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authorAlex Williamson <alex.williamson@redhat.com>2014-06-12 16:12:24 -0600
committerJoerg Roedel <jroedel@suse.de>2014-07-04 12:35:59 +0200
commitc61959ecbbc6bf9034e65c8e8ef03fa9d1066f05 (patch)
tree8c5b068f79d1a873d55d6f00e1888f559e6d1ea4 /Documentation/ABI/testing/sysfs-class-iommu
parentfd2852d5da67ca890b10468e33c68544e8da1ece (diff)
iommu: Add sysfs support for IOMMUs
IOMMUs currently have no common representation to userspace, most seem to have no representation at all aside from a few printks on bootup. There are however features of IOMMUs that are useful to know about. For instance the IOMMU might support superpages, making use of processor large/huge pages more important in a device assignment scenario. It's also useful to create cross links between devices and IOMMU hardware units, so that users might be able to load balance their devices to avoid thrashing a single hardware unit. This patch adds a device create and destroy interface as well as device linking, making it very lightweight for an IOMMU driver to add basic support. IOMMU drivers can provide additional attributes automatically by using an attribute_group. The attributes exposed are expected to be relatively device specific, the means to retrieve them certainly are, so there are currently no common attributes for the new class created here. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-class-iommu')
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1 files changed, 17 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-iommu b/Documentation/ABI/testing/sysfs-class-iommu
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+What: /sys/class/iommu/<iommu>/devices/
+Date: June 2014
+KernelVersion: 3.17
+Contact: Alex Williamson <alex.williamson@redhat.com>
+Description:
+ IOMMU drivers are able to link devices managed by a
+ given IOMMU here to allow association of IOMMU to
+ device.
+
+What: /sys/devices/.../iommu
+Date: June 2014
+KernelVersion: 3.17
+Contact: Alex Williamson <alex.williamson@redhat.com>
+Description:
+ IOMMU drivers are able to link the IOMMU for a
+ given device here to allow association of device to
+ IOMMU.