From mboxrd@z Thu Jan 1 00:00:00 1970 From: Georgios Portokalidis Subject: Re: simple backend, frontend Date: Thu, 18 Nov 2004 17:57:46 +0000 Message-ID: References: Reply-To: Georgios Portokalidis Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: xen-devel-admin@lists.sourceforge.net Errors-To: xen-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Keir Fraser Cc: Deepak Manohar , mark.williamson@cl.cam.ac.uk, andrew.warfield@cl.cam.ac.uk, xen-devel@lists.sourceforge.net List-Id: xen-devel@lists.xenproject.org On Thu, 18 Nov 2004 17:50:41 +0000, Keir Fraser wrote: > > I have actually written some code for xen & xend allowing you to > > request the creation of an event channel and share a memory page. It's > > still work in progress, but it works fine. No crashes, very simple > > communication scheme. > > Yes, for some things, where xend does not need to keep state on the > channel (e.g., network address info, blkdev info) then having a way to > get xend to just be a dumb channel for your evtchn/shared-mem info is > undoubtedly a good idea. > > > The only possible problem i believe is the > > ctrl_if_register_receiver(). I think you can only register a single > > receiver for each control message type per domain. So even with a > > generic shared channel mechanism you will be able to use it just from > > a single driver/module. > > Use the subtype field, or create another field within your message, to > demux on. Then have a small proxy module that registers with > ctrl_if.c but then demuxes and forwards the message to the appropriate > driver based on the demux field. You could have drivers register with > the proxy module instead of ctrl_if. > Yeah, I thought the idea of a proxy module, but it is still a pain writing it. The way things are now the subtype is used to determine the action. The proxy module could actually offer a different interface to forward messages to xen.... It's definitely one of the todos > -- Keir > ------------------------------------------------------- This SF.Net email is sponsored by: InterSystems CACHE FREE OODBMS DOWNLOAD - A multidimensional database that combines robust object and relational technologies, making it a perfect match for Java, C++,COM, XML, ODBC and JDBC. www.intersystems.com/match8