Re: [Qemu-devel] [PATCH RFC 1/1] virtio: migrate config_vector

[Michael S. Tsirkin]

On Thu, May 14, 2015 at 10:24:15AM +0200, Paolo Bonzini wrote:
> 
> 
> On 13/05/2015 18:14, Michael S. Tsirkin wrote:
> > > - AFAICS, there's no easy way to add transport-specific subsections -
> > >   and simply adding config_vector in ccw would break compatibility
> > 
> > subsections break compatibility too.  The only way around that is to set
> > a flag to skip migrating config_vector for old machine types.
> 
> That's expected.  Subsections break compatibility because sometimes
> breaking migration is better than leaving a broken guest after migration.
> 
> Paolo

Right, and what happens is that some devices work kind of okay without
config interrupts? Christian - is this why you are trying to preserve
the broken behaviour for cross-version migration?

-- 
MST