Re: [PATCH] s390/cio: add missing MODULE_DESCRIPTION() macros

Eric Farman
2024-06-19T14:00:26Z

On Wed, 2024-06-19 at 12:32 +0200, Halil Pasic wrote:
> On Tue, 18 Jun 2024 16:11:33 -0400
> Eric Farman <farman@linux.ibm.com> wrote:
>
> > > > +MODULE_DESCRIPTION("VFIO based Physical Subchannel device
> > > > driver");
> > >
> > > Halil/Mathew/Eric,
> > > Could you please comment on this ?
> >
> > That's what is in the prologue, and is fine.
>
> Eric can you explain it to me why is the attribute "physical"
> appropriate
> here? I did a quick grep for "Physical Subchannel" only turned up
> hits
> in vfio-ccw.

One hit, in the prologue comment of this module. "Physical device" adds
three to the tally, but only one of those is in vfio-ccw so we should
expand your query regarding "physical" vs "emulated" vs "virtual" in
the context of, say, tape devices.

>
> My best guess is that "physical" was somehow intended to mean the
> opposite of "virtual". But actually it does not matter if our
> underlying
> subchannel is emulated or not, at least AFAIU.

I also believe this was intended to mean "not virtual," regardless of
whether there's emulation taking place underneath. That point is moot
since I don't see that information being surfaced, such that the driver
can only work with "physical" subchannels.

I'm fine with removing it if it bothers you, but I don't see it as an
issue.

Thanks,
Eric

>
> Regards,
> Halil