// SPDX-License-Identifier: GPL-2.0

  #include "builtin.h"
  #include "perf.h"

  #include "util/build-id.h"

  #include "util/evsel.h"

  #include "util/evlist.h"

  #include "util/mmap.h"

  #include "util/term.h"

  #include "util/symbol.h"
  #include "util/thread.h"
  #include "util/header.h"
  #include "util/session.h"

  #include "util/intlist.h"

  #include <subcmd/pager.h>

  #include <subcmd/parse-options.h>

  #include "util/trace-event.h"

  #include "util/debug.h"

  #include "util/tool.h"
  #include "util/stat.h"

  #include "util/synthetic-events.h"

  #include "util/top.h"

  #include "util/data.h"

  #include "util/ordered-events.h"

  #include "util/kvm-stat.h"

  #include "ui/ui.h"

  
  #include <sys/prctl.h>

  #ifdef HAVE_TIMERFD_SUPPORT

  #include <sys/timerfd.h>

  #endif

  #include <sys/time.h>

  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>

  #include <linux/err.h>

  #include <linux/kernel.h>

  #include <linux/string.h>

  #include <linux/time64.h>

  #include <linux/zalloc.h>

  #include <errno.h>

  #include <inttypes.h>

  #include <poll.h>

  #include <termios.h>

  #include <semaphore.h>

  #include <signal.h>

  #include <math.h>

  #include <perf/mmap.h>

  static const char *get_filename_for_perf_kvm(void)
  {
  	const char *filename;
  
  	if (perf_host && !perf_guest)
  		filename = strdup("perf.data.host");
  	else if (!perf_host && perf_guest)
  		filename = strdup("perf.data.guest");
  	else
  		filename = strdup("perf.data.kvm");
  
  	return filename;
  }

  #ifdef HAVE_KVM_STAT_SUPPORT

  void exit_event_get_key(struct evsel *evsel,

  			struct perf_sample *sample,
  			struct event_key *key)

  {
  	key->info = 0;

  	key->key  = evsel__intval(evsel, sample, kvm_exit_reason);

  }

  bool kvm_exit_event(struct evsel *evsel)

  {

  	return !strcmp(evsel->name, kvm_exit_trace);

  }

  bool exit_event_begin(struct evsel *evsel,

  		      struct perf_sample *sample, struct event_key *key)

  {

  	if (kvm_exit_event(evsel)) {
  		exit_event_get_key(evsel, sample, key);

  		return true;
  	}
  
  	return false;
  }

  bool kvm_entry_event(struct evsel *evsel)

  {

  	return !strcmp(evsel->name, kvm_entry_trace);

  }

  bool exit_event_end(struct evsel *evsel,

  		    struct perf_sample *sample __maybe_unused,
  		    struct event_key *key __maybe_unused)

  {

  	return kvm_entry_event(evsel);

  }

  static const char *get_exit_reason(struct perf_kvm_stat *kvm,
  				   struct exit_reasons_table *tbl,
  				   u64 exit_code)

  {

  	while (tbl->reason != NULL) {

  		if (tbl->exit_code == exit_code)
  			return tbl->reason;
  		tbl++;

  	}
  
  	pr_err("unknown kvm exit code:%lld on %s
  ",

  		(unsigned long long)exit_code, kvm->exit_reasons_isa);

  	return "UNKNOWN";
  }

  void exit_event_decode_key(struct perf_kvm_stat *kvm,
  			   struct event_key *key,
  			   char *decode)

  {

  	const char *exit_reason = get_exit_reason(kvm, key->exit_reasons,

  						  key->key);

  	scnprintf(decode, decode_str_len, "%s", exit_reason);

  }

  static bool register_kvm_events_ops(struct perf_kvm_stat *kvm)

  {

  	struct kvm_reg_events_ops *events_ops = kvm_reg_events_ops;

  	for (events_ops = kvm_reg_events_ops; events_ops->name; events_ops++) {
  		if (!strcmp(events_ops->name, kvm->report_event)) {
  			kvm->events_ops = events_ops->ops;
  			return true;
  		}

  	}
  
  	return false;
  }

  struct vcpu_event_record {
  	int vcpu_id;
  	u64 start_time;
  	struct kvm_event *last_event;
  };

  static void init_kvm_event_record(struct perf_kvm_stat *kvm)

  {

  	unsigned int i;

  	for (i = 0; i < EVENTS_CACHE_SIZE; i++)

  		INIT_LIST_HEAD(&kvm->kvm_events_cache[i]);

  }

  #ifdef HAVE_TIMERFD_SUPPORT

  static void clear_events_cache_stats(struct list_head *kvm_events_cache)
  {
  	struct list_head *head;
  	struct kvm_event *event;
  	unsigned int i;

  	int j;

  
  	for (i = 0; i < EVENTS_CACHE_SIZE; i++) {
  		head = &kvm_events_cache[i];
  		list_for_each_entry(event, head, hash_entry) {
  			/* reset stats for event */

  			event->total.time = 0;
  			init_stats(&event->total.stats);
  
  			for (j = 0; j < event->max_vcpu; ++j) {
  				event->vcpu[j].time = 0;
  				init_stats(&event->vcpu[j].stats);
  			}

  		}
  	}
  }

  #endif

  static int kvm_events_hash_fn(u64 key)
  {
  	return key & (EVENTS_CACHE_SIZE - 1);
  }
  
  static bool kvm_event_expand(struct kvm_event *event, int vcpu_id)
  {
  	int old_max_vcpu = event->max_vcpu;

  	void *prev;

  
  	if (vcpu_id < event->max_vcpu)
  		return true;
  
  	while (event->max_vcpu <= vcpu_id)
  		event->max_vcpu += DEFAULT_VCPU_NUM;

  	prev = event->vcpu;

  	event->vcpu = realloc(event->vcpu,
  			      event->max_vcpu * sizeof(*event->vcpu));
  	if (!event->vcpu) {

  		free(prev);

  		pr_err("Not enough memory
  ");
  		return false;
  	}
  
  	memset(event->vcpu + old_max_vcpu, 0,
  	       (event->max_vcpu - old_max_vcpu) * sizeof(*event->vcpu));
  	return true;
  }
  
  static struct kvm_event *kvm_alloc_init_event(struct event_key *key)
  {
  	struct kvm_event *event;
  
  	event = zalloc(sizeof(*event));
  	if (!event) {
  		pr_err("Not enough memory
  ");
  		return NULL;
  	}
  
  	event->key = *key;

  	init_stats(&event->total.stats);

  	return event;
  }

  static struct kvm_event *find_create_kvm_event(struct perf_kvm_stat *kvm,

  					       struct event_key *key)

  {
  	struct kvm_event *event;
  	struct list_head *head;
  
  	BUG_ON(key->key == INVALID_KEY);

  	head = &kvm->kvm_events_cache[kvm_events_hash_fn(key->key)];

  	list_for_each_entry(event, head, hash_entry) {

  		if (event->key.key == key->key && event->key.info == key->info)
  			return event;

  	}

  
  	event = kvm_alloc_init_event(key);
  	if (!event)
  		return NULL;
  
  	list_add(&event->hash_entry, head);
  	return event;
  }

  static bool handle_begin_event(struct perf_kvm_stat *kvm,

  			       struct vcpu_event_record *vcpu_record,

  			       struct event_key *key, u64 timestamp)
  {
  	struct kvm_event *event = NULL;
  
  	if (key->key != INVALID_KEY)

  		event = find_create_kvm_event(kvm, key);

  
  	vcpu_record->last_event = event;
  	vcpu_record->start_time = timestamp;
  	return true;
  }
  
  static void
  kvm_update_event_stats(struct kvm_event_stats *kvm_stats, u64 time_diff)
  {
  	kvm_stats->time += time_diff;
  	update_stats(&kvm_stats->stats, time_diff);
  }
  
  static double kvm_event_rel_stddev(int vcpu_id, struct kvm_event *event)
  {
  	struct kvm_event_stats *kvm_stats = &event->total;
  
  	if (vcpu_id != -1)
  		kvm_stats = &event->vcpu[vcpu_id];
  
  	return rel_stddev_stats(stddev_stats(&kvm_stats->stats),
  				avg_stats(&kvm_stats->stats));
  }
  
  static bool update_kvm_event(struct kvm_event *event, int vcpu_id,
  			     u64 time_diff)
  {

  	if (vcpu_id == -1) {
  		kvm_update_event_stats(&event->total, time_diff);
  		return true;
  	}

  
  	if (!kvm_event_expand(event, vcpu_id))
  		return false;
  
  	kvm_update_event_stats(&event->vcpu[vcpu_id], time_diff);
  	return true;
  }

  static bool is_child_event(struct perf_kvm_stat *kvm,

  			   struct evsel *evsel,

  			   struct perf_sample *sample,
  			   struct event_key *key)
  {
  	struct child_event_ops *child_ops;
  
  	child_ops = kvm->events_ops->child_ops;
  
  	if (!child_ops)
  		return false;
  
  	for (; child_ops->name; child_ops++) {
  		if (!strcmp(evsel->name, child_ops->name)) {
  			child_ops->get_key(evsel, sample, key);
  			return true;
  		}
  	}
  
  	return false;
  }
  
  static bool handle_child_event(struct perf_kvm_stat *kvm,
  			       struct vcpu_event_record *vcpu_record,
  			       struct event_key *key,
  			       struct perf_sample *sample __maybe_unused)
  {
  	struct kvm_event *event = NULL;
  
  	if (key->key != INVALID_KEY)
  		event = find_create_kvm_event(kvm, key);
  
  	vcpu_record->last_event = event;
  
  	return true;
  }

  static bool skip_event(const char *event)
  {
  	const char * const *skip_events;
  
  	for (skip_events = kvm_skip_events; *skip_events; skip_events++)
  		if (!strcmp(event, *skip_events))
  			return true;
  
  	return false;
  }

  static bool handle_end_event(struct perf_kvm_stat *kvm,

  			     struct vcpu_event_record *vcpu_record,
  			     struct event_key *key,

  			     struct perf_sample *sample)

  {
  	struct kvm_event *event;
  	u64 time_begin, time_diff;

  	int vcpu;
  
  	if (kvm->trace_vcpu == -1)
  		vcpu = -1;
  	else
  		vcpu = vcpu_record->vcpu_id;

  
  	event = vcpu_record->last_event;
  	time_begin = vcpu_record->start_time;
  
  	/* The begin event is not caught. */
  	if (!time_begin)
  		return true;
  
  	/*
  	 * In some case, the 'begin event' only records the start timestamp,
  	 * the actual event is recognized in the 'end event' (e.g. mmio-event).
  	 */
  
  	/* Both begin and end events did not get the key. */
  	if (!event && key->key == INVALID_KEY)
  		return true;
  
  	if (!event)

  		event = find_create_kvm_event(kvm, key);

  
  	if (!event)
  		return false;
  
  	vcpu_record->last_event = NULL;
  	vcpu_record->start_time = 0;

  	/* seems to happen once in a while during live mode */

  	if (sample->time < time_begin) {

  		pr_debug("End time before begin time; skipping event.
  ");
  		return true;
  	}

  	time_diff = sample->time - time_begin;
  
  	if (kvm->duration && time_diff > kvm->duration) {

  		char decode[decode_str_len];

  
  		kvm->events_ops->decode_key(kvm, &event->key, decode);

  		if (!skip_event(decode)) {

  			pr_info("%" PRIu64 " VM %d, vcpu %d: %s event took %" PRIu64 "usec
  ",
  				 sample->time, sample->pid, vcpu_record->vcpu_id,

  				 decode, time_diff / NSEC_PER_USEC);

  		}
  	}

  	return update_kvm_event(event, vcpu, time_diff);

  }

  static
  struct vcpu_event_record *per_vcpu_record(struct thread *thread,

  					  struct evsel *evsel,

  					  struct perf_sample *sample)

  {
  	/* Only kvm_entry records vcpu id. */

  	if (!thread__priv(thread) && kvm_entry_event(evsel)) {

  		struct vcpu_event_record *vcpu_record;

  		vcpu_record = zalloc(sizeof(*vcpu_record));

  		if (!vcpu_record) {

  			pr_err("%s: Not enough memory
  ", __func__);

  			return NULL;
  		}

  		vcpu_record->vcpu_id = evsel__intval(evsel, sample, vcpu_id_str);

  		thread__set_priv(thread, vcpu_record);

  	}

  	return thread__priv(thread);

  }

  static bool handle_kvm_event(struct perf_kvm_stat *kvm,

  			     struct thread *thread,

  			     struct evsel *evsel,

  			     struct perf_sample *sample)

  {
  	struct vcpu_event_record *vcpu_record;

  	struct event_key key = { .key = INVALID_KEY,
  				 .exit_reasons = kvm->exit_reasons };

  	vcpu_record = per_vcpu_record(thread, evsel, sample);

  	if (!vcpu_record)
  		return true;

  	/* only process events for vcpus user cares about */
  	if ((kvm->trace_vcpu != -1) &&
  	    (kvm->trace_vcpu != vcpu_record->vcpu_id))
  		return true;

  	if (kvm->events_ops->is_begin_event(evsel, sample, &key))
  		return handle_begin_event(kvm, vcpu_record, &key, sample->time);

  	if (is_child_event(kvm, evsel, sample, &key))
  		return handle_child_event(kvm, vcpu_record, &key, sample);

  	if (kvm->events_ops->is_end_event(evsel, sample, &key))

  		return handle_end_event(kvm, vcpu_record, &key, sample);

  
  	return true;
  }

  #define GET_EVENT_KEY(func, field)					\
  static u64 get_event_ ##func(struct kvm_event *event, int vcpu)		\
  {									\
  	if (vcpu == -1)							\
  		return event->total.field;				\
  									\
  	if (vcpu >= event->max_vcpu)					\
  		return 0;						\
  									\
  	return event->vcpu[vcpu].field;					\
  }
  
  #define COMPARE_EVENT_KEY(func, field)					\
  GET_EVENT_KEY(func, field)						\
  static int compare_kvm_event_ ## func(struct kvm_event *one,		\
  					struct kvm_event *two, int vcpu)\
  {									\
  	return get_event_ ##func(one, vcpu) >				\
  				get_event_ ##func(two, vcpu);		\
  }
  
  GET_EVENT_KEY(time, time);
  COMPARE_EVENT_KEY(count, stats.n);
  COMPARE_EVENT_KEY(mean, stats.mean);

  GET_EVENT_KEY(max, stats.max);
  GET_EVENT_KEY(min, stats.min);

  
  #define DEF_SORT_NAME_KEY(name, compare_key)				\
  	{ #name, compare_kvm_event_ ## compare_key }
  
  static struct kvm_event_key keys[] = {
  	DEF_SORT_NAME_KEY(sample, count),
  	DEF_SORT_NAME_KEY(time, mean),
  	{ NULL, NULL }
  };

  static bool select_key(struct perf_kvm_stat *kvm)

  {
  	int i;
  
  	for (i = 0; keys[i].name; i++) {

  		if (!strcmp(keys[i].name, kvm->sort_key)) {
  			kvm->compare = keys[i].key;

  			return true;
  		}
  	}

  	pr_err("Unknown compare key:%s
  ", kvm->sort_key);

  	return false;
  }

  static void insert_to_result(struct rb_root *result, struct kvm_event *event,
  			     key_cmp_fun bigger, int vcpu)

  {

  	struct rb_node **rb = &result->rb_node;

  	struct rb_node *parent = NULL;
  	struct kvm_event *p;
  
  	while (*rb) {
  		p = container_of(*rb, struct kvm_event, rb);
  		parent = *rb;
  
  		if (bigger(event, p, vcpu))
  			rb = &(*rb)->rb_left;
  		else
  			rb = &(*rb)->rb_right;
  	}
  
  	rb_link_node(&event->rb, parent, rb);

  	rb_insert_color(&event->rb, result);

  }

  static void
  update_total_count(struct perf_kvm_stat *kvm, struct kvm_event *event)

  {

  	int vcpu = kvm->trace_vcpu;
  
  	kvm->total_count += get_event_count(event, vcpu);
  	kvm->total_time += get_event_time(event, vcpu);

  }
  
  static bool event_is_valid(struct kvm_event *event, int vcpu)
  {
  	return !!get_event_count(event, vcpu);
  }

  static void sort_result(struct perf_kvm_stat *kvm)

  {
  	unsigned int i;

  	int vcpu = kvm->trace_vcpu;

  	struct kvm_event *event;

  	for (i = 0; i < EVENTS_CACHE_SIZE; i++) {
  		list_for_each_entry(event, &kvm->kvm_events_cache[i], hash_entry) {

  			if (event_is_valid(event, vcpu)) {

  				update_total_count(kvm, event);
  				insert_to_result(&kvm->result, event,
  						 kvm->compare, vcpu);

  			}

  		}
  	}

  }
  
  /* returns left most element of result, and erase it */

  static struct kvm_event *pop_from_result(struct rb_root *result)

  {

  	struct rb_node *node = rb_first(result);

  
  	if (!node)
  		return NULL;

  	rb_erase(node, result);

  	return container_of(node, struct kvm_event, rb);
  }

  static void print_vcpu_info(struct perf_kvm_stat *kvm)

  {

  	int vcpu = kvm->trace_vcpu;

  	pr_info("Analyze events for ");

  	if (kvm->opts.target.system_wide)
  		pr_info("all VMs, ");
  	else if (kvm->opts.target.pid)
  		pr_info("pid(s) %s, ", kvm->opts.target.pid);
  	else
  		pr_info("dazed and confused on what is monitored, ");

  	if (vcpu == -1)
  		pr_info("all VCPUs:
  
  ");
  	else
  		pr_info("VCPU %d:
  
  ", vcpu);
  }

  static void show_timeofday(void)
  {
  	char date[64];
  	struct timeval tv;
  	struct tm ltime;
  
  	gettimeofday(&tv, NULL);
  	if (localtime_r(&tv.tv_sec, &ltime)) {
  		strftime(date, sizeof(date), "%H:%M:%S", &ltime);
  		pr_info("%s.%06ld", date, tv.tv_usec);
  	} else
  		pr_info("00:00:00.000000");
  
  	return;
  }

  static void print_result(struct perf_kvm_stat *kvm)

  {

  	char decode[decode_str_len];

  	struct kvm_event *event;

  	int vcpu = kvm->trace_vcpu;

  	if (kvm->live) {
  		puts(CONSOLE_CLEAR);
  		show_timeofday();
  	}

  	pr_info("
  
  ");

  	print_vcpu_info(kvm);

  	pr_info("%*s ", decode_str_len, kvm->events_ops->name);

  	pr_info("%10s ", "Samples");
  	pr_info("%9s ", "Samples%");
  
  	pr_info("%9s ", "Time%");

  	pr_info("%11s ", "Min Time");
  	pr_info("%11s ", "Max Time");

  	pr_info("%16s ", "Avg time");
  	pr_info("
  
  ");

  	while ((event = pop_from_result(&kvm->result))) {

  		u64 ecount, etime, max, min;

  
  		ecount = get_event_count(event, vcpu);
  		etime = get_event_time(event, vcpu);

  		max = get_event_max(event, vcpu);
  		min = get_event_min(event, vcpu);

  		kvm->events_ops->decode_key(kvm, &event->key, decode);

  		pr_info("%*s ", decode_str_len, decode);

  		pr_info("%10llu ", (unsigned long long)ecount);

  		pr_info("%8.2f%% ", (double)ecount / kvm->total_count * 100);
  		pr_info("%8.2f%% ", (double)etime / kvm->total_time * 100);

  		pr_info("%9.2fus ", (double)min / NSEC_PER_USEC);
  		pr_info("%9.2fus ", (double)max / NSEC_PER_USEC);
  		pr_info("%9.2fus ( +-%7.2f%% )", (double)etime / ecount / NSEC_PER_USEC,

  			kvm_event_rel_stddev(vcpu, event));
  		pr_info("
  ");
  	}

  	pr_info("
  Total Samples:%" PRIu64 ", Total events handled time:%.2fus.
  
  ",

  		kvm->total_count, kvm->total_time / (double)NSEC_PER_USEC);

  
  	if (kvm->lost_events)
  		pr_info("
  Lost events: %" PRIu64 "
  
  ", kvm->lost_events);
  }

  #ifdef HAVE_TIMERFD_SUPPORT

  static int process_lost_event(struct perf_tool *tool,
  			      union perf_event *event __maybe_unused,
  			      struct perf_sample *sample __maybe_unused,
  			      struct machine *machine __maybe_unused)
  {
  	struct perf_kvm_stat *kvm = container_of(tool, struct perf_kvm_stat, tool);
  
  	kvm->lost_events++;
  	return 0;

  }

  #endif

  static bool skip_sample(struct perf_kvm_stat *kvm,
  			struct perf_sample *sample)
  {
  	if (kvm->pid_list && intlist__find(kvm->pid_list, sample->pid) == NULL)
  		return true;
  
  	return false;
  }

  static int process_sample_event(struct perf_tool *tool,

  				union perf_event *event,
  				struct perf_sample *sample,

  				struct evsel *evsel,

  				struct machine *machine)
  {

  	int err = 0;

  	struct thread *thread;

  	struct perf_kvm_stat *kvm = container_of(tool, struct perf_kvm_stat,
  						 tool);

  	if (skip_sample(kvm, sample))
  		return 0;

  	thread = machine__findnew_thread(machine, sample->pid, sample->tid);

  	if (thread == NULL) {
  		pr_debug("problem processing %d event, skipping it.
  ",
  			event->header.type);
  		return -1;
  	}

  	if (!handle_kvm_event(kvm, thread, evsel, sample))

  		err = -1;

  	thread__put(thread);
  	return err;

  }

  static int cpu_isa_config(struct perf_kvm_stat *kvm)

  {

  	char buf[128], *cpuid;

  	int err;

  
  	if (kvm->live) {
  		err = get_cpuid(buf, sizeof(buf));
  		if (err != 0) {

  			pr_err("Failed to look up CPU type: %s
  ",
  			       str_error_r(err, buf, sizeof(buf)));
  			return -err;

  		}
  		cpuid = buf;
  	} else
  		cpuid = kvm->session->header.env.cpuid;

  	if (!cpuid) {
  		pr_err("Failed to look up CPU type
  ");
  		return -EINVAL;

  	}

  	err = cpu_isa_init(kvm, cpuid);
  	if (err == -ENOTSUP)
  		pr_err("CPU %s is not supported.
  ", cpuid);

  	return err;

  }
  
  static bool verify_vcpu(int vcpu)
  {
  	if (vcpu != -1 && vcpu < 0) {
  		pr_err("Invalid vcpu:%d.
  ", vcpu);
  		return false;
  	}
  
  	return true;
  }

  #ifdef HAVE_TIMERFD_SUPPORT

  /* keeping the max events to a modest level to keep
   * the processing of samples per mmap smooth.
   */
  #define PERF_KVM__MAX_EVENTS_PER_MMAP  25
  
  static s64 perf_kvm__mmap_read_idx(struct perf_kvm_stat *kvm, int idx,
  				   u64 *mmap_time)
  {

  	struct evlist *evlist = kvm->evlist;

  	union perf_event *event;

  	struct mmap *md;

  	u64 timestamp;

  	s64 n = 0;
  	int err;
  
  	*mmap_time = ULLONG_MAX;

  	md = &evlist->mmap[idx];

  	err = perf_mmap__read_init(&md->core);

  	if (err < 0)
  		return (err == -EAGAIN) ? 0 : -1;

  	while ((event = perf_mmap__read_event(&md->core)) != NULL) {

  		err = perf_evlist__parse_sample_timestamp(evlist, event, &timestamp);

  		if (err) {

  			perf_mmap__consume(&md->core);

  			pr_err("Failed to parse sample
  ");
  			return -1;
  		}

  		err = perf_session__queue_event(kvm->session, event, timestamp, 0);

  		/*

  		 * FIXME: Here we can't consume the event, as perf_session__queue_event will

  		 *        point to it, and it'll get possibly overwritten by the kernel.
  		 */

  		perf_mmap__consume(&md->core);

  		if (err) {
  			pr_err("Failed to enqueue sample: %d
  ", err);
  			return -1;
  		}
  
  		/* save time stamp of our first sample for this mmap */
  		if (n == 0)

  			*mmap_time = timestamp;

  
  		/* limit events per mmap handled all at once */
  		n++;
  		if (n == PERF_KVM__MAX_EVENTS_PER_MMAP)
  			break;
  	}

  	perf_mmap__read_done(&md->core);

  	return n;
  }
  
  static int perf_kvm__mmap_read(struct perf_kvm_stat *kvm)
  {
  	int i, err, throttled = 0;
  	s64 n, ntotal = 0;
  	u64 flush_time = ULLONG_MAX, mmap_time;

  	for (i = 0; i < kvm->evlist->core.nr_mmaps; i++) {

  		n = perf_kvm__mmap_read_idx(kvm, i, &mmap_time);
  		if (n < 0)
  			return -1;
  
  		/* flush time is going to be the minimum of all the individual
  		 * mmap times. Essentially, we flush all the samples queued up
  		 * from the last pass under our minimal start time -- that leaves
  		 * a very small race for samples to come in with a lower timestamp.
  		 * The ioctl to return the perf_clock timestamp should close the
  		 * race entirely.
  		 */
  		if (mmap_time < flush_time)
  			flush_time = mmap_time;
  
  		ntotal += n;
  		if (n == PERF_KVM__MAX_EVENTS_PER_MMAP)
  			throttled = 1;
  	}
  
  	/* flush queue after each round in which we processed events */
  	if (ntotal) {

  		struct ordered_events *oe = &kvm->session->ordered_events;
  
  		oe->next_flush = flush_time;
  		err = ordered_events__flush(oe, OE_FLUSH__ROUND);

  		if (err) {
  			if (kvm->lost_events)
  				pr_info("
  Lost events: %" PRIu64 "
  
  ",
  					kvm->lost_events);
  			return err;
  		}
  	}
  
  	return throttled;
  }
  
  static volatile int done;
  
  static void sig_handler(int sig __maybe_unused)
  {
  	done = 1;
  }
  
  static int perf_kvm__timerfd_create(struct perf_kvm_stat *kvm)
  {
  	struct itimerspec new_value;
  	int rc = -1;
  
  	kvm->timerfd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK);
  	if (kvm->timerfd < 0) {
  		pr_err("timerfd_create failed
  ");
  		goto out;
  	}
  
  	new_value.it_value.tv_sec = kvm->display_time;
  	new_value.it_value.tv_nsec = 0;
  	new_value.it_interval.tv_sec = kvm->display_time;
  	new_value.it_interval.tv_nsec = 0;
  
  	if (timerfd_settime(kvm->timerfd, 0, &new_value, NULL) != 0) {
  		pr_err("timerfd_settime failed: %d
  ", errno);
  		close(kvm->timerfd);
  		goto out;
  	}
  
  	rc = 0;
  out:
  	return rc;
  }
  
  static int perf_kvm__handle_timerfd(struct perf_kvm_stat *kvm)
  {
  	uint64_t c;
  	int rc;
  
  	rc = read(kvm->timerfd, &c, sizeof(uint64_t));
  	if (rc < 0) {
  		if (errno == EAGAIN)
  			return 0;
  
  		pr_err("Failed to read timer fd: %d
  ", errno);
  		return -1;
  	}
  
  	if (rc != sizeof(uint64_t)) {
  		pr_err("Error reading timer fd - invalid size returned
  ");
  		return -1;
  	}
  
  	if (c != 1)
  		pr_debug("Missed timer beats: %" PRIu64 "
  ", c-1);
  
  	/* update display */
  	sort_result(kvm);
  	print_result(kvm);
  
  	/* reset counts */
  	clear_events_cache_stats(kvm->kvm_events_cache);
  	kvm->total_count = 0;
  	kvm->total_time = 0;
  	kvm->lost_events = 0;
  
  	return 0;
  }
  
  static int fd_set_nonblock(int fd)
  {
  	long arg = 0;
  
  	arg = fcntl(fd, F_GETFL);
  	if (arg < 0) {
  		pr_err("Failed to get current flags for fd %d
  ", fd);
  		return -1;
  	}
  
  	if (fcntl(fd, F_SETFL, arg | O_NONBLOCK) < 0) {
  		pr_err("Failed to set non-block option on fd %d
  ", fd);
  		return -1;
  	}
  
  	return 0;
  }

  static int perf_kvm__handle_stdin(void)

  {
  	int c;

  	c = getc(stdin);

  	if (c == 'q')
  		return 1;
  
  	return 0;
  }
  
  static int kvm_events_live_report(struct perf_kvm_stat *kvm)
  {

  	int nr_stdin, ret, err = -EINVAL;

  	struct termios save;

  
  	/* live flag must be set first */
  	kvm->live = true;
  
  	ret = cpu_isa_config(kvm);
  	if (ret < 0)
  		return ret;
  
  	if (!verify_vcpu(kvm->trace_vcpu) ||
  	    !select_key(kvm) ||
  	    !register_kvm_events_ops(kvm)) {
  		goto out;
  	}

  	set_term_quiet_input(&save);

  	init_kvm_event_record(kvm);

  	signal(SIGINT, sig_handler);
  	signal(SIGTERM, sig_handler);

  	/* add timer fd */
  	if (perf_kvm__timerfd_create(kvm) < 0) {
  		err = -1;
  		goto out;
  	}

  	if (evlist__add_pollfd(kvm->evlist, kvm->timerfd) < 0)

  		goto out;

  	nr_stdin = evlist__add_pollfd(kvm->evlist, fileno(stdin));

  	if (nr_stdin < 0)

  		goto out;

  	if (fd_set_nonblock(fileno(stdin)) != 0)
  		goto out;
  
  	/* everything is good - enable the events and process */

  	evlist__enable(kvm->evlist);

  
  	while (!done) {

  		struct fdarray *fda = &kvm->evlist->core.pollfd;

  		int rc;
  
  		rc = perf_kvm__mmap_read(kvm);
  		if (rc < 0)
  			break;
  
  		err = perf_kvm__handle_timerfd(kvm);
  		if (err)
  			goto out;

  		if (fda->entries[nr_stdin].revents & POLLIN)

  			done = perf_kvm__handle_stdin();

  
  		if (!rc && !done)

  			err = evlist__poll(kvm->evlist, 100);

  	}

  	evlist__disable(kvm->evlist);

  
  	if (err == 0) {
  		sort_result(kvm);
  		print_result(kvm);
  	}
  
  out:
  	if (kvm->timerfd >= 0)
  		close(kvm->timerfd);

  	tcsetattr(0, TCSAFLUSH, &save);

  	return err;
  }
  
  static int kvm_live_open_events(struct perf_kvm_stat *kvm)
  {
  	int err, rc = -1;

  	struct evsel *pos;

  	struct evlist *evlist = kvm->evlist;

  	char sbuf[STRERR_BUFSIZE];

  	perf_evlist__config(evlist, &kvm->opts, NULL);

  
  	/*
  	 * Note: exclude_{guest,host} do not apply here.
  	 *       This command processes KVM tracepoints from host only
  	 */

  	evlist__for_each_entry(evlist, pos) {

  		struct perf_event_attr *attr = &pos->core.attr;

  
  		/* make sure these *are* set */

  		evsel__set_sample_bit(pos, TID);
  		evsel__set_sample_bit(pos, TIME);
  		evsel__set_sample_bit(pos, CPU);
  		evsel__set_sample_bit(pos, RAW);

  		/* make sure these are *not*; want as small a sample as possible */

  		evsel__reset_sample_bit(pos, PERIOD);
  		evsel__reset_sample_bit(pos, IP);
  		evsel__reset_sample_bit(pos, CALLCHAIN);
  		evsel__reset_sample_bit(pos, ADDR);
  		evsel__reset_sample_bit(pos, READ);

  		attr->mmap = 0;
  		attr->comm = 0;
  		attr->task = 0;
  
  		attr->sample_period = 1;
  
  		attr->watermark = 0;
  		attr->wakeup_events = 1000;
  
  		/* will enable all once we are ready */
  		attr->disabled = 1;
  	}

  	err = evlist__open(evlist);

  	if (err < 0) {

  		printf("Couldn't create the events: %s
  ",

  		       str_error_r(errno, sbuf, sizeof(sbuf)));

  		goto out;

  	}

  	if (evlist__mmap(evlist, kvm->opts.mmap_pages) < 0) {

  		ui__error("Failed to mmap the events: %s
  ",

  			  str_error_r(errno, sbuf, sizeof(sbuf)));

  		evlist__close(evlist);

  		goto out;
  	}
  
  	rc = 0;
  
  out:
  	return rc;

  }

  #endif

  static int read_events(struct perf_kvm_stat *kvm)

  {

  	int ret;

  	struct perf_tool eops = {
  		.sample			= process_sample_event,
  		.comm			= perf_event__process_comm,

  		.namespaces		= perf_event__process_namespaces,

  		.ordered_events		= true,

  	};

  	struct perf_data file = {

  		.path  = kvm->file_name,
  		.mode  = PERF_DATA_MODE_READ,
  		.force = kvm->force,

  	};

  
  	kvm->tool = eops;

  	kvm->session = perf_session__new(&file, false, &kvm->tool);

  	if (IS_ERR(kvm->session)) {

  		pr_err("Initializing perf session failed
  ");

  		return PTR_ERR(kvm->session);

  	}

  	symbol__init(&kvm->session->header.env);

  	if (!perf_session__has_traces(kvm->session, "kvm record")) {
  		ret = -EINVAL;
  		goto out_delete;
  	}

  
  	/*
  	 * Do not use 'isa' recorded in kvm_exit tracepoint since it is not
  	 * traced in the old kernel.
  	 */

  	ret = cpu_isa_config(kvm);

  	if (ret < 0)

  		goto out_delete;
  
  	ret = perf_session__process_events(kvm->session);

  out_delete:
  	perf_session__delete(kvm->session);
  	return ret;

  }

  static int parse_target_str(struct perf_kvm_stat *kvm)
  {

  	if (kvm->opts.target.pid) {
  		kvm->pid_list = intlist__new(kvm->opts.target.pid);

  		if (kvm->pid_list == NULL) {
  			pr_err("Error parsing process id string
  ");
  			return -EINVAL;
  		}
  	}
  
  	return 0;
  }

  static int kvm_events_report_vcpu(struct perf_kvm_stat *kvm)

  {
  	int ret = -EINVAL;

  	int vcpu = kvm->trace_vcpu;

  	if (parse_target_str(kvm) != 0)
  		goto exit;

  	if (!verify_vcpu(vcpu))
  		goto exit;

  	if (!select_key(kvm))

  		goto exit;

  	if (!register_kvm_events_ops(kvm))

  		goto exit;

  	init_kvm_event_record(kvm);

  	setup_pager();

  	ret = read_events(kvm);

  	if (ret)
  		goto exit;

  	sort_result(kvm);
  	print_result(kvm);

  exit:
  	return ret;
  }

  #define STRDUP_FAIL_EXIT(s)		\
  	({	char *_p;		\
  	_p = strdup(s);		\
  		if (!_p)		\
  			return -ENOMEM;	\
  		_p;			\
  	})

  int __weak setup_kvm_events_tp(struct perf_kvm_stat *kvm __maybe_unused)
  {
  	return 0;
  }

  static int
  kvm_events_record(struct perf_kvm_stat *kvm, int argc, const char **argv)

  {

  	unsigned int rec_argc, i, j, events_tp_size;

  	const char **rec_argv;

  	const char * const record_args[] = {
  		"record",
  		"-R",

  		"-m", "1024",
  		"-c", "1",
  	};

  	const char * const kvm_stat_record_usage[] = {
  		"perf kvm stat record [<options>]",
  		NULL
  	};

  	const char * const *events_tp;

  	int ret;

  	events_tp_size = 0;

  	ret = setup_kvm_events_tp(kvm);
  	if (ret < 0) {
  		pr_err("Unable to setup the kvm tracepoints
  ");
  		return ret;
  	}

  
  	for (events_tp = kvm_events_tp; *events_tp; events_tp++)
  		events_tp_size++;

  	rec_argc = ARRAY_SIZE(record_args) + argc + 2 +

  		   2 * events_tp_size;

  	rec_argv = calloc(rec_argc + 1, sizeof(char *));
  
  	if (rec_argv == NULL)
  		return -ENOMEM;
  
  	for (i = 0; i < ARRAY_SIZE(record_args); i++)
  		rec_argv[i] = STRDUP_FAIL_EXIT(record_args[i]);

  	for (j = 0; j < events_tp_size; j++) {

  		rec_argv[i++] = "-e";
  		rec_argv[i++] = STRDUP_FAIL_EXIT(kvm_events_tp[j]);
  	}

  	rec_argv[i++] = STRDUP_FAIL_EXIT("-o");

  	rec_argv[i++] = STRDUP_FAIL_EXIT(kvm->file_name);

  
  	for (j = 1; j < (unsigned int)argc; j++, i++)
  		rec_argv[i] = argv[j];

  	set_option_flag(record_options, 'e', "event", PARSE_OPT_HIDDEN);
  	set_option_flag(record_options, 0, "filter", PARSE_OPT_HIDDEN);
  	set_option_flag(record_options, 'R', "raw-samples", PARSE_OPT_HIDDEN);
  
  	set_option_flag(record_options, 'F', "freq", PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 0, "group", PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 'g', NULL, PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 0, "call-graph", PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 'd', "data", PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 'T', "timestamp", PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 'P', "period", PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 'n', "no-samples", PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 'N', "no-buildid-cache", PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 'B', "no-buildid", PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 'G', "cgroup", PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 'b', "branch-any", PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 'j', "branch-filter", PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 'W', "weight", PARSE_OPT_DISABLED);
  	set_option_flag(record_options, 0, "transaction", PARSE_OPT_DISABLED);
  
  	record_usage = kvm_stat_record_usage;

  	return cmd_record(i, rec_argv);

  }

  static int
  kvm_events_report(struct perf_kvm_stat *kvm, int argc, const char **argv)

  {
  	const struct option kvm_events_report_options[] = {
  		OPT_STRING(0, "event", &kvm->report_event, "report event",

  			   "event for reporting: vmexit, "
  			   "mmio (x86 only), ioport (x86 only)"),

  		OPT_INTEGER(0, "vcpu", &kvm->trace_vcpu,
  			    "vcpu id to report"),
  		OPT_STRING('k', "key", &kvm->sort_key, "sort-key",
  			    "key for sorting: sample(sort by samples number)"
  			    " time (sort by avg time)"),

  		OPT_STRING('p', "pid", &kvm->opts.target.pid, "pid",

  			   "analyze events only for given process id(s)"),

  		OPT_BOOLEAN('f', "force", &kvm->force, "don't complain, do it"),

  		OPT_END()
  	};

  	const char * const kvm_events_report_usage[] = {
  		"perf kvm stat report [<options>]",
  		NULL
  	};

  	if (argc) {
  		argc = parse_options(argc, argv,
  				     kvm_events_report_options,
  				     kvm_events_report_usage, 0);
  		if (argc)
  			usage_with_options(kvm_events_report_usage,
  					   kvm_events_report_options);
  	}

  	if (!kvm->opts.target.pid)
  		kvm->opts.target.system_wide = true;

  	return kvm_events_report_vcpu(kvm);

  }

  #ifdef HAVE_TIMERFD_SUPPORT

  static struct evlist *kvm_live_event_list(void)

  {

  	struct evlist *evlist;

  	char *tp, *name, *sys;

  	int err = -1;

  	const char * const *events_tp;

  	evlist = evlist__new();

  	if (evlist == NULL)
  		return NULL;

  	for (events_tp = kvm_events_tp; *events_tp; events_tp++) {

  		tp = strdup(*events_tp);

  		if (tp == NULL)
  			goto out;
  
  		/* split tracepoint into subsystem and name */
  		sys = tp;
  		name = strchr(tp, ':');
  		if (name == NULL) {
  			pr_err("Error parsing %s tracepoint: subsystem delimiter not found
  ",

  			       *events_tp);

  			free(tp);
  			goto out;
  		}
  		*name = '\0';
  		name++;

  		if (evlist__add_newtp(evlist, sys, name, NULL)) {

  			pr_err("Failed to add %s tracepoint to the list
  ", *events_tp);

  			free(tp);
  			goto out;
  		}
  
  		free(tp);
  	}
  
  	err = 0;
  
  out:
  	if (err) {

  		evlist__delete(evlist);

  		evlist = NULL;
  	}
  
  	return evlist;
  }
  
  static int kvm_events_live(struct perf_kvm_stat *kvm,
  			   int argc, const char **argv)
  {
  	char errbuf[BUFSIZ];
  	int err;
  
  	const struct option live_options[] = {
  		OPT_STRING('p', "pid", &kvm->opts.target.pid, "pid",
  			"record events on existing process id"),

  		OPT_CALLBACK('m', "mmap-pages", &kvm->opts.mmap_pages, "pages",
  			"number of mmap data pages",
  			perf_evlist__parse_mmap_pages),

  		OPT_INCR('v', "verbose", &verbose,
  			"be more verbose (show counter open errors, etc)"),
  		OPT_BOOLEAN('a', "all-cpus", &kvm->opts.target.system_wide,
  			"system-wide collection from all CPUs"),
  		OPT_UINTEGER('d', "display", &kvm->display_time,
  			"time in seconds between display updates"),
  		OPT_STRING(0, "event", &kvm->report_event, "report event",

  			"event for reporting: "
  			"vmexit, mmio (x86 only), ioport (x86 only)"),

  		OPT_INTEGER(0, "vcpu", &kvm->trace_vcpu,
  			"vcpu id to report"),
  		OPT_STRING('k', "key", &kvm->sort_key, "sort-key",
  			"key for sorting: sample(sort by samples number)"
  			" time (sort by avg time)"),

  		OPT_U64(0, "duration", &kvm->duration,

  			"show events other than"
  			" HLT (x86 only) or Wait state (s390 only)"
  			" that take longer than duration usecs"),

  		OPT_UINTEGER(0, "proc-map-timeout", &proc_map_timeout,

  				"per thread proc mmap processing timeout in ms"),

  		OPT_END()
  	};
  	const char * const live_usage[] = {
  		"perf kvm stat live [<options>]",
  		NULL
  	};

  	struct perf_data data = {

  		.mode = PERF_DATA_MODE_WRITE,
  	};

  
  
  	/* event handling */
  	kvm->tool.sample = process_sample_event;
  	kvm->tool.comm   = perf_event__process_comm;
  	kvm->tool.exit   = perf_event__process_exit;
  	kvm->tool.fork   = perf_event__process_fork;
  	kvm->tool.lost   = process_lost_event;

  	kvm->tool.namespaces  = perf_event__process_namespaces;

  	kvm->tool.ordered_events = true;

  	perf_tool__fill_defaults(&kvm->tool);
  
  	/* set defaults */
  	kvm->display_time = 1;
  	kvm->opts.user_interval = 1;
  	kvm->opts.mmap_pages = 512;
  	kvm->opts.target.uses_mmap = false;
  	kvm->opts.target.uid_str = NULL;
  	kvm->opts.target.uid = UINT_MAX;

  	symbol__init(NULL);

  	disable_buildid_cache();
  
  	use_browser = 0;

  
  	if (argc) {
  		argc = parse_options(argc, argv, live_options,
  				     live_usage, 0);
  		if (argc)
  			usage_with_options(live_usage, live_options);
  	}

  	kvm->duration *= NSEC_PER_USEC;   /* convert usec to nsec */

  	/*
  	 * target related setups
  	 */

  	err = target__validate(&kvm->opts.target);

  	if (err) {

  		target__strerror(&kvm->opts.target, err, errbuf, BUFSIZ);

  		ui__warning("%s", errbuf);
  	}

  	if (target__none(&kvm->opts.target))

  		kvm->opts.target.system_wide = true;
  
  
  	/*
  	 * generate the event list
  	 */

  	err = setup_kvm_events_tp(kvm);
  	if (err < 0) {
  		pr_err("Unable to setup the kvm tracepoints
  ");
  		return err;
  	}

  	kvm->evlist = kvm_live_event_list();
  	if (kvm->evlist == NULL) {
  		err = -1;
  		goto out;
  	}

  	if (perf_evlist__create_maps(kvm->evlist, &kvm->opts.target) < 0)
  		usage_with_options(live_usage, live_options);
  
  	/*
  	 * perf session
  	 */

  	kvm->session = perf_session__new(&data, false, &kvm->tool);

  	if (IS_ERR(kvm->session)) {
  		err = PTR_ERR(kvm->session);

  		goto out;
  	}
  	kvm->session->evlist = kvm->evlist;
  	perf_session__set_id_hdr_size(kvm->session);

  	ordered_events__set_copy_on_queue(&kvm->session->ordered_events, true);

  	machine__synthesize_threads(&kvm->session->machines.host, &kvm->opts.target,

  				    kvm->evlist->core.threads, false, 1);

  	err = kvm_live_open_events(kvm);
  	if (err)
  		goto out;
  
  	err = kvm_events_live_report(kvm);
  
  out:

  	perf_session__delete(kvm->session);

  	kvm->session = NULL;

  	evlist__delete(kvm->evlist);

  
  	return err;
  }

  #endif

  static void print_kvm_stat_usage(void)
  {
  	printf("Usage: perf kvm stat <command>
  
  ");
  
  	printf("# Available commands:
  ");
  	printf("\trecord: record kvm events
  ");
  	printf("\treport: report statistical data of kvm events
  ");

  	printf("\tlive:   live reporting of statistical data of kvm events
  ");

  
  	printf("
  Otherwise, it is the alias of 'perf stat':
  ");
  }

  static int kvm_cmd_stat(const char *file_name, int argc, const char **argv)

  {

  	struct perf_kvm_stat kvm = {
  		.file_name = file_name,
  
  		.trace_vcpu	= -1,
  		.report_event	= "vmexit",
  		.sort_key	= "sample",

  	};

  	if (argc == 1) {
  		print_kvm_stat_usage();
  		goto perf_stat;
  	}
  
  	if (!strncmp(argv[1], "rec", 3))

  		return kvm_events_record(&kvm, argc - 1, argv + 1);

  
  	if (!strncmp(argv[1], "rep", 3))

  		return kvm_events_report(&kvm, argc - 1 , argv + 1);

  #ifdef HAVE_TIMERFD_SUPPORT

  	if (!strncmp(argv[1], "live", 4))
  		return kvm_events_live(&kvm, argc - 1 , argv + 1);

  #endif

  perf_stat:

  	return cmd_stat(argc, argv);

  }

  #endif /* HAVE_KVM_STAT_SUPPORT */

  int __weak kvm_add_default_arch_event(int *argc __maybe_unused,
  					const char **argv __maybe_unused)
  {
  	return 0;
  }

  static int __cmd_record(const char *file_name, int argc, const char **argv)

  {

  	int rec_argc, i = 0, j, ret;

  	const char **rec_argv;

  	ret = kvm_add_default_arch_event(&argc, argv);
  	if (ret)
  		return -EINVAL;

  	rec_argc = argc + 2;
  	rec_argv = calloc(rec_argc + 1, sizeof(char *));
  	rec_argv[i++] = strdup("record");
  	rec_argv[i++] = strdup("-o");

  	rec_argv[i++] = strdup(file_name);

  	for (j = 1; j < argc; j++, i++)
  		rec_argv[i] = argv[j];
  
  	BUG_ON(i != rec_argc);

  	return cmd_record(i, rec_argv);

  }

  static int __cmd_report(const char *file_name, int argc, const char **argv)

  {
  	int rec_argc, i = 0, j;
  	const char **rec_argv;
  
  	rec_argc = argc + 2;
  	rec_argv = calloc(rec_argc + 1, sizeof(char *));
  	rec_argv[i++] = strdup("report");
  	rec_argv[i++] = strdup("-i");

  	rec_argv[i++] = strdup(file_name);

  	for (j = 1; j < argc; j++, i++)
  		rec_argv[i] = argv[j];
  
  	BUG_ON(i != rec_argc);

  	return cmd_report(i, rec_argv);

  }

  static int
  __cmd_buildid_list(const char *file_name, int argc, const char **argv)

  {
  	int rec_argc, i = 0, j;
  	const char **rec_argv;
  
  	rec_argc = argc + 2;
  	rec_argv = calloc(rec_argc + 1, sizeof(char *));
  	rec_argv[i++] = strdup("buildid-list");
  	rec_argv[i++] = strdup("-i");

  	rec_argv[i++] = strdup(file_name);

  	for (j = 1; j < argc; j++, i++)
  		rec_argv[i] = argv[j];
  
  	BUG_ON(i != rec_argc);

  	return cmd_buildid_list(i, rec_argv);

  }

  int cmd_kvm(int argc, const char **argv)

  {

  	const char *file_name = NULL;

  	const struct option kvm_options[] = {

  		OPT_STRING('i', "input", &file_name, "file",

  			   "Input file name"),

  		OPT_STRING('o', "output", &file_name, "file",

  			   "Output file name"),
  		OPT_BOOLEAN(0, "guest", &perf_guest,
  			    "Collect guest os data"),
  		OPT_BOOLEAN(0, "host", &perf_host,
  			    "Collect host os data"),
  		OPT_STRING(0, "guestmount", &symbol_conf.guestmount, "directory",
  			   "guest mount directory under which every guest os"
  			   " instance has a subdir"),
  		OPT_STRING(0, "guestvmlinux", &symbol_conf.default_guest_vmlinux_name,
  			   "file", "file saving guest os vmlinux"),
  		OPT_STRING(0, "guestkallsyms", &symbol_conf.default_guest_kallsyms,
  			   "file", "file saving guest os /proc/kallsyms"),
  		OPT_STRING(0, "guestmodules", &symbol_conf.default_guest_modules,
  			   "file", "file saving guest os /proc/modules"),

  		OPT_INCR('v', "verbose", &verbose,
  			    "be more verbose (show counter open errors, etc)"),

  		OPT_END()
  	};

  	const char *const kvm_subcommands[] = { "top", "record", "report", "diff",
  						"buildid-list", "stat", NULL };
  	const char *kvm_usage[] = { NULL, NULL };

  	perf_host  = 0;
  	perf_guest = 1;

  	argc = parse_options_subcommand(argc, argv, kvm_options, kvm_subcommands, kvm_usage,
  					PARSE_OPT_STOP_AT_NON_OPTION);

  	if (!argc)
  		usage_with_options(kvm_usage, kvm_options);
  
  	if (!perf_host)
  		perf_guest = 1;

  	if (!file_name) {

  		file_name = get_filename_for_perf_kvm();

  		if (!file_name) {

  			pr_err("Failed to allocate memory for filename
  ");
  			return -ENOMEM;
  		}

  	}
  
  	if (!strncmp(argv[0], "rec", 3))

  		return __cmd_record(file_name, argc, argv);

  	else if (!strncmp(argv[0], "rep", 3))

  		return __cmd_report(file_name, argc, argv);

  	else if (!strncmp(argv[0], "diff", 4))

  		return cmd_diff(argc, argv);

  	else if (!strncmp(argv[0], "top", 3))

  		return cmd_top(argc, argv);

  	else if (!strncmp(argv[0], "buildid-list", 12))

  		return __cmd_buildid_list(file_name, argc, argv);

  #ifdef HAVE_KVM_STAT_SUPPORT

  	else if (!strncmp(argv[0], "stat", 4))

  		return kvm_cmd_stat(file_name, argc, argv);

  #endif

  	else
  		usage_with_options(kvm_usage, kvm_options);
  
  	return 0;
  }