[Qemu-devel] Re: [RFC] New API for asynchronous monitor commands

[Anthony Liguori]

On 01/25/2010 07:08 AM, Luiz Capitulino wrote:
> On Fri, 22 Jan 2010 13:03:51 -0600
> Adam Litke<address@hidden>  wrote:
>
>   I like the patch, but I don't think it's a good idea to use this in
> synchronous commands as they will have to call QMPCompletion (not to
> mention unneeded suspend/resume calls).
>    

I think the value of having a single mechanism is that it gives us a 
common code path that's exercised for every command.  That helps avoid 
bugs in the long term.

I'd like to see the monitor move from a static table of commands to 
dynamic command registration.  IOW, we'd have something like:

monitor_register_cmd(name, args_type, help, params, my_qmp_command, 
my_opaque);

Given this API, it's pretty easy to write a wrapper that takes a simple 
synchronous callback without making such a concept core to the monitor 
infrastructure.

Notice that there's no user_print here.  I also would like to see us 
decouple QMP from the human monitor such that the human monitor was 
implemented purely in terms of QMP commands.  The core monitor 
infrastructure should really only deal with QMP and the human monitor 
should be an independent client.

Not all QMP concepts make sense for the human monitor and vice versa.  
The reason to start QMP as a mirror of the human monitor is to ensure 
management apps can have an easy transition.  However, once we're there, 
we should not continue duplicating QMP commands in the human monitor.

Regards,

Anthony Liguori