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authorLinus Torvalds <torvalds@linux-foundation.org>2023-11-04 08:46:37 -1000
committerLinus Torvalds <torvalds@linux-foundation.org>2023-11-04 08:46:37 -1000
commit0a23fb262d17f587c9bb1e6cc83ad4158b21f16e (patch)
treefd5a2b1563856a04fa056daa18cca7be8896b322 /Documentation
parent5c5e048b2417a56b7b52bdbb66d4fc99d0c20dd2 (diff)
parentcf5ab01c87030a085e211a0a327535932ec6f719 (diff)
Merge tag 'x86_microcode_for_v6.7_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 microcode loading updates from Borislac Petkov: "Major microcode loader restructuring, cleanup and improvements by Thomas Gleixner: - Restructure the code needed for it and add a temporary initrd mapping on 32-bit so that the loader can access the microcode blobs. This in itself is a preparation for the next major improvement: - Do not load microcode on 32-bit before paging has been enabled. Handling this has caused an endless stream of headaches, issues, ugly code and unnecessary hacks in the past. And there really wasn't any sensible reason to do that in the first place. So switch the 32-bit loading to happen after paging has been enabled and turn the loader code "real purrty" again - Drop mixed microcode steppings loading on Intel - there, a single patch loaded on the whole system is sufficient - Rework late loading to track which CPUs have updated microcode successfully and which haven't, act accordingly - Move late microcode loading on Intel in NMI context in order to guarantee concurrent loading on all threads - Make the late loading CPU-hotplug-safe and have the offlined threads be woken up for the purpose of the update - Add support for a minimum revision which determines whether late microcode loading is safe on a machine and the microcode does not change software visible features which the machine cannot use anyway since feature detection has happened already. Roughly, the minimum revision is the smallest revision number which must be loaded currently on the system so that late updates can be allowed - Other nice leanups, fixess, etc all over the place" * tag 'x86_microcode_for_v6.7_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) x86/microcode/intel: Add a minimum required revision for late loading x86/microcode: Prepare for minimal revision check x86/microcode: Handle "offline" CPUs correctly x86/apic: Provide apic_force_nmi_on_cpu() x86/microcode: Protect against instrumentation x86/microcode: Rendezvous and load in NMI x86/microcode: Replace the all-in-one rendevous handler x86/microcode: Provide new control functions x86/microcode: Add per CPU control field x86/microcode: Add per CPU result state x86/microcode: Sanitize __wait_for_cpus() x86/microcode: Clarify the late load logic x86/microcode: Handle "nosmt" correctly x86/microcode: Clean up mc_cpu_down_prep() x86/microcode: Get rid of the schedule work indirection x86/microcode: Mop up early loading leftovers x86/microcode/amd: Use cached microcode for AP load x86/microcode/amd: Cache builtin/initrd microcode early x86/microcode/amd: Cache builtin microcode too x86/microcode/amd: Use correct per CPU ucode_cpu_info ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt5
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 01c7082ee999..2a4bc78c27ec 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3333,6 +3333,11 @@
mga= [HW,DRM]
+ microcode.force_minrev= [X86]
+ Format: <bool>
+ Enable or disable the microcode minimal revision
+ enforcement for the runtime microcode loader.
+
min_addr=nn[KMG] [KNL,BOOT,IA-64] All physical memory below this
physical address is ignored.