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Logan Gunthorpe
3332364e4e
Non-Transparent Bridge (NTB) devices (among others) may have many DMA
aliases seeing the hardware will send requests with different device ids
depending on their origin across the bridged hardware.
See commit ad281ecf1c ("PCI: Add DMA alias quirk for Microsemi
Switchtec NTB") for more information on this.
The AMD IOMMU ignores all the PCI aliases except the last one so DMA
transfers from these aliases will be blocked on AMD hardware with the
IOMMU enabled.
To fix this, ensure the DTEs are cloned for every PCI alias. This is
done by copying the DTE data for each alias as well as the IVRS alias
every time it is changed.
Signed-off-by: Logan Gunthorpe <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>
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.