KVM: X86/SVM: Use root_level in svm_load_mmu_pgd()

Use root_level in svm_load_mmu_pg() rather that looking up the root
level in vcpu->arch.mmu->root_role.level. svm_load_mmu_pgd() has only
one caller, kvm_mmu_load_pgd(), which always passes
vcpu->arch.mmu->root_role.level as root_level.
Signed-off-by: NLai Jiangshan <jiangshan.ljs@antgroup.com>
Message-Id: <20220605063417.308311-7-jiangshanlai@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/svm.c

@@ -4049,7 +4049,7 @@ static void svm_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,
 		hv_track_root_tdp(vcpu, root_hpa);
 
 		cr3 = vcpu->arch.cr3;
-	} else if (vcpu->arch.mmu->root_role.level >= PT64_ROOT_4LEVEL) {
+	} else if (root_level >= PT64_ROOT_4LEVEL) {
 		cr3 = __sme_set(root_hpa) | kvm_get_active_pcid(vcpu);
 	} else {
 		/* PCID in the guest should be impossible with a 32-bit MMU. */