---
upgrade:
  - |
    Live migration of instances with NUMA topologies is now disabled by default
    when using the libvirt driver. This includes live migration of instances
    with CPU pinning or hugepages. CPU pinning and huge page information for
    such instances is not currently re-calculated, as noted in `bug #1289064`_.
    This means that if instances were already present on the destination host,
    the migrated instance could be placed on the same dedicated cores as these
    instances or use hugepages allocated for another instance. Alternately, if
    the host platforms were not homogeneous, the instance could be assigned to
    non-existent cores or be inadvertently split across host NUMA nodes.

    The `long term solution`_ to these issues is to recalculate the XML on the
    destination node. When this work is completed, the restriction on live
    migration with NUMA topologies will be lifted.

    For operators that are aware of the issues and are able to manually work
    around them, the ``[workarounds] enable_numa_live_migration`` option can
    be used to allow the broken behavior.

    For more information, refer to `bug #1289064`_.

    .. _bug #1289064: https://bugs.launchpad.net/nova/+bug/1289064
    .. _long term solution: https://blueprints.launchpad.net/nova/+spec/numa-aware-live-migration
