Commits
Gil Kupfer committed cef74409ea7
PCI: Add "pci=noats" boot parameter Adds a "pci=noats" boot parameter. When supplied, 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 use the IOMMU as protection from such devices. When ATS is supported, any I/O device can access any physical address by faking device-IOTLB entries. Adding the ability to ignore these entries lets sysadmins enhance system security. Signed-off-by: Gil Kupfer <gilkup@cs.technion.ac.il> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Joerg Roedel <jroedel@suse.de>