Re: Xen 4.0.0 first release candidate / graphics passthru

[Weidong Han <weidong.han@intel.com>]

Sander Eikelenboom wrote:
> Hello Weidong,
>
> Hmm I guess I have missed something, are all other (IGD etc.) VGA passthrough patches allready merged in 4.0.0-rc1 ?
>   
No, I sent the patchset months ago, but not checked in.
> And should it work then with both 2.6.31.6-pvops and  2.6.18.8-xen dom0 ?
>   

We will rebase the patchset for both 2.6.18 and pvops dom0, and resend 
if for check in after xen 4.0.

Regards,
Weidong
> --
> Sander
>
>
>
>
> Thursday, January 21, 2010, 11:24:29 AM, you wrote:
>
>   
>> Pasi Kärkkäinen wrote:
>>     
>>> On Thu, Jan 21, 2010 at 05:52:15PM +0800, Weidong Han wrote:
>>>   
>>>       
>>>> Jean Guyader wrote:
>>>>     
>>>>         
>>>>> 2010/1/21 Pasi Kärkkäinen <pasik@iki.fi>:
>>>>>   
>>>>>       
>>>>>           
>>>>>> On Thu, Jan 21, 2010 at 09:09:35AM +0000, Jean Guyader wrote:
>>>>>>     
>>>>>>         
>>>>>>             
>>>>>>> 2010/1/21 Pasi Kärkkäinen <pasik@iki.fi>:
>>>>>>>       
>>>>>>>           
>>>>>>>               
>>>>>>>> On Tue, Jan 12, 2010 at 10:05:12AM +0000, Keir Fraser wrote:
>>>>>>>>         
>>>>>>>>             
>>>>>>>>                 
>>>>>>>>> On 12/01/2010 09:32, "Pasi Kärkkäinen" <pasik@iki.fi> wrote:
>>>>>>>>>
>>>>>>>>>           
>>>>>>>>>               
>>>>>>>>>                   
>>>>>>>>>>>> Does 4.0 include gpu passthru features? If not are there any updated
>>>>>>>>>>>> patches to try gpu passthru with 4.x?
>>>>>>>>>>>>                 
>>>>>>>>>>>>                     
>>>>>>>>>>>>                         
>>>>>>>>>>> There is support (c/s 20144).
>>>>>>>>>>>
>>>>>>>>>>>               
>>>>>>>>>>>                   
>>>>>>>>>>>                       
>>>>>>>>>> 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.
>>>>>>>>>>             
>>>>>>>>>>                 
>>>>>>>>>>                     
>>>>>>>>> I think it is hardcoded that qemu will take a copy of the host system's BIOS
>>>>>>>>> (i.e., for the primary host VGA). Other options would be easy to implement
>>>>>>>>> I'm sure, if someone's interested.
>>>>>>>>>
>>>>>>>>>           
>>>>>>>>>               
>>>>>>>>>                   
>>>>>>>> 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 vgabios-pt.bin
>>>>>>>> to tools/firmware/vgabios/ before building Xen.
>>>>>>>>
>>>>>>>> That's not very practical..
>>>>>>>>
>>>>>>>>         
>>>>>>>>             
>>>>>>>>                 
>>>>>>> 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 of
>>>>>>> the right card.
>>>>>>>
>>>>>>>       
>>>>>>>           
>>>>>>>               
>>>>>> 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?
>>>>>>
>>>>>>     
>>>>>>         
>>>>>>             
>>>>> 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
>>>>>   
>>>>>       
>>>>>           
>>>> vbios copied from 0xC0000 doesn't work for some graphics cards, e.g.  
>>>> Nvidia GS 8400, due to the vbios code is modified after initialization.  
>>>> So it needs to load it from file. yes, it's not practical, Intel IGD  
>>>> cards don't have this issue in our tests.  One possible good solution is  
>>>> to load vbios from expansion ROM of graphics cards, but we found  
>>>> expansion ROM address are invalid for some graphics cards, even using  
>>>> Linux upstream.  It needs to look into Linux code.
>>>>
>>>>     
>>>>         
>>> So at this point should be add two things:
>>>
>>> 1) option in guest cfgfile telling from which card to copy the vbios from
>>>   
>>>       
>> I think adding an option in guest config file to indicate primary or 
>> secondary gfx assignment can cover this.
>>     
>>> 2) option to load the vbios from a file specified in guest cfgfile
>>>   
>>>       
>> I don't prefer this. It involves much manual work for users. It's better 
>> to find a general solution which is also easy to use.
>>     
>
>   
>> Regards,
>> Weidong
>>     
>
>   
>>> How does that sound like? 
>>>
>>> -- Pasi
>>>
>>>   
>>>       
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