Re: [PATCH] pci: More PRI/PASID cleanup

Alex Williamson
2011-11-08T18:20:11Z

On Tue, 2011-11-08 at 18:54 +0100, Roedel, Joerg wrote:
> On Tue, Nov 08, 2011 at 10:31:58AM -0700, Alex Williamson wrote:
> > On Tue, 2011-11-08 at 18:17 +0100, Roedel, Joerg wrote:
> > > On Tue, Nov 08, 2011 at 09:44:30AM -0700, Alex Williamson wrote:
> > >
> > > > bit 0 (PCI_PASID_ENABLE) is reserved in the CAP register...
> > >
> > > Is it? Which spec are you using? In my version it is not reserved but
> > > states if it is supported to set the enable-bit.
> >
> > Latest I can find is the March 31, 2011 PASID ECN, which just lists that
> > bit as reserved.
>
> Okay, my one is older and there it is stated as I implemented it. I will
> check with reality first before changing the code...

My guess is that someone asked why a device would ever expose this table
if it didn't support enable as a capability. So, I wouldn't be
surprised if your hardware sets it, but it's probably just as safe to
assume enable is supported if the PASID table exists. Thanks,

Alex

> > I can drop it if need be, was just trying to do some cleanup on the
> > consistency of pci_reg.h before adding a bunch more defines to help
> > bounds checking and parsing for vfio-pci. Unless my spec is outdated,
> > it seems like there's more than an aesthetic change here though, so
> > resolving the conflicts with your latest work might be warranted.
>
> Fine with me. The best is probably when I carry this change forward
> (when Jesse is ok with that) and put my changes on-top of that.
>
> Thanks,
>
> Joerg
>