KVM: Remove memory alias support

As advertised in feature-removal-schedule.txt.  Equivalent support is provided
by overlapping memory regions.

Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 84a0906..65417e3 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -841,7 +841,7 @@
 }
 EXPORT_SYMBOL_GPL(kvm_is_error_hva);
 
-struct kvm_memory_slot *gfn_to_memslot_unaliased(struct kvm *kvm, gfn_t gfn)
+struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
 {
 	int i;
 	struct kvm_memslots *slots = kvm_memslots(kvm);
@@ -855,20 +855,13 @@
 	}
 	return NULL;
 }
-EXPORT_SYMBOL_GPL(gfn_to_memslot_unaliased);
-
-struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
-{
-	gfn = unalias_gfn(kvm, gfn);
-	return gfn_to_memslot_unaliased(kvm, gfn);
-}
+EXPORT_SYMBOL_GPL(gfn_to_memslot);
 
 int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
 {
 	int i;
 	struct kvm_memslots *slots = kvm_memslots(kvm);
 
-	gfn = unalias_gfn_instantiation(kvm, gfn);
 	for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
 		struct kvm_memory_slot *memslot = &slots->memslots[i];
 
@@ -913,7 +906,6 @@
 	struct kvm_memslots *slots = kvm_memslots(kvm);
 	struct kvm_memory_slot *memslot = NULL;
 
-	gfn = unalias_gfn(kvm, gfn);
 	for (i = 0; i < slots->nmemslots; ++i) {
 		memslot = &slots->memslots[i];
 
@@ -934,8 +926,7 @@
 {
 	struct kvm_memory_slot *slot;
 
-	gfn = unalias_gfn_instantiation(kvm, gfn);
-	slot = gfn_to_memslot_unaliased(kvm, gfn);
+	slot = gfn_to_memslot(kvm, gfn);
 	if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
 		return bad_hva();
 	return gfn_to_hva_memslot(slot, gfn);
@@ -1202,8 +1193,7 @@
 {
 	struct kvm_memory_slot *memslot;
 
-	gfn = unalias_gfn(kvm, gfn);
-	memslot = gfn_to_memslot_unaliased(kvm, gfn);
+	memslot = gfn_to_memslot(kvm, gfn);
 	if (memslot && memslot->dirty_bitmap) {
 		unsigned long rel_gfn = gfn - memslot->base_gfn;