Re: [Qemu-devel] [PATCH] target-ppc: Add @cpu_dt_id into migration stream

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 03/28/2014 12:07 AM, Alexey Kardashevskiy wrote:
> On 03/27/2014 11:57 PM, Peter Maydell wrote:
>> On 27 March 2014 12:49, Alexey Kardashevskiy <aik@ozlabs.ru> wrote:
>>> On 03/27/2014 11:37 PM, Andreas Färber wrote:
>>>> Am 27.03.2014 03:41, schrieb Alexey Kardashevskiy:
>>>>> This should prevent the destination guest from misbehaving when
>>>>> the threads number is different in "-smp" command.
>>>>
>>>> Sorry, I don't understand. When migrating, surely -smp needs to be the
>>>> same on source and destination, so how can they differ?
>>>
>>>
>>> The idea is that "-smp" does not migrate and if we run source and
>>> destination guests with different numbers in -smp, we end up with weird
>>> machine
>>
>> Yes, so don't do that. As I understand it:
>>  (1) if you don't run QEMU with the exact same command line
>>      and config at both ends then migration won't work
>>  (2) we don't guarantee to detect and cleanly fail if you
>>      don't do (1)
>>
>> It would probably be nice if we did detect config mismatches,
> 
> Yep, we do not send the device tree (as libvirt does). Pure command line
> matching won't work.
> 
>> but that seems to me like a problem we should be addressing
>> more globally than just for one particular config item for
>> one particular target...


Ok. So. Let's assume I want to implement migration of "-smp" parameters.
What would be the correct way of doing this in terms of the current QOM
principles? Thanks.



> 
> This is lot bigger that the issue I am trying to solve by this patch...
> Still nack?





-- 
Alexey