To pick up the changes in:

  dae1bd58 ("x86/msr-index: Add MSRs for XFD")

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:

  $ diff -u tools/arch/x86/include/asm/msr-index.h arch/x86/include/asm/msr-index.h
  --- tools/arch/x86/include/asm/msr-index.h	2021-07-15 16:17:01.819817827 -0300
  +++ arch/x86/include/asm/msr-index.h	2021-11-06 15:49:33.738517311 -0300
  @@ -625,6 +625,8 @@

   #define MSR_IA32_BNDCFGS_RSVD		0x00000ffc

  +#define MSR_IA32_XFD			0x000001c4
  +#define MSR_IA32_XFD_ERR		0x000001c5
   #define MSR_IA32_XSS			0x00000da0

   #define MSR_IA32_APICBASE		0x0000001b
  $ tools/perf/trace/beauty/tracepoints/x86_msr.sh > /tmp/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 > /tmp/after
  $ diff -u /tmp/before /tmp/after
  --- /tmp/before	2021-11-13 11:10:39.964201505 -0300
  +++ /tmp/after	2021-11-13 11:10:47.902410873 -0300
  @@ -93,6 +93,8 @@
   	[0x000001b0] = "IA32_ENERGY_PERF_BIAS",
   	[0x000001b1] = "IA32_PACKAGE_THERM_STATUS",
   	[0x000001b2] = "IA32_PACKAGE_THERM_INTERRUPT",
  +	[0x000001c4] = "IA32_XFD",
  +	[0x000001c5] = "IA32_XFD_ERR",
   	[0x000001c8] = "LBR_SELECT",
   	[0x000001c9] = "LBR_TOS",
   	[0x000001d9] = "IA32_DEBUGCTLMSR",
  $

And this gets rebuilt:

  CC       /tmp/build/perf/trace/beauty/tracepoints/x86_msr.o
  INSTALL  trace_plugins
  LD       /tmp/build/perf/trace/beauty/tracepoints/perf-in.o
  LD       /tmp/build/perf/trace/beauty/perf-in.o
  LD       /tmp/build/perf/perf-in.o
  LINK     /tmp/build/perf/perf

Now one can trace systemwide asking to see backtraces to where those
MSRs are being read/written with:

  # perf trace -e msr:*_msr/max-stack=32/ --filter="msr==IA32_XFD || msr==IA32_XFD_ERR"
  ^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_XFD || msr==IA32_XFD_ERR"
  <SNIP>
  New filter for msr:read_msr: (msr==0x1c4 || msr==0x1c5) && (common_pid != 4448951 && common_pid != 8781)
  New filter for msr:write_msr: (msr==0x1c4 || msr==0x1c5) && (common_pid != 4448951 && common_pid != 8781)
  <SNIP>
  ^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 != 3738351 && common_pid != 3564)
  0x48
  New filter for msr:write_msr: (msr==0x48) && (common_pid != 3738351 && common_pid != 3564)
  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 pipewire/2479 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])
                                         schedule_hrtimeout_range_clock ([kernel.kallsyms])
                                         do_epoll_wait ([kernel.kallsyms])
                                         __x64_sys_epoll_wait ([kernel.kallsyms])
                                         do_syscall_64 ([kernel.kallsyms])
                                         entry_SYSCALL_64_after_hwframe ([kernel.kallsyms])
                                         epoll_wait (/usr/lib64/libc-2.33.so)
                                         [0x76c4] (/usr/lib64/spa-0.2/support/libspa-support.so)
                                         [0x4cf0] (/usr/lib64/spa-0.2/support/libspa-support.so)
       0.027 :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])
                                         start_kernel ([kernel.kallsyms])
                                         secondary_startup_64_no_verify ([kernel.kallsyms])
  #

Cc: Borislav Petkov <bp@suse.de>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/YY%2FJdb6on7swsn+C@kernel.org/


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>