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1 | /* | |
2 | * replay.c | |
3 | * | |
4 | * Copyright (c) 2010-2015 Institute for System Programming | |
5 | * of the Russian Academy of Sciences. | |
6 | * | |
7 | * This work is licensed under the terms of the GNU GPL, version 2 or later. | |
8 | * See the COPYING file in the top-level directory. | |
9 | * | |
10 | */ | |
11 | ||
12 | #include "qemu/osdep.h" | |
13 | #include "qapi/error.h" | |
14 | #include "qemu-common.h" | |
15 | #include "sysemu/replay.h" | |
16 | #include "replay-internal.h" | |
17 | #include "qemu/timer.h" | |
18 | #include "qemu/main-loop.h" | |
19 | #include "sysemu/cpus.h" | |
20 | #include "sysemu/sysemu.h" | |
21 | #include "qemu/error-report.h" | |
22 | ||
23 | /* Current version of the replay mechanism. | |
24 | Increase it when file format changes. */ | |
25 | #define REPLAY_VERSION 0xe02005 | |
26 | /* Size of replay log header */ | |
27 | #define HEADER_SIZE (sizeof(uint32_t) + sizeof(uint64_t)) | |
28 | ||
29 | ReplayMode replay_mode = REPLAY_MODE_NONE; | |
30 | char *replay_snapshot; | |
31 | ||
32 | /* Name of replay file */ | |
33 | static char *replay_filename; | |
34 | ReplayState replay_state; | |
35 | static GSList *replay_blockers; | |
36 | ||
37 | bool replay_next_event_is(int event) | |
38 | { | |
39 | bool res = false; | |
40 | ||
41 | /* nothing to skip - not all instructions used */ | |
42 | if (replay_state.instructions_count != 0) { | |
43 | assert(replay_state.data_kind == EVENT_INSTRUCTION); | |
44 | return event == EVENT_INSTRUCTION; | |
45 | } | |
46 | ||
47 | while (true) { | |
48 | if (event == replay_state.data_kind) { | |
49 | res = true; | |
50 | } | |
51 | switch (replay_state.data_kind) { | |
52 | case EVENT_SHUTDOWN: | |
53 | replay_finish_event(); | |
54 | qemu_system_shutdown_request(); | |
55 | break; | |
56 | default: | |
57 | /* clock, time_t, checkpoint and other events */ | |
58 | return res; | |
59 | } | |
60 | } | |
61 | return res; | |
62 | } | |
63 | ||
64 | uint64_t replay_get_current_step(void) | |
65 | { | |
66 | return cpu_get_icount_raw(); | |
67 | } | |
68 | ||
69 | int replay_get_instructions(void) | |
70 | { | |
71 | int res = 0; | |
72 | replay_mutex_lock(); | |
73 | if (replay_next_event_is(EVENT_INSTRUCTION)) { | |
74 | res = replay_state.instructions_count; | |
75 | } | |
76 | replay_mutex_unlock(); | |
77 | return res; | |
78 | } | |
79 | ||
80 | void replay_account_executed_instructions(void) | |
81 | { | |
82 | if (replay_mode == REPLAY_MODE_PLAY) { | |
83 | replay_mutex_lock(); | |
84 | if (replay_state.instructions_count > 0) { | |
85 | int count = (int)(replay_get_current_step() | |
86 | - replay_state.current_step); | |
87 | replay_state.instructions_count -= count; | |
88 | replay_state.current_step += count; | |
89 | if (replay_state.instructions_count == 0) { | |
90 | assert(replay_state.data_kind == EVENT_INSTRUCTION); | |
91 | replay_finish_event(); | |
92 | /* Wake up iothread. This is required because | |
93 | timers will not expire until clock counters | |
94 | will be read from the log. */ | |
95 | qemu_notify_event(); | |
96 | } | |
97 | } | |
98 | replay_mutex_unlock(); | |
99 | } | |
100 | } | |
101 | ||
102 | bool replay_exception(void) | |
103 | { | |
104 | if (replay_mode == REPLAY_MODE_RECORD) { | |
105 | replay_save_instructions(); | |
106 | replay_mutex_lock(); | |
107 | replay_put_event(EVENT_EXCEPTION); | |
108 | replay_mutex_unlock(); | |
109 | return true; | |
110 | } else if (replay_mode == REPLAY_MODE_PLAY) { | |
111 | bool res = replay_has_exception(); | |
112 | if (res) { | |
113 | replay_mutex_lock(); | |
114 | replay_finish_event(); | |
115 | replay_mutex_unlock(); | |
116 | } | |
117 | return res; | |
118 | } | |
119 | ||
120 | return true; | |
121 | } | |
122 | ||
123 | bool replay_has_exception(void) | |
124 | { | |
125 | bool res = false; | |
126 | if (replay_mode == REPLAY_MODE_PLAY) { | |
127 | replay_account_executed_instructions(); | |
128 | replay_mutex_lock(); | |
129 | res = replay_next_event_is(EVENT_EXCEPTION); | |
130 | replay_mutex_unlock(); | |
131 | } | |
132 | ||
133 | return res; | |
134 | } | |
135 | ||
136 | bool replay_interrupt(void) | |
137 | { | |
138 | if (replay_mode == REPLAY_MODE_RECORD) { | |
139 | replay_save_instructions(); | |
140 | replay_mutex_lock(); | |
141 | replay_put_event(EVENT_INTERRUPT); | |
142 | replay_mutex_unlock(); | |
143 | return true; | |
144 | } else if (replay_mode == REPLAY_MODE_PLAY) { | |
145 | bool res = replay_has_interrupt(); | |
146 | if (res) { | |
147 | replay_mutex_lock(); | |
148 | replay_finish_event(); | |
149 | replay_mutex_unlock(); | |
150 | } | |
151 | return res; | |
152 | } | |
153 | ||
154 | return true; | |
155 | } | |
156 | ||
157 | bool replay_has_interrupt(void) | |
158 | { | |
159 | bool res = false; | |
160 | if (replay_mode == REPLAY_MODE_PLAY) { | |
161 | replay_account_executed_instructions(); | |
162 | replay_mutex_lock(); | |
163 | res = replay_next_event_is(EVENT_INTERRUPT); | |
164 | replay_mutex_unlock(); | |
165 | } | |
166 | return res; | |
167 | } | |
168 | ||
169 | void replay_shutdown_request(void) | |
170 | { | |
171 | if (replay_mode == REPLAY_MODE_RECORD) { | |
172 | replay_mutex_lock(); | |
173 | replay_put_event(EVENT_SHUTDOWN); | |
174 | replay_mutex_unlock(); | |
175 | } | |
176 | } | |
177 | ||
178 | bool replay_checkpoint(ReplayCheckpoint checkpoint) | |
179 | { | |
180 | bool res = false; | |
181 | assert(EVENT_CHECKPOINT + checkpoint <= EVENT_CHECKPOINT_LAST); | |
182 | replay_save_instructions(); | |
183 | ||
184 | if (!replay_file) { | |
185 | return true; | |
186 | } | |
187 | ||
188 | replay_mutex_lock(); | |
189 | ||
190 | if (replay_mode == REPLAY_MODE_PLAY) { | |
191 | if (replay_next_event_is(EVENT_CHECKPOINT + checkpoint)) { | |
192 | replay_finish_event(); | |
193 | } else if (replay_state.data_kind != EVENT_ASYNC) { | |
194 | res = false; | |
195 | goto out; | |
196 | } | |
197 | replay_read_events(checkpoint); | |
198 | /* replay_read_events may leave some unread events. | |
199 | Return false if not all of the events associated with | |
200 | checkpoint were processed */ | |
201 | res = replay_state.data_kind != EVENT_ASYNC; | |
202 | } else if (replay_mode == REPLAY_MODE_RECORD) { | |
203 | replay_put_event(EVENT_CHECKPOINT + checkpoint); | |
204 | replay_save_events(checkpoint); | |
205 | res = true; | |
206 | } | |
207 | out: | |
208 | replay_mutex_unlock(); | |
209 | return res; | |
210 | } | |
211 | ||
212 | static void replay_enable(const char *fname, int mode) | |
213 | { | |
214 | const char *fmode = NULL; | |
215 | assert(!replay_file); | |
216 | ||
217 | switch (mode) { | |
218 | case REPLAY_MODE_RECORD: | |
219 | fmode = "wb"; | |
220 | break; | |
221 | case REPLAY_MODE_PLAY: | |
222 | fmode = "rb"; | |
223 | break; | |
224 | default: | |
225 | fprintf(stderr, "Replay: internal error: invalid replay mode\n"); | |
226 | exit(1); | |
227 | } | |
228 | ||
229 | atexit(replay_finish); | |
230 | ||
231 | replay_mutex_init(); | |
232 | ||
233 | replay_file = fopen(fname, fmode); | |
234 | if (replay_file == NULL) { | |
235 | fprintf(stderr, "Replay: open %s: %s\n", fname, strerror(errno)); | |
236 | exit(1); | |
237 | } | |
238 | ||
239 | replay_filename = g_strdup(fname); | |
240 | ||
241 | replay_mode = mode; | |
242 | replay_state.data_kind = -1; | |
243 | replay_state.instructions_count = 0; | |
244 | replay_state.current_step = 0; | |
245 | replay_state.has_unread_data = 0; | |
246 | ||
247 | /* skip file header for RECORD and check it for PLAY */ | |
248 | if (replay_mode == REPLAY_MODE_RECORD) { | |
249 | fseek(replay_file, HEADER_SIZE, SEEK_SET); | |
250 | } else if (replay_mode == REPLAY_MODE_PLAY) { | |
251 | unsigned int version = replay_get_dword(); | |
252 | if (version != REPLAY_VERSION) { | |
253 | fprintf(stderr, "Replay: invalid input log file version\n"); | |
254 | exit(1); | |
255 | } | |
256 | /* go to the beginning */ | |
257 | fseek(replay_file, HEADER_SIZE, SEEK_SET); | |
258 | replay_fetch_data_kind(); | |
259 | } | |
260 | ||
261 | replay_init_events(); | |
262 | } | |
263 | ||
264 | void replay_configure(QemuOpts *opts) | |
265 | { | |
266 | const char *fname; | |
267 | const char *rr; | |
268 | ReplayMode mode = REPLAY_MODE_NONE; | |
269 | Location loc; | |
270 | ||
271 | if (!opts) { | |
272 | return; | |
273 | } | |
274 | ||
275 | loc_push_none(&loc); | |
276 | qemu_opts_loc_restore(opts); | |
277 | ||
278 | rr = qemu_opt_get(opts, "rr"); | |
279 | if (!rr) { | |
280 | /* Just enabling icount */ | |
281 | goto out; | |
282 | } else if (!strcmp(rr, "record")) { | |
283 | mode = REPLAY_MODE_RECORD; | |
284 | } else if (!strcmp(rr, "replay")) { | |
285 | mode = REPLAY_MODE_PLAY; | |
286 | } else { | |
287 | error_report("Invalid icount rr option: %s", rr); | |
288 | exit(1); | |
289 | } | |
290 | ||
291 | fname = qemu_opt_get(opts, "rrfile"); | |
292 | if (!fname) { | |
293 | error_report("File name not specified for replay"); | |
294 | exit(1); | |
295 | } | |
296 | ||
297 | replay_snapshot = g_strdup(qemu_opt_get(opts, "rrsnapshot")); | |
298 | replay_vmstate_register(); | |
299 | replay_enable(fname, mode); | |
300 | ||
301 | out: | |
302 | loc_pop(&loc); | |
303 | } | |
304 | ||
305 | void replay_start(void) | |
306 | { | |
307 | if (replay_mode == REPLAY_MODE_NONE) { | |
308 | return; | |
309 | } | |
310 | ||
311 | if (replay_blockers) { | |
312 | error_reportf_err(replay_blockers->data, "Record/replay: "); | |
313 | exit(1); | |
314 | } | |
315 | if (!use_icount) { | |
316 | error_report("Please enable icount to use record/replay"); | |
317 | exit(1); | |
318 | } | |
319 | ||
320 | /* Timer for snapshotting will be set up here. */ | |
321 | ||
322 | replay_enable_events(); | |
323 | } | |
324 | ||
325 | void replay_finish(void) | |
326 | { | |
327 | if (replay_mode == REPLAY_MODE_NONE) { | |
328 | return; | |
329 | } | |
330 | ||
331 | replay_save_instructions(); | |
332 | ||
333 | /* finalize the file */ | |
334 | if (replay_file) { | |
335 | if (replay_mode == REPLAY_MODE_RECORD) { | |
336 | /* write end event */ | |
337 | replay_put_event(EVENT_END); | |
338 | ||
339 | /* write header */ | |
340 | fseek(replay_file, 0, SEEK_SET); | |
341 | replay_put_dword(REPLAY_VERSION); | |
342 | } | |
343 | ||
344 | fclose(replay_file); | |
345 | replay_file = NULL; | |
346 | } | |
347 | if (replay_filename) { | |
348 | g_free(replay_filename); | |
349 | replay_filename = NULL; | |
350 | } | |
351 | ||
352 | g_free(replay_snapshot); | |
353 | replay_snapshot = NULL; | |
354 | ||
355 | replay_finish_events(); | |
356 | replay_mutex_destroy(); | |
357 | } | |
358 | ||
359 | void replay_add_blocker(Error *reason) | |
360 | { | |
361 | replay_blockers = g_slist_prepend(replay_blockers, reason); | |
362 | } |