From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Daniel P. Berrange" Subject: Re: Split Device Driver for video card? Date: Wed, 9 Jan 2008 15:46:24 +0000 Message-ID: <20080109154624.GE8732@redhat.com> References: Reply-To: "Daniel P. Berrange" Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Teddy Song Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On Wed, Jan 09, 2008 at 10:37:12AM -0500, Teddy Song wrote: > > Hi, all. > > I am trying to figure out how split device drivers work in Xen. However, > when I start a guest domain, I only see the following fields showing up in > Xenstore: > > /local/domain/1/device/console/ ..... > /local/domain/1/device/vbd/769/ ..... > > I didn't see other /local/domain/1/device fields. Does it mean not all device > drivers in Xen follow the split device driver model? (in other words, not all > device drivers in Xen have a frontend and a backend) If that's true, does video > card device driver follow the split device driver model? The console node you see is actually the text mode console - this does not follow XEn's usual mode for split device drivers. The video card does follow the usual architecture - look for 'vfb' and 'vkbd' (keyboard/mouse) backend nodes in /local/domain/0/backend/{vfb,vkbd} and frontend nods in /local/domain/[guest id]/device/{vfb,vkbd}. The only slightly unusual thing about the video driver is that the backend is a 100% pure userspace driver, whereas disk & network have their backends in kernel-space. Dan. -- |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| |=- Perl modules: http://search.cpan.org/~danberr/ -=| |=- Projects: http://freshmeat.net/~danielpb/ -=| |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=|