Re: [Qemu-devel] [RFC 00/11]: QMP feature negotiation support

[Markus Armbruster]

Anthony Liguori <address@hidden> writes:

> On 01/21/2010 03:09 PM, Luiz Capitulino wrote:
>> """
>> {"QMP": {"capabilities": ["async messages"]}}
>>
>> { "execute": "query-qmp-mode" }
>> {"return": {"mode": "handshake"}}
>>
>> { "execute": "change", "arguments": { "device": "vnc", "target": "password", 
>> "arg": "1234" } }
>> {"error": {"class": "QMPInvalidModeCommad", "desc": "The issued command is 
>> invalid in this mode", "data": {}}}
>>
>> { "execute": "async_msg_enable", "arguments": { "name": "STOP" } }
>> {"return": {}}
>>    
>
> Maybe:
>
> enable-capability "async messages"
> disable-capability "async messages"
>
> I think that's a bit more obvious and it means that a client doesn't
> have to maintain a mapping of features -> enable functions.  It's also
> strange to use an enable command to disable something.

Agree on both counts.  But why two commands?  Why not simply "capability
NAME VALUE"?  Works even for non-boolean capabilities.  I'm not
predicting we'll need such capabilities.