Re: [PATCH v3 4/9] qapi/misc: Restrict balloon-related commands to machine code

[Philippe Mathieu-Daudé]

On 5/27/20 6:49 AM, Markus Armbruster wrote:
> Philippe Mathieu-Daudé <address@hidden> writes:
> 
>> On 5/26/20 11:31 AM, Philippe Mathieu-Daudé wrote:
>>> +Laurent
>>>
>>> On 5/26/20 11:04 AM, Markus Armbruster wrote:
>>>> Philippe Mathieu-Daudé <address@hidden> writes:
>>>>
>>>>> On 5/26/20 9:38 AM, Markus Armbruster wrote:
>>>>>> Philippe Mathieu-Daudé <address@hidden> writes:
>>>>>>
>>>>>>> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
>>>>>>
>>>>>> A brief note on why restricting "to machine code" is useful would be
>>>>>> nice.  Same for the other patches.
>>>>>>
>>>>>> Acked-by: Markus Armbruster <address@hidden>
>>>>>>
>>>>>
>>>>> What about this?
>>>>>
>>>>> "QEMU can do system-mode and user-mode emulation.
>>>>> Only system mode emulate a machine.
>>>>> Remove this feature from the user-mode emulation."
>>>>
>>>> Is is a feature of user-mode emulation before the patch?  Or is it just
>>>> dead code?
>>>>
>>>> Hint: QMP commands tend to be dead code when the program doesn't expose
>>>> a QMP monitor :)
>>>
>>> Maybe a 'corollary' question, "How user-mode users use QMP?"
>>>
>>
>> I can't find a way to start a user-mode process with a QMP socket, is
>> there one?
> 
> As far as I can tell, only qemu-system-FOO and qemu-storage-daemon
> provide QMP monitors:
> 
> * Monitors need to be initialized with monitor_init().  Two callers:
>   monitor_init_hmp(), monitor_init_qmp().
> 
> * monitor_init() calls both, and is the common wat to create a monitor.
>   Called by vl.c via monitor_init_opts(), and by qemu-storage-daemon.
> 
> * monitor_init_hmp() has additional callers, but HMP doesn't matter
>   here.
> 

OK good to know. I'll reword the patch description, but also check if
there isn't a simpler way to avoid pulling QMP code in user-mode builds
first.

Thanks!

Phil.