1 What: /sys/kernel/iommu_groups/ 1 What: /sys/kernel/iommu_groups/
2 Date: May 2012 2 Date: May 2012
3 KernelVersion: v3.5 3 KernelVersion: v3.5
4 Contact: Alex Williamson <alex.williamso 4 Contact: Alex Williamson <alex.williamson@redhat.com>
5 Description: /sys/kernel/iommu_groups/ cont 5 Description: /sys/kernel/iommu_groups/ contains a number of sub-
6 directories, each representing 6 directories, each representing an IOMMU group. The
7 name of the sub-directory matc 7 name of the sub-directory matches the iommu_group_id()
8 for the group, which is an int 8 for the group, which is an integer value. Within each
9 subdirectory is another direct 9 subdirectory is another directory named "devices" with
10 links to the sysfs devices con 10 links to the sysfs devices contained in this group.
11 The group directory also optio 11 The group directory also optionally contains a "name"
12 file if the IOMMU driver has c 12 file if the IOMMU driver has chosen to register a more
13 common name for the group. 13 common name for the group.
14 Users: 14 Users:
15 <<
16 What: /sys/kernel/iommu_groups/reser <<
17 Date: January 2017 <<
18 KernelVersion: v4.11 <<
19 Contact: Eric Auger <eric.auger@redhat.c <<
20 Description: /sys/kernel/iommu_groups/reser <<
21 regions that are reserved. Not <<
22 reserved regions are listed. T <<
23 output direct-mapped, MSI, non <<
24 region is described on a singl <<
25 the base IOVA, the second is t <<
26 field describes the type of th <<
27 <<
28 Since kernel 5.3, in case an R <<
29 USB devices it is now exposed <<
30 of "direct". In device assignm <<
31 those RMRR are considered to b <<
32 <<
33 What: /sys/kernel/iommu_groups/<grp_ <<
34 Date: November 2020 <<
35 KernelVersion: v5.11 <<
36 Contact: Sai Praneeth Prakhya <sai.prane <<
37 Description: /sys/kernel/iommu_groups/<grp_ <<
38 domain in use by iommu for thi <<
39 for possible read values. A pr <<
40 change the group type by writi <<
41 <<
42 ======== ==================== <<
43 DMA All the DMA transact <<
44 are translated by th <<
45 DMA-FQ As above, but using <<
46 remove translations <<
47 overhead at the cost <<
48 identity All the DMA transact <<
49 are not translated b <<
50 but zero protection. <<
51 auto Change to the type t <<
52 ======== ==================== <<
53 <<
54 The default domain type of a g <<
55 <<
56 - The device in the group is n <<
57 So, the users must unbind th <<
58 changing the default domain <<
59 <<
60 Unbinding a device driver will <<
61 over the device and if done on <<
62 system could lead to catastrop <<
63 need to reboot the machine to <<
64 expected that the users unders <<
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