1 files changed, 115 insertions, 143 deletions

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 9d03ad4..507e2b8 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -101,11 +101,15 @@ static int FNAME(cmpxchg_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 	return (ret != orig_pte);
 }
 
-static unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, pt_element_t gpte)
+static unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, pt_element_t gpte,
+				   bool last)
 {
 	unsigned access;
 
 	access = (gpte & (PT_WRITABLE_MASK | PT_USER_MASK)) | ACC_EXEC_MASK;
+	if (last && !is_dirty_gpte(gpte))
+		access &= ~ACC_WRITE_MASK;
+
 #if PTTYPE == 64
 	if (vcpu->arch.mmu.nx)
 		access &= ~(gpte >> PT64_NX_SHIFT);
@@ -113,6 +117,24 @@ static unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, pt_element_t gpte)
 	return access;
 }
 
+static bool FNAME(is_last_gpte)(struct guest_walker *walker,
+				struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
+				pt_element_t gpte)
+{
+	if (walker->level == PT_PAGE_TABLE_LEVEL)
+		return true;
+
+	if ((walker->level == PT_DIRECTORY_LEVEL) && is_large_pte(gpte) &&
+	    (PTTYPE == 64 || is_pse(vcpu)))
+		return true;
+
+	if ((walker->level == PT_PDPE_LEVEL) && is_large_pte(gpte) &&
+	    (mmu->root_level == PT64_ROOT_LEVEL))
+		return true;
+
+	return false;
+}
+
 /*
  * Fetch a guest pte for a guest virtual address
  */
@@ -125,18 +147,17 @@ static int FNAME(walk_addr_generic)(struct guest_walker *walker,
 	gfn_t table_gfn;
 	unsigned index, pt_access, uninitialized_var(pte_access);
 	gpa_t pte_gpa;
-	bool eperm, present, rsvd_fault;
-	int offset, write_fault, user_fault, fetch_fault;
-
-	write_fault = access & PFERR_WRITE_MASK;
-	user_fault = access & PFERR_USER_MASK;
-	fetch_fault = access & PFERR_FETCH_MASK;
+	bool eperm;
+	int offset;
+	const int write_fault = access & PFERR_WRITE_MASK;
+	const int user_fault  = access & PFERR_USER_MASK;
+	const int fetch_fault = access & PFERR_FETCH_MASK;
+	u16 errcode = 0;
 
 	trace_kvm_mmu_pagetable_walk(addr, write_fault, user_fault,
 				     fetch_fault);
-walk:
-	present = true;
-	eperm = rsvd_fault = false;
+retry_walk:
+	eperm = false;
 	walker->level = mmu->root_level;
 	pte           = mmu->get_cr3(vcpu);
 
@@ -144,10 +165,8 @@ walk:
 	if (walker->level == PT32E_ROOT_LEVEL) {
 		pte = kvm_pdptr_read_mmu(vcpu, mmu, (addr >> 30) & 3);
 		trace_kvm_mmu_paging_element(pte, walker->level);
-		if (!is_present_gpte(pte)) {
-			present = false;
+		if (!is_present_gpte(pte))
 			goto error;
-		}
 		--walker->level;
 	}
 #endif
@@ -170,42 +189,31 @@ walk:
 
 		real_gfn = mmu->translate_gpa(vcpu, gfn_to_gpa(table_gfn),
 					      PFERR_USER_MASK|PFERR_WRITE_MASK);
-		if (unlikely(real_gfn == UNMAPPED_GVA)) {
-			present = false;
-			break;
-		}
+		if (unlikely(real_gfn == UNMAPPED_GVA))
+			goto error;
 		real_gfn = gpa_to_gfn(real_gfn);
 
 		host_addr = gfn_to_hva(vcpu->kvm, real_gfn);
-		if (unlikely(kvm_is_error_hva(host_addr))) {
-			present = false;
-			break;
-		}
+		if (unlikely(kvm_is_error_hva(host_addr)))
+			goto error;
 
 		ptep_user = (pt_element_t __user *)((void *)host_addr + offset);
-		if (unlikely(__copy_from_user(&pte, ptep_user, sizeof(pte)))) {
-			present = false;
-			break;
-		}
+		if (unlikely(__copy_from_user(&pte, ptep_user, sizeof(pte))))
+			goto error;
 
 		trace_kvm_mmu_paging_element(pte, walker->level);
 
-		if (unlikely(!is_present_gpte(pte))) {
-			present = false;
-			break;
-		}
+		if (unlikely(!is_present_gpte(pte)))
+			goto error;
 
 		if (unlikely(is_rsvd_bits_set(&vcpu->arch.mmu, pte,
 					      walker->level))) {
-			rsvd_fault = true;
-			break;
+			errcode |= PFERR_RSVD_MASK | PFERR_PRESENT_MASK;
+			goto error;
 		}
 
-		if (unlikely(write_fault && !is_writable_pte(pte)
-			     && (user_fault || is_write_protection(vcpu))))
-			eperm = true;
-
-		if (unlikely(user_fault && !(pte & PT_USER_MASK)))
+		if (!check_write_user_access(vcpu, write_fault, user_fault,
+					  pte))
 			eperm = true;
 
 #if PTTYPE == 64
@@ -213,39 +221,35 @@ walk:
 			eperm = true;
 #endif
 
-		if (!eperm && !rsvd_fault
-		    && unlikely(!(pte & PT_ACCESSED_MASK))) {
+		if (!eperm && unlikely(!(pte & PT_ACCESSED_MASK))) {
 			int ret;
 			trace_kvm_mmu_set_accessed_bit(table_gfn, index,
 						       sizeof(pte));
 			ret = FNAME(cmpxchg_gpte)(vcpu, mmu, ptep_user, index,
 						  pte, pte|PT_ACCESSED_MASK);
-			if (unlikely(ret < 0)) {
-				present = false;
-				break;
-			} else if (ret)
-				goto walk;
+			if (unlikely(ret < 0))
+				goto error;
+			else if (ret)
+				goto retry_walk;
 
 			mark_page_dirty(vcpu->kvm, table_gfn);
 			pte |= PT_ACCESSED_MASK;
 		}
 
-		pte_access = pt_access & FNAME(gpte_access)(vcpu, pte);
-
 		walker->ptes[walker->level - 1] = pte;
 
-		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) &&
-				mmu->root_level == PT64_ROOT_LEVEL)) {
+		if (FNAME(is_last_gpte)(walker, vcpu, mmu, pte)) {
 			int lvl = walker->level;
 			gpa_t real_gpa;
 			gfn_t gfn;
 			u32 ac;
 
+			/* check if the kernel is fetching from user page */
+			if (unlikely(pte_access & PT_USER_MASK) &&
+			    kvm_read_cr4_bits(vcpu, X86_CR4_SMEP))
+				if (fetch_fault && !user_fault)
+					eperm = true;
+
 			gfn = gpte_to_gfn_lvl(pte, lvl);
 			gfn += (addr & PT_LVL_OFFSET_MASK(lvl)) >> PAGE_SHIFT;
 
@@ -266,12 +270,14 @@ walk:
 			break;
 		}
 
-		pt_access = pte_access;
+		pt_access &= FNAME(gpte_access)(vcpu, pte, false);
 		--walker->level;
 	}
 
-	if (unlikely(!present || eperm || rsvd_fault))
+	if (unlikely(eperm)) {
+		errcode |= PFERR_PRESENT_MASK;
 		goto error;
+	}
 
 	if (write_fault && unlikely(!is_dirty_gpte(pte))) {
 		int ret;
@@ -279,17 +285,17 @@ walk:
 		trace_kvm_mmu_set_dirty_bit(table_gfn, index, sizeof(pte));
 		ret = FNAME(cmpxchg_gpte)(vcpu, mmu, ptep_user, index,
 					  pte, pte|PT_DIRTY_MASK);
-		if (unlikely(ret < 0)) {
-			present = false;
+		if (unlikely(ret < 0))
 			goto error;
-		} else if (ret)
-			goto walk;
+		else if (ret)
+			goto retry_walk;
 
 		mark_page_dirty(vcpu->kvm, table_gfn);
 		pte |= PT_DIRTY_MASK;
 		walker->ptes[walker->level - 1] = pte;
 	}
 
+	pte_access = pt_access & FNAME(gpte_access)(vcpu, pte, true);
 	walker->pt_access = pt_access;
 	walker->pte_access = pte_access;
 	pgprintk("%s: pte %llx pte_access %x pt_access %x\n",
@@ -297,19 +303,14 @@ walk:
 	return 1;
 
 error:
+	errcode |= write_fault | user_fault;
+	if (fetch_fault && (mmu->nx ||
+			    kvm_read_cr4_bits(vcpu, X86_CR4_SMEP)))
+		errcode |= PFERR_FETCH_MASK;
+
 	walker->fault.vector = PF_VECTOR;
 	walker->fault.error_code_valid = true;
-	walker->fault.error_code = 0;
-	if (present)
-		walker->fault.error_code |= PFERR_PRESENT_MASK;
-
-	walker->fault.error_code |= write_fault | user_fault;
-
-	if (fetch_fault && mmu->nx)
-		walker->fault.error_code |= PFERR_FETCH_MASK;
-	if (rsvd_fault)
-		walker->fault.error_code |= PFERR_RSVD_MASK;
-
+	walker->fault.error_code = errcode;
 	walker->fault.address = addr;
 	walker->fault.nested_page_fault = mmu != vcpu->arch.walk_mmu;
 
@@ -336,16 +337,11 @@ static bool FNAME(prefetch_invalid_gpte)(struct kvm_vcpu *vcpu,
 				    struct kvm_mmu_page *sp, u64 *spte,
 				    pt_element_t gpte)
 {
-	u64 nonpresent = shadow_trap_nonpresent_pte;
-
 	if (is_rsvd_bits_set(&vcpu->arch.mmu, gpte, PT_PAGE_TABLE_LEVEL))
 		goto no_present;
 
-	if (!is_present_gpte(gpte)) {
-		if (!sp->unsync)
-			nonpresent = shadow_notrap_nonpresent_pte;
+	if (!is_present_gpte(gpte))
 		goto no_present;
-	}
 
 	if (!(gpte & PT_ACCESSED_MASK))
 		goto no_present;
@@ -353,7 +349,7 @@ static bool FNAME(prefetch_invalid_gpte)(struct kvm_vcpu *vcpu,
 	return false;
 
 no_present:
-	drop_spte(vcpu->kvm, spte, nonpresent);
+	drop_spte(vcpu->kvm, spte);
 	return true;
 }
 
@@ -369,9 +365,9 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 		return;
 
 	pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte);
-	pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
+	pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte, true);
 	pfn = gfn_to_pfn_atomic(vcpu->kvm, gpte_to_gfn(gpte));
-	if (is_error_pfn(pfn)) {
+	if (mmu_invalid_pfn(pfn)) {
 		kvm_release_pfn_clean(pfn);
 		return;
 	}
@@ -381,7 +377,7 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 	 * vcpu->arch.update_pte.pfn was fetched from get_user_pages(write = 1).
 	 */
 	mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0,
-		     is_dirty_gpte(gpte), NULL, PT_PAGE_TABLE_LEVEL,
+		     NULL, PT_PAGE_TABLE_LEVEL,
 		     gpte_to_gfn(gpte), pfn, true, true);
 }
 
@@ -432,12 +428,11 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
 		unsigned pte_access;
 		gfn_t gfn;
 		pfn_t pfn;
-		bool dirty;
 
 		if (spte == sptep)
 			continue;
 
-		if (*spte != shadow_trap_nonpresent_pte)
+		if (is_shadow_present_pte(*spte))
 			continue;
 
 		gpte = gptep[i];
@@ -445,18 +440,18 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
 		if (FNAME(prefetch_invalid_gpte)(vcpu, sp, spte, gpte))
 			continue;
 
-		pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
+		pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte,
+								  true);
 		gfn = gpte_to_gfn(gpte);
-		dirty = is_dirty_gpte(gpte);
 		pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn,
-				      (pte_access & ACC_WRITE_MASK) && dirty);
-		if (is_error_pfn(pfn)) {
+				      pte_access & ACC_WRITE_MASK);
+		if (mmu_invalid_pfn(pfn)) {
 			kvm_release_pfn_clean(pfn);
 			break;
 		}
 
 		mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0,
-			     dirty, NULL, PT_PAGE_TABLE_LEVEL, gfn,
+			     NULL, PT_PAGE_TABLE_LEVEL, gfn,
 			     pfn, true, true);
 	}
 }
@@ -467,12 +462,11 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
 static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 			 struct guest_walker *gw,
 			 int user_fault, int write_fault, int hlevel,
-			 int *ptwrite, pfn_t pfn, bool map_writable,
+			 int *emulate, pfn_t pfn, bool map_writable,
 			 bool prefault)
 {
 	unsigned access = gw->pt_access;
 	struct kvm_mmu_page *sp = NULL;
-	bool dirty = is_dirty_gpte(gw->ptes[gw->level - 1]);
 	int top_level;
 	unsigned direct_access;
 	struct kvm_shadow_walk_iterator it;
@@ -480,9 +474,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 	if (!is_present_gpte(gw->ptes[gw->level - 1]))
 		return NULL;
 
-	direct_access = gw->pt_access & gw->pte_access;
-	if (!dirty)
-		direct_access &= ~ACC_WRITE_MASK;
+	direct_access = gw->pte_access;
 
 	top_level = vcpu->arch.mmu.root_level;
 	if (top_level == PT32E_ROOT_LEVEL)
@@ -540,8 +532,8 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 		link_shadow_page(it.sptep, sp);
 	}
 
-	mmu_set_spte(vcpu, it.sptep, access, gw->pte_access & access,
-		     user_fault, write_fault, dirty, ptwrite, it.level,
+	mmu_set_spte(vcpu, it.sptep, access, gw->pte_access,
+		     user_fault, write_fault, emulate, it.level,
 		     gw->gfn, pfn, prefault, map_writable);
 	FNAME(pte_prefetch)(vcpu, gw, it.sptep);
 
@@ -575,7 +567,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
 	int user_fault = error_code & PFERR_USER_MASK;
 	struct guest_walker walker;
 	u64 *sptep;
-	int write_pt = 0;
+	int emulate = 0;
 	int r;
 	pfn_t pfn;
 	int level = PT_PAGE_TABLE_LEVEL;
@@ -585,6 +577,10 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
 
 	pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code);
 
+	if (unlikely(error_code & PFERR_RSVD_MASK))
+		return handle_mmio_page_fault(vcpu, addr, error_code,
+					      mmu_is_nested(vcpu));
+
 	r = mmu_topup_memory_caches(vcpu);
 	if (r)
 		return r;
@@ -623,9 +619,9 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
 			 &map_writable))
 		return 0;
 
-	/* mmio */
-	if (is_error_pfn(pfn))
-		return kvm_handle_bad_page(vcpu->kvm, walker.gfn, pfn);
+	if (handle_abnormal_pfn(vcpu, mmu_is_nested(vcpu) ? 0 : addr,
+				walker.gfn, pfn, walker.pte_access, &r))
+		return r;
 
 	spin_lock(&vcpu->kvm->mmu_lock);
 	if (mmu_notifier_retry(vcpu, mmu_seq))
@@ -636,19 +632,19 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
 	if (!force_pt_level)
 		transparent_hugepage_adjust(vcpu, &walker.gfn, &pfn, &level);
 	sptep = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
-			     level, &write_pt, pfn, map_writable, prefault);
+			     level, &emulate, pfn, map_writable, prefault);
 	(void)sptep;
-	pgprintk("%s: shadow pte %p %llx ptwrite %d\n", __func__,
-		 sptep, *sptep, write_pt);
+	pgprintk("%s: shadow pte %p %llx emulate %d\n", __func__,
+		 sptep, *sptep, emulate);
 
-	if (!write_pt)
+	if (!emulate)
 		vcpu->arch.last_pt_write_count = 0; /* reset fork detector */
 
 	++vcpu->stat.pf_fixed;
 	trace_kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT);
 	spin_unlock(&vcpu->kvm->mmu_lock);
 
-	return write_pt;
+	return emulate;
 
 out_unlock:
 	spin_unlock(&vcpu->kvm->mmu_lock);
@@ -665,6 +661,8 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
 	u64 *sptep;
 	int need_flush = 0;
 
+	vcpu_clear_mmio_info(vcpu, gva);
+
 	spin_lock(&vcpu->kvm->mmu_lock);
 
 	for_each_shadow_entry(vcpu, gva, iterator) {
@@ -688,11 +686,11 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
 			if (is_shadow_present_pte(*sptep)) {
 				if (is_large_pte(*sptep))
 					--vcpu->kvm->stat.lpages;
-				drop_spte(vcpu->kvm, sptep,
-					  shadow_trap_nonpresent_pte);
+				drop_spte(vcpu->kvm, sptep);
 				need_flush = 1;
-			} else
-				__set_spte(sptep, shadow_trap_nonpresent_pte);
+			} else if (is_mmio_spte(*sptep))
+				mmu_spte_clear_no_track(sptep);
+
 			break;
 		}
 
@@ -752,36 +750,6 @@ static gpa_t FNAME(gva_to_gpa_nested)(struct kvm_vcpu *vcpu, gva_t vaddr,
 	return gpa;
 }
 
-static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
-				 struct kvm_mmu_page *sp)
-{
-	int i, j, offset, r;
-	pt_element_t pt[256 / sizeof(pt_element_t)];
-	gpa_t pte_gpa;
-
-	if (sp->role.direct
-	    || (PTTYPE == 32 && sp->role.level > PT_PAGE_TABLE_LEVEL)) {
-		nonpaging_prefetch_page(vcpu, sp);
-		return;
-	}
-
-	pte_gpa = gfn_to_gpa(sp->gfn);
-	if (PTTYPE == 32) {
-		offset = sp->role.quadrant << PT64_LEVEL_BITS;
-		pte_gpa += offset * sizeof(pt_element_t);
-	}
-
-	for (i = 0; i < PT64_ENT_PER_PAGE; i += ARRAY_SIZE(pt)) {
-		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_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
@@ -817,7 +785,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
 		gpa_t pte_gpa;
 		gfn_t gfn;
 
-		if (!is_shadow_present_pte(sp->spt[i]))
+		if (!sp->spt[i])
 			continue;
 
 		pte_gpa = first_pte_gpa + i * sizeof(pt_element_t);
@@ -826,26 +794,30 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
 					  sizeof(pt_element_t)))
 			return -EINVAL;
 
-		gfn = gpte_to_gfn(gpte);
-
 		if (FNAME(prefetch_invalid_gpte)(vcpu, sp, &sp->spt[i], gpte)) {
 			vcpu->kvm->tlbs_dirty++;
 			continue;
 		}
 
+		gfn = gpte_to_gfn(gpte);
+		pte_access = sp->role.access;
+		pte_access &= FNAME(gpte_access)(vcpu, gpte, true);
+
+		if (sync_mmio_spte(&sp->spt[i], gfn, pte_access, &nr_present))
+			continue;
+
 		if (gfn != sp->gfns[i]) {
-			drop_spte(vcpu->kvm, &sp->spt[i],
-				      shadow_trap_nonpresent_pte);
+			drop_spte(vcpu->kvm, &sp->spt[i]);
 			vcpu->kvm->tlbs_dirty++;
 			continue;
 		}
 
 		nr_present++;
-		pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
+
 		host_writable = sp->spt[i] & SPTE_HOST_WRITEABLE;
 
 		set_spte(vcpu, &sp->spt[i], pte_access, 0, 0,
-			 is_dirty_gpte(gpte), PT_PAGE_TABLE_LEVEL, gfn,
+			 PT_PAGE_TABLE_LEVEL, gfn,
 			 spte_to_pfn(sp->spt[i]), true, false,
 			 host_writable);
 	}