[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-ppc] [Qemu-devel] [PATCH] target-ppc: Add @cpu_dt_id into migr
Re: [Qemu-ppc] [Qemu-devel] [PATCH] target-ppc: Add @cpu_dt_id into migration stream
Fri, 11 Apr 2014 00:35:47 +1000
Mozilla/5.0 (X11; Linux i686 on x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0
On 04/10/2014 10:10 PM, Alexander Graf wrote:
> On 08.04.14 03:26, Alexey Kardashevskiy wrote:
>> 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 <address@hidden> 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
>>>> 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.
> You don't. The migration protocol doesn't migrate configuration. If you
> want to start to transfer VM configuration (which I'd be all in for), do it
> properly and transfer _all_ configuration.
Then what is the purpose of many, many VMSTATE_.*_EQUAL?
And I do not want to send configuration by the proposed patch, I want to
make sure that the new guest is able to continue. Why exactly is this bad?