1 | /* |
2 | * replay-internal.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 "sysemu/replay.h" |
14 | #include "sysemu/runstate.h" |
15 | #include "replay-internal.h" |
16 | #include "qemu/error-report.h" |
17 | #include "qemu/main-loop.h" |
18 | |
19 | /* Mutex to protect reading and writing events to the log. |
20 | data_kind and has_unread_data are also protected |
21 | by this mutex. |
22 | It also protects replay events queue which stores events to be |
23 | written or read to the log. */ |
24 | static QemuMutex lock; |
25 | |
26 | /* File for replay writing */ |
27 | static bool write_error; |
28 | FILE *replay_file; |
29 | |
30 | static void replay_write_error(void) |
31 | { |
32 | if (!write_error) { |
33 | error_report("replay write error" ); |
34 | write_error = true; |
35 | } |
36 | } |
37 | |
38 | static void replay_read_error(void) |
39 | { |
40 | error_report("error reading the replay data" ); |
41 | exit(1); |
42 | } |
43 | |
44 | void replay_put_byte(uint8_t byte) |
45 | { |
46 | if (replay_file) { |
47 | if (putc(byte, replay_file) == EOF) { |
48 | replay_write_error(); |
49 | } |
50 | } |
51 | } |
52 | |
53 | void replay_put_event(uint8_t event) |
54 | { |
55 | assert(event < EVENT_COUNT); |
56 | replay_put_byte(event); |
57 | } |
58 | |
59 | |
60 | void replay_put_word(uint16_t word) |
61 | { |
62 | replay_put_byte(word >> 8); |
63 | replay_put_byte(word); |
64 | } |
65 | |
66 | void replay_put_dword(uint32_t dword) |
67 | { |
68 | replay_put_word(dword >> 16); |
69 | replay_put_word(dword); |
70 | } |
71 | |
72 | void replay_put_qword(int64_t qword) |
73 | { |
74 | replay_put_dword(qword >> 32); |
75 | replay_put_dword(qword); |
76 | } |
77 | |
78 | void replay_put_array(const uint8_t *buf, size_t size) |
79 | { |
80 | if (replay_file) { |
81 | replay_put_dword(size); |
82 | if (fwrite(buf, 1, size, replay_file) != size) { |
83 | replay_write_error(); |
84 | } |
85 | } |
86 | } |
87 | |
88 | uint8_t replay_get_byte(void) |
89 | { |
90 | uint8_t byte = 0; |
91 | if (replay_file) { |
92 | int r = getc(replay_file); |
93 | if (r == EOF) { |
94 | replay_read_error(); |
95 | } |
96 | byte = r; |
97 | } |
98 | return byte; |
99 | } |
100 | |
101 | uint16_t replay_get_word(void) |
102 | { |
103 | uint16_t word = 0; |
104 | if (replay_file) { |
105 | word = replay_get_byte(); |
106 | word = (word << 8) + replay_get_byte(); |
107 | } |
108 | |
109 | return word; |
110 | } |
111 | |
112 | uint32_t replay_get_dword(void) |
113 | { |
114 | uint32_t dword = 0; |
115 | if (replay_file) { |
116 | dword = replay_get_word(); |
117 | dword = (dword << 16) + replay_get_word(); |
118 | } |
119 | |
120 | return dword; |
121 | } |
122 | |
123 | int64_t replay_get_qword(void) |
124 | { |
125 | int64_t qword = 0; |
126 | if (replay_file) { |
127 | qword = replay_get_dword(); |
128 | qword = (qword << 32) + replay_get_dword(); |
129 | } |
130 | |
131 | return qword; |
132 | } |
133 | |
134 | void replay_get_array(uint8_t *buf, size_t *size) |
135 | { |
136 | if (replay_file) { |
137 | *size = replay_get_dword(); |
138 | if (fread(buf, 1, *size, replay_file) != *size) { |
139 | replay_read_error(); |
140 | } |
141 | } |
142 | } |
143 | |
144 | void replay_get_array_alloc(uint8_t **buf, size_t *size) |
145 | { |
146 | if (replay_file) { |
147 | *size = replay_get_dword(); |
148 | *buf = g_malloc(*size); |
149 | if (fread(*buf, 1, *size, replay_file) != *size) { |
150 | replay_read_error(); |
151 | } |
152 | } |
153 | } |
154 | |
155 | void replay_check_error(void) |
156 | { |
157 | if (replay_file) { |
158 | if (feof(replay_file)) { |
159 | error_report("replay file is over" ); |
160 | qemu_system_vmstop_request_prepare(); |
161 | qemu_system_vmstop_request(RUN_STATE_PAUSED); |
162 | } else if (ferror(replay_file)) { |
163 | error_report("replay file is over or something goes wrong" ); |
164 | qemu_system_vmstop_request_prepare(); |
165 | qemu_system_vmstop_request(RUN_STATE_INTERNAL_ERROR); |
166 | } |
167 | } |
168 | } |
169 | |
170 | void replay_fetch_data_kind(void) |
171 | { |
172 | if (replay_file) { |
173 | if (!replay_state.has_unread_data) { |
174 | replay_state.data_kind = replay_get_byte(); |
175 | if (replay_state.data_kind == EVENT_INSTRUCTION) { |
176 | replay_state.instruction_count = replay_get_dword(); |
177 | } |
178 | replay_check_error(); |
179 | replay_state.has_unread_data = 1; |
180 | if (replay_state.data_kind >= EVENT_COUNT) { |
181 | error_report("Replay: unknown event kind %d" , |
182 | replay_state.data_kind); |
183 | exit(1); |
184 | } |
185 | } |
186 | } |
187 | } |
188 | |
189 | void replay_finish_event(void) |
190 | { |
191 | replay_state.has_unread_data = 0; |
192 | replay_fetch_data_kind(); |
193 | } |
194 | |
195 | static __thread bool replay_locked; |
196 | |
197 | void replay_mutex_init(void) |
198 | { |
199 | qemu_mutex_init(&lock); |
200 | /* Hold the mutex while we start-up */ |
201 | qemu_mutex_lock(&lock); |
202 | replay_locked = true; |
203 | } |
204 | |
205 | bool replay_mutex_locked(void) |
206 | { |
207 | return replay_locked; |
208 | } |
209 | |
210 | /* Ordering constraints, replay_lock must be taken before BQL */ |
211 | void replay_mutex_lock(void) |
212 | { |
213 | if (replay_mode != REPLAY_MODE_NONE) { |
214 | g_assert(!qemu_mutex_iothread_locked()); |
215 | g_assert(!replay_mutex_locked()); |
216 | qemu_mutex_lock(&lock); |
217 | replay_locked = true; |
218 | } |
219 | } |
220 | |
221 | void replay_mutex_unlock(void) |
222 | { |
223 | if (replay_mode != REPLAY_MODE_NONE) { |
224 | g_assert(replay_mutex_locked()); |
225 | replay_locked = false; |
226 | qemu_mutex_unlock(&lock); |
227 | } |
228 | } |
229 | |
230 | void replay_advance_current_icount(uint64_t current_icount) |
231 | { |
232 | int diff = (int)(current_icount - replay_state.current_icount); |
233 | |
234 | /* Time can only go forward */ |
235 | assert(diff >= 0); |
236 | |
237 | if (diff > 0) { |
238 | replay_put_event(EVENT_INSTRUCTION); |
239 | replay_put_dword(diff); |
240 | replay_state.current_icount += diff; |
241 | } |
242 | } |
243 | |
244 | /*! Saves cached instructions. */ |
245 | void replay_save_instructions(void) |
246 | { |
247 | if (replay_file && replay_mode == REPLAY_MODE_RECORD) { |
248 | g_assert(replay_mutex_locked()); |
249 | replay_advance_current_icount(replay_get_current_icount()); |
250 | } |
251 | } |
252 | |