[Qemu-devel] Re: [PATCH 11/11] QMP: Command-line flag to enable control mode

[Avi Kivity <avi@redhat.com>]

On 06/23/2009 03:39 PM, Jan Kiszka wrote:
> Avi Kivity wrote:
>    
>> On 06/23/2009 02:53 PM, Jan Kiszka wrote:
>>      
>>>>> I'm talking about, just as one example, sitting in front of my gdb
>>>>> [frontend], doing guest kernel [driver] debugging and issuing "monitor
>>>>> whatever" commands from one place, ie. not having to switch between
>>>>> management app and debugging interface back and forth.
>>>>>
>>>>>
>>>>>            
>>>> Can gdb issue monitor commands?
>>>>
>>>>          
>>> Yes.
>>>
>>>        
>> How does one do that?  seems a very useful feature.
>>      
>
> By spawning an additional monitor terminal, but switching off its
> readline support (as that is handled by gdb).
>
> In case there is still someone out there not being aware of this ;) : we
> _do_ have support for multiple monitors in qemu already. Just try
> "-monitor X -serial mon:Y" with X!=Y.
>
>    
>> I could say that management can proxy the gdb packets and thus support
>> its own cli (in fact, it must if it wants to support live migration),
>> but that's really an edge case and I doubt anyone will do that, so you
>> have a good point.
>>      
>
> Proxying would mean interpreting all "classic" monitor commands to catch
> those that may interfere with the mgmt app state. I also don't think
> that is worth the effort.
>    

No, you would use the management system's cli which naturally enforces 
all of a user's permissions and is integrated with the GUI:

gui ----\
cli ----+---[ management server ] ---- [ libvirt ] ---- qemu
gdb ----/

That's the only setup that can support migration without dropping 
sessions.  That doesn't change the "I don't think it's worth the effort" 
state though.

-- 
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