Comment 13 for bug 1821798

Reviewed: https://review.opendev.org/666152
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=2009859b5225541d8560e5ca1efb91de644d12be
Submitter: Zuul
Branch: stable/queens

commit 2009859b5225541d8560e5ca1efb91de644d12be
Author: Francois Palin <email address hidden>
Date: Tue Mar 26 15:22:40 2019 -0400

    Include all network devices in nova diagnostics

    get_instance_diagnostics expected all interfaces
    to have a <target> element with a "dev" attribute in
    the instance XML. This is not the case for VFIO
    interfaces (<interface type="hostdev">).
    This caused an IndexError when looping over
    the interfaces.

    This patch fixes this issue by retrieving interfaces
    data directly from the guest XML and adding nics
    appropriately to the diagnostics object.

    The new functional test has been left out of this
    cherry-pick, since a lot of the test code that
    supports the test is missing and would have to be
    back-ported just for that one test, including a
    ramification of other commit dependencies.
    The functional code change itself is rather simple,
    and not having this functional test present in
    Queens is considered to be low risk.

    Change-Id: I8ef852d449e9e637d45e4ac92ffc5d1abd8d31c5
    Closes-Bug: #1821798
    (cherry picked from commit ab7c968b6f66404c032f62a952e353f94d3be165)
    (cherry picked from commit 1d4f64b190afc60b0c2a56de718209869c41cfb3)
    (cherry picked from commit 19ca8bcc2232e1d81efc349948a21cc1c3fc811d)