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 30 int trace_events_enabled_count; 31 /* 32 * Interpretation depends on wether the event has the 'vcpu' property: 33 * - false: Boolean value indicating whether the event is active. 34 * - true : Integral counting the number of vCPUs that have this event enabled. 35 */ 36 uint16_t trace_events_dstate[TRACE_EVENT_COUNT]; 37 /* Marks events for late vCPU state init */ 38 static bool trace_events_dstate_init[TRACE_EVENT_COUNT]; 39 40 QemuOptsList qemu_trace_opts = { 41 .name = "trace", 42 .implied_opt_name = "enable", 43 .head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head), 44 .desc = { 45 { 46 .name = "enable", 47 .type = QEMU_OPT_STRING, 48 }, 49 { 50 .name = "events", 51 .type = QEMU_OPT_STRING, 52 },{ 53 .name = "file", 54 .type = QEMU_OPT_STRING, 55 }, 56 { /* end of list */ } 57 }, 58 }; 59 60 61 TraceEvent *trace_event_name(const char *name) 62 { 63 assert(name != NULL); 64 65 TraceEventID i; 66 for (i = 0; i < trace_event_count(); i++) { 67 TraceEvent *ev = trace_event_id(i); 68 if (strcmp(trace_event_get_name(ev), name) == 0) { 69 return ev; 70 } 71 } 72 return NULL; 73 } 74 75 static bool pattern_glob(const char *pat, const char *ev) 76 { 77 while (*pat != '\0' && *ev != '\0') { 78 if (*pat == *ev) { 79 pat++; 80 ev++; 81 } 82 else if (*pat == '*') { 83 if (pattern_glob(pat, ev+1)) { 84 return true; 85 } else if (pattern_glob(pat+1, ev)) { 86 return true; 87 } else { 88 return false; 89 } 90 } else { 91 return false; 92 } 93 } 94 95 while (*pat == '*') { 96 pat++; 97 } 98 99 if (*pat == '\0' && *ev == '\0') { 100 return true; 101 } else { 102 return false; 103 } 104 } 105 106 TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev) 107 { 108 assert(pat != NULL); 109 110 TraceEventID i; 111 112 if (ev == NULL) { 113 i = -1; 114 } else { 115 i = trace_event_get_id(ev); 116 } 117 i++; 118 119 while (i < trace_event_count()) { 120 TraceEvent *res = trace_event_id(i); 121 if (pattern_glob(pat, trace_event_get_name(res))) { 122 return res; 123 } 124 i++; 125 } 126 127 return NULL; 128 } 129 130 void trace_list_events(void) 131 { 132 int i; 133 for (i = 0; i < trace_event_count(); i++) { 134 TraceEvent *res = trace_event_id(i); 135 fprintf(stderr, "%s\n", trace_event_get_name(res)); 136 } 137 } 138 139 static void do_trace_enable_events(const char *line_buf) 140 { 141 const bool enable = ('-' != line_buf[0]); 142 const char *line_ptr = enable ? line_buf : line_buf + 1; 143 144 if (trace_event_is_pattern(line_ptr)) { 145 TraceEvent *ev = NULL; 146 while ((ev = trace_event_pattern(line_ptr, ev)) != NULL) { 147 if (trace_event_get_state_static(ev)) { 148 /* start tracing */ 149 trace_event_set_state_dynamic(ev, enable); 150 /* mark for late vCPU init */ 151 trace_events_dstate_init[ev->id] = true; 152 } 153 } 154 } else { 155 TraceEvent *ev = trace_event_name(line_ptr); 156 if (ev == NULL) { 157 error_report("WARNING: trace event '%s' does not exist", 158 line_ptr); 159 } else if (!trace_event_get_state_static(ev)) { 160 error_report("WARNING: trace event '%s' is not traceable", 161 line_ptr); 162 } else { 163 /* start tracing */ 164 trace_event_set_state_dynamic(ev, enable); 165 /* mark for late vCPU init */ 166 trace_events_dstate_init[ev->id] = true; 167 } 168 } 169 } 170 171 void trace_enable_events(const char *line_buf) 172 { 173 if (is_help_option(line_buf)) { 174 trace_list_events(); 175 if (cur_mon == NULL) { 176 exit(0); 177 } 178 } else { 179 do_trace_enable_events(line_buf); 180 } 181 } 182 183 static void trace_init_events(const char *fname) 184 { 185 Location loc; 186 FILE *fp; 187 char line_buf[1024]; 188 size_t line_idx = 0; 189 190 if (fname == NULL) { 191 return; 192 } 193 194 loc_push_none(&loc); 195 loc_set_file(fname, 0); 196 fp = fopen(fname, "r"); 197 if (!fp) { 198 error_report("%s", strerror(errno)); 199 exit(1); 200 } 201 while (fgets(line_buf, sizeof(line_buf), fp)) { 202 loc_set_file(fname, ++line_idx); 203 size_t len = strlen(line_buf); 204 if (len > 1) { /* skip empty lines */ 205 line_buf[len - 1] = '\0'; 206 if ('#' == line_buf[0]) { /* skip commented lines */ 207 continue; 208 } 209 trace_enable_events(line_buf); 210 } 211 } 212 if (fclose(fp) != 0) { 213 loc_set_file(fname, 0); 214 error_report("%s", strerror(errno)); 215 exit(1); 216 } 217 loc_pop(&loc); 218 } 219 220 void trace_init_file(const char *file) 221 { 222 #ifdef CONFIG_TRACE_SIMPLE 223 st_set_trace_file(file); 224 #elif defined CONFIG_TRACE_LOG 225 /* If both the simple and the log backends are enabled, "-trace file" 226 * only applies to the simple backend; use "-D" for the log backend. 227 */ 228 if (file) { 229 qemu_set_log_filename(file, &error_fatal); 230 } 231 #else 232 if (file) { 233 fprintf(stderr, "error: -trace file=...: " 234 "option not supported by the selected tracing backends\n"); 235 exit(1); 236 } 237 #endif 238 } 239 240 bool trace_init_backends(void) 241 { 242 #ifdef CONFIG_TRACE_SIMPLE 243 if (!st_init()) { 244 fprintf(stderr, "failed to initialize simple tracing backend.\n"); 245 return false; 246 } 247 #endif 248 249 #ifdef CONFIG_TRACE_FTRACE 250 if (!ftrace_init()) { 251 fprintf(stderr, "failed to initialize ftrace backend.\n"); 252 return false; 253 } 254 #endif 255 256 #ifdef CONFIG_TRACE_SYSLOG 257 openlog(NULL, LOG_PID, LOG_DAEMON); 258 #endif 259 260 return true; 261 } 262 263 char *trace_opt_parse(const char *optarg) 264 { 265 char *trace_file; 266 QemuOpts *opts = qemu_opts_parse_noisily(qemu_find_opts("trace"), 267 optarg, true); 268 if (!opts) { 269 exit(1); 270 } 271 if (qemu_opt_get(opts, "enable")) { 272 trace_enable_events(qemu_opt_get(opts, "enable")); 273 } 274 trace_init_events(qemu_opt_get(opts, "events")); 275 trace_file = g_strdup(qemu_opt_get(opts, "file")); 276 qemu_opts_del(opts); 277 278 return trace_file; 279 } 280 281 void trace_init_vcpu_events(void) 282 { 283 TraceEvent *ev = NULL; 284 while ((ev = trace_event_pattern("*", ev)) != NULL) { 285 if (trace_event_is_vcpu(ev) && 286 trace_event_get_state_static(ev) && 287 trace_events_dstate_init[ev->id]) { 288 trace_event_set_state_dynamic(ev, true); 289 } 290 } 291 } 292