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 18:24:29 +0800 Message-ID: <4B582B5D.5020803@intel.com> References: <20100112093245.GZ25902@reaktio.net> <20100121085407.GJ2861@reaktio.net> <20100121091215.GL2861@reaktio.net> <4B5823CF.6090907@intel.com> <20100121095551.GN2861@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: <20100121095551.GN2861@reaktio.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: =?ISO-8859-1?Q?Pasi_K=E4rkk=E4inen?= Cc: "xen-devel@lists.xensource.com" , "Mr. Teo En Ming (Zhang Enming)" , Keir Fraser , Jean Guyader List-Id: xen-devel@lists.xenproject.org Pasi K=E4rkk=E4inen wrote: > On Thu, Jan 21, 2010 at 05:52:15PM +0800, Weidong Han wrote: > =20 >> Jean Guyader wrote: >> =20 >>> 2010/1/21 Pasi K=E4rkk=E4inen : >>> =20 >>> =20 >>>> On Thu, Jan 21, 2010 at 09:09:35AM +0000, Jean Guyader wrote: >>>> =20 >>>> =20 >>>>> 2010/1/21 Pasi K=E4rkk=E4inen : >>>>> =20 >>>>> =20 >>>>>> On Tue, Jan 12, 2010 at 10:05:12AM +0000, Keir Fraser wrote: >>>>>> =20 >>>>>> =20 >>>>>>> On 12/01/2010 09:32, "Pasi K=E4rkk=E4inen" wrote: >>>>>>> >>>>>>> =20 >>>>>>> =20 >>>>>>>>>> Does 4.0 include gpu passthru features? If not are there any u= pdated >>>>>>>>>> patches to try gpu passthru with 4.x? >>>>>>>>>> =20 >>>>>>>>>> =20 >>>>>>>>> There is support (c/s 20144). >>>>>>>>> >>>>>>>>> =20 >>>>>>>>> =20 >>>>>>>> Btw is it possible now to specify a file to load the VGA bios fr= om? >>>>>>>> earlier it was required to hardcode it into some header file or = so. >>>>>>>> =20 >>>>>>>> =20 >>>>>>> I think it is hardcoded that qemu will take a copy of the host sy= stem's BIOS >>>>>>> (i.e., for the primary host VGA). Other options would be easy to = implement >>>>>>> I'm sure, if someone's interested. >>>>>>> >>>>>>> =20 >>>>>>> =20 >>>>>> I was just looking at same older mails, and it seems for example T= eo En Ming >>>>>> and others who got Xen VGA passthrough working had to copy the vga= bios-pt.bin >>>>>> to tools/firmware/vgabios/ before building Xen. >>>>>> >>>>>> That's not very practical.. >>>>>> >>>>>> =20 >>>>>> =20 >>>>> Right now the code copy the bios from 0xC0000. So if you want to pa= ss through >>>>> a secondary display adapter with the vga bios you are not copying t= he right one, >>>>> that why this hack was for. >>>>> Surely the code could be modified to add an option to copy the bios= of >>>>> the right card. >>>>> >>>>> =20 >>>>> =20 >>>> Ok, thanks for the info. >>>> >>>> Do I remember correctly that there was a problem with copying the BI= OS from some cards, >>>> or on some setups? And that's why the patch to load it from a file w= as made? >>>> >>>> =20 >>>> =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 >>> =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. >> >> =20 > > So at this point should be add two things: > > 1) option in guest cfgfile telling from which card to copy the vbios fr= om > =20 I think adding an option in guest config file to indicate primary or=20 secondary gfx assignment can cover this. > 2) option to load the vbios from a file specified in guest cfgfile > =20 I don't prefer this. It involves much manual work for users. It's better=20 to find a general solution which is also easy to use. Regards, Weidong > How does that sound like?=20 > > -- Pasi > > =20