	 * mmio page fault.
+	 */
+	if (IS_ENABLED(CONFIG_X86_64) && shadow_phys_bits == 52)
+		mask &= ~1ull;
+
+	kvm_mmu_set_mmio_spte_mask(mask, mask, ACC_WRITE_MASK | ACC_USER_MASK);
+}
+
 int kvm_mmu_module_init(void)
 {
 	int ret = -ENOMEM;
@@ -6015,6 +6138,8 @@ int kvm_mmu_module_init(void)
 
 	kvm_mmu_reset_all_pte_masks();
 
+	kvm_set_mmio_spte_mask();
+
 	pte_list_desc_cache = kmem_cache_create("pte_list_desc",
 					    sizeof(struct pte_list_desc),
 					    0, SLAB_ACCOUNT, NULL);
@@ -6068,7 +6193,8 @@ unsigned long kvm_mmu_calculate_default_mmu_pages(struct kvm *kvm)
 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
 {
 	kvm_mmu_unload(vcpu);
-	free_mmu_pages(vcpu);
+	free_mmu_pages(&vcpu->arch.root_mmu);
+	free_mmu_pages(&vcpu->arch.guest_mmu);
 	mmu_free_memory_caches(vcpu);
 }