On 2024/08/06 22:29, Michael S. Tsirkin wrote:
On Tue, Aug 06, 2024 at 04:35:44PM +0900, Akihiko Odaki wrote:
On 2024/08/05 19:08, Michael S. Tsirkin wrote:
On Mon, Aug 05, 2024 at 06:37:58PM +0900, Akihiko Odaki wrote:
If cross-migrate=off, QEMU can still migrate on the same host (checkpoint
and restart). QEMU can also migrate across hosts if the user ensures they
are on the same platform.
What is so special about checkpoint/restart? I guess we hope that
downgrades are uncommon, but they are possible...
Downgrades will not work with cross-migrate=off. Users who want downgrades
should use cross-migrate=on.
We also don't know that upgrades do not disable a feature:
can happen if e.g. there's a serious bug in the feature.
Basically, this makes the feature too fragile, in my opinion.
We can do nothing in such a case. Whether it is on a single host or
multiple hosts, we cannot support migration if features once enabled
disappear.
Regards,
Akihiko Odaki
