Re: [PATCH] iommu/intel: disable DMAR for Q35 integrated gfx

[Kees Cook]

On Mon, Dec 5, 2016 at 2:47 PM, David Woodhouse <dwmw2@xxxxxxxxxxxxx> wrote:
> On Mon, 2016-12-05 at 14:18 -0800, Kees Cook wrote:
>> Hm, I have no idea. :) What would I look for in the BIOS?
>
> For a start, what is the actual failure mode?

Based on initial testing (not that I've spent tons of time with it,
since I need that machine running): at graphics init, entire system
hangs. :P

>> I figured since g4 was busted, surely q35 was too, since it's even
>> older...
>
> Oh no, they all have different failures. Intel never actually *tested*
> their graphics hardware before shipping it, but IIRC it was only Q4x
> where we concluded the hardware was just too broken to live.

Wheee!

-Kees

-- 
Kees Cook
Nexus Security