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

From: Arnaldo Carvalho de Melo
Date: Fri Oct 14 2022 - 17:12:00 EST

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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:

b8d1d163604bd1e6 ("x86/apic: Don't disable x2APIC if locked")
ca5b7c0d9621702e ("perf/x86/amd/lbr: Add LbrExtV2 branch record support")

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 2022-10-14 18:06:34.294561729 -0300
+++ after 2022-10-14 18:06:41.285744044 -0300
@@ -264,6 +264,7 @@
[0xc0000102 - x86_64_specific_MSRs_offset] = "KERNEL_GS_BASE",
[0xc0000103 - x86_64_specific_MSRs_offset] = "TSC_AUX",
[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",
[0xc0000300 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_STATUS",
[0xc0000301 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_CTL",
$

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: Daniel Sneddon <daniel.sneddon@xxxxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Sandipan Das <sandipan.das@xxxxxxx>
Link: https://lore.kernel.org/lkml/
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/arch/x86/include/asm/msr-index.h | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/tools/arch/x86/include/asm/msr-index.h b/tools/arch/x86/include/asm/msr-index.h
index 6674bdb096f346d9..10ac52705892a168 100644
--- a/tools/arch/x86/include/asm/msr-index.h
+++ b/tools/arch/x86/include/asm/msr-index.h
@@ -155,6 +155,11 @@
* Return Stack Buffer Predictions.
*/

+#define ARCH_CAP_XAPIC_DISABLE BIT(21) /*
+ * IA32_XAPIC_DISABLE_STATUS MSR
+ * supported
+ */
+
#define MSR_IA32_FLUSH_CMD 0x0000010b
#define L1D_FLUSH BIT(0) /*
* Writeback and invalidate the
@@ -585,6 +590,9 @@
#define MSR_AMD64_PERF_CNTR_GLOBAL_CTL 0xc0000301
#define MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR 0xc0000302

+/* AMD Last Branch Record MSRs */
+#define MSR_AMD64_LBR_SELECT 0xc000010e
+
/* Fam 17h MSRs */
#define MSR_F17H_IRPERF 0xc00000e9

@@ -756,6 +764,8 @@
#define MSR_AMD_DBG_EXTN_CFG 0xc000010f
#define MSR_AMD_SAMP_BR_FROM 0xc0010300

+#define DBG_EXTN_CFG_LBRV2EN BIT_ULL(6)
+
#define MSR_IA32_MPERF 0x000000e7
#define MSR_IA32_APERF 0x000000e8

@@ -1054,4 +1064,12 @@
#define MSR_IA32_HW_FEEDBACK_PTR 0x17d0
#define MSR_IA32_HW_FEEDBACK_CONFIG 0x17d1

+/* x2APIC locked status */
+#define MSR_IA32_XAPIC_DISABLE_STATUS 0xBD
+#define LEGACY_XAPIC_DISABLED BIT(0) /*
+ * x2APIC mode is locked and
+ * disabling x2APIC will cause
+ * a #GP
+ */
+
#endif /* _ASM_X86_MSR_INDEX_H */
--
2.37.3