Re: [Qemu-devel] vmstate: struct (VMS_STRUCT) migration

[Peter Maydell]

On 2 July 2014 15:04, Alexey Kardashevskiy <address@hidden> wrote:
> On 06/25/2014 04:36 PM, Alexey Kardashevskiy wrote:
>> Hi!
>>
>> VMStateDescription supports enclosed VMStateDescription's via .vmsd. This
>> is used in multiple places and VMStateDescription definitions look the same
>> way - name, version_id, minimum_version_id, etc.
>>
>> QEMU handles first level VMStateDescription and enclosed VMStateDescription
>> slightly different - for the latter it ignores the version_id from the
>> source and always uses the version_id on the destination side so version
>> fields are useless (code is below).
>>
>> Is that by design? Or a bug? I cannot see how we could fix it without
>> breaking backward compatibility but I am sure the community does know that :)
>>
>> If this is by design, it probably makes sense to remove unused
>> version_id/minimum_version_id fields completely for vmsd's which we know
>> are enclosed (or embedded?).
>>
>> What do I miss here? Thanks!
>
> Anyone? :)

Ccing Juan would probably help. I'm not sure the current behaviour
makes a great deal of sense...

thanks
-- PMM