Merge tag 'seabios-20211203-pull-request' of git://git.kraxel.org/qemu into staging
[qemu.git] / trace / control.c
1 /*
2 * Interface for configuring and controlling the state of tracing events.
3 *
4 * Copyright (C) 2011-2016 LluĂ­s 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 #include "qemu/option.h"
14 #ifdef CONFIG_TRACE_SIMPLE
15 #include "trace/simple.h"
16 #endif
17 #ifdef CONFIG_TRACE_FTRACE
18 #include "trace/ftrace.h"
19 #endif
20 #ifdef CONFIG_TRACE_LOG
21 #include "qemu/log.h"
22 #endif
23 #ifdef CONFIG_TRACE_SYSLOG
24 #include <syslog.h>
25 #endif
26 #include "qapi/error.h"
27 #include "qemu/error-report.h"
28 #include "qemu/config-file.h"
29 #include "monitor/monitor.h"
30 #include "trace/trace-root.h"
31
32 int trace_events_enabled_count;
33
34 typedef struct TraceEventGroup {
35 TraceEvent **events;
36 } TraceEventGroup;
37
38 static TraceEventGroup *event_groups;
39 static size_t nevent_groups;
40 static uint32_t next_id;
41 static uint32_t next_vcpu_id;
42 static bool init_trace_on_startup;
43 static char *trace_opts_file;
44
45 QemuOptsList qemu_trace_opts = {
46 .name = "trace",
47 .implied_opt_name = "enable",
48 .head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head),
49 .desc = {
50 {
51 .name = "enable",
52 .type = QEMU_OPT_STRING,
53 },
54 {
55 .name = "events",
56 .type = QEMU_OPT_STRING,
57 },{
58 .name = "file",
59 .type = QEMU_OPT_STRING,
60 },
61 { /* end of list */ }
62 },
63 };
64
65
66 void trace_event_register_group(TraceEvent **events)
67 {
68 size_t i;
69 for (i = 0; events[i] != NULL; i++) {
70 events[i]->id = next_id++;
71 if (events[i]->vcpu_id == TRACE_VCPU_EVENT_NONE) {
72 continue;
73 }
74
75 if (likely(next_vcpu_id < CPU_TRACE_DSTATE_MAX_EVENTS)) {
76 events[i]->vcpu_id = next_vcpu_id++;
77 } else {
78 warn_report("too many vcpu trace events; dropping '%s'",
79 events[i]->name);
80 }
81 }
82 event_groups = g_renew(TraceEventGroup, event_groups, nevent_groups + 1);
83 event_groups[nevent_groups].events = events;
84 nevent_groups++;
85
86 #ifdef CONFIG_TRACE_SIMPLE
87 st_init_group(nevent_groups - 1);
88 #endif
89 }
90
91
92 TraceEvent *trace_event_name(const char *name)
93 {
94 assert(name != NULL);
95
96 TraceEventIter iter;
97 TraceEvent *ev;
98 trace_event_iter_init_all(&iter);
99 while ((ev = trace_event_iter_next(&iter)) != NULL) {
100 if (strcmp(trace_event_get_name(ev), name) == 0) {
101 return ev;
102 }
103 }
104 return NULL;
105 }
106
107 void trace_event_iter_init_all(TraceEventIter *iter)
108 {
109 iter->event = 0;
110 iter->group = 0;
111 iter->group_id = -1;
112 iter->pattern = NULL;
113 }
114
115 void trace_event_iter_init_pattern(TraceEventIter *iter, const char *pattern)
116 {
117 trace_event_iter_init_all(iter);
118 iter->pattern = pattern;
119 }
120
121 void trace_event_iter_init_group(TraceEventIter *iter, size_t group_id)
122 {
123 trace_event_iter_init_all(iter);
124 iter->group_id = group_id;
125 }
126
127 TraceEvent *trace_event_iter_next(TraceEventIter *iter)
128 {
129 while (iter->group < nevent_groups &&
130 event_groups[iter->group].events[iter->event] != NULL) {
131 TraceEvent *ev = event_groups[iter->group].events[iter->event];
132 size_t group = iter->group;
133 iter->event++;
134 if (event_groups[iter->group].events[iter->event] == NULL) {
135 iter->event = 0;
136 iter->group++;
137 }
138 if (iter->pattern &&
139 !g_pattern_match_simple(iter->pattern, trace_event_get_name(ev))) {
140 continue;
141 }
142 if (iter->group_id != -1 &&
143 iter->group_id != group) {
144 continue;
145 }
146 return ev;
147 }
148
149 return NULL;
150 }
151
152 void trace_list_events(FILE *f)
153 {
154 TraceEventIter iter;
155 TraceEvent *ev;
156 trace_event_iter_init_all(&iter);
157 while ((ev = trace_event_iter_next(&iter)) != NULL) {
158 fprintf(f, "%s\n", trace_event_get_name(ev));
159 }
160 #ifdef CONFIG_TRACE_DTRACE
161 fprintf(f, "This list of names of trace points may be incomplete "
162 "when using the DTrace/SystemTap backends.\n"
163 "Run 'qemu-trace-stap list %s' to print the full list.\n",
164 error_get_progname());
165 #endif
166 }
167
168 static void do_trace_enable_events(const char *line_buf)
169 {
170 const bool enable = ('-' != line_buf[0]);
171 const char *line_ptr = enable ? line_buf : line_buf + 1;
172 TraceEventIter iter;
173 TraceEvent *ev;
174 bool is_pattern = trace_event_is_pattern(line_ptr);
175
176 trace_event_iter_init_pattern(&iter, line_ptr);
177 while ((ev = trace_event_iter_next(&iter)) != NULL) {
178 if (!trace_event_get_state_static(ev)) {
179 if (!is_pattern) {
180 warn_report("trace event '%s' is not traceable",
181 line_ptr);
182 return;
183 }
184 continue;
185 }
186
187 /* start tracing */
188 trace_event_set_state_dynamic(ev, enable);
189 if (!is_pattern) {
190 return;
191 }
192 }
193
194 if (!is_pattern) {
195 warn_report("trace event '%s' does not exist",
196 line_ptr);
197 }
198 }
199
200 void trace_enable_events(const char *line_buf)
201 {
202 if (is_help_option(line_buf)) {
203 trace_list_events(stdout);
204 if (monitor_cur() == NULL) {
205 exit(0);
206 }
207 } else {
208 do_trace_enable_events(line_buf);
209 }
210 }
211
212 static void trace_init_events(const char *fname)
213 {
214 Location loc;
215 FILE *fp;
216 char line_buf[1024];
217 size_t line_idx = 0;
218
219 if (fname == NULL) {
220 return;
221 }
222
223 loc_push_none(&loc);
224 loc_set_file(fname, 0);
225 fp = fopen(fname, "r");
226 if (!fp) {
227 error_report("%s", strerror(errno));
228 exit(1);
229 }
230 while (fgets(line_buf, sizeof(line_buf), fp)) {
231 loc_set_file(fname, ++line_idx);
232 size_t len = strlen(line_buf);
233 if (len > 1) { /* skip empty lines */
234 line_buf[len - 1] = '\0';
235 if ('#' == line_buf[0]) { /* skip commented lines */
236 continue;
237 }
238 trace_enable_events(line_buf);
239 }
240 }
241 if (fclose(fp) != 0) {
242 loc_set_file(fname, 0);
243 error_report("%s", strerror(errno));
244 exit(1);
245 }
246 loc_pop(&loc);
247 }
248
249 void trace_init_file(void)
250 {
251 #ifdef CONFIG_TRACE_SIMPLE
252 st_set_trace_file(trace_opts_file);
253 if (init_trace_on_startup) {
254 st_set_trace_file_enabled(true);
255 }
256 #elif defined CONFIG_TRACE_LOG
257 /*
258 * If both the simple and the log backends are enabled, "--trace file"
259 * only applies to the simple backend; use "-D" for the log
260 * backend. However we should only override -D if we actually have
261 * something to override it with.
262 */
263 if (trace_opts_file) {
264 qemu_set_log_filename(trace_opts_file, &error_fatal);
265 }
266 #else
267 if (trace_opts_file) {
268 fprintf(stderr, "error: --trace file=...: "
269 "option not supported by the selected tracing backends\n");
270 exit(1);
271 }
272 #endif
273 }
274
275 void trace_fini_vcpu(CPUState *vcpu)
276 {
277 TraceEventIter iter;
278 TraceEvent *ev;
279
280 trace_guest_cpu_exit(vcpu);
281
282 trace_event_iter_init_all(&iter);
283 while ((ev = trace_event_iter_next(&iter)) != NULL) {
284 if (trace_event_is_vcpu(ev) &&
285 trace_event_get_state_static(ev) &&
286 trace_event_get_vcpu_state_dynamic(vcpu, ev)) {
287 /* must disable to affect the global counter */
288 trace_event_set_vcpu_state_dynamic(vcpu, ev, false);
289 }
290 }
291 }
292
293 bool trace_init_backends(void)
294 {
295 #ifdef CONFIG_TRACE_SIMPLE
296 if (!st_init()) {
297 fprintf(stderr, "failed to initialize simple tracing backend.\n");
298 return false;
299 }
300 #endif
301
302 #ifdef CONFIG_TRACE_FTRACE
303 if (!ftrace_init()) {
304 fprintf(stderr, "failed to initialize ftrace backend.\n");
305 return false;
306 }
307 #endif
308
309 #ifdef CONFIG_TRACE_SYSLOG
310 openlog(NULL, LOG_PID, LOG_DAEMON);
311 #endif
312
313 return true;
314 }
315
316 void trace_opt_parse(const char *optarg)
317 {
318 QemuOpts *opts = qemu_opts_parse_noisily(qemu_find_opts("trace"),
319 optarg, true);
320 if (!opts) {
321 exit(1);
322 }
323 if (qemu_opt_get(opts, "enable")) {
324 trace_enable_events(qemu_opt_get(opts, "enable"));
325 }
326 trace_init_events(qemu_opt_get(opts, "events"));
327 init_trace_on_startup = true;
328 g_free(trace_opts_file);
329 trace_opts_file = g_strdup(qemu_opt_get(opts, "file"));
330 qemu_opts_del(opts);
331 }
332
333 uint32_t trace_get_vcpu_event_count(void)
334 {
335 return next_vcpu_id;
336 }