---
upgrade:
  - |
    Added a new ``unique`` choice to the ``[libvirt]/sysinfo_serial``
    configuration which if set will result in the guest serial number being
    set to ``instance.uuid``. This is now the default value
    of the ``[libvirt]/sysinfo_serial`` config option and is the recommended
    choice since it ensures the guest serial is the same even if the instance
    is migrated between hosts.
