modules: add module_obj() note to QOM docs

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jose R. Ziviani <jziviani@suse.de>
Message-Id: <20210624103836.2382472-23-kraxel@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/docs/devel/qom.rst b/docs/devel/qom.rst
index 42d0dc4f4da801e6c8f73a634bf15a88bf090f3e..e5fe3597cd823394392e065b6628b3aeb6ec9b8b 100644 (file)
--- a/docs/devel/qom.rst
+++ b/docs/devel/qom.rst
@@ -87,6 +87,14 @@ specific type:
    #define MY_DEVICE(obj) \
       OBJECT_CHECK(MyDevice, obj, TYPE_MY_DEVICE)
 
+In case the ObjectClass implementation can be built as module a
+module_obj() line must be added to make sure qemu loads the module
+when the object is needed.
+
+.. code-block:: c
+
+   module_obj(TYPE_MY_DEVICE);
+
 Class Initialization
 ====================