From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1EucUE-0004gm-VK for qemu-devel@nongnu.org; Thu, 05 Jan 2006 16:17:31 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1EucUD-0004gA-9v for qemu-devel@nongnu.org; Thu, 05 Jan 2006 16:17:30 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1EucUC-0004g5-Va for qemu-devel@nongnu.org; Thu, 05 Jan 2006 16:17:29 -0500 Received: from [128.8.10.163] (helo=po1.wam.umd.edu) by monty-python.gnu.org with esmtp (Exim 4.34) id 1EucVq-00020O-CN for qemu-devel@nongnu.org; Thu, 05 Jan 2006 16:19:10 -0500 Date: Thu, 5 Jan 2006 16:13:11 -0500 From: "Jim C. Brown" Subject: Re: [Qemu-devel] PCI access virtualization Message-ID: <20060105211311.GA20203@jbrown.mylinuxbox.org> References: <1136456096.4464.90.camel@gimli> <200601051425.33430.paul@codesourcery.com> <200601051740.49151.mark.williamson@cl.cam.ac.uk> <200601051810.54954.paul@codesourcery.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200601051810.54954.paul@codesourcery.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Brook Cc: qemu-devel@nongnu.org On Thu, Jan 05, 2006 at 06:10:54PM +0000, Paul Brook wrote: > On Thursday 05 January 2006 17:40, Mark Williamson wrote: > > > - IRQ sharing. Sharing host IRQs between native and virtualized devices > > > is hard because the host needs to ack the interrupt in the IRQ handler, > > > but doesn't really know how to do that until after it's run the guest to > > > see what that does. > > > > Could maybe have the (inevitable) kernel portion of the code grab the > > interrupt, and not ack it until userspace does an ioctl on a special file > > (or something like that?). There are patches floating around for userspace > > IRQ handling, so I guess that could work. > > This still requires cooperation from both sides (ie. both the host and guest > drivers). > This would be a lot easier if linux supported user-space device drivers.. and I believe work is being done in that area. -- Infinite complexity begets infinite beauty. Infinite precision begets infinite perfection.