root/tools/perf/util/intel-bts.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * intel-bts.c: Intel Processor Trace support
 * Copyright (c) 2013-2015, Intel Corporation.
 */

#include <endian.h>
#include <errno.h>
#include <byteswap.h>
#include <inttypes.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/log2.h>
#include <linux/zalloc.h>

#include "color.h"
#include "evsel.h"
#include "evlist.h"
#include "machine.h"
#include "symbol.h"
#include "session.h"
#include "tool.h"
#include "thread.h"
#include "thread-stack.h"
#include "debug.h"
#include "tsc.h"
#include "auxtrace.h"
#include "intel-pt-decoder/intel-pt-insn-decoder.h"
#include "intel-bts.h"
#include "util/synthetic-events.h"

#define MAX_TIMESTAMP (~0ULL)

#define INTEL_BTS_ERR_NOINSN  5
#define INTEL_BTS_ERR_LOST    9

#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
#define le64_to_cpu bswap_64
#else
#define le64_to_cpu
#endif

struct intel_bts {
        struct auxtrace                 auxtrace;
        struct auxtrace_queues          queues;
        struct auxtrace_heap            heap;
        u32                             auxtrace_type;
        struct perf_session             *session;
        struct machine                  *machine;
        bool                            sampling_mode;
        bool                            snapshot_mode;
        bool                            data_queued;
        u32                             pmu_type;
        struct perf_tsc_conversion      tc;
        bool                            cap_user_time_zero;
        struct itrace_synth_opts        synth_opts;
        bool                            sample_branches;
        u32                             branches_filter;
        u64                             branches_sample_type;
        u64                             branches_id;
        size_t                          branches_event_size;
        unsigned long                   num_events;
};

struct intel_bts_queue {
        struct intel_bts        *bts;
        unsigned int            queue_nr;
        struct auxtrace_buffer  *buffer;
        bool                    on_heap;
        bool                    done;
        pid_t                   pid;
        pid_t                   tid;
        int                     cpu;
        u64                     time;
        struct intel_pt_insn    intel_pt_insn;
        u32                     sample_flags;
};

struct branch {
        u64 from;
        u64 to;
        u64 misc;
};

static void intel_bts_dump(struct intel_bts *bts __maybe_unused,
                           unsigned char *buf, size_t len)
{
        struct branch *branch;
        size_t i, pos = 0, br_sz = sizeof(struct branch), sz;
        const char *color = PERF_COLOR_BLUE;

        color_fprintf(stdout, color,
                      ". ... Intel BTS data: size %zu bytes\n",
                      len);

        while (len) {
                if (len >= br_sz)
                        sz = br_sz;
                else
                        sz = len;
                printf(".");
                color_fprintf(stdout, color, "  %08zx: ", pos);
                for (i = 0; i < sz; i++)
                        color_fprintf(stdout, color, " %02x", buf[i]);
                for (; i < br_sz; i++)
                        color_fprintf(stdout, color, "   ");
                if (len >= br_sz) {
                        branch = (struct branch *)buf;
                        color_fprintf(stdout, color, " %"PRIx64" -> %"PRIx64" %s\n",
                                      le64_to_cpu(branch->from),
                                      le64_to_cpu(branch->to),
                                      le64_to_cpu(branch->misc) & 0x10 ?
                                                        "pred" : "miss");
                } else {
                        color_fprintf(stdout, color, " Bad record!\n");
                }
                pos += sz;
                buf += sz;
                len -= sz;
        }
}

static void intel_bts_dump_event(struct intel_bts *bts, unsigned char *buf,
                                 size_t len)
{
        printf(".\n");
        intel_bts_dump(bts, buf, len);
}

static int intel_bts_lost(struct intel_bts *bts, struct perf_sample *sample)
{
        union perf_event event;
        int err;

        auxtrace_synth_error(&event.auxtrace_error, PERF_AUXTRACE_ERROR_ITRACE,
                             INTEL_BTS_ERR_LOST, sample->cpu, sample->pid,
                             sample->tid, 0, "Lost trace data", sample->time);

        err = perf_session__deliver_synth_event(bts->session, &event, NULL);
        if (err)
                pr_err("Intel BTS: failed to deliver error event, error %d\n",
                       err);

        return err;
}

static struct intel_bts_queue *intel_bts_alloc_queue(struct intel_bts *bts,
                                                     unsigned int queue_nr)
{
        struct intel_bts_queue *btsq;

        btsq = zalloc(sizeof(struct intel_bts_queue));
        if (!btsq)
                return NULL;

        btsq->bts = bts;
        btsq->queue_nr = queue_nr;
        btsq->pid = -1;
        btsq->tid = -1;
        btsq->cpu = -1;

        return btsq;
}

static int intel_bts_setup_queue(struct intel_bts *bts,
                                 struct auxtrace_queue *queue,
                                 unsigned int queue_nr)
{
        struct intel_bts_queue *btsq = queue->priv;

        if (list_empty(&queue->head))
                return 0;

        if (!btsq) {
                btsq = intel_bts_alloc_queue(bts, queue_nr);
                if (!btsq)
                        return -ENOMEM;
                queue->priv = btsq;

                if (queue->cpu != -1)
                        btsq->cpu = queue->cpu;
                btsq->tid = queue->tid;
        }

        if (bts->sampling_mode)
                return 0;

        if (!btsq->on_heap && !btsq->buffer) {
                int ret;

                btsq->buffer = auxtrace_buffer__next(queue, NULL);
                if (!btsq->buffer)
                        return 0;

                ret = auxtrace_heap__add(&bts->heap, queue_nr,
                                         btsq->buffer->reference);
                if (ret)
                        return ret;
                btsq->on_heap = true;
        }

        return 0;
}

static int intel_bts_setup_queues(struct intel_bts *bts)
{
        unsigned int i;
        int ret;

        for (i = 0; i < bts->queues.nr_queues; i++) {
                ret = intel_bts_setup_queue(bts, &bts->queues.queue_array[i],
                                            i);
                if (ret)
                        return ret;
        }
        return 0;
}

static inline int intel_bts_update_queues(struct intel_bts *bts)
{
        if (bts->queues.new_data) {
                bts->queues.new_data = false;
                return intel_bts_setup_queues(bts);
        }
        return 0;
}

static unsigned char *intel_bts_find_overlap(unsigned char *buf_a, size_t len_a,
                                             unsigned char *buf_b, size_t len_b)
{
        size_t offs, len;

        if (len_a > len_b)
                offs = len_a - len_b;
        else
                offs = 0;

        for (; offs < len_a; offs += sizeof(struct branch)) {
                len = len_a - offs;
                if (!memcmp(buf_a + offs, buf_b, len))
                        return buf_b + len;
        }

        return buf_b;
}

static int intel_bts_do_fix_overlap(struct auxtrace_queue *queue,
                                    struct auxtrace_buffer *b)
{
        struct auxtrace_buffer *a;
        void *start;

        if (b->list.prev == &queue->head)
                return 0;
        a = list_entry(b->list.prev, struct auxtrace_buffer, list);
        start = intel_bts_find_overlap(a->data, a->size, b->data, b->size);
        if (!start)
                return -EINVAL;
        b->use_size = b->data + b->size - start;
        b->use_data = start;
        return 0;
}

static inline u8 intel_bts_cpumode(struct intel_bts *bts, uint64_t ip)
{
        return machine__kernel_ip(bts->machine, ip) ?
               PERF_RECORD_MISC_KERNEL :
               PERF_RECORD_MISC_USER;
}

static int intel_bts_synth_branch_sample(struct intel_bts_queue *btsq,
                                         struct branch *branch)
{
        int ret;
        struct intel_bts *bts = btsq->bts;
        union perf_event event;
        struct perf_sample sample;

        if (bts->synth_opts.initial_skip &&
            bts->num_events++ <= bts->synth_opts.initial_skip)
                return 0;

        perf_sample__init(&sample, /*all=*/true);
        sample.ip = le64_to_cpu(branch->from);
        sample.cpumode = intel_bts_cpumode(bts, sample.ip);
        sample.pid = btsq->pid;
        sample.tid = btsq->tid;
        sample.addr = le64_to_cpu(branch->to);
        sample.id = btsq->bts->branches_id;
        sample.stream_id = btsq->bts->branches_id;
        sample.period = 1;
        sample.cpu = btsq->cpu;
        sample.flags = btsq->sample_flags;
        sample.insn_len = btsq->intel_pt_insn.length;
        memcpy(sample.insn, btsq->intel_pt_insn.buf, INTEL_PT_INSN_BUF_SZ);

        event.sample.header.type = PERF_RECORD_SAMPLE;
        event.sample.header.misc = sample.cpumode;
        event.sample.header.size = sizeof(struct perf_event_header);

        if (bts->synth_opts.inject) {
                event.sample.header.size = bts->branches_event_size;
                ret = perf_event__synthesize_sample(&event,
                                                    bts->branches_sample_type,
                                                    0, &sample);
                if (ret)
                        return ret;
        }

        ret = perf_session__deliver_synth_event(bts->session, &event, &sample);
        if (ret)
                pr_err("Intel BTS: failed to deliver branch event, error %d\n",
                       ret);

        perf_sample__exit(&sample);
        return ret;
}

static int intel_bts_get_next_insn(struct intel_bts_queue *btsq, u64 ip)
{
        struct machine *machine = btsq->bts->machine;
        struct thread *thread;
        unsigned char buf[INTEL_PT_INSN_BUF_SZ];
        ssize_t len;
        bool x86_64;
        int err = -1;

        thread = machine__find_thread(machine, -1, btsq->tid);
        if (!thread)
                return -1;

        len = thread__memcpy(thread, machine, buf, ip, INTEL_PT_INSN_BUF_SZ, &x86_64);
        if (len <= 0)
                goto out_put;

        if (intel_pt_get_insn(buf, len, x86_64, &btsq->intel_pt_insn))
                goto out_put;

        err = 0;
out_put:
        thread__put(thread);
        return err;
}

static int intel_bts_synth_error(struct intel_bts *bts, int cpu, pid_t pid,
                                 pid_t tid, u64 ip)
{
        union perf_event event;
        int err;

        auxtrace_synth_error(&event.auxtrace_error, PERF_AUXTRACE_ERROR_ITRACE,
                             INTEL_BTS_ERR_NOINSN, cpu, pid, tid, ip,
                             "Failed to get instruction", 0);

        err = perf_session__deliver_synth_event(bts->session, &event, NULL);
        if (err)
                pr_err("Intel BTS: failed to deliver error event, error %d\n",
                       err);

        return err;
}

static int intel_bts_get_branch_type(struct intel_bts_queue *btsq,
                                     struct branch *branch)
{
        int err;

        if (!branch->from) {
                if (branch->to)
                        btsq->sample_flags = PERF_IP_FLAG_BRANCH |
                                             PERF_IP_FLAG_TRACE_BEGIN;
                else
                        btsq->sample_flags = 0;
                btsq->intel_pt_insn.length = 0;
        } else if (!branch->to) {
                btsq->sample_flags = PERF_IP_FLAG_BRANCH |
                                     PERF_IP_FLAG_TRACE_END;
                btsq->intel_pt_insn.length = 0;
        } else {
                err = intel_bts_get_next_insn(btsq, branch->from);
                if (err) {
                        btsq->sample_flags = 0;
                        btsq->intel_pt_insn.length = 0;
                        if (!btsq->bts->synth_opts.errors)
                                return 0;
                        err = intel_bts_synth_error(btsq->bts, btsq->cpu,
                                                    btsq->pid, btsq->tid,
                                                    branch->from);
                        return err;
                }
                btsq->sample_flags = intel_pt_insn_type(btsq->intel_pt_insn.op);
                /* Check for an async branch into the kernel */
                if (!machine__kernel_ip(btsq->bts->machine, branch->from) &&
                    machine__kernel_ip(btsq->bts->machine, branch->to) &&
                    btsq->sample_flags != (PERF_IP_FLAG_BRANCH |
                                           PERF_IP_FLAG_CALL |
                                           PERF_IP_FLAG_SYSCALLRET))
                        btsq->sample_flags = PERF_IP_FLAG_BRANCH |
                                             PERF_IP_FLAG_CALL |
                                             PERF_IP_FLAG_ASYNC |
                                             PERF_IP_FLAG_INTERRUPT;
        }

        return 0;
}

static int intel_bts_process_buffer(struct intel_bts_queue *btsq,
                                    struct auxtrace_buffer *buffer,
                                    struct thread *thread)
{
        struct branch *branch;
        size_t sz, bsz = sizeof(struct branch);
        u32 filter = btsq->bts->branches_filter;
        int err = 0;

        if (buffer->use_data) {
                sz = buffer->use_size;
                branch = buffer->use_data;
        } else {
                sz = buffer->size;
                branch = buffer->data;
        }

        if (!btsq->bts->sample_branches)
                return 0;

        for (; sz > bsz; branch += 1, sz -= bsz) {
                if (!branch->from && !branch->to)
                        continue;
                intel_bts_get_branch_type(btsq, branch);
                if (btsq->bts->synth_opts.thread_stack)
                        thread_stack__event(thread, btsq->cpu, btsq->sample_flags,
                                            le64_to_cpu(branch->from),
                                            le64_to_cpu(branch->to),
                                            btsq->intel_pt_insn.length,
                                            buffer->buffer_nr + 1, true, 0, 0);
                if (filter && !(filter & btsq->sample_flags))
                        continue;
                err = intel_bts_synth_branch_sample(btsq, branch);
                if (err)
                        break;
        }
        return err;
}

static int intel_bts_process_queue(struct intel_bts_queue *btsq, u64 *timestamp)
{
        struct auxtrace_buffer *buffer = btsq->buffer, *old_buffer = buffer;
        struct auxtrace_queue *queue;
        struct thread *thread;
        int err;

        if (btsq->done)
                return 1;

        if (btsq->pid == -1) {
                thread = machine__find_thread(btsq->bts->machine, -1,
                                              btsq->tid);
                if (thread)
                        btsq->pid = thread__pid(thread);
        } else {
                thread = machine__findnew_thread(btsq->bts->machine, btsq->pid,
                                                 btsq->tid);
        }

        queue = &btsq->bts->queues.queue_array[btsq->queue_nr];

        if (!buffer)
                buffer = auxtrace_buffer__next(queue, NULL);

        if (!buffer) {
                if (!btsq->bts->sampling_mode)
                        btsq->done = 1;
                err = 1;
                goto out_put;
        }

        /* Currently there is no support for split buffers */
        if (buffer->consecutive) {
                err = -EINVAL;
                goto out_put;
        }

        if (!buffer->data) {
                int fd = perf_data__fd(btsq->bts->session->data);

                buffer->data = auxtrace_buffer__get_data(buffer, fd);
                if (!buffer->data) {
                        err = -ENOMEM;
                        goto out_put;
                }
        }

        if (btsq->bts->snapshot_mode && !buffer->consecutive &&
            intel_bts_do_fix_overlap(queue, buffer)) {
                err = -ENOMEM;
                goto out_put;
        }

        if (!btsq->bts->synth_opts.callchain &&
            !btsq->bts->synth_opts.thread_stack && thread &&
            (!old_buffer || btsq->bts->sampling_mode ||
             (btsq->bts->snapshot_mode && !buffer->consecutive)))
                thread_stack__set_trace_nr(thread, btsq->cpu, buffer->buffer_nr + 1);

        err = intel_bts_process_buffer(btsq, buffer, thread);

        auxtrace_buffer__drop_data(buffer);

        btsq->buffer = auxtrace_buffer__next(queue, buffer);
        if (btsq->buffer) {
                if (timestamp)
                        *timestamp = btsq->buffer->reference;
        } else {
                if (!btsq->bts->sampling_mode)
                        btsq->done = 1;
        }
out_put:
        thread__put(thread);
        return err;
}

static int intel_bts_flush_queue(struct intel_bts_queue *btsq)
{
        u64 ts = 0;
        int ret;

        while (1) {
                ret = intel_bts_process_queue(btsq, &ts);
                if (ret < 0)
                        return ret;
                if (ret)
                        break;
        }
        return 0;
}

static int intel_bts_process_tid_exit(struct intel_bts *bts, pid_t tid)
{
        struct auxtrace_queues *queues = &bts->queues;
        unsigned int i;

        for (i = 0; i < queues->nr_queues; i++) {
                struct auxtrace_queue *queue = &bts->queues.queue_array[i];
                struct intel_bts_queue *btsq = queue->priv;

                if (btsq && btsq->tid == tid)
                        return intel_bts_flush_queue(btsq);
        }
        return 0;
}

static int intel_bts_process_queues(struct intel_bts *bts, u64 timestamp)
{
        while (1) {
                unsigned int queue_nr;
                struct auxtrace_queue *queue;
                struct intel_bts_queue *btsq;
                u64 ts = 0;
                int ret;

                if (!bts->heap.heap_cnt)
                        return 0;

                if (bts->heap.heap_array[0].ordinal > timestamp)
                        return 0;

                queue_nr = bts->heap.heap_array[0].queue_nr;
                queue = &bts->queues.queue_array[queue_nr];
                btsq = queue->priv;

                auxtrace_heap__pop(&bts->heap);

                ret = intel_bts_process_queue(btsq, &ts);
                if (ret < 0) {
                        auxtrace_heap__add(&bts->heap, queue_nr, ts);
                        return ret;
                }

                if (!ret) {
                        ret = auxtrace_heap__add(&bts->heap, queue_nr, ts);
                        if (ret < 0)
                                return ret;
                } else {
                        btsq->on_heap = false;
                }
        }

        return 0;
}

static int intel_bts_process_event(struct perf_session *session,
                                   union perf_event *event,
                                   struct perf_sample *sample,
                                   const struct perf_tool *tool)
{
        struct intel_bts *bts = container_of(session->auxtrace, struct intel_bts,
                                             auxtrace);
        u64 timestamp;
        int err;

        if (dump_trace)
                return 0;

        if (!tool->ordered_events) {
                pr_err("Intel BTS requires ordered events\n");
                return -EINVAL;
        }

        if (sample->time && sample->time != (u64)-1)
                timestamp = perf_time_to_tsc(sample->time, &bts->tc);
        else
                timestamp = 0;

        err = intel_bts_update_queues(bts);
        if (err)
                return err;

        err = intel_bts_process_queues(bts, timestamp);
        if (err)
                return err;
        if (event->header.type == PERF_RECORD_EXIT) {
                err = intel_bts_process_tid_exit(bts, event->fork.tid);
                if (err)
                        return err;
        }

        if (event->header.type == PERF_RECORD_AUX &&
            (event->aux.flags & PERF_AUX_FLAG_TRUNCATED) &&
            bts->synth_opts.errors)
                err = intel_bts_lost(bts, sample);

        return err;
}

static int intel_bts_process_auxtrace_event(struct perf_session *session,
                                            union perf_event *event,
                                            const struct perf_tool *tool __maybe_unused)
{
        struct intel_bts *bts = container_of(session->auxtrace, struct intel_bts,
                                             auxtrace);

        if (bts->sampling_mode)
                return 0;

        if (!bts->data_queued) {
                struct auxtrace_buffer *buffer;
                off_t data_offset;
                int fd = perf_data__fd(session->data);
                int err;

                if (perf_data__is_pipe(session->data)) {
                        data_offset = 0;
                } else {
                        data_offset = lseek(fd, 0, SEEK_CUR);
                        if (data_offset == -1)
                                return -errno;
                }

                err = auxtrace_queues__add_event(&bts->queues, session, event,
                                                 data_offset, &buffer);
                if (err)
                        return err;

                /* Dump here now we have copied a piped trace out of the pipe */
                if (dump_trace) {
                        if (auxtrace_buffer__get_data(buffer, fd)) {
                                intel_bts_dump_event(bts, buffer->data,
                                                     buffer->size);
                                auxtrace_buffer__put_data(buffer);
                        }
                }
        }

        return 0;
}

static int intel_bts_flush(struct perf_session *session,
                           const struct perf_tool *tool __maybe_unused)
{
        struct intel_bts *bts = container_of(session->auxtrace, struct intel_bts,
                                             auxtrace);
        int ret;

        if (dump_trace || bts->sampling_mode)
                return 0;

        if (!tool->ordered_events)
                return -EINVAL;

        ret = intel_bts_update_queues(bts);
        if (ret < 0)
                return ret;

        return intel_bts_process_queues(bts, MAX_TIMESTAMP);
}

static void intel_bts_free_queue(void *priv)
{
        struct intel_bts_queue *btsq = priv;

        if (!btsq)
                return;
        free(btsq);
}

static void intel_bts_free_events(struct perf_session *session)
{
        struct intel_bts *bts = container_of(session->auxtrace, struct intel_bts,
                                             auxtrace);
        struct auxtrace_queues *queues = &bts->queues;
        unsigned int i;

        for (i = 0; i < queues->nr_queues; i++) {
                intel_bts_free_queue(queues->queue_array[i].priv);
                queues->queue_array[i].priv = NULL;
        }
        auxtrace_queues__free(queues);
}

static void intel_bts_free(struct perf_session *session)
{
        struct intel_bts *bts = container_of(session->auxtrace, struct intel_bts,
                                             auxtrace);

        auxtrace_heap__free(&bts->heap);
        intel_bts_free_events(session);
        session->auxtrace = NULL;
        free(bts);
}

static bool intel_bts_evsel_is_auxtrace(struct perf_session *session,
                                        struct evsel *evsel)
{
        struct intel_bts *bts = container_of(session->auxtrace, struct intel_bts,
                                             auxtrace);

        return evsel->core.attr.type == bts->pmu_type;
}

static int intel_bts_synth_events(struct intel_bts *bts,
                                  struct perf_session *session)
{
        struct evlist *evlist = session->evlist;
        struct evsel *evsel;
        struct perf_event_attr attr;
        bool found = false;
        u64 id;
        int err;

        evlist__for_each_entry(evlist, evsel) {
                if (evsel->core.attr.type == bts->pmu_type && evsel->core.ids) {
                        found = true;
                        break;
                }
        }

        if (!found) {
                pr_debug("There are no selected events with Intel BTS data\n");
                return 0;
        }

        memset(&attr, 0, sizeof(struct perf_event_attr));
        attr.size = sizeof(struct perf_event_attr);
        attr.type = PERF_TYPE_HARDWARE;
        attr.sample_type = evsel->core.attr.sample_type & PERF_SAMPLE_MASK;
        attr.sample_type |= PERF_SAMPLE_IP | PERF_SAMPLE_TID |
                            PERF_SAMPLE_PERIOD;
        attr.sample_type &= ~(u64)PERF_SAMPLE_TIME;
        attr.sample_type &= ~(u64)PERF_SAMPLE_CPU;
        attr.exclude_user = evsel->core.attr.exclude_user;
        attr.exclude_kernel = evsel->core.attr.exclude_kernel;
        attr.exclude_hv = evsel->core.attr.exclude_hv;
        attr.exclude_host = evsel->core.attr.exclude_host;
        attr.exclude_guest = evsel->core.attr.exclude_guest;
        attr.sample_id_all = evsel->core.attr.sample_id_all;
        attr.read_format = evsel->core.attr.read_format;

        id = auxtrace_synth_id_range_start(evsel);

        if (bts->synth_opts.branches) {
                attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS;
                attr.sample_period = 1;
                attr.sample_type |= PERF_SAMPLE_ADDR;
                pr_debug("Synthesizing 'branches' event with id %" PRIu64 " sample type %#" PRIx64 "\n",
                         id, (u64)attr.sample_type);
                err = perf_session__deliver_synth_attr_event(session, &attr, id);
                if (err) {
                        pr_err("%s: failed to synthesize 'branches' event type\n",
                               __func__);
                        return err;
                }
                bts->sample_branches = true;
                bts->branches_sample_type = attr.sample_type;
                bts->branches_id = id;
                /*
                 * We only use sample types from PERF_SAMPLE_MASK so we can use
                 * __evsel__sample_size() here.
                 */
                bts->branches_event_size = sizeof(struct perf_record_sample) +
                                           __evsel__sample_size(attr.sample_type);
        }

        return 0;
}

static const char * const intel_bts_info_fmts[] = {
        [INTEL_BTS_PMU_TYPE]            = "  PMU Type           %"PRId64"\n",
        [INTEL_BTS_TIME_SHIFT]          = "  Time Shift         %"PRIu64"\n",
        [INTEL_BTS_TIME_MULT]           = "  Time Multiplier    %"PRIu64"\n",
        [INTEL_BTS_TIME_ZERO]           = "  Time Zero          %"PRIu64"\n",
        [INTEL_BTS_CAP_USER_TIME_ZERO]  = "  Cap Time Zero      %"PRId64"\n",
        [INTEL_BTS_SNAPSHOT_MODE]       = "  Snapshot mode      %"PRId64"\n",
};

static void intel_bts_print_info(__u64 *arr, int start, int finish)
{
        int i;

        if (!dump_trace)
                return;

        for (i = start; i <= finish; i++)
                fprintf(stdout, intel_bts_info_fmts[i], arr[i]);
}

int intel_bts_process_auxtrace_info(union perf_event *event,
                                    struct perf_session *session)
{
        struct perf_record_auxtrace_info *auxtrace_info = &event->auxtrace_info;
        size_t min_sz = sizeof(u64) * INTEL_BTS_SNAPSHOT_MODE;
        struct intel_bts *bts;
        int err;

        if (auxtrace_info->header.size < sizeof(struct perf_record_auxtrace_info) +
                                        min_sz)
                return -EINVAL;

        bts = zalloc(sizeof(struct intel_bts));
        if (!bts)
                return -ENOMEM;

        err = auxtrace_queues__init(&bts->queues);
        if (err)
                goto err_free;

        bts->session = session;
        bts->machine = &session->machines.host; /* No kvm support */
        bts->auxtrace_type = auxtrace_info->type;
        bts->pmu_type = auxtrace_info->priv[INTEL_BTS_PMU_TYPE];
        bts->tc.time_shift = auxtrace_info->priv[INTEL_BTS_TIME_SHIFT];
        bts->tc.time_mult = auxtrace_info->priv[INTEL_BTS_TIME_MULT];
        bts->tc.time_zero = auxtrace_info->priv[INTEL_BTS_TIME_ZERO];
        bts->cap_user_time_zero =
                        auxtrace_info->priv[INTEL_BTS_CAP_USER_TIME_ZERO];
        bts->snapshot_mode = auxtrace_info->priv[INTEL_BTS_SNAPSHOT_MODE];

        bts->sampling_mode = false;

        bts->auxtrace.process_event = intel_bts_process_event;
        bts->auxtrace.process_auxtrace_event = intel_bts_process_auxtrace_event;
        bts->auxtrace.flush_events = intel_bts_flush;
        bts->auxtrace.free_events = intel_bts_free_events;
        bts->auxtrace.free = intel_bts_free;
        bts->auxtrace.evsel_is_auxtrace = intel_bts_evsel_is_auxtrace;
        session->auxtrace = &bts->auxtrace;

        intel_bts_print_info(&auxtrace_info->priv[0], INTEL_BTS_PMU_TYPE,
                             INTEL_BTS_SNAPSHOT_MODE);

        if (dump_trace)
                return 0;

        if (session->itrace_synth_opts->set) {
                bts->synth_opts = *session->itrace_synth_opts;
        } else {
                itrace_synth_opts__set_default(&bts->synth_opts,
                                session->itrace_synth_opts->default_no_sample);
                bts->synth_opts.thread_stack =
                                session->itrace_synth_opts->thread_stack;
        }

        if (bts->synth_opts.calls)
                bts->branches_filter |= PERF_IP_FLAG_CALL | PERF_IP_FLAG_ASYNC |
                                        PERF_IP_FLAG_TRACE_END;
        if (bts->synth_opts.returns)
                bts->branches_filter |= PERF_IP_FLAG_RETURN |
                                        PERF_IP_FLAG_TRACE_BEGIN;

        err = intel_bts_synth_events(bts, session);
        if (err)
                goto err_free_queues;

        err = auxtrace_queues__process_index(&bts->queues, session);
        if (err)
                goto err_free_queues;

        if (bts->queues.populated)
                bts->data_queued = true;

        return 0;

err_free_queues:
        auxtrace_queues__free(&bts->queues);
        session->auxtrace = NULL;
err_free:
        free(bts);
        return err;
}