Re: [virtio] [PATCH RFC] Clarify FAILED status handling

[Cornelia Huck <cornelia.huck@de.ibm.com>]

On Wed, 30 Nov 2016 16:57:16 +0100
Jan Kiszka <jan.kiszka@siemens.com> wrote:

> On 2016-11-30 16:34, Cornelia Huck wrote:
> > We did not give any guidance before what the device is supposed to
> > do if the driver set the FAILED status bit. Instruct the device to
> > leave the driver alone and to ignore any driver actions other than
> > reset.
> > 
> > As we did not specify that before, formulate this as SHOULD so that
> > existing implementations stay compliant.
> > 
> > Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
> > ---
> > 
> > I noticed that we don't really say what the FAILED status bit
> > should effect (it's currently basically driver-only, and e.g.
> > qemu does not do anything with it). It is probably more useful
> > if it actually has consequences for device operation -- although
> > we certainly don't want to break existing implementations.
> 
> Is there a real use case in sight? The other option is to phase it out
> if it is practically without effect so far and we only speculate that it
> might be useful.

Not really. The only useful thing about FAILED today is that you can
notice that something went wrong if you see it e.g. in a dump (and even
then, it does not tell you much).

I'd not be opposed to phasing it out, either.