Re: [Xen-devel] Re: [Qemu-devel] vnc port selection

["Daniel P. Berrange" <berrange@redhat.com>]

On Thu, Aug 21, 2008 at 01:35:57PM -0500, Anthony Liguori wrote:
> Avi Kivity wrote:
> >Gerd Hoffmann wrote:
> >>  Hi folks,
> >>
> >>Xen's qemu-dm version has a '-vncunused' command line switch which asks
> >>the internal vnc server to pick any unused tcp port to listen on.  The
> >>actual port is communicated to the outside world via xenstore.
> >>
> >>I'm looking for a reasonable way to implement that functionality in
> >>upstream qemu.  First, I think it shouldn't be a separate command line
> >>switch but an option for the existion -vnc switch.  Second, we need a
> >>way to communicate the port picked which isn't xen-specific.  Obvious
> >>choice is a monitor info subcommand.
> >>
> >>Comments?  Other suggestions?
> >>
> >>  
> >
> >Presumably -vncunused is passed by the management application, which 
> >knows about all domains.  Can't it figure out an unused port and pass 
> >it on?
> 
> An argument for this sort of semantics is that if you just launch 
> vncserver with no argument, it'll sit on the first unused port.  So 
> people are sort of used to this behavior.
> 
> >Alternatively, have the management application pass an fd denoting the 
> >socket.
> 
> If you are allocating the ports in the management tool, then just tell 
> QEMU what port to open up.  I don't think you gain anything passing an fd.

And it as I mentioned it'll make adding IPv6 support harder. 

Daniel
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