cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

control.c (8593B)

      1/*
      2 * Interface for configuring and controlling the state of tracing events.
      3 *
      4 * Copyright (C) 2011-2016 Lluís Vilanova <vilanova@ac.upc.edu>
      5 *
      6 * This work is licensed under the terms of the GNU GPL, version 2 or later.
      7 * See the COPYING file in the top-level directory.
      8 */
      9
     10#include "qemu/osdep.h"
     11#include "trace/control.h"
     12#include "qemu/help_option.h"
     13#include "qemu/option.h"
     14#ifdef CONFIG_TRACE_SIMPLE
     15#include "trace/simple.h"
     16#endif
     17#ifdef CONFIG_TRACE_FTRACE
     18#include "trace/ftrace.h"
     19#endif
     20#ifdef CONFIG_TRACE_LOG
     21#include "qemu/log.h"
     22#endif
     23#ifdef CONFIG_TRACE_SYSLOG
     24#include <syslog.h>
     25#endif
     26#include "qapi/error.h"
     27#include "qemu/error-report.h"
     28#include "qemu/config-file.h"
     29#include "monitor/monitor.h"
     30#include "trace/trace-root.h"
     31
     32int trace_events_enabled_count;
     33
     34typedef struct TraceEventGroup {
     35    TraceEvent **events;
     36} TraceEventGroup;
     37
     38static TraceEventGroup *event_groups;
     39static size_t nevent_groups;
     40static uint32_t next_id;
     41static uint32_t next_vcpu_id;
     42static bool init_trace_on_startup;
     43static char *trace_opts_file;
     44
     45QemuOptsList qemu_trace_opts = {
     46    .name = "trace",
     47    .implied_opt_name = "enable",
     48    .head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head),
     49    .desc = {
     50        {
     51            .name = "enable",
     52            .type = QEMU_OPT_STRING,
     53        },
     54        {
     55            .name = "events",
     56            .type = QEMU_OPT_STRING,
     57        },{
     58            .name = "file",
     59            .type = QEMU_OPT_STRING,
     60        },
     61        { /* end of list */ }
     62    },
     63};
     64
     65
     66void trace_event_register_group(TraceEvent **events)
     67{
     68    size_t i;
     69    for (i = 0; events[i] != NULL; i++) {
     70        events[i]->id = next_id++;
     71        if (events[i]->vcpu_id == TRACE_VCPU_EVENT_NONE) {
     72            continue;
     73        }
     74
     75        if (likely(next_vcpu_id < CPU_TRACE_DSTATE_MAX_EVENTS)) {
     76            events[i]->vcpu_id = next_vcpu_id++;
     77        } else {
     78            warn_report("too many vcpu trace events; dropping '%s'",
     79                        events[i]->name);
     80        }
     81    }
     82    event_groups = g_renew(TraceEventGroup, event_groups, nevent_groups + 1);
     83    event_groups[nevent_groups].events = events;
     84    nevent_groups++;
     85
     86#ifdef CONFIG_TRACE_SIMPLE
     87    st_init_group(nevent_groups - 1);
     88#endif
     89}
     90
     91
     92TraceEvent *trace_event_name(const char *name)
     93{
     94    assert(name != NULL);
     95
     96    TraceEventIter iter;
     97    TraceEvent *ev;
     98    trace_event_iter_init_all(&iter);
     99    while ((ev = trace_event_iter_next(&iter)) != NULL) {
    100        if (strcmp(trace_event_get_name(ev), name) == 0) {
    101            return ev;
    102        }
    103    }
    104    return NULL;
    105}
    106
    107void trace_event_iter_init_all(TraceEventIter *iter)
    108{
    109    iter->event = 0;
    110    iter->group = 0;
    111    iter->group_id = -1;
    112    iter->pattern = NULL;
    113}
    114
    115void trace_event_iter_init_pattern(TraceEventIter *iter, const char *pattern)
    116{
    117    trace_event_iter_init_all(iter);
    118    iter->pattern = pattern;
    119}
    120
    121void trace_event_iter_init_group(TraceEventIter *iter, size_t group_id)
    122{
    123    trace_event_iter_init_all(iter);
    124    iter->group_id = group_id;
    125}
    126
    127TraceEvent *trace_event_iter_next(TraceEventIter *iter)
    128{
    129    while (iter->group < nevent_groups &&
    130           event_groups[iter->group].events[iter->event] != NULL) {
    131        TraceEvent *ev = event_groups[iter->group].events[iter->event];
    132        size_t group = iter->group;
    133        iter->event++;
    134        if (event_groups[iter->group].events[iter->event] == NULL) {
    135            iter->event = 0;
    136            iter->group++;
    137        }
    138        if (iter->pattern &&
    139            !g_pattern_match_simple(iter->pattern, trace_event_get_name(ev))) {
    140            continue;
    141        }
    142        if (iter->group_id != -1 &&
    143            iter->group_id != group) {
    144            continue;
    145        }
    146        return ev;
    147    }
    148
    149    return NULL;
    150}
    151
    152void trace_list_events(FILE *f)
    153{
    154    TraceEventIter iter;
    155    TraceEvent *ev;
    156    trace_event_iter_init_all(&iter);
    157    while ((ev = trace_event_iter_next(&iter)) != NULL) {
    158        fprintf(f, "%s\n", trace_event_get_name(ev));
    159    }
    160#ifdef CONFIG_TRACE_DTRACE
    161    fprintf(f, "This list of names of trace points may be incomplete "
    162               "when using the DTrace/SystemTap backends.\n"
    163               "Run 'qemu-trace-stap list %s' to print the full list.\n",
    164            error_get_progname());
    165#endif
    166}
    167
    168static void do_trace_enable_events(const char *line_buf)
    169{
    170    const bool enable = ('-' != line_buf[0]);
    171    const char *line_ptr = enable ? line_buf : line_buf + 1;
    172    TraceEventIter iter;
    173    TraceEvent *ev;
    174    bool is_pattern = trace_event_is_pattern(line_ptr);
    175
    176    trace_event_iter_init_pattern(&iter, line_ptr);
    177    while ((ev = trace_event_iter_next(&iter)) != NULL) {
    178        if (!trace_event_get_state_static(ev)) {
    179            if (!is_pattern) {
    180                warn_report("trace event '%s' is not traceable",
    181                            line_ptr);
    182                return;
    183            }
    184            continue;
    185        }
    186
    187        /* start tracing */
    188        trace_event_set_state_dynamic(ev, enable);
    189        if (!is_pattern) {
    190            return;
    191        }
    192    }
    193
    194    if (!is_pattern) {
    195        warn_report("trace event '%s' does not exist",
    196                    line_ptr);
    197    }
    198}
    199
    200void trace_enable_events(const char *line_buf)
    201{
    202    if (is_help_option(line_buf)) {
    203        trace_list_events(stdout);
    204        if (monitor_cur() == NULL) {
    205            exit(0);
    206        }
    207    } else {
    208        do_trace_enable_events(line_buf);
    209    }
    210}
    211
    212static void trace_init_events(const char *fname)
    213{
    214    Location loc;
    215    FILE *fp;
    216    char line_buf[1024];
    217    size_t line_idx = 0;
    218
    219    if (fname == NULL) {
    220        return;
    221    }
    222
    223    loc_push_none(&loc);
    224    loc_set_file(fname, 0);
    225    fp = fopen(fname, "r");
    226    if (!fp) {
    227        error_report("%s", strerror(errno));
    228        exit(1);
    229    }
    230    while (fgets(line_buf, sizeof(line_buf), fp)) {
    231        loc_set_file(fname, ++line_idx);
    232        size_t len = strlen(line_buf);
    233        if (len > 1) {              /* skip empty lines */
    234            line_buf[len - 1] = '\0';
    235            if ('#' == line_buf[0]) { /* skip commented lines */
    236                continue;
    237            }
    238            trace_enable_events(line_buf);
    239        }
    240    }
    241    if (fclose(fp) != 0) {
    242        loc_set_file(fname, 0);
    243        error_report("%s", strerror(errno));
    244        exit(1);
    245    }
    246    loc_pop(&loc);
    247}
    248
    249void trace_init_file(void)
    250{
    251#ifdef CONFIG_TRACE_SIMPLE
    252    st_set_trace_file(trace_opts_file);
    253    if (init_trace_on_startup) {
    254        st_set_trace_file_enabled(true);
    255    }
    256#elif defined CONFIG_TRACE_LOG
    257    /*
    258     * If both the simple and the log backends are enabled, "--trace file"
    259     * only applies to the simple backend; use "-D" for the log
    260     * backend. However we should only override -D if we actually have
    261     * something to override it with.
    262     */
    263    if (trace_opts_file) {
    264        qemu_set_log_filename(trace_opts_file, &error_fatal);
    265    }
    266#else
    267    if (trace_opts_file) {
    268        fprintf(stderr, "error: --trace file=...: "
    269                "option not supported by the selected tracing backends\n");
    270        exit(1);
    271    }
    272#endif
    273}
    274
    275void trace_fini_vcpu(CPUState *vcpu)
    276{
    277    TraceEventIter iter;
    278    TraceEvent *ev;
    279
    280    trace_guest_cpu_exit(vcpu);
    281
    282    trace_event_iter_init_all(&iter);
    283    while ((ev = trace_event_iter_next(&iter)) != NULL) {
    284        if (trace_event_is_vcpu(ev) &&
    285            trace_event_get_state_static(ev) &&
    286            trace_event_get_vcpu_state_dynamic(vcpu, ev)) {
    287            /* must disable to affect the global counter */
    288            trace_event_set_vcpu_state_dynamic(vcpu, ev, false);
    289        }
    290    }
    291}
    292
    293bool trace_init_backends(void)
    294{
    295#ifdef CONFIG_TRACE_SIMPLE
    296    if (!st_init()) {
    297        fprintf(stderr, "failed to initialize simple tracing backend.\n");
    298        return false;
    299    }
    300#endif
    301
    302#ifdef CONFIG_TRACE_FTRACE
    303    if (!ftrace_init()) {
    304        fprintf(stderr, "failed to initialize ftrace backend.\n");
    305        return false;
    306    }
    307#endif
    308
    309#ifdef CONFIG_TRACE_SYSLOG
    310    openlog(NULL, LOG_PID, LOG_DAEMON);
    311#endif
    312
    313    return true;
    314}
    315
    316void trace_opt_parse(const char *optarg)
    317{
    318    QemuOpts *opts = qemu_opts_parse_noisily(qemu_find_opts("trace"),
    319                                             optarg, true);
    320    if (!opts) {
    321        exit(1);
    322    }
    323    if (qemu_opt_get(opts, "enable")) {
    324        trace_enable_events(qemu_opt_get(opts, "enable"));
    325    }
    326    trace_init_events(qemu_opt_get(opts, "events"));
    327    init_trace_on_startup = true;
    328    g_free(trace_opts_file);
    329    trace_opts_file = g_strdup(qemu_opt_get(opts, "file"));
    330    qemu_opts_del(opts);
    331}
    332
    333uint32_t trace_get_vcpu_event_count(void)
    334{
    335    return next_vcpu_id;
    336}