Re: [Qemu-devel] [PATCH] define qemukvm-1.2 machine type

[Marcelo Tosatti <mtosatti@redhat.com>]

On Fri, Jan 18, 2013 at 12:34:57PM -0500, Paolo Bonzini wrote:
> > > version_id and minimum_version_id should be changed to 2, as the
> > > comment indicates.
> > 
> > But won't that mean we have to carry that patch forever, and while we carry
> > that patch we can never migrate from Fedora qemu to an upstream qemu instance?
> > I'd like to avoid carrying any incompatibility forward, if possible.
> 
> To some extent you have to choose between backwards- and forwards-
> compatibility.  But I think that you can achieve what you want
> by leaving version_id to 3, while setting minimum_version_id to 2.
> 
> Paolo

What about

"Problem is it uses acpi_load_old, when reading from qemu-kvm 1.2 (which
advertises format as V2), which reads 4*16 bits (instead of 16 bits)
for en/sts fields. So it can corrupt incoming migration data."