[justincormack]

SATA is not as straightforward, as far as I know there are no known attacks. It depends very much on the intface design, and you do not just get a pcie bus from sata. USB has some weak attacks apparently. Firewire and so on are mulimaster which is much more dangerous. No reason not to use iommu.

[Sanddancer]

SATA devices wouldn't be able to pull these off, but a malicious SATA /controller/, connected to the pci-e bus, could. There have been proof of concept rootkits ( http://www.livehacking.com/2010/11/23/backdoor-rootkit-for-n... ) which hack the firmware of devices to use the negotiated DMA channel for operating system corruption. I used SATA as an example because it's something that would not be as easy to disable. The firewire attack is easy to disable because it's well known and most people don't need firewire. SATA controllers are a lot more common and would require a lot more work to clean up.