Comment 16 for bug 1847361

If "restricting features after upgrade" is not an option until we came up upstream with a preferred approach to fix this the workarounds are:
- migrate away and back for upgrades (general practice, but sometimes impossible e.g. due to passthrough)
- the .so by using the functionality before upgrade (e.g. attach and detach a rbd device).
  I guess there could even be a valid config but invalid target which would achieve the same
  without the guest noticing.