I'll try not to be the opposite of what your G. Eliot quote says... 
If by VGA you actually mean emulated VGA, then yes, you can't use that
in para-virtual (or xenified) guest, as they don't have that sort of
device-model. The qemu-dm that is used by the HVM (unmodified) guests is
simply not there in para-virtual guests.
You can still use for example vncserver or ssh -X to run x-windows APPS
on your DomU - which is close to what you end up doing with qemu-dm in
the HVM guest too, since the HVM guest draws to a window within your
(X-)display on the host. 
I hope this is clear... 
--
Mats 
> -----Original Message-----
> From: xen-users-bounces@xxxxxxxxxxxxxxxxxxx 
> [mailto:xen-users-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of 
> James Colannino
> Sent: 28 June 2006 00:14
> To: xen-users@xxxxxxxxxxxxxxxxxxx
> Subject: [Xen-users] X-Windows on a virtual machine
>
> Hey everyone. I've been doing some googling to find information
> regarding the use of VGA. I'm having some trouble gaining a complete
> understanding of the matter, but it appears as if it is only 
> possible to
> use VGA on an unmodified operating system. Is this correct, 
> or would it
> be possible for me to install and use X-Windows on a domU installation
> with a modified kernel? Thanks very much in advance.
>
> James
> -- 
> My blog: http://www.crazydrclaw.com/ 
> My homepage: http://james.colannino.org/ 
>
> "Blessed is the man, who having nothing to say, abstains from giving
> wordy evidence of the fact." --George Eliot
>
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>
>
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