Re: [Qemu-devel] [Qemu-ppc] [QEMU PATCH v5 3/6] migration: extend VMStateInfo

[Halil Pasic]

On 10/13/2016 06:23 PM, Jianjun Duan wrote:
> 
> 
> On 10/13/2016 03:48 AM, Halil Pasic wrote:
>>
>>
>> On 10/13/2016 10:22 AM, Paolo Bonzini wrote:
>>>>> No, I disagree.  We shouldn't be worried about making intrusive changes
>>>>>>> to all invocations or declarations, if that leads to a simpler API.
>>>>>
>>>>> If VMStateInfo was meant for complete customization, then it was missing
>>>>> some parts. I think the API is indeed simpler. Just like
>>>>> definition for VMStateField. Not all of its fields are used all time.
>>> Code moves.  We can decide how much customization to allow of VMStateInfo.
>>>
>>> You said it: "Not all of its fields are used all time".  Likewise, not
>>> all arguments are used all time for get/put, but it's not an issue if they
>>> are still there!  So this patch is good, but at the same time VMS_LINKED is
>>> pointless.
>>>
>>> Paolo
>>>
>>
>> I'm fine with this. I just think, it would be nice if the contract between
>> the vmstate-core and the client code implementing VMStateInfo callbacks
>> could be documented, including when are certain parameters valid, what
>> they stand for, and how are they supposed to be used for the next version of
>> the patch. Just to improve readability. Would this be OK with everybody?
>>
>> By the way the flag VMS_SINGLE is documented as ignored. Should we drop
>> it?
>>
> I will prepare the VMStateInfo and QTAIL stuff as a separated series. If
> indeed VMS_SINGLE is ignored, I can drop it here. It is similar to
> VMS_LINKED situation.
> 
> Thanks,
> Jianjun

I think it's completely unrelated, so I would not lump it together with
the QTAILQ stuff.

How do you feel about the apidoc part?

Cheers,
Halil