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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 "sysemu/cpu-timers.h" | |
15 | #include "sysemu/replay.h" | |
16 | #include "sysemu/runstate.h" | |
17 | #include "replay-internal.h" | |
18 | #include "qemu/main-loop.h" | |
19 | #include "qemu/option.h" | |
20 | #include "sysemu/cpus.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 0xe0200c | |
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 | /* Replay breakpoints */ | |
38 | uint64_t replay_break_icount = -1ULL; | |
39 | QEMUTimer *replay_break_timer; | |
40 | ||
41 | bool replay_next_event_is(int event) | |
42 | { | |
43 | bool res = false; | |
44 | ||
45 | /* nothing to skip - not all instructions used */ | |
46 | if (replay_state.instruction_count != 0) { | |
47 | assert(replay_state.data_kind == EVENT_INSTRUCTION); | |
48 | return event == EVENT_INSTRUCTION; | |
49 | } | |
50 | ||
51 | while (true) { | |
52 | unsigned int data_kind = replay_state.data_kind; | |
53 | if (event == data_kind) { | |
54 | res = true; | |
55 | } | |
56 | switch (data_kind) { | |
57 | case EVENT_SHUTDOWN ... EVENT_SHUTDOWN_LAST: | |
58 | replay_finish_event(); | |
59 | qemu_system_shutdown_request(data_kind - EVENT_SHUTDOWN); | |
60 | break; | |
61 | default: | |
62 | /* clock, time_t, checkpoint and other events */ | |
63 | return res; | |
64 | } | |
65 | } | |
66 | return res; | |
67 | } | |
68 | ||
69 | uint64_t replay_get_current_icount(void) | |
70 | { | |
71 | return icount_get_raw(); | |
72 | } | |
73 | ||
74 | int replay_get_instructions(void) | |
75 | { | |
76 | int res = 0; | |
77 | replay_mutex_lock(); | |
78 | if (replay_next_event_is(EVENT_INSTRUCTION)) { | |
79 | res = replay_state.instruction_count; | |
80 | if (replay_break_icount != -1LL) { | |
81 | uint64_t current = replay_get_current_icount(); | |
82 | assert(replay_break_icount >= current); | |
83 | if (current + res > replay_break_icount) { | |
84 | res = replay_break_icount - current; | |
85 | } | |
86 | } | |
87 | } | |
88 | replay_mutex_unlock(); | |
89 | return res; | |
90 | } | |
91 | ||
92 | void replay_account_executed_instructions(void) | |
93 | { | |
94 | if (replay_mode == REPLAY_MODE_PLAY) { | |
95 | g_assert(replay_mutex_locked()); | |
96 | if (replay_state.instruction_count > 0) { | |
97 | replay_advance_current_icount(replay_get_current_icount()); | |
98 | } | |
99 | } | |
100 | } | |
101 | ||
102 | bool replay_exception(void) | |
103 | { | |
104 | ||
105 | if (replay_mode == REPLAY_MODE_RECORD) { | |
106 | g_assert(replay_mutex_locked()); | |
107 | replay_save_instructions(); | |
108 | replay_put_event(EVENT_EXCEPTION); | |
109 | return true; | |
110 | } else if (replay_mode == REPLAY_MODE_PLAY) { | |
111 | g_assert(replay_mutex_locked()); | |
112 | bool res = replay_has_exception(); | |
113 | if (res) { | |
114 | replay_finish_event(); | |
115 | } | |
116 | return res; | |
117 | } | |
118 | ||
119 | return true; | |
120 | } | |
121 | ||
122 | bool replay_has_exception(void) | |
123 | { | |
124 | bool res = false; | |
125 | if (replay_mode == REPLAY_MODE_PLAY) { | |
126 | g_assert(replay_mutex_locked()); | |
127 | replay_account_executed_instructions(); | |
128 | res = replay_next_event_is(EVENT_EXCEPTION); | |
129 | } | |
130 | ||
131 | return res; | |
132 | } | |
133 | ||
134 | bool replay_interrupt(void) | |
135 | { | |
136 | if (replay_mode == REPLAY_MODE_RECORD) { | |
137 | g_assert(replay_mutex_locked()); | |
138 | replay_save_instructions(); | |
139 | replay_put_event(EVENT_INTERRUPT); | |
140 | return true; | |
141 | } else if (replay_mode == REPLAY_MODE_PLAY) { | |
142 | g_assert(replay_mutex_locked()); | |
143 | bool res = replay_has_interrupt(); | |
144 | if (res) { | |
145 | replay_finish_event(); | |
146 | } | |
147 | return res; | |
148 | } | |
149 | ||
150 | return true; | |
151 | } | |
152 | ||
153 | bool replay_has_interrupt(void) | |
154 | { | |
155 | bool res = false; | |
156 | if (replay_mode == REPLAY_MODE_PLAY) { | |
157 | g_assert(replay_mutex_locked()); | |
158 | replay_account_executed_instructions(); | |
159 | res = replay_next_event_is(EVENT_INTERRUPT); | |
160 | } | |
161 | return res; | |
162 | } | |
163 | ||
164 | void replay_shutdown_request(ShutdownCause cause) | |
165 | { | |
166 | if (replay_mode == REPLAY_MODE_RECORD) { | |
167 | g_assert(replay_mutex_locked()); | |
168 | replay_put_event(EVENT_SHUTDOWN + cause); | |
169 | } | |
170 | } | |
171 | ||
172 | bool replay_checkpoint(ReplayCheckpoint checkpoint) | |
173 | { | |
174 | assert(EVENT_CHECKPOINT + checkpoint <= EVENT_CHECKPOINT_LAST); | |
175 | ||
176 | replay_save_instructions(); | |
177 | ||
178 | if (replay_mode == REPLAY_MODE_PLAY) { | |
179 | g_assert(replay_mutex_locked()); | |
180 | if (replay_next_event_is(EVENT_CHECKPOINT + checkpoint)) { | |
181 | replay_finish_event(); | |
182 | } else { | |
183 | return false; | |
184 | } | |
185 | } else if (replay_mode == REPLAY_MODE_RECORD) { | |
186 | g_assert(replay_mutex_locked()); | |
187 | replay_put_event(EVENT_CHECKPOINT + checkpoint); | |
188 | } | |
189 | return true; | |
190 | } | |
191 | ||
192 | void replay_async_events(void) | |
193 | { | |
194 | static bool processing = false; | |
195 | /* | |
196 | * If we are already processing the events, recursion may occur | |
197 | * in case of incorrect implementation when HW event modifies timers. | |
198 | * Timer modification may invoke the icount warp, event processing, | |
199 | * and cause the recursion. | |
200 | */ | |
201 | g_assert(!processing); | |
202 | processing = true; | |
203 | ||
204 | replay_save_instructions(); | |
205 | ||
206 | if (replay_mode == REPLAY_MODE_PLAY) { | |
207 | g_assert(replay_mutex_locked()); | |
208 | replay_read_events(); | |
209 | } else if (replay_mode == REPLAY_MODE_RECORD) { | |
210 | g_assert(replay_mutex_locked()); | |
211 | replay_save_events(); | |
212 | } | |
213 | processing = false; | |
214 | } | |
215 | ||
216 | bool replay_has_event(void) | |
217 | { | |
218 | bool res = false; | |
219 | if (replay_mode == REPLAY_MODE_PLAY) { | |
220 | g_assert(replay_mutex_locked()); | |
221 | replay_account_executed_instructions(); | |
222 | res = EVENT_CHECKPOINT <= replay_state.data_kind | |
223 | && replay_state.data_kind <= EVENT_CHECKPOINT_LAST; | |
224 | res = res || (EVENT_ASYNC <= replay_state.data_kind | |
225 | && replay_state.data_kind <= EVENT_ASYNC_LAST); | |
226 | } | |
227 | return res; | |
228 | } | |
229 | ||
230 | static void replay_enable(const char *fname, int mode) | |
231 | { | |
232 | const char *fmode = NULL; | |
233 | assert(!replay_file); | |
234 | ||
235 | switch (mode) { | |
236 | case REPLAY_MODE_RECORD: | |
237 | fmode = "wb"; | |
238 | break; | |
239 | case REPLAY_MODE_PLAY: | |
240 | fmode = "rb"; | |
241 | break; | |
242 | default: | |
243 | fprintf(stderr, "Replay: internal error: invalid replay mode\n"); | |
244 | exit(1); | |
245 | } | |
246 | ||
247 | atexit(replay_finish); | |
248 | ||
249 | replay_file = fopen(fname, fmode); | |
250 | if (replay_file == NULL) { | |
251 | fprintf(stderr, "Replay: open %s: %s\n", fname, strerror(errno)); | |
252 | exit(1); | |
253 | } | |
254 | ||
255 | replay_filename = g_strdup(fname); | |
256 | replay_mode = mode; | |
257 | replay_mutex_init(); | |
258 | ||
259 | replay_state.data_kind = -1; | |
260 | replay_state.instruction_count = 0; | |
261 | replay_state.current_icount = 0; | |
262 | replay_state.has_unread_data = 0; | |
263 | ||
264 | /* skip file header for RECORD and check it for PLAY */ | |
265 | if (replay_mode == REPLAY_MODE_RECORD) { | |
266 | fseek(replay_file, HEADER_SIZE, SEEK_SET); | |
267 | } else if (replay_mode == REPLAY_MODE_PLAY) { | |
268 | unsigned int version = replay_get_dword(); | |
269 | if (version != REPLAY_VERSION) { | |
270 | fprintf(stderr, "Replay: invalid input log file version\n"); | |
271 | exit(1); | |
272 | } | |
273 | /* go to the beginning */ | |
274 | fseek(replay_file, HEADER_SIZE, SEEK_SET); | |
275 | replay_fetch_data_kind(); | |
276 | } | |
277 | ||
278 | replay_init_events(); | |
279 | } | |
280 | ||
281 | void replay_configure(QemuOpts *opts) | |
282 | { | |
283 | const char *fname; | |
284 | const char *rr; | |
285 | ReplayMode mode = REPLAY_MODE_NONE; | |
286 | Location loc; | |
287 | ||
288 | if (!opts) { | |
289 | return; | |
290 | } | |
291 | ||
292 | loc_push_none(&loc); | |
293 | qemu_opts_loc_restore(opts); | |
294 | ||
295 | rr = qemu_opt_get(opts, "rr"); | |
296 | if (!rr) { | |
297 | /* Just enabling icount */ | |
298 | goto out; | |
299 | } else if (!strcmp(rr, "record")) { | |
300 | mode = REPLAY_MODE_RECORD; | |
301 | } else if (!strcmp(rr, "replay")) { | |
302 | mode = REPLAY_MODE_PLAY; | |
303 | } else { | |
304 | error_report("Invalid icount rr option: %s", rr); | |
305 | exit(1); | |
306 | } | |
307 | ||
308 | fname = qemu_opt_get(opts, "rrfile"); | |
309 | if (!fname) { | |
310 | error_report("File name not specified for replay"); | |
311 | exit(1); | |
312 | } | |
313 | ||
314 | replay_snapshot = g_strdup(qemu_opt_get(opts, "rrsnapshot")); | |
315 | replay_vmstate_register(); | |
316 | replay_enable(fname, mode); | |
317 | ||
318 | out: | |
319 | loc_pop(&loc); | |
320 | } | |
321 | ||
322 | void replay_start(void) | |
323 | { | |
324 | if (replay_mode == REPLAY_MODE_NONE) { | |
325 | return; | |
326 | } | |
327 | ||
328 | if (replay_blockers) { | |
329 | error_reportf_err(replay_blockers->data, "Record/replay: "); | |
330 | exit(1); | |
331 | } | |
332 | if (!icount_enabled()) { | |
333 | error_report("Please enable icount to use record/replay"); | |
334 | exit(1); | |
335 | } | |
336 | ||
337 | /* Timer for snapshotting will be set up here. */ | |
338 | ||
339 | replay_enable_events(); | |
340 | } | |
341 | ||
342 | void replay_finish(void) | |
343 | { | |
344 | if (replay_mode == REPLAY_MODE_NONE) { | |
345 | return; | |
346 | } | |
347 | ||
348 | replay_save_instructions(); | |
349 | ||
350 | /* finalize the file */ | |
351 | if (replay_file) { | |
352 | if (replay_mode == REPLAY_MODE_RECORD) { | |
353 | /* | |
354 | * Can't do it in the signal handler, therefore | |
355 | * add shutdown event here for the case of Ctrl-C. | |
356 | */ | |
357 | replay_shutdown_request(SHUTDOWN_CAUSE_HOST_SIGNAL); | |
358 | /* write end event */ | |
359 | replay_put_event(EVENT_END); | |
360 | ||
361 | /* write header */ | |
362 | fseek(replay_file, 0, SEEK_SET); | |
363 | replay_put_dword(REPLAY_VERSION); | |
364 | } | |
365 | ||
366 | fclose(replay_file); | |
367 | replay_file = NULL; | |
368 | } | |
369 | if (replay_filename) { | |
370 | g_free(replay_filename); | |
371 | replay_filename = NULL; | |
372 | } | |
373 | ||
374 | g_free(replay_snapshot); | |
375 | replay_snapshot = NULL; | |
376 | ||
377 | replay_finish_events(); | |
378 | replay_mode = REPLAY_MODE_NONE; | |
379 | } | |
380 | ||
381 | void replay_add_blocker(Error *reason) | |
382 | { | |
383 | replay_blockers = g_slist_prepend(replay_blockers, reason); | |
384 | } | |
385 | ||
386 | const char *replay_get_filename(void) | |
387 | { | |
388 | return replay_filename; | |
389 | } |