builtin-kvm.c

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// SPDX-License-Identifier: GPL-2.0
#include "builtin.h"
#include "perf.h"

#include "util/evsel.h"
#include "util/evlist.h"
#include "util/term.h"
#include "util/util.h"
#include "util/cache.h"
#include "util/symbol.h"
#include "util/thread.h"
#include "util/header.h"
#include "util/session.h"
#include "util/intlist.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/top.h"
#include "util/data.h"
#include "util/ordered-events.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/kernel.h>
#include <linux/time64.h>
#include <errno.h>
#include <inttypes.h>
#include <poll.h>
#include <termios.h>
#include <semaphore.h>
#include <signal.h>
#include <math.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
#include "util/kvm-stat.h"

void exit_event_get_key(struct perf_evsel *evsel,
            struct perf_sample *sample,
            struct event_key *key)
{
    key->info = 0;
    key->key = perf_evsel__intval(evsel, sample, kvm_exit_reason);
}

bool kvm_exit_event(struct perf_evsel *evsel)
{
    return !strcmp(evsel->name, kvm_exit_trace);
}

bool exit_event_begin(struct perf_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 perf_evsel *evsel)
{
    return !strcmp(evsel->name, kvm_entry_trace);
}

bool exit_event_end(struct perf_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\n",
        (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\n");
        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\n");
        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 perf_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.\n");
        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\n",
                 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 perf_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\n", __func__);
            return NULL;
        }

        vcpu_record->vcpu_id = perf_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 perf_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\n", 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:\n\n");
    else
        pr_info("VCPU %d:\n\n", 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("\n\n");
    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("\n\n");

    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("\n");
    }

    pr_info("\nTotal Samples:%" PRIu64 ", Total events handled time:%.2fus.\n\n",
        kvm->total_count, kvm->total_time / (double)NSEC_PER_USEC);

    if (kvm->lost_events)
        pr_info("\nLost events: %" PRIu64 "\n\n", 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 perf_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.\n",
            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[64], *cpuid;
    int err;

    if (kvm->live) {
        err = get_cpuid(buf, sizeof(buf));
        if (err != 0) {
            pr_err("Failed to look up CPU type\n");
            return err;
        }
        cpuid = buf;
    } else
        cpuid = kvm->session->header.env.cpuid;

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

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

    return err;
}

static bool verify_vcpu(int vcpu)
{
    if (vcpu != -1 && vcpu < 0) {
        pr_err("Invalid vcpu:%d.\n", 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 perf_evlist *evlist = kvm->evlist;
    union perf_event *event;
    struct perf_mmap *md;
    u64 timestamp;
    s64 n = 0;
    int err;

    *mmap_time = ULLONG_MAX;
    md = &evlist->mmap[idx];
    err = perf_mmap__read_init(md);
    if (err < 0)
        return (err == -EAGAIN) ? 0 : -1;

    while ((event = perf_mmap__read_event(md)) != NULL) {
        err = perf_evlist__parse_sample_timestamp(evlist, event, &timestamp);
        if (err) {
            perf_mmap__consume(md);
            pr_err("Failed to parse sample\n");
            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);

        if (err) {
            pr_err("Failed to enqueue sample: %d\n", 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);
    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->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("\nLost events: %" PRIu64 "\n\n",
                    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\n");
        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\n", 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\n", errno);
        return -1;
    }

    if (rc != sizeof(uint64_t)) {
        pr_err("Error reading timer fd - invalid size returned\n");
        return -1;
    }

    if (c != 1)
        pr_debug("Missed timer beats: %" PRIu64 "\n", 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\n", fd);
        return -1;
    }

    if (fcntl(fd, F_SETFL, arg | O_NONBLOCK) < 0) {
        pr_err("Failed to set non-block option on fd %d\n", 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 (perf_evlist__add_pollfd(kvm->evlist, kvm->timerfd) < 0)
        goto out;

    nr_stdin = perf_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 */
    perf_evlist__enable(kvm->evlist);

    while (!done) {
        struct fdarray *fda = &kvm->evlist->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 = fdarray__poll(fda, 100);
    }

    perf_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 perf_evsel *pos;
    struct perf_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->attr;

        /* make sure these *are* set */
        perf_evsel__set_sample_bit(pos, TID);
        perf_evsel__set_sample_bit(pos, TIME);
        perf_evsel__set_sample_bit(pos, CPU);
        perf_evsel__set_sample_bit(pos, RAW);
        /* make sure these are *not*; want as small a sample as possible */
        perf_evsel__reset_sample_bit(pos, PERIOD);
        perf_evsel__reset_sample_bit(pos, IP);
        perf_evsel__reset_sample_bit(pos, CALLCHAIN);
        perf_evsel__reset_sample_bit(pos, ADDR);
        perf_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 = perf_evlist__open(evlist);
    if (err < 0) {
        printf("Couldn't create the events: %s\n",
               str_error_r(errno, sbuf, sizeof(sbuf)));
        goto out;
    }

    if (perf_evlist__mmap(evlist, kvm->opts.mmap_pages) < 0) {
        ui__error("Failed to mmap the events: %s\n",
              str_error_r(errno, sbuf, sizeof(sbuf)));
        perf_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 = {
        .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 (!kvm->session) {
        pr_err("Initializing perf session failed\n");
        return -1;
    }

    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\n");
            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\n");
        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 perf_evlist *kvm_live_event_list(void)
{
    struct perf_evlist *evlist;
    char *tp, *name, *sys;
    int err = -1;
    const char * const *events_tp;

    evlist = perf_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\n",
                   *events_tp);
            free(tp);
            goto out;
        }
        *name = '\0';
        name++;

        if (perf_evlist__add_newtp(evlist, sys, name, NULL)) {
            pr_err("Failed to add %s tracepoint to the list\n", *events_tp);
            free(tp);
            goto out;
        }

        free(tp);
    }

    err = 0;

out:
    if (err) {
        perf_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", &kvm->opts.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;
    kvm->opts.proc_map_timeout = 500;

    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\n");
        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 (kvm->session == NULL) {
        err = -1;
        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->threads, false,
                    kvm->opts.proc_map_timeout, 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;
    perf_evlist__delete(kvm->evlist);

    return err;
}
#endif

static void print_kvm_stat_usage(void)
{
    printf("Usage: perf kvm stat <command>\n\n");

    printf("# Available commands:\n");
    printf("\trecord: record kvm events\n");
    printf("\treport: report statistical data of kvm events\n");
    printf("\tlive:   live reporting of statistical data of kvm events\n");

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

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 */

static int __cmd_record(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("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\n");
            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;
}