mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-09-22 09:34:56 +02:00
Vasant Hegde
a4fb0954f3
[ Upstream commit 58c0ac6125 ]
Due to CVE-2023-20585, the Event log buffer must use the maximum supported
size (512K) on Milan/Genoa (Family 0x19) systems when SNP is enabled,
to mitigate a potential security vulnerability. All other systems continue to
use the default Event log buffer size (8K).
Apply the errata fix by making the following changes:
* Introduce new global variable (amd_iommu_evtlog_size) to have event log
buffer size. Adjust variable size for family 0x19.
* Since 'iommu_snp_enable()' must be called after the core IOMMU subsystem
is initialized, it cannot be moved to the early init stage. The SNP errata
must also be applied after the 'iommu_snp_enable()' check. Therefore,
'alloc_event_buffer()' and 'iommu_enable_event_buffer()' are now called
in the IOMMU_ENABLED state, after the errata is applied.
* Adjust alloc_event_buffer() and iommu_enable_event_buffer() to handle
all IOMMU instances.
* Also rename EVT_* macros to make it more readable.
Link: https://www.amd.com/en/resources/product-security/bulletin/amd-sb-3016.html
Cc: Borislav Petkov <bp@alien8.de>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Tested-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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 reStructuredText 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.