Re: [RFC/RFT] Add noats flag to boot parameters

[Joerg Roedel]

On Sun, Apr 29, 2018 at 09:16:48PM +0300, Gil Kupfer wrote:
> This patch adds noats option to the pci boot parameter.
> When noats is selected, all ATS related functions fail immediately and
> the IOMMU is configured to not use device-iotlb.
> 
> Any function that checks for ATS capabilities directly against the
> devices should also check this flag. (Currently, such functions exist
> only in IOMMU drivers, and they are covered by this patch.)
> 
> The motivation behind this patch is the existence of malicious devices.
> Lots of research has been done about how to utilitize the IOMMU as a
> protection from such devices. When ATS is supported, any I/O device can
> access any physical access by faking device-IOTLB entries.
> Adding the ability to ignore these entries lets sysadmins enhance system
> security.
> 
> Signed-off-by: Gil Kupfer <gilkup@xxxxxxxxxxxxxxxxx>

This has also been on my list, thanks for doing that.

Acked-by: Joerg Roedel <jroedel@xxxxxxx>