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

[Alexander Graf]

On 12.06.14 10:55, Paolo Bonzini wrote:
> 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.

Why don't we just ignore those config fields? They won't change during 
the lifetime of the guest anyway - and configuration needs to be the 
same on source and dest to work.


Alex