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16ecf10e81
When using first-level translation for IOVA, currently the U/S bit in the
page table is cleared which implies DMA requests with user privilege are
blocked. As the result, following error messages might be observed when
passing through a device to user level:
DMAR: DRHD: handling fault status reg 3
DMAR: [DMA Read] Request device [41:00.0] PASID 1 fault addr 7ecdcd000
[fault reason 129] SM: U/S set 0 for first-level translation
with user privilege
This fixes it by setting U/S bit in the first level page table and makes
IOVA over first level compatible with previous second-level translation.
Fixes: b802d070a5 ("iommu/vt-d: Use iova over first level")
Reported-by: Xin Zeng <xin.zeng@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200622231345.29722-3-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.