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