perf tools: Add support for PERF_RECORD_AUX_OUTPUT_HW_ID

The PERF_RECORD_AUX_OUTPUT_HW_ID event provides a way to match AUX output
data like Intel PT PEBS-via-PT back to the event that it came from, by
providing a hardware ID that is present in the AUX output.

Reviewed-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org
Link: http://lore.kernel.org/lkml/20210907163903.11820-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/include/uapi/linux/perf_event.h

@@ -1141,6 +1141,21 @@ enum perf_event_type {
 	 */
 	PERF_RECORD_TEXT_POKE			= 20,
 
+	/*
+	 * Data written to the AUX area by hardware due to aux_output, may need
+	 * to be matched to the event by an architecture-specific hardware ID.
+	 * This records the hardware ID, but requires sample_id to provide the
+	 * event ID. e.g. Intel PT uses this record to disambiguate PEBS-via-PT
+	 * records from multiple events.
+	 *
+	 * struct {
+	 *	struct perf_event_header	header;
+	 *	u64				hw_id;
+	 *	struct sample_id		sample_id;
+	 * };
+	 */
+	PERF_RECORD_AUX_OUTPUT_HW_ID		= 21,
+
 	PERF_RECORD_MAX,			/* non-ABI */
 };
 

tools/lib/perf/include/perf/event.h

@@ -289,6 +289,11 @@ struct perf_record_itrace_start {
 	__u32			 tid;
 };
 
+struct perf_record_aux_output_hw_id {
+	struct perf_event_header header;
+	__u64			hw_id;
+};
+
 struct perf_record_thread_map_entry {
 	__u64			 pid;
 	char			 comm[16];
@@ -414,6 +419,7 @@ union perf_event {
 	struct perf_record_auxtrace_error	auxtrace_error;
 	struct perf_record_aux			aux;
 	struct perf_record_itrace_start		itrace_start;
+	struct perf_record_aux_output_hw_id	aux_output_hw_id;
 	struct perf_record_switch		context_switch;
 	struct perf_record_thread_map		thread_map;
 	struct perf_record_cpu_map		cpu_map;

tools/perf/builtin-inject.c

@@ -815,7 +815,8 @@ static int __cmd_inject(struct perf_inject *inject)
 		inject->tool.auxtrace_info  = perf_event__process_auxtrace_info;
 		inject->tool.auxtrace	    = perf_event__process_auxtrace;
 		inject->tool.aux	    = perf_event__drop_aux;
-		inject->tool.itrace_start   = perf_event__drop_aux,
+		inject->tool.itrace_start   = perf_event__drop_aux;
+		inject->tool.aux_output_hw_id = perf_event__drop_aux;
 		inject->tool.ordered_events = true;
 		inject->tool.ordering_requires_timestamps = true;
 		/* Allow space in the header for new attributes */
@@ -882,6 +883,7 @@ int cmd_inject(int argc, const char **argv)
 			.lost_samples	= perf_event__repipe,
 			.aux		= perf_event__repipe,
 			.itrace_start	= perf_event__repipe,
+			.aux_output_hw_id = perf_event__repipe,
 			.context_switch	= perf_event__repipe,
 			.throttle	= perf_event__repipe,
 			.unthrottle	= perf_event__repipe,

tools/perf/builtin-record.c

@@ -1411,7 +1411,7 @@ static int record__synthesize(struct record *rec, bool tail)
 		goto out;
 
 	/* Synthesize id_index before auxtrace_info */
-	if (rec->opts.auxtrace_sample_mode) {
+	if (rec->opts.auxtrace_sample_mode || rec->opts.full_auxtrace) {
 		err = perf_event__synthesize_id_index(tool,
 						      process_synthesized_event,
 						      session->evlist, machine);

tools/perf/util/event.c

@@ -57,6 +57,7 @@ static const char *perf_event__names[] = {
 	[PERF_RECORD_BPF_EVENT]			= "BPF_EVENT",
 	[PERF_RECORD_CGROUP]			= "CGROUP",
 	[PERF_RECORD_TEXT_POKE]			= "TEXT_POKE",
+	[PERF_RECORD_AUX_OUTPUT_HW_ID]		= "AUX_OUTPUT_HW_ID",
 	[PERF_RECORD_HEADER_ATTR]		= "ATTR",
 	[PERF_RECORD_HEADER_EVENT_TYPE]		= "EVENT_TYPE",
 	[PERF_RECORD_HEADER_TRACING_DATA]	= "TRACING_DATA",
@@ -237,6 +238,14 @@ int perf_event__process_itrace_start(struct perf_tool *tool __maybe_unused,
 	return machine__process_itrace_start_event(machine, event);
 }
 
+int perf_event__process_aux_output_hw_id(struct perf_tool *tool __maybe_unused,
+					 union perf_event *event,
+					 struct perf_sample *sample __maybe_unused,
+					 struct machine *machine)
+{
+	return machine__process_aux_output_hw_id_event(machine, event);
+}
+
 int perf_event__process_lost_samples(struct perf_tool *tool __maybe_unused,
 				     union perf_event *event,
 				     struct perf_sample *sample,
@@ -407,6 +416,12 @@ size_t perf_event__fprintf_itrace_start(union perf_event *event, FILE *fp)
 		       event->itrace_start.pid, event->itrace_start.tid);
 }
 
+size_t perf_event__fprintf_aux_output_hw_id(union perf_event *event, FILE *fp)
+{
+	return fprintf(fp, " hw_id: %#"PRI_lx64"\n",
+		       event->aux_output_hw_id.hw_id);
+}
+
 size_t perf_event__fprintf_switch(union perf_event *event, FILE *fp)
 {
 	bool out = event->header.misc & PERF_RECORD_MISC_SWITCH_OUT;
@@ -534,6 +549,9 @@ size_t perf_event__fprintf(union perf_event *event, struct machine *machine, FIL
 	case PERF_RECORD_TEXT_POKE:
 		ret += perf_event__fprintf_text_poke(event, machine, fp);
 		break;
+	case PERF_RECORD_AUX_OUTPUT_HW_ID:
+		ret += perf_event__fprintf_aux_output_hw_id(event, fp);
+		break;
 	default:
 		ret += fprintf(fp, "\n");
 	}

tools/perf/util/event.h

@@ -330,6 +330,10 @@ int perf_event__process_itrace_start(struct perf_tool *tool,
 				     union perf_event *event,
 				     struct perf_sample *sample,
 				     struct machine *machine);
+int perf_event__process_aux_output_hw_id(struct perf_tool *tool,
+					 union perf_event *event,
+					 struct perf_sample *sample,
+					 struct machine *machine);
 int perf_event__process_switch(struct perf_tool *tool,
 			       union perf_event *event,
 			       struct perf_sample *sample,
@@ -397,6 +401,7 @@ size_t perf_event__fprintf_mmap2(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_task(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_aux(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_itrace_start(union perf_event *event, FILE *fp);
+size_t perf_event__fprintf_aux_output_hw_id(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_switch(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_thread_map(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_cpu_map(union perf_event *event, FILE *fp);

tools/perf/util/machine.c

@@ -755,6 +755,14 @@ int machine__process_itrace_start_event(struct machine *machine __maybe_unused,
 	return 0;
 }
 
+int machine__process_aux_output_hw_id_event(struct machine *machine __maybe_unused,
+					    union perf_event *event)
+{
+	if (dump_trace)
+		perf_event__fprintf_aux_output_hw_id(event, stdout);
+	return 0;
+}
+
 int machine__process_switch_event(struct machine *machine __maybe_unused,
 				  union perf_event *event)
 {
@@ -2028,6 +2036,8 @@ int machine__process_event(struct machine *machine, union perf_event *event,
 		ret = machine__process_bpf(machine, event, sample); break;
 	case PERF_RECORD_TEXT_POKE:
 		ret = machine__process_text_poke(machine, event, sample); break;
+	case PERF_RECORD_AUX_OUTPUT_HW_ID:
+		ret = machine__process_aux_output_hw_id_event(machine, event); break;
 	default:
 		ret = -1;
 		break;

tools/perf/util/machine.h

@@ -124,6 +124,8 @@ int machine__process_aux_event(struct machine *machine,
 			       union perf_event *event);
 int machine__process_itrace_start_event(struct machine *machine,
 					union perf_event *event);
+int machine__process_aux_output_hw_id_event(struct machine *machine,
+					    union perf_event *event);
 int machine__process_switch_event(struct machine *machine,
 				  union perf_event *event);
 int machine__process_namespaces_event(struct machine *machine,

tools/perf/util/session.c

@@ -509,6 +509,8 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
 		tool->bpf = perf_event__process_bpf;
 	if (tool->text_poke == NULL)
 		tool->text_poke = perf_event__process_text_poke;
+	if (tool->aux_output_hw_id == NULL)
+		tool->aux_output_hw_id = perf_event__process_aux_output_hw_id;
 	if (tool->read == NULL)
 		tool->read = process_event_sample_stub;
 	if (tool->throttle == NULL)
@@ -1000,6 +1002,7 @@ static perf_event__swap_op perf_event__swap_ops[] = {
 	[PERF_RECORD_NAMESPACES]	  = perf_event__namespaces_swap,
 	[PERF_RECORD_CGROUP]		  = perf_event__cgroup_swap,
 	[PERF_RECORD_TEXT_POKE]		  = perf_event__text_poke_swap,
+	[PERF_RECORD_AUX_OUTPUT_HW_ID]	  = perf_event__all64_swap,
 	[PERF_RECORD_HEADER_ATTR]	  = perf_event__hdr_attr_swap,
 	[PERF_RECORD_HEADER_EVENT_TYPE]	  = perf_event__event_type_swap,
 	[PERF_RECORD_HEADER_TRACING_DATA] = perf_event__tracing_data_swap,
@@ -1556,6 +1559,8 @@ static int machines__deliver_event(struct machines *machines,
 		return tool->bpf(tool, event, sample, machine);
 	case PERF_RECORD_TEXT_POKE:
 		return tool->text_poke(tool, event, sample, machine);
+	case PERF_RECORD_AUX_OUTPUT_HW_ID:
+		return tool->aux_output_hw_id(tool, event, sample, machine);
 	default:
 		++evlist->stats.nr_unknown_events;
 		return -1;

tools/perf/util/tool.h

@@ -53,6 +53,7 @@ struct perf_tool {
 			lost_samples,
 			aux,
 			itrace_start,
+			aux_output_hw_id,
 			context_switch,
 			throttle,
 			unthrottle,