Re: [PATCH v2 4/4] virtio-net: Add support for USO features
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.
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MST