This change adds a second update command to the libvirt group
within nova-manage. This command will set or update the machine type of
the instance when the following criteria are met:
* The instance must have a ``vm_state`` of ``STOPPED``, ``SHELVED`` or
``SHELVED_OFFLOADED``.
* The machine type is supported. The supported list includes alias and
versioned types of ``pc``, ``pc-i440fx``, ``pc-q35``, ``q35``, ``virt``
or ``s390-ccw-virtio``.
* The update will not move the instance between underlying machine types.
For example, ``pc`` to ``q35``.
* The update will not move the instance between an alias and versioned
machine type or vice versa. For example, ``pc`` to ``pc-1.2.3`` or
``pc-1.2.3`` to ``pc``.
A --force flag is provided to skip the above checks but caution
should be taken as this could easily lead to the underlying ABI of the
instance changing when moving between machine types.
blueprint: libvirt-default-machine-type
Change-Id: I6b80021a2f90d3379c821dc8f02a72f350169eb3
c70cde057d