kvm: commonize allocation of the new memory slots

commit f2a81036516e2b97c07c49dd6d51d36bfa43593d upstream.

The two kmemdup invocations can be unified.  I find that the new
placement of the comment makes it easier to see what happens.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index feffb3f7c3939059a542e630772e0790760fb378..cf0c0778620495ceea86110072ffa193c4c25905 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -841,11 +841,12 @@ int __kvm_set_memory_region(struct kvm *kvm,
                        goto out_free;
        }
 
+       slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
+                       GFP_KERNEL);
+       if (!slots)
+               goto out_free;
+
        if ((change == KVM_MR_DELETE) || (change == KVM_MR_MOVE)) {
-               slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
-                               GFP_KERNEL);
-               if (!slots)
-                       goto out_free;
                slot = id_to_memslot(slots, mem->slot);
                slot->flags |= KVM_MEMSLOT_INVALID;
 
@@ -861,6 +862,12 @@ int __kvm_set_memory_region(struct kvm *kvm,
                 *      - kvm_is_visible_gfn (mmu_check_roots)
                 */
                kvm_arch_flush_shadow_memslot(kvm, slot);
+
+               /*
+                * We can re-use the old_memslots from above, the only difference
+                * from the currently installed memslots is the invalid flag.  This
+                * will get overwritten by update_memslots anyway.
+                */
                slots = old_memslots;
        }
 
@@ -868,19 +875,6 @@ int __kvm_set_memory_region(struct kvm *kvm,
        if (r)
                goto out_slots;
 
-       r = -ENOMEM;
-       /*
-        * We can re-use the old_memslots from above, the only difference
-        * from the currently installed memslots is the invalid flag.  This
-        * will get overwritten by update_memslots anyway.
-        */
-       if (!slots) {
-               slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
-                               GFP_KERNEL);
-               if (!slots)
-                       goto out_free;
-       }
-
        /*
         * IOMMU mapping:  New slots need to be mapped.  Old slots need to be
         * un-mapped and re-mapped if their base changes.  Since base change