path: root/Documentation
diff options
authorJoerg Roedel <>2011-12-01 15:49:45 +0100
committerHiroshi DOYU <>2012-01-23 11:11:40 +0200
commitcea9c2d238f5adaae8afa0b20aa5fb91d694c954 (patch)
treee1bffcb47740e98dc9a292ae12c2e9764a909f39 /Documentation
parentf3c7fe5aa2b9ddcfbac4a64335a6139558645fc9 (diff)
iommu/amd: Put IOMMUv2 capable devices in pt_domain
If the device starts to use IOMMUv2 features the dma handles need to stay valid. The only sane way to do this is to use a identity mapping for the device and not translate it by the iommu. This is implemented with this patch. Since this lifts the device-isolation there is also a new kernel parameter which allows to disable that feature. Signed-off-by: Joerg Roedel <>
Diffstat (limited to 'Documentation')
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 69255e88c72b..4d5c56502690 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -315,6 +315,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
is a lot of faster
off - do not initialize any AMD IOMMU found in
the system
+ force_isolation - Force device isolation for all
+ devices. The IOMMU driver is not
+ allowed anymore to lift isolation
+ requirements as needed. This option
+ does not override iommu=pt [HW,JOY] Amiga joystick support
Map of devices attached to JOY0DAT and JOY1DAT