diff --git a/hw/xen/xen-legacy-backend.c b/hw/xen/xen-legacy-backend.c
index be3cf4a195..085fd31ef7 100644
--- a/hw/xen/xen-legacy-backend.c
+++ b/hw/xen/xen-legacy-backend.c
@@ -276,7 +276,8 @@ static struct XenLegacyDevice *xen_be_get_xendev(const char *type, int dom,
     xendev = g_malloc0(ops->size);
     object_initialize(&xendev->qdev, ops->size, TYPE_XENBACKEND);
     OBJECT(xendev)->free = g_free;
-    qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev));
+    qdev_set_id(DEVICE(xendev), g_strdup_printf("xen-%s-%d", type, dev),
+                &error_fatal);
     qdev_realize(DEVICE(xendev), xen_sysbus, &error_fatal);
     object_unref(OBJECT(xendev));
 
diff --git a/include/monitor/qdev.h b/include/monitor/qdev.h
index 389287eb44..74e6c55a2b 100644
--- a/include/monitor/qdev.h
+++ b/include/monitor/qdev.h
@@ -9,6 +9,29 @@ void qmp_device_add(QDict *qdict, QObject **ret_data, Error **errp);
 
 int qdev_device_help(QemuOpts *opts);
 DeviceState *qdev_device_add(QemuOpts *opts, Error **errp);
-void qdev_set_id(DeviceState *dev, char *id);
+
+/**
+ * qdev_set_id: parent the device and set its id if provided.
+ * @dev: device to handle
+ * @id: id to be given to the device, or NULL.
+ *
+ * Returns: the id of the device in case of success; otherwise NULL.
+ *
+ * @dev must be unrealized, unparented and must not have an id.
+ *
+ * If @id is non-NULL, this function tries to setup @dev qom path as
+ * "/peripheral/id". If @id is already taken, it fails. If it succeeds,
+ * the id field of @dev is set to @id (@dev now owns the given @id
+ * parameter).
+ *
+ * If @id is NULL, this function generates a unique name and setups @dev
+ * qom path as "/peripheral-anon/name". This name is not set as the id
+ * of @dev.
+ *
+ * Upon success, it returns the id/name (generated or provided). The
+ * returned string is owned by the corresponding child property and must
+ * not be freed by the caller.
+ */
+const char *qdev_set_id(DeviceState *dev, char *id, Error **errp);
 
 #endif
diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c
index b7c2d69207..0b6833cc57 100644
--- a/softmmu/qdev-monitor.c
+++ b/softmmu/qdev-monitor.c
@@ -593,22 +593,35 @@ static BusState *qbus_find(const char *path, Error **errp)
 }
 
 /* Takes ownership of @id, will be freed when deleting the device */
-void qdev_set_id(DeviceState *dev, char *id)
+const char *qdev_set_id(DeviceState *dev, char *id, Error **errp)
 {
-    if (id) {
-        dev->id = id;
-    }
+    ObjectProperty *prop;
 
-    if (dev->id) {
-        object_property_add_child(qdev_get_peripheral(), dev->id,
-                                  OBJECT(dev));
+    assert(!dev->id && !dev->realized);
+
+    /*
+     * object_property_[try_]add_child() below will assert the device
+     * has no parent
+     */
+    if (id) {
+        prop = object_property_try_add_child(qdev_get_peripheral(), id,
+                                             OBJECT(dev), NULL);
+        if (prop) {
+            dev->id = id;
+        } else {
+            g_free(id);
+            error_setg(errp, "Duplicate device ID '%s'", id);
+            return NULL;
+        }
     } else {
         static int anon_count;
         gchar *name = g_strdup_printf("device[%d]", anon_count++);
-        object_property_add_child(qdev_get_peripheral_anon(), name,
-                                  OBJECT(dev));
+        prop = object_property_add_child(qdev_get_peripheral_anon(), name,
+                                         OBJECT(dev));
         g_free(name);
     }
+
+    return prop->name;
 }
 
 DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
@@ -691,7 +704,13 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
         }
     }
 
-    qdev_set_id(dev, g_strdup(qemu_opts_id(opts)));
+    /*
+     * set dev's parent and register its id.
+     * If it fails it means the id is already taken.
+     */
+    if (!qdev_set_id(dev, g_strdup(qemu_opts_id(opts)), errp)) {
+        goto err_del_dev;
+    }
 
     /* set properties */
     if (qemu_opt_foreach(opts, set_property, dev, errp)) {