Remote X connection to NetBSD DomU ?

[Bruno Damour <llama%ruomad.net@localhost>]

Hello,
I have successfully built a NetBSD DomU on my Opensolaris Dom0. 
Everything runs fine, but now I would like to get an X desktop from my 
NetBSD DomU.
I cannot find the setup.
I installed gdm and enable XDMCP in custom.conf. I try to connect from 
my Dom0 with Xephyr, and it presents me the gdm login screen.
If I try to login, it gets back to login screen.
If I try a Xlient or failsafe session, I get a graphic console but 
cannots strat any  wm from it (I tried fluxbox)
Is there something preventing X from properly start because there is no 
display :0 ?
I see in X logs this cryptical message :

Fatal server error:
xf86OpenConsole: No console driver found
   Supported drivers: pcvt, wscons
   Check your kernel's console driver configuration and /dev entries

Make me suspect the problem is not an Xauth problem.

Any clue would be highly appreciated as my googling doesn't get me anywhere.

Thanks

Bruno