Re: [PATCH v5] virtio-net: clarify coalescing parameters settings

Michael S. Tsirkin
2024-06-13T06:13:58Z

On Tue, Jun 11, 2024 at 05:43:18PM +0000, Parav Pandit wrote:
>
>
> > From: Michael S. Tsirkin <mst@redhat.com>
> > Sent: Tuesday, June 11, 2024 10:00 PM
>
>
> > How we can we make progress with
> > the realease but sure we don't make backwards compat a pain?
> >
> > Ideas?
> >
> There is no functional break with this relaxation.
> Device set some non-zero defaults and driver didn't modify them....
> Anything broken? Unlikely.
> And device/driver has better performance, is that a problem? Unlikely.
>

Yes, it is possible. Driver can cache values it sets
and never query device with get.
Before anything is set, driver will report incorrect values.
What will break as a result? Hard to predict.

Given the patch is big, I am inclined to say it just should use
a feature bit.

--
MST