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| 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 /drivers/iommu | |
| parent | iommu/vt-d: Refactor Kconfig a bit (diff) | |
| download | linux-dev-792fb43ce2c98878f1539c1d3fdecc1d7a7d78fd.tar.xz linux-dev-792fb43ce2c98878f1539c1d3fdecc1d7a7d78fd.zip | |
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 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/intel/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/iommu/intel/iommu.c | 5 |
2 files changed, 5 insertions, 1 deletions
diff --git a/drivers/iommu/intel/Kconfig b/drivers/iommu/intel/Kconfig index c1a92c3049d0..0ddb77115be7 100644 --- a/drivers/iommu/intel/Kconfig +++ b/drivers/iommu/intel/Kconfig @@ -84,6 +84,7 @@ config INTEL_IOMMU_FLOPPY_WA config INTEL_IOMMU_SCALABLE_MODE_DEFAULT_ON bool "Enable Intel IOMMU scalable mode by default" + default y help Selecting this option will enable by default the scalable mode if hardware presents the capability. The scalable mode is defined in diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index acb91ddf32d0..8c9a9ed7dc09 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -432,8 +432,11 @@ static int __init intel_iommu_setup(char *str) pr_info("Disable supported super page\n"); intel_iommu_superpage = 0; } else if (!strncmp(str, "sm_on", 5)) { - pr_info("Intel-IOMMU: scalable mode supported\n"); + pr_info("Enable scalable mode if hardware supports\n"); intel_iommu_sm = 1; + } else if (!strncmp(str, "sm_off", 6)) { + pr_info("Scalable mode is disallowed\n"); + intel_iommu_sm = 0; } else if (!strncmp(str, "tboot_noforce", 13)) { pr_info("Intel-IOMMU: not forcing on after tboot. This could expose security risk for tboot\n"); intel_iommu_tboot_noforce = 1; |