KVM: x86/mmu: Use MMU's role/role_regs to compute context's metadata

Use the MMU's role and role_regs to calculate the MMU's guest root level
and NX bit.  For some flows, the vCPU state may not be correct (or
relevant), e.g. EPT doesn't interact with EFER.NX and nested NPT will
configure the guest_mmu with possibly-stale vCPU state.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210622175739.3610207-37-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu/mmu.c

@@ -3948,8 +3948,7 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
 				 max_level, true);
 }
 
-static void nonpaging_init_context(struct kvm_vcpu *vcpu,
-				   struct kvm_mmu *context)
+static void nonpaging_init_context(struct kvm_mmu *context)
 {
 	context->page_fault = nonpaging_page_fault;
 	context->gva_to_gpa = nonpaging_gva_to_gpa;
@@ -4513,14 +4512,13 @@ static void update_last_nonleaf_level(struct kvm_mmu *mmu)
 		mmu->last_nonleaf_level++;
 }
 
-static void paging64_init_context_common(struct kvm_vcpu *vcpu,
-					 struct kvm_mmu *context,
+static void paging64_init_context_common(struct kvm_mmu *context,
 					 int root_level)
 {
-	context->nx = is_nx(vcpu);
+	context->nx = is_efer_nx(context);
 	context->root_level = root_level;
 
-	MMU_WARN_ON(!is_pae(vcpu));
+	WARN_ON_ONCE(!is_cr4_pae(context));
 	context->page_fault = paging64_page_fault;
 	context->gva_to_gpa = paging64_gva_to_gpa;
 	context->sync_page = paging64_sync_page;
@@ -4528,17 +4526,16 @@ static void paging64_init_context_common(struct kvm_vcpu *vcpu,
 	context->direct_map = false;
 }
 
-static void paging64_init_context(struct kvm_vcpu *vcpu,
-				  struct kvm_mmu *context)
+static void paging64_init_context(struct kvm_mmu *context,
+				  struct kvm_mmu_role_regs *regs)
 {
-	int root_level = is_la57_mode(vcpu) ?
-			 PT64_ROOT_5LEVEL : PT64_ROOT_4LEVEL;
+	int root_level = ____is_cr4_la57(regs) ? PT64_ROOT_5LEVEL :
+						 PT64_ROOT_4LEVEL;
 
-	paging64_init_context_common(vcpu, context, root_level);
+	paging64_init_context_common(context, root_level);
 }
 
-static void paging32_init_context(struct kvm_vcpu *vcpu,
-				  struct kvm_mmu *context)
+static void paging32_init_context(struct kvm_mmu *context)
 {
 	context->nx = false;
 	context->root_level = PT32_ROOT_LEVEL;
@@ -4549,10 +4546,9 @@ static void paging32_init_context(struct kvm_vcpu *vcpu,
 	context->direct_map = false;
 }
 
-static void paging32E_init_context(struct kvm_vcpu *vcpu,
-				   struct kvm_mmu *context)
+static void paging32E_init_context(struct kvm_mmu *context)
 {
-	paging64_init_context_common(vcpu, context, PT32E_ROOT_LEVEL);
+	paging64_init_context_common(context, PT32E_ROOT_LEVEL);
 }
 
 static union kvm_mmu_extended_role kvm_calc_mmu_role_ext(struct kvm_vcpu *vcpu,
@@ -4712,13 +4708,13 @@ static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *conte
 	context->mmu_role.as_u64 = new_role.as_u64;
 
 	if (!____is_cr0_pg(regs))
-		nonpaging_init_context(vcpu, context);
+		nonpaging_init_context(context);
 	else if (____is_efer_lma(regs))
-		paging64_init_context(vcpu, context);
+		paging64_init_context(context, regs);
 	else if (____is_cr4_pae(regs))
-		paging32E_init_context(vcpu, context);
+		paging32E_init_context(context);
 	else
-		paging32_init_context(vcpu, context);
+		paging32_init_context(context);
 
 	if (____is_cr0_pg(regs)) {
 		reset_rsvds_bits_mask(vcpu, context);