kvm: x86: Add a root_hpa parameter to kvm_mmu->invlpg()

This allows invlpg() to be called using either the active root_hpa
or the prev_root_hpa.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -354,7 +354,7 @@ struct kvm_mmu {
 			       struct x86_exception *exception);
 	int (*sync_page)(struct kvm_vcpu *vcpu,
 			 struct kvm_mmu_page *sp);
-	void (*invlpg)(struct kvm_vcpu *vcpu, gva_t gva);
+	void (*invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa);
 	void (*update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 			   u64 *spte, const void *pte);
 	hpa_t root_hpa;

arch/x86/kvm/mmu.c

@@ -189,6 +189,12 @@ static const union kvm_mmu_page_role mmu_base_role_mask = {
 	.ad_disabled = 1,
 };
 
+#define for_each_shadow_entry_using_root(_vcpu, _root, _addr, _walker)     \
+	for (shadow_walk_init_using_root(&(_walker), (_vcpu),              \
+					 (_root), (_addr));                \
+	     shadow_walk_okay(&(_walker));			           \
+	     shadow_walk_next(&(_walker)))
+
 #define for_each_shadow_entry(_vcpu, _addr, _walker)            \
 	for (shadow_walk_init(&(_walker), _vcpu, _addr);	\
 	     shadow_walk_okay(&(_walker));			\
@@ -1999,7 +2005,7 @@ static int nonpaging_sync_page(struct kvm_vcpu *vcpu,
 	return 0;
 }
 
-static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
+static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root)
 {
 }
 
@@ -2405,11 +2411,12 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
 	return sp;
 }
 
-static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator,
-			     struct kvm_vcpu *vcpu, u64 addr)
+static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterator,
+					struct kvm_vcpu *vcpu, hpa_t root,
+					u64 addr)
 {
 	iterator->addr = addr;
-	iterator->shadow_addr = vcpu->arch.mmu.root_hpa;
+	iterator->shadow_addr = root;
 	iterator->level = vcpu->arch.mmu.shadow_root_level;
 
 	if (iterator->level == PT64_ROOT_4LEVEL &&
@@ -2418,6 +2425,12 @@ static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator,
 		--iterator->level;
 
 	if (iterator->level == PT32E_ROOT_LEVEL) {
+		/*
+		 * prev_root is currently only used for 64-bit hosts. So only
+		 * the active root_hpa is valid here.
+		 */
+		BUG_ON(root != vcpu->arch.mmu.root_hpa);
+
 		iterator->shadow_addr
 			= vcpu->arch.mmu.pae_root[(addr >> 30) & 3];
 		iterator->shadow_addr &= PT64_BASE_ADDR_MASK;
@@ -2427,6 +2440,13 @@ static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator,
 	}
 }
 
+static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator,
+			     struct kvm_vcpu *vcpu, u64 addr)
+{
+	shadow_walk_init_using_root(iterator, vcpu, vcpu->arch.mmu.root_hpa,
+				    addr);
+}
+
 static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator)
 {
 	if (iterator->level < PT_PAGE_TABLE_LEVEL)
@@ -5186,7 +5206,9 @@ EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
 
 void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
 {
-	vcpu->arch.mmu.invlpg(vcpu, gva);
+	struct kvm_mmu *mmu = &vcpu->arch.mmu;
+
+	mmu->invlpg(vcpu, gva, mmu->root_hpa);
 	kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
 	++vcpu->stat.invlpg;
 }
@@ -5197,7 +5219,7 @@ void kvm_mmu_invpcid_gva(struct kvm_vcpu *vcpu, gva_t gva, unsigned long pcid)
 	struct kvm_mmu *mmu = &vcpu->arch.mmu;
 
 	if (pcid == kvm_get_active_pcid(vcpu)) {
-		mmu->invlpg(vcpu, gva);
+		mmu->invlpg(vcpu, gva, mmu->root_hpa);
 		kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
 	}
 

arch/x86/kvm/paging_tmpl.h

@@ -856,7 +856,7 @@ static gpa_t FNAME(get_level1_sp_gpa)(struct kvm_mmu_page *sp)
 	return gfn_to_gpa(sp->gfn) + offset * sizeof(pt_element_t);
 }
 
-static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
+static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa)
 {
 	struct kvm_shadow_walk_iterator iterator;
 	struct kvm_mmu_page *sp;
@@ -871,13 +871,13 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
 	 */
 	mmu_topup_memory_caches(vcpu);
 
-	if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) {
+	if (!VALID_PAGE(root_hpa)) {
 		WARN_ON(1);
 		return;
 	}
 
 	spin_lock(&vcpu->kvm->mmu_lock);
-	for_each_shadow_entry(vcpu, gva, iterator) {
+	for_each_shadow_entry_using_root(vcpu, root_hpa, gva, iterator) {
 		level = iterator.level;
 		sptep = iterator.sptep;