---
upgrade:
  - |
    The default QEMU machine type for ARMv7 architecture is now changed
    to ``virt`` (from the older ``vexpress-a15``, which is a particular
    ARM development board).  The ``virt`` board is the recommended
    default for ARMv7, which is explicitly designed to be
    used with virtual machines.  It is more flexible, supports PCI and
    'virtio' devices, has decent RAM limits, and so forth.  For
    pre-existing Nova guests on ARMv7 to acquire the ``virt`` machine
    type: (a) upgrade Nova with this fix; (b) explicitly start and stop
    the guests, then they will pick up the 'virt' machine type.