xref: /openbmc/qemu/replay/replay-snapshot.c (revision 4921d0a7)
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 = 3,
51     .minimum_version_id = 3,
52     .pre_save = replay_pre_save,
53     .post_load = replay_post_load,
54     .fields = (const 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(current_event, ReplayState),
59         VMSTATE_UINT32(data_kind, ReplayState),
60         VMSTATE_BOOL(has_unread_data, ReplayState),
61         VMSTATE_UINT64(file_offset, ReplayState),
62         VMSTATE_UINT64(block_request_id, ReplayState),
63         VMSTATE_UINT64(read_event_id, ReplayState),
64         VMSTATE_END_OF_LIST()
65     },
66 };
67 
68 void replay_vmstate_register(void)
69 {
70     vmstate_register(NULL, 0, &vmstate_replay, &replay_state);
71 }
72 
73 void replay_vmstate_init(void)
74 {
75     Error *err = NULL;
76 
77     if (replay_snapshot) {
78         if (replay_mode == REPLAY_MODE_RECORD) {
79             if (!save_snapshot(replay_snapshot,
80                                true, NULL, false, NULL, &err)) {
81                 error_report_err(err);
82                 error_report("Could not create snapshot for icount record");
83                 exit(1);
84             }
85         } else if (replay_mode == REPLAY_MODE_PLAY) {
86             if (!load_snapshot(replay_snapshot, NULL, false, NULL, &err)) {
87                 error_report_err(err);
88                 error_report("Could not load snapshot for icount replay");
89                 exit(1);
90             }
91         }
92     }
93 }
94 
95 bool replay_can_snapshot(void)
96 {
97     return replay_mode == REPLAY_MODE_NONE
98         || !replay_has_events();
99 }
100