KVM: MMU: introduce PT_MAX_HUGEPAGE_LEVEL

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu.c

@@ -811,8 +811,7 @@ static void account_shadowed(struct kvm *kvm, gfn_t gfn)
 	int i;
 
 	slot = gfn_to_memslot(kvm, gfn);
-	for (i = PT_DIRECTORY_LEVEL;
-	     i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
+	for (i = PT_DIRECTORY_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
 		linfo = lpage_info_slot(gfn, slot, i);
 		linfo->write_count += 1;
 	}
@@ -826,8 +825,7 @@ static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn)
 	int i;
 
 	slot = gfn_to_memslot(kvm, gfn);
-	for (i = PT_DIRECTORY_LEVEL;
-	     i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
+	for (i = PT_DIRECTORY_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
 		linfo = lpage_info_slot(gfn, slot, i);
 		linfo->write_count -= 1;
 		WARN_ON(linfo->write_count < 0);
@@ -858,8 +856,7 @@ static int host_mapping_level(struct kvm *kvm, gfn_t gfn)
 
 	page_size = kvm_host_page_size(kvm, gfn);
 
-	for (i = PT_PAGE_TABLE_LEVEL;
-	     i < (PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES); ++i) {
+	for (i = PT_PAGE_TABLE_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
 		if (page_size >= KVM_HPAGE_SIZE(i))
 			ret = i;
 		else
@@ -1344,8 +1341,7 @@ static bool rmap_write_protect(struct kvm *kvm, u64 gfn)
 
 	slot = gfn_to_memslot(kvm, gfn);
 
-	for (i = PT_PAGE_TABLE_LEVEL;
-	     i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
+	for (i = PT_PAGE_TABLE_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
 		rmapp = __gfn_to_rmap(gfn, i, slot);
 		write_protected |= __rmap_write_protect(kvm, rmapp, true);
 	}
@@ -1451,7 +1447,7 @@ static int kvm_handle_hva_range(struct kvm *kvm,
 		gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
 
 		for (j = PT_PAGE_TABLE_LEVEL;
-		     j < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++j) {
+		     j <= PT_MAX_HUGEPAGE_LEVEL; ++j) {
 			unsigned long idx, idx_end;
 			unsigned long *rmapp;
 			gfn_t gfn = gfn_start;
@@ -4416,8 +4412,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
 
 	spin_lock(&kvm->mmu_lock);
 
-	for (i = PT_PAGE_TABLE_LEVEL;
-	     i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
+	for (i = PT_PAGE_TABLE_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
 		unsigned long *rmapp;
 		unsigned long last_index, index;
 
@@ -4573,8 +4568,8 @@ void kvm_mmu_slot_largepage_remove_write_access(struct kvm *kvm,
 
 	spin_lock(&kvm->mmu_lock);
 
-	for (i = PT_PAGE_TABLE_LEVEL + 1; /* skip rmap for 4K page */
-	     i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
+	/* skip rmap for 4K page */
+	for (i = PT_PAGE_TABLE_LEVEL + 1; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
 		unsigned long *rmapp;
 		unsigned long last_index, index;
 
@@ -4611,8 +4606,7 @@ void kvm_mmu_slot_set_dirty(struct kvm *kvm,
 
 	spin_lock(&kvm->mmu_lock);
 
-	for (i = PT_PAGE_TABLE_LEVEL;
-	     i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
+	for (i = PT_PAGE_TABLE_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) {
 		unsigned long *rmapp;
 		unsigned long last_index, index;
 

arch/x86/kvm/mmu.h

@@ -43,6 +43,7 @@
 #define PT_PDPE_LEVEL 3
 #define PT_DIRECTORY_LEVEL 2
 #define PT_PAGE_TABLE_LEVEL 1
+#define PT_MAX_HUGEPAGE_LEVEL (PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES - 1)
 
 static inline u64 rsvd_bits(int s, int e)
 {