I posted patches for vdsm new NBD APIs:

For the big picture, see the feature page:

Changes:
- Adding option to run a service as user:group
- Adding back support for systemd-run and systemctl_stop to supervdsm.
- Introducing the NBD APIs
- Starting nbd module tests
- Allow running tests that need supervdsm on your laptop

The infrastructure changes may be useful for other maintainers.

Please review,
Nir