Re: [PATCH v5 0/5] Disable Deprecated Features by Default on s390 CPU Models

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(a)redhat.com&gt; Peter, Michal, could we still get this merged for libvirt 11.6 ? Thomas