Re: [Qemu-devel] [PATCH 3/3] prep: improve Raven PCI host emulation

[Hervé Poussineau]

Richard Henderson a écrit :
> On 08/23/2013 11:52 AM, Hervé Poussineau wrote:
> > +    uint8_t buf[4];
> > +    uint64_t val;
> > +
> > +    if (s->contiguous_map == 0) {
> > +        /* 64 KB contiguous space for IOs */
> > +        addr &= 0xFFFF;
> > +    } else {
> > +        /* 8 MB non-contiguous space for IOs */
> > +        addr = (addr & 0x1F) | ((addr & 0x007FFF000) >> 7);
> > +    }
> > +
> > +    address_space_read(&s->pci_io_as, addr + 0x80000000, buf, size);
> > +    memcpy(&val, buf, size);
> > +    return val;
>
> This memcpy can't be right, especially for big-endian host.

pci_io_as is supposed to contain words/longs in little-endian mode (PCI 
is always little-endian).
prep_io_ops endianness is DEVICE_LITTLE_ENDIAN, so, AFAIK, this means 
that returned val should be LE.
Why should it break on big-endian hosts?

Regards,

Hervé