KVM: x86: MMU: Remove mapping_level_dirty_bitmap()

Now that it has only one caller, and its name is not so helpful for
readers, remove it.  The new memslot_valid_for_gpte() function
makes it possible to share the common code between
gfn_to_memslot_dirty_bitmap() and mapping_level().
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu.c

@@ -851,6 +851,17 @@ static int host_mapping_level(struct kvm *kvm, gfn_t gfn)
 	return ret;
 }
 
+static inline bool memslot_valid_for_gpte(struct kvm_memory_slot *slot,
+					  bool no_dirty_log)
+{
+	if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
+		return false;
+	if (no_dirty_log && slot->dirty_bitmap)
+		return false;
+
+	return true;
+}
+
 static struct kvm_memory_slot *
 gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn,
 			    bool no_dirty_log)
@@ -858,25 +869,22 @@ gfn_to_memslot_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t gfn,
 	struct kvm_memory_slot *slot;
 
 	slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
-	if (!slot || slot->flags & KVM_MEMSLOT_INVALID ||
-	      (no_dirty_log && slot->dirty_bitmap))
+	if (!memslot_valid_for_gpte(slot, no_dirty_log))
 		slot = NULL;
 
 	return slot;
 }
 
-static bool mapping_level_dirty_bitmap(struct kvm_vcpu *vcpu, gfn_t large_gfn)
-{
-	return !gfn_to_memslot_dirty_bitmap(vcpu, large_gfn, true);
-}
-
 static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn,
 			 bool *force_pt_level)
 {
 	int host_level, level, max_level;
+	struct kvm_memory_slot *slot;
+
+	slot = kvm_vcpu_gfn_to_memslot(vcpu, large_gfn);
 
 	if (likely(!*force_pt_level))
-		*force_pt_level = mapping_level_dirty_bitmap(vcpu, large_gfn);
+		*force_pt_level = !memslot_valid_for_gpte(slot, true);
 	if (unlikely(*force_pt_level))
 		return PT_PAGE_TABLE_LEVEL;