Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 65 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-kernel-iommu_groups b/Documentation/ABI/testing/sysfs-kernel-iommu_groups
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+What:		/sys/kernel/iommu_groups/
+Date:		May 2012
+KernelVersion:	v3.5
+Contact:	Alex Williamson <alex.williamson@redhat.com>
+Description:	/sys/kernel/iommu_groups/ contains a number of sub-
+		directories, each representing an IOMMU group.  The
+		name of the sub-directory matches the iommu_group_id()
+		for the group, which is an integer value.  Within each
+		subdirectory is another directory named "devices" with
+		links to the sysfs devices contained in this group.
+		The group directory also optionally contains a "name"
+		file if the IOMMU driver has chosen to register a more
+		common name for the group.
+Users:
+
+What:		/sys/kernel/iommu_groups/reserved_regions
+Date: 		January 2017
+KernelVersion:  v4.11
+Contact: 	Eric Auger <eric.auger@redhat.com>
+Description:    /sys/kernel/iommu_groups/reserved_regions list IOVA
+		regions that are reserved. Not necessarily all
+		reserved regions are listed. This is typically used to
+		output direct-mapped, MSI, non mappable regions. Each
+		region is described on a single line: the 1st field is
+		the base IOVA, the second is the end IOVA and the third
+		field describes the type of the region.
+
+		Since kernel 5.3, in case an RMRR is used only by graphics or
+		USB devices it is now exposed as "direct-relaxable" instead
+		of "direct". In device assignment use case, for instance,
+		those RMRR are considered to be relaxable and safe.
+
+What:		/sys/kernel/iommu_groups/<grp_id>/type
+Date:		November 2020
+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 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.
+		DMA-FQ    As above, but using batched invalidation to lazily
+		          remove translations after use. This may offer reduced
+			  overhead at the cost of reduced memory protection.
+		identity  All the DMA transactions from the device in this group
+		          are not translated by the iommu. Maximum performance
+			  but zero protection.
+		auto      Change to the type the device was booted with.
+		========  ======================================================
+
+		The default domain type of a group may be modified only when
+
+		- 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
+		need to reboot the machine to get it to normal state). So, it's
+		expected that the users understand what they're doing.