387caf0b75
Some buggy BIOSes might define multiple exclusion ranges of the IVMD entries which are associated with the same IOMMU hardware. This leads to the overwritten exclusion range (exclusion_start and exclusion_length members) in set_device_exclusion_range(). Here is a real case: When attaching two Broadcom RAID controllers to a server, the first one reports the failure during booting (the disks connecting to the RAID controller cannot be detected). This patch prevents the issue by treating per-device exclusion ranges as r/w unity-mapped regions. Discussion: * https://lists.linuxfoundation.org/pipermail/iommu/2019-November/040140.html Suggested-by: Joerg Roedel <joro@8bytes.org> Signed-off-by: Adrian Huang <ahuang12@lenovo.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.