I read code in test-qdev-global-props.c. The test function test_static_globalprop_subprocess is:

static void test_static_globalprop_subprocess(void)
{
    MyType *mt;
    static GlobalProperty props[] = {
        { TYPE_STATIC_PROPS, "prop1", "200" },
        {}
    };

    qdev_prop_register_global_list(props);

    mt = STATIC_TYPE(object_new(TYPE_STATIC_PROPS));
    qdev_init_nofail(DEVICE(mt));

    g_assert_cmpuint(mt->prop1, ==, 200);
    g_assert_cmpuint(mt->prop2, ==, PROP_DEFAULT);
}

I found that the GlobalProperty props are registered, but I can not find where it be used. Can someone explain it? Thanks!