On Thu, Mar 02, 2023 at 07:01:56PM -0500, Michael S. Tsirkin wrote:
> On Thu, Mar 02, 2023 at 03:19:12PM -0500, Stefan Hajnoczi wrote:
>
> On Thu, Mar 02, 2023 at 06:40:29PM +0000, Parav Pandit wrote:
> > >
> > >
>
From: Michael S. Tsirkin <>
> > >
> Sent: Thursday, March 2, 2023 8:05 AM
> > >
> > > > +When \field{status} is VIRTIO_ADMIN_STATUS_OK, \field{status_qialifier}
> > > > +is reserved and set to zero by the device.
> > > > +
> >
> s/status_qialifier/status_qualifier
> >
> Missed from v10 of Feb.
> > >
> > > > +When \field{status} is VIRTIO_ADMIN_STATUS_EINVAL, the following table
> > > > +describes possible \field{status_qialifier} values:
> >
> s/status_qialifier/status_qualifier
> > >
> >
> Can you please add other useful error codes in addition to the EINVAL?
> >
> Few that we are needed EAGAIN, ENOMEM, EBUSY, ENODEV.
> >
>
> Please define a unique constant for each error condition that can occur
>
> instead of sharing catch-all errno constants between multiple error
>
> conditions. If a driver wants to squash them together into an errno,
>
> that's fine, but I think doing this at the hardware interface level is
>
> just propagating the mistakes of errnos.
> >
>
> Only status_qualifier is needed and the vague status field can be
>
> dropped. It's not clear to me why adding EAGAIN, ENOMEM, EBUSY, and
>
> ENODEV is useful. They have no meaning to the driver, only the
>
> status_qualifier really indicates what is going on.
>
> At a high level at the moment we have only two cases:
> - ok
> - invalid input supplied by driver
>
> maybe we will have more reasons for a failure - remains to
> be seen.
>
>
>
>
>
> >
>
> I'm sure you guys have discussed this previously, but please provide
>
> rationale in the spec because it looks weird to someone with fresh eyes.
> >
>
> Stefan
>
> Really most drivers just want to propagate errno to userspace.
> All the detailed reporting is for sure well intentional but
> in the end it is at best printed into log - end to end
> people just end up with a switch statement
> converting these to errno codes.
> So we are passing them from device and this way there will be
> some uniformity.
Please clarify the rationale in the spec. I don't agree with it, as
explained in my earlier email, but as long as its documented, people can
try to follow it.
Stefan
