add optional 2nd stage initialization to -object/object-add commands

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>

1 files changed, 1 insertions, 0 deletions

diff --git a/qom/Makefile.objs b/qom/Makefile.objs
index 6a93ac7398..985003bd03 100644
--- a/qom/Makefile.objs
+++ b/qom/Makefile.objs
@@ -1,2 +1,3 @@
 common-obj-y = object.o container.o qom-qobject.o
 common-obj-y += cpu.o
+common-obj-y += object_interfaces.o