linux-stable.git/tools/perf/util/intel-pt-decoder, branch v5.12.2

perf intel-pt: Amend decoder to track the NR flag

2021-02-18T19:13:56+00:00

The PIP packet NR (non-root) flag indicates whether or not a virtual
machine is being traced (NR=1 => VM). Add support for tracking its value.

In particular note that the PIP packet (outside of PSB+) will be
associated with a TIP packet from which address the NR value takes
effect. At that point, there is a branch from_ip, to_ip with
corresponding from_nr and to_nr.

In the event of VM-Entry failure, there should still PIP and TIP packets
that can be followed in the same way.

Also note that this assumes that a host VMM is not employing VMX controls
that affect Intel PT, e.g. to hide the host from a guest using Intel PT.

Signed-off-by: Adrian Hunter 
Acked-by: Andi Kleen 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Link: https://lore.kernel.org/r/20210218095801.19576-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Retain the last PIP packet payload as is

2021-02-18T19:13:46+00:00

Retain the PIP packet payload as is, instead of just the CR3, because it
contains also the VMX NR flag which is needed to track VM-Entry.

Signed-off-by: Adrian Hunter 
Acked-by: Andi Kleen 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Link: https://lore.kernel.org/r/20210218095801.19576-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf intel_pt: Add vmlaunch and vmresume as branches

2021-02-18T19:13:30+00:00

In preparation to support Intel PT decoding of virtual machine traces, add
vmlaunch and vmresume as branch instructions.

Note, sample flags will show "VMentry" even if the VM-Entry fails.

Signed-off-by: Adrian Hunter 
Acked-by: Andi Kleen 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Link: https://lore.kernel.org/r/20210218095801.19576-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Add PSB events

2021-02-18T19:04:10+00:00

Emitting a PSB+ can cause a CPU a slight delay. When doing timing analysis
of code with Intel PT, it is useful to know if a timing bubble was caused
by Intel PT or not. Add reporting of PSB events via perf script. PSB
events are printed with the existing itrace 'p' option which also prints
power and frequency changes. The PSB event contains the trace offset at
which the PSB occurs, to allow easy reference back to the PSB+ packets.

The PSB event timestamp is always the timestamp from the PSB+ TSC
packet, and the ip is always the address from the PSB+ FUP packet.

The code changes are non-trivial because the decoder must walk to the
PSB+ FUP address before outputting the PSB event.

Example:

  $ perf record -e intel_pt/cyc,psb_period=0/u uname
  Linux
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.046 MB perf.data ]
  $ perf script --itrace=p --ns
     perf 17981 [006] 25617.510820383:  psb:  psb offs: 0                               0 [unknown] ([unknown])
     perf 17981 [006] 25617.510820383:  cbr:  cbr: 42 freq: 4219 MHz (156%)             0 [unknown] ([unknown])
    uname 17981 [006] 25617.510889753:  psb:  psb offs: 0xb50                7f78c12a212e __GI___tunables_init+0xee (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.510899162:  psb:  psb offs: 0x12d0               7f78c128af1c dl_main+0x93c (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.510939242:  psb:  psb offs: 0x1a50               7f78c128eefc _dl_map_object_from_fd+0x13c (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.510981274:  psb:  psb offs: 0x21c8               7f78c1296307 _dl_relocate_object+0x927 (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.510993034:  psb:  psb offs: 0x2948               7f78c12940e4 _dl_lookup_symbol_x+0x14 (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.511003871:  psb:  psb offs: 0x30c8               7f78c12937b3 do_lookup_x+0x2f3 (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.511019854:  psb:  psb offs: 0x3850               7f78c1295eed _dl_relocate_object+0x50d (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.511029015:  psb:  psb offs: 0x4390               7f78c12a855a strcmp+0xf6a (/usr/lib/x86_64-linux-gnu/ld-2.31.so)
    uname 17981 [006] 25617.511064876:  psb:  psb offs: 0x4b10                          0 [unknown] ([unknown])
    uname 17981 [006] 25617.511080762:  psb:  psb offs: 0x5290               7f78c11db53d _dl_addr+0x13d (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511086035:  psb:  psb offs: 0x5a08               7f78c11db538 _dl_addr+0x138 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511091381:  psb:  psb offs: 0x6190               7f78c11db534 _dl_addr+0x134 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511096681:  psb:  psb offs: 0x6910               7f78c11db4c3 _dl_addr+0xc3 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511119520:  psb:  psb offs: 0x7090               7f78c10ada5e _nl_intern_locale_data+0x12e (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511126584:  psb:  psb offs: 0x7818               7f78c10ada50 _nl_intern_locale_data+0x120 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511132775:  psb:  psb offs: 0x8358               7f78c10c20c0 getenv+0xa0 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511134598:  psb:  psb offs: 0x8ad0               7f78c10ada09 _nl_intern_locale_data+0xd9 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511135685:  psb:  psb offs: 0x9258               7f78c10ada50 _nl_intern_locale_data+0x120 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511138322:  psb:  psb offs: 0x99d0               7f78c11fffd9 __strncmp_avx2+0x39 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
    uname 17981 [006] 25617.511158907:  psb:  psb offs: 0xa150                          0 [unknown] ([unknown])

Signed-off-by: Adrian Hunter 
Reviewed-by: Andi Kleen 
Cc: Jiri Olsa 
Link: https://lore.kernel.org/r/20210205175350.23817-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Fix IPC with CYC threshold

2021-02-18T19:03:54+00:00

The code assumed every CYC-eligible packet has a CYC packet, which is not
the case when CYC thresholds are used. Fix by checking if a CYC packet is
actually present in that case.

Fixes: 5b1dc0fd1da06 ("perf intel-pt: Add support for samples to contain IPC ratio")
Signed-off-by: Adrian Hunter 
Reviewed-by: Andi Kleen 
Cc: Jiri Olsa 
Link: https://lore.kernel.org/r/20210205175350.23817-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Fix premature IPC

2021-02-18T19:03:37+00:00

The code assumed a change in cycle count means accurate IPC. That is not
correct, for example when sampling both branches and instructions, or at
a FUP packet (which is not CYC-eligible) address. Fix by using an explicit
flag to indicate when IPC can be sampled.

Fixes: 5b1dc0fd1da06 ("perf intel-pt: Add support for samples to contain IPC ratio")
Signed-off-by: Adrian Hunter 
Reviewed-by: Andi Kleen 
Cc: Jiri Olsa 
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/20210205175350.23817-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Fix missing CYC processing in PSB

2021-02-18T19:03:19+00:00

Add missing CYC packet processing when walking through PSB+. This
improves the accuracy of timestamps that follow PSB+, until the next
MTC.

Fixes: 3d49807870f08 ("perf tools: Add new Intel PT packet definitions")
Signed-off-by: Adrian Hunter 
Reviewed-by: Andi Kleen 
Cc: Jiri Olsa 
Link: https://lore.kernel.org/r/20210205175350.23817-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Add support for decoding PSB+ only

2020-08-06T12:02:43+00:00

A single q option decodes ip from only FUP/TIP packets. Make it so that
repeating the q option (i.e. qq) decodes only PSB+, getting ip if there
is a FUP packet within PSB+ (i.e. between PSB and PSBEND).

Example:

 $ perf record -e intel_pt//u grep -rI pudding drivers
 [ perf record: Woken up 52 times to write data ]
 [ perf record: Captured and wrote 57.870 MB perf.data ]
 $ time perf script --itrace=bi | wc -l
 58948289

 real    1m23.863s
 user    1m23.251s
 sys     0m7.452s
 $ time perf script --itrace=biq | wc -l
 3385694

 real    0m4.453s
 user    0m4.455s
 sys     0m0.328s
 $ time perf script --itrace=biqq | wc -l
 1883

 real    0m0.047s
 user    0m0.043s
 sys     0m0.009s

Signed-off-by: Adrian Hunter 
Reviewed-by: Andi Kleen 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Link: http://lore.kernel.org/lkml/20200710151104.15137-13-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Add support for decoding FUP/TIP only

2020-08-06T12:02:14+00:00

Use the new itrace 'q' option to add support for a mode of decoding that
ignores TNT, does not walk object code, but gets the ip from FUP and TIP
packets.

Example:

 $ perf record -e intel_pt//u grep -rI pudding drivers
 [ perf record: Woken up 52 times to write data ]
 [ perf record: Captured and wrote 57.870 MB perf.data ]
 $ time perf script --itrace=bi | wc -l
 58948289

 real    1m23.863s
 user    1m23.251s
 sys     0m7.452s
 $ time perf script --itrace=biq | wc -l
 3385694

 real    0m4.453s
 user    0m4.455s
 sys     0m0.328s

Signed-off-by: Adrian Hunter 
Reviewed-by: Andi Kleen 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Link: http://lore.kernel.org/lkml/20200710151104.15137-12-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Fix duplicate branch after CBR

2020-08-06T11:18:32+00:00

CBR events can result in a duplicate branch event, because the state
type defaults to a branch. Fix by clearing the state type.

Example: trace 'sleep' and hope for a frequency change

 Before:

   $ perf record -e intel_pt//u sleep 0.1
   [ perf record: Woken up 1 times to write data ]
   [ perf record: Captured and wrote 0.034 MB perf.data ]
   $ perf script --itrace=bpe > before.txt

 After:

   $ perf script --itrace=bpe > after.txt
   $ diff -u before.txt after.txt
   --- before.txt  2020-07-07 14:42:18.191508098 +0300
   +++ after.txt   2020-07-07 14:42:36.587891753 +0300
   @@ -29673,7 +29673,6 @@
               sleep 93431 [007] 15411.619905:          1  branches:u:                 0 [unknown] ([unknown]) =>     7f0818abb2e0 clock_nanosleep@@GLIBC_2.17+0x0 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
               sleep 93431 [007] 15411.619905:          1  branches:u:      7f0818abb30c clock_nanosleep@@GLIBC_2.17+0x2c (/usr/lib/x86_64-linux-gnu/libc-2.31.so) =>                0 [unknown] ([unknown])
               sleep 93431 [007] 15411.720069:         cbr:  cbr: 15 freq: 1507 MHz ( 56%)         7f0818abb30c clock_nanosleep@@GLIBC_2.17+0x2c (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
   -           sleep 93431 [007] 15411.720069:          1  branches:u:      7f0818abb30c clock_nanosleep@@GLIBC_2.17+0x2c (/usr/lib/x86_64-linux-gnu/libc-2.31.so) =>                0 [unknown] ([unknown])
               sleep 93431 [007] 15411.720076:          1  branches:u:                 0 [unknown] ([unknown]) =>     7f0818abb30e clock_nanosleep@@GLIBC_2.17+0x2e (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
               sleep 93431 [007] 15411.720077:          1  branches:u:      7f0818abb323 clock_nanosleep@@GLIBC_2.17+0x43 (/usr/lib/x86_64-linux-gnu/libc-2.31.so) =>     7f0818ac0eb7 __nanosleep+0x17 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
               sleep 93431 [007] 15411.720077:          1  branches:u:      7f0818ac0ebf __nanosleep+0x1f (/usr/lib/x86_64-linux-gnu/libc-2.31.so) =>     55cb7e4c2827 rpl_nanosleep+0x97 (/usr/bin/sleep)

Fixes: 91de8684f1cff ("perf intel-pt: Cater for CBR change in PSB+")
Fixes: abe5a1d3e4bee ("perf intel-pt: Decoder to output CBR changes immediately")
Signed-off-by: Adrian Hunter 
Reviewed-by: Andi Kleen 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200710151104.15137-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo