This is in preparation to extending config changed event handling
in core.
Wrapping these in an API also seems to make for a cleaner code.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>