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

[Greg Kurz <gkurz@linux.vnet.ibm.com>]

On Thu, 12 Jun 2014 10:55:42 +0200
Paolo Bonzini <pbonzini@redhat.com> 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.
> 
> Paolo
> 

BTW, can someone explain why we stream the device config ?

-- 
Gregory Kurz                                     kurzgreg@fr.ibm.com
                                                 gkurz@linux.vnet.ibm.com
Software Engineer @ IBM/Meiosys                  http://www.ibm.com
Tel +33 (0)562 165 496

"Anarchy is about taking complete responsibility for yourself."
        Alan Moore.