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

[Avi Kivity]

On 06/23/2009 06:47 PM, Anthony Liguori wrote:
> Avi Kivity wrote:
> > > stop
> > > cont
> >
> > These certainly seem very synchronous to me.
>
> Not with KVM.  You have to wait for the VCPU threads to get notified 
> and stop.  Maybe it's not a big deal to block during this.

If a command returns immediately, we shouldn't try to make it asynchronous.

> > > migrate
> > > balloon 
> >
> > Isn't balloon synchronous?  It sets the target and exits 
> > immediately.  We don't want command completion to depend on the guest.
>
> I can see a use-case for having balloon only return when the target 
> has been reached by the guest.

There's 'info balloon' for that, and maybe request a notification.  
Waiting for the guest is asking for trouble.  What if you want to set 
the balloon to a different target? you have two different balloon 
commands running?

> I think I can buy the event stuff.  As long as we version QMP 
> protocol, we can potentially fix this down the road.

Alternatively we can introduce a tag, and so make all commands asynchronous:

  @tag1 commit
  @tag1 = committed
  @tag1 + OK have fun

Or go with the jsonrpc thing that has all this built in.

--
error compiling committee.c: too many arguments to function