WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

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

Rusty Russell wrote:
On Mon, 2007-06-11 at 10:16 +0200, Gerd Hoffmann wrote:
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.

Yes, I discussed this with Ben Herrenschmidt a couple of months ago.  It
would be better to provide a fb ioctl which X could use to describe
changed rectangles if available.  In the virtio case we could hand that
information through, and other virtualized framebuffers would be able to
use it similarly.

The X fbdev driver is going to make supporting a new fb ioctl pretty fun. It currently doesn't even support the existing fb ioctls and has a strange abstraction layer.

I reckon writing a new X driver from scratch (or based on something like the vnc X driver) would be easier in the long run.

Regards,

Anthony Liguori


Cheers,
Rusty.


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

<Prev in Thread] Current Thread [Next in Thread>