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| author | Robin Murphy <robin.murphy@arm.com> | 2021-06-14 15:57:26 +0100 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2021-06-17 17:03:46 +0200 |
| commit | 531353e650db087e61ce84f8e6b7e0982c1dc1b0 (patch) | |
| tree | d74d2237a37ebcf65c20cba8141932442463399c | |
| parent | e86b041ffeff554c9458882ebabc2aba5c864186 (diff) | |
| download | linux-531353e650db087e61ce84f8e6b7e0982c1dc1b0.tar.gz | |
iommu: Update "iommu.strict" documentation
Consolidating the flush queue logic also meant that the "iommu.strict"
option started taking effect on x86 as well. Make sure we document that.
Fixes: a250c23f15c2 ("iommu: remove DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/2c8c06e1b449d6b060c5bf9ad3b403cd142f405d.1623682646.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index cb89dbdedc46..20a32de990ed 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1987,7 +1987,7 @@ forcing Dual Address Cycle for PCI cards supporting greater than 32-bit addressing. - iommu.strict= [ARM64] Configure TLB invalidation behaviour + iommu.strict= [ARM64, X86] Configure TLB invalidation behaviour Format: { "0" | "1" } 0 - Lazy mode. Request that DMA unmap operations use deferred @@ -1998,6 +1998,10 @@ 1 - Strict mode (default). DMA unmap operations invalidate IOMMU hardware TLBs synchronously. + Note: on x86, the default behaviour depends on the + equivalent driver-specific parameters, but a strict + mode explicitly specified by either method takes + precedence. iommu.passthrough= [ARM64, X86] Configure DMA to bypass the IOMMU by default. |