Merge remote-tracking branch 'remotes/edgar/tags/edgar/cris-next-2021-02-22.for-upstr...
[qemu.git] / block / blkreplay.c
1 /*
2 * Block protocol for record/replay
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 "qemu/module.h"
14 #include "block/block_int.h"
15 #include "sysemu/replay.h"
16 #include "qapi/error.h"
17
18 typedef struct Request {
19 Coroutine *co;
20 QEMUBH *bh;
21 } Request;
22
23 static int blkreplay_open(BlockDriverState *bs, QDict *options, int flags,
24 Error **errp)
25 {
26 Error *local_err = NULL;
27 int ret;
28
29 /* Open the image file */
30 bs->file = bdrv_open_child(NULL, options, "image", bs, &child_of_bds,
31 BDRV_CHILD_FILTERED | BDRV_CHILD_PRIMARY,
32 false, &local_err);
33 if (local_err) {
34 ret = -EINVAL;
35 error_propagate(errp, local_err);
36 goto fail;
37 }
38
39 bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED;
40 bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED;
41
42 ret = 0;
43 fail:
44 return ret;
45 }
46
47 static int64_t blkreplay_getlength(BlockDriverState *bs)
48 {
49 return bdrv_getlength(bs->file->bs);
50 }
51
52 /* This bh is used for synchronization of return from coroutines.
53 It continues yielded coroutine which then finishes its execution.
54 BH is called adjusted to some replay checkpoint, therefore
55 record and replay will always finish coroutines deterministically.
56 */
57 static void blkreplay_bh_cb(void *opaque)
58 {
59 Request *req = opaque;
60 aio_co_wake(req->co);
61 qemu_bh_delete(req->bh);
62 g_free(req);
63 }
64
65 static void block_request_create(uint64_t reqid, BlockDriverState *bs,
66 Coroutine *co)
67 {
68 Request *req = g_new(Request, 1);
69 *req = (Request) {
70 .co = co,
71 .bh = aio_bh_new(bdrv_get_aio_context(bs), blkreplay_bh_cb, req),
72 };
73 replay_block_event(req->bh, reqid);
74 }
75
76 static int coroutine_fn blkreplay_co_preadv(BlockDriverState *bs,
77 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
78 {
79 uint64_t reqid = blkreplay_next_id();
80 int ret = bdrv_co_preadv(bs->file, offset, bytes, qiov, flags);
81 block_request_create(reqid, bs, qemu_coroutine_self());
82 qemu_coroutine_yield();
83
84 return ret;
85 }
86
87 static int coroutine_fn blkreplay_co_pwritev(BlockDriverState *bs,
88 uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
89 {
90 uint64_t reqid = blkreplay_next_id();
91 int ret = bdrv_co_pwritev(bs->file, offset, bytes, qiov, flags);
92 block_request_create(reqid, bs, qemu_coroutine_self());
93 qemu_coroutine_yield();
94
95 return ret;
96 }
97
98 static int coroutine_fn blkreplay_co_pwrite_zeroes(BlockDriverState *bs,
99 int64_t offset, int bytes, BdrvRequestFlags flags)
100 {
101 uint64_t reqid = blkreplay_next_id();
102 int ret = bdrv_co_pwrite_zeroes(bs->file, offset, bytes, flags);
103 block_request_create(reqid, bs, qemu_coroutine_self());
104 qemu_coroutine_yield();
105
106 return ret;
107 }
108
109 static int coroutine_fn blkreplay_co_pdiscard(BlockDriverState *bs,
110 int64_t offset, int bytes)
111 {
112 uint64_t reqid = blkreplay_next_id();
113 int ret = bdrv_co_pdiscard(bs->file, offset, bytes);
114 block_request_create(reqid, bs, qemu_coroutine_self());
115 qemu_coroutine_yield();
116
117 return ret;
118 }
119
120 static int coroutine_fn blkreplay_co_flush(BlockDriverState *bs)
121 {
122 uint64_t reqid = blkreplay_next_id();
123 int ret = bdrv_co_flush(bs->file->bs);
124 block_request_create(reqid, bs, qemu_coroutine_self());
125 qemu_coroutine_yield();
126
127 return ret;
128 }
129
130 static int blkreplay_snapshot_goto(BlockDriverState *bs,
131 const char *snapshot_id)
132 {
133 return bdrv_snapshot_goto(bs->file->bs, snapshot_id, NULL);
134 }
135
136 static BlockDriver bdrv_blkreplay = {
137 .format_name = "blkreplay",
138 .instance_size = 0,
139 .is_filter = true,
140
141 .bdrv_open = blkreplay_open,
142 .bdrv_child_perm = bdrv_default_perms,
143 .bdrv_getlength = blkreplay_getlength,
144
145 .bdrv_co_preadv = blkreplay_co_preadv,
146 .bdrv_co_pwritev = blkreplay_co_pwritev,
147
148 .bdrv_co_pwrite_zeroes = blkreplay_co_pwrite_zeroes,
149 .bdrv_co_pdiscard = blkreplay_co_pdiscard,
150 .bdrv_co_flush = blkreplay_co_flush,
151
152 .bdrv_snapshot_goto = blkreplay_snapshot_goto,
153 };
154
155 static void bdrv_blkreplay_init(void)
156 {
157 bdrv_register(&bdrv_blkreplay);
158 }
159
160 block_init(bdrv_blkreplay_init);