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Date: Thu, 14 May 2015 11:56:51 +0200
From: "Michael S. Tsirkin" <mst@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH RFC 1/1] virtio: migrate config_vector
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>, borntraeger@de.ibm.com, qemu-devel@nongnu.org, jjherne@linux.vnet.ibm.com

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