Re: [Qemu-ppc] [PATCH 08/12] pci: allow 0 address for PCI IO regions

[Michael Roth]

Quoting Alexey Kardashevskiy (2014-08-26 04:14:27)
> On 08/19/2014 10:21 AM, Michael Roth wrote:
> > Some kernels program a 0 address for io regions. PCI 3.0 spec
> > section 6.2.5.1 doesn't seem to disallow this.
> 
> 
> I remember there was discussion about it but I forgot :) Why does it have
> to be a part of this patchset? Worth mentioning in the commit log I believe.

Unfortunately with ppc guests the first bar allocation tends to be the
0-address case, so to me it seemed necessary for a testable series. Can
simply document this in the series and re-send separately though.

> 
> 
> > 
> > Signed-off-by: Michael Roth <address@hidden>
> > ---
> >  hw/pci/pci.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> > index 351d320..9578749 100644
> > --- a/hw/pci/pci.c
> > +++ b/hw/pci/pci.c
> > @@ -1035,7 +1035,7 @@ static pcibus_t pci_bar_address(PCIDevice *d,
> >          /* Check if 32 bit BAR wraps around explicitly.
> >           * TODO: make priorities correct and remove this work around.
> >           */
> > -        if (last_addr <= new_addr || new_addr == 0 || last_addr >= 
> > UINT32_MAX) {
> > +        if (last_addr <= new_addr || last_addr >= UINT32_MAX) {
> >              return PCI_BAR_UNMAPPED;
> >          }
> >          return new_addr;
> > 
> 
> 
> -- 
> Alexey