Arnaldo Carvalho de Melo 9dde6cadb9 tools arch x86: Sync the msr-index.h copy with the kernel sources
To pick up the changes in:

  db1af12929 ("x86/msr-index: Define INTEGRITY_CAPABILITIES MSR")
  089be16d59 ("x86/msr: Add PerfCntrGlobal* registers")
  f52ba93190 ("tools/power turbostat: Add Power Limit4 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	2022-05-26 12:50:01.228612839 -0300
  +++ after	2022-05-26 12:50:07.699776166 -0300
  @@ -116,6 +116,7 @@
   	[0x0000026f] = "MTRRfix4K_F8000",
   	[0x00000277] = "IA32_CR_PAT",
   	[0x00000280] = "IA32_MC0_CTL2",
  +	[0x000002d9] = "INTEGRITY_CAPS",
   	[0x000002ff] = "MTRRdefType",
   	[0x00000309] = "CORE_PERF_FIXED_CTR0",
   	[0x0000030a] = "CORE_PERF_FIXED_CTR1",
  @@ -176,6 +177,7 @@
   	[0x00000586] = "IA32_RTIT_ADDR3_A",
   	[0x00000587] = "IA32_RTIT_ADDR3_B",
   	[0x00000600] = "IA32_DS_AREA",
  +	[0x00000601] = "VR_CURRENT_CONFIG",
   	[0x00000606] = "RAPL_POWER_UNIT",
   	[0x0000060a] = "PKGC3_IRTL",
   	[0x0000060b] = "PKGC6_IRTL",
  @@ -260,6 +262,10 @@
   	[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",
  +	[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",
  +	[0xc0000302 - x86_64_specific_MSRs_offset] = "AMD64_PERF_CNTR_GLOBAL_STATUS_CLR",
   };

   #define x86_AMD_V_KVM_MSRs_offset 0xc0010000
  @@ -318,4 +324,5 @@
   	[0xc00102b4 - x86_AMD_V_KVM_MSRs_offset] = "AMD_CPPC_STATUS",
   	[0xc00102f0 - x86_AMD_V_KVM_MSRs_offset] = "AMD_PPIN_CTL",
   	[0xc00102f1 - x86_AMD_V_KVM_MSRs_offset] = "AMD_PPIN",
  +	[0xc0010300 - x86_AMD_V_KVM_MSRs_offset] = "AMD_SAMP_BR_FROM",
   };
  $

Now one can trace systemwide asking to see backtraces to where those
MSRs are 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@intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Sumeet Pawnikar <sumeet.r.pawnikar@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/lkml/Yo+i%252Fj5+UtE9dcix@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-05-27 13:22:14 -03:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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Linux kernel source tree
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