diff options
Diffstat (limited to 'Documentation/ABI/testing/sysfs-kernel-iommu_groups')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-kernel-iommu_groups | 33 |
1 files changed, 17 insertions, 16 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-iommu_groups b/Documentation/ABI/testing/sysfs-kernel-iommu_groups index 407b1628d7fd..0fedbb0f94e4 100644 --- a/Documentation/ABI/testing/sysfs-kernel-iommu_groups +++ b/Documentation/ABI/testing/sysfs-kernel-iommu_groups @@ -40,23 +40,24 @@ KernelVersion: v5.11 Contact: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Description: /sys/kernel/iommu_groups/<grp_id>/type shows the type of default domain in use by iommu for this group. See include/linux/iommu.h - for possible values. A privileged user could request kernel to - change the group type by writing to this file. Presently, only - three types of request are supported: - 1. DMA: All the DMA transactions from the device in this group - are translated by the iommu. - 2. identity: All the DMA transactions from the device in this - group are *not* translated by the iommu. - 3. auto: Change to the type the device was booted with. - Note: - ----- + for possible read values. A privileged user could request kernel to + change the group type by writing to this file. Valid write values: + + ======== ====================================================== + DMA All the DMA transactions from the device in this group + are translated by the iommu. + identity All the DMA transactions from the device in this group + are not translated by the iommu. + auto Change to the type the device was booted with. + ======== ====================================================== + The default domain type of a group may be modified only when - 1. The group has *only* one device - 2. The device in the group is not bound to any device driver. - So, the users must unbind the appropriate driver before - changing the default domain type. - Caution: - -------- + + - The group has only one device. + - The device in the group is not bound to any device driver. + So, the users must unbind the appropriate driver before + changing the default domain type. + Unbinding a device driver will take away the driver's control over the device and if done on devices that host root file system could lead to catastrophic effects (the users might |