Re: [Xen-devel] Re: More virtio users

[Gerd Hoffmann <kraxel@redhat.com>]

   Hi,

> Framebuffer is an interesting one.  Virtio doesn't assume shared memory,
> so naively the fb you would just send outbufs describing changed memory.
> This would work, but describing rectangles is better.  A helper might be
> the right approach here

Rectangles work just fine for a framebuffer console.  They stop working 
once you plan to run any graphical stuff such as an X-Server on top of 
the framebuffer.  Only way to get notified about changes is page faults, 
i.e. 4k granularity on the linear framebuffer memory.

Related to Framebuffer is virtual keyboard and virtual mouse (or better 
touchscreen), which probably works perfectly fine with virtio.  I'd 
guess you can even reuse the input layer event struct for the virtio events.

Xen has virtual framebuffer, kbd & mouse, although not (yet?) in the 
paravirt_ops patch queue, so there is something you can look at ;)

cheers,
   Gerd