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

[Jason Wang]

On Fri, Jul 26, 2024 at 2:08 PM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Thu, Jul 25, 2024 at 06:18:20PM -0400, Peter Xu wrote:
> > On Tue, Aug 01, 2023 at 01:31:48AM +0300, Yuri Benditovich wrote:
> > > USO features of virtio-net device depend on kernel ability
> > > to support them, for backward compatibility by default the
> > > features are disabled on 8.0 and earlier.
> > >
> > > Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
> > > Signed-off-by: Andrew Melnychecnko <andrew@daynix.com>
> >
> > Looks like this patch broke migration when the VM starts on a host that has
> > USO supported, to another host that doesn't..
>
> This was always the case with all offloads. The answer at the moment is,
> don't do this.

Sometimes, it's not easy for management to know this.

For example, in the past we suffered from the removal of UFO ....

> Long term, we need to start exposing management APIs
> to discover this, and management has to disable unsupported features.
>
> --
> MST
>

Thanks