LXR qemu/trace/qmp.c

   1/*
   2 * QMP commands for tracing events.
   3 *
   4 * Copyright (C) 2014-2016 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 "qmp-commands.h"
  12#include "trace/control.h"
  13
  14
  15static CPUState *get_cpu(bool has_vcpu, int vcpu, Error **errp)
  16{
  17    if (has_vcpu) {
  18        CPUState *cpu = qemu_get_cpu(vcpu);
  19        if (cpu == NULL) {
  20            error_setg(errp, "invalid vCPU index %u", vcpu);
  21        }
  22        return cpu;
  23    } else {
  24        return NULL;
  25    }
  26}
  27
  28static bool check_events(bool has_vcpu, bool ignore_unavailable, bool is_pattern,
  29                         const char *name, Error **errp)
  30{
  31    if (!is_pattern) {
  32        TraceEvent *ev = trace_event_name(name);
  33
  34        /* error for non-existing event */
  35        if (ev == NULL) {
  36            error_setg(errp, "unknown event \"%s\"", name);
  37            return false;
  38        }
  39
  40        /* error for non-vcpu event */
  41        if (has_vcpu && !trace_event_is_vcpu(ev)) {
  42            error_setg(errp, "event \"%s\" is not vCPU-specific", name);
  43            return false;
  44        }
  45
  46        /* error for unavailable event */
  47        if (!ignore_unavailable && !trace_event_get_state_static(ev)) {
  48            error_setg(errp, "event \"%s\" is disabled", name);
  49            return false;
  50        }
  51
  52        return true;
  53    } else {
  54        /* error for unavailable events */
  55        TraceEvent *ev = NULL;
  56        while ((ev = trace_event_pattern(name, ev)) != NULL) {
  57            if (!ignore_unavailable && !trace_event_get_state_static(ev)) {
  58                error_setg(errp, "event \"%s\" is disabled", trace_event_get_name(ev));
  59                return false;
  60            }
  61        }
  62        return true;
  63    }
  64}
  65
  66TraceEventInfoList *qmp_trace_event_get_state(const char *name,
  67                                              bool has_vcpu, int64_t vcpu,
  68                                              Error **errp)
  69{
  70    Error *err = NULL;
  71    TraceEventInfoList *events = NULL;
  72    TraceEvent *ev;
  73    bool is_pattern = trace_event_is_pattern(name);
  74    CPUState *cpu;
  75
  76    /* Check provided vcpu */
  77    cpu = get_cpu(has_vcpu, vcpu, &err);
  78    if (err) {
  79        error_propagate(errp, err);
  80        return NULL;
  81    }
  82
  83    /* Check events */
  84    if (!check_events(has_vcpu, true, is_pattern, name, errp)) {
  85        return NULL;
  86    }
  87
  88    /* Get states (all errors checked above) */
  89    ev = NULL;
  90    while ((ev = trace_event_pattern(name, ev)) != NULL) {
  91        TraceEventInfoList *elem;
  92        bool is_vcpu = trace_event_is_vcpu(ev);
  93        if (has_vcpu && !is_vcpu) {
  94            continue;
  95        }
  96
  97        elem = g_new(TraceEventInfoList, 1);
  98        elem->value = g_new(TraceEventInfo, 1);
  99        elem->value->vcpu = is_vcpu;
 100        elem->value->name = g_strdup(trace_event_get_name(ev));
 101
 102        if (!trace_event_get_state_static(ev)) {
 103            elem->value->state = TRACE_EVENT_STATE_UNAVAILABLE;
 104        } else {
 105            if (has_vcpu) {
 106                if (is_vcpu) {
 107                    if (trace_event_get_vcpu_state_dynamic(cpu, ev)) {
 108                        elem->value->state = TRACE_EVENT_STATE_ENABLED;
 109                    } else {
 110                        elem->value->state = TRACE_EVENT_STATE_DISABLED;
 111                    }
 112                }
 113                /* else: already skipped above */
 114            } else {
 115                if (trace_event_get_state_dynamic(ev)) {
 116                    elem->value->state = TRACE_EVENT_STATE_ENABLED;
 117                } else {
 118                    elem->value->state = TRACE_EVENT_STATE_DISABLED;
 119                }
 120            }
 121        }
 122        elem->next = events;
 123        events = elem;
 124    }
 125
 126    return events;
 127}
 128
 129void qmp_trace_event_set_state(const char *name, bool enable,
 130                               bool has_ignore_unavailable, bool ignore_unavailable,
 131                               bool has_vcpu, int64_t vcpu,
 132                               Error **errp)
 133{
 134    Error *err = NULL;
 135    TraceEvent *ev;
 136    bool is_pattern = trace_event_is_pattern(name);
 137    CPUState *cpu;
 138
 139    /* Check provided vcpu */
 140    cpu = get_cpu(has_vcpu, vcpu, &err);
 141    if (err) {
 142        error_propagate(errp, err);
 143        return;
 144    }
 145
 146    /* Check events */
 147    if (!check_events(has_vcpu, has_ignore_unavailable && ignore_unavailable,
 148                      is_pattern, name, errp)) {
 149        return;
 150    }
 151
 152    /* Apply changes (all errors checked above) */
 153    ev = NULL;
 154    while ((ev = trace_event_pattern(name, ev)) != NULL) {
 155        if (!trace_event_get_state_static(ev) ||
 156            (has_vcpu && !trace_event_is_vcpu(ev))) {
 157            continue;
 158        }
 159        if (has_vcpu) {
 160            trace_event_set_vcpu_state_dynamic(cpu, ev, enable);
 161        } else {
 162            trace_event_set_state_dynamic(ev, enable);
 163        }
 164    }
 165}
 166