Re: [Qemu-devel] [PATCH RFC 8/8] virtio: add endian-ambivalent support to VirtIODevice

[Paolo Bonzini]

Il 12/06/2014 09:43, Greg Kurz ha scritto:
> Since we know that 0 < max_nr_ports < 32,  is it acceptable to guess
> the correct endianness with a heuristic ?
>
> if (max_nr_ports > tswap32(s->config.max_nr_ports)) {
>         max_nr_ports = bswap32(max_nr_ports);
> }
>
> if (max_nr_ports > tswap32(s->config.max_nr_ports)) {
>         return -EINVAL;
> }

Yes, I guess it is acceptable.  So first you should fix the code to 
always serialize fields as big-endian, and then apply this little hack 
and virtio_tswap on top of the previous change.

Paolo