memory: convert memory_region_destroy to object_unparent

Explicitly call object_unparent in the few places where we
will re-create the memory region.  If the memory region is
simply being destroyed as part of device teardown, let QOM
handle it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/docs/memory.txt b/docs/memory.txt
index 5bdbdb3691..b12f1f049a 100644
--- a/docs/memory.txt
+++ b/docs/memory.txt
@@ -74,11 +74,16 @@ Region lifecycle
 ----------------
 
 A region is created by one of the constructor functions (memory_region_init*())
-and destroyed by the destructor (memory_region_destroy()).  In between,
-a region can be added to an address space by using memory_region_add_subregion()
-and removed using memory_region_del_subregion().  Region attributes may be
-changed at any point; they take effect once the region becomes exposed to the
-guest.
+and attached to an object.  It is then destroyed by object_unparent() or simply
+when the parent object dies.
+
+In between, a region can be added to an address space
+by using memory_region_add_subregion() and removed using
+memory_region_del_subregion().  Destroying the region implicitly
+removes the region from the address space.
+
+Region attributes may be changed at any point; they take effect once
+the region becomes exposed to the guest.
 
 Overlapping regions and priority
 --------------------------------