diff options
| author | Lu Baolu <baolu.lu@linux.intel.com> | 2021-08-18 21:48:47 +0800 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2021-08-19 10:41:08 +0200 |
| commit | 792fb43ce2c98878f1539c1d3fdecc1d7a7d78fd (patch) | |
| tree | f2a9e8aa1379f84db4d2bb636e5f591529c166d6 /Documentation/admin-guide/kernel-parameters.txt | |
| parent | 01dac2d9d2364d2a68b37cc1381947ca53413b51 (diff) | |
iommu/vt-d: Enable Intel IOMMU scalable mode by default
The commit 8950dcd83ae7d ("iommu/vt-d: Leave scalable mode default off")
leaves the scalable mode default off and end users could turn it on with
"intel_iommu=sm_on". Using the Intel IOMMU scalable mode for kernel DMA,
user-level device access and Shared Virtual Address have been enabled.
This enables the scalable mode by default if the hardware advertises the
support and adds kernel options of "intel_iommu=sm_on/sm_off" for end
users to configure it through the kernel parameters.
Suggested-by: Ashok Raj <ashok.raj@intel.com>
Suggested-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20210720013856.4143880-1-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/r/20210818134852.1847070-5-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 19192b39952a..87d46cb76121 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1946,11 +1946,12 @@ By default, super page will be supported if Intel IOMMU has the capability. With this option, super page will not be supported. - sm_on [Default Off] - By default, scalable mode will be disabled even if the - hardware advertises that it has support for the scalable - mode translation. With this option set, scalable mode - will be used on hardware which claims to support it. + sm_on + Enable the Intel IOMMU scalable mode if the hardware + advertises that it has support for the scalable mode + translation. + sm_off + Disallow use of the Intel IOMMU scalable mode. tboot_noforce [Default Off] Do not force the Intel IOMMU enabled under tboot. By default, tboot will force Intel IOMMU on, which |