[libvirt] question about job handling across migration protocol phases

While investigating a bug [1] found by Xen's osstest I realized I don't quite understand how to handle modify jobs (e.g. BeginJob/EndJob) on virDomainObj across the various phases of V3 migration protocol. E.g. on the src host the Begin, Perform, and Confirm phases are performed. Should a modify job start (BeginJob) in the Begin phase and stop (EndJob) in the Confirm phase? Or should each phase, if necessary, do BeginJob/EndJob? Same question for dst host. IMO the job should be held across the phases on each host, preventing any modifications during the overall migration process. Although I do worry about orphaned jobs, e.g. a missed EndJob caused by some obscure error in the migration machinery. Regards, Jim [1] https://lists.xenproject.org/archives/html/xen-devel/2018-08/msg01945.html