xref: /openbmc/linux/tools/perf/builtin-inject.c (revision 7adc363b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * builtin-inject.c
4  *
5  * Builtin inject command: Examine the live mode (stdin) event stream
6  * and repipe it to stdout while optionally injecting additional
7  * events into it.
8  */
9 #include "builtin.h"
10 
11 #include "util/color.h"
12 #include "util/dso.h"
13 #include "util/vdso.h"
14 #include "util/evlist.h"
15 #include "util/evsel.h"
16 #include "util/map.h"
17 #include "util/session.h"
18 #include "util/tool.h"
19 #include "util/debug.h"
20 #include "util/build-id.h"
21 #include "util/data.h"
22 #include "util/auxtrace.h"
23 #include "util/jit.h"
24 #include "util/string2.h"
25 #include "util/symbol.h"
26 #include "util/synthetic-events.h"
27 #include "util/thread.h"
28 #include "util/namespaces.h"
29 #include "util/util.h"
30 #include "util/tsc.h"
31 
32 #include <internal/lib.h>
33 
34 #include <linux/err.h>
35 #include <subcmd/parse-options.h>
36 #include <uapi/linux/mman.h> /* To get things like MAP_HUGETLB even on older libc headers */
37 
38 #include <linux/list.h>
39 #include <linux/string.h>
40 #include <linux/zalloc.h>
41 #include <linux/hash.h>
42 #include <ctype.h>
43 #include <errno.h>
44 #include <signal.h>
45 #include <inttypes.h>
46 
47 struct guest_event {
48 	struct perf_sample		sample;
49 	union perf_event		*event;
50 	char				*event_buf;
51 };
52 
53 struct guest_id {
54 	/* hlist_node must be first, see free_hlist() */
55 	struct hlist_node		node;
56 	u64				id;
57 	u64				host_id;
58 	u32				vcpu;
59 };
60 
61 struct guest_tid {
62 	/* hlist_node must be first, see free_hlist() */
63 	struct hlist_node		node;
64 	/* Thread ID of QEMU thread */
65 	u32				tid;
66 	u32				vcpu;
67 };
68 
69 struct guest_vcpu {
70 	/* Current host CPU */
71 	u32				cpu;
72 	/* Thread ID of QEMU thread */
73 	u32				tid;
74 };
75 
76 struct guest_session {
77 	char				*perf_data_file;
78 	u32				machine_pid;
79 	u64				time_offset;
80 	double				time_scale;
81 	struct perf_tool		tool;
82 	struct perf_data		data;
83 	struct perf_session		*session;
84 	char				*tmp_file_name;
85 	int				tmp_fd;
86 	struct perf_tsc_conversion	host_tc;
87 	struct perf_tsc_conversion	guest_tc;
88 	bool				copy_kcore_dir;
89 	bool				have_tc;
90 	bool				fetched;
91 	bool				ready;
92 	u16				dflt_id_hdr_size;
93 	u64				dflt_id;
94 	u64				highest_id;
95 	/* Array of guest_vcpu */
96 	struct guest_vcpu		*vcpu;
97 	size_t				vcpu_cnt;
98 	/* Hash table for guest_id */
99 	struct hlist_head		heads[PERF_EVLIST__HLIST_SIZE];
100 	/* Hash table for guest_tid */
101 	struct hlist_head		tids[PERF_EVLIST__HLIST_SIZE];
102 	/* Place to stash next guest event */
103 	struct guest_event		ev;
104 };
105 
106 struct perf_inject {
107 	struct perf_tool	tool;
108 	struct perf_session	*session;
109 	bool			build_ids;
110 	bool			build_id_all;
111 	bool			sched_stat;
112 	bool			have_auxtrace;
113 	bool			strip;
114 	bool			jit_mode;
115 	bool			in_place_update;
116 	bool			in_place_update_dry_run;
117 	bool			is_pipe;
118 	bool			copy_kcore_dir;
119 	const char		*input_name;
120 	struct perf_data	output;
121 	u64			bytes_written;
122 	u64			aux_id;
123 	struct list_head	samples;
124 	struct itrace_synth_opts itrace_synth_opts;
125 	char			*event_copy;
126 	struct perf_file_section secs[HEADER_FEAT_BITS];
127 	struct guest_session	guest_session;
128 	struct strlist		*known_build_ids;
129 };
130 
131 struct event_entry {
132 	struct list_head node;
133 	u32		 tid;
134 	union perf_event event[];
135 };
136 
137 static int dso__inject_build_id(struct dso *dso, struct perf_tool *tool,
138 				struct machine *machine, u8 cpumode, u32 flags);
139 
140 static int output_bytes(struct perf_inject *inject, void *buf, size_t sz)
141 {
142 	ssize_t size;
143 
144 	size = perf_data__write(&inject->output, buf, sz);
145 	if (size < 0)
146 		return -errno;
147 
148 	inject->bytes_written += size;
149 	return 0;
150 }
151 
152 static int perf_event__repipe_synth(struct perf_tool *tool,
153 				    union perf_event *event)
154 {
155 	struct perf_inject *inject = container_of(tool, struct perf_inject,
156 						  tool);
157 
158 	return output_bytes(inject, event, event->header.size);
159 }
160 
161 static int perf_event__repipe_oe_synth(struct perf_tool *tool,
162 				       union perf_event *event,
163 				       struct ordered_events *oe __maybe_unused)
164 {
165 	return perf_event__repipe_synth(tool, event);
166 }
167 
168 #ifdef HAVE_JITDUMP
169 static int perf_event__drop_oe(struct perf_tool *tool __maybe_unused,
170 			       union perf_event *event __maybe_unused,
171 			       struct ordered_events *oe __maybe_unused)
172 {
173 	return 0;
174 }
175 #endif
176 
177 static int perf_event__repipe_op2_synth(struct perf_session *session,
178 					union perf_event *event)
179 {
180 	return perf_event__repipe_synth(session->tool, event);
181 }
182 
183 static int perf_event__repipe_op4_synth(struct perf_session *session,
184 					union perf_event *event,
185 					u64 data __maybe_unused,
186 					const char *str __maybe_unused)
187 {
188 	return perf_event__repipe_synth(session->tool, event);
189 }
190 
191 static int perf_event__repipe_attr(struct perf_tool *tool,
192 				   union perf_event *event,
193 				   struct evlist **pevlist)
194 {
195 	struct perf_inject *inject = container_of(tool, struct perf_inject,
196 						  tool);
197 	int ret;
198 
199 	ret = perf_event__process_attr(tool, event, pevlist);
200 	if (ret)
201 		return ret;
202 
203 	if (!inject->is_pipe)
204 		return 0;
205 
206 	return perf_event__repipe_synth(tool, event);
207 }
208 
209 static int perf_event__repipe_event_update(struct perf_tool *tool,
210 					   union perf_event *event,
211 					   struct evlist **pevlist __maybe_unused)
212 {
213 	return perf_event__repipe_synth(tool, event);
214 }
215 
216 #ifdef HAVE_AUXTRACE_SUPPORT
217 
218 static int copy_bytes(struct perf_inject *inject, struct perf_data *data, off_t size)
219 {
220 	char buf[4096];
221 	ssize_t ssz;
222 	int ret;
223 
224 	while (size > 0) {
225 		ssz = perf_data__read(data, buf, min(size, (off_t)sizeof(buf)));
226 		if (ssz < 0)
227 			return -errno;
228 		ret = output_bytes(inject, buf, ssz);
229 		if (ret)
230 			return ret;
231 		size -= ssz;
232 	}
233 
234 	return 0;
235 }
236 
237 static s64 perf_event__repipe_auxtrace(struct perf_session *session,
238 				       union perf_event *event)
239 {
240 	struct perf_tool *tool = session->tool;
241 	struct perf_inject *inject = container_of(tool, struct perf_inject,
242 						  tool);
243 	int ret;
244 
245 	inject->have_auxtrace = true;
246 
247 	if (!inject->output.is_pipe) {
248 		off_t offset;
249 
250 		offset = lseek(inject->output.file.fd, 0, SEEK_CUR);
251 		if (offset == -1)
252 			return -errno;
253 		ret = auxtrace_index__auxtrace_event(&session->auxtrace_index,
254 						     event, offset);
255 		if (ret < 0)
256 			return ret;
257 	}
258 
259 	if (perf_data__is_pipe(session->data) || !session->one_mmap) {
260 		ret = output_bytes(inject, event, event->header.size);
261 		if (ret < 0)
262 			return ret;
263 		ret = copy_bytes(inject, session->data,
264 				 event->auxtrace.size);
265 	} else {
266 		ret = output_bytes(inject, event,
267 				   event->header.size + event->auxtrace.size);
268 	}
269 	if (ret < 0)
270 		return ret;
271 
272 	return event->auxtrace.size;
273 }
274 
275 #else
276 
277 static s64
278 perf_event__repipe_auxtrace(struct perf_session *session __maybe_unused,
279 			    union perf_event *event __maybe_unused)
280 {
281 	pr_err("AUX area tracing not supported\n");
282 	return -EINVAL;
283 }
284 
285 #endif
286 
287 static int perf_event__repipe(struct perf_tool *tool,
288 			      union perf_event *event,
289 			      struct perf_sample *sample __maybe_unused,
290 			      struct machine *machine __maybe_unused)
291 {
292 	return perf_event__repipe_synth(tool, event);
293 }
294 
295 static int perf_event__drop(struct perf_tool *tool __maybe_unused,
296 			    union perf_event *event __maybe_unused,
297 			    struct perf_sample *sample __maybe_unused,
298 			    struct machine *machine __maybe_unused)
299 {
300 	return 0;
301 }
302 
303 static int perf_event__drop_aux(struct perf_tool *tool,
304 				union perf_event *event __maybe_unused,
305 				struct perf_sample *sample,
306 				struct machine *machine __maybe_unused)
307 {
308 	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
309 
310 	if (!inject->aux_id)
311 		inject->aux_id = sample->id;
312 
313 	return 0;
314 }
315 
316 static union perf_event *
317 perf_inject__cut_auxtrace_sample(struct perf_inject *inject,
318 				 union perf_event *event,
319 				 struct perf_sample *sample)
320 {
321 	size_t sz1 = sample->aux_sample.data - (void *)event;
322 	size_t sz2 = event->header.size - sample->aux_sample.size - sz1;
323 	union perf_event *ev;
324 
325 	if (inject->event_copy == NULL) {
326 		inject->event_copy = malloc(PERF_SAMPLE_MAX_SIZE);
327 		if (!inject->event_copy)
328 			return ERR_PTR(-ENOMEM);
329 	}
330 	ev = (union perf_event *)inject->event_copy;
331 	if (sz1 > event->header.size || sz2 > event->header.size ||
332 	    sz1 + sz2 > event->header.size ||
333 	    sz1 < sizeof(struct perf_event_header) + sizeof(u64))
334 		return event;
335 
336 	memcpy(ev, event, sz1);
337 	memcpy((void *)ev + sz1, (void *)event + event->header.size - sz2, sz2);
338 	ev->header.size = sz1 + sz2;
339 	((u64 *)((void *)ev + sz1))[-1] = 0;
340 
341 	return ev;
342 }
343 
344 typedef int (*inject_handler)(struct perf_tool *tool,
345 			      union perf_event *event,
346 			      struct perf_sample *sample,
347 			      struct evsel *evsel,
348 			      struct machine *machine);
349 
350 static int perf_event__repipe_sample(struct perf_tool *tool,
351 				     union perf_event *event,
352 				     struct perf_sample *sample,
353 				     struct evsel *evsel,
354 				     struct machine *machine)
355 {
356 	struct perf_inject *inject = container_of(tool, struct perf_inject,
357 						  tool);
358 
359 	if (evsel && evsel->handler) {
360 		inject_handler f = evsel->handler;
361 		return f(tool, event, sample, evsel, machine);
362 	}
363 
364 	build_id__mark_dso_hit(tool, event, sample, evsel, machine);
365 
366 	if (inject->itrace_synth_opts.set && sample->aux_sample.size) {
367 		event = perf_inject__cut_auxtrace_sample(inject, event, sample);
368 		if (IS_ERR(event))
369 			return PTR_ERR(event);
370 	}
371 
372 	return perf_event__repipe_synth(tool, event);
373 }
374 
375 static int perf_event__repipe_mmap(struct perf_tool *tool,
376 				   union perf_event *event,
377 				   struct perf_sample *sample,
378 				   struct machine *machine)
379 {
380 	int err;
381 
382 	err = perf_event__process_mmap(tool, event, sample, machine);
383 	perf_event__repipe(tool, event, sample, machine);
384 
385 	return err;
386 }
387 
388 #ifdef HAVE_JITDUMP
389 static int perf_event__jit_repipe_mmap(struct perf_tool *tool,
390 				       union perf_event *event,
391 				       struct perf_sample *sample,
392 				       struct machine *machine)
393 {
394 	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
395 	u64 n = 0;
396 	int ret;
397 
398 	/*
399 	 * if jit marker, then inject jit mmaps and generate ELF images
400 	 */
401 	ret = jit_process(inject->session, &inject->output, machine,
402 			  event->mmap.filename, event->mmap.pid, event->mmap.tid, &n);
403 	if (ret < 0)
404 		return ret;
405 	if (ret) {
406 		inject->bytes_written += n;
407 		return 0;
408 	}
409 	return perf_event__repipe_mmap(tool, event, sample, machine);
410 }
411 #endif
412 
413 static struct dso *findnew_dso(int pid, int tid, const char *filename,
414 			       struct dso_id *id, struct machine *machine)
415 {
416 	struct thread *thread;
417 	struct nsinfo *nsi = NULL;
418 	struct nsinfo *nnsi;
419 	struct dso *dso;
420 	bool vdso;
421 
422 	thread = machine__findnew_thread(machine, pid, tid);
423 	if (thread == NULL) {
424 		pr_err("cannot find or create a task %d/%d.\n", tid, pid);
425 		return NULL;
426 	}
427 
428 	vdso = is_vdso_map(filename);
429 	nsi = nsinfo__get(thread__nsinfo(thread));
430 
431 	if (vdso) {
432 		/* The vdso maps are always on the host and not the
433 		 * container.  Ensure that we don't use setns to look
434 		 * them up.
435 		 */
436 		nnsi = nsinfo__copy(nsi);
437 		if (nnsi) {
438 			nsinfo__put(nsi);
439 			nsinfo__clear_need_setns(nnsi);
440 			nsi = nnsi;
441 		}
442 		dso = machine__findnew_vdso(machine, thread);
443 	} else {
444 		dso = machine__findnew_dso_id(machine, filename, id);
445 	}
446 
447 	if (dso) {
448 		mutex_lock(&dso->lock);
449 		nsinfo__put(dso->nsinfo);
450 		dso->nsinfo = nsi;
451 		mutex_unlock(&dso->lock);
452 	} else
453 		nsinfo__put(nsi);
454 
455 	thread__put(thread);
456 	return dso;
457 }
458 
459 static int perf_event__repipe_buildid_mmap(struct perf_tool *tool,
460 					   union perf_event *event,
461 					   struct perf_sample *sample,
462 					   struct machine *machine)
463 {
464 	struct dso *dso;
465 
466 	dso = findnew_dso(event->mmap.pid, event->mmap.tid,
467 			  event->mmap.filename, NULL, machine);
468 
469 	if (dso && !dso->hit) {
470 		dso->hit = 1;
471 		dso__inject_build_id(dso, tool, machine, sample->cpumode, 0);
472 	}
473 	dso__put(dso);
474 
475 	return perf_event__repipe(tool, event, sample, machine);
476 }
477 
478 static int perf_event__repipe_mmap2(struct perf_tool *tool,
479 				   union perf_event *event,
480 				   struct perf_sample *sample,
481 				   struct machine *machine)
482 {
483 	int err;
484 
485 	err = perf_event__process_mmap2(tool, event, sample, machine);
486 	perf_event__repipe(tool, event, sample, machine);
487 
488 	if (event->header.misc & PERF_RECORD_MISC_MMAP_BUILD_ID) {
489 		struct dso *dso;
490 
491 		dso = findnew_dso(event->mmap2.pid, event->mmap2.tid,
492 				  event->mmap2.filename, NULL, machine);
493 		if (dso) {
494 			/* mark it not to inject build-id */
495 			dso->hit = 1;
496 		}
497 		dso__put(dso);
498 	}
499 
500 	return err;
501 }
502 
503 #ifdef HAVE_JITDUMP
504 static int perf_event__jit_repipe_mmap2(struct perf_tool *tool,
505 					union perf_event *event,
506 					struct perf_sample *sample,
507 					struct machine *machine)
508 {
509 	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
510 	u64 n = 0;
511 	int ret;
512 
513 	/*
514 	 * if jit marker, then inject jit mmaps and generate ELF images
515 	 */
516 	ret = jit_process(inject->session, &inject->output, machine,
517 			  event->mmap2.filename, event->mmap2.pid, event->mmap2.tid, &n);
518 	if (ret < 0)
519 		return ret;
520 	if (ret) {
521 		inject->bytes_written += n;
522 		return 0;
523 	}
524 	return perf_event__repipe_mmap2(tool, event, sample, machine);
525 }
526 #endif
527 
528 static int perf_event__repipe_buildid_mmap2(struct perf_tool *tool,
529 					    union perf_event *event,
530 					    struct perf_sample *sample,
531 					    struct machine *machine)
532 {
533 	struct dso_id dso_id = {
534 		.maj = event->mmap2.maj,
535 		.min = event->mmap2.min,
536 		.ino = event->mmap2.ino,
537 		.ino_generation = event->mmap2.ino_generation,
538 	};
539 	struct dso *dso;
540 
541 	if (event->header.misc & PERF_RECORD_MISC_MMAP_BUILD_ID) {
542 		/* cannot use dso_id since it'd have invalid info */
543 		dso = findnew_dso(event->mmap2.pid, event->mmap2.tid,
544 				  event->mmap2.filename, NULL, machine);
545 		if (dso) {
546 			/* mark it not to inject build-id */
547 			dso->hit = 1;
548 		}
549 		dso__put(dso);
550 		perf_event__repipe(tool, event, sample, machine);
551 		return 0;
552 	}
553 
554 	dso = findnew_dso(event->mmap2.pid, event->mmap2.tid,
555 			  event->mmap2.filename, &dso_id, machine);
556 
557 	if (dso && !dso->hit) {
558 		dso->hit = 1;
559 		dso__inject_build_id(dso, tool, machine, sample->cpumode,
560 				     event->mmap2.flags);
561 	}
562 	dso__put(dso);
563 
564 	perf_event__repipe(tool, event, sample, machine);
565 
566 	return 0;
567 }
568 
569 static int perf_event__repipe_fork(struct perf_tool *tool,
570 				   union perf_event *event,
571 				   struct perf_sample *sample,
572 				   struct machine *machine)
573 {
574 	int err;
575 
576 	err = perf_event__process_fork(tool, event, sample, machine);
577 	perf_event__repipe(tool, event, sample, machine);
578 
579 	return err;
580 }
581 
582 static int perf_event__repipe_comm(struct perf_tool *tool,
583 				   union perf_event *event,
584 				   struct perf_sample *sample,
585 				   struct machine *machine)
586 {
587 	int err;
588 
589 	err = perf_event__process_comm(tool, event, sample, machine);
590 	perf_event__repipe(tool, event, sample, machine);
591 
592 	return err;
593 }
594 
595 static int perf_event__repipe_namespaces(struct perf_tool *tool,
596 					 union perf_event *event,
597 					 struct perf_sample *sample,
598 					 struct machine *machine)
599 {
600 	int err = perf_event__process_namespaces(tool, event, sample, machine);
601 
602 	perf_event__repipe(tool, event, sample, machine);
603 
604 	return err;
605 }
606 
607 static int perf_event__repipe_exit(struct perf_tool *tool,
608 				   union perf_event *event,
609 				   struct perf_sample *sample,
610 				   struct machine *machine)
611 {
612 	int err;
613 
614 	err = perf_event__process_exit(tool, event, sample, machine);
615 	perf_event__repipe(tool, event, sample, machine);
616 
617 	return err;
618 }
619 
620 #ifdef HAVE_LIBTRACEEVENT
621 static int perf_event__repipe_tracing_data(struct perf_session *session,
622 					   union perf_event *event)
623 {
624 	perf_event__repipe_synth(session->tool, event);
625 
626 	return perf_event__process_tracing_data(session, event);
627 }
628 #endif
629 
630 static int dso__read_build_id(struct dso *dso)
631 {
632 	struct nscookie nsc;
633 
634 	if (dso->has_build_id)
635 		return 0;
636 
637 	mutex_lock(&dso->lock);
638 	nsinfo__mountns_enter(dso->nsinfo, &nsc);
639 	if (filename__read_build_id(dso->long_name, &dso->bid) > 0)
640 		dso->has_build_id = true;
641 	else if (dso->nsinfo) {
642 		char *new_name = dso__filename_with_chroot(dso, dso->long_name);
643 
644 		if (new_name && filename__read_build_id(new_name, &dso->bid) > 0)
645 			dso->has_build_id = true;
646 		free(new_name);
647 	}
648 	nsinfo__mountns_exit(&nsc);
649 	mutex_unlock(&dso->lock);
650 
651 	return dso->has_build_id ? 0 : -1;
652 }
653 
654 static struct strlist *perf_inject__parse_known_build_ids(
655 	const char *known_build_ids_string)
656 {
657 	struct str_node *pos, *tmp;
658 	struct strlist *known_build_ids;
659 	int bid_len;
660 
661 	known_build_ids = strlist__new(known_build_ids_string, NULL);
662 	if (known_build_ids == NULL)
663 		return NULL;
664 	strlist__for_each_entry_safe(pos, tmp, known_build_ids) {
665 		const char *build_id, *dso_name;
666 
667 		build_id = skip_spaces(pos->s);
668 		dso_name = strchr(build_id, ' ');
669 		if (dso_name == NULL) {
670 			strlist__remove(known_build_ids, pos);
671 			continue;
672 		}
673 		bid_len = dso_name - pos->s;
674 		dso_name = skip_spaces(dso_name);
675 		if (bid_len % 2 != 0 || bid_len >= SBUILD_ID_SIZE) {
676 			strlist__remove(known_build_ids, pos);
677 			continue;
678 		}
679 		for (int ix = 0; 2 * ix + 1 < bid_len; ++ix) {
680 			if (!isxdigit(build_id[2 * ix]) ||
681 			    !isxdigit(build_id[2 * ix + 1])) {
682 				strlist__remove(known_build_ids, pos);
683 				break;
684 			}
685 		}
686 	}
687 	return known_build_ids;
688 }
689 
690 static bool perf_inject__lookup_known_build_id(struct perf_inject *inject,
691 					       struct dso *dso)
692 {
693 	struct str_node *pos;
694 	int bid_len;
695 
696 	strlist__for_each_entry(pos, inject->known_build_ids) {
697 		const char *build_id, *dso_name;
698 
699 		build_id = skip_spaces(pos->s);
700 		dso_name = strchr(build_id, ' ');
701 		bid_len = dso_name - pos->s;
702 		dso_name = skip_spaces(dso_name);
703 		if (strcmp(dso->long_name, dso_name))
704 			continue;
705 		for (int ix = 0; 2 * ix + 1 < bid_len; ++ix) {
706 			dso->bid.data[ix] = (hex(build_id[2 * ix]) << 4 |
707 					     hex(build_id[2 * ix + 1]));
708 		}
709 		dso->bid.size = bid_len / 2;
710 		dso->has_build_id = 1;
711 		return true;
712 	}
713 	return false;
714 }
715 
716 static int dso__inject_build_id(struct dso *dso, struct perf_tool *tool,
717 				struct machine *machine, u8 cpumode, u32 flags)
718 {
719 	struct perf_inject *inject = container_of(tool, struct perf_inject,
720 						  tool);
721 	int err;
722 
723 	if (is_anon_memory(dso->long_name) || flags & MAP_HUGETLB)
724 		return 0;
725 	if (is_no_dso_memory(dso->long_name))
726 		return 0;
727 
728 	if (inject->known_build_ids != NULL &&
729 	    perf_inject__lookup_known_build_id(inject, dso))
730 		return 1;
731 
732 	if (dso__read_build_id(dso) < 0) {
733 		pr_debug("no build_id found for %s\n", dso->long_name);
734 		return -1;
735 	}
736 
737 	err = perf_event__synthesize_build_id(tool, dso, cpumode,
738 					      perf_event__repipe, machine);
739 	if (err) {
740 		pr_err("Can't synthesize build_id event for %s\n", dso->long_name);
741 		return -1;
742 	}
743 
744 	return 0;
745 }
746 
747 int perf_event__inject_buildid(struct perf_tool *tool, union perf_event *event,
748 			       struct perf_sample *sample,
749 			       struct evsel *evsel __maybe_unused,
750 			       struct machine *machine)
751 {
752 	struct addr_location al;
753 	struct thread *thread;
754 
755 	addr_location__init(&al);
756 	thread = machine__findnew_thread(machine, sample->pid, sample->tid);
757 	if (thread == NULL) {
758 		pr_err("problem processing %d event, skipping it.\n",
759 		       event->header.type);
760 		goto repipe;
761 	}
762 
763 	if (thread__find_map(thread, sample->cpumode, sample->ip, &al)) {
764 		struct dso *dso = map__dso(al.map);
765 
766 		if (!dso->hit) {
767 			dso->hit = 1;
768 			dso__inject_build_id(dso, tool, machine,
769 					     sample->cpumode, map__flags(al.map));
770 		}
771 	}
772 
773 	thread__put(thread);
774 repipe:
775 	perf_event__repipe(tool, event, sample, machine);
776 	addr_location__exit(&al);
777 	return 0;
778 }
779 
780 static int perf_inject__sched_process_exit(struct perf_tool *tool,
781 					   union perf_event *event __maybe_unused,
782 					   struct perf_sample *sample,
783 					   struct evsel *evsel __maybe_unused,
784 					   struct machine *machine __maybe_unused)
785 {
786 	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
787 	struct event_entry *ent;
788 
789 	list_for_each_entry(ent, &inject->samples, node) {
790 		if (sample->tid == ent->tid) {
791 			list_del_init(&ent->node);
792 			free(ent);
793 			break;
794 		}
795 	}
796 
797 	return 0;
798 }
799 
800 static int perf_inject__sched_switch(struct perf_tool *tool,
801 				     union perf_event *event,
802 				     struct perf_sample *sample,
803 				     struct evsel *evsel,
804 				     struct machine *machine)
805 {
806 	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
807 	struct event_entry *ent;
808 
809 	perf_inject__sched_process_exit(tool, event, sample, evsel, machine);
810 
811 	ent = malloc(event->header.size + sizeof(struct event_entry));
812 	if (ent == NULL) {
813 		color_fprintf(stderr, PERF_COLOR_RED,
814 			     "Not enough memory to process sched switch event!");
815 		return -1;
816 	}
817 
818 	ent->tid = sample->tid;
819 	memcpy(&ent->event, event, event->header.size);
820 	list_add(&ent->node, &inject->samples);
821 	return 0;
822 }
823 
824 #ifdef HAVE_LIBTRACEEVENT
825 static int perf_inject__sched_stat(struct perf_tool *tool,
826 				   union perf_event *event __maybe_unused,
827 				   struct perf_sample *sample,
828 				   struct evsel *evsel,
829 				   struct machine *machine)
830 {
831 	struct event_entry *ent;
832 	union perf_event *event_sw;
833 	struct perf_sample sample_sw;
834 	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
835 	u32 pid = evsel__intval(evsel, sample, "pid");
836 
837 	list_for_each_entry(ent, &inject->samples, node) {
838 		if (pid == ent->tid)
839 			goto found;
840 	}
841 
842 	return 0;
843 found:
844 	event_sw = &ent->event[0];
845 	evsel__parse_sample(evsel, event_sw, &sample_sw);
846 
847 	sample_sw.period = sample->period;
848 	sample_sw.time	 = sample->time;
849 	perf_event__synthesize_sample(event_sw, evsel->core.attr.sample_type,
850 				      evsel->core.attr.read_format, &sample_sw);
851 	build_id__mark_dso_hit(tool, event_sw, &sample_sw, evsel, machine);
852 	return perf_event__repipe(tool, event_sw, &sample_sw, machine);
853 }
854 #endif
855 
856 static struct guest_vcpu *guest_session__vcpu(struct guest_session *gs, u32 vcpu)
857 {
858 	if (realloc_array_as_needed(gs->vcpu, gs->vcpu_cnt, vcpu, NULL))
859 		return NULL;
860 	return &gs->vcpu[vcpu];
861 }
862 
863 static int guest_session__output_bytes(struct guest_session *gs, void *buf, size_t sz)
864 {
865 	ssize_t ret = writen(gs->tmp_fd, buf, sz);
866 
867 	return ret < 0 ? ret : 0;
868 }
869 
870 static int guest_session__repipe(struct perf_tool *tool,
871 				 union perf_event *event,
872 				 struct perf_sample *sample __maybe_unused,
873 				 struct machine *machine __maybe_unused)
874 {
875 	struct guest_session *gs = container_of(tool, struct guest_session, tool);
876 
877 	return guest_session__output_bytes(gs, event, event->header.size);
878 }
879 
880 static int guest_session__map_tid(struct guest_session *gs, u32 tid, u32 vcpu)
881 {
882 	struct guest_tid *guest_tid = zalloc(sizeof(*guest_tid));
883 	int hash;
884 
885 	if (!guest_tid)
886 		return -ENOMEM;
887 
888 	guest_tid->tid = tid;
889 	guest_tid->vcpu = vcpu;
890 	hash = hash_32(guest_tid->tid, PERF_EVLIST__HLIST_BITS);
891 	hlist_add_head(&guest_tid->node, &gs->tids[hash]);
892 
893 	return 0;
894 }
895 
896 static int host_peek_vm_comms_cb(struct perf_session *session __maybe_unused,
897 				 union perf_event *event,
898 				 u64 offset __maybe_unused, void *data)
899 {
900 	struct guest_session *gs = data;
901 	unsigned int vcpu;
902 	struct guest_vcpu *guest_vcpu;
903 	int ret;
904 
905 	if (event->header.type != PERF_RECORD_COMM ||
906 	    event->comm.pid != gs->machine_pid)
907 		return 0;
908 
909 	/*
910 	 * QEMU option -name debug-threads=on, causes thread names formatted as
911 	 * below, although it is not an ABI. Also libvirt seems to use this by
912 	 * default. Here we rely on it to tell us which thread is which VCPU.
913 	 */
914 	ret = sscanf(event->comm.comm, "CPU %u/KVM", &vcpu);
915 	if (ret <= 0)
916 		return ret;
917 	pr_debug("Found VCPU: tid %u comm %s vcpu %u\n",
918 		 event->comm.tid, event->comm.comm, vcpu);
919 	if (vcpu > INT_MAX) {
920 		pr_err("Invalid VCPU %u\n", vcpu);
921 		return -EINVAL;
922 	}
923 	guest_vcpu = guest_session__vcpu(gs, vcpu);
924 	if (!guest_vcpu)
925 		return -ENOMEM;
926 	if (guest_vcpu->tid && guest_vcpu->tid != event->comm.tid) {
927 		pr_err("Fatal error: Two threads found with the same VCPU\n");
928 		return -EINVAL;
929 	}
930 	guest_vcpu->tid = event->comm.tid;
931 
932 	return guest_session__map_tid(gs, event->comm.tid, vcpu);
933 }
934 
935 static int host_peek_vm_comms(struct perf_session *session, struct guest_session *gs)
936 {
937 	return perf_session__peek_events(session, session->header.data_offset,
938 					 session->header.data_size,
939 					 host_peek_vm_comms_cb, gs);
940 }
941 
942 static bool evlist__is_id_used(struct evlist *evlist, u64 id)
943 {
944 	return evlist__id2sid(evlist, id);
945 }
946 
947 static u64 guest_session__allocate_new_id(struct guest_session *gs, struct evlist *host_evlist)
948 {
949 	do {
950 		gs->highest_id += 1;
951 	} while (!gs->highest_id || evlist__is_id_used(host_evlist, gs->highest_id));
952 
953 	return gs->highest_id;
954 }
955 
956 static int guest_session__map_id(struct guest_session *gs, u64 id, u64 host_id, u32 vcpu)
957 {
958 	struct guest_id *guest_id = zalloc(sizeof(*guest_id));
959 	int hash;
960 
961 	if (!guest_id)
962 		return -ENOMEM;
963 
964 	guest_id->id = id;
965 	guest_id->host_id = host_id;
966 	guest_id->vcpu = vcpu;
967 	hash = hash_64(guest_id->id, PERF_EVLIST__HLIST_BITS);
968 	hlist_add_head(&guest_id->node, &gs->heads[hash]);
969 
970 	return 0;
971 }
972 
973 static u64 evlist__find_highest_id(struct evlist *evlist)
974 {
975 	struct evsel *evsel;
976 	u64 highest_id = 1;
977 
978 	evlist__for_each_entry(evlist, evsel) {
979 		u32 j;
980 
981 		for (j = 0; j < evsel->core.ids; j++) {
982 			u64 id = evsel->core.id[j];
983 
984 			if (id > highest_id)
985 				highest_id = id;
986 		}
987 	}
988 
989 	return highest_id;
990 }
991 
992 static int guest_session__map_ids(struct guest_session *gs, struct evlist *host_evlist)
993 {
994 	struct evlist *evlist = gs->session->evlist;
995 	struct evsel *evsel;
996 	int ret;
997 
998 	evlist__for_each_entry(evlist, evsel) {
999 		u32 j;
1000 
1001 		for (j = 0; j < evsel->core.ids; j++) {
1002 			struct perf_sample_id *sid;
1003 			u64 host_id;
1004 			u64 id;
1005 
1006 			id = evsel->core.id[j];
1007 			sid = evlist__id2sid(evlist, id);
1008 			if (!sid || sid->cpu.cpu == -1)
1009 				continue;
1010 			host_id = guest_session__allocate_new_id(gs, host_evlist);
1011 			ret = guest_session__map_id(gs, id, host_id, sid->cpu.cpu);
1012 			if (ret)
1013 				return ret;
1014 		}
1015 	}
1016 
1017 	return 0;
1018 }
1019 
1020 static struct guest_id *guest_session__lookup_id(struct guest_session *gs, u64 id)
1021 {
1022 	struct hlist_head *head;
1023 	struct guest_id *guest_id;
1024 	int hash;
1025 
1026 	hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
1027 	head = &gs->heads[hash];
1028 
1029 	hlist_for_each_entry(guest_id, head, node)
1030 		if (guest_id->id == id)
1031 			return guest_id;
1032 
1033 	return NULL;
1034 }
1035 
1036 static int process_attr(struct perf_tool *tool, union perf_event *event,
1037 			struct perf_sample *sample __maybe_unused,
1038 			struct machine *machine __maybe_unused)
1039 {
1040 	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
1041 
1042 	return perf_event__process_attr(tool, event, &inject->session->evlist);
1043 }
1044 
1045 static int guest_session__add_attr(struct guest_session *gs, struct evsel *evsel)
1046 {
1047 	struct perf_inject *inject = container_of(gs, struct perf_inject, guest_session);
1048 	struct perf_event_attr attr = evsel->core.attr;
1049 	u64 *id_array;
1050 	u32 *vcpu_array;
1051 	int ret = -ENOMEM;
1052 	u32 i;
1053 
1054 	id_array = calloc(evsel->core.ids, sizeof(*id_array));
1055 	if (!id_array)
1056 		return -ENOMEM;
1057 
1058 	vcpu_array = calloc(evsel->core.ids, sizeof(*vcpu_array));
1059 	if (!vcpu_array)
1060 		goto out;
1061 
1062 	for (i = 0; i < evsel->core.ids; i++) {
1063 		u64 id = evsel->core.id[i];
1064 		struct guest_id *guest_id = guest_session__lookup_id(gs, id);
1065 
1066 		if (!guest_id) {
1067 			pr_err("Failed to find guest id %"PRIu64"\n", id);
1068 			ret = -EINVAL;
1069 			goto out;
1070 		}
1071 		id_array[i] = guest_id->host_id;
1072 		vcpu_array[i] = guest_id->vcpu;
1073 	}
1074 
1075 	attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
1076 	attr.exclude_host = 1;
1077 	attr.exclude_guest = 0;
1078 
1079 	ret = perf_event__synthesize_attr(&inject->tool, &attr, evsel->core.ids,
1080 					  id_array, process_attr);
1081 	if (ret)
1082 		pr_err("Failed to add guest attr.\n");
1083 
1084 	for (i = 0; i < evsel->core.ids; i++) {
1085 		struct perf_sample_id *sid;
1086 		u32 vcpu = vcpu_array[i];
1087 
1088 		sid = evlist__id2sid(inject->session->evlist, id_array[i]);
1089 		/* Guest event is per-thread from the host point of view */
1090 		sid->cpu.cpu = -1;
1091 		sid->tid = gs->vcpu[vcpu].tid;
1092 		sid->machine_pid = gs->machine_pid;
1093 		sid->vcpu.cpu = vcpu;
1094 	}
1095 out:
1096 	free(vcpu_array);
1097 	free(id_array);
1098 	return ret;
1099 }
1100 
1101 static int guest_session__add_attrs(struct guest_session *gs)
1102 {
1103 	struct evlist *evlist = gs->session->evlist;
1104 	struct evsel *evsel;
1105 	int ret;
1106 
1107 	evlist__for_each_entry(evlist, evsel) {
1108 		ret = guest_session__add_attr(gs, evsel);
1109 		if (ret)
1110 			return ret;
1111 	}
1112 
1113 	return 0;
1114 }
1115 
1116 static int synthesize_id_index(struct perf_inject *inject, size_t new_cnt)
1117 {
1118 	struct perf_session *session = inject->session;
1119 	struct evlist *evlist = session->evlist;
1120 	struct machine *machine = &session->machines.host;
1121 	size_t from = evlist->core.nr_entries - new_cnt;
1122 
1123 	return __perf_event__synthesize_id_index(&inject->tool, perf_event__repipe,
1124 						 evlist, machine, from);
1125 }
1126 
1127 static struct guest_tid *guest_session__lookup_tid(struct guest_session *gs, u32 tid)
1128 {
1129 	struct hlist_head *head;
1130 	struct guest_tid *guest_tid;
1131 	int hash;
1132 
1133 	hash = hash_32(tid, PERF_EVLIST__HLIST_BITS);
1134 	head = &gs->tids[hash];
1135 
1136 	hlist_for_each_entry(guest_tid, head, node)
1137 		if (guest_tid->tid == tid)
1138 			return guest_tid;
1139 
1140 	return NULL;
1141 }
1142 
1143 static bool dso__is_in_kernel_space(struct dso *dso)
1144 {
1145 	if (dso__is_vdso(dso))
1146 		return false;
1147 
1148 	return dso__is_kcore(dso) ||
1149 	       dso->kernel ||
1150 	       is_kernel_module(dso->long_name, PERF_RECORD_MISC_CPUMODE_UNKNOWN);
1151 }
1152 
1153 static u64 evlist__first_id(struct evlist *evlist)
1154 {
1155 	struct evsel *evsel;
1156 
1157 	evlist__for_each_entry(evlist, evsel) {
1158 		if (evsel->core.ids)
1159 			return evsel->core.id[0];
1160 	}
1161 	return 0;
1162 }
1163 
1164 static int process_build_id(struct perf_tool *tool,
1165 			    union perf_event *event,
1166 			    struct perf_sample *sample __maybe_unused,
1167 			    struct machine *machine __maybe_unused)
1168 {
1169 	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
1170 
1171 	return perf_event__process_build_id(inject->session, event);
1172 }
1173 
1174 static int synthesize_build_id(struct perf_inject *inject, struct dso *dso, pid_t machine_pid)
1175 {
1176 	struct machine *machine = perf_session__findnew_machine(inject->session, machine_pid);
1177 	u8 cpumode = dso__is_in_kernel_space(dso) ?
1178 			PERF_RECORD_MISC_GUEST_KERNEL :
1179 			PERF_RECORD_MISC_GUEST_USER;
1180 
1181 	if (!machine)
1182 		return -ENOMEM;
1183 
1184 	dso->hit = 1;
1185 
1186 	return perf_event__synthesize_build_id(&inject->tool, dso, cpumode,
1187 					       process_build_id, machine);
1188 }
1189 
1190 static int guest_session__add_build_ids(struct guest_session *gs)
1191 {
1192 	struct perf_inject *inject = container_of(gs, struct perf_inject, guest_session);
1193 	struct machine *machine = &gs->session->machines.host;
1194 	struct dso *dso;
1195 	int ret;
1196 
1197 	/* Build IDs will be put in the Build ID feature section */
1198 	perf_header__set_feat(&inject->session->header, HEADER_BUILD_ID);
1199 
1200 	dsos__for_each_with_build_id(dso, &machine->dsos.head) {
1201 		ret = synthesize_build_id(inject, dso, gs->machine_pid);
1202 		if (ret)
1203 			return ret;
1204 	}
1205 
1206 	return 0;
1207 }
1208 
1209 static int guest_session__ksymbol_event(struct perf_tool *tool,
1210 					union perf_event *event,
1211 					struct perf_sample *sample __maybe_unused,
1212 					struct machine *machine __maybe_unused)
1213 {
1214 	struct guest_session *gs = container_of(tool, struct guest_session, tool);
1215 
1216 	/* Only support out-of-line i.e. no BPF support */
1217 	if (event->ksymbol.ksym_type != PERF_RECORD_KSYMBOL_TYPE_OOL)
1218 		return 0;
1219 
1220 	return guest_session__output_bytes(gs, event, event->header.size);
1221 }
1222 
1223 static int guest_session__start(struct guest_session *gs, const char *name, bool force)
1224 {
1225 	char tmp_file_name[] = "/tmp/perf-inject-guest_session-XXXXXX";
1226 	struct perf_session *session;
1227 	int ret;
1228 
1229 	/* Only these events will be injected */
1230 	gs->tool.mmap		= guest_session__repipe;
1231 	gs->tool.mmap2		= guest_session__repipe;
1232 	gs->tool.comm		= guest_session__repipe;
1233 	gs->tool.fork		= guest_session__repipe;
1234 	gs->tool.exit		= guest_session__repipe;
1235 	gs->tool.lost		= guest_session__repipe;
1236 	gs->tool.context_switch	= guest_session__repipe;
1237 	gs->tool.ksymbol	= guest_session__ksymbol_event;
1238 	gs->tool.text_poke	= guest_session__repipe;
1239 	/*
1240 	 * Processing a build ID creates a struct dso with that build ID. Later,
1241 	 * all guest dsos are iterated and the build IDs processed into the host
1242 	 * session where they will be output to the Build ID feature section
1243 	 * when the perf.data file header is written.
1244 	 */
1245 	gs->tool.build_id	= perf_event__process_build_id;
1246 	/* Process the id index to know what VCPU an ID belongs to */
1247 	gs->tool.id_index	= perf_event__process_id_index;
1248 
1249 	gs->tool.ordered_events	= true;
1250 	gs->tool.ordering_requires_timestamps = true;
1251 
1252 	gs->data.path	= name;
1253 	gs->data.force	= force;
1254 	gs->data.mode	= PERF_DATA_MODE_READ;
1255 
1256 	session = perf_session__new(&gs->data, &gs->tool);
1257 	if (IS_ERR(session))
1258 		return PTR_ERR(session);
1259 	gs->session = session;
1260 
1261 	/*
1262 	 * Initial events have zero'd ID samples. Get default ID sample size
1263 	 * used for removing them.
1264 	 */
1265 	gs->dflt_id_hdr_size = session->machines.host.id_hdr_size;
1266 	/* And default ID for adding back a host-compatible ID sample */
1267 	gs->dflt_id = evlist__first_id(session->evlist);
1268 	if (!gs->dflt_id) {
1269 		pr_err("Guest data has no sample IDs");
1270 		return -EINVAL;
1271 	}
1272 
1273 	/* Temporary file for guest events */
1274 	gs->tmp_file_name = strdup(tmp_file_name);
1275 	if (!gs->tmp_file_name)
1276 		return -ENOMEM;
1277 	gs->tmp_fd = mkstemp(gs->tmp_file_name);
1278 	if (gs->tmp_fd < 0)
1279 		return -errno;
1280 
1281 	if (zstd_init(&gs->session->zstd_data, 0) < 0)
1282 		pr_warning("Guest session decompression initialization failed.\n");
1283 
1284 	/*
1285 	 * perf does not support processing 2 sessions simultaneously, so output
1286 	 * guest events to a temporary file.
1287 	 */
1288 	ret = perf_session__process_events(gs->session);
1289 	if (ret)
1290 		return ret;
1291 
1292 	if (lseek(gs->tmp_fd, 0, SEEK_SET))
1293 		return -errno;
1294 
1295 	return 0;
1296 }
1297 
1298 /* Free hlist nodes assuming hlist_node is the first member of hlist entries */
1299 static void free_hlist(struct hlist_head *heads, size_t hlist_sz)
1300 {
1301 	struct hlist_node *pos, *n;
1302 	size_t i;
1303 
1304 	for (i = 0; i < hlist_sz; ++i) {
1305 		hlist_for_each_safe(pos, n, &heads[i]) {
1306 			hlist_del(pos);
1307 			free(pos);
1308 		}
1309 	}
1310 }
1311 
1312 static void guest_session__exit(struct guest_session *gs)
1313 {
1314 	if (gs->session) {
1315 		perf_session__delete(gs->session);
1316 		free_hlist(gs->heads, PERF_EVLIST__HLIST_SIZE);
1317 		free_hlist(gs->tids, PERF_EVLIST__HLIST_SIZE);
1318 	}
1319 	if (gs->tmp_file_name) {
1320 		if (gs->tmp_fd >= 0)
1321 			close(gs->tmp_fd);
1322 		unlink(gs->tmp_file_name);
1323 		zfree(&gs->tmp_file_name);
1324 	}
1325 	zfree(&gs->vcpu);
1326 	zfree(&gs->perf_data_file);
1327 }
1328 
1329 static void get_tsc_conv(struct perf_tsc_conversion *tc, struct perf_record_time_conv *time_conv)
1330 {
1331 	tc->time_shift		= time_conv->time_shift;
1332 	tc->time_mult		= time_conv->time_mult;
1333 	tc->time_zero		= time_conv->time_zero;
1334 	tc->time_cycles		= time_conv->time_cycles;
1335 	tc->time_mask		= time_conv->time_mask;
1336 	tc->cap_user_time_zero	= time_conv->cap_user_time_zero;
1337 	tc->cap_user_time_short	= time_conv->cap_user_time_short;
1338 }
1339 
1340 static void guest_session__get_tc(struct guest_session *gs)
1341 {
1342 	struct perf_inject *inject = container_of(gs, struct perf_inject, guest_session);
1343 
1344 	get_tsc_conv(&gs->host_tc, &inject->session->time_conv);
1345 	get_tsc_conv(&gs->guest_tc, &gs->session->time_conv);
1346 }
1347 
1348 static void guest_session__convert_time(struct guest_session *gs, u64 guest_time, u64 *host_time)
1349 {
1350 	u64 tsc;
1351 
1352 	if (!guest_time) {
1353 		*host_time = 0;
1354 		return;
1355 	}
1356 
1357 	if (gs->guest_tc.cap_user_time_zero)
1358 		tsc = perf_time_to_tsc(guest_time, &gs->guest_tc);
1359 	else
1360 		tsc = guest_time;
1361 
1362 	/*
1363 	 * This is the correct order of operations for x86 if the TSC Offset and
1364 	 * Multiplier values are used.
1365 	 */
1366 	tsc -= gs->time_offset;
1367 	tsc /= gs->time_scale;
1368 
1369 	if (gs->host_tc.cap_user_time_zero)
1370 		*host_time = tsc_to_perf_time(tsc, &gs->host_tc);
1371 	else
1372 		*host_time = tsc;
1373 }
1374 
1375 static int guest_session__fetch(struct guest_session *gs)
1376 {
1377 	void *buf;
1378 	struct perf_event_header *hdr;
1379 	size_t hdr_sz = sizeof(*hdr);
1380 	ssize_t ret;
1381 
1382 	buf = gs->ev.event_buf;
1383 	if (!buf) {
1384 		buf = malloc(PERF_SAMPLE_MAX_SIZE);
1385 		if (!buf)
1386 			return -ENOMEM;
1387 		gs->ev.event_buf = buf;
1388 	}
1389 	hdr = buf;
1390 	ret = readn(gs->tmp_fd, buf, hdr_sz);
1391 	if (ret < 0)
1392 		return ret;
1393 
1394 	if (!ret) {
1395 		/* Zero size means EOF */
1396 		hdr->size = 0;
1397 		return 0;
1398 	}
1399 
1400 	buf += hdr_sz;
1401 
1402 	ret = readn(gs->tmp_fd, buf, hdr->size - hdr_sz);
1403 	if (ret < 0)
1404 		return ret;
1405 
1406 	gs->ev.event = (union perf_event *)gs->ev.event_buf;
1407 	gs->ev.sample.time = 0;
1408 
1409 	if (hdr->type >= PERF_RECORD_USER_TYPE_START) {
1410 		pr_err("Unexpected type fetching guest event");
1411 		return 0;
1412 	}
1413 
1414 	ret = evlist__parse_sample(gs->session->evlist, gs->ev.event, &gs->ev.sample);
1415 	if (ret) {
1416 		pr_err("Parse failed fetching guest event");
1417 		return ret;
1418 	}
1419 
1420 	if (!gs->have_tc) {
1421 		guest_session__get_tc(gs);
1422 		gs->have_tc = true;
1423 	}
1424 
1425 	guest_session__convert_time(gs, gs->ev.sample.time, &gs->ev.sample.time);
1426 
1427 	return 0;
1428 }
1429 
1430 static int evlist__append_id_sample(struct evlist *evlist, union perf_event *ev,
1431 				    const struct perf_sample *sample)
1432 {
1433 	struct evsel *evsel;
1434 	void *array;
1435 	int ret;
1436 
1437 	evsel = evlist__id2evsel(evlist, sample->id);
1438 	array = ev;
1439 
1440 	if (!evsel) {
1441 		pr_err("No evsel for id %"PRIu64"\n", sample->id);
1442 		return -EINVAL;
1443 	}
1444 
1445 	array += ev->header.size;
1446 	ret = perf_event__synthesize_id_sample(array, evsel->core.attr.sample_type, sample);
1447 	if (ret < 0)
1448 		return ret;
1449 
1450 	if (ret & 7) {
1451 		pr_err("Bad id sample size %d\n", ret);
1452 		return -EINVAL;
1453 	}
1454 
1455 	ev->header.size += ret;
1456 
1457 	return 0;
1458 }
1459 
1460 static int guest_session__inject_events(struct guest_session *gs, u64 timestamp)
1461 {
1462 	struct perf_inject *inject = container_of(gs, struct perf_inject, guest_session);
1463 	int ret;
1464 
1465 	if (!gs->ready)
1466 		return 0;
1467 
1468 	while (1) {
1469 		struct perf_sample *sample;
1470 		struct guest_id *guest_id;
1471 		union perf_event *ev;
1472 		u16 id_hdr_size;
1473 		u8 cpumode;
1474 		u64 id;
1475 
1476 		if (!gs->fetched) {
1477 			ret = guest_session__fetch(gs);
1478 			if (ret)
1479 				return ret;
1480 			gs->fetched = true;
1481 		}
1482 
1483 		ev = gs->ev.event;
1484 		sample = &gs->ev.sample;
1485 
1486 		if (!ev->header.size)
1487 			return 0; /* EOF */
1488 
1489 		if (sample->time > timestamp)
1490 			return 0;
1491 
1492 		/* Change cpumode to guest */
1493 		cpumode = ev->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
1494 		if (cpumode & PERF_RECORD_MISC_USER)
1495 			cpumode = PERF_RECORD_MISC_GUEST_USER;
1496 		else
1497 			cpumode = PERF_RECORD_MISC_GUEST_KERNEL;
1498 		ev->header.misc &= ~PERF_RECORD_MISC_CPUMODE_MASK;
1499 		ev->header.misc |= cpumode;
1500 
1501 		id = sample->id;
1502 		if (!id) {
1503 			id = gs->dflt_id;
1504 			id_hdr_size = gs->dflt_id_hdr_size;
1505 		} else {
1506 			struct evsel *evsel = evlist__id2evsel(gs->session->evlist, id);
1507 
1508 			id_hdr_size = evsel__id_hdr_size(evsel);
1509 		}
1510 
1511 		if (id_hdr_size & 7) {
1512 			pr_err("Bad id_hdr_size %u\n", id_hdr_size);
1513 			return -EINVAL;
1514 		}
1515 
1516 		if (ev->header.size & 7) {
1517 			pr_err("Bad event size %u\n", ev->header.size);
1518 			return -EINVAL;
1519 		}
1520 
1521 		/* Remove guest id sample */
1522 		ev->header.size -= id_hdr_size;
1523 
1524 		if (ev->header.size & 7) {
1525 			pr_err("Bad raw event size %u\n", ev->header.size);
1526 			return -EINVAL;
1527 		}
1528 
1529 		guest_id = guest_session__lookup_id(gs, id);
1530 		if (!guest_id) {
1531 			pr_err("Guest event with unknown id %llu\n",
1532 			       (unsigned long long)id);
1533 			return -EINVAL;
1534 		}
1535 
1536 		/* Change to host ID to avoid conflicting ID values */
1537 		sample->id = guest_id->host_id;
1538 		sample->stream_id = guest_id->host_id;
1539 
1540 		if (sample->cpu != (u32)-1) {
1541 			if (sample->cpu >= gs->vcpu_cnt) {
1542 				pr_err("Guest event with unknown VCPU %u\n",
1543 				       sample->cpu);
1544 				return -EINVAL;
1545 			}
1546 			/* Change to host CPU instead of guest VCPU */
1547 			sample->cpu = gs->vcpu[sample->cpu].cpu;
1548 		}
1549 
1550 		/* New id sample with new ID and CPU */
1551 		ret = evlist__append_id_sample(inject->session->evlist, ev, sample);
1552 		if (ret)
1553 			return ret;
1554 
1555 		if (ev->header.size & 7) {
1556 			pr_err("Bad new event size %u\n", ev->header.size);
1557 			return -EINVAL;
1558 		}
1559 
1560 		gs->fetched = false;
1561 
1562 		ret = output_bytes(inject, ev, ev->header.size);
1563 		if (ret)
1564 			return ret;
1565 	}
1566 }
1567 
1568 static int guest_session__flush_events(struct guest_session *gs)
1569 {
1570 	return guest_session__inject_events(gs, -1);
1571 }
1572 
1573 static int host__repipe(struct perf_tool *tool,
1574 			union perf_event *event,
1575 			struct perf_sample *sample,
1576 			struct machine *machine)
1577 {
1578 	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
1579 	int ret;
1580 
1581 	ret = guest_session__inject_events(&inject->guest_session, sample->time);
1582 	if (ret)
1583 		return ret;
1584 
1585 	return perf_event__repipe(tool, event, sample, machine);
1586 }
1587 
1588 static int host__finished_init(struct perf_session *session, union perf_event *event)
1589 {
1590 	struct perf_inject *inject = container_of(session->tool, struct perf_inject, tool);
1591 	struct guest_session *gs = &inject->guest_session;
1592 	int ret;
1593 
1594 	/*
1595 	 * Peek through host COMM events to find QEMU threads and the VCPU they
1596 	 * are running.
1597 	 */
1598 	ret = host_peek_vm_comms(session, gs);
1599 	if (ret)
1600 		return ret;
1601 
1602 	if (!gs->vcpu_cnt) {
1603 		pr_err("No VCPU threads found for pid %u\n", gs->machine_pid);
1604 		return -EINVAL;
1605 	}
1606 
1607 	/*
1608 	 * Allocate new (unused) host sample IDs and map them to the guest IDs.
1609 	 */
1610 	gs->highest_id = evlist__find_highest_id(session->evlist);
1611 	ret = guest_session__map_ids(gs, session->evlist);
1612 	if (ret)
1613 		return ret;
1614 
1615 	ret = guest_session__add_attrs(gs);
1616 	if (ret)
1617 		return ret;
1618 
1619 	ret = synthesize_id_index(inject, gs->session->evlist->core.nr_entries);
1620 	if (ret) {
1621 		pr_err("Failed to synthesize id_index\n");
1622 		return ret;
1623 	}
1624 
1625 	ret = guest_session__add_build_ids(gs);
1626 	if (ret) {
1627 		pr_err("Failed to add guest build IDs\n");
1628 		return ret;
1629 	}
1630 
1631 	gs->ready = true;
1632 
1633 	ret = guest_session__inject_events(gs, 0);
1634 	if (ret)
1635 		return ret;
1636 
1637 	return perf_event__repipe_op2_synth(session, event);
1638 }
1639 
1640 /*
1641  * Obey finished-round ordering. The FINISHED_ROUND event is first processed
1642  * which flushes host events to file up until the last flush time. Then inject
1643  * guest events up to the same time. Finally write out the FINISHED_ROUND event
1644  * itself.
1645  */
1646 static int host__finished_round(struct perf_tool *tool,
1647 				union perf_event *event,
1648 				struct ordered_events *oe)
1649 {
1650 	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
1651 	int ret = perf_event__process_finished_round(tool, event, oe);
1652 	u64 timestamp = ordered_events__last_flush_time(oe);
1653 
1654 	if (ret)
1655 		return ret;
1656 
1657 	ret = guest_session__inject_events(&inject->guest_session, timestamp);
1658 	if (ret)
1659 		return ret;
1660 
1661 	return perf_event__repipe_oe_synth(tool, event, oe);
1662 }
1663 
1664 static int host__context_switch(struct perf_tool *tool,
1665 				union perf_event *event,
1666 				struct perf_sample *sample,
1667 				struct machine *machine)
1668 {
1669 	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);
1670 	bool out = event->header.misc & PERF_RECORD_MISC_SWITCH_OUT;
1671 	struct guest_session *gs = &inject->guest_session;
1672 	u32 pid = event->context_switch.next_prev_pid;
1673 	u32 tid = event->context_switch.next_prev_tid;
1674 	struct guest_tid *guest_tid;
1675 	u32 vcpu;
1676 
1677 	if (out || pid != gs->machine_pid)
1678 		goto out;
1679 
1680 	guest_tid = guest_session__lookup_tid(gs, tid);
1681 	if (!guest_tid)
1682 		goto out;
1683 
1684 	if (sample->cpu == (u32)-1) {
1685 		pr_err("Switch event does not have CPU\n");
1686 		return -EINVAL;
1687 	}
1688 
1689 	vcpu = guest_tid->vcpu;
1690 	if (vcpu >= gs->vcpu_cnt)
1691 		return -EINVAL;
1692 
1693 	/* Guest is switching in, record which CPU the VCPU is now running on */
1694 	gs->vcpu[vcpu].cpu = sample->cpu;
1695 out:
1696 	return host__repipe(tool, event, sample, machine);
1697 }
1698 
1699 static void sig_handler(int sig __maybe_unused)
1700 {
1701 	session_done = 1;
1702 }
1703 
1704 static int evsel__check_stype(struct evsel *evsel, u64 sample_type, const char *sample_msg)
1705 {
1706 	struct perf_event_attr *attr = &evsel->core.attr;
1707 	const char *name = evsel__name(evsel);
1708 
1709 	if (!(attr->sample_type & sample_type)) {
1710 		pr_err("Samples for %s event do not have %s attribute set.",
1711 			name, sample_msg);
1712 		return -EINVAL;
1713 	}
1714 
1715 	return 0;
1716 }
1717 
1718 static int drop_sample(struct perf_tool *tool __maybe_unused,
1719 		       union perf_event *event __maybe_unused,
1720 		       struct perf_sample *sample __maybe_unused,
1721 		       struct evsel *evsel __maybe_unused,
1722 		       struct machine *machine __maybe_unused)
1723 {
1724 	return 0;
1725 }
1726 
1727 static void strip_init(struct perf_inject *inject)
1728 {
1729 	struct evlist *evlist = inject->session->evlist;
1730 	struct evsel *evsel;
1731 
1732 	inject->tool.context_switch = perf_event__drop;
1733 
1734 	evlist__for_each_entry(evlist, evsel)
1735 		evsel->handler = drop_sample;
1736 }
1737 
1738 static int parse_vm_time_correlation(const struct option *opt, const char *str, int unset)
1739 {
1740 	struct perf_inject *inject = opt->value;
1741 	const char *args;
1742 	char *dry_run;
1743 
1744 	if (unset)
1745 		return 0;
1746 
1747 	inject->itrace_synth_opts.set = true;
1748 	inject->itrace_synth_opts.vm_time_correlation = true;
1749 	inject->in_place_update = true;
1750 
1751 	if (!str)
1752 		return 0;
1753 
1754 	dry_run = skip_spaces(str);
1755 	if (!strncmp(dry_run, "dry-run", strlen("dry-run"))) {
1756 		inject->itrace_synth_opts.vm_tm_corr_dry_run = true;
1757 		inject->in_place_update_dry_run = true;
1758 		args = dry_run + strlen("dry-run");
1759 	} else {
1760 		args = str;
1761 	}
1762 
1763 	inject->itrace_synth_opts.vm_tm_corr_args = strdup(args);
1764 
1765 	return inject->itrace_synth_opts.vm_tm_corr_args ? 0 : -ENOMEM;
1766 }
1767 
1768 static int parse_guest_data(const struct option *opt, const char *str, int unset)
1769 {
1770 	struct perf_inject *inject = opt->value;
1771 	struct guest_session *gs = &inject->guest_session;
1772 	char *tok;
1773 	char *s;
1774 
1775 	if (unset)
1776 		return 0;
1777 
1778 	if (!str)
1779 		goto bad_args;
1780 
1781 	s = strdup(str);
1782 	if (!s)
1783 		return -ENOMEM;
1784 
1785 	gs->perf_data_file = strsep(&s, ",");
1786 	if (!gs->perf_data_file)
1787 		goto bad_args;
1788 
1789 	gs->copy_kcore_dir = has_kcore_dir(gs->perf_data_file);
1790 	if (gs->copy_kcore_dir)
1791 		inject->output.is_dir = true;
1792 
1793 	tok = strsep(&s, ",");
1794 	if (!tok)
1795 		goto bad_args;
1796 	gs->machine_pid = strtoul(tok, NULL, 0);
1797 	if (!inject->guest_session.machine_pid)
1798 		goto bad_args;
1799 
1800 	gs->time_scale = 1;
1801 
1802 	tok = strsep(&s, ",");
1803 	if (!tok)
1804 		goto out;
1805 	gs->time_offset = strtoull(tok, NULL, 0);
1806 
1807 	tok = strsep(&s, ",");
1808 	if (!tok)
1809 		goto out;
1810 	gs->time_scale = strtod(tok, NULL);
1811 	if (!gs->time_scale)
1812 		goto bad_args;
1813 out:
1814 	return 0;
1815 
1816 bad_args:
1817 	pr_err("--guest-data option requires guest perf.data file name, "
1818 	       "guest machine PID, and optionally guest timestamp offset, "
1819 	       "and guest timestamp scale factor, separated by commas.\n");
1820 	return -1;
1821 }
1822 
1823 static int save_section_info_cb(struct perf_file_section *section,
1824 				struct perf_header *ph __maybe_unused,
1825 				int feat, int fd __maybe_unused, void *data)
1826 {
1827 	struct perf_inject *inject = data;
1828 
1829 	inject->secs[feat] = *section;
1830 	return 0;
1831 }
1832 
1833 static int save_section_info(struct perf_inject *inject)
1834 {
1835 	struct perf_header *header = &inject->session->header;
1836 	int fd = perf_data__fd(inject->session->data);
1837 
1838 	return perf_header__process_sections(header, fd, inject, save_section_info_cb);
1839 }
1840 
1841 static bool keep_feat(int feat)
1842 {
1843 	switch (feat) {
1844 	/* Keep original information that describes the machine or software */
1845 	case HEADER_TRACING_DATA:
1846 	case HEADER_HOSTNAME:
1847 	case HEADER_OSRELEASE:
1848 	case HEADER_VERSION:
1849 	case HEADER_ARCH:
1850 	case HEADER_NRCPUS:
1851 	case HEADER_CPUDESC:
1852 	case HEADER_CPUID:
1853 	case HEADER_TOTAL_MEM:
1854 	case HEADER_CPU_TOPOLOGY:
1855 	case HEADER_NUMA_TOPOLOGY:
1856 	case HEADER_PMU_MAPPINGS:
1857 	case HEADER_CACHE:
1858 	case HEADER_MEM_TOPOLOGY:
1859 	case HEADER_CLOCKID:
1860 	case HEADER_BPF_PROG_INFO:
1861 	case HEADER_BPF_BTF:
1862 	case HEADER_CPU_PMU_CAPS:
1863 	case HEADER_CLOCK_DATA:
1864 	case HEADER_HYBRID_TOPOLOGY:
1865 	case HEADER_PMU_CAPS:
1866 		return true;
1867 	/* Information that can be updated */
1868 	case HEADER_BUILD_ID:
1869 	case HEADER_CMDLINE:
1870 	case HEADER_EVENT_DESC:
1871 	case HEADER_BRANCH_STACK:
1872 	case HEADER_GROUP_DESC:
1873 	case HEADER_AUXTRACE:
1874 	case HEADER_STAT:
1875 	case HEADER_SAMPLE_TIME:
1876 	case HEADER_DIR_FORMAT:
1877 	case HEADER_COMPRESSED:
1878 	default:
1879 		return false;
1880 	};
1881 }
1882 
1883 static int read_file(int fd, u64 offs, void *buf, size_t sz)
1884 {
1885 	ssize_t ret = preadn(fd, buf, sz, offs);
1886 
1887 	if (ret < 0)
1888 		return -errno;
1889 	if ((size_t)ret != sz)
1890 		return -EINVAL;
1891 	return 0;
1892 }
1893 
1894 static int feat_copy(struct perf_inject *inject, int feat, struct feat_writer *fw)
1895 {
1896 	int fd = perf_data__fd(inject->session->data);
1897 	u64 offs = inject->secs[feat].offset;
1898 	size_t sz = inject->secs[feat].size;
1899 	void *buf = malloc(sz);
1900 	int ret;
1901 
1902 	if (!buf)
1903 		return -ENOMEM;
1904 
1905 	ret = read_file(fd, offs, buf, sz);
1906 	if (ret)
1907 		goto out_free;
1908 
1909 	ret = fw->write(fw, buf, sz);
1910 out_free:
1911 	free(buf);
1912 	return ret;
1913 }
1914 
1915 struct inject_fc {
1916 	struct feat_copier fc;
1917 	struct perf_inject *inject;
1918 };
1919 
1920 static int feat_copy_cb(struct feat_copier *fc, int feat, struct feat_writer *fw)
1921 {
1922 	struct inject_fc *inj_fc = container_of(fc, struct inject_fc, fc);
1923 	struct perf_inject *inject = inj_fc->inject;
1924 	int ret;
1925 
1926 	if (!inject->secs[feat].offset ||
1927 	    !keep_feat(feat))
1928 		return 0;
1929 
1930 	ret = feat_copy(inject, feat, fw);
1931 	if (ret < 0)
1932 		return ret;
1933 
1934 	return 1; /* Feature section copied */
1935 }
1936 
1937 static int copy_kcore_dir(struct perf_inject *inject)
1938 {
1939 	char *cmd;
1940 	int ret;
1941 
1942 	ret = asprintf(&cmd, "cp -r -n %s/kcore_dir* %s >/dev/null 2>&1",
1943 		       inject->input_name, inject->output.path);
1944 	if (ret < 0)
1945 		return ret;
1946 	pr_debug("%s\n", cmd);
1947 	ret = system(cmd);
1948 	free(cmd);
1949 	return ret;
1950 }
1951 
1952 static int guest_session__copy_kcore_dir(struct guest_session *gs)
1953 {
1954 	struct perf_inject *inject = container_of(gs, struct perf_inject, guest_session);
1955 	char *cmd;
1956 	int ret;
1957 
1958 	ret = asprintf(&cmd, "cp -r -n %s/kcore_dir %s/kcore_dir__%u >/dev/null 2>&1",
1959 		       gs->perf_data_file, inject->output.path, gs->machine_pid);
1960 	if (ret < 0)
1961 		return ret;
1962 	pr_debug("%s\n", cmd);
1963 	ret = system(cmd);
1964 	free(cmd);
1965 	return ret;
1966 }
1967 
1968 static int output_fd(struct perf_inject *inject)
1969 {
1970 	return inject->in_place_update ? -1 : perf_data__fd(&inject->output);
1971 }
1972 
1973 static int __cmd_inject(struct perf_inject *inject)
1974 {
1975 	int ret = -EINVAL;
1976 	struct guest_session *gs = &inject->guest_session;
1977 	struct perf_session *session = inject->session;
1978 	int fd = output_fd(inject);
1979 	u64 output_data_offset;
1980 
1981 	signal(SIGINT, sig_handler);
1982 
1983 	if (inject->build_ids || inject->sched_stat ||
1984 	    inject->itrace_synth_opts.set || inject->build_id_all) {
1985 		inject->tool.mmap	  = perf_event__repipe_mmap;
1986 		inject->tool.mmap2	  = perf_event__repipe_mmap2;
1987 		inject->tool.fork	  = perf_event__repipe_fork;
1988 #ifdef HAVE_LIBTRACEEVENT
1989 		inject->tool.tracing_data = perf_event__repipe_tracing_data;
1990 #endif
1991 	}
1992 
1993 	output_data_offset = perf_session__data_offset(session->evlist);
1994 
1995 	if (inject->build_id_all) {
1996 		inject->tool.mmap	  = perf_event__repipe_buildid_mmap;
1997 		inject->tool.mmap2	  = perf_event__repipe_buildid_mmap2;
1998 	} else if (inject->build_ids) {
1999 		inject->tool.sample = perf_event__inject_buildid;
2000 	} else if (inject->sched_stat) {
2001 		struct evsel *evsel;
2002 
2003 		evlist__for_each_entry(session->evlist, evsel) {
2004 			const char *name = evsel__name(evsel);
2005 
2006 			if (!strcmp(name, "sched:sched_switch")) {
2007 				if (evsel__check_stype(evsel, PERF_SAMPLE_TID, "TID"))
2008 					return -EINVAL;
2009 
2010 				evsel->handler = perf_inject__sched_switch;
2011 			} else if (!strcmp(name, "sched:sched_process_exit"))
2012 				evsel->handler = perf_inject__sched_process_exit;
2013 #ifdef HAVE_LIBTRACEEVENT
2014 			else if (!strncmp(name, "sched:sched_stat_", 17))
2015 				evsel->handler = perf_inject__sched_stat;
2016 #endif
2017 		}
2018 	} else if (inject->itrace_synth_opts.vm_time_correlation) {
2019 		session->itrace_synth_opts = &inject->itrace_synth_opts;
2020 		memset(&inject->tool, 0, sizeof(inject->tool));
2021 		inject->tool.id_index	    = perf_event__process_id_index;
2022 		inject->tool.auxtrace_info  = perf_event__process_auxtrace_info;
2023 		inject->tool.auxtrace	    = perf_event__process_auxtrace;
2024 		inject->tool.auxtrace_error = perf_event__process_auxtrace_error;
2025 		inject->tool.ordered_events = true;
2026 		inject->tool.ordering_requires_timestamps = true;
2027 	} else if (inject->itrace_synth_opts.set) {
2028 		session->itrace_synth_opts = &inject->itrace_synth_opts;
2029 		inject->itrace_synth_opts.inject = true;
2030 		inject->tool.comm	    = perf_event__repipe_comm;
2031 		inject->tool.namespaces	    = perf_event__repipe_namespaces;
2032 		inject->tool.exit	    = perf_event__repipe_exit;
2033 		inject->tool.id_index	    = perf_event__process_id_index;
2034 		inject->tool.auxtrace_info  = perf_event__process_auxtrace_info;
2035 		inject->tool.auxtrace	    = perf_event__process_auxtrace;
2036 		inject->tool.aux	    = perf_event__drop_aux;
2037 		inject->tool.itrace_start   = perf_event__drop_aux;
2038 		inject->tool.aux_output_hw_id = perf_event__drop_aux;
2039 		inject->tool.ordered_events = true;
2040 		inject->tool.ordering_requires_timestamps = true;
2041 		/* Allow space in the header for new attributes */
2042 		output_data_offset = roundup(8192 + session->header.data_offset, 4096);
2043 		if (inject->strip)
2044 			strip_init(inject);
2045 	} else if (gs->perf_data_file) {
2046 		char *name = gs->perf_data_file;
2047 
2048 		/*
2049 		 * Not strictly necessary, but keep these events in order wrt
2050 		 * guest events.
2051 		 */
2052 		inject->tool.mmap		= host__repipe;
2053 		inject->tool.mmap2		= host__repipe;
2054 		inject->tool.comm		= host__repipe;
2055 		inject->tool.fork		= host__repipe;
2056 		inject->tool.exit		= host__repipe;
2057 		inject->tool.lost		= host__repipe;
2058 		inject->tool.context_switch	= host__repipe;
2059 		inject->tool.ksymbol		= host__repipe;
2060 		inject->tool.text_poke		= host__repipe;
2061 		/*
2062 		 * Once the host session has initialized, set up sample ID
2063 		 * mapping and feed in guest attrs, build IDs and initial
2064 		 * events.
2065 		 */
2066 		inject->tool.finished_init	= host__finished_init;
2067 		/* Obey finished round ordering */
2068 		inject->tool.finished_round	= host__finished_round,
2069 		/* Keep track of which CPU a VCPU is runnng on */
2070 		inject->tool.context_switch	= host__context_switch;
2071 		/*
2072 		 * Must order events to be able to obey finished round
2073 		 * ordering.
2074 		 */
2075 		inject->tool.ordered_events	= true;
2076 		inject->tool.ordering_requires_timestamps = true;
2077 		/* Set up a separate session to process guest perf.data file */
2078 		ret = guest_session__start(gs, name, session->data->force);
2079 		if (ret) {
2080 			pr_err("Failed to process %s, error %d\n", name, ret);
2081 			return ret;
2082 		}
2083 		/* Allow space in the header for guest attributes */
2084 		output_data_offset += gs->session->header.data_offset;
2085 		output_data_offset = roundup(output_data_offset, 4096);
2086 	}
2087 
2088 	if (!inject->itrace_synth_opts.set)
2089 		auxtrace_index__free(&session->auxtrace_index);
2090 
2091 	if (!inject->is_pipe && !inject->in_place_update)
2092 		lseek(fd, output_data_offset, SEEK_SET);
2093 
2094 	ret = perf_session__process_events(session);
2095 	if (ret)
2096 		return ret;
2097 
2098 	if (gs->session) {
2099 		/*
2100 		 * Remaining guest events have later timestamps. Flush them
2101 		 * out to file.
2102 		 */
2103 		ret = guest_session__flush_events(gs);
2104 		if (ret) {
2105 			pr_err("Failed to flush guest events\n");
2106 			return ret;
2107 		}
2108 	}
2109 
2110 	if (!inject->is_pipe && !inject->in_place_update) {
2111 		struct inject_fc inj_fc = {
2112 			.fc.copy = feat_copy_cb,
2113 			.inject = inject,
2114 		};
2115 
2116 		if (inject->build_ids)
2117 			perf_header__set_feat(&session->header,
2118 					      HEADER_BUILD_ID);
2119 		/*
2120 		 * Keep all buildids when there is unprocessed AUX data because
2121 		 * it is not known which ones the AUX trace hits.
2122 		 */
2123 		if (perf_header__has_feat(&session->header, HEADER_BUILD_ID) &&
2124 		    inject->have_auxtrace && !inject->itrace_synth_opts.set)
2125 			dsos__hit_all(session);
2126 		/*
2127 		 * The AUX areas have been removed and replaced with
2128 		 * synthesized hardware events, so clear the feature flag.
2129 		 */
2130 		if (inject->itrace_synth_opts.set) {
2131 			perf_header__clear_feat(&session->header,
2132 						HEADER_AUXTRACE);
2133 			if (inject->itrace_synth_opts.last_branch ||
2134 			    inject->itrace_synth_opts.add_last_branch)
2135 				perf_header__set_feat(&session->header,
2136 						      HEADER_BRANCH_STACK);
2137 		}
2138 		session->header.data_offset = output_data_offset;
2139 		session->header.data_size = inject->bytes_written;
2140 		perf_session__inject_header(session, session->evlist, fd, &inj_fc.fc);
2141 
2142 		if (inject->copy_kcore_dir) {
2143 			ret = copy_kcore_dir(inject);
2144 			if (ret) {
2145 				pr_err("Failed to copy kcore\n");
2146 				return ret;
2147 			}
2148 		}
2149 		if (gs->copy_kcore_dir) {
2150 			ret = guest_session__copy_kcore_dir(gs);
2151 			if (ret) {
2152 				pr_err("Failed to copy guest kcore\n");
2153 				return ret;
2154 			}
2155 		}
2156 	}
2157 
2158 	return ret;
2159 }
2160 
2161 int cmd_inject(int argc, const char **argv)
2162 {
2163 	struct perf_inject inject = {
2164 		.tool = {
2165 			.sample		= perf_event__repipe_sample,
2166 			.read		= perf_event__repipe_sample,
2167 			.mmap		= perf_event__repipe,
2168 			.mmap2		= perf_event__repipe,
2169 			.comm		= perf_event__repipe,
2170 			.namespaces	= perf_event__repipe,
2171 			.cgroup		= perf_event__repipe,
2172 			.fork		= perf_event__repipe,
2173 			.exit		= perf_event__repipe,
2174 			.lost		= perf_event__repipe,
2175 			.lost_samples	= perf_event__repipe,
2176 			.aux		= perf_event__repipe,
2177 			.itrace_start	= perf_event__repipe,
2178 			.aux_output_hw_id = perf_event__repipe,
2179 			.context_switch	= perf_event__repipe,
2180 			.throttle	= perf_event__repipe,
2181 			.unthrottle	= perf_event__repipe,
2182 			.ksymbol	= perf_event__repipe,
2183 			.bpf		= perf_event__repipe,
2184 			.text_poke	= perf_event__repipe,
2185 			.attr		= perf_event__repipe_attr,
2186 			.event_update	= perf_event__repipe_event_update,
2187 			.tracing_data	= perf_event__repipe_op2_synth,
2188 			.finished_round	= perf_event__repipe_oe_synth,
2189 			.build_id	= perf_event__repipe_op2_synth,
2190 			.id_index	= perf_event__repipe_op2_synth,
2191 			.auxtrace_info	= perf_event__repipe_op2_synth,
2192 			.auxtrace_error	= perf_event__repipe_op2_synth,
2193 			.time_conv	= perf_event__repipe_op2_synth,
2194 			.thread_map	= perf_event__repipe_op2_synth,
2195 			.cpu_map	= perf_event__repipe_op2_synth,
2196 			.stat_config	= perf_event__repipe_op2_synth,
2197 			.stat		= perf_event__repipe_op2_synth,
2198 			.stat_round	= perf_event__repipe_op2_synth,
2199 			.feature	= perf_event__repipe_op2_synth,
2200 			.finished_init	= perf_event__repipe_op2_synth,
2201 			.compressed	= perf_event__repipe_op4_synth,
2202 			.auxtrace	= perf_event__repipe_auxtrace,
2203 		},
2204 		.input_name  = "-",
2205 		.samples = LIST_HEAD_INIT(inject.samples),
2206 		.output = {
2207 			.path = "-",
2208 			.mode = PERF_DATA_MODE_WRITE,
2209 			.use_stdio = true,
2210 		},
2211 	};
2212 	struct perf_data data = {
2213 		.mode = PERF_DATA_MODE_READ,
2214 		.use_stdio = true,
2215 	};
2216 	int ret;
2217 	bool repipe = true;
2218 	const char *known_build_ids = NULL;
2219 
2220 	struct option options[] = {
2221 		OPT_BOOLEAN('b', "build-ids", &inject.build_ids,
2222 			    "Inject build-ids into the output stream"),
2223 		OPT_BOOLEAN(0, "buildid-all", &inject.build_id_all,
2224 			    "Inject build-ids of all DSOs into the output stream"),
2225 		OPT_STRING(0, "known-build-ids", &known_build_ids,
2226 			   "buildid path [,buildid path...]",
2227 			   "build-ids to use for given paths"),
2228 		OPT_STRING('i', "input", &inject.input_name, "file",
2229 			   "input file name"),
2230 		OPT_STRING('o', "output", &inject.output.path, "file",
2231 			   "output file name"),
2232 		OPT_BOOLEAN('s', "sched-stat", &inject.sched_stat,
2233 			    "Merge sched-stat and sched-switch for getting events "
2234 			    "where and how long tasks slept"),
2235 #ifdef HAVE_JITDUMP
2236 		OPT_BOOLEAN('j', "jit", &inject.jit_mode, "merge jitdump files into perf.data file"),
2237 #endif
2238 		OPT_INCR('v', "verbose", &verbose,
2239 			 "be more verbose (show build ids, etc)"),
2240 		OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
2241 			   "file", "vmlinux pathname"),
2242 		OPT_BOOLEAN(0, "ignore-vmlinux", &symbol_conf.ignore_vmlinux,
2243 			    "don't load vmlinux even if found"),
2244 		OPT_STRING(0, "kallsyms", &symbol_conf.kallsyms_name, "file",
2245 			   "kallsyms pathname"),
2246 		OPT_BOOLEAN('f', "force", &data.force, "don't complain, do it"),
2247 		OPT_CALLBACK_OPTARG(0, "itrace", &inject.itrace_synth_opts,
2248 				    NULL, "opts", "Instruction Tracing options\n"
2249 				    ITRACE_HELP,
2250 				    itrace_parse_synth_opts),
2251 		OPT_BOOLEAN(0, "strip", &inject.strip,
2252 			    "strip non-synthesized events (use with --itrace)"),
2253 		OPT_CALLBACK_OPTARG(0, "vm-time-correlation", &inject, NULL, "opts",
2254 				    "correlate time between VM guests and the host",
2255 				    parse_vm_time_correlation),
2256 		OPT_CALLBACK_OPTARG(0, "guest-data", &inject, NULL, "opts",
2257 				    "inject events from a guest perf.data file",
2258 				    parse_guest_data),
2259 		OPT_STRING(0, "guestmount", &symbol_conf.guestmount, "directory",
2260 			   "guest mount directory under which every guest os"
2261 			   " instance has a subdir"),
2262 		OPT_END()
2263 	};
2264 	const char * const inject_usage[] = {
2265 		"perf inject [<options>]",
2266 		NULL
2267 	};
2268 
2269 	if (!inject.itrace_synth_opts.set) {
2270 		/* Disable eager loading of kernel symbols that adds overhead to perf inject. */
2271 		symbol_conf.lazy_load_kernel_maps = true;
2272 	}
2273 
2274 #ifndef HAVE_JITDUMP
2275 	set_option_nobuild(options, 'j', "jit", "NO_LIBELF=1", true);
2276 #endif
2277 	argc = parse_options(argc, argv, options, inject_usage, 0);
2278 
2279 	/*
2280 	 * Any (unrecognized) arguments left?
2281 	 */
2282 	if (argc)
2283 		usage_with_options(inject_usage, options);
2284 
2285 	if (inject.strip && !inject.itrace_synth_opts.set) {
2286 		pr_err("--strip option requires --itrace option\n");
2287 		return -1;
2288 	}
2289 
2290 	if (symbol__validate_sym_arguments())
2291 		return -1;
2292 
2293 	if (inject.in_place_update) {
2294 		if (!strcmp(inject.input_name, "-")) {
2295 			pr_err("Input file name required for in-place updating\n");
2296 			return -1;
2297 		}
2298 		if (strcmp(inject.output.path, "-")) {
2299 			pr_err("Output file name must not be specified for in-place updating\n");
2300 			return -1;
2301 		}
2302 		if (!data.force && !inject.in_place_update_dry_run) {
2303 			pr_err("The input file would be updated in place, "
2304 				"the --force option is required.\n");
2305 			return -1;
2306 		}
2307 		if (!inject.in_place_update_dry_run)
2308 			data.in_place_update = true;
2309 	} else {
2310 		if (strcmp(inject.output.path, "-") && !inject.strip &&
2311 		    has_kcore_dir(inject.input_name)) {
2312 			inject.output.is_dir = true;
2313 			inject.copy_kcore_dir = true;
2314 		}
2315 		if (perf_data__open(&inject.output)) {
2316 			perror("failed to create output file");
2317 			return -1;
2318 		}
2319 	}
2320 
2321 	data.path = inject.input_name;
2322 	if (!strcmp(inject.input_name, "-") || inject.output.is_pipe) {
2323 		inject.is_pipe = true;
2324 		/*
2325 		 * Do not repipe header when input is a regular file
2326 		 * since either it can rewrite the header at the end
2327 		 * or write a new pipe header.
2328 		 */
2329 		if (strcmp(inject.input_name, "-"))
2330 			repipe = false;
2331 	}
2332 
2333 	inject.session = __perf_session__new(&data, repipe,
2334 					     output_fd(&inject),
2335 					     &inject.tool);
2336 	if (IS_ERR(inject.session)) {
2337 		ret = PTR_ERR(inject.session);
2338 		goto out_close_output;
2339 	}
2340 
2341 	if (zstd_init(&(inject.session->zstd_data), 0) < 0)
2342 		pr_warning("Decompression initialization failed.\n");
2343 
2344 	/* Save original section info before feature bits change */
2345 	ret = save_section_info(&inject);
2346 	if (ret)
2347 		goto out_delete;
2348 
2349 	if (!data.is_pipe && inject.output.is_pipe) {
2350 		ret = perf_header__write_pipe(perf_data__fd(&inject.output));
2351 		if (ret < 0) {
2352 			pr_err("Couldn't write a new pipe header.\n");
2353 			goto out_delete;
2354 		}
2355 
2356 		ret = perf_event__synthesize_for_pipe(&inject.tool,
2357 						      inject.session,
2358 						      &inject.output,
2359 						      perf_event__repipe);
2360 		if (ret < 0)
2361 			goto out_delete;
2362 	}
2363 
2364 	if (inject.build_ids && !inject.build_id_all) {
2365 		/*
2366 		 * to make sure the mmap records are ordered correctly
2367 		 * and so that the correct especially due to jitted code
2368 		 * mmaps. We cannot generate the buildid hit list and
2369 		 * inject the jit mmaps at the same time for now.
2370 		 */
2371 		inject.tool.ordered_events = true;
2372 		inject.tool.ordering_requires_timestamps = true;
2373 		if (known_build_ids != NULL) {
2374 			inject.known_build_ids =
2375 				perf_inject__parse_known_build_ids(known_build_ids);
2376 
2377 			if (inject.known_build_ids == NULL) {
2378 				pr_err("Couldn't parse known build ids.\n");
2379 				goto out_delete;
2380 			}
2381 		}
2382 	}
2383 
2384 	if (inject.sched_stat) {
2385 		inject.tool.ordered_events = true;
2386 	}
2387 
2388 #ifdef HAVE_JITDUMP
2389 	if (inject.jit_mode) {
2390 		inject.tool.mmap2	   = perf_event__jit_repipe_mmap2;
2391 		inject.tool.mmap	   = perf_event__jit_repipe_mmap;
2392 		inject.tool.ordered_events = true;
2393 		inject.tool.ordering_requires_timestamps = true;
2394 		/*
2395 		 * JIT MMAP injection injects all MMAP events in one go, so it
2396 		 * does not obey finished_round semantics.
2397 		 */
2398 		inject.tool.finished_round = perf_event__drop_oe;
2399 	}
2400 #endif
2401 	ret = symbol__init(&inject.session->header.env);
2402 	if (ret < 0)
2403 		goto out_delete;
2404 
2405 	ret = __cmd_inject(&inject);
2406 
2407 	guest_session__exit(&inject.guest_session);
2408 
2409 out_delete:
2410 	strlist__delete(inject.known_build_ids);
2411 	zstd_fini(&(inject.session->zstd_data));
2412 	perf_session__delete(inject.session);
2413 out_close_output:
2414 	if (!inject.in_place_update)
2415 		perf_data__close(&inject.output);
2416 	free(inject.itrace_synth_opts.vm_tm_corr_args);
2417 	free(inject.event_copy);
2418 	free(inject.guest_session.ev.event_buf);
2419 	return ret;
2420 }
2421