Re: [Qemu-devel] [PATCH V11 09/17] qmp: add interface query-snapshots

[Wenchao Xia]

>>   # Statistics of a virtual block device or a block backing device.
>> diff --git a/qmp-commands.hx b/qmp-commands.hx
>> index 1e0e11e..6b20684 100644
>> --- a/qmp-commands.hx
>> +++ b/qmp-commands.hx
>> @@ -1765,6 +1765,61 @@ EQMP
>>       },
>>   
>>   SQMP
>> +query-snapshots
>> +---------------
>> +
>> +Show the internal consistent snapshot information
>> +
>> +Each snapshot is represented by a json-object. The returned value
>> +is a json-array of all snapshots
>> +
>> +Each json-object contain the following:
>> +
>> +- "id": unique snapshot id (json-string)
>> +- "name": internal snapshot name (json-string)
>> +- "vm-state-size": size of the VM state in bytes (json-int)
>> +- "date-sec": UTC date of the snapshot in seconds (json-int)
>> +- "date-nsec": fractional part in nanoseconds to be used with
>> +               date-sec(json-int)
>> +- "vm-clock-sec": VM clock relative to boot in seconds (json-int)
>> +- "vm-clock-nsec": fractional part in nanoseconds to be used with
>> +                   vm-clock-sec (json-int)
>> +
>> +Example:
>> +
>> +-> { "execute": "query-snapshots" }
>> +<- {
>> +      "return":[
>> +         {
>> +            "id": "1",
>> +            "name": "snapshot1",
>> +            "vm-state-size": 0,
>> +            "date-sec": 10000200,
>> +            "date-nsec": 12,
>> +            "vm-clock-sec": 206,
>> +            "vm-clock-nsec": 30
> 
> Not your patch's fault, but here goes anyway: I dislike this
> representation of time.
> 
> QMP has time in seconds, milliseconds, nanoseconds, (seconds,
> milliseconds) and (seconds, nanoseconds).  There has been no adult
> supervision, obviously (I may say that, because it's as much my fault as
> it's anybody else's).
> 
> The sanest one by far is nanoseconds.  Good for 2^63 of them.  Since pi
> seconds is a nanocentury, good for 2^63 / (pi * 1e9) centuries, which
> should be safely beyond your retirement age.
> 
  OK, will insert a patch before removing "vm-clock-sec". Have one
question: how to declare uint64_t in qmp-schema.json?


>> +         },
>> +         {
>> +            "id": "2",
>> +            "name": "snapshot2",
>> +            "vm-state-size": 34000000,
>> +            "date-sec": 13000200,
>> +            "date-nsec": 32,
>> +            "vm-clock-sec": 406,
>> +            "vm-clock-nsec": 31
>> +         }
>> +      ]
>> +   }
>> +
>> +EQMP
>> +
>> +    {
>> +        .name       = "query-snapshots",
>> +        .args_type  = "",
>> +        .mhandler.cmd_new = qmp_marshal_input_query_snapshots,
>> +    },
>> +
>> +SQMP
>>   query-blockstats
>>   ----------------
> 


-- 
Best Regards

Wenchao Xia