Re: [Xen-devel] Re: [Qemu-devel] [PATCH 12/13] set vnc password from xenstore.

[Anthony Liguori]

Daniel P. Berrange wrote:
> On Thu, Aug 21, 2008 at 11:34:41PM +0200, Gerd Hoffmann wrote:
>   
> >   Hi,
> >     
> > Multiple monitor instances would be very useful anyway.
> >
> > Right now there is no way to use the monitor for libvirt-managed qemu
> > instances because libvirt uses the monitor.  Being able to both use
> > libvirt *and* have a monitor prompt to type commands would be great.
> >     
>
> I disagree - that means you'll no longer be able to trust what libvirt
> tells you about the VM, and libvirt won't have a guarenteed consistent
> view of the VM's state because things will be changed behind its back.
>   

A nice side effect of having multiple monitors is that you can implement 
a proper 'select' command.  This command would block and tell you about 
asynchronous events (like guest CD-ROM ejecting).  You could use this 
mechanism to notify libvirt when things changed because of other 
monitors too.

It's more work though from a libvirt perspective and you probably don't 
want users screwing around in the monitor anyway.

Regards,

Anthony Liguori

> Daniel
>