Files
linux-stable-mirror/scripts/update-intel-ucode-defs.py
Sohil Mehta 00e05495c5 scripts/x86/intel: Add a script to update the old microcode list
The kernel maintains a table of minimum expected microcode revisions for
Intel CPUs in intel-ucode-defs.h. Systems with microcode older than
these revisions are flagged with X86_BUG_OLD_MICROCODE.

The static list of microcode revisions needs to be updated periodically
in response to releases of the official microcode at:
https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files.git.

Introduce a simple script to extract the revision information from the
microcode files and print it in the precise format expected by the
microcode header.

Maintaining the script in the kernel tree ensures a central location
that a submitter can use to generate the kernel-specific update. This
not only reduces the possibility of errors but also makes it easier to
validate the changes for reviewers and maintainers.

Typically, someone at Intel would see a new public release, wait for at
least three months to ensure the update is stable, run this script to
refresh the intel-ucode-defs.h file, and send a patch upstream to update
the mainline and stable versions.

Having a standard update script and a defined process minimizes the
ambiguity when refreshing the old microcode list. As always, there can
be exceptions to this process which should be supported with appropriate
justification.

Originally-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Sohil Mehta <sohil.mehta@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://patch.msgid.link/20260407014226.1169040-3-sohil.mehta@intel.com
2026-04-29 15:53:19 -07:00

131 lines
4.1 KiB
Python
Executable File

#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-2.0
import argparse
import re
import shutil
import subprocess
import sys
import os
script = os.path.relpath(__file__)
DESCRIPTION = f"""
For Intel CPUs, update the microcode revisions that determine
X86_BUG_OLD_MICROCODE.
This script is intended to be run in response to releases of the
official Intel microcode GitHub repository:
https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files.git
It takes the Intel microcode files as input and uses iucode-tool to
extract the revision information. It prints the output in the format
expected by intel-ucode-defs.h.
Usage:
./{script} /path/to/microcode/files > /path/to/intel-ucode-defs.h
Typically, someone at Intel would see a new public release, wait for at
least three months to ensure the update is stable, run this script to
refresh the intel-ucode-defs.h file, and send a patch upstream to update
the mainline and stable versions.
Any exception to this process should be supported with an appropriate
justification.
"""
SIG_RE = re.compile(r'sig (0x[0-9a-fA-F]+)')
PFM_RE = re.compile(r'pf_mask (0x[0-9a-fA-F]+)')
REV_RE = re.compile(r'rev (0x[0-9a-fA-F]+)')
# Functions to extract family, model, and stepping
def bits(val, bottom, top):
mask = (1 << (top + 1 - bottom)) - 1
return (val >> bottom) & mask
def family(sig):
if bits(sig, 8, 11) == 0xf:
return bits(sig, 8, 11) + bits(sig, 20, 27)
return bits(sig, 8, 11)
def model(sig):
return bits(sig, 4, 7) | (bits(sig, 16, 19) << 4)
def step(sig):
return bits(sig, 0, 3)
class Ucode:
def __init__(self, sig, pfm, rev):
self.family = family(sig)
self.model = model(sig)
self.steppings = 1 << step(sig)
self.platforms = pfm
self.rev = rev
self.key = (self.family, self.model, self.steppings, self.platforms)
def __eq__(self, other):
return self.key == other.key
def __hash__(self):
return hash(self.key)
def __str__(self):
return "{ .flags = X86_CPU_ID_FLAG_ENTRY_VALID, .vendor = X86_VENDOR_INTEL, .family = 0x%x, .model = 0x%02x, .steppings = 0x%04x, .platform_mask = 0x%02x, .driver_data = 0x%x }," % \
(self.family, self.model, self.steppings, self.platforms, self.rev)
def main():
parser = argparse.ArgumentParser(description=DESCRIPTION,
formatter_class=argparse.RawDescriptionHelpFormatter)
parser.add_argument('ucode_files', nargs='+', help='Path(s) to the microcode files')
args = parser.parse_args()
# Process the microcode files using iucode-tool
iucode_tool = shutil.which("iucode-tool") or shutil.which("iucode_tool")
if iucode_tool is None:
print("Error: iucode-tool not found, please install it", file=sys.stderr)
sys.exit(1)
cmd = [iucode_tool, '--list-all'] + args.ucode_files
result = subprocess.run(cmd, capture_output=True, text=True)
if result.returncode != 0:
print("Error: iucode-tool ran into an error, exiting", file=sys.stderr)
if result.stderr:
print(result.stderr, file=sys.stderr, end='')
sys.exit(1)
ucodes = set()
# Parse the output of iucode-tool
for line in result.stdout.splitlines():
sig_match = SIG_RE.search(line)
pfm_match = PFM_RE.search(line)
rev_match = REV_RE.search(line)
if not (sig_match and pfm_match and rev_match):
continue
sig = int(sig_match.group(1), 16)
pfm = int(pfm_match.group(1), 16)
rev = int(rev_match.group(1), 16)
debug_rev = bits(rev, 31, 31)
if debug_rev != 0:
print("Error: Debug ucode file found, exiting", file=sys.stderr)
sys.exit(1)
ucodes.add(Ucode(sig, pfm, rev))
if not ucodes:
print("Error: No valid microcode files found, exiting", file=sys.stderr)
sys.exit(1)
# Sort and print the microcode entries
print("/* SPDX-License-Identifier: GPL-2.0 */")
print("/* Auto-generated by scripts/update-intel-ucode-defs.py */")
for u in sorted(ucodes, key=lambda x: x.key):
print(u)
if __name__ == "__main__":
main()