replay/replay-snapshot.c

   1 /*
   2  * replay-snapshot.c
   3  *
   4  * Copyright (c) 2010-2016 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/replay.h"
  15 #include "replay-internal.h"
  16 #include "monitor/monitor.h"
  17 #include "qapi/qmp/qstring.h"
  18 #include "qemu/error-report.h"
  19 #include "migration/vmstate.h"
  20 #include "migration/snapshot.h"
  21
  22 static int replay_pre_save(void *opaque)
  23 {
  24     ReplayState *state = opaque;
  25     state->file_offset = ftell(replay_file);
  26     state->host_clock_last = qemu_clock_get_last(QEMU_CLOCK_HOST);
  27
  28     return 0;
  29 }
  30
  31 static int replay_post_load(void *opaque, int version_id)
  32 {
  33     ReplayState *state = opaque;
  34     if (replay_mode == REPLAY_MODE_PLAY) {
  35         fseek(replay_file, state->file_offset, SEEK_SET);
  36         qemu_clock_set_last(QEMU_CLOCK_HOST, state->host_clock_last);
  37         /* If this was a vmstate, saved in recording mode,
  38            we need to initialize replay data fields. */
  39         replay_fetch_data_kind();
  40     } else if (replay_mode == REPLAY_MODE_RECORD) {
  41         /* This is only useful for loading the initial state.
  42            Therefore reset all the counters. */
  43         state->instructions_count = 0;
  44         state->block_request_id = 0;
  45     }
  46
  47     return 0;
  48 }
  49
  50 static const VMStateDescription vmstate_replay = {
  51     .name = "replay",
  52     .version_id = 1,
  53     .minimum_version_id = 1,
  54     .pre_save = replay_pre_save,
  55     .post_load = replay_post_load,
  56     .fields = (VMStateField[]) {
  57         VMSTATE_INT64_ARRAY(cached_clock, ReplayState, REPLAY_CLOCK_COUNT),
  58         VMSTATE_UINT64(current_step, ReplayState),
  59         VMSTATE_INT32(instructions_count, ReplayState),
  60         VMSTATE_UINT32(data_kind, ReplayState),
  61         VMSTATE_UINT32(has_unread_data, ReplayState),
  62         VMSTATE_UINT64(file_offset, ReplayState),
  63         VMSTATE_UINT64(block_request_id, ReplayState),
  64         VMSTATE_UINT64(host_clock_last, ReplayState),
  65         VMSTATE_INT32(read_event_kind, ReplayState),
  66         VMSTATE_UINT64(read_event_id, ReplayState),
  67         VMSTATE_INT32(read_event_checkpoint, ReplayState),
  68         VMSTATE_END_OF_LIST()
  69     },
  70 };
  71
  72 void replay_vmstate_register(void)
  73 {
  74     vmstate_register(NULL, 0, &vmstate_replay, &replay_state);
  75 }
  76
  77 void replay_vmstate_init(void)
  78 {
  79     Error *err = NULL;
  80
  81     if (replay_snapshot) {
  82         if (replay_mode == REPLAY_MODE_RECORD) {
  83             if (save_snapshot(replay_snapshot, &err) != 0) {
  84                 error_report_err(err);
  85                 error_report("Could not create snapshot for icount record");
  86                 exit(1);
  87             }
  88         } else if (replay_mode == REPLAY_MODE_PLAY) {
  89             if (load_snapshot(replay_snapshot, &err) != 0) {
  90                 error_report_err(err);
  91                 error_report("Could not load snapshot for icount replay");
  92                 exit(1);
  93             }
  94         }
  95     }
  96 }
  97
  98 bool replay_can_snapshot(void)
  99 {
 100     return replay_mode == REPLAY_MODE_NONE
 101         || !replay_has_events();
 102 }