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 #ifndef TRACE__CONTROL_H 11 #define TRACE__CONTROL_H 12 13 #include "qemu-common.h" 14 #include "trace/generated-events.h" 15 16 17 /** 18 * TraceEventID: 19 * 20 * Unique tracing event identifier. 21 * 22 * These are named as 'TRACE_${EVENT_NAME}'. 23 * 24 * See also: "trace/generated-events.h" 25 */ 26 enum TraceEventID; 27 28 /** 29 * trace_event_id: 30 * @id: Event identifier. 31 * 32 * Get an event by its identifier. 33 * 34 * This routine has a constant cost, as opposed to trace_event_name and 35 * trace_event_pattern. 36 * 37 * Pre-conditions: The identifier is valid. 38 * 39 * Returns: pointer to #TraceEvent. 40 * 41 */ 42 static TraceEvent *trace_event_id(TraceEventID id); 43 44 /** 45 * trace_event_name: 46 * @id: Event name. 47 * 48 * Search an event by its name. 49 * 50 * Returns: pointer to #TraceEvent or NULL if not found. 51 */ 52 TraceEvent *trace_event_name(const char *name); 53 54 /** 55 * trace_event_pattern: 56 * @pat: Event name pattern. 57 * @ev: Event to start searching from (not included). 58 * 59 * Get all events with a given name pattern. 60 * 61 * Returns: pointer to #TraceEvent or NULL if not found. 62 */ 63 TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev); 64 65 /** 66 * trace_event_is_pattern: 67 * 68 * Whether the given string is an event name pattern. 69 */ 70 static bool trace_event_is_pattern(const char *str); 71 72 /** 73 * trace_event_count: 74 * 75 * Return the number of events. 76 */ 77 static TraceEventID trace_event_count(void); 78 79 80 81 /** 82 * trace_event_get_id: 83 * 84 * Get the identifier of an event. 85 */ 86 static TraceEventID trace_event_get_id(TraceEvent *ev); 87 88 /** 89 * trace_event_get_vcpu_id: 90 * 91 * Get the per-vCPU identifier of an event. 92 * 93 * Special value #TRACE_VCPU_EVENT_COUNT means the event is not vCPU-specific 94 * (does not have the "vcpu" property). 95 */ 96 static TraceEventVCPUID trace_event_get_vcpu_id(TraceEvent *ev); 97 98 /** 99 * trace_event_is_vcpu: 100 * 101 * Whether this is a per-vCPU event. 102 */ 103 static bool trace_event_is_vcpu(TraceEvent *ev); 104 105 /** 106 * trace_event_get_name: 107 * 108 * Get the name of an event. 109 */ 110 static const char * trace_event_get_name(TraceEvent *ev); 111 112 /** 113 * trace_event_get_state: 114 * @id: Event identifier. 115 * 116 * Get the tracing state of an event (both static and dynamic). 117 * 118 * If the event has the disabled property, the check will have no performance 119 * impact. 120 * 121 * As a down side, you must always use an immediate #TraceEventID value. 122 */ 123 #define trace_event_get_state(id) \ 124 ((id ##_ENABLED) && trace_event_get_state_dynamic_by_id(id)) 125 126 /** 127 * trace_event_get_state_static: 128 * @id: Event identifier. 129 * 130 * Get the static tracing state of an event. 131 * 132 * Use the define 'TRACE_${EVENT_NAME}_ENABLED' for compile-time checks (it will 133 * be set to 1 or 0 according to the presence of the disabled property). 134 */ 135 static bool trace_event_get_state_static(TraceEvent *ev); 136 137 /** 138 * trace_event_get_state_dynamic: 139 * 140 * Get the dynamic tracing state of an event. 141 */ 142 static bool trace_event_get_state_dynamic(TraceEvent *ev); 143 144 /** 145 * trace_event_set_state: 146 * 147 * Set the tracing state of an event (only if possible). 148 */ 149 #define trace_event_set_state(id, state) \ 150 do { \ 151 if ((id ##_ENABLED)) { \ 152 TraceEvent *_e = trace_event_id(id); \ 153 trace_event_set_state_dynamic(_e, state); \ 154 } \ 155 } while (0) 156 157 /** 158 * trace_event_set_state_dynamic: 159 * 160 * Set the dynamic tracing state of an event. 161 * 162 * Pre-condition: trace_event_get_state_static(ev) == true 163 */ 164 static void trace_event_set_state_dynamic(TraceEvent *ev, bool state); 165 166 167 168 /** 169 * trace_init_backends: 170 * @file: Name of trace output file; may be NULL. 171 * Corresponds to commandline option "-trace file=...". 172 * 173 * Initialize the tracing backend. 174 * 175 * Returns: Whether the backends could be successfully initialized. 176 */ 177 bool trace_init_backends(void); 178 179 /** 180 * trace_init_file: 181 * @file: Name of trace output file; may be NULL. 182 * Corresponds to commandline option "-trace file=...". 183 * 184 * Record the name of the output file for the tracing backend. 185 * Exits if no selected backend does not support specifying the 186 * output file, and a non-NULL file was passed. 187 */ 188 void trace_init_file(const char *file); 189 190 /** 191 * trace_list_events: 192 * 193 * List all available events. 194 */ 195 void trace_list_events(void); 196 197 /** 198 * trace_enable_events: 199 * @line_buf: A string with a glob pattern of events to be enabled or, 200 * if the string starts with '-', disabled. 201 * 202 * Enable or disable matching events. 203 */ 204 void trace_enable_events(const char *line_buf); 205 206 /** 207 * Definition of QEMU options describing trace subsystem configuration 208 */ 209 extern QemuOptsList qemu_trace_opts; 210 211 /** 212 * trace_opt_parse: 213 * @optarg: A string argument of --trace command line argument 214 * 215 * Initialize tracing subsystem. 216 * 217 * Returns the filename to save trace to. It must be freed with g_free(). 218 */ 219 char *trace_opt_parse(const char *optarg); 220 221 #include "trace/control-internal.h" 222 223 #endif /* TRACE__CONTROL_H */ 224