+ /*
+ * Make a full copy of the old memslot, the pointer will become stale
+ * when the memslots are re-sorted by update_memslots(), and the old
+ * memslot needs to be referenced after calling update_memslots(), e.g.
+ * to free its resources and for arch specific behavior. This needs to
+ * happen *after* (re)acquiring slots_arch_lock.
+ */
+ slot = id_to_memslot(slots, new->id);
+ if (slot) {
+ old = *slot;
+ } else {
+ WARN_ON_ONCE(change != KVM_MR_CREATE);
+ memset(&old, 0, sizeof(old));
+ old.id = new->id;
+ old.as_id = as_id;
+ }
+
+ /* Copy the arch-specific data, again after (re)acquiring slots_arch_lock. */
+ memcpy(&new->arch, &old.arch, sizeof(old.arch));
+