Re: [Qemu-devel] [PATCH] pci: fixes to allow booting from extra root pci buses.

[Marcel Apfelbaum]

On 06/11/2015 03:45 PM, Michael S. Tsirkin wrote:
> On Thu, Jun 11, 2015 at 03:41:35PM +0300, Marcel Apfelbaum wrote:
> > The PXB device exposes a new pci root bridge with the
> > fw path:  /address@hidden/..., in which 4 is the root bus number.
> > Before this patch the fw path was wrongly computed:
> >      /address@hidden/address@hidden/...
> > Fix the above issues: Correct the bus number and remove the
> > extra host bridge description.
> >
> > Signed-off-by: Marcel Apfelbaum <address@hidden>
>
> I would like a unit test for various paths, they
> are part of guest ABI so we can never change them.
> Could you add a unit test please?
A QEMU unit-test you mean?
By the way, I found an issue with this patch, please do
not merge it yet.

> Also can you please quote the open firmware spec text
> that says this is the correct format?
Laszlo has found something, I'll look up something to quote, sure.

Thanks,
Marcel
> > ---
> > Laszlo worked on supporting pxb for OVMF and discovered
> > that there is a problem when booting devices from a PXB.
> >
> > This is a link to the latest QEMU series:
> >      https://www.mail-archive.com/address@hidden/msg302493.html
> >
> > Thanks,
> > Marcel
> >
> >   src/boot.c   | 1 -
> >   src/hw/pci.c | 2 +-
> >   2 files changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/src/boot.c b/src/boot.c
> > index ec59c37..a3bb13b 100644
> > --- a/src/boot.c
> > +++ b/src/boot.c
> > @@ -114,7 +114,6 @@ build_pci_path(char *buf, int max, const char *devname, 
> > struct pci_device *pci)
> >       } else {
> >           if (pci->rootbus)
> >               p += snprintf(p, max, "/address@hidden", pci->rootbus);
> > -        p += snprintf(p, buf+max-p, "%s", FW_PCI_DOMAIN);
> >       }
> >
> >       int dev = pci_bdf_to_dev(pci->bdf), fn = pci_bdf_to_fn(pci->bdf);
> > diff --git a/src/hw/pci.c b/src/hw/pci.c
> > index 0379b55..9e77af4 100644
> > --- a/src/hw/pci.c
> > +++ b/src/hw/pci.c
> > @@ -133,7 +133,7 @@ pci_probe_devices(void)
> >                   if (bus != lastbus)
> >                       rootbuses++;
> >                   lastbus = bus;
> > -                rootbus = rootbuses;
> > +                rootbus = bus;
> >                   if (bus > MaxPCIBus)
> >                       MaxPCIBus = bus;
> >               } else {
> > --
> > 2.1.0