Re: [virtio-comment] RE: [PATCH v13] virtio-net: support the virtqueue coalescing moderation

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Mar 22, 2023 at 04:49:58PM +0000, Parav Pandit wrote:
> 
> > From: Michael S. Tsirkin <mst@redhat.com>
> > Sent: Wednesday, March 22, 2023 12:47 PM
> > 
> > I agree with Cornelia here. Yes if devices do not want to trust drivers then they
> > will validate input but what exactly happens then is currently up to device.
> > If we want to try and specify devices in all cases of out of spec input that's a big
> > project, certainly doable but I would rather not connect it to this, rather
> > boutique, feature.
> Both of your and Cornelia's comment is abstract to me.
> We cannot change past.

But we can make sure things are consistent. Currently we don't describe
device behaviour if driver is out of spec and I see 0 reasons to start
doing it with coalescing commands specifically.

> For the new command of interest here, hen driver supplied incorrect values, the device will return error.

It might be easier for device to just set NEEDS_RESET and stop
responding. For a hypervisor implementation that's often better than returning error
since device state is then preserved making things easier to debug.

> How to implement is upto the device to figure out.


what to do is also up to the device.

-- 
MST