Re: [Qemu-devel] [PATCH v4 4/5] slirp: VMStatify socket level

[Samuel Thibault]

Dr. David Alan Gilbert, on mar. 28 févr. 2017 17:00:17 +0000, wrote:
> * Samuel Thibault (address@hidden) wrote:
> > Dr. David Alan Gilbert, on mar. 28 févr. 2017 16:54:46 +0000, wrote:
> > > I'm thinking one way to do it without changing the version would
> > > be to use the existing value for IPv4, and on reading allow any other
> > > value for IPv6 (or just the ones we know about); that would make
> > > it inwards migration compatible.
> > 
> > Right. I don't know if that's enough for QEMU requirements.
> 
> If you change the version number you break backwards migration anyway;
> but doing what I suggested would keep backwards working in most cases.

Sure, but in some cases we're breaking upward compatibility *silently*.

Samuel