Re: [Qemu-devel] [patch 01/18] qemu: add pci helper functions

[Anthony Liguori]

Paul Brook wrote:
> On Wednesday 04 February 2009, Marcelo Tosatti wrote:
>   
> > +PCIDevice *pci_find_device(int bus_num, int slot)
> > +{
> > +    int devfn;
> > +    PCIDevice *d;
> > +    PCIBus *bus = pci_find_bus(bus_num);
> > +
> > +    if (!bus)
> > +        return NULL;
> > +
> > +    for(devfn = 0; devfn < 256; devfn++) {
> > +        d = bus->devices[devfn];
> > +            if (d && PCI_SLOT(devfn) == slot)
> > +                return d;
> > +    }
> > +    return NULL;
> > +}
> >     
>
> This loop is bogus. You already know the devfn from the slot.
> It's also completely busted if you have multifunction devices.
>   

It should probably try a bit harder to handle the multifunction case.  
You know your device is bus->devices[slot * 8] but you should also check 
slot * 8 + 1..slot * 8 + 7 to see if there are any sub functions and 
return NULL or something.

Regards,

Anthony Liguori

> Paul
>
>
>