kvm-stat.c

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

#include "book3s_hv_exits.h"
#include "book3s_hcalls.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 perf_evsel *evsel,
                struct perf_sample *sample,
                struct event_key *key)
{
    key->info = 0;
    key->key = perf_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 perf_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 perf_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 perf_evlist *evlist)
{
    struct parse_events_error err;
    int ret;

    err.str = NULL;
    ret = parse_events(evlist, str, &err);
    if (err.str)
        pr_err("%s : %s\n", str, err.str);
    return ret;
}

static int ppc__setup_book3s_hv(struct perf_kvm_stat *kvm,
                struct perf_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 perf_evlist *evlist = perf_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;
}