Re: [Qemu-devel] [PATCH 01/11] QMP: Introduce specification file

[Anthony Liguori <anthony@codemonkey.ws>]

Avi Kivity wrote:
>> I don't mind if this ends up looking like JSON, but I don't want to 
>> have to enforce that it's remains JSON compatible in the long term.  
>> We should have our own grammar that we can version and that people 
>> can use as the basis of a client.
>
> That really reduces the attractiveness of the whole thing.  Writing 
> parsers and emitters should be an optional part of writing a qemu 
> control program, not a required part.
I really disagree but this thread is also killing my soul :-)

Whatever we do for QMP, it will not be enabled for 0.11 so we have 6 
months to get it right.  In the interest of moving forward and writing 
patches instead of emails, here's what I'm thinking:

1) Update the QMP patches to support return values for monitor commands
2) Update patches to support structured command output
3) Update the patches to support higher level data types (like lists and 
dictionaries)
4) For whatever the emission format is, provide a regular grammar to 
parse that output

I will commit a patch series that meets these goals.

Given a regular grammar, it's extremely easy to convert to outputting 
JSON, XML, or whatever.  We can keep arguing about whether JSON is the 
right format long term.  However, I don't want the useful work of 
conversing monitor commands to satisify 1-3 to be held up by arguments 
about the emission format which is largely unrelated to the command 
conversions.

Regards,

Anthony Liguori