Re: [Qemu-devel] [PATCH 01/35] vmstate: Simplify test for CPU_SAVE_VERSION

[Andreas Färber]

Am 04.05.2012 13:59, schrieb Juan Quintela:
> Andreas Färber <address@hidden> wrote:
>> Am 04.05.2012 12:54, schrieb Juan Quintela:
>>> Some cpu's definitions define CPU_SAVE_VERSION, others not, but they have
>>
>> "CPUs' definitions"?
>>
>>> defined cpu_save/load.
>>
>> This commit message sounds wrong. Use of cpu_save/load is still coupled
>> to CPU_SAVE_VERSION AFAICS.
>>
>> What really changes is that vmstate_cpu_common is now registered whether
>> or not the target supports loading/saving the target-specific parts,
>> isn't it? Is that really useful? Either way, the commit message should
>> be updated.
> 
> For the cpus that weren't using CPU_SAVE_VERSION, we now register the
> system as unmigratable, so this don't matter.  For the cpus that support
> migration, it was always sent.  Code now is trivial to understand:
> 
> #if !defined(CONFIG_USER_ONLY)
>     vmstate_register(NULL, cpu_index, &vmstate_cpu_common, env);
>     vmstate_register(NULL, cpu_index, &vmstate_cpu, env);
> #endif

No, that's not what's in the patch.

> Befor it was a maze of ifdefs.  No change of behaviour with what we had
> before.  For either cpus that had[not]  support for migration or not.

Please look at the patch again - it turns the one-ifdef block into two
nested ifdefs. So therefore it is my understanding that - in lack of
unmigratable VMSDs this patch - possibly temporarily, not all patches
have arrived yet - changes the migration format in an odd way. In that
case we should consider reordering the patch within the series.

Andreas

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