perf tools: Propagate get_cpuid() error

[mirror_ubuntu-focal-kernel.git] / tools / perf / builtin-kvm.c

// 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>

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 = perf_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\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 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 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 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 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[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\n",
                               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\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 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);
        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->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("\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 (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 = fdarray__poll(fda, 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 */
                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 = evlist__open(evlist);
        if (err < 0) {
                printf("Couldn't create the events: %s\n",
                       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\n",
                          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\n");
                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\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 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\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) {
                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\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 (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>\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 */

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\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;
}