[coreboot] Thinkpad SD card controller DMA

Nico Huber nico.h at gmx.de
Fri Jun 22 19:29:07 CEST 2018


Hi Thomas,

On 21.06.2018 22:33, Thomasheidler wrote:
> Sounds like disabling the PCIe port of the device is the safest
> solution. Will switching the value in the devicetree be enough or is
> that too uncertain?

I think, I already answered that but you lost the quote:

>> If you want to be sure, find research (for exactly your platform) that
>> confirms that a given method prevents DMA; or, get a programmable PCIe
>> device and test it yourself. There are no shortcuts.

Also worth to mention: the settings in the devicetree might only hide
the PCIe port and the downstream device. Depending on your OS and the
way it handles the IOMMU, that could also make things worse; e.g. the OS
might only enable the IOMMU for devices it can see.

Nico

PS. Please, if you reply to an email, quote the part that you reply to,
    write your reply below the quote, make sure that your reply makes
    sense in the context of the quote.



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