Re: [Qemu-devel] Re: [PATCH 08/11] QMP: Port balloon command

[Anthony Liguori <anthony@codemonkey.ws>]

Avi Kivity wrote:
> On 06/23/2009 07:29 AM, Luiz Capitulino wrote:
>>       else if (actual == 0)
>> -        monitor_printf(mon, "Ballooning not activated in VM\n");
>> +        monitor_printf_err(mon, "Ballooning not activated in VM\n");
>>       else
>> -        monitor_printf(mon, "balloon: actual=%d\n", (int)(actual>>  
>> 20));
>> +        monitor_printf_data(mon, "balloon: actual=%d\n", 
>> (int)(actual>>  20));
>>   }
>>    
>
> Control mode should always use bytes and seconds (and this should be 
> described in the spec).  You avoid rounding, and more importantly, 
> ambiguity and a source of unit conversion errors.

I'd actually like to see a lot more structure in this sort of output.  
For instance:

monitor_printf_list(mon, "balloon",
                               "actual", MON_TIME, actual,
                               NULL);

How this gets output can then be conditional on control mode vs. human 
mode.  In human mode, we can use human-friendly units like MBs.  In 
control mode, we would always use bytes.

> Patched that add a command to machine mode without updating the spec 
> should be automatically NACKed.
>
> We also need a way to discover that the command is available:

I think we want to version each command too.

Regards,

Anthony Liguori