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