// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include "util/kvm-stat.h"
#include "util/parse-events.h"
#include "util/debug.h"
#include "util/evsel.h"
#include "util/evlist.h"
#include "util/pmu.h"

#include "book3s_hv_exits.h"
#include "book3s_hcalls.h"
#include <subcmd/parse-options.h>

#define NR_TPS 4

const char *vcpu_id_str = "vcpu_id";
const int decode_str_len = 40;
const char *kvm_entry_trace = "kvm_hv:kvm_guest_enter";
const char *kvm_exit_trace = "kvm_hv:kvm_guest_exit";

define_exit_reasons_table(hv_exit_reasons, kvm_trace_symbol_exit);
define_exit_reasons_table(hcall_reasons, kvm_trace_symbol_hcall);

/* Tracepoints specific to ppc_book3s_hv */
const char *ppc_book3s_hv_kvm_tp[] = {
        "kvm_hv:kvm_guest_enter",
        "kvm_hv:kvm_guest_exit",
        "kvm_hv:kvm_hcall_enter",
        "kvm_hv:kvm_hcall_exit",
        NULL,
};

/* 1 extra placeholder for NULL */
const char *kvm_events_tp[NR_TPS + 1];
const char *kvm_exit_reason;

static void hcall_event_get_key(struct evsel *evsel,
                                struct perf_sample *sample,
                                struct event_key *key)
{
        key->info = 0;
        key->key = evsel__intval(evsel, sample, "req");
}

static const char *get_hcall_exit_reason(u64 exit_code)
{
        struct exit_reasons_table *tbl = hcall_reasons;

        while (tbl->reason != NULL) {
                if (tbl->exit_code == exit_code)
                        return tbl->reason;
                tbl++;
        }

        pr_debug("Unknown hcall code: %lld\n",
               (unsigned long long)exit_code);
        return "UNKNOWN";
}

static bool hcall_event_end(struct evsel *evsel,
                            struct perf_sample *sample __maybe_unused,
                            struct event_key *key __maybe_unused)
{
        return (!strcmp(evsel->name, kvm_events_tp[3]));
}

static bool hcall_event_begin(struct evsel *evsel,
                              struct perf_sample *sample, struct event_key *key)
{
        if (!strcmp(evsel->name, kvm_events_tp[2])) {
                hcall_event_get_key(evsel, sample, key);
                return true;
        }

        return false;
}
static void hcall_event_decode_key(struct perf_kvm_stat *kvm __maybe_unused,
                                   struct event_key *key,
                                   char *decode)
{
        const char *hcall_reason = get_hcall_exit_reason(key->key);

        scnprintf(decode, decode_str_len, "%s", hcall_reason);
}

static struct kvm_events_ops hcall_events = {
        .is_begin_event = hcall_event_begin,
        .is_end_event = hcall_event_end,
        .decode_key = hcall_event_decode_key,
        .name = "HCALL-EVENT",
};

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"
};

struct kvm_reg_events_ops kvm_reg_events_ops[] = {
        { .name = "vmexit", .ops = &exit_events },
        { .name = "hcall", .ops = &hcall_events },
        { NULL, NULL },
};

const char * const kvm_skip_events[] = {
        NULL,
};


static int is_tracepoint_available(const char *str, struct evlist *evlist)
{
        struct parse_events_error err;
        int ret;

        bzero(&err, sizeof(err));
        ret = parse_events(evlist, str, &err);
        if (err.str)
                parse_events_print_error(&err, "tracepoint");
        return ret;
}

static int ppc__setup_book3s_hv(struct perf_kvm_stat *kvm,
                                struct evlist *evlist)
{
        const char **events_ptr;
        int i, nr_tp = 0, err = -1;

        /* Check for book3s_hv tracepoints */
        for (events_ptr = ppc_book3s_hv_kvm_tp; *events_ptr; events_ptr++) {
                err = is_tracepoint_available(*events_ptr, evlist);
                if (err)
                        return -1;
                nr_tp++;
        }

        for (i = 0; i < nr_tp; i++)
                kvm_events_tp[i] = ppc_book3s_hv_kvm_tp[i];

        kvm_events_tp[i] = NULL;
        kvm_exit_reason = "trap";
        kvm->exit_reasons = hv_exit_reasons;
        kvm->exit_reasons_isa = "HV";

        return 0;
}

/* Wrapper to setup kvm tracepoints */
static int ppc__setup_kvm_tp(struct perf_kvm_stat *kvm)
{
        struct evlist *evlist = evlist__new();

        if (evlist == NULL)
                return -ENOMEM;

        /* Right now, only supported on book3s_hv */
        return ppc__setup_book3s_hv(kvm, evlist);
}

int setup_kvm_events_tp(struct perf_kvm_stat *kvm)
{
        return ppc__setup_kvm_tp(kvm);
}

int cpu_isa_init(struct perf_kvm_stat *kvm, const char *cpuid __maybe_unused)
{
        int ret;

        ret = ppc__setup_kvm_tp(kvm);
        if (ret) {
                kvm->exit_reasons = NULL;
                kvm->exit_reasons_isa = NULL;
        }

        return ret;
}

/*
 * In case of powerpc architecture, pmu registers are programmable
 * by guest kernel. So monitoring guest via host may not provide
 * valid samples with default 'cycles' event. It is better to use
 * 'trace_imc/trace_cycles' event for guest profiling, since it
 * can track the guest instruction pointer in the trace-record.
 *
 * Function to parse the arguments and return appropriate values.
 */
int kvm_add_default_arch_event(int *argc, const char **argv)
{
        const char **tmp;
        bool event = false;
        int i, j = *argc;

        const struct option event_options[] = {
                OPT_BOOLEAN('e', "event", &event, NULL),
                OPT_END()
        };

        tmp = calloc(j + 1, sizeof(char *));
        if (!tmp)
                return -EINVAL;

        for (i = 0; i < j; i++)
                tmp[i] = argv[i];

        parse_options(j, tmp, event_options, NULL, PARSE_OPT_KEEP_UNKNOWN);
        if (!event) {
                if (pmu_have_event("trace_imc", "trace_cycles")) {
                        argv[j++] = strdup("-e");
                        argv[j++] = strdup("trace_imc/trace_cycles/");
                        *argc += 2;
                } else {
                        free(tmp);
                        return -EINVAL;
                }
        }

        free(tmp);
        return 0;
}