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Commit | Line | Data |
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c163b5ca | 1 | /* |
2 | * QEMU live block migration | |
3 | * | |
4 | * Copyright IBM, Corp. 2009 | |
5 | * | |
6 | * Authors: | |
7 | * Liran Schour <lirans@il.ibm.com> | |
8 | * | |
9 | * This work is licensed under the terms of the GNU GPL, version 2. See | |
10 | * the COPYING file in the top-level directory. | |
11 | * | |
12 | */ | |
13 | ||
14 | #include "qemu-common.h" | |
15 | #include "block_int.h" | |
16 | #include "hw/hw.h" | |
5e5328be | 17 | #include "qemu-queue.h" |
c163b5ca | 18 | #include "block-migration.h" |
19 | #include <assert.h> | |
c163b5ca | 20 | |
6ea44308 | 21 | #define BLOCK_SIZE (BDRV_SECTORS_PER_DIRTY_CHUNK << BDRV_SECTOR_BITS) |
c163b5ca | 22 | |
23 | #define BLK_MIG_FLAG_DEVICE_BLOCK 0x01 | |
24 | #define BLK_MIG_FLAG_EOS 0x02 | |
25 | ||
26 | #define MAX_IS_ALLOCATED_SEARCH 65536 | |
27 | #define MAX_BLOCKS_READ 10000 | |
28 | #define BLOCKS_READ_CHANGE 100 | |
29 | #define INITIAL_BLOCKS_READ 100 | |
30 | ||
31 | //#define DEBUG_BLK_MIGRATION | |
32 | ||
33 | #ifdef DEBUG_BLK_MIGRATION | |
a55eb92c | 34 | #define dprintf(fmt, ...) \ |
c163b5ca | 35 | do { printf("blk_migration: " fmt, ## __VA_ARGS__); } while (0) |
36 | #else | |
a55eb92c | 37 | #define dprintf(fmt, ...) \ |
c163b5ca | 38 | do { } while (0) |
39 | #endif | |
40 | ||
a55eb92c JK |
41 | typedef struct BlkMigDevState { |
42 | BlockDriverState *bs; | |
43 | int bulk_completed; | |
44 | int shared_base; | |
a55eb92c JK |
45 | int64_t cur_sector; |
46 | int64_t total_sectors; | |
47 | int64_t dirty; | |
5e5328be | 48 | QSIMPLEQ_ENTRY(BlkMigDevState) entry; |
a55eb92c JK |
49 | } BlkMigDevState; |
50 | ||
c163b5ca | 51 | typedef struct BlkMigBlock { |
52 | uint8_t *buf; | |
53 | BlkMigDevState *bmds; | |
54 | int64_t sector; | |
55 | struct iovec iov; | |
56 | QEMUIOVector qiov; | |
57 | BlockDriverAIOCB *aiocb; | |
58 | int ret; | |
5e5328be | 59 | QSIMPLEQ_ENTRY(BlkMigBlock) entry; |
c163b5ca | 60 | } BlkMigBlock; |
61 | ||
62 | typedef struct BlkMigState { | |
c163b5ca | 63 | int blk_enable; |
64 | int shared_base; | |
5e5328be JK |
65 | QSIMPLEQ_HEAD(bmds_list, BlkMigDevState) bmds_list; |
66 | QSIMPLEQ_HEAD(blk_list, BlkMigBlock) blk_list; | |
c163b5ca | 67 | int submitted; |
68 | int read_done; | |
69 | int transferred; | |
70 | int64_t print_completion; | |
71 | } BlkMigState; | |
72 | ||
d11ecd3d | 73 | static BlkMigState block_mig_state; |
c163b5ca | 74 | |
75 | static void blk_mig_read_cb(void *opaque, int ret) | |
76 | { | |
77 | BlkMigBlock *blk = opaque; | |
a55eb92c | 78 | |
c163b5ca | 79 | blk->ret = ret; |
a55eb92c | 80 | |
5e5328be | 81 | QSIMPLEQ_INSERT_TAIL(&block_mig_state.blk_list, blk, entry); |
a55eb92c | 82 | |
d11ecd3d JK |
83 | block_mig_state.submitted--; |
84 | block_mig_state.read_done++; | |
85 | assert(block_mig_state.submitted >= 0); | |
c163b5ca | 86 | } |
87 | ||
57cce12d | 88 | static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds, int is_async) |
a55eb92c | 89 | { |
57cce12d JK |
90 | int64_t total_sectors = bmds->total_sectors; |
91 | int64_t cur_sector = bmds->cur_sector; | |
92 | BlockDriverState *bs = bmds->bs; | |
93 | int len, nr_sectors; | |
c163b5ca | 94 | BlkMigBlock *blk; |
57cce12d | 95 | uint8_t *tmp_buf; |
a55eb92c | 96 | |
57cce12d | 97 | if (bmds->shared_base) { |
b1d10856 | 98 | while (cur_sector < total_sectors && |
57cce12d JK |
99 | !bdrv_is_allocated(bs, cur_sector, MAX_IS_ALLOCATED_SEARCH, |
100 | &nr_sectors)) { | |
c163b5ca | 101 | cur_sector += nr_sectors; |
102 | } | |
103 | } | |
a55eb92c JK |
104 | |
105 | if (cur_sector >= total_sectors) { | |
57cce12d | 106 | bmds->cur_sector = total_sectors; |
c163b5ca | 107 | return 1; |
108 | } | |
a55eb92c | 109 | |
d11ecd3d | 110 | if (cur_sector >= block_mig_state.print_completion) { |
c163b5ca | 111 | printf("Completed %" PRId64 " %%\r", cur_sector * 100 / total_sectors); |
112 | fflush(stdout); | |
d11ecd3d | 113 | block_mig_state.print_completion += |
6ea44308 | 114 | (BDRV_SECTORS_PER_DIRTY_CHUNK * 10000); |
c163b5ca | 115 | } |
a55eb92c | 116 | |
57cce12d JK |
117 | cur_sector &= ~((int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK - 1); |
118 | ||
6ea44308 JK |
119 | /* we are going to transfer a full block even if it is not allocated */ |
120 | nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK; | |
c163b5ca | 121 | |
6ea44308 | 122 | if (total_sectors - cur_sector < BDRV_SECTORS_PER_DIRTY_CHUNK) { |
57cce12d | 123 | nr_sectors = total_sectors - cur_sector; |
c163b5ca | 124 | } |
a55eb92c | 125 | |
57cce12d JK |
126 | if (is_async) { |
127 | blk = qemu_malloc(sizeof(BlkMigBlock)); | |
128 | blk->buf = qemu_malloc(BLOCK_SIZE); | |
a55eb92c | 129 | |
57cce12d JK |
130 | bmds->cur_sector = cur_sector + nr_sectors; |
131 | blk->sector = cur_sector; | |
132 | blk->bmds = bmds; | |
a55eb92c | 133 | |
57cce12d JK |
134 | blk->iov.iov_base = blk->buf; |
135 | blk->iov.iov_len = nr_sectors * BDRV_SECTOR_SIZE; | |
136 | qemu_iovec_init_external(&blk->qiov, &blk->iov, 1); | |
a55eb92c | 137 | |
57cce12d JK |
138 | blk->aiocb = bdrv_aio_readv(bs, cur_sector, &blk->qiov, |
139 | nr_sectors, blk_mig_read_cb, blk); | |
a55eb92c | 140 | |
57cce12d JK |
141 | if (!blk->aiocb) { |
142 | printf("Error reading sector %" PRId64 "\n", cur_sector); | |
143 | qemu_free(blk->buf); | |
144 | qemu_free(blk); | |
145 | return 0; | |
146 | } | |
c163b5ca | 147 | |
57cce12d JK |
148 | bdrv_reset_dirty(bs, cur_sector, nr_sectors); |
149 | block_mig_state.submitted++; | |
a55eb92c | 150 | |
57cce12d JK |
151 | } else { |
152 | tmp_buf = qemu_malloc(BLOCK_SIZE); | |
a55eb92c | 153 | |
57cce12d JK |
154 | if (bdrv_read(bs, cur_sector, tmp_buf, nr_sectors) < 0) { |
155 | printf("Error reading sector %" PRId64 "\n", cur_sector); | |
c163b5ca | 156 | } |
a55eb92c | 157 | |
57cce12d | 158 | bdrv_reset_dirty(bs, cur_sector, nr_sectors); |
a55eb92c | 159 | |
57cce12d JK |
160 | /* sector number and flags */ |
161 | qemu_put_be64(f, (cur_sector << BDRV_SECTOR_BITS) | |
162 | | BLK_MIG_FLAG_DEVICE_BLOCK); | |
a55eb92c | 163 | |
57cce12d JK |
164 | /* device name */ |
165 | len = strlen(bs->device_name); | |
166 | qemu_put_byte(f, len); | |
167 | qemu_put_buffer(f, (uint8_t *)bs->device_name, len); | |
a55eb92c | 168 | |
57cce12d | 169 | qemu_put_buffer(f, tmp_buf, BLOCK_SIZE); |
a55eb92c | 170 | |
57cce12d | 171 | bmds->cur_sector = cur_sector + BDRV_SECTORS_PER_DIRTY_CHUNK; |
a55eb92c | 172 | |
57cce12d | 173 | qemu_free(tmp_buf); |
c163b5ca | 174 | } |
175 | ||
c163b5ca | 176 | return (bmds->cur_sector >= total_sectors); |
177 | } | |
178 | ||
179 | static void send_blk(QEMUFile *f, BlkMigBlock * blk) | |
180 | { | |
181 | int len; | |
a55eb92c JK |
182 | |
183 | /* sector number and flags */ | |
6ea44308 JK |
184 | qemu_put_be64(f, (blk->sector << BDRV_SECTOR_BITS) |
185 | | BLK_MIG_FLAG_DEVICE_BLOCK); | |
a55eb92c JK |
186 | |
187 | /* device name */ | |
c163b5ca | 188 | len = strlen(blk->bmds->bs->device_name); |
189 | qemu_put_byte(f, len); | |
190 | qemu_put_buffer(f, (uint8_t *)blk->bmds->bs->device_name, len); | |
a55eb92c JK |
191 | |
192 | qemu_put_buffer(f, blk->buf, BLOCK_SIZE); | |
c163b5ca | 193 | } |
194 | ||
c163b5ca | 195 | static void set_dirty_tracking(int enable) |
196 | { | |
197 | BlkMigDevState *bmds; | |
5e5328be JK |
198 | |
199 | QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) { | |
a55eb92c | 200 | bdrv_set_dirty_tracking(bmds->bs, enable); |
c163b5ca | 201 | } |
c163b5ca | 202 | } |
203 | ||
204 | static void init_blk_migration(QEMUFile *f) | |
205 | { | |
5e5328be | 206 | BlkMigDevState *bmds; |
c163b5ca | 207 | BlockDriverState *bs; |
a55eb92c | 208 | |
69d63a97 JK |
209 | block_mig_state.submitted = 0; |
210 | block_mig_state.read_done = 0; | |
211 | block_mig_state.transferred = 0; | |
212 | block_mig_state.print_completion = 0; | |
213 | ||
c163b5ca | 214 | for (bs = bdrv_first; bs != NULL; bs = bs->next) { |
a55eb92c | 215 | if (bs->type == BDRV_TYPE_HD) { |
c163b5ca | 216 | bmds = qemu_mallocz(sizeof(BlkMigDevState)); |
217 | bmds->bs = bs; | |
218 | bmds->bulk_completed = 0; | |
6ea44308 | 219 | bmds->total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS; |
d11ecd3d | 220 | bmds->shared_base = block_mig_state.shared_base; |
a55eb92c JK |
221 | |
222 | if (bmds->shared_base) { | |
223 | printf("Start migration for %s with shared base image\n", | |
c163b5ca | 224 | bs->device_name); |
225 | } else { | |
226 | printf("Start full migration for %s\n", bs->device_name); | |
227 | } | |
a55eb92c | 228 | |
5e5328be | 229 | QSIMPLEQ_INSERT_TAIL(&block_mig_state.bmds_list, bmds, entry); |
c163b5ca | 230 | } |
a55eb92c | 231 | } |
c163b5ca | 232 | } |
233 | ||
234 | static int blk_mig_save_bulked_block(QEMUFile *f, int is_async) | |
235 | { | |
236 | BlkMigDevState *bmds; | |
237 | ||
5e5328be | 238 | QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) { |
a55eb92c | 239 | if (bmds->bulk_completed == 0) { |
57cce12d JK |
240 | if (mig_save_device_bulk(f, bmds, is_async) == 1) { |
241 | /* completed bulk section for this device */ | |
242 | bmds->bulk_completed = 1; | |
c163b5ca | 243 | } |
244 | return 1; | |
245 | } | |
246 | } | |
a55eb92c | 247 | |
c163b5ca | 248 | /* we reached here means bulk is completed */ |
c163b5ca | 249 | return 0; |
c163b5ca | 250 | } |
251 | ||
252 | #define MAX_NUM_BLOCKS 4 | |
253 | ||
254 | static void blk_mig_save_dirty_blocks(QEMUFile *f) | |
255 | { | |
256 | BlkMigDevState *bmds; | |
575a58d7 | 257 | uint8_t *buf; |
c163b5ca | 258 | int64_t sector; |
259 | int len; | |
a55eb92c | 260 | |
575a58d7 JK |
261 | buf = qemu_malloc(BLOCK_SIZE); |
262 | ||
5e5328be | 263 | QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) { |
a55eb92c JK |
264 | for (sector = 0; sector < bmds->cur_sector;) { |
265 | if (bdrv_get_dirty(bmds->bs, sector)) { | |
266 | if (bdrv_read(bmds->bs, sector, buf, | |
6ea44308 | 267 | BDRV_SECTORS_PER_DIRTY_CHUNK) < 0) { |
a55eb92c | 268 | /* FIXME: add error handling */ |
c163b5ca | 269 | } |
a55eb92c JK |
270 | |
271 | /* sector number and flags */ | |
6ea44308 | 272 | qemu_put_be64(f, (sector << BDRV_SECTOR_BITS) |
a55eb92c JK |
273 | | BLK_MIG_FLAG_DEVICE_BLOCK); |
274 | ||
c163b5ca | 275 | /* device name */ |
c163b5ca | 276 | len = strlen(bmds->bs->device_name); |
c163b5ca | 277 | qemu_put_byte(f, len); |
278 | qemu_put_buffer(f, (uint8_t *)bmds->bs->device_name, len); | |
a55eb92c | 279 | |
6ea44308 | 280 | qemu_put_buffer(f, buf, BLOCK_SIZE); |
a55eb92c JK |
281 | |
282 | bdrv_reset_dirty(bmds->bs, sector, | |
6ea44308 | 283 | BDRV_SECTORS_PER_DIRTY_CHUNK); |
a55eb92c | 284 | } |
6ea44308 | 285 | sector += BDRV_SECTORS_PER_DIRTY_CHUNK; |
c163b5ca | 286 | } |
287 | } | |
575a58d7 JK |
288 | |
289 | qemu_free(buf); | |
c163b5ca | 290 | } |
291 | ||
292 | static void flush_blks(QEMUFile* f) | |
293 | { | |
5e5328be | 294 | BlkMigBlock *blk; |
a55eb92c | 295 | |
d11ecd3d JK |
296 | dprintf("%s Enter submitted %d read_done %d transferred %d\n", |
297 | __FUNCTION__, block_mig_state.submitted, block_mig_state.read_done, | |
298 | block_mig_state.transferred); | |
a55eb92c | 299 | |
5e5328be JK |
300 | while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) { |
301 | if (qemu_file_rate_limit(f)) { | |
302 | break; | |
303 | } | |
c163b5ca | 304 | send_blk(f, blk); |
a55eb92c | 305 | |
5e5328be | 306 | QSIMPLEQ_REMOVE_HEAD(&block_mig_state.blk_list, entry); |
c163b5ca | 307 | qemu_free(blk->buf); |
308 | qemu_free(blk); | |
a55eb92c | 309 | |
d11ecd3d JK |
310 | block_mig_state.read_done--; |
311 | block_mig_state.transferred++; | |
312 | assert(block_mig_state.read_done >= 0); | |
c163b5ca | 313 | } |
c163b5ca | 314 | |
d11ecd3d JK |
315 | dprintf("%s Exit submitted %d read_done %d transferred %d\n", __FUNCTION__, |
316 | block_mig_state.submitted, block_mig_state.read_done, | |
317 | block_mig_state.transferred); | |
c163b5ca | 318 | } |
319 | ||
320 | static int is_stage2_completed(void) | |
321 | { | |
322 | BlkMigDevState *bmds; | |
a55eb92c | 323 | |
d11ecd3d | 324 | if (block_mig_state.submitted > 0) { |
c163b5ca | 325 | return 0; |
326 | } | |
a55eb92c | 327 | |
5e5328be | 328 | QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) { |
a55eb92c | 329 | if (bmds->bulk_completed == 0) { |
c163b5ca | 330 | return 0; |
331 | } | |
332 | } | |
a55eb92c | 333 | |
c163b5ca | 334 | return 1; |
335 | } | |
336 | ||
337 | static int block_save_live(QEMUFile *f, int stage, void *opaque) | |
338 | { | |
d11ecd3d JK |
339 | dprintf("Enter save live stage %d submitted %d transferred %d\n", |
340 | stage, block_mig_state.submitted, block_mig_state.transferred); | |
a55eb92c | 341 | |
d11ecd3d | 342 | if (block_mig_state.blk_enable != 1) { |
c163b5ca | 343 | /* no need to migrate storage */ |
a55eb92c | 344 | qemu_put_be64(f, BLK_MIG_FLAG_EOS); |
c163b5ca | 345 | return 1; |
346 | } | |
a55eb92c JK |
347 | |
348 | if (stage == 1) { | |
c163b5ca | 349 | init_blk_migration(f); |
a55eb92c | 350 | |
c163b5ca | 351 | /* start track dirty blocks */ |
352 | set_dirty_tracking(1); | |
c163b5ca | 353 | } |
354 | ||
355 | flush_blks(f); | |
a55eb92c | 356 | |
c163b5ca | 357 | /* control the rate of transfer */ |
d11ecd3d JK |
358 | while ((block_mig_state.submitted + |
359 | block_mig_state.read_done) * BLOCK_SIZE < | |
a55eb92c JK |
360 | qemu_file_get_rate_limit(f)) { |
361 | if (blk_mig_save_bulked_block(f, 1) == 0) { | |
362 | /* no more bulk blocks for now */ | |
c163b5ca | 363 | break; |
a55eb92c | 364 | } |
c163b5ca | 365 | } |
a55eb92c | 366 | |
c163b5ca | 367 | flush_blks(f); |
a55eb92c JK |
368 | |
369 | if (stage == 3) { | |
370 | while (blk_mig_save_bulked_block(f, 0) != 0) { | |
371 | /* empty */ | |
372 | } | |
373 | ||
c163b5ca | 374 | blk_mig_save_dirty_blocks(f); |
a55eb92c | 375 | |
c163b5ca | 376 | /* stop track dirty blocks */ |
a55eb92c JK |
377 | set_dirty_tracking(0); |
378 | ||
379 | printf("\nBlock migration completed\n"); | |
c163b5ca | 380 | } |
a55eb92c JK |
381 | |
382 | qemu_put_be64(f, BLK_MIG_FLAG_EOS); | |
383 | ||
c163b5ca | 384 | return ((stage == 2) && is_stage2_completed()); |
385 | } | |
386 | ||
387 | static int block_load(QEMUFile *f, void *opaque, int version_id) | |
388 | { | |
389 | int len, flags; | |
390 | char device_name[256]; | |
391 | int64_t addr; | |
392 | BlockDriverState *bs; | |
393 | uint8_t *buf; | |
a55eb92c | 394 | |
c163b5ca | 395 | do { |
c163b5ca | 396 | addr = qemu_get_be64(f); |
a55eb92c | 397 | |
6ea44308 JK |
398 | flags = addr & ~BDRV_SECTOR_MASK; |
399 | addr >>= BDRV_SECTOR_BITS; | |
a55eb92c JK |
400 | |
401 | if (flags & BLK_MIG_FLAG_DEVICE_BLOCK) { | |
c163b5ca | 402 | /* get device name */ |
403 | len = qemu_get_byte(f); | |
a55eb92c | 404 | |
c163b5ca | 405 | qemu_get_buffer(f, (uint8_t *)device_name, len); |
406 | device_name[len] = '\0'; | |
a55eb92c | 407 | |
c163b5ca | 408 | bs = bdrv_find(device_name); |
a55eb92c | 409 | |
575a58d7 JK |
410 | buf = qemu_malloc(BLOCK_SIZE); |
411 | ||
a55eb92c JK |
412 | qemu_get_buffer(f, buf, BLOCK_SIZE); |
413 | if (bs != NULL) { | |
6ea44308 | 414 | bdrv_write(bs, addr, buf, BDRV_SECTORS_PER_DIRTY_CHUNK); |
c163b5ca | 415 | } else { |
416 | printf("Error unknown block device %s\n", device_name); | |
a55eb92c | 417 | /* FIXME: add error handling */ |
c163b5ca | 418 | } |
575a58d7 JK |
419 | |
420 | qemu_free(buf); | |
a55eb92c | 421 | } else if (!(flags & BLK_MIG_FLAG_EOS)) { |
c163b5ca | 422 | printf("Unknown flags\n"); |
a55eb92c | 423 | /* FIXME: add error handling */ |
c163b5ca | 424 | } |
a55eb92c JK |
425 | } while (!(flags & BLK_MIG_FLAG_EOS)); |
426 | ||
c163b5ca | 427 | return 0; |
428 | } | |
429 | ||
430 | static void block_set_params(int blk_enable, int shared_base, void *opaque) | |
431 | { | |
d11ecd3d JK |
432 | block_mig_state.blk_enable = blk_enable; |
433 | block_mig_state.shared_base = shared_base; | |
a55eb92c | 434 | |
c163b5ca | 435 | /* shared base means that blk_enable = 1 */ |
d11ecd3d | 436 | block_mig_state.blk_enable |= shared_base; |
c163b5ca | 437 | } |
438 | ||
c163b5ca | 439 | void blk_mig_init(void) |
a55eb92c | 440 | { |
5e5328be JK |
441 | QSIMPLEQ_INIT(&block_mig_state.bmds_list); |
442 | QSIMPLEQ_INIT(&block_mig_state.blk_list); | |
443 | ||
a55eb92c | 444 | register_savevm_live("block", 0, 1, block_set_params, block_save_live, |
d11ecd3d | 445 | NULL, block_load, &block_mig_state); |
c163b5ca | 446 | } |