From mboxrd@z Thu Jan 1 00:00:00 1970 From: Weidong Han Subject: Re: Xen 4.0.0 first release candidate / graphics passthru Date: Thu, 21 Jan 2010 17:52:15 +0800 Message-ID: <4B5823CF.6090907@intel.com> References: <20100112093245.GZ25902@reaktio.net> <20100121085407.GJ2861@reaktio.net> <20100121091215.GL2861@reaktio.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: 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: Jean Guyader Cc: "xen-devel@lists.xensource.com" , "Mr. Teo En Ming (Zhang Enming)" , Keir Fraser List-Id: xen-devel@lists.xenproject.org Jean Guyader wrote: > 2010/1/21 Pasi K=E4rkk=E4inen : > =20 >> On Thu, Jan 21, 2010 at 09:09:35AM +0000, Jean Guyader wrote: >> =20 >>> 2010/1/21 Pasi K=E4rkk=E4inen : >>> =20 >>>> On Tue, Jan 12, 2010 at 10:05:12AM +0000, Keir Fraser wrote: >>>> =20 >>>>> On 12/01/2010 09:32, "Pasi K=E4rkk=E4inen" wrote: >>>>> >>>>> =20 >>>>>>>> Does 4.0 include gpu passthru features? If not are there any upd= ated >>>>>>>> patches to try gpu passthru with 4.x? >>>>>>>> =20 >>>>>>> There is support (c/s 20144). >>>>>>> >>>>>>> =20 >>>>>> Btw is it possible now to specify a file to load the VGA bios from= ? >>>>>> earlier it was required to hardcode it into some header file or so= . >>>>>> =20 >>>>> I think it is hardcoded that qemu will take a copy of the host syst= em's BIOS >>>>> (i.e., for the primary host VGA). Other options would be easy to im= plement >>>>> I'm sure, if someone's interested. >>>>> >>>>> =20 >>>> I was just looking at same older mails, and it seems for example Teo= En Ming >>>> and others who got Xen VGA passthrough working had to copy the vgabi= os-pt.bin >>>> to tools/firmware/vgabios/ before building Xen. >>>> >>>> That's not very practical.. >>>> >>>> =20 >>> Right now the code copy the bios from 0xC0000. So if you want to pass= through >>> a secondary display adapter with the vga bios you are not copying the= right one, >>> that why this hack was for. >>> Surely the code could be modified to add an option to copy the bios o= f >>> the right card. >>> >>> =20 >> Ok, thanks for the info. >> >> Do I remember correctly that there was a problem with copying the BIOS= from some cards, >> or on some setups? And that's why the patch to load it from a file was= made? >> >> =20 > > Yes, I think that was because of that, and I'm not sure about the > intel IGD but I think that was causing some issue. > The code could have a cleanup and use sysfs to get the rombios, if I > works with the intel graphic card I think we should do that. > > Jean > =20 vbios copied from 0xC0000 doesn't work for some graphics cards, e.g.=20 Nvidia GS 8400, due to the vbios code is modified after initialization.=20 So it needs to load it from file. yes, it's not practical, Intel IGD=20 cards don't have this issue in our tests. One possible good solution is=20 to load vbios from expansion ROM of graphics cards, but we found=20 expansion ROM address are invalid for some graphics cards, even using=20 Linux upstream. It needs to look into Linux code. Regards, Weidong