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