KVM: Rename lru_slot to last_used_slot

lru_slot is used to keep track of the index of the most-recently used
memslot. The correct acronym would be "mru" but that is not a common
acronym. So call it last_used_slot which is a bit more obvious.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Message-Id: <20210804222844.1419481-2-dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/s390/kvm/kvm-s390.c

@@ -1953,7 +1953,7 @@ out:
 static int gfn_to_memslot_approx(struct kvm_memslots *slots, gfn_t gfn)
 {
 	int start = 0, end = slots->used_slots;
-	int slot = atomic_read(&slots->lru_slot);
+	int slot = atomic_read(&slots->last_used_slot);
 	struct kvm_memory_slot *memslots = slots->memslots;
 
 	if (gfn >= memslots[slot].base_gfn &&
@@ -1974,7 +1974,7 @@ static int gfn_to_memslot_approx(struct kvm_memslots *slots, gfn_t gfn)
 
 	if (gfn >= memslots[start].base_gfn &&
 	    gfn < memslots[start].base_gfn + memslots[start].npages) {
-		atomic_set(&slots->lru_slot, start);
+		atomic_set(&slots->last_used_slot, start);
 	}
 
 	return start;

include/linux/kvm_host.h

@@ -522,7 +522,7 @@ struct kvm_memslots {
 	u64 generation;
 	/* The mapping table from slot id to the index in memslots[]. */
 	short id_to_index[KVM_MEM_SLOTS_NUM];
-	atomic_t lru_slot;
+	atomic_t last_used_slot;
 	int used_slots;
 	struct kvm_memory_slot memslots[];
 };
@@ -1200,7 +1200,7 @@ static inline struct kvm_memory_slot *
 search_memslots(struct kvm_memslots *slots, gfn_t gfn)
 {
 	int start = 0, end = slots->used_slots;
-	int slot = atomic_read(&slots->lru_slot);
+	int slot = atomic_read(&slots->last_used_slot);
 	struct kvm_memory_slot *memslots = slots->memslots;
 
 	if (unlikely(!slots->used_slots))
@@ -1221,7 +1221,7 @@ search_memslots(struct kvm_memslots *slots, gfn_t gfn)
 
 	if (start < slots->used_slots && gfn >= memslots[start].base_gfn &&
 	    gfn < memslots[start].base_gfn + memslots[start].npages) {
-		atomic_set(&slots->lru_slot, start);
+		atomic_set(&slots->last_used_slot, start);
 		return &memslots[start];
 	}
 

virt/kvm/kvm_main.c

@@ -1224,8 +1224,8 @@ static inline void kvm_memslot_delete(struct kvm_memslots *slots,
 
 	slots->used_slots--;
 
-	if (atomic_read(&slots->lru_slot) >= slots->used_slots)
+	if (atomic_read(&slots->last_used_slot) >= slots->used_slots)
-		atomic_set(&slots->lru_slot, 0);
+		atomic_set(&slots->last_used_slot, 0);
 
 	for (i = slots->id_to_index[memslot->id]; i < slots->used_slots; i++) {
 		mslots[i] = mslots[i + 1];