[PATCH v5 0/7] x86: Support for Intel Microcode Staging Feature

From: Chang S. Bae
Date: Sat Aug 23 2025 - 11:52:28 EST


Hi all,

This is another iteration -- changes since v4 [*]:

* Reworked the preparatory change before referencing
cpu_primary_thread_mask, based on Dave’s feedback. This is now patch1.

* Incorporated further feedback from Dave on the staging code, mainly
to improve clarity, reduce ambiguity, and fix minor issues. Each
patch includes some details.

* Collected Chao’s review tag (thanks!) for the first and last patches.

As usual, the series is also available here:
git://github.com/intel-staging/microcode.git staging_v5

[*] https://lore.kernel.org/lkml/20250813172649.15474-1-chang.seok.bae@xxxxxxxxx/

Thanks,
Chang

Chang S. Bae (7):
x86/cpu/topology: Make primary thread mask available with SMP=n
x86/microcode: Introduce staging step to reduce late-loading time
x86/microcode/intel: Establish staging control logic
x86/microcode/intel: Define staging state struct
x86/microcode/intel: Implement staging handler
x86/microcode/intel: Support mailbox transfer
x86/microcode/intel: Enable staging when available

arch/x86/include/asm/msr-index.h | 9 +
arch/x86/include/asm/topology.h | 12 +-
arch/x86/kernel/cpu/microcode/core.c | 11 +
arch/x86/kernel/cpu/microcode/intel.c | 386 +++++++++++++++++++++++
arch/x86/kernel/cpu/microcode/internal.h | 4 +-
arch/x86/kernel/cpu/topology.c | 4 -
arch/x86/kernel/cpu/topology_common.c | 3 +
arch/x86/kernel/smpboot.c | 3 -
8 files changed, 418 insertions(+), 14 deletions(-)


base-commit: 7182bf4176f93be42225d2ef983894febfa4a1b1
--
2.48.1