KVM: x86/mmu: replace shadow_root_level with root_role.level

root_role.level is always the same value as shadow_level:

- it's kvm_mmu_get_tdp_level(vcpu) when going through init_kvm_tdp_mmu

- it's the level argument when going through kvm_init_shadow_ept_mmu

- it's assigned directly from new_role.base.level when going
  through shadow_mmu_init_context

Remove the duplication and get the level directly from the role.
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -439,7 +439,6 @@ struct kvm_mmu {
 	union kvm_cpu_role cpu_role;
 	union kvm_mmu_page_role root_role;
 	u8 root_level;
-	u8 shadow_root_level;
 	bool direct_map;
 
 	/*

arch/x86/kvm/mmu.h

@@ -138,7 +138,7 @@ static inline void kvm_mmu_load_pgd(struct kvm_vcpu *vcpu)
 		return;
 
 	static_call(kvm_x86_load_mmu_pgd)(vcpu, root_hpa,
-					  vcpu->arch.mmu->shadow_root_level);
+					  vcpu->arch.mmu->root_role.level);
 }
 
 struct kvm_page_fault {

arch/x86/kvm/mmu/mmu.c

@@ -2129,7 +2129,7 @@ static void shadow_walk_init_using_root(struct kvm_shadow_walk_iterator *iterato
 {
 	iterator->addr = addr;
 	iterator->shadow_addr = root;
-	iterator->level = vcpu->arch.mmu->shadow_root_level;
+	iterator->level = vcpu->arch.mmu->root_role.level;
 
 	if (iterator->level >= PT64_ROOT_4LEVEL &&
 	    vcpu->arch.mmu->root_level < PT64_ROOT_4LEVEL &&
@@ -3367,7 +3367,7 @@ static hpa_t mmu_alloc_root(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gva,
 static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
 {
 	struct kvm_mmu *mmu = vcpu->arch.mmu;
-	u8 shadow_root_level = mmu->shadow_root_level;
+	u8 shadow_root_level = mmu->root_role.level;
 	hpa_t root;
 	unsigned i;
 	int r;
@@ -3517,7 +3517,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
 	 */
 	if (mmu->root_level >= PT64_ROOT_4LEVEL) {
 		root = mmu_alloc_root(vcpu, root_gfn, 0,
-				      mmu->shadow_root_level, false);
+				      mmu->root_role.level, false);
 		mmu->root.hpa = root;
 		goto set_root_pgd;
 	}
@@ -3533,7 +3533,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
 	 * the shadow page table may be a PAE or a long mode page table.
 	 */
 	pm_mask = PT_PRESENT_MASK | shadow_me_mask;
-	if (mmu->shadow_root_level >= PT64_ROOT_4LEVEL) {
+	if (mmu->root_role.level >= PT64_ROOT_4LEVEL) {
 		pm_mask |= PT_ACCESSED_MASK | PT_WRITABLE_MASK | PT_USER_MASK;
 
 		if (WARN_ON_ONCE(!mmu->pml4_root)) {
@@ -3542,7 +3542,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
 		}
 		mmu->pml4_root[0] = __pa(mmu->pae_root) | pm_mask;
 
-		if (mmu->shadow_root_level == PT64_ROOT_5LEVEL) {
+		if (mmu->root_role.level == PT64_ROOT_5LEVEL) {
 			if (WARN_ON_ONCE(!mmu->pml5_root)) {
 				r = -EIO;
 				goto out_unlock;
@@ -3567,9 +3567,9 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
 		mmu->pae_root[i] = root | pm_mask;
 	}
 
-	if (mmu->shadow_root_level == PT64_ROOT_5LEVEL)
+	if (mmu->root_role.level == PT64_ROOT_5LEVEL)
 		mmu->root.hpa = __pa(mmu->pml5_root);
-	else if (mmu->shadow_root_level == PT64_ROOT_4LEVEL)
+	else if (mmu->root_role.level == PT64_ROOT_4LEVEL)
 		mmu->root.hpa = __pa(mmu->pml4_root);
 	else
 		mmu->root.hpa = __pa(mmu->pae_root);
@@ -3585,7 +3585,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
 static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu)
 {
 	struct kvm_mmu *mmu = vcpu->arch.mmu;
-	bool need_pml5 = mmu->shadow_root_level > PT64_ROOT_4LEVEL;
+	bool need_pml5 = mmu->root_role.level > PT64_ROOT_4LEVEL;
 	u64 *pml5_root = NULL;
 	u64 *pml4_root = NULL;
 	u64 *pae_root;
@@ -3597,7 +3597,7 @@ static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu)
 	 * on demand, as running a 32-bit L1 VMM on 64-bit KVM is very rare.
 	 */
 	if (mmu->direct_map || mmu->root_level >= PT64_ROOT_4LEVEL ||
-	    mmu->shadow_root_level < PT64_ROOT_4LEVEL)
+	    mmu->root_role.level < PT64_ROOT_4LEVEL)
 		return 0;
 
 	/*
@@ -4489,18 +4489,18 @@ static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu,
 	struct rsvd_bits_validate *shadow_zero_check;
 	int i;
 
-	WARN_ON_ONCE(context->shadow_root_level < PT32E_ROOT_LEVEL);
+	WARN_ON_ONCE(context->root_role.level < PT32E_ROOT_LEVEL);
 
 	shadow_zero_check = &context->shadow_zero_check;
 	__reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(),
-				context->shadow_root_level,
+				context->root_role.level,
 				context->root_role.efer_nx,
 				guest_can_use_gbpages(vcpu), is_pse, is_amd);
 
 	if (!shadow_me_mask)
 		return;
 
-	for (i = context->shadow_root_level; --i >= 0;) {
+	for (i = context->root_role.level; --i >= 0;) {
 		shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask;
 		shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask;
 	}
@@ -4527,7 +4527,7 @@ reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context)
 
 	if (boot_cpu_is_amd())
 		__reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(),
-					context->shadow_root_level, false,
+					context->root_role.level, false,
 					boot_cpu_has(X86_FEATURE_GBPAGES),
 					false, true);
 	else
@@ -4538,7 +4538,7 @@ reset_tdp_shadow_zero_bits_mask(struct kvm_mmu *context)
 	if (!shadow_me_mask)
 		return;
 
-	for (i = context->shadow_root_level; --i >= 0;) {
+	for (i = context->root_role.level; --i >= 0;) {
 		shadow_zero_check->rsvd_bits_mask[0][i] &= ~shadow_me_mask;
 		shadow_zero_check->rsvd_bits_mask[1][i] &= ~shadow_me_mask;
 	}
@@ -4822,7 +4822,6 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu,
 	context->page_fault = kvm_tdp_page_fault;
 	context->sync_page = nonpaging_sync_page;
 	context->invlpg = NULL;
-	context->shadow_root_level = kvm_mmu_get_tdp_level(vcpu);
 	context->direct_map = true;
 	context->get_guest_pgd = get_cr3;
 	context->get_pdptr = kvm_pdptr_read;
@@ -4860,8 +4859,6 @@ static void shadow_mmu_init_context(struct kvm_vcpu *vcpu, struct kvm_mmu *conte
 	context->root_level = cpu_role.base.level;
 
 	reset_guest_paging_metadata(vcpu, context);
-	context->shadow_root_level = root_role.level;
-
 	reset_shadow_zero_bits_mask(vcpu, context);
 }
 
@@ -4953,8 +4950,6 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
 		context->cpu_role.as_u64 = new_mode.as_u64;
 		context->root_role.word = new_mode.base.word;
 
-		context->shadow_root_level = level;
-
 		context->page_fault = ept_page_fault;
 		context->gva_to_gpa = ept_gva_to_gpa;
 		context->sync_page = ept_sync_page;

arch/x86/kvm/mmu/tdp_mmu.c

@@ -1835,7 +1835,7 @@ int kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes,
 	gfn_t gfn = addr >> PAGE_SHIFT;
 	int leaf = -1;
 
-	*root_level = vcpu->arch.mmu->shadow_root_level;
+	*root_level = vcpu->arch.mmu->root_role.level;
 
 	tdp_mmu_for_each_pte(iter, mmu, gfn, gfn + 1) {
 		leaf = iter.level;

arch/x86/kvm/svm/svm.c

@@ -3951,7 +3951,7 @@ 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->shadow_root_level >= PT64_ROOT_4LEVEL) {
+	} else if (vcpu->arch.mmu->root_role.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. */

arch/x86/kvm/vmx/vmx.c

@@ -2948,7 +2948,7 @@ static void vmx_flush_tlb_current(struct kvm_vcpu *vcpu)
 
 	if (enable_ept)
 		ept_sync_context(construct_eptp(vcpu, root_hpa,
-						mmu->shadow_root_level));
+						mmu->root_role.level));
 	else
 		vpid_sync_context(vmx_get_current_vpid(vcpu));
 }