Comment 0 for bug 1843883

In libvirt we can add some extra parameters into migration target uri in query parameter format.[1]
 [1] https://libvirt.org/remote.html
This is still vlaid for some usecases. For example in TripleO we define a path for key file to authenticate to the remote node by keyfile parameter.

However, since live_migration_uri was deprecated and replaced by live_migration_scheme, there are no available methods to configure this without using the deprecated parameter live_migration_uri.
We need some additional option like live_migration_extraparams which can be used to these define parameters, Otherwise it can break existing deployment which requires extra parameters configured.