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 "qapi/error.h"
  12 #include "qapi/qapi-commands-trace.h"
  13 #include "control.h"
  14
  15
  16 static CPUState *get_cpu(bool has_vcpu, int vcpu, Error **errp)
  17 {
  18     if (has_vcpu) {
  19         CPUState *cpu = qemu_get_cpu(vcpu);
  20         if (cpu == NULL) {
  21             error_setg(errp, "invalid vCPU index %u", vcpu);
  22         }
  23         return cpu;
  24     } else {
  25         return NULL;
  26     }
  27 }
  28
  29 static bool check_events(bool has_vcpu, bool ignore_unavailable, bool is_pattern,
  30                          const char *name, Error **errp)
  31 {
  32     if (!is_pattern) {
  33         TraceEvent *ev = trace_event_name(name);
  34
  35         /* error for non-existing event */
  36         if (ev == NULL) {
  37             error_setg(errp, "unknown event \"%s\"", name);
  38             return false;
  39         }
  40
  41         /* error for non-vcpu event */
  42         if (has_vcpu && !trace_event_is_vcpu(ev)) {
  43             error_setg(errp, "event \"%s\" is not vCPU-specific", name);
  44             return false;
  45         }
  46
  47         /* error for unavailable event */
  48         if (!ignore_unavailable && !trace_event_get_state_static(ev)) {
  49             error_setg(errp, "event \"%s\" is disabled", name);
  50             return false;
  51         }
  52
  53         return true;
  54     } else {
  55         /* error for unavailable events */
  56         TraceEventIter iter;
  57         TraceEvent *ev;
  58         trace_event_iter_init(&iter, name);
  59         while ((ev = trace_event_iter_next(&iter)) != NULL) {
  60             if (!ignore_unavailable && !trace_event_get_state_static(ev)) {
  61                 error_setg(errp, "event \"%s\" is disabled", trace_event_get_name(ev));
  62                 return false;
  63             }
  64         }
  65         return true;
  66     }
  67 }
  68
  69 TraceEventInfoList *qmp_trace_event_get_state(const char *name,
  70                                               bool has_vcpu, int64_t vcpu,
  71                                               Error **errp)
  72 {
  73     Error *err = NULL;
  74     TraceEventInfoList *events = NULL;
  75     TraceEventIter iter;
  76     TraceEvent *ev;
  77     bool is_pattern = trace_event_is_pattern(name);
  78     CPUState *cpu;
  79
  80     /* Check provided vcpu */
  81     cpu = get_cpu(has_vcpu, vcpu, &err);
  82     if (err) {
  83         error_propagate(errp, err);
  84         return NULL;
  85     }
  86
  87     /* Check events */
  88     if (!check_events(has_vcpu, true, is_pattern, name, errp)) {
  89         return NULL;
  90     }
  91
  92     /* Get states (all errors checked above) */
  93     trace_event_iter_init(&iter, name);
  94     while ((ev = trace_event_iter_next(&iter)) != NULL) {
  95         TraceEventInfoList *elem;
  96         bool is_vcpu = trace_event_is_vcpu(ev);
  97         if (has_vcpu && !is_vcpu) {
  98             continue;
  99         }
 100
 101         elem = g_new(TraceEventInfoList, 1);
 102         elem->value = g_new(TraceEventInfo, 1);
 103         elem->value->vcpu = is_vcpu;
 104         elem->value->name = g_strdup(trace_event_get_name(ev));
 105
 106         if (!trace_event_get_state_static(ev)) {
 107             elem->value->state = TRACE_EVENT_STATE_UNAVAILABLE;
 108         } else {
 109             if (has_vcpu) {
 110                 if (is_vcpu) {
 111                     if (trace_event_get_vcpu_state_dynamic(cpu, ev)) {
 112                         elem->value->state = TRACE_EVENT_STATE_ENABLED;
 113                     } else {
 114                         elem->value->state = TRACE_EVENT_STATE_DISABLED;
 115                     }
 116                 }
 117                 /* else: already skipped above */
 118             } else {
 119                 if (trace_event_get_state_dynamic(ev)) {
 120                     elem->value->state = TRACE_EVENT_STATE_ENABLED;
 121                 } else {
 122                     elem->value->state = TRACE_EVENT_STATE_DISABLED;
 123                 }
 124             }
 125         }
 126         elem->next = events;
 127         events = elem;
 128     }
 129
 130     return events;
 131 }
 132
 133 void qmp_trace_event_set_state(const char *name, bool enable,
 134                                bool has_ignore_unavailable, bool ignore_unavailable,
 135                                bool has_vcpu, int64_t vcpu,
 136                                Error **errp)
 137 {
 138     Error *err = NULL;
 139     TraceEventIter iter;
 140     TraceEvent *ev;
 141     bool is_pattern = trace_event_is_pattern(name);
 142     CPUState *cpu;
 143
 144     /* Check provided vcpu */
 145     cpu = get_cpu(has_vcpu, vcpu, &err);
 146     if (err) {
 147         error_propagate(errp, err);
 148         return;
 149     }
 150
 151     /* Check events */
 152     if (!check_events(has_vcpu, has_ignore_unavailable && ignore_unavailable,
 153                       is_pattern, name, errp)) {
 154         return;
 155     }
 156
 157     /* Apply changes (all errors checked above) */
 158     trace_event_iter_init(&iter, name);
 159     while ((ev = trace_event_iter_next(&iter)) != NULL) {
 160         if (!trace_event_get_state_static(ev) ||
 161             (has_vcpu && !trace_event_is_vcpu(ev))) {
 162             continue;
 163         }
 164         if (has_vcpu) {
 165             trace_event_set_vcpu_state_dynamic(cpu, ev, enable);
 166         } else {
 167             trace_event_set_state_dynamic(ev, enable);
 168         }
 169     }
 170 }