On Tue, Aug 23, 2005 at 01:31:43PM -0400, Michel Dänzer wrote: > On Tue, 2005-08-23 at 10:00 -0700, Ian Romanick wrote: > > > > Keith Packard wrote: > > > On Tue, 2005-08-23 at 16:22 +0200, Stephane Marchesin wrote: > > > > > >>Ok, here is what came out of the irc meeting : > > >>- we don't need to enforce video memory ownership, but the drm needs to > > >>be able to track allocation owners anyway, for example if a process dies > > >>unexpectedly. > > > > > > How expensive would it be to protect one processes video memory from > > > another? I would like to be able to run applications for different users > > > on the screen at the same time and prevent both reading and writing of > > > the images. If not possible on current hardware, what would it take from > > > new hardware to make this possible? > > > > You'd need the same stuff that you need to protect system memory. You'd > > need a hardware MMU that could block the accesses. It might be possible > > to do it in software by looking at the command stream, but I suspect > > that would be pretty expensive. It would be worth a try, I suppose. > > Yeah, I don't expect it to be prohibitive; we're basically doing just > that for Radeons already. > > Another part would be to only allow mapping owned parts of the > framebuffer.
Is there any way to make that work without going to the kernel for each allocation? Personally I'd like to have the protection even if it degrades performance slightly. -- Ville Syrjälä [EMAIL PROTECTED] http://www.sci.fi/~syrjala/ ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
