[libvirt] [Qemu-devel] Re: Libvirt debug API

Anthony Liguori anthony at codemonkey.ws
Mon Apr 26 13:14:08 UTC 2010

On 04/25/2010 09:50 AM, Avi Kivity wrote:
> On 04/23/2010 09:33 PM, Anthony Liguori wrote:
>>> This is a different ambiguity, about the semantic results of the 
>>> commands,
>>> where as I'm refering to the execution order. If I look at a libvirt 
>>> log
>>> file and see a set of JSON commands logged, I want to know that this 
>>> ordering
>>> from the logs, was indeed the same as order in which qemu processed 
>>> them. If
>>> you have two separate monitor connection you can't be sure of the 
>>> order of
>>> execution. It is key for our bug troubleshooting that given a 
>>> libvirt log
>>> file, we can replay the JSON commands again and get the same 
>>> results. Two
>>> monitor connections is just increasing complexity of code without any
>>> tangible benefit.
>> I think you're assuming direct access to the second monitor?  I'm not 
>> suggesting that.  I'm suggesting that libvirt is still the one 
>> submitting commands to the second monitor and that it submits those 
>> commands in lock step.
> What about protocol extensions?  For instance, pretend libvirt doesn't 
> support async messages, what would it do when it receives one from the 
> user's monitor?

Protocol extensions could not be supported in this model.  I agree, 
that's unfortunate.


Anthony Liguori

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