---
features:
  - |
    In this release SR-IOV live migration support is added to the libvirt
    virt driver for Neutron interfaces. Neutron SR-IOV interfaces can be
    grouped into two categories, direct mode interfaces and indirect.
    Direct mode SR-IOV interfaces are directly attached to the guest and
    exposed to the guest OS. Indirect mode SR-IOV interfaces have a software
    interface such as a macvtap between the guest and the SR-IOV device.
    This feature enables transparent live migration for instances with
    indirect mode SR-IOV devices. As there is no generic way to copy
    hardware state during a live migration, direct mode migration is not
    transparent to the guest. For direct mode interfaces, we mimic the
    workflow already in place for suspend and resume. For instance with
    SR-IOV devices, we detach the direct mode interfaces before migration
    and re-attach them after the migration. As a result, instances
    with direct mode SR-IOV port will lose network connectivity during a
    migration unless a bond with a live migratable interface is created
    within the guest.
upgrade:
  - |
    The Libvirt SR-IOV migration feature intoduced in this release requires
    both the source and destination node to support the feature. As a result
    it will be automatically disabled until the conductor and compute nodes
    have been upgraded.