On 7/25/25 09:53, Jiri Denemark via Devel wrote:
> On Thu, Jul 24, 2025 at 14:39:02 -0400, Collin Walling wrote:
>> On 7/24/25 03:35, Thomas Huth via Devel wrote:
>>> On 30/06/2025 05.19, Collin Walling wrote:
>>>> Changelog
>>>>
>>>> v5
>>>> - dropped the "none" test in qemuxmlactivetest (see commit for
>>>> details)
>>>> - reordered patches to introduce some tests first, then add
>>>> qemu.conf changes
>>>>
>>>> v4
>>>> - added qemu.conf option to dictate the default behavior for the
>>>> deprecated_features attribute (Boris)
>>>> - added qemuxmlactivetests (Boris)
>>>> - snuck in missing documentation for deprecated_features in
>>>> formatdomain.rst
>>>>
>>>> v3
>>>> - added qemu caps check to avoid breaking s390 guests trying to
>>>> default deprecated_features='off' on QEMU versions that
>>>> do not support reporting these features
>>>>
>>>> v2
>>>> - changed behavior from disabling features on the host model to
>>>> instead flagging the guest CPU to disable deprecated features
>>>> - removed disabling deprecated features on host model in
>>>> virQEMUCapsInitCPUModelS390
>>>> - added flagging deprecated_feats in qemuProcessUpdateGuestCPU
>>>> - added tests for deprecated_features='on'
>>>> - split virQEMUCapsUpdateCPUDeprecatedFeatures update and
>>>> qemuProcessUpdateGuestCPU changes
>>>>
>>>> The intention of reporting deprecated features and modifying the guest
>>>> CPU model was to alleviate the user from the burden of preparing a guest
>>>> with the necessary amendments to assure migration to newer hardware.
>>>> While that goal was met by way of the "deprecated_features='on|off'"
>>>> attribute, it still adds an extra step that the user must be aware to
>>>> prepare a guest for migration and the errors that stem from an
>>>> unsuccessful migration (due to feature incompatibility) is not always
>>>> clear how to resolve.
>>>>
>>>> These patches make s390 CPU *host models* migration ready from the get-go
>>>> by introducing a qemu.conf option for disabling deprecated features by
>>>> default. They may still be disabled for other model types via the
>>>> respective attribute, or reenabled if desired. The configured behavior
>>>> may be overridden by explicitly providing the attribute within the
>>>> guest XML.
>>>
>>> The patch series sounds reasonable to me, so FWIW:
>>>
>>> Series
>>> Acked-by: Thomas Huth <thuth@redhat.com>
>>>
>>> Peter, Michal, could we still get this merged for libvirt 11.6 ?
>>>
>>> Thomas
>>
>> Thanks for the Ack and helping to move this along.
>>
>> I've posted a patch to the list for NEWS mentioning this features in
>> case this series is accepted in time for 11.6.
>
> Both this series and the NEWS patch are pushed now.
>
> Jirka
Thanks!
--
Regards,
Collin