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

[Daniel P. Berrange]

On Thu, Aug 21, 2008 at 03:22:41PM -0500, Anthony Liguori wrote:
> Daniel P. Berrange wrote:
> >On Thu, Aug 21, 2008 at 03:14:26PM -0500, Anthony Liguori wrote:
> >  
> >>I don't really like this approach.  I don't want to have a totally 
> >>separate management interface just for Xend to use (via xenstore).
> >>
> >>Can't Xend use the monitor like every other management tool?
> >>    
> >
> >If the monitor really isn't sufficient, then I'd suggest allowing an
> >open file descriptor to be specified on the -vnc arg, eg
> >
> >  -vnc localhost:3,passwdfd=6
> >  
> 
> In general, I strongly dislike passing file descriptors like this.
> 
> >And then let QEMU read the password from this file descriptor. I'd rather
> >XenD just used the monitor though - it'll ultimately need to use it anyway
> >to perform disk/network hotplug amongst other things.
> >  
> 
> If there are reasons that Xend doesn't want to interact with the monitor 
> (for instance, if you want to support monitor redirection), we can 
> certainly discuss how to enhance the monitor (like having multiple 
> monitor instances).  Ultimately, we need to have everyone use the same 
> interface to interact with QEMU.

Based on my understanding of XenD code & requirements I think it is mostly
just a historical accident that it doesn't use the monitor - quite simply
when XenD first picked up QEMU there wasn't much of use the monitor could
provide. There were no disk/network/vnc commands for it to use, so it
did the easiest thing and read the data out of xenstore, since it was
there already.

Daniel
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