[coreboot] PCI passthrough on ASUS KGPE-D16

Taiidan at gmx.com Taiidan at gmx.com
Thu Oct 6 05:59:05 CEST 2016


I would really love to find a legit answer Re: what chipsets/mobos 
support gfx i/o fwd before I splash out hundreds of dollars.


AFIAK forwarding graphics devices requires a lot more special sauce than 
regular pci devices (like network interfaces)

On my propitiatory-firmware intel laptop dmesg says
"DMAR: BIOS has allocated no shadow GTT; disabling IOMMU for graphics"
So apparently you need a shadow gart for it to work, something that is 
above my paygrade.

It would be really great if there was an IOMMU/GFX bit on the coreboot 
supported motherboards page as this is a common question that never 
finds anything more than anecdotal evidence. I am grateful for your help 
mike but running grep commands on the source files provides nothing more 
than just that.

On 10/03/2016 07:09 PM, Mike Banon wrote:
> Correct me if I am wrong, but I think: IOMMU support means that a
> graphics card passthrough is possible (this is binary: IOMMU yes ==>
> possible / no ==> not possible). If IOMMU support is buggy (which
> seems to be commonly found with proprietary BIOS) maybe your system
> could experience some bugs while you are using this feature. Of course
> the most reliable way to find out is to try it, but I am pretty sure
> that coreboot's IOMMU support is good
>
> On Sun, Oct 2, 2016 at 9:04 PM, Zoran Stojsavljevic
> <zoran.stojsavljevic at gmail.com> wrote:
>>> Would it be possible to passthrough a graphics card to a virtual machine
>>> while using Coreboot/Libreboot?
>> Hello opteron/AMD supporter,
>>
>> You did ask very (very, should say extremely) tricky question, you do know
>> this (I betcha you do, don't you)??? ;-)
>>
>> Zoran
>> _______
>>
>> On Sun, Oct 2, 2016 at 6:22 PM, <opteron at keemail.me> wrote:
>>> Hi,
>>>
>>> would it be possible to passthrough a graphics card to a virtual machine
>>> while using Coreboot/Libreboot? The libreboot website says that the
>>> motherboard offers full IOMMU-support when using a CPU from the Opteron
>>> 6200/6300 series.
>>>
>>> https://wiki.archlinux.org/index.php/PCI_passthrough_via_OVMF
>>> https://libreboot.org/docs/hcl/kgpe-d16.html
>>>
>>> --
>>> coreboot mailing list: coreboot at coreboot.org
>>> https://www.coreboot.org/mailman/listinfo/coreboot
>>
>>
>> --
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>> https://www.coreboot.org/mailman/listinfo/coreboot




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