---
issues:
  - |
    `bug 1894804`_ documents a known device detachment issue with QEMU
    ``4.2.0`` as shipped by the Focal ``20.04`` Ubuntu release. This can lead
    to the failure to detach devices from the underlying libvirt domain of an
    instance as QEMU never emits the correct ``DEVICE_DELETED`` event to
    libvirt. This in turn leaves the device attached within libvirt and
    OpenStack Nova while it has been detached from the underlying QEMU process.
    Subsequent attempts to detach the device will also fail as it is no longer
    found within the QEMU process.

    There is no known workaround within OpenStack Nova to this issue.

    .. _bug 1894804: https://bugs.launchpad.net/qemu/+bug/1894804