iommu: Add option to group multi-function devices

The option iommu=group_mf indicates the that the iommu driver should
expose all functions of a multi-function PCI device as the same
iommu_device_group.  This is useful for disallowing individual functions
being exposed as independent devices to userspace as there are often
hidden dependencies.  Virtual functions are not affected by this option.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index a0c5c5f4fce6..e1b6e4469845 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1059,7 +1059,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                 nomerge
                 forcesac
                 soft
-                pt      [x86, IA-64]
+                pt              [x86, IA-64]
+                group_mf        [x86, IA-64]
+
 
         io7=            [HW] IO7 for Marvel based alpha systems
                         See comment before marvel_specify_io7 in