[Qemu-devel] [PATCH 12/35] dimm: do not allow to set already busy memdev

[Igor Mammedov]

using the same memdev backend more than once will cause
assersion at MemoryRegion mapping time becase it's already
mapped. Prevent it by checking that associated MemoryRegion
is not mapped.

Signed-off-by: Igor Mammedov <address@hidden>
---
 hw/mem/dimm.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/hw/mem/dimm.c b/hw/mem/dimm.c
index 76f2a11..65d4cd0 100644
--- a/hw/mem/dimm.c
+++ b/hw/mem/dimm.c
@@ -42,6 +42,21 @@ static void dimm_get_size(Object *obj, Visitor *v, void 
*opaque,
     visit_type_int(v, &value, name, errp);
 }
 
+static void dimm_check_memdev_is_busy(Object *obj, const char *name,
+                                      Object *val, Error **errp)
+{
+    MemoryRegion *mr;
+
+    mr = host_memory_backend_get_memory(MEMORY_BACKEND(val), errp);
+    if (memory_region_is_mapped(mr)) {
+        char *path = object_get_canonical_path_component(val);
+        error_setg(errp, "can't use already busy memdev: %s", path);
+        g_free(path);
+    } else {
+        qdev_prop_allow_set_link_before_realize(obj, name, val, errp);
+    }
+}
+
 static void dimm_initfn(Object *obj)
 {
     DimmDevice *dimm = DIMM(obj);
@@ -50,7 +65,7 @@ static void dimm_initfn(Object *obj)
                         NULL, NULL, NULL, &error_abort);
     object_property_add_link(obj, "memdev", TYPE_MEMORY_BACKEND,
                              (Object **)&dimm->hostmem,
-                             qdev_prop_allow_set_link_before_realize,
+                             dimm_check_memdev_is_busy,
                              OBJ_PROP_LINK_UNREF_ON_RELEASE,
                              &error_abort);
 }
-- 
1.9.0