Introduces USER_CREATABLE interface that must be implemented by
objects which are designed to created with -object CLI option or
object-add QMP command.
Interface provides an ability to do an optional second stage
initialization of the object created with -object/object-add
commands. By providing complete() callback, which is called
after the object properties were set.
It allows to:
* prevents misusing of -object/object-add by filtering out
objects that are not designed for it.
* generalize second stage backend initialization instead of
adding custom APIs to perform it
* early error detection of backend initialization at -object/
object-add time rather than through a proxy DEVICE object
that tries to use backend.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>