From: Lin Ma <lma@suse.com>
Date: Mon, 30 Mar 2015 08:36:29 +0000 (+0800)
Subject: hostmem: Prevent removing an in-use memory backend
X-Git-Tag: qemu-xen-4.7.0-rc1~369^2~3
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=36bce5ca5da7a7dbdc5001dc65b40b7439472106;p=qemu-xen.git

hostmem: Prevent removing an in-use memory backend

showing a memory device whose memdev is removed leads an assert:

(qemu) object_add memory-backend-ram,id=ram0,size=128M
(qemu) device_add pc-dimm,id=d0,memdev=ram0
(qemu) object_del ram0
(qemu) info memory-devices
**
ERROR:qom/object.c:1274:object_get_canonical_path_component:\
                            assertion failed: (obj->parent != NULL)
Aborted

The patch prevents removing an in-use mem backend and error out.

Signed-off-by: Lin Ma <lma@suse.com>
Message-Id: <1427704589-7688-3-git-send-email-lma@suse.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/backends/hostmem.c b/backends/hostmem.c
index 99e8f99da8..b7b6cf8f4a 100644
--- a/backends/hostmem.c
+++ b/backends/hostmem.c
@@ -335,12 +335,26 @@ host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
     }
 }
 
+static bool
+host_memory_backend_can_be_deleted(UserCreatable *uc, Error **errp)
+{
+    MemoryRegion *mr;
+
+    mr = host_memory_backend_get_memory(MEMORY_BACKEND(uc), errp);
+    if (memory_region_is_mapped(mr)) {
+        return false;
+    } else {
+        return true;
+    }
+}
+
 static void
 host_memory_backend_class_init(ObjectClass *oc, void *data)
 {
     UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
 
     ucc->complete = host_memory_backend_memory_complete;
+    ucc->can_be_deleted = host_memory_backend_can_be_deleted;
 }
 
 static const TypeInfo host_memory_backend_info = {