[RFC] Xen Virtual Framebuffer

[Anthony Liguori <aliguori@us.ibm.com>]

Now that's 3.0.0's out, I thought it would be a good time to bring up 
the topic of framebuffer virtualization.

I threw together a proof-of-concept over the weekend of a simple virtual 
framebuffer/keyboard/mouse.  The basic design is have a vmalloc()'d 
buffer in the guest exposed as /dev/fb0 and mmap()'d in dom0.  There's 
also a simple message system for keyboard/mouse events.

The first frontend is a GTK widget with python bindings (so it can 
easily be embedded in a larger management app) and a small python app.  
Right now, the VT system seems to work fine and X starts quite happily 
(using the fbdev driver).  Clicking in the app captures the 
mouse/keyboard and ctrl+alt will release the capture.

There's a readme and an hg bundle in the tarball below that explains how 
to set things up.

Some interesting topics in this area are acceleration, whether we should 
implement our own X driver (or just enhance the fbdev driver since it 
uses no acceleration right now), and how to properly expose it over 
something like VNC.

As always, feedback is greatly appreciated.

http://www.cs.utexas.edu/users/aliguori/xen-vfb-20051205.tar.gz

Regards,

Anthony Liguori