Re: multi-domain PCI and sysfs

Jon Smirl
2004-09-06T01:39:12Z

Another way to look at this would be to create one vga device per
domain. I could then hook the vga=0/1 attribute off from this device
and avoid the problem of creating domain nodes under /sys/devices

On Sun, 5 Sep 2004 17:06:50 -0700, Jesse Barnes <jbarnes@engr.sgi.com> wrote:
> On Sunday, September 5, 2004 4:04 pm, Matthew Wilcox wrote:
> > On Sat, Sep 04, 2004 at 04:03:56PM -0700, Jesse Barnes wrote:
> > > On Saturday, September 4, 2004 3:45 pm, Jon Smirl wrote:
> > > > Is this a multipath configuration where pci0000:01 and pci0000:02 can
> > > > both get to the same target bus? So both busses are top level busses?
> > > >
> > > > I'm trying to figure out where to stick the vga=0/1 attribute for
> > > > disabling all the VGA devices in a domain. It's starting to look like
> > > > there isn't a single node in sysfs that corresponds to a domain, in
> > > > this case there are two for the same domain.
> > >
> > > Yes, I think that's the case. Matthew would probably know for sure
> > > though.
> >
> > Huh, eh, what? There's no such thing as multipath PCI configurations.
> > The important concepts in PCI are:
>
> Right, but I was answering his question about whether or not there was a place
> to stick his 'vga' control file on a per-domain basis. There would be if the
> layout was something like this:
>
> /sys/devices/pciDDDD/BB/SS.F/foo
> rather than the current
> /sys/devices/pciDDDD:BB/DDDD:BB:SS.F/foo
>
> > I haven't really looked at the VGA attribute. I think Ivan or Grant
> > would be better equipped to help you on this front. I remember them
> > rehashing it 2-3 years ago.
>
> I'm actually ok with a system wide vga arbitration driver, assuming that we'll
> never have to worry about the scalability of stuff that wants to do legacy
> vga I/O.
>
> Thanks,
> Jesse
>
>

--
Jon Smirl
jonsmirl@gmail.com