qdev: add function qdev_set_id()

In order to have an easy way to add a new qdev with a specific id
carve out the needed functionality from qdev_device_add() into a new
function qdev_set_id().

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>

include/monitor/qdev.h

@@ -12,5 +12,6 @@ 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, const char *id);
 
 #endif

qdev-monitor.c

@@ -539,10 +539,28 @@ static BusState *qbus_find(const char *path, Error **errp)
     return bus;
 }
 
+void qdev_set_id(DeviceState *dev, const char *id)
+{
+    if (id) {
+        dev->id = id;
+    }
+
+    if (dev->id) {
+        object_property_add_child(qdev_get_peripheral(), dev->id,
+                                  OBJECT(dev), 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), NULL);
+        g_free(name);
+    }
+}
+
 DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
 {
     DeviceClass *dc;
-    const char *driver, *path, *id;
+    const char *driver, *path;
     DeviceState *dev;
     BusState *bus = NULL;
     Error *err = NULL;
@@ -591,21 +609,7 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
         qdev_set_parent_bus(dev, bus);
     }
 
-    id = qemu_opts_id(opts);
-    if (id) {
-        dev->id = id;
-    }
-
-    if (dev->id) {
-        object_property_add_child(qdev_get_peripheral(), dev->id,
-                                  OBJECT(dev), 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), NULL);
-        g_free(name);
-    }
+    qdev_set_id(dev, qemu_opts_id(opts));
 
     /* set properties */
     if (qemu_opt_foreach(opts, set_property, dev, &err)) {