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

#include "util/evsel.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/parse-options.h"
#include "util/trace-event.h"
#include "util/debug.h"
#include "util/debugfs.h"
#include "util/tool.h"
#include "util/stat.h"

#include <sys/prctl.h>

#include <semaphore.h>
#include <pthread.h>
#include <math.h>

#if defined(__i386__) || defined(__x86_64__)
#include <asm/svm.h>
#include <asm/vmx.h>
#include <asm/kvm.h>

struct event_key {
        #define INVALID_KEY     (~0ULL)
        u64 key;
        int info;
};

struct kvm_event_stats {
        u64 time;
        struct stats stats;
};

struct kvm_event {
        struct list_head hash_entry;
        struct rb_node rb;

        struct event_key key;

        struct kvm_event_stats total;

        #define DEFAULT_VCPU_NUM 8
        int max_vcpu;
        struct kvm_event_stats *vcpu;
};

typedef int (*key_cmp_fun)(struct kvm_event*, struct kvm_event*, int);

struct kvm_event_key {
        const char *name;
        key_cmp_fun key;
};


struct perf_kvm_stat;

struct kvm_events_ops {
        bool (*is_begin_event)(struct perf_evsel *evsel,
                               struct perf_sample *sample,
                               struct event_key *key);
        bool (*is_end_event)(struct perf_evsel *evsel,
                             struct perf_sample *sample, struct event_key *key);
        void (*decode_key)(struct perf_kvm_stat *kvm, struct event_key *key,
                           char decode[20]);
        const char *name;
};

struct exit_reasons_table {
        unsigned long exit_code;
        const char *reason;
};

#define EVENTS_BITS             12
#define EVENTS_CACHE_SIZE       (1UL << EVENTS_BITS)

struct perf_kvm_stat {
        struct perf_tool    tool;
        struct perf_session *session;

        const char *file_name;
        const char *report_event;
        const char *sort_key;
        int trace_vcpu;

        struct exit_reasons_table *exit_reasons;
        int exit_reasons_size;
        const char *exit_reasons_isa;

        struct kvm_events_ops *events_ops;
        key_cmp_fun compare;
        struct list_head kvm_events_cache[EVENTS_CACHE_SIZE];
        u64 total_time;
        u64 total_count;

        struct rb_root result;
};


static 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, "exit_reason");
}

static bool kvm_exit_event(struct perf_evsel *evsel)
{
        return !strcmp(evsel->name, "kvm:kvm_exit");
}

static 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;
}

static bool kvm_entry_event(struct perf_evsel *evsel)
{
        return !strcmp(evsel->name, "kvm:kvm_entry");
}

static 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 struct exit_reasons_table vmx_exit_reasons[] = {
        VMX_EXIT_REASONS
};

static struct exit_reasons_table svm_exit_reasons[] = {
        SVM_EXIT_REASONS
};

static const char *get_exit_reason(struct perf_kvm_stat *kvm, u64 exit_code)
{
        int i = kvm->exit_reasons_size;
        struct exit_reasons_table *tbl = kvm->exit_reasons;

        while (i--) {
                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";
}

static void exit_event_decode_key(struct perf_kvm_stat *kvm,
                                  struct event_key *key,
                                  char decode[20])
{
        const char *exit_reason = get_exit_reason(kvm, key->key);

        scnprintf(decode, 20, "%s", exit_reason);
}

static struct kvm_events_ops exit_events = {
        .is_begin_event = exit_event_begin,
        .is_end_event = exit_event_end,
        .decode_key = exit_event_decode_key,
        .name = "VM-EXIT"
};

/*
 * For the mmio events, we treat:
 * the time of MMIO write: kvm_mmio(KVM_TRACE_MMIO_WRITE...) -> kvm_entry
 * the time of MMIO read: kvm_exit -> kvm_mmio(KVM_TRACE_MMIO_READ...).
 */
static void mmio_event_get_key(struct perf_evsel *evsel, struct perf_sample *sample,
                               struct event_key *key)
{
        key->key  = perf_evsel__intval(evsel, sample, "gpa");
        key->info = perf_evsel__intval(evsel, sample, "type");
}

#define KVM_TRACE_MMIO_READ_UNSATISFIED 0
#define KVM_TRACE_MMIO_READ 1
#define KVM_TRACE_MMIO_WRITE 2

static bool mmio_event_begin(struct perf_evsel *evsel,
                             struct perf_sample *sample, struct event_key *key)
{
        /* MMIO read begin event in kernel. */
        if (kvm_exit_event(evsel))
                return true;

        /* MMIO write begin event in kernel. */
        if (!strcmp(evsel->name, "kvm:kvm_mmio") &&
            perf_evsel__intval(evsel, sample, "type") == KVM_TRACE_MMIO_WRITE) {
                mmio_event_get_key(evsel, sample, key);
                return true;
        }

        return false;
}

static bool mmio_event_end(struct perf_evsel *evsel, struct perf_sample *sample,
                           struct event_key *key)
{
        /* MMIO write end event in kernel. */
        if (kvm_entry_event(evsel))
                return true;

        /* MMIO read end event in kernel.*/
        if (!strcmp(evsel->name, "kvm:kvm_mmio") &&
            perf_evsel__intval(evsel, sample, "type") == KVM_TRACE_MMIO_READ) {
                mmio_event_get_key(evsel, sample, key);
                return true;
        }

        return false;
}

static void mmio_event_decode_key(struct perf_kvm_stat *kvm __maybe_unused,
                                  struct event_key *key,
                                  char decode[20])
{
        scnprintf(decode, 20, "%#lx:%s", (unsigned long)key->key,
                                key->info == KVM_TRACE_MMIO_WRITE ? "W" : "R");
}

static struct kvm_events_ops mmio_events = {
        .is_begin_event = mmio_event_begin,
        .is_end_event = mmio_event_end,
        .decode_key = mmio_event_decode_key,
        .name = "MMIO Access"
};

 /* The time of emulation pio access is from kvm_pio to kvm_entry. */
static void ioport_event_get_key(struct perf_evsel *evsel,
                                 struct perf_sample *sample,
                                 struct event_key *key)
{
        key->key  = perf_evsel__intval(evsel, sample, "port");
        key->info = perf_evsel__intval(evsel, sample, "rw");
}

static bool ioport_event_begin(struct perf_evsel *evsel,
                               struct perf_sample *sample,
                               struct event_key *key)
{
        if (!strcmp(evsel->name, "kvm:kvm_pio")) {
                ioport_event_get_key(evsel, sample, key);
                return true;
        }

        return false;
}

static bool ioport_event_end(struct perf_evsel *evsel,
                             struct perf_sample *sample __maybe_unused,
                             struct event_key *key __maybe_unused)
{
        return kvm_entry_event(evsel);
}

static void ioport_event_decode_key(struct perf_kvm_stat *kvm __maybe_unused,
                                    struct event_key *key,
                                    char decode[20])
{
        scnprintf(decode, 20, "%#llx:%s", (unsigned long long)key->key,
                                key->info ? "POUT" : "PIN");
}

static struct kvm_events_ops ioport_events = {
        .is_begin_event = ioport_event_begin,
        .is_end_event = ioport_event_end,
        .decode_key = ioport_event_decode_key,
        .name = "IO Port Access"
};

static bool register_kvm_events_ops(struct perf_kvm_stat *kvm)
{
        bool ret = true;

        if (!strcmp(kvm->report_event, "vmexit"))
                kvm->events_ops = &exit_events;
        else if (!strcmp(kvm->report_event, "mmio"))
                kvm->events_ops = &mmio_events;
        else if (!strcmp(kvm->report_event, "ioport"))
                kvm->events_ops = &ioport_events;
        else {
                pr_err("Unknown report event:%s\n", kvm->report_event);
                ret = false;
        }

        return ret;
}

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]);
}

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;

        if (vcpu_id < event->max_vcpu)
                return true;

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

        event->vcpu = realloc(event->vcpu,
                              event->max_vcpu * sizeof(*event->vcpu));
        if (!event->vcpu) {
                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;
        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 handle_end_event(struct perf_kvm_stat *kvm,
                             struct vcpu_event_record *vcpu_record,
                             struct event_key *key,
                             u64 timestamp)
{
        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;

        BUG_ON(timestamp < time_begin);

        time_diff = timestamp - time_begin;
        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 && 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");
                thread->priv = vcpu_record;
        }

        return thread->priv;
}

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};

        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 (kvm->events_ops->is_end_event(evsel, sample, &key))
                return handle_end_event(kvm, vcpu_record, &key, sample->time);

        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);

#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(int vcpu)
{
        pr_info("Analyze events for ");

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

static void print_result(struct perf_kvm_stat *kvm)
{
        char decode[20];
        struct kvm_event *event;
        int vcpu = kvm->trace_vcpu;

        pr_info("\n\n");
        print_vcpu_info(vcpu);
        pr_info("%20s ", kvm->events_ops->name);
        pr_info("%10s ", "Samples");
        pr_info("%9s ", "Samples%");

        pr_info("%9s ", "Time%");
        pr_info("%16s ", "Avg time");
        pr_info("\n\n");

        while ((event = pop_from_result(&kvm->result))) {
                u64 ecount, etime;

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

                kvm->events_ops->decode_key(kvm, &event->key, decode);
                pr_info("%20s ", 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 ( +-%7.2f%% )", (double)etime / ecount/1e3,
                        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 / 1e3);
}

static int process_sample_event(struct perf_tool *tool,
                                union perf_event *event,
                                struct perf_sample *sample,
                                struct perf_evsel *evsel,
                                struct machine *machine)
{
        struct thread *thread = machine__findnew_thread(machine, sample->tid);
        struct perf_kvm_stat *kvm = container_of(tool, struct perf_kvm_stat,
                                                 tool);

        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))
                return -1;

        return 0;
}

static int get_cpu_isa(struct perf_session *session)
{
        char *cpuid = session->header.env.cpuid;
        int isa;

        if (strstr(cpuid, "Intel"))
                isa = 1;
        else if (strstr(cpuid, "AMD"))
                isa = 0;
        else {
                pr_err("CPU %s is not supported.\n", cpuid);
                isa = -ENOTSUP;
        }

        return isa;
}

static int read_events(struct perf_kvm_stat *kvm)
{
        int ret;

        struct perf_tool eops = {
                .sample                 = process_sample_event,
                .comm                   = perf_event__process_comm,
                .ordered_samples        = true,
        };

        kvm->tool = eops;
        kvm->session = perf_session__new(kvm->file_name, O_RDONLY, 0, false,
                                         &kvm->tool);
        if (!kvm->session) {
                pr_err("Initializing perf session failed\n");
                return -EINVAL;
        }

        if (!perf_session__has_traces(kvm->session, "kvm record"))
                return -EINVAL;

        /*
         * Do not use 'isa' recorded in kvm_exit tracepoint since it is not
         * traced in the old kernel.
         */
        ret = get_cpu_isa(kvm->session);

        if (ret < 0)
                return ret;

        if (ret == 1) {
                kvm->exit_reasons = vmx_exit_reasons;
                kvm->exit_reasons_size = ARRAY_SIZE(vmx_exit_reasons);
                kvm->exit_reasons_isa = "VMX";
        }

        return perf_session__process_events(kvm->session, &kvm->tool);
}

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

        return true;
}

static int kvm_events_report_vcpu(struct perf_kvm_stat *kvm)
{
        int ret = -EINVAL;
        int vcpu = kvm->trace_vcpu;

        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;
}

static const char * const record_args[] = {
        "record",
        "-R",
        "-f",
        "-m", "1024",
        "-c", "1",
        "-e", "kvm:kvm_entry",
        "-e", "kvm:kvm_exit",
        "-e", "kvm:kvm_mmio",
        "-e", "kvm:kvm_pio",
};

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

static int
kvm_events_record(struct perf_kvm_stat *kvm, int argc, const char **argv)
{
        unsigned int rec_argc, i, j;
        const char **rec_argv;

        rec_argc = ARRAY_SIZE(record_args) + argc + 2;
        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]);

        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];

        return cmd_record(i, rec_argv, NULL);
}

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, ioport"),
                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_END()
        };

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

        symbol__init();

        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);
        }

        return kvm_events_report_vcpu(kvm);
}

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("\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",

                .exit_reasons = svm_exit_reasons,
                .exit_reasons_size = ARRAY_SIZE(svm_exit_reasons),
                .exit_reasons_isa = "SVM",
        };

        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);

perf_stat:
        return cmd_stat(argc, argv, NULL);
}
#endif

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, NULL);
}

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, NULL);
}

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, NULL);
}

int cmd_kvm(int argc, const char **argv, const char *prefix __maybe_unused)
{
        const char *file_name;

        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_END()
        };


        const char * const kvm_usage[] = {

                "perf kvm [<options>] {top|record|report|diff|buildid-list|stat}",
                NULL
        };

        perf_host  = 0;
        perf_guest = 1;

        argc = parse_options(argc, argv, kvm_options, 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) {
                if (perf_host && !perf_guest)
                        file_name = strdup("perf.data.host");
                else if (!perf_host && perf_guest)
                        file_name = strdup("perf.data.guest");
                else
                        file_name = strdup("perf.data.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, NULL);
        else if (!strncmp(argv[0], "top", 3))
                return cmd_top(argc, argv, NULL);
        else if (!strncmp(argv[0], "buildid-list", 12))
                return __cmd_buildid_list(file_name, argc, argv);
#if defined(__i386__) || defined(__x86_64__)
        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;
}