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. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
