Comment 20 for bug 1362929

Reviewed: https://review.openstack.org/123811
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=867bdedf81533f283aae4de4488d54c254bb7f07
Submitter: Jenkins
Branch: master

commit 867bdedf81533f283aae4de4488d54c254bb7f07
Author: Matt Riedemann <email address hidden>
Date: Wed Sep 24 11:21:59 2014 -0700

    Fallback to legacy live migration if config error

    Commit ea7da5152cdca7ba674e2137c3899909995e2287 added a path to using
    migrateToURI2 for live migration if the version of libvirt used has the
    VIR_DOMAIN_XML_MIGRATABLE flag set.

    However, a bug in older versions of libvirt causes the live migration to
    fail because it's incorrectly validating the old and new domain xml's
    for ABI stability.

    Not all distros are running with the patched version of libvirt so add a
    check in place such that if we fail live migration on the new path with
    VIR_ERR_CONFIG_UNSUPPORTED, assume it's due to this issue and attempt
    the legacy migrateToURI call.

    Closes-Bug: #1362929
    Related-Bug: #1279563

    Change-Id: Ie82566121c2ed3a6d55919bc111358f4129cb404