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
  15 static 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
  28 static 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
  66 TraceEventInfoList *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
 129 void 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 }