1*4882a593SmuzhiyunWhat: /sys/kernel/iommu_groups/ 2*4882a593SmuzhiyunDate: May 2012 3*4882a593SmuzhiyunKernelVersion: v3.5 4*4882a593SmuzhiyunContact: Alex Williamson <alex.williamson@redhat.com> 5*4882a593SmuzhiyunDescription: /sys/kernel/iommu_groups/ contains a number of sub- 6*4882a593Smuzhiyun directories, each representing an IOMMU group. The 7*4882a593Smuzhiyun name of the sub-directory matches the iommu_group_id() 8*4882a593Smuzhiyun for the group, which is an integer value. Within each 9*4882a593Smuzhiyun subdirectory is another directory named "devices" with 10*4882a593Smuzhiyun links to the sysfs devices contained in this group. 11*4882a593Smuzhiyun The group directory also optionally contains a "name" 12*4882a593Smuzhiyun file if the IOMMU driver has chosen to register a more 13*4882a593Smuzhiyun common name for the group. 14*4882a593SmuzhiyunUsers: 15*4882a593Smuzhiyun 16*4882a593SmuzhiyunWhat: /sys/kernel/iommu_groups/reserved_regions 17*4882a593SmuzhiyunDate: January 2017 18*4882a593SmuzhiyunKernelVersion: v4.11 19*4882a593SmuzhiyunContact: Eric Auger <eric.auger@redhat.com> 20*4882a593SmuzhiyunDescription: /sys/kernel/iommu_groups/reserved_regions list IOVA 21*4882a593Smuzhiyun regions that are reserved. Not necessarily all 22*4882a593Smuzhiyun reserved regions are listed. This is typically used to 23*4882a593Smuzhiyun output direct-mapped, MSI, non mappable regions. Each 24*4882a593Smuzhiyun region is described on a single line: the 1st field is 25*4882a593Smuzhiyun the base IOVA, the second is the end IOVA and the third 26*4882a593Smuzhiyun field describes the type of the region. 27*4882a593Smuzhiyun 28*4882a593SmuzhiyunWhat: /sys/kernel/iommu_groups/reserved_regions 29*4882a593SmuzhiyunDate: June 2019 30*4882a593SmuzhiyunKernelVersion: v5.3 31*4882a593SmuzhiyunContact: Eric Auger <eric.auger@redhat.com> 32*4882a593SmuzhiyunDescription: In case an RMRR is used only by graphics or USB devices 33*4882a593Smuzhiyun it is now exposed as "direct-relaxable" instead of "direct". 34*4882a593Smuzhiyun In device assignment use case, for instance, those RMRR 35*4882a593Smuzhiyun are considered to be relaxable and safe. 36