Re: [PATCH v14 1/1] perf tools: add support for libpfm4

[Ian Rogers]

On Tue, May 5, 2020 at 11:29 AM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>
> From: Stephane Eranian <eranian@xxxxxxxxxx>
>
> This patch links perf with the libpfm4 library if it is available
> and LIBPFM4 is passed to the build. The libpfm4 library
> contains hardware event tables for all processors supported by
> perf_events. It is a helper library that helps convert from a
> symbolic event name to the event encoding required by the
> underlying kernel interface. This library is open-source and
> available from: http://perfmon2.sf.net.
>
> With this patch, it is possible to specify full hardware events
> by name. Hardware filters are also supported. Events must be
> specified via the --pfm-events and not -e option. Both options
> are active at the same time and it is possible to mix and match:
>
> $ perf stat --pfm-events inst_retired:any_p:c=1:i -e cycles ....
>
> Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>
> Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>

Ping.

Thanks,
Ian

> ---
>  tools/perf/Documentation/perf-record.txt |  11 +
>  tools/perf/Documentation/perf-stat.txt   |  10 +
>  tools/perf/Documentation/perf-top.txt    |  11 +
>  tools/perf/Makefile.config               |  13 ++
>  tools/perf/Makefile.perf                 |   2 +
>  tools/perf/builtin-record.c              |   6 +
>  tools/perf/builtin-stat.c                |   6 +
>  tools/perf/builtin-top.c                 |   6 +
>  tools/perf/tests/Build                   |   1 +
>  tools/perf/tests/builtin-test.c          |   9 +
>  tools/perf/tests/pfm.c                   | 203 ++++++++++++++++
>  tools/perf/tests/tests.h                 |   3 +
>  tools/perf/util/Build                    |   2 +
>  tools/perf/util/evsel.c                  |   2 +-
>  tools/perf/util/evsel.h                  |   1 +
>  tools/perf/util/parse-events.c           |  30 ++-
>  tools/perf/util/parse-events.h           |   4 +
>  tools/perf/util/pfm.c                    | 281 +++++++++++++++++++++++
>  tools/perf/util/pfm.h                    |  37 +++
>  19 files changed, 630 insertions(+), 8 deletions(-)
>  create mode 100644 tools/perf/tests/pfm.c
>  create mode 100644 tools/perf/util/pfm.c
>  create mode 100644 tools/perf/util/pfm.h
>
> diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
> index 561ef55743e2..492b6b6f2b77 100644
> --- a/tools/perf/Documentation/perf-record.txt
> +++ b/tools/perf/Documentation/perf-record.txt
> @@ -613,6 +613,17 @@ appended unit character - B/K/M/G
>         The number of threads to run when synthesizing events for existing processes.
>         By default, the number of threads equals 1.
>
> +ifdef::HAVE_LIBPFM[]
> +--pfm-events events::
> +Select a PMU event using libpfm4 syntax (see http://perfmon2.sf.net)
> +including support for event filters. For example '--pfm-events
> +inst_retired:any_p:u:c=1:i'. More than one event can be passed to the
> +option using the comma separator. Hardware events and generic hardware
> +events cannot be mixed together. The latter must be used with the -e
> +option. The -e option and this one can be mixed and matched.  Events
> +can be grouped using the {} notation.
> +endif::HAVE_LIBPFM[]
> +
>  SEE ALSO
>  --------
>  linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-intel-pt[1]
> diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
> index 3fb5028aef08..b69af18dccd0 100644
> --- a/tools/perf/Documentation/perf-stat.txt
> +++ b/tools/perf/Documentation/perf-stat.txt
> @@ -71,6 +71,16 @@ report::
>  --tid=<tid>::
>          stat events on existing thread id (comma separated list)
>
> +ifdef::HAVE_LIBPFM[]
> +--pfm-events events::
> +Select a PMU event using libpfm4 syntax (see http://perfmon2.sf.net)
> +including support for event filters. For example '--pfm-events
> +inst_retired:any_p:u:c=1:i'. More than one event can be passed to the
> +option using the comma separator. Hardware events and generic hardware
> +events cannot be mixed together. The latter must be used with the -e
> +option. The -e option and this one can be mixed and matched.  Events
> +can be grouped using the {} notation.
> +endif::HAVE_LIBPFM[]
>
>  -a::
>  --all-cpus::
> diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt
> index 20227dabc208..ee2024691d46 100644
> --- a/tools/perf/Documentation/perf-top.txt
> +++ b/tools/perf/Documentation/perf-top.txt
> @@ -329,6 +329,17 @@ Default is to monitor all CPUS.
>         The known limitations include exception handing such as
>         setjmp/longjmp will have calls/returns not match.
>
> +ifdef::HAVE_LIBPFM[]
> +--pfm-events events::
> +Select a PMU event using libpfm4 syntax (see http://perfmon2.sf.net)
> +including support for event filters. For example '--pfm-events
> +inst_retired:any_p:u:c=1:i'. More than one event can be passed to the
> +option using the comma separator. Hardware events and generic hardware
> +events cannot be mixed together. The latter must be used with the -e
> +option. The -e option and this one can be mixed and matched.  Events
> +can be grouped using the {} notation.
> +endif::HAVE_LIBPFM[]
> +
>  INTERACTIVE PROMPTING KEYS
>  --------------------------
>
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index 12a8204d63c6..b67804fee1e3 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -1012,6 +1012,19 @@ ifdef LIBCLANGLLVM
>    endif
>  endif
>
> +ifdef LIBPFM4
> +  $(call feature_check,libpfm4)
> +  ifeq ($(feature-libpfm4), 1)
> +    CFLAGS += -DHAVE_LIBPFM
> +    EXTLIBS += -lpfm
> +    ASCIIDOC_EXTRA = -aHAVE_LIBPFM=1
> +    $(call detected,CONFIG_LIBPFM4)
> +  else
> +    msg := $(warning libpfm4 not found, disables libpfm4 support. Please install libpfm4-dev);
> +    NO_LIBPFM4 := 1
> +  endif
> +endif
> +
>  # Among the variables below, these:
>  #   perfexecdir
>  #   perf_include_dir
> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
> index 94a495594e99..dc82578c8773 100644
> --- a/tools/perf/Makefile.perf
> +++ b/tools/perf/Makefile.perf
> @@ -118,6 +118,8 @@ include ../scripts/utilities.mak
>  #
>  # Define LIBBPF_DYNAMIC to enable libbpf dynamic linking.
>  #
> +# Define LIBPFM4 to enable libpfm4 events extension.
> +#
>
>  # As per kernel Makefile, avoid funny character set dependencies
>  unexport LC_ALL
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index e4efdbf1a81e..98387cce3207 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -45,6 +45,7 @@
>  #include "util/units.h"
>  #include "util/bpf-event.h"
>  #include "util/util.h"
> +#include "util/pfm.h"
>  #include "asm/bug.h"
>  #include "perf.h"
>
> @@ -2506,6 +2507,11 @@ static struct option __record_options[] = {
>         OPT_UINTEGER(0, "num-thread-synthesize",
>                      &record.opts.nr_threads_synthesize,
>                      "number of threads to run for event synthesis"),
> +#ifdef HAVE_LIBPFM
> +       OPT_CALLBACK(0, "pfm-events", &record.evlist, "event",
> +               "libpfm4 event selector. use 'perf list' to list available events",
> +               parse_libpfm_events_option),
> +#endif
>         OPT_END()
>  };
>
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index e0c1ad23c768..f6e2dd57f48e 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -66,6 +66,7 @@
>  #include "util/time-utils.h"
>  #include "util/top.h"
>  #include "util/affinity.h"
> +#include "util/pfm.h"
>  #include "asm/bug.h"
>
>  #include <linux/time64.h>
> @@ -935,6 +936,11 @@ static struct option stat_options[] = {
>                     "Use with 'percore' event qualifier to show the event "
>                     "counts of one hardware thread by sum up total hardware "
>                     "threads of same physical core"),
> +#ifdef HAVE_LIBPFM
> +       OPT_CALLBACK(0, "pfm-events", &evsel_list, "event",
> +               "libpfm4 event selector. use 'perf list' to list available events",
> +               parse_libpfm_events_option),
> +#endif
>         OPT_END()
>  };
>
> diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
> index 372c38254654..20c41d9040ee 100644
> --- a/tools/perf/builtin-top.c
> +++ b/tools/perf/builtin-top.c
> @@ -53,6 +53,7 @@
>
>  #include "util/debug.h"
>  #include "util/ordered-events.h"
> +#include "util/pfm.h"
>
>  #include <assert.h>
>  #include <elf.h>
> @@ -1575,6 +1576,11 @@ int cmd_top(int argc, const char **argv)
>                     "WARNING: should be used on grouped events."),
>         OPT_BOOLEAN(0, "stitch-lbr", &top.stitch_lbr,
>                     "Enable LBR callgraph stitching approach"),
> +#ifdef HAVE_LIBPFM
> +       OPT_CALLBACK(0, "pfm-events", &top.evlist, "event",
> +               "libpfm4 event selector. use 'perf list' to list available events",
> +               parse_libpfm_events_option),
> +#endif
>         OPTS_EVSWITCH(&top.evswitch),
>         OPT_END()
>         };
> diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build
> index c75557aeef0e..4e74a363b0b0 100644
> --- a/tools/perf/tests/Build
> +++ b/tools/perf/tests/Build
> @@ -57,6 +57,7 @@ perf-y += maps.o
>  perf-y += time-utils-test.o
>  perf-y += genelf.o
>  perf-y += api-io.o
> +perf-y += pfm.o
>
>  $(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c tests/Build
>         $(call rule_mkdir)
> diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
> index 3471ec52ea11..57c6f8b31624 100644
> --- a/tools/perf/tests/builtin-test.c
> +++ b/tools/perf/tests/builtin-test.c
> @@ -317,6 +317,15 @@ static struct test generic_tests[] = {
>                 .desc = "maps__merge_in",
>                 .func = test__maps__merge_in,
>         },
> +       {
> +               .desc = "Test libpfm4 support",
> +               .func = test__pfm,
> +               .subtest = {
> +                       .skip_if_fail   = true,
> +                       .get_nr         = test__pfm_subtest_get_nr,
> +                       .get_desc       = test__pfm_subtest_get_desc,
> +               }
> +       },
>         {
>                 .func = NULL,
>         },
> diff --git a/tools/perf/tests/pfm.c b/tools/perf/tests/pfm.c
> new file mode 100644
> index 000000000000..76a53126efdf
> --- /dev/null
> +++ b/tools/perf/tests/pfm.c
> @@ -0,0 +1,203 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Test support for libpfm4 event encodings.
> + *
> + * Copyright 2020 Google LLC.
> + */
> +#include "tests.h"
> +#include "util/debug.h"
> +#include "util/evlist.h"
> +#include "util/pfm.h"
> +
> +#include <linux/kernel.h>
> +
> +#ifdef HAVE_LIBPFM
> +static int test__pfm_events(void);
> +static int test__pfm_group(void);
> +#endif
> +
> +static const struct {
> +       int (*func)(void);
> +       const char *desc;
> +} pfm_testcase_table[] = {
> +#ifdef HAVE_LIBPFM
> +       {
> +               .func = test__pfm_events,
> +               .desc = "test of individual --pfm-events",
> +       },
> +       {
> +               .func = test__pfm_group,
> +               .desc = "test groups of --pfm-events",
> +       },
> +#endif
> +};
> +
> +#ifdef HAVE_LIBPFM
> +static int count_pfm_events(struct perf_evlist *evlist)
> +{
> +       struct perf_evsel *evsel;
> +       int count = 0;
> +
> +       perf_evlist__for_each_entry(evlist, evsel) {
> +               count++;
> +       }
> +       return count;
> +}
> +
> +static int test__pfm_events(void)
> +{
> +       struct evlist *evlist;
> +       struct option opt;
> +       size_t i;
> +       const struct {
> +               const char *events;
> +               int nr_events;
> +       } table[] = {
> +               {
> +                       .events = "",
> +                       .nr_events = 0,
> +               },
> +               {
> +                       .events = "instructions",
> +                       .nr_events = 1,
> +               },
> +               {
> +                       .events = "instructions,cycles",
> +                       .nr_events = 2,
> +               },
> +               {
> +                       .events = "stereolab",
> +                       .nr_events = 0,
> +               },
> +               {
> +                       .events = "instructions,instructions",
> +                       .nr_events = 2,
> +               },
> +               {
> +                       .events = "stereolab,instructions",
> +                       .nr_events = 0,
> +               },
> +               {
> +                       .events = "instructions,stereolab",
> +                       .nr_events = 1,
> +               },
> +       };
> +
> +       for (i = 0; i < ARRAY_SIZE(table); i++) {
> +               evlist = evlist__new();
> +               if (evlist == NULL)
> +                       return -ENOMEM;
> +
> +               opt.value = evlist;
> +               parse_libpfm_events_option(&opt,
> +                                       table[i].events,
> +                                       0);
> +               TEST_ASSERT_EQUAL(table[i].events,
> +                               count_pfm_events(&evlist->core),
> +                               table[i].nr_events);
> +               TEST_ASSERT_EQUAL(table[i].events,
> +                               evlist->nr_groups,
> +                               0);
> +
> +               evlist__delete(evlist);
> +       }
> +       return 0;
> +}
> +
> +static int test__pfm_group(void)
> +{
> +       struct evlist *evlist;
> +       struct option opt;
> +       size_t i;
> +       const struct {
> +               const char *events;
> +               int nr_events;
> +               int nr_groups;
> +       } table[] = {
> +               {
> +                       .events = "{},",
> +                       .nr_events = 0,
> +                       .nr_groups = 0,
> +               },
> +               {
> +                       .events = "{instructions}",
> +                       .nr_events = 1,
> +                       .nr_groups = 1,
> +               },
> +               {
> +                       .events = "{instructions},{}",
> +                       .nr_events = 1,
> +                       .nr_groups = 1,
> +               },
> +               {
> +                       .events = "{},{instructions}",
> +                       .nr_events = 0,
> +                       .nr_groups = 0,
> +               },
> +               {
> +                       .events = "{instructions},{instructions}",
> +                       .nr_events = 2,
> +                       .nr_groups = 2,
> +               },
> +               {
> +                       .events = "{instructions,cycles},{instructions,cycles}",
> +                       .nr_events = 4,
> +                       .nr_groups = 2,
> +               },
> +               {
> +                       .events = "{stereolab}",
> +                       .nr_events = 0,
> +                       .nr_groups = 0,
> +               },
> +               {
> +                       .events =
> +                       "{instructions,cycles},{instructions,stereolab}",
> +                       .nr_events = 3,
> +                       .nr_groups = 1,
> +               },
> +       };
> +
> +       for (i = 0; i < ARRAY_SIZE(table); i++) {
> +               evlist = evlist__new();
> +               if (evlist == NULL)
> +                       return -ENOMEM;
> +
> +               opt.value = evlist;
> +               parse_libpfm_events_option(&opt,
> +                                       table[i].events,
> +                                       0);
> +               TEST_ASSERT_EQUAL(table[i].events,
> +                               count_pfm_events(&evlist->core),
> +                               table[i].nr_events);
> +               TEST_ASSERT_EQUAL(table[i].events,
> +                               evlist->nr_groups,
> +                               table[i].nr_groups);
> +
> +               evlist__delete(evlist);
> +       }
> +       return 0;
> +}
> +#endif
> +
> +const char *test__pfm_subtest_get_desc(int i)
> +{
> +       if (i < 0 || i >= (int)ARRAY_SIZE(pfm_testcase_table))
> +               return NULL;
> +       return pfm_testcase_table[i].desc;
> +}
> +
> +int test__pfm_subtest_get_nr(void)
> +{
> +       return (int)ARRAY_SIZE(pfm_testcase_table);
> +}
> +
> +int test__pfm(struct test *test __maybe_unused, int i __maybe_unused)
> +{
> +#ifdef HAVE_LIBPFM
> +       if (i < 0 || i >= (int)ARRAY_SIZE(pfm_testcase_table))
> +               return TEST_FAIL;
> +       return pfm_testcase_table[i].func();
> +#else
> +       return TEST_SKIP;
> +#endif
> +}
> diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
> index d6d4ac34eeb7..a2ae0d2e6087 100644
> --- a/tools/perf/tests/tests.h
> +++ b/tools/perf/tests/tests.h
> @@ -113,6 +113,9 @@ int test__maps__merge_in(struct test *t, int subtest);
>  int test__time_utils(struct test *t, int subtest);
>  int test__jit_write_elf(struct test *test, int subtest);
>  int test__api_io(struct test *test, int subtest);
> +int test__pfm(struct test *test, int subtest);
> +const char *test__pfm_subtest_get_desc(int subtest);
> +int test__pfm_subtest_get_nr(void);
>
>  bool test__bp_signal_is_supported(void);
>  bool test__bp_account_is_supported(void);
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index ca07a162d602..dfda916f0b4c 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -179,6 +179,8 @@ perf-$(CONFIG_LIBBPF) += bpf-event.o
>
>  perf-$(CONFIG_CXX) += c++/
>
> +perf-$(CONFIG_LIBPFM4) += pfm.o
> +
>  CFLAGS_config.o   += -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))"
>  CFLAGS_llvm-utils.o += -DPERF_INCLUDE_DIR="BUILD_STR($(perf_include_dir_SQ))"
>
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index f3e60c45d59a..d7ea1a7e74cd 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -2416,7 +2416,7 @@ bool evsel__fallback(struct evsel *evsel, int err, char *msg, size_t msgsize)
>
>                 /* Is there already the separator in the name. */
>                 if (strchr(name, '/') ||
> -                   strchr(name, ':'))
> +                   (strchr(name, ':') && !evsel->is_libpfm_event))
>                         sep = "";
>
>                 if (asprintf(&new_name, "%s%su", name, sep) < 0)
> diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
> index 351c0aaf2a11..5a4f20ddeb49 100644
> --- a/tools/perf/util/evsel.h
> +++ b/tools/perf/util/evsel.h
> @@ -76,6 +76,7 @@ struct evsel {
>         bool                    ignore_missing_thread;
>         bool                    forced_leader;
>         bool                    use_uncore_alias;
> +       bool                    is_libpfm_event;
>         /* parse modifier helper */
>         int                     exclude_GH;
>         int                     sample_read;
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index b7a0518d607d..0ee3338a0449 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -36,6 +36,7 @@
>  #include "metricgroup.h"
>  #include "util/evsel_config.h"
>  #include "util/event.h"
> +#include "util/pfm.h"
>
>  #define MAX_NAME_LEN 100
>
> @@ -344,6 +345,7 @@ static char *get_config_name(struct list_head *head_terms)
>  static struct evsel *
>  __add_event(struct list_head *list, int *idx,
>             struct perf_event_attr *attr,
> +           bool init_attr,
>             char *name, struct perf_pmu *pmu,
>             struct list_head *config_terms, bool auto_merge_stats,
>             const char *cpu_list)
> @@ -352,7 +354,8 @@ __add_event(struct list_head *list, int *idx,
>         struct perf_cpu_map *cpus = pmu ? pmu->cpus :
>                                cpu_list ? perf_cpu_map__new(cpu_list) : NULL;
>
> -       event_attr_init(attr);
> +       if (init_attr)
> +               event_attr_init(attr);
>
>         evsel = perf_evsel__new_idx(attr, *idx);
>         if (!evsel)
> @@ -370,15 +373,25 @@ __add_event(struct list_head *list, int *idx,
>         if (config_terms)
>                 list_splice(config_terms, &evsel->config_terms);
>
> -       list_add_tail(&evsel->core.node, list);
> +       if (list)
> +               list_add_tail(&evsel->core.node, list);
> +
>         return evsel;
>  }
>
> +struct evsel *parse_events__add_event(int idx, struct perf_event_attr *attr,
> +                                       char *name, struct perf_pmu *pmu)
> +{
> +       return __add_event(NULL, &idx, attr, false, name, pmu, NULL, false,
> +                          NULL);
> +}
> +
>  static int add_event(struct list_head *list, int *idx,
>                      struct perf_event_attr *attr, char *name,
>                      struct list_head *config_terms)
>  {
> -       return __add_event(list, idx, attr, name, NULL, config_terms, false, NULL) ? 0 : -ENOMEM;
> +       return __add_event(list, idx, attr, true, name, NULL, config_terms,
> +                          false, NULL) ? 0 : -ENOMEM;
>  }
>
>  static int add_event_tool(struct list_head *list, int *idx,
> @@ -390,7 +403,8 @@ static int add_event_tool(struct list_head *list, int *idx,
>                 .config = PERF_COUNT_SW_DUMMY,
>         };
>
> -       evsel = __add_event(list, idx, &attr, NULL, NULL, NULL, false, "0");
> +       evsel = __add_event(list, idx, &attr, true, NULL, NULL, NULL, false,
> +                           "0");
>         if (!evsel)
>                 return -ENOMEM;
>         evsel->tool_event = tool_event;
> @@ -1446,8 +1460,8 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
>
>         if (!head_config) {
>                 attr.type = pmu->type;
> -               evsel = __add_event(list, &parse_state->idx, &attr, NULL, pmu, NULL,
> -                                   auto_merge_stats, NULL);
> +               evsel = __add_event(list, &parse_state->idx, &attr, true, NULL,
> +                                   pmu, NULL, auto_merge_stats, NULL);
>                 if (evsel) {
>                         evsel->pmu_name = name ? strdup(name) : NULL;
>                         evsel->use_uncore_alias = use_uncore_alias;
> @@ -1488,7 +1502,7 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
>                 return -EINVAL;
>         }
>
> -       evsel = __add_event(list, &parse_state->idx, &attr,
> +       evsel = __add_event(list, &parse_state->idx, &attr, true,
>                             get_config_name(head_config), pmu,
>                             &config_terms, auto_merge_stats, NULL);
>         if (evsel) {
> @@ -2817,6 +2831,8 @@ void print_events(const char *event_glob, bool name_only, bool quiet_flag,
>         print_sdt_events(NULL, NULL, name_only);
>
>         metricgroup__print(true, true, NULL, name_only, details_flag);
> +
> +       print_libpfm_events(name_only, long_desc);
>  }
>
>  int parse_events__is_hardcoded_term(struct parse_events_term *term)
> diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
> index 6ead9661238c..04e3f627c081 100644
> --- a/tools/perf/util/parse-events.h
> +++ b/tools/perf/util/parse-events.h
> @@ -17,6 +17,7 @@ struct evlist;
>  struct parse_events_error;
>
>  struct option;
> +struct perf_pmu;
>
>  struct tracepoint_path {
>         char *system;
> @@ -187,6 +188,9 @@ int parse_events_add_pmu(struct parse_events_state *parse_state,
>                          bool auto_merge_stats,
>                          bool use_alias);
>
> +struct evsel *parse_events__add_event(int idx, struct perf_event_attr *attr,
> +                                       char *name, struct perf_pmu *pmu);
> +
>  int parse_events_multi_pmu_add(struct parse_events_state *parse_state,
>                                char *str,
>                                struct list_head **listp);
> diff --git a/tools/perf/util/pfm.c b/tools/perf/util/pfm.c
> new file mode 100644
> index 000000000000..d735acb6c29c
> --- /dev/null
> +++ b/tools/perf/util/pfm.c
> @@ -0,0 +1,281 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Support for libpfm4 event encoding.
> + *
> + * Copyright 2020 Google LLC.
> + */
> +#include "util/cpumap.h"
> +#include "util/debug.h"
> +#include "util/event.h"
> +#include "util/evlist.h"
> +#include "util/evsel.h"
> +#include "util/parse-events.h"
> +#include "util/pmu.h"
> +#include "util/pfm.h"
> +
> +#include <string.h>
> +#include <linux/kernel.h>
> +#include <perfmon/pfmlib_perf_event.h>
> +
> +static void libpfm_initialize(void)
> +{
> +       int ret;
> +
> +       ret = pfm_initialize();
> +       if (ret != PFM_SUCCESS) {
> +               ui__warning("libpfm failed to initialize: %s\n",
> +                       pfm_strerror(ret));
> +       }
> +}
> +
> +int parse_libpfm_events_option(const struct option *opt, const char *str,
> +                       int unset __maybe_unused)
> +{
> +       struct evlist *evlist = *(struct evlist **)opt->value;
> +       struct perf_event_attr attr;
> +       struct perf_pmu *pmu;
> +       struct evsel *evsel, *grp_leader = NULL;
> +       char *p, *q, *p_orig;
> +       const char *sep;
> +       int grp_evt = -1;
> +       int ret;
> +
> +       libpfm_initialize();
> +
> +       p_orig = p = strdup(str);
> +       if (!p)
> +               return -1;
> +       /*
> +        * force loading of the PMU list
> +        */
> +       perf_pmu__scan(NULL);
> +
> +       for (q = p; strsep(&p, ",{}"); q = p) {
> +               sep = p ? str + (p - p_orig - 1) : "";
> +               if (*sep == '{') {
> +                       if (grp_evt > -1) {
> +                               ui__error(
> +                                       "nested event groups not supported\n");
> +                               goto error;
> +                       }
> +                       grp_evt++;
> +               }
> +
> +               /* no event */
> +               if (*q == '\0')
> +                       continue;
> +
> +               memset(&attr, 0, sizeof(attr));
> +               event_attr_init(&attr);
> +
> +               ret = pfm_get_perf_event_encoding(q, PFM_PLM0|PFM_PLM3,
> +                                               &attr, NULL, NULL);
> +
> +               if (ret != PFM_SUCCESS) {
> +                       ui__error("failed to parse event %s : %s\n", str,
> +                                 pfm_strerror(ret));
> +                       goto error;
> +               }
> +
> +               pmu = perf_pmu__find_by_type((unsigned int)attr.type);
> +               evsel = parse_events__add_event(evlist->core.nr_entries,
> +                                               &attr, q, pmu);
> +               if (evsel == NULL)
> +                       goto error;
> +
> +               evsel->is_libpfm_event = true;
> +
> +               evlist__add(evlist, evsel);
> +
> +               if (grp_evt == 0)
> +                       grp_leader = evsel;
> +
> +               if (grp_evt > -1) {
> +                       evsel->leader = grp_leader;
> +                       grp_leader->core.nr_members++;
> +                       grp_evt++;
> +               }
> +
> +               if (*sep == '}') {
> +                       if (grp_evt < 0) {
> +                               ui__error(
> +                                  "cannot close a non-existing event group\n");
> +                               goto error;
> +                       }
> +                       evlist->nr_groups++;
> +                       grp_leader = NULL;
> +                       grp_evt = -1;
> +               }
> +       }
> +       return 0;
> +error:
> +       free(p_orig);
> +       return -1;
> +}
> +
> +static const char *srcs[PFM_ATTR_CTRL_MAX] = {
> +       [PFM_ATTR_CTRL_UNKNOWN] = "???",
> +       [PFM_ATTR_CTRL_PMU] = "PMU",
> +       [PFM_ATTR_CTRL_PERF_EVENT] = "perf_event",
> +};
> +
> +static void
> +print_attr_flags(pfm_event_attr_info_t *info)
> +{
> +       int n = 0;
> +
> +       if (info->is_dfl) {
> +               printf("[default] ");
> +               n++;
> +       }
> +
> +       if (info->is_precise) {
> +               printf("[precise] ");
> +               n++;
> +       }
> +
> +       if (!n)
> +               printf("- ");
> +}
> +
> +static void
> +print_libpfm_events_detailed(pfm_event_info_t *info, bool long_desc)
> +{
> +       pfm_event_attr_info_t ainfo;
> +       const char *src;
> +       int j, ret;
> +
> +       ainfo.size = sizeof(ainfo);
> +
> +       printf("  %s\n", info->name);
> +       printf("    [%s]\n", info->desc);
> +       if (long_desc) {
> +               if (info->equiv)
> +                       printf("      Equiv: %s\n", info->equiv);
> +
> +               printf("      Code  : 0x%"PRIx64"\n", info->code);
> +       }
> +       pfm_for_each_event_attr(j, info) {
> +               ret = pfm_get_event_attr_info(info->idx, j,
> +                                             PFM_OS_PERF_EVENT_EXT, &ainfo);
> +               if (ret != PFM_SUCCESS)
> +                       continue;
> +
> +               if (ainfo.type == PFM_ATTR_UMASK) {
> +                       printf("      %s:%s\n", info->name, ainfo.name);
> +                       printf("        [%s]\n", ainfo.desc);
> +               }
> +
> +               if (!long_desc)
> +                       continue;
> +
> +               if (ainfo.ctrl >= PFM_ATTR_CTRL_MAX)
> +                       ainfo.ctrl = PFM_ATTR_CTRL_UNKNOWN;
> +
> +               src = srcs[ainfo.ctrl];
> +               switch (ainfo.type) {
> +               case PFM_ATTR_UMASK:
> +                       printf("        Umask : 0x%02"PRIx64" : %s: ",
> +                               ainfo.code, src);
> +                       print_attr_flags(&ainfo);
> +                       putchar('\n');
> +                       break;
> +               case PFM_ATTR_MOD_BOOL:
> +                       printf("      Modif : %s: [%s] : %s (boolean)\n", src,
> +                               ainfo.name, ainfo.desc);
> +                       break;
> +               case PFM_ATTR_MOD_INTEGER:
> +                       printf("      Modif : %s: [%s] : %s (integer)\n", src,
> +                               ainfo.name, ainfo.desc);
> +                       break;
> +               case PFM_ATTR_NONE:
> +               case PFM_ATTR_RAW_UMASK:
> +               case PFM_ATTR_MAX:
> +               default:
> +                       printf("      Attr  : %s: [%s] : %s\n", src,
> +                               ainfo.name, ainfo.desc);
> +               }
> +       }
> +}
> +
> +/*
> + * list all pmu::event:umask, pmu::event
> + * printed events may not be all valid combinations of umask for an event
> + */
> +static void
> +print_libpfm_events_raw(pfm_pmu_info_t *pinfo, pfm_event_info_t *info)
> +{
> +       pfm_event_attr_info_t ainfo;
> +       int j, ret;
> +       bool has_umask = false;
> +
> +       ainfo.size = sizeof(ainfo);
> +
> +       pfm_for_each_event_attr(j, info) {
> +               ret = pfm_get_event_attr_info(info->idx, j,
> +                                             PFM_OS_PERF_EVENT_EXT, &ainfo);
> +               if (ret != PFM_SUCCESS)
> +                       continue;
> +
> +               if (ainfo.type != PFM_ATTR_UMASK)
> +                       continue;
> +
> +               printf("%s::%s:%s\n", pinfo->name, info->name, ainfo.name);
> +               has_umask = true;
> +       }
> +       if (!has_umask)
> +               printf("%s::%s\n", pinfo->name, info->name);
> +}
> +
> +void print_libpfm_events(bool name_only, bool long_desc)
> +{
> +       pfm_event_info_t info;
> +       pfm_pmu_info_t pinfo;
> +       int i, p, ret;
> +
> +       libpfm_initialize();
> +
> +       /* initialize to zero to indicate ABI version */
> +       info.size  = sizeof(info);
> +       pinfo.size = sizeof(pinfo);
> +
> +       if (!name_only)
> +               puts("\nList of pre-defined events (to be used in --pfm-events):\n");
> +
> +       pfm_for_all_pmus(p) {
> +               bool printed_pmu = false;
> +
> +               ret = pfm_get_pmu_info(p, &pinfo);
> +               if (ret != PFM_SUCCESS)
> +                       continue;
> +
> +               /* only print events that are supported by host HW */
> +               if (!pinfo.is_present)
> +                       continue;
> +
> +               /* handled by perf directly */
> +               if (pinfo.pmu == PFM_PMU_PERF_EVENT)
> +                       continue;
> +
> +               for (i = pinfo.first_event; i != -1;
> +                    i = pfm_get_event_next(i)) {
> +
> +                       ret = pfm_get_event_info(i, PFM_OS_PERF_EVENT_EXT,
> +                                               &info);
> +                       if (ret != PFM_SUCCESS)
> +                               continue;
> +
> +                       if (!name_only && !printed_pmu) {
> +                               printf("%s:\n", pinfo.name);
> +                               printed_pmu = true;
> +                       }
> +
> +                       if (!name_only)
> +                               print_libpfm_events_detailed(&info, long_desc);
> +                       else
> +                               print_libpfm_events_raw(&pinfo, &info);
> +               }
> +               if (!name_only && printed_pmu)
> +                       putchar('\n');
> +       }
> +}
> diff --git a/tools/perf/util/pfm.h b/tools/perf/util/pfm.h
> new file mode 100644
> index 000000000000..7d70dda87012
> --- /dev/null
> +++ b/tools/perf/util/pfm.h
> @@ -0,0 +1,37 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Support for libpfm4 event encoding.
> + *
> + * Copyright 2020 Google LLC.
> + */
> +#ifndef __PERF_PFM_H
> +#define __PERF_PFM_H
> +
> +#include <subcmd/parse-options.h>
> +
> +#ifdef HAVE_LIBPFM
> +int parse_libpfm_events_option(const struct option *opt, const char *str,
> +                       int unset);
> +
> +void print_libpfm_events(bool name_only, bool long_desc);
> +
> +#else
> +#include <linux/compiler.h>
> +
> +static inline int parse_libpfm_events_option(
> +       const struct option *opt __maybe_unused,
> +       const char *str __maybe_unused,
> +       int unset __maybe_unused)
> +{
> +       return 0;
> +}
> +
> +static inline void print_libpfm_events(bool name_only __maybe_unused,
> +                                      bool long_desc __maybe_unused)
> +{
> +}
> +
> +#endif
> +
> +
> +#endif /* __PERF_PFM_H */
> --
> 2.26.2.526.g744177e7f7-goog
>