[PATCH 1/1 fyi] tools arch x86: Sync the msr-index.h copy with the kernel sources

From: Arnaldo Carvalho de Melo
Date: Tue Dec 20 2022 - 12:35:48 EST


tldr; Just FYI, I'm carrying this on the perf tools tree.

- Arnaldo

Full explanation:

There used to be no copies, with tools/ code using kernel headers
directly. From time to time tools/perf/ broke due to legitimate kernel
hacking. At some point Linus complained about such direct usage. Then we
adopted the current model.

The way these headers are used in perf are not restricted to just
including them to compile something.

There are sometimes used in scripts that convert defines into string
tables, etc, so some change may break one of these scripts, or new MSRs
may use some different #define pattern, etc.

E.g.:

$ ls -1 tools/perf/trace/beauty/*.sh | head -5
tools/perf/trace/beauty/arch_errno_names.sh
tools/perf/trace/beauty/drm_ioctl.sh
tools/perf/trace/beauty/fadvise.sh
tools/perf/trace/beauty/fsconfig.sh
tools/perf/trace/beauty/fsmount.sh
$
$ tools/perf/trace/beauty/fadvise.sh
static const char *fadvise_advices[] = {
[0] = "NORMAL",
[1] = "RANDOM",
[2] = "SEQUENTIAL",
[3] = "WILLNEED",
[4] = "DONTNEED",
[5] = "NOREUSE",
};
$

The tools/perf/check-headers.sh script, part of the tools/ build
process, points out changes in the original files.

So its important not to touch the copies in tools/ when doing changes in
the original kernel headers, that will be done later, when
check-headers.sh inform about the change to the perf tools hackers.

---

To pick up the changes in:

97fa21f65c3eb5bb ("x86/resctrl: Move MSR defines into msr-index.h")
7420ae3bb977b46e ("x86/intel_epb: Set Alder Lake N and Raptor Lake P normal EPB")

Addressing these tools/perf build warnings:

diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h
Warning: Kernel ABI header at 'tools/arch/x86/include/asm/msr-index.h' differs from latest version at 'arch/x86/include/asm/msr-index.h'

That makes the beautification scripts to pick some new entries:

$ tools/perf/trace/beauty/tracepoints/x86_msr.sh > before
$ cp arch/x86/include/asm/msr-index.h tools/arch/x86/include/asm/msr-index.h
$ tools/perf/trace/beauty/tracepoints/x86_msr.sh > after
$ diff -u before after
--- before 2022-12-20 14:28:40.893794072 -0300
+++ after 2022-12-20 14:28:54.831993914 -0300
@@ -266,6 +266,7 @@
[0xc0000104 - x86_64_specific_MSRs_offset] = "AMD64_TSC_RATIO",
[0xc000010e - x86_64_specific_MSRs_offset] = "AMD64_LBR_SELECT",
[0xc000010f - x86_64_specific_MSRs_offset] = "AMD_DBG_EXTN_CFG",
+ [0xc0000200 - x86_64_specific_MSRs_offset] = "IA32_MBA_BW_BASE",
[0xc0000300 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_STATUS",
[0xc0000301 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_CTL",
[0xc0000302 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_STATUS_CLR",
$

Now one can trace systemwide asking to see backtraces to where that MSR
is being read/written, see this example with a previous update:

# perf trace -e msr:*_msr/max-stack=32/ --filter="msr>=IA32_U_CET && msr<=IA32_INT_SSP_TAB"
^C#

If we use -v (verbose mode) we can see what it does behind the scenes:

# perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr>=IA32_U_CET && msr<=IA32_INT_SSP_TAB"
Using CPUID AuthenticAMD-25-21-0
0x6a0
0x6a8
New filter for msr:read_msr: (msr>=0x6a0 && msr<=0x6a8) && (common_pid != 597499 && common_pid != 3313)
0x6a0
0x6a8
New filter for msr:write_msr: (msr>=0x6a0 && msr<=0x6a8) && (common_pid != 597499 && common_pid != 3313)
mmap size 528384B
^C#

Example with a frequent msr:

# perf trace -v -e msr:*_msr/max-stack=32/ --filter="msr==IA32_SPEC_CTRL" --max-events 2
Using CPUID AuthenticAMD-25-21-0
0x48
New filter for msr:read_msr: (msr==0x48) && (common_pid != 2612129 && common_pid != 3841)
0x48
New filter for msr:write_msr: (msr==0x48) && (common_pid != 2612129 && common_pid != 3841)
mmap size 528384B
Looking at the vmlinux_path (8 entries long)
symsrc__init: build id mismatch for vmlinux.
Using /proc/kcore for kernel data
Using /proc/kallsyms for symbols
0.000 Timer/2525383 msr:write_msr(msr: IA32_SPEC_CTRL, val: 6)
do_trace_write_msr ([kernel.kallsyms])
do_trace_write_msr ([kernel.kallsyms])
__switch_to_xtra ([kernel.kallsyms])
__switch_to ([kernel.kallsyms])
__schedule ([kernel.kallsyms])
schedule ([kernel.kallsyms])
futex_wait_queue_me ([kernel.kallsyms])
futex_wait ([kernel.kallsyms])
do_futex ([kernel.kallsyms])
__x64_sys_futex ([kernel.kallsyms])
do_syscall_64 ([kernel.kallsyms])
entry_SYSCALL_64_after_hwframe ([kernel.kallsyms])
__futex_abstimed_wait_common64 (/usr/lib64/libpthread-2.33.so)
0.030 :0/0 msr:write_msr(msr: IA32_SPEC_CTRL, val: 2)
do_trace_write_msr ([kernel.kallsyms])
do_trace_write_msr ([kernel.kallsyms])
__switch_to_xtra ([kernel.kallsyms])
__switch_to ([kernel.kallsyms])
__schedule ([kernel.kallsyms])
schedule_idle ([kernel.kallsyms])
do_idle ([kernel.kallsyms])
cpu_startup_entry ([kernel.kallsyms])
secondary_startup_64_no_verify ([kernel.kallsyms])
#

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/lkml/
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/arch/x86/include/asm/msr-index.h | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/tools/arch/x86/include/asm/msr-index.h b/tools/arch/x86/include/asm/msr-index.h
index f17ade084720d508..37ff47552bcb7b57 100644
--- a/tools/arch/x86/include/asm/msr-index.h
+++ b/tools/arch/x86/include/asm/msr-index.h
@@ -4,12 +4,7 @@

#include <linux/bits.h>

-/*
- * CPU model specific register (MSR) numbers.
- *
- * Do not add new entries to this file unless the definitions are shared
- * between multiple compilation units.
- */
+/* CPU model specific register (MSR) numbers. */

/* x86-64 specific MSRs */
#define MSR_EFER 0xc0000080 /* extended feature register */
@@ -537,7 +532,7 @@
#define MSR_AMD64_DC_CFG 0xc0011022

#define MSR_AMD64_DE_CFG 0xc0011029
-#define MSR_AMD64_DE_CFG_LFENCE_SERIALIZE_BIT 1
+#define MSR_AMD64_DE_CFG_LFENCE_SERIALIZE_BIT 1
#define MSR_AMD64_DE_CFG_LFENCE_SERIALIZE BIT_ULL(MSR_AMD64_DE_CFG_LFENCE_SERIALIZE_BIT)

#define MSR_AMD64_BU_CFG2 0xc001102a
@@ -798,6 +793,7 @@
#define ENERGY_PERF_BIAS_PERFORMANCE 0
#define ENERGY_PERF_BIAS_BALANCE_PERFORMANCE 4
#define ENERGY_PERF_BIAS_NORMAL 6
+#define ENERGY_PERF_BIAS_NORMAL_POWERSAVE 7
#define ENERGY_PERF_BIAS_BALANCE_POWERSAVE 8
#define ENERGY_PERF_BIAS_POWERSAVE 15

@@ -1052,6 +1048,20 @@
#define VMX_BASIC_MEM_TYPE_WB 6LLU
#define VMX_BASIC_INOUT 0x0040000000000000LLU

+/* Resctrl MSRs: */
+/* - Intel: */
+#define MSR_IA32_L3_QOS_CFG 0xc81
+#define MSR_IA32_L2_QOS_CFG 0xc82
+#define MSR_IA32_QM_EVTSEL 0xc8d
+#define MSR_IA32_QM_CTR 0xc8e
+#define MSR_IA32_PQR_ASSOC 0xc8f
+#define MSR_IA32_L3_CBM_BASE 0xc90
+#define MSR_IA32_L2_CBM_BASE 0xd10
+#define MSR_IA32_MBA_THRTL_BASE 0xd50
+
+/* - AMD: */
+#define MSR_IA32_MBA_BW_BASE 0xc0000200
+
/* MSR_IA32_VMX_MISC bits */
#define MSR_IA32_VMX_MISC_INTEL_PT (1ULL << 14)
#define MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS (1ULL << 29)
--
2.38.1