| /* |
| * replay-internal.c |
| * |
| * Copyright (c) 2010-2015 Institute for System Programming |
| * of the Russian Academy of Sciences. |
| * |
| * This work is licensed under the terms of the GNU GPL, version 2 or later. |
| * See the COPYING file in the top-level directory. |
| * |
| */ |
| |
| #include "qemu/osdep.h" |
| #include "sysemu/replay.h" |
| #include "sysemu/runstate.h" |
| #include "replay-internal.h" |
| #include "qemu/error-report.h" |
| #include "qemu/main-loop.h" |
| |
| /* Mutex to protect reading and writing events to the log. |
| data_kind and has_unread_data are also protected |
| by this mutex. |
| It also protects replay events queue which stores events to be |
| written or read to the log. */ |
| static QemuMutex lock; |
| /* Condition and queue for fair ordering of mutex lock requests. */ |
| static QemuCond mutex_cond; |
| static unsigned long mutex_head, mutex_tail; |
| |
| /* File for replay writing */ |
| static bool write_error; |
| FILE *replay_file; |
| |
| static void replay_write_error(void) |
| { |
| if (!write_error) { |
| error_report("replay write error"); |
| write_error = true; |
| } |
| } |
| |
| static void replay_read_error(void) |
| { |
| error_report("error reading the replay data"); |
| exit(1); |
| } |
| |
| void replay_put_byte(uint8_t byte) |
| { |
| if (replay_file) { |
| if (putc(byte, replay_file) == EOF) { |
| replay_write_error(); |
| } |
| } |
| } |
| |
| void replay_put_event(uint8_t event) |
| { |
| assert(event < EVENT_COUNT); |
| replay_put_byte(event); |
| } |
| |
| |
| void replay_put_word(uint16_t word) |
| { |
| replay_put_byte(word >> 8); |
| replay_put_byte(word); |
| } |
| |
| void replay_put_dword(uint32_t dword) |
| { |
| replay_put_word(dword >> 16); |
| replay_put_word(dword); |
| } |
| |
| void replay_put_qword(int64_t qword) |
| { |
| replay_put_dword(qword >> 32); |
| replay_put_dword(qword); |
| } |
| |
| void replay_put_array(const uint8_t *buf, size_t size) |
| { |
| if (replay_file) { |
| replay_put_dword(size); |
| if (fwrite(buf, 1, size, replay_file) != size) { |
| replay_write_error(); |
| } |
| } |
| } |
| |
| uint8_t replay_get_byte(void) |
| { |
| uint8_t byte = 0; |
| if (replay_file) { |
| int r = getc(replay_file); |
| if (r == EOF) { |
| replay_read_error(); |
| } |
| byte = r; |
| } |
| return byte; |
| } |
| |
| uint16_t replay_get_word(void) |
| { |
| uint16_t word = 0; |
| if (replay_file) { |
| word = replay_get_byte(); |
| word = (word << 8) + replay_get_byte(); |
| } |
| |
| return word; |
| } |
| |
| uint32_t replay_get_dword(void) |
| { |
| uint32_t dword = 0; |
| if (replay_file) { |
| dword = replay_get_word(); |
| dword = (dword << 16) + replay_get_word(); |
| } |
| |
| return dword; |
| } |
| |
| int64_t replay_get_qword(void) |
| { |
| int64_t qword = 0; |
| if (replay_file) { |
| qword = replay_get_dword(); |
| qword = (qword << 32) + replay_get_dword(); |
| } |
| |
| return qword; |
| } |
| |
| void replay_get_array(uint8_t *buf, size_t *size) |
| { |
| if (replay_file) { |
| *size = replay_get_dword(); |
| if (fread(buf, 1, *size, replay_file) != *size) { |
| replay_read_error(); |
| } |
| } |
| } |
| |
| void replay_get_array_alloc(uint8_t **buf, size_t *size) |
| { |
| if (replay_file) { |
| *size = replay_get_dword(); |
| *buf = g_malloc(*size); |
| if (fread(*buf, 1, *size, replay_file) != *size) { |
| replay_read_error(); |
| } |
| } |
| } |
| |
| void replay_check_error(void) |
| { |
| if (replay_file) { |
| if (feof(replay_file)) { |
| error_report("replay file is over"); |
| qemu_system_vmstop_request_prepare(); |
| qemu_system_vmstop_request(RUN_STATE_PAUSED); |
| } else if (ferror(replay_file)) { |
| error_report("replay file is over or something goes wrong"); |
| qemu_system_vmstop_request_prepare(); |
| qemu_system_vmstop_request(RUN_STATE_INTERNAL_ERROR); |
| } |
| } |
| } |
| |
| void replay_fetch_data_kind(void) |
| { |
| if (replay_file) { |
| if (!replay_state.has_unread_data) { |
| replay_state.data_kind = replay_get_byte(); |
| if (replay_state.data_kind == EVENT_INSTRUCTION) { |
| replay_state.instruction_count = replay_get_dword(); |
| } |
| replay_check_error(); |
| replay_state.has_unread_data = 1; |
| if (replay_state.data_kind >= EVENT_COUNT) { |
| error_report("Replay: unknown event kind %d", |
| replay_state.data_kind); |
| exit(1); |
| } |
| } |
| } |
| } |
| |
| void replay_finish_event(void) |
| { |
| replay_state.has_unread_data = 0; |
| replay_fetch_data_kind(); |
| } |
| |
| static __thread bool replay_locked; |
| |
| void replay_mutex_init(void) |
| { |
| qemu_mutex_init(&lock); |
| qemu_cond_init(&mutex_cond); |
| /* Hold the mutex while we start-up */ |
| replay_locked = true; |
| ++mutex_tail; |
| } |
| |
| bool replay_mutex_locked(void) |
| { |
| return replay_locked; |
| } |
| |
| /* Ordering constraints, replay_lock must be taken before BQL */ |
| void replay_mutex_lock(void) |
| { |
| if (replay_mode != REPLAY_MODE_NONE) { |
| unsigned long id; |
| g_assert(!bql_locked()); |
| g_assert(!replay_mutex_locked()); |
| qemu_mutex_lock(&lock); |
| id = mutex_tail++; |
| while (id != mutex_head) { |
| qemu_cond_wait(&mutex_cond, &lock); |
| } |
| replay_locked = true; |
| qemu_mutex_unlock(&lock); |
| } |
| } |
| |
| void replay_mutex_unlock(void) |
| { |
| if (replay_mode != REPLAY_MODE_NONE) { |
| g_assert(replay_mutex_locked()); |
| qemu_mutex_lock(&lock); |
| ++mutex_head; |
| replay_locked = false; |
| qemu_cond_broadcast(&mutex_cond); |
| qemu_mutex_unlock(&lock); |
| } |
| } |
| |
| void replay_advance_current_icount(uint64_t current_icount) |
| { |
| int diff = (int)(current_icount - replay_state.current_icount); |
| |
| /* Time can only go forward */ |
| assert(diff >= 0); |
| |
| if (replay_mode == REPLAY_MODE_RECORD) { |
| if (diff > 0) { |
| replay_put_event(EVENT_INSTRUCTION); |
| replay_put_dword(diff); |
| replay_state.current_icount += diff; |
| } |
| } else if (replay_mode == REPLAY_MODE_PLAY) { |
| if (diff > 0) { |
| replay_state.instruction_count -= diff; |
| replay_state.current_icount += diff; |
| if (replay_state.instruction_count == 0) { |
| assert(replay_state.data_kind == EVENT_INSTRUCTION); |
| replay_finish_event(); |
| /* Wake up iothread. This is required because |
| timers will not expire until clock counters |
| will be read from the log. */ |
| qemu_notify_event(); |
| } |
| } |
| /* Execution reached the break step */ |
| if (replay_break_icount == replay_state.current_icount) { |
| /* Cannot make callback directly from the vCPU thread */ |
| timer_mod_ns(replay_break_timer, |
| qemu_clock_get_ns(QEMU_CLOCK_REALTIME)); |
| } |
| } |
| } |
| |
| /*! Saves cached instructions. */ |
| void replay_save_instructions(void) |
| { |
| if (replay_file && replay_mode == REPLAY_MODE_RECORD) { |
| g_assert(replay_mutex_locked()); |
| replay_advance_current_icount(replay_get_current_icount()); |
| } |
| } |