perf intel-pt: Synthesize CFE (Control Flow Event) / EVD (Event Data) event

Synthesize an attribute event and sample events for Intel PT Event Trace
events represented by CFE and EVD packets.

Committer notes:

Make 'struct perf_synth_intel_evd evd[]' evd[0] at the end of 'struct
perf_synth_intel_evt' as it is breaking the build with in many compilers
with (e.g. clang version 13.0.0 (Fedora 13.0.0-3.fc35)):

  util/intel-pt.c:2213:31: error: field 'cfe' with variable sized type 'struct perf_synth_intel_evt' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end]
                  struct perf_synth_intel_evt cfe;
                                              ^

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20220124084201.2699795-15-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 320cbcd..cdd72e0 100644 (file)
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -308,7 +308,7 @@ struct perf_synth_intel_evt {
                };
                u32     cfe;
        };
-       struct perf_synth_intel_evd evd[];
+       struct perf_synth_intel_evd evd[0];
 };
 
 struct perf_synth_intel_iflag_chg {

diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
index 23cb272..1e07a3c 100644 (file)
--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -49,6 +49,7 @@
 #define INTEL_PT_CFG_PASS_THRU BIT_ULL(0)
 #define INTEL_PT_CFG_PWR_EVT_EN        BIT_ULL(4)
 #define INTEL_PT_CFG_BRANCH_EN BIT_ULL(13)
+#define INTEL_PT_CFG_EVT_EN    BIT_ULL(31)
 
 struct range {
        u64 start;
@@ -120,6 +121,9 @@ struct intel_pt {
        bool sample_pebs;
        struct evsel *pebs_evsel;
 
+       u64 evt_sample_type;
+       u64 evt_id;
+
        u64 tsc_bit;
        u64 mtc_bit;
        u64 mtc_freq_bits;
@@ -2166,6 +2170,45 @@ static int intel_pt_synth_pebs_sample(struct intel_pt_queue *ptq)
        return err;
 }
 
+static int intel_pt_synth_events_sample(struct intel_pt_queue *ptq)
+{
+       struct intel_pt *pt = ptq->pt;
+       union perf_event *event = ptq->event_buf;
+       struct perf_sample sample = { .ip = 0, };
+       struct {
+               struct perf_synth_intel_evt cfe;
+               struct perf_synth_intel_evd evd[INTEL_PT_MAX_EVDS];
+       } raw;
+       int i;
+
+       if (intel_pt_skip_event(pt))
+               return 0;
+
+       intel_pt_prep_p_sample(pt, ptq, event, &sample);
+
+       sample.id        = ptq->pt->evt_id;
+       sample.stream_id = ptq->pt->evt_id;
+
+       raw.cfe.type     = ptq->state->cfe_type;
+       raw.cfe.reserved = 0;
+       raw.cfe.ip       = !!(ptq->state->flags & INTEL_PT_FUP_IP);
+       raw.cfe.vector   = ptq->state->cfe_vector;
+       raw.cfe.evd_cnt  = ptq->state->evd_cnt;
+
+       for (i = 0; i < ptq->state->evd_cnt; i++) {
+               raw.evd[i].et       = 0;
+               raw.evd[i].evd_type = ptq->state->evd[i].type;
+               raw.evd[i].payload  = ptq->state->evd[i].payload;
+       }
+
+       sample.raw_size = perf_synth__raw_size(raw) +
+                         ptq->state->evd_cnt * sizeof(struct perf_synth_intel_evd);
+       sample.raw_data = perf_synth__raw_data(&raw);
+
+       return intel_pt_deliver_synth_event(pt, event, &sample,
+                                           pt->evt_sample_type);
+}
+
 static int intel_pt_synth_error(struct intel_pt *pt, int code, int cpu,
                                pid_t pid, pid_t tid, u64 ip, u64 timestamp)
 {
@@ -2272,6 +2315,14 @@ static int intel_pt_sample(struct intel_pt_queue *ptq)
                        return err;
        }
 
+       if (pt->synth_opts.intr_events) {
+               if (state->type & INTEL_PT_EVT) {
+                       err = intel_pt_synth_events_sample(ptq);
+                       if (err)
+                               return err;
+               }
+       }
+
        if (pt->sample_pwr_events) {
                if (state->type & INTEL_PT_PSB_EVT) {
                        err = intel_pt_synth_psb_sample(ptq);
@@ -3469,6 +3520,17 @@ static int intel_pt_synth_events(struct intel_pt *pt,
                id += 1;
        }
 
+       if (pt->synth_opts.intr_events && (evsel->core.attr.config & INTEL_PT_CFG_EVT_EN)) {
+               attr.config = PERF_SYNTH_INTEL_EVT;
+               err = intel_pt_synth_event(session, "evt", &attr, id);
+               if (err)
+                       return err;
+               pt->evt_sample_type = attr.sample_type;
+               pt->evt_id = id;
+               intel_pt_set_event_name(evlist, id, "evt");
+               id += 1;
+       }
+
        return 0;
 }