Re: [Qemu-devel] Re: [PATCH 08/11] QMP: Port balloon command

[Luiz Capitulino <lcapitulino@redhat.com>]

On Thu, 25 Jun 2009 14:27:05 +0300
Dor Laor <dlaor@redhat.com> wrote:

> On 06/23/2009 09:38 PM, Anthony Liguori wrote:
> >
> > I wanted to respond to the top level, but here's what I see as the 
> > potential merge plan:
> >
> > 1) Make all commands return a value
> > 2) Add a mechanism to mark commands as being "structured"
> 
> This seems like a good idea.
> My original intent was to make the monitor interface a library.
> Various qemu users can link it with their favorite option: 
> json/dbus/rpm/xml/soap ;)

 Yes, having a library was suggested by Amit some months ago. The
problem is that it has various issues wrt maintainability.

 For example, libvirt is able to run two instances of different
versions of qemu at the same time. How to handle this if you
update libmonitor.so?

 I think people have agreed that having a protocol is good here, but
as Anthonhy puts it we need:

1. Choose between QMP and some kind of RPC
2. If RPC is choosen, what kind of RPC to use

> So, we should first harden up the monitor commands like 1),2), and 
> refactor the current
> monitor interface as a library above it.

 If I'm not mistaken, "structured" commands only makes sense with
QMP. The plan will be different if we choose RPC.

> > 3) Get the structured printfs in order.
> > 4) Merge
> >
> > I won't want QMP to be exposed as a usable interface until all 
> > commands are converted.  This means holding off on the last patch I 
> > think.  I don't think we'll get QMP for 0.11.  I think it's likely 
> > going to be a 0.12 feature.  However, I'd like to start merging this 
> > series as soon as humanly possible.  I think it's already pretty close.
> >
> If we push 'monitor standardization' into 0.11, the version will support 
> future
> implementations of the protocol.
> 
> Regards,
> Dor