[Qemu-devel] [PATCH v4 11/33] pc-dimm: do not allow to set already used memdev

[Igor Mammedov <imammedo@redhat.com>]

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 <imammedo@redhat.com>
Acked-by: Peter Crosthwaite <peter.crostwaite@xilinx.com>
---
 hw/mem/pc-dimm.c |   17 ++++++++++++++++-
 1 files changed, 16 insertions(+), 1 deletions(-)

diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index b4937fe..3cced63 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -43,6 +43,21 @@ static void pc_dimm_get_size(Object *obj, Visitor *v, void *opaque,
     visit_type_int(v, &value, name, errp);
 }
 
+static void pc_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 pc_dimm_init(Object *obj)
 {
     PCDIMMDevice *dimm = PC_DIMM(obj);
@@ -51,7 +66,7 @@ static void pc_dimm_init(Object *obj)
                         NULL, NULL, NULL, &error_abort);
     object_property_add_link(obj, PC_DIMM_MEMDEV_PROP, TYPE_MEMORY_BACKEND,
                              (Object **)&dimm->hostmem,
-                             qdev_prop_allow_set_link_before_realize,
+                             pc_dimm_check_memdev_is_busy,
                              OBJ_PROP_LINK_UNREF_ON_RELEASE,
                              &error_abort);
 }
-- 
1.7.1