Re: [PATCH v10 03/10] admin: introduce group administration commands

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

On Wed, Mar 08, 2023 at 03:43:14PM +0100, Cornelia Huck wrote:
> On Wed, Mar 08 2023, Max Gurtovoy <mgurtovoy@nvidia.com> wrote:
> 
> > On 08/03/2023 14:07, Michael S. Tsirkin wrote:
> >> On Wed, Mar 08, 2023 at 12:55:37PM +0200, Max Gurtovoy wrote:
> >>>>> 5. VIRTIO_ADMIN_STATUS_COMMAND_SPECIFIC_ERR (for more info read the
> >>>>> command_specific_error field).
> >>>>
> >>>> I don't think it's a good idea, we'll have to agree to disagree.
> >>>
> >>> Ok.
> >>> can you explain why isn't this a good idea please ?
> >> 
> >> Pointless complexity for spec, devices and drivers. In the end drivers
> >> don't really do anything with all this detailed info.
> >> 
> >
> > Pointless according to your own opinion. As I mentioned, other 
> > specifications and devices work this way. I didn't invent it.
> >
> > All drivers in SW world ? All drivers in Linux ? or Virtio drivers ?
> 
> FWIW, I've spent enough time translating
> detailed-but-not-really-that-useful error status codes to -EINVAL for
> s390-specific things...
> 
> The only thing that might make sense to transmit to a consumer would be
> the difference between "this thing won't work" and "this thing might
> work if you retry later" (if the consumer is even in a place to retry.)

One place where that extra detail might be helpful is device debugging.
But there an error code out of list is too restrictive anyway, you want
"Turbo Encabulator 42 logarithmic casing failure".  I am still looking
for something that drivers are not likely to abuse. Maybe an ASCII
string?

-- 
MST