Ubuntu
linux package

  1. Bug #1820153
  2. Comment #0

Comment 0 for bug 1820153

Revision history for this message
AaronMa (mapengyu) wrote :

SRU justification:

[Impact]
OS can use IOMMU to defend against DMA attacks from a PCI device like thunderbolt one.
Intel adds DMA_CTRL_PLATFORM_OPT_IN_FLAG flag in DMAR ACPI table.
Use this flag to enable IOMMU and use _DSD to identify untrusted PCI devices.

[Fix]
Enable IOMMU when BIOS supports DMA opt in flag and ExternalFacingPort in _DSD.
Disable ATS on the untrusted PCI device.

[Test]
Tested on 2 Intel platforms that supports DMA opt in flag with a thunderbolt dock station.
iommu enabled as expected with this fix.

[Regression Potential]
Upstream fix, Verified on supported platforms, no affection on not supported platforms.
Backported changes are fairly minimal.

These patches are included in 5.0 kernel, disco is good.