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

From: Arnaldo Carvalho de Melo
Date: Fri Mar 03 2023 - 16:36:50 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:

e7862eda309ecfcc ("x86/cpu: Support AMD Automatic IBRS")
0125acda7d76b943 ("x86/bugs: Reset speculation control settings on init")
38aaf921e92dc5cf ("perf/x86: Add Meteor Lake support")
8c29f01654053258 ("x86/sev: Add SEV-SNP guest feature negotiation support")
5b6fac3fa44bafee ("x86/resctrl: Detect and configure Slow Memory Bandwidth Allocation")
dc2a3e857981f859 ("x86/resctrl: Add interface to read mbm_total_bytes_config")

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 2023-03-03 18:26:51.766923522 -0300
+++ after 2023-03-03 18:27:09.987415481 -0300
@@ -267,9 +267,11 @@
[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",
+ [0xc0000280 - x86_64_specific_MSRs_offset] = "IA32_SMBA_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",
+ [0xc0000400 - x86_64_specific_MSRs_offset] = "IA32_EVT_CFG_BASE",
};

#define x86_AMD_V_KVM_MSRs_offset 0xc0010000
$

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: Babu Moger <babu.moger@xxxxxxx>
Cc: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Cc: Breno Leitao <leitao@xxxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Kim Phillips <kim.phillips@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Nikunj A Dadhania <nikunj@xxxxxxx>
Link: https://lore.kernel.org/lkml/
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/arch/x86/include/asm/msr-index.h | 31 ++++++++++++++++++++++++++
1 file changed, 31 insertions(+)

diff --git a/tools/arch/x86/include/asm/msr-index.h b/tools/arch/x86/include/asm/msr-index.h
index 37ff47552bcb7b57..ad35355ee43ead14 100644
--- a/tools/arch/x86/include/asm/msr-index.h
+++ b/tools/arch/x86/include/asm/msr-index.h
@@ -25,6 +25,7 @@
#define _EFER_SVME 12 /* Enable virtualization */
#define _EFER_LMSLE 13 /* Long Mode Segment Limit Enable */
#define _EFER_FFXSR 14 /* Enable Fast FXSAVE/FXRSTOR */
+#define _EFER_AUTOIBRS 21 /* Enable Automatic IBRS */

#define EFER_SCE (1<<_EFER_SCE)
#define EFER_LME (1<<_EFER_LME)
@@ -33,6 +34,7 @@
#define EFER_SVME (1<<_EFER_SVME)
#define EFER_LMSLE (1<<_EFER_LMSLE)
#define EFER_FFXSR (1<<_EFER_FFXSR)
+#define EFER_AUTOIBRS (1<<_EFER_AUTOIBRS)

/* Intel MSRs. Some also available on other CPUs */

@@ -49,6 +51,10 @@
#define SPEC_CTRL_RRSBA_DIS_S_SHIFT 6 /* Disable RRSBA behavior */
#define SPEC_CTRL_RRSBA_DIS_S BIT(SPEC_CTRL_RRSBA_DIS_S_SHIFT)

+/* A mask for bits which the kernel toggles when controlling mitigations */
+#define SPEC_CTRL_MITIGATIONS_MASK (SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | SPEC_CTRL_SSBD \
+ | SPEC_CTRL_RRSBA_DIS_S)
+
#define MSR_IA32_PRED_CMD 0x00000049 /* Prediction Command */
#define PRED_CMD_IBPB BIT(0) /* Indirect Branch Prediction Barrier */

@@ -189,6 +195,9 @@
#define MSR_TURBO_RATIO_LIMIT1 0x000001ae
#define MSR_TURBO_RATIO_LIMIT2 0x000001af

+#define MSR_SNOOP_RSP_0 0x00001328
+#define MSR_SNOOP_RSP_1 0x00001329
+
#define MSR_LBR_SELECT 0x000001c8
#define MSR_LBR_TOS 0x000001c9

@@ -566,6 +575,26 @@
#define MSR_AMD64_SEV_ES_ENABLED BIT_ULL(MSR_AMD64_SEV_ES_ENABLED_BIT)
#define MSR_AMD64_SEV_SNP_ENABLED BIT_ULL(MSR_AMD64_SEV_SNP_ENABLED_BIT)

+/* SNP feature bits enabled by the hypervisor */
+#define MSR_AMD64_SNP_VTOM BIT_ULL(3)
+#define MSR_AMD64_SNP_REFLECT_VC BIT_ULL(4)
+#define MSR_AMD64_SNP_RESTRICTED_INJ BIT_ULL(5)
+#define MSR_AMD64_SNP_ALT_INJ BIT_ULL(6)
+#define MSR_AMD64_SNP_DEBUG_SWAP BIT_ULL(7)
+#define MSR_AMD64_SNP_PREVENT_HOST_IBS BIT_ULL(8)
+#define MSR_AMD64_SNP_BTB_ISOLATION BIT_ULL(9)
+#define MSR_AMD64_SNP_VMPL_SSS BIT_ULL(10)
+#define MSR_AMD64_SNP_SECURE_TSC BIT_ULL(11)
+#define MSR_AMD64_SNP_VMGEXIT_PARAM BIT_ULL(12)
+#define MSR_AMD64_SNP_IBS_VIRT BIT_ULL(14)
+#define MSR_AMD64_SNP_VMSA_REG_PROTECTION BIT_ULL(16)
+#define MSR_AMD64_SNP_SMT_PROTECTION BIT_ULL(17)
+
+/* SNP feature bits reserved for future use. */
+#define MSR_AMD64_SNP_RESERVED_BIT13 BIT_ULL(13)
+#define MSR_AMD64_SNP_RESERVED_BIT15 BIT_ULL(15)
+#define MSR_AMD64_SNP_RESERVED_MASK GENMASK_ULL(63, 18)
+
#define MSR_AMD64_VIRT_SPEC_CTRL 0xc001011f

/* AMD Collaborative Processor Performance Control MSRs */
@@ -1061,6 +1090,8 @@

/* - AMD: */
#define MSR_IA32_MBA_BW_BASE 0xc0000200
+#define MSR_IA32_SMBA_BW_BASE 0xc0000280
+#define MSR_IA32_EVT_CFG_BASE 0xc0000400

/* MSR_IA32_VMX_MISC bits */
#define MSR_IA32_VMX_MISC_INTEL_PT (1ULL << 14)
--
2.39.2