Re: [PATCH v8 --for 4.6 COLO 02/25] docs/libxl: Introduce COLO_CONTEXT to support migration v2 colo streams

[Yang Hongyang <yanghy@cn.fujitsu.com>]

On 07/16/2015 05:45 PM, Andrew Cooper wrote:
> On 16/07/15 07:32, Yang Hongyang wrote:
>>
>>
>> On 07/16/2015 12:52 AM, Andrew Cooper wrote:
>>> On 15/07/15 10:18, Yang Hongyang wrote:
>>>> From: Wen Congyang <wency@cn.fujitsu.com>
>>>>
>>>> It is the negotiation record for COLO.
>>>> Primary->Secondary:
>>>> control_id      0x00000000: Secondary VM is out of sync, start a new
>>>> checkpoint
>>>> Secondary->Primary:
>>>>                   0x00000001: Secondary VM is suspended
>>>>                   0x00000002: Secondary VM is ready
>>>>                   0x00000003: Secondary VM is resumed
>>>>
>>>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>>>> Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
>>>> ---
>>>>    docs/specs/libxl-migration-stream.pandoc | 22 +++++++++++++++++++++-
>>>>    tools/libxl/libxl_sr_stream_format.h     | 11 +++++++++++
>>>>    tools/python/xen/migration/libxl.py      |  9 +++++++++
>>>>    3 files changed, 41 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/docs/specs/libxl-migration-stream.pandoc
>>>> b/docs/specs/libxl-migration-stream.pandoc
>>>> index c24a434..5986273 100644
>>>> --- a/docs/specs/libxl-migration-stream.pandoc
>>>> +++ b/docs/specs/libxl-migration-stream.pandoc
>>>> @@ -121,7 +121,9 @@ type         0x00000000: END
>>>>
>>>>                 0x00000004: CHECKPOINT_END
>>>>
>>>> -             0x00000005 - 0x7FFFFFFF: Reserved for future _mandatory_
>>>> +             0x00000005: COLO_CONTEXT
>>>> +
>>>> +             0x00000006 - 0x7FFFFFFF: Reserved for future _mandatory_
>>>>                 records.
>>>>
>>>>                 0x80000000 - 0xFFFFFFFF: Reserved for future _optional_
>>>> @@ -215,3 +217,21 @@ A checkpoint end record marks the end of a
>>>> checkpoint in the image.
>>>>        +-------------------------------------------------+
>>>>
>>>>    The end record contains no fields; its body_length is 0.
>>>> +
>>>> +COLO\_CONTEXT
>>>> +--------------
>>>> +
>>>> +A COLO context record contains the control information for COLO.
>>>> +
>>>> +     0     1     2     3     4     5     6     7 octet
>>>> +    +------------------------+------------------------+
>>>> +    | control_id             | padding                |
>>>> +    +------------------------+------------------------+
>>>> +
>>>> +--------------------------------------------------------------------
>>>> +Field            Description
>>>> +------------     ---------------------------------------------------
>>>> +control_id       0x00000000: Secondary VM is out of sync, start a
>>>> new checkpoint
>>>> +                 0x00000001: Secondary VM is suspended
>>>> +                 0x00000002: Secondary VM is ready
>>>> +                 0x00000003: Secondary VM is resumed
>>>
>>> This style of table in pandoc need to be terminated with a line of
>>> -------, just like the head of the table.
>>
>> Ok
>>
>>>
>>> Also, I wonder at the name "COLO_CONTEXT".  CONTEXT implies an
>>> associated blob of data, but this is not the case here.  Here, it is
>>> more of a status update, with expected actions on some states.
>>
>> True, could you suggest a better name? sorry for my bad English...
>
> In hindsight, I would also avoid putting COLO in the name.
>
> How about CHECKPOINT_SECONDARY_STATE ?

 From my another mail, I explained the COLO_CONTEXT, do you still
suggest CHECKPOINT_SECONDARY_STATE? IMO, it's more like a sync
command?

>
> You also want to note that this record should currently only be found in
> the libxl backchannel.
>
> ~Andrew
> .
>

-- 
Thanks,
Yang.