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? Thanks in advance. Best regards, Teddy _________________________________________________________________ Get the power of Windows + Web with the new Windows Live. http://www.windowslive.com?ocid=TXT_TAGHM_Wave2_powerofwindows_012008 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
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? Thanks in advance. Best regards, Teddy _________________________________________________________________ Make distant family not so distant with Windows Vista® + Windows Live™. http://www.microsoft.com/windows/digitallife/keepintouch.mspx?ocid=TXT_TAGLM_CPC_VideoChat_distantfamily_012008 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Daniel P. Berrange
2008-Jan-09 15:46 UTC
Re: [Xen-devel] Split Device Driver for video card?
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 -=| _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Teddy, are you running an HVM domain? If so, you won''t see many device nodes in Xenstore since HVM domains don''t use split device drivers for most things. Cheers, Mark On Wednesday 09 January 2008, Daniel P. Berrange wrote:> 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.-- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel