Re: [Qemu-devel] [Qemu-stable] qmp commands get rejected

[Stefan Priebe <s.priebe@profihost.ag>]

Am 26.05.2013 03:23, schrieb mdroth:
> On Sat, May 25, 2013 at 01:09:50PM +0200, Stefan Priebe wrote:
>> Am 25.05.2013 00:32, schrieb mdroth:
>>> On Sat, May 25, 2013 at 12:12:22AM +0200, Stefan Priebe wrote:
>>>> Am 25.05.2013 00:09, schrieb mdroth:
>>>>>>>>> I would try to create a small example script.
>>>>>>>>
>>>>>>>> I use qmp-shell and other little scripts very often.
>>>>>>>>
>>>>>>>>> Am this be due to the fact that I don't wait for the welcome banner
>>>>>>>>> right now?
>>>>>>>>
>>>>>>>> If you're not reading from the socket, then you'll get the banner back
>>>>>>>> when
>>>>>>>> you read your first response. But qom-set shouldn't fail because of that.
>>>>>>
>>>>>> I can workaround it by adding this patch:
>>>>>> diff --git a/monitor.c b/monitor.c
>>>>>> index 62aaebe..9997520 100644
>>>>>> --- a/monitor.c
>>>>>> +++ b/monitor.c
>>>>>> @@ -4239,7 +4239,8 @@ static int monitor_can_read(void *opaque)
>>>>>>   static int invalid_qmp_mode(const Monitor *mon, const char *cmd_name)
>>>>>>   {
>>>>>>       int is_cap = compare_cmd(cmd_name, "qmp_capabilities");
>>>>>> -    return (qmp_cmd_mode(mon) ? is_cap : !is_cap);
>>>>>> +//    return (qmp_cmd_mode(mon) ? is_cap : !is_cap);
>>>>>> +    return ((is_cap > 0) ? 0 : (qmp_cmd_mode(mon) ? is_cap : !is_cap));
>>>>>>   }
>>>>>
>>>>> I think this is unrelated to your original issue. If you issue
>>>>> 'qmp_capabilities' command more than once you will get CommandNotFound,
>>>>> and that behavior seems to be present even with v1.3.0. This patch seems
>>>>> to be masking the problem you're having (which seems to be state from
>>>>> previous monitor sessions/connections leaking into subsequent ones).
>>>>
>>>> That sounds reasonable. I'm using proxmox / PVE which does a lot of
>>>> qmp queries in the background. So i might see situations where X
>>>> connections in parallel do qmp queries.
>>>>
>>>>> It's possible the GSource-based mechanism for handling I/O for chardev
>>>>> backends is causing a difference in behavior. Still not sure exactly
>>>>> what's going on though.
>>>> Can i revert some patches to test?
>>>
>>> I think somewhere prior to this one should be enough to test:
>>>
>>> 2ea5a7af7bfa576a5936400ccca4144caca9640b
>>
>> YES! I used 2ea5a7af7bfa576a5936400ccca4144caca9640b~1 for my tests
>> and this works absoluty fine.
>
> Turns out the real culprit was a few commits later:
>
> 9f939df955a4152aad69a19a77e0898631bb2c18
>
> I've sent a workaround this fixes things for QMP, but we may need a more
> general fix. Please give it a shot and see if it fixes your issues:
>
> http://article.gmane.org/gmane.comp.emulators.qemu/213106

no i got again:
The command qom-set has not been found  JSON Reply: {"id": "21677:2", 
"error": {"class": "CommandNotFound", "desc": "The command qom-set has 
not been found"}} JSON Query: 
{"execute":"qom-set","id":"21677:2","arguments":{"value":2,"path":"machine/peripheral/balloon0","property":"guest-stats-polling-interval"}} 
at /usr/share/perl5/PVE/QMPClient.pm line 101.

Stefan