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| author |   Lu Baolu <baolu.lu@linux.intel.com> | 2019-09-06 14:14:49 +0800 |
|---|---|---|
| committer |   Joerg Roedel <jroedel@suse.de> | 2019-09-11 12:34:29 +0200 |
| commit | e5e04d051979dbd636a99099b7a595093c50a4bc (patch) | |
| tree | 02c641871e285fea720da12bd1420bc865ccae83 /Documentation/admin-guide | |
| parent | swiotlb: Split size parameter to map/unmap APIs (diff) | |
| download | linux-dev-e5e04d051979dbd636a99099b7a595093c50a4bc.tar.xz linux-dev-e5e04d051979dbd636a99099b7a595093c50a4bc.zip | |
iommu/vt-d: Check whether device requires bounce buffer
This adds a helper to check whether a device needs to
use bounce buffer. It also provides a boot time option
to disable the bounce buffer. Users can use this to
prevent the iommu driver from using the bounce buffer
for performance gain.
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Xu Pengfei <pengfei.xu@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 47d981a86e2f..aaca73080097 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1732,6 +1732,11 @@ Note that using this option lowers the security provided by tboot because it makes the system vulnerable to DMA attacks. + nobounce [Default off] + Disable bounce buffer for unstrusted devices such as + the Thunderbolt devices. This will treat the untrusted + devices as the trusted ones, hence might expose security + risks of DMA attacks. intel_idle.max_cstate= [KNL,HW,ACPI,X86] 0 disables intel_idle and fall back on acpi_idle. |