---
docs/devel/migration.rst | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/docs/devel/migration.rst b/docs/devel/migration.rst
index c3e1400c0c..bfd8710c95 100644
--- a/docs/devel/migration.rst
+++ b/docs/devel/migration.rst
@@ -165,13 +165,17 @@ An example (from hw/input/pckbd.c)
}
};
-We are declaring the state with name "pckbd".
-The ``version_id`` is 3, and the fields are 4 uint8_t in a KBDState structure.
-We registered this with:
+We are declaring the state with name "pckbd". The ``version_id`` is
+3, and there are 4 uint8_t fields in the KBDState structure. We
+registered this ``VMSTATEDescription`` with one of the following
+functions. The first one will generate a device ``instance_id``
+different for each registration. Use the second one if you already
+have an id that is different for each instance of the device:
.. code:: c
- vmstate_register(NULL, 0, &vmstate_kbd, s);
+ vmstate_register_any(NULL, &vmstate_kbd, s);
+ vmstate_register(NULL, instance_id, &vmstate_kbd, s);
For devices that are ``qdev`` based, we can register the device in the class
init function: