This is a note to let you know that I've just added the patch titled
x86/CPU: Add a microcode loader callback
to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-cpu-add-a-microcode-loader-callback.patch
and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1008c52c09dcb23d93f8e0ea83a6246265d2cce0 Mon Sep 17 00:00:00 2001
From: Borislav Petkov <bp@xxxxxxx>
Date: Fri, 16 Feb 2018 12:26:39 +0100
Subject: x86/CPU: Add a microcode loader callback
From: Borislav Petkov <bp@xxxxxxx>
commit 1008c52c09dcb23d93f8e0ea83a6246265d2cce0 upstream.
Add a callback function which the microcode loader calls when microcode
has been updated to a newer revision. Do the callback only when no error
was encountered during loading.
Tested-by: Ashok Raj <ashok.raj@xxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Ashok Raj <ashok.raj@xxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20180216112640.11554-3-bp@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/processor.h | 1 +
arch/x86/kernel/cpu/common.c | 10 ++++++++++
arch/x86/kernel/cpu/microcode/core.c | 8 ++++++--
3 files changed, 17 insertions(+), 2 deletions(-)
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -969,4 +969,5 @@ bool xen_set_default_idle(void);
void stop_this_cpu(void *dummy);
void df_debug(struct pt_regs *regs, long error_code);
+void microcode_check(void);
#endif /* _ASM_X86_PROCESSOR_H */
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1749,3 +1749,13 @@ static int __init init_cpu_syscore(void)
return 0;
}
core_initcall(init_cpu_syscore);
+
+/*
+ * The microcode loader calls this upon late microcode load to recheck features,
+ * only when microcode has been updated. Caller holds microcode_mutex and CPU
+ * hotplug lock.
+ */
+void microcode_check(void)
+{
+ perf_check_microcode();
+}
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -509,6 +509,7 @@ static ssize_t reload_store(struct devic
const char *buf, size_t size)
{
enum ucode_state tmp_ret = UCODE_OK;
+ bool do_callback = false;
unsigned long val;
ssize_t ret = 0;
int cpu;
@@ -531,10 +532,13 @@ static ssize_t reload_store(struct devic
if (!ret)
ret = -EINVAL;
}
+
+ if (tmp_ret == UCODE_UPDATED)
+ do_callback = true;
}
- if (!ret && tmp_ret == UCODE_UPDATED)
- perf_check_microcode();
+ if (!ret && do_callback)
+ microcode_check();
mutex_unlock(µcode_mutex);
put_online_cpus();
Patches currently in stable-queue which might be from bp@xxxxxxx are
queue-4.15/x86-microcode-intel-check-microcode-revision-before-updating-sibling-threads.patch
queue-4.15/x86-microcode-attempt-late-loading-only-when-new-microcode-is-present.patch
queue-4.15/x86-microcode-propagate-return-value-from-updating-functions.patch
queue-4.15/x86-cpu-check-cpu-feature-bits-after-microcode-upgrade.patch
queue-4.15/x86-microcode-intel-writeback-and-invalidate-caches-before-updating-microcode.patch
queue-4.15/x86-microcode-intel-look-into-the-patch-cache-first.patch
queue-4.15/edac-mv64x60-fix-an-error-handling-path.patch
queue-4.15/x86-microcode-request-microcode-on-the-bsp.patch
queue-4.15/x86-microcode-get-rid-of-struct-apply_microcode_ctx.patch
queue-4.15/x86-microcode-fix-cpu-synchronization-routine.patch
queue-4.15/x86-microcode-synchronize-late-microcode-loading.patch
queue-4.15/x86-microcode-do-not-upload-microcode-if-cpus-are-offline.patch
queue-4.15/x86-cpu-add-a-microcode-loader-callback.patch