1What:		/sys/kernel/iommu_groups/
2Date:		May 2012
3KernelVersion:	v3.5
4Contact:	Alex Williamson <alex.williamson@redhat.com>
5Description:	/sys/kernel/iommu_groups/ contains a number of sub-
6		directories, each representing an IOMMU group.  The
7		name of the sub-directory matches the iommu_group_id()
8		for the group, which is an integer value.  Within each
9		subdirectory is another directory named "devices" with
10		links to the sysfs devices contained in this group.
11		The group directory also optionally contains a "name"
12		file if the IOMMU driver has chosen to register a more
13		common name for the group.
14Users:
15
16What:		/sys/kernel/iommu_groups/reserved_regions
17Date: 		January 2017
18KernelVersion:  v4.11
19Contact: 	Eric Auger <eric.auger@redhat.com>
20Description:    /sys/kernel/iommu_groups/reserved_regions list IOVA
21		regions that are reserved. Not necessarily all
22		reserved regions are listed. This is typically used to
23		output direct-mapped, MSI, non mappable regions. Each
24		region is described on a single line: the 1st field is
25		the base IOVA, the second is the end IOVA and the third
26		field describes the type of the region.
27
28What:		/sys/kernel/iommu_groups/reserved_regions
29Date: 		June 2019
30KernelVersion:  v5.3
31Contact: 	Eric Auger <eric.auger@redhat.com>
32Description:    In case an RMRR is used only by graphics or USB devices
33		it is now exposed as "direct-relaxable" instead of "direct".
34		In device assignment use case, for instance, those RMRR
35		are considered to be relaxable and safe.
36