[PATCH v1 0/9] tools/x86/kcpuid: Complete the CPUID database

From: Ahmed S. Darwish
Date: Thu Jul 18 2024 - 09:48:15 EST


Hi,

This patch series enhances the Linux Kernel's kcpuid tool with full
cpuid leaves bitfields coverage through a CSV file generated from:

https://gitlab.com/x86-cpuid.org/x86-cpuid-db

The existing CSV file covers 291 cpuid bitfield entries, while the new
generated one in this patch series covers 835+ entries with full
descriptions.

The new file also covers having the same bitfields' format repeated
across a number of subleaves. This is encountered while enumerating
hierarchical CPU structures like cache, TLB, and CPU topology levels.

The generated file has the following blurb automatically added:

# SPDX-License-Identifier: CC0-1.0
# Generator: x86-cpuid-db v1.0

where the generator tag includes the x86-cpuid-db project's workspace
"git describe" string. This is intended for projects like KernelCI, to
aid in verifying that the generated files have not been tampered with.

There's also a hint for future contributors:

# Auto-generated file
# Please submit all updates and bugfixes to https://x86-cpuid.org

We kindly expect the x86 tree maintainers to guide developers so that
any bugfixes or enhancements to the CSV file are to be submitted
directly to x86-cpuid.org upstream, thus benefiting the whole ecosystem.

Beside reading the actual new CSV file before and after, a nice
demonstration would be to run the command below:

kcpuid --detail --all

and to compare the output accordingly. The differences get even bigger
when running the above on the more featureful x86 CPUs; Xeon and Zen.

The first set of patches in this series are kcpuid bugfixes and
refactorings. Afterwards, cpuid enumeration support for hierarchical CPU
structures is added. Then, the auto-generated CSV file is introduced.

Thanks!

8<-----

Ahmed S. Darwish (9):
tools/x86/kcpuid: Remove unused variable
tools/x86/kcpuid: Properly align long-description columns
tools/x86/kcpuid: Set max possible subleaves count to 64
tools/x86/kcpuid: Protect against faulty "max subleaf" values
tools/x86/kcpuid: Strip bitfield names leading/trailing whitespace
tools/x86/kcpuid: Recognize all leaves with subleaves
tools/x86/kcpuid: Parse subleaf ranges if provided
tools/x86/kcpuid: Introduce a complete cpuid bitfields CSV file
MAINTAINERS: Add x86 cpuid database entry

MAINTAINERS | 10 +
tools/arch/x86/kcpuid/cpuid.csv | 1430 ++++++++++++++++++++++---------
tools/arch/x86/kcpuid/kcpuid.c | 105 +--
3 files changed, 1083 insertions(+), 462 deletions(-)

base-commit: 0c3836482481200ead7b416ca80c68a29cfdaabd
--
2.45.2