KVM: cleanup memslot_id function

We can get memslot id from memslot->id directly
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

include/linux/kvm_host.h

@@ -365,7 +365,6 @@ pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
 		      bool *writable);
 pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
 			 struct kvm_memory_slot *slot, gfn_t gfn);
-int memslot_id(struct kvm *kvm, gfn_t gfn);
 void kvm_release_pfn_dirty(pfn_t);
 void kvm_release_pfn_clean(pfn_t pfn);
 void kvm_set_pfn_dirty(pfn_t pfn);
@@ -597,6 +596,11 @@ static inline void kvm_guest_exit(void)
 	current->flags &= ~PF_VCPU;
 }
 
+static inline int memslot_id(struct kvm *kvm, gfn_t gfn)
+{
+	return gfn_to_memslot(kvm, gfn)->id;
+}
+
 static inline unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,
 					       gfn_t gfn)
 {

virt/kvm/kvm_main.c

@@ -996,23 +996,6 @@ unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn)
 	return size;
 }
 
-int memslot_id(struct kvm *kvm, gfn_t gfn)
-{
-	int i;
-	struct kvm_memslots *slots = kvm_memslots(kvm);
-	struct kvm_memory_slot *memslot = NULL;
-
-	for (i = 0; i < slots->nmemslots; ++i) {
-		memslot = &slots->memslots[i];
-
-		if (gfn >= memslot->base_gfn
-		    && gfn < memslot->base_gfn + memslot->npages)
-			break;
-	}
-
-	return memslot - slots->memslots;
-}
-
 static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
 				     gfn_t *nr_pages)
 {