1 What: /sys/kernel/iommu_groups/
2 Date: May 2012
3 KernelVersion: v3.5
4 Contact: Alex Williamson <alex.williamso
5 Description: /sys/kernel/iommu_groups/ cont
6 directories, each representing
7 name of the sub-directory matc
8 for the group, which is an int
9 subdirectory is another direct
10 links to the sysfs devices con
11 The group directory also optio
12 file if the IOMMU driver has c
13 common name for the group.
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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