Re: multi-domain PCI and sysfs

[Jesse Barnes <jbarnes@engr.sgi.com>]

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