This is a note to let you know that I've just added the patch titled
x86/cpufeature: Move processor tracing out of scattered features
to the 4.9-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-cpufeature-move-processor-tracing-out-of-scattered-features.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4fdec2034b7540dda461c6ba33325dfcff345c64 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Date: Tue, 16 Jan 2018 16:42:25 +0100
Subject: x86/cpufeature: Move processor tracing out of scattered features
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From: Paolo Bonzini <pbonzini@xxxxxxxxxx>
commit 4fdec2034b7540dda461c6ba33325dfcff345c64 upstream.
Processor tracing is already enumerated in word 9 (CPUID[7,0].EBX),
so do not duplicate it in the scattered features word.
Besides being more tidy, this will be useful for KVM when it presents
processor tracing to the guests. KVM selects host features that are
supported by both the host kernel (depending on command line options,
CPU errata, or whatever) and KVM. Whenever a full feature word exists,
KVM's code is written in the expectation that the CPUID bit number
matches the X86_FEATURE_* bit number, but this is not the case for
X86_FEATURE_INTEL_PT.
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Luwei Kang <luwei.kang@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1516117345-34561-1-git-send-email-pbonzini@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/cpufeatures.h | 2 +-
arch/x86/kernel/cpu/scattered.c | 1 -
2 files changed, 1 insertion(+), 2 deletions(-)
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -197,7 +197,6 @@
#define X86_FEATURE_RETPOLINE ( 7*32+12) /* Generic Retpoline mitigation for Spectre variant 2 */
#define X86_FEATURE_RETPOLINE_AMD ( 7*32+13) /* AMD Retpoline mitigation for Spectre variant 2 */
-#define X86_FEATURE_INTEL_PT ( 7*32+15) /* Intel Processor Trace */
#define X86_FEATURE_AVX512_4VNNIW (7*32+16) /* AVX-512 Neural Network Instructions */
#define X86_FEATURE_AVX512_4FMAPS (7*32+17) /* AVX-512 Multiply Accumulation Single precision */
#define X86_FEATURE_RSB_CTXSW ( 7*32+19) /* Fill RSB on context switches */
@@ -236,6 +235,7 @@
#define X86_FEATURE_SMAP ( 9*32+20) /* Supervisor Mode Access Prevention */
#define X86_FEATURE_CLFLUSHOPT ( 9*32+23) /* CLFLUSHOPT instruction */
#define X86_FEATURE_CLWB ( 9*32+24) /* CLWB instruction */
+#define X86_FEATURE_INTEL_PT ( 9*32+25) /* Intel Processor Trace */
#define X86_FEATURE_AVX512PF ( 9*32+26) /* AVX-512 Prefetch */
#define X86_FEATURE_AVX512ER ( 9*32+27) /* AVX-512 Exponential and Reciprocal */
#define X86_FEATURE_AVX512CD ( 9*32+28) /* AVX-512 Conflict Detection */
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -31,7 +31,6 @@ void init_scattered_cpuid_features(struc
const struct cpuid_bit *cb;
static const struct cpuid_bit cpuid_bits[] = {
- { X86_FEATURE_INTEL_PT, CR_EBX,25, 0x00000007, 0 },
{ X86_FEATURE_AVX512_4VNNIW, CR_EDX, 2, 0x00000007, 0 },
{ X86_FEATURE_AVX512_4FMAPS, CR_EDX, 3, 0x00000007, 0 },
{ X86_FEATURE_APERFMPERF, CR_ECX, 0, 0x00000006, 0 },
Patches currently in stable-queue which might be from pbonzini@xxxxxxxxxx are
queue-4.9/x86-cpufeature-move-processor-tracing-out-of-scattered-features.patch