coroutine: add test-coroutine --benchmark-lifecycle
[qemu/stefanha.git] / block-migration.c
blob0936c7d5ea347de19d37afe4ae7d9956381bc6d7
1 /*
2 * QEMU live block migration
4 * Copyright IBM, Corp. 2009
6 * Authors:
7 * Liran Schour <lirans@il.ibm.com>
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
14 #include "qemu-common.h"
15 #include "block_int.h"
16 #include "hw/hw.h"
17 #include "qemu-queue.h"
18 #include "qemu-timer.h"
19 #include "monitor.h"
20 #include "block-migration.h"
21 #include "migration.h"
22 #include "blockdev.h"
23 #include <assert.h>
25 #define BLOCK_SIZE (BDRV_SECTORS_PER_DIRTY_CHUNK << BDRV_SECTOR_BITS)
27 #define BLK_MIG_FLAG_DEVICE_BLOCK 0x01
28 #define BLK_MIG_FLAG_EOS 0x02
29 #define BLK_MIG_FLAG_PROGRESS 0x04
31 #define MAX_IS_ALLOCATED_SEARCH 65536
33 //#define DEBUG_BLK_MIGRATION
35 #ifdef DEBUG_BLK_MIGRATION
36 #define DPRINTF(fmt, ...) \
37 do { printf("blk_migration: " fmt, ## __VA_ARGS__); } while (0)
38 #else
39 #define DPRINTF(fmt, ...) \
40 do { } while (0)
41 #endif
43 typedef struct BlkMigDevState {
44 BlockDriverState *bs;
45 int bulk_completed;
46 int shared_base;
47 int64_t cur_sector;
48 int64_t cur_dirty;
49 int64_t completed_sectors;
50 int64_t total_sectors;
51 int64_t dirty;
52 QSIMPLEQ_ENTRY(BlkMigDevState) entry;
53 unsigned long *aio_bitmap;
54 } BlkMigDevState;
56 typedef struct BlkMigBlock {
57 uint8_t *buf;
58 BlkMigDevState *bmds;
59 int64_t sector;
60 int nr_sectors;
61 struct iovec iov;
62 QEMUIOVector qiov;
63 BlockDriverAIOCB *aiocb;
64 int ret;
65 QSIMPLEQ_ENTRY(BlkMigBlock) entry;
66 } BlkMigBlock;
68 typedef struct BlkMigState {
69 int blk_enable;
70 int shared_base;
71 QSIMPLEQ_HEAD(bmds_list, BlkMigDevState) bmds_list;
72 QSIMPLEQ_HEAD(blk_list, BlkMigBlock) blk_list;
73 int submitted;
74 int read_done;
75 int transferred;
76 int64_t total_sector_sum;
77 int prev_progress;
78 int bulk_completed;
79 long double total_time;
80 long double prev_time_offset;
81 int reads;
82 } BlkMigState;
84 static BlkMigState block_mig_state;
86 static void blk_send(QEMUFile *f, BlkMigBlock * blk)
88 int len;
90 /* sector number and flags */
91 qemu_put_be64(f, (blk->sector << BDRV_SECTOR_BITS)
92 | BLK_MIG_FLAG_DEVICE_BLOCK);
94 /* device name */
95 len = strlen(blk->bmds->bs->device_name);
96 qemu_put_byte(f, len);
97 qemu_put_buffer(f, (uint8_t *)blk->bmds->bs->device_name, len);
99 qemu_put_buffer(f, blk->buf, BLOCK_SIZE);
102 int blk_mig_active(void)
104 return !QSIMPLEQ_EMPTY(&block_mig_state.bmds_list);
107 uint64_t blk_mig_bytes_transferred(void)
109 BlkMigDevState *bmds;
110 uint64_t sum = 0;
112 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
113 sum += bmds->completed_sectors;
115 return sum << BDRV_SECTOR_BITS;
118 uint64_t blk_mig_bytes_remaining(void)
120 return blk_mig_bytes_total() - blk_mig_bytes_transferred();
123 uint64_t blk_mig_bytes_total(void)
125 BlkMigDevState *bmds;
126 uint64_t sum = 0;
128 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
129 sum += bmds->total_sectors;
131 return sum << BDRV_SECTOR_BITS;
134 static inline long double compute_read_bwidth(void)
136 assert(block_mig_state.total_time != 0);
137 return (block_mig_state.reads / block_mig_state.total_time) * BLOCK_SIZE;
140 static int bmds_aio_inflight(BlkMigDevState *bmds, int64_t sector)
142 int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
144 if ((sector << BDRV_SECTOR_BITS) < bdrv_getlength(bmds->bs)) {
145 return !!(bmds->aio_bitmap[chunk / (sizeof(unsigned long) * 8)] &
146 (1UL << (chunk % (sizeof(unsigned long) * 8))));
147 } else {
148 return 0;
152 static void bmds_set_aio_inflight(BlkMigDevState *bmds, int64_t sector_num,
153 int nb_sectors, int set)
155 int64_t start, end;
156 unsigned long val, idx, bit;
158 start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
159 end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
161 for (; start <= end; start++) {
162 idx = start / (sizeof(unsigned long) * 8);
163 bit = start % (sizeof(unsigned long) * 8);
164 val = bmds->aio_bitmap[idx];
165 if (set) {
166 val |= 1UL << bit;
167 } else {
168 val &= ~(1UL << bit);
170 bmds->aio_bitmap[idx] = val;
174 static void alloc_aio_bitmap(BlkMigDevState *bmds)
176 BlockDriverState *bs = bmds->bs;
177 int64_t bitmap_size;
179 bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
180 BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
181 bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
183 bmds->aio_bitmap = qemu_mallocz(bitmap_size);
186 static void blk_mig_read_cb(void *opaque, int ret)
188 long double curr_time = qemu_get_clock_ns(rt_clock);
189 BlkMigBlock *blk = opaque;
191 blk->ret = ret;
193 block_mig_state.reads++;
194 block_mig_state.total_time += (curr_time - block_mig_state.prev_time_offset);
195 block_mig_state.prev_time_offset = curr_time;
197 QSIMPLEQ_INSERT_TAIL(&block_mig_state.blk_list, blk, entry);
198 bmds_set_aio_inflight(blk->bmds, blk->sector, blk->nr_sectors, 0);
200 block_mig_state.submitted--;
201 block_mig_state.read_done++;
202 assert(block_mig_state.submitted >= 0);
205 static int mig_save_device_bulk(Monitor *mon, QEMUFile *f,
206 BlkMigDevState *bmds)
208 int64_t total_sectors = bmds->total_sectors;
209 int64_t cur_sector = bmds->cur_sector;
210 BlockDriverState *bs = bmds->bs;
211 BlkMigBlock *blk;
212 int nr_sectors;
214 if (bmds->shared_base) {
215 while (cur_sector < total_sectors &&
216 !bdrv_is_allocated(bs, cur_sector, MAX_IS_ALLOCATED_SEARCH,
217 &nr_sectors)) {
218 cur_sector += nr_sectors;
222 if (cur_sector >= total_sectors) {
223 bmds->cur_sector = bmds->completed_sectors = total_sectors;
224 return 1;
227 bmds->completed_sectors = cur_sector;
229 cur_sector &= ~((int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK - 1);
231 /* we are going to transfer a full block even if it is not allocated */
232 nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
234 if (total_sectors - cur_sector < BDRV_SECTORS_PER_DIRTY_CHUNK) {
235 nr_sectors = total_sectors - cur_sector;
238 blk = qemu_malloc(sizeof(BlkMigBlock));
239 blk->buf = qemu_malloc(BLOCK_SIZE);
240 blk->bmds = bmds;
241 blk->sector = cur_sector;
242 blk->nr_sectors = nr_sectors;
244 blk->iov.iov_base = blk->buf;
245 blk->iov.iov_len = nr_sectors * BDRV_SECTOR_SIZE;
246 qemu_iovec_init_external(&blk->qiov, &blk->iov, 1);
248 if (block_mig_state.submitted == 0) {
249 block_mig_state.prev_time_offset = qemu_get_clock_ns(rt_clock);
252 blk->aiocb = bdrv_aio_readv(bs, cur_sector, &blk->qiov,
253 nr_sectors, blk_mig_read_cb, blk);
254 if (!blk->aiocb) {
255 goto error;
257 block_mig_state.submitted++;
259 bdrv_reset_dirty(bs, cur_sector, nr_sectors);
260 bmds->cur_sector = cur_sector + nr_sectors;
262 return (bmds->cur_sector >= total_sectors);
264 error:
265 monitor_printf(mon, "Error reading sector %" PRId64 "\n", cur_sector);
266 qemu_file_set_error(f);
267 qemu_free(blk->buf);
268 qemu_free(blk);
269 return 0;
272 static void set_dirty_tracking(int enable)
274 BlkMigDevState *bmds;
276 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
277 bdrv_set_dirty_tracking(bmds->bs, enable);
281 static void init_blk_migration_it(void *opaque, BlockDriverState *bs)
283 Monitor *mon = opaque;
284 BlkMigDevState *bmds;
285 int64_t sectors;
287 if (!bdrv_is_read_only(bs)) {
288 sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
289 if (sectors <= 0) {
290 return;
293 bmds = qemu_mallocz(sizeof(BlkMigDevState));
294 bmds->bs = bs;
295 bmds->bulk_completed = 0;
296 bmds->total_sectors = sectors;
297 bmds->completed_sectors = 0;
298 bmds->shared_base = block_mig_state.shared_base;
299 alloc_aio_bitmap(bmds);
300 drive_get_ref(drive_get_by_blockdev(bs));
301 bdrv_set_in_use(bs, 1);
303 block_mig_state.total_sector_sum += sectors;
305 if (bmds->shared_base) {
306 monitor_printf(mon, "Start migration for %s with shared base "
307 "image\n",
308 bs->device_name);
309 } else {
310 monitor_printf(mon, "Start full migration for %s\n",
311 bs->device_name);
314 QSIMPLEQ_INSERT_TAIL(&block_mig_state.bmds_list, bmds, entry);
318 static void init_blk_migration(Monitor *mon, QEMUFile *f)
320 block_mig_state.submitted = 0;
321 block_mig_state.read_done = 0;
322 block_mig_state.transferred = 0;
323 block_mig_state.total_sector_sum = 0;
324 block_mig_state.prev_progress = -1;
325 block_mig_state.bulk_completed = 0;
326 block_mig_state.total_time = 0;
327 block_mig_state.reads = 0;
329 bdrv_iterate(init_blk_migration_it, mon);
332 static int blk_mig_save_bulked_block(Monitor *mon, QEMUFile *f)
334 int64_t completed_sector_sum = 0;
335 BlkMigDevState *bmds;
336 int progress;
337 int ret = 0;
339 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
340 if (bmds->bulk_completed == 0) {
341 if (mig_save_device_bulk(mon, f, bmds) == 1) {
342 /* completed bulk section for this device */
343 bmds->bulk_completed = 1;
345 completed_sector_sum += bmds->completed_sectors;
346 ret = 1;
347 break;
348 } else {
349 completed_sector_sum += bmds->completed_sectors;
353 if (block_mig_state.total_sector_sum != 0) {
354 progress = completed_sector_sum * 100 /
355 block_mig_state.total_sector_sum;
356 } else {
357 progress = 100;
359 if (progress != block_mig_state.prev_progress) {
360 block_mig_state.prev_progress = progress;
361 qemu_put_be64(f, (progress << BDRV_SECTOR_BITS)
362 | BLK_MIG_FLAG_PROGRESS);
363 monitor_printf(mon, "Completed %d %%\r", progress);
364 monitor_flush(mon);
367 return ret;
370 static void blk_mig_reset_dirty_cursor(void)
372 BlkMigDevState *bmds;
374 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
375 bmds->cur_dirty = 0;
379 static int mig_save_device_dirty(Monitor *mon, QEMUFile *f,
380 BlkMigDevState *bmds, int is_async)
382 BlkMigBlock *blk;
383 int64_t total_sectors = bmds->total_sectors;
384 int64_t sector;
385 int nr_sectors;
387 for (sector = bmds->cur_dirty; sector < bmds->total_sectors;) {
388 if (bmds_aio_inflight(bmds, sector)) {
389 qemu_aio_flush();
391 if (bdrv_get_dirty(bmds->bs, sector)) {
393 if (total_sectors - sector < BDRV_SECTORS_PER_DIRTY_CHUNK) {
394 nr_sectors = total_sectors - sector;
395 } else {
396 nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
398 blk = qemu_malloc(sizeof(BlkMigBlock));
399 blk->buf = qemu_malloc(BLOCK_SIZE);
400 blk->bmds = bmds;
401 blk->sector = sector;
402 blk->nr_sectors = nr_sectors;
404 if (is_async) {
405 blk->iov.iov_base = blk->buf;
406 blk->iov.iov_len = nr_sectors * BDRV_SECTOR_SIZE;
407 qemu_iovec_init_external(&blk->qiov, &blk->iov, 1);
409 if (block_mig_state.submitted == 0) {
410 block_mig_state.prev_time_offset = qemu_get_clock_ns(rt_clock);
413 blk->aiocb = bdrv_aio_readv(bmds->bs, sector, &blk->qiov,
414 nr_sectors, blk_mig_read_cb, blk);
415 if (!blk->aiocb) {
416 goto error;
418 block_mig_state.submitted++;
419 bmds_set_aio_inflight(bmds, sector, nr_sectors, 1);
420 } else {
421 if (bdrv_read(bmds->bs, sector, blk->buf,
422 nr_sectors) < 0) {
423 goto error;
425 blk_send(f, blk);
427 qemu_free(blk->buf);
428 qemu_free(blk);
431 bdrv_reset_dirty(bmds->bs, sector, nr_sectors);
432 break;
434 sector += BDRV_SECTORS_PER_DIRTY_CHUNK;
435 bmds->cur_dirty = sector;
438 return (bmds->cur_dirty >= bmds->total_sectors);
440 error:
441 monitor_printf(mon, "Error reading sector %" PRId64 "\n", sector);
442 qemu_file_set_error(f);
443 qemu_free(blk->buf);
444 qemu_free(blk);
445 return 0;
448 static int blk_mig_save_dirty_block(Monitor *mon, QEMUFile *f, int is_async)
450 BlkMigDevState *bmds;
451 int ret = 0;
453 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
454 if (mig_save_device_dirty(mon, f, bmds, is_async) == 0) {
455 ret = 1;
456 break;
460 return ret;
463 static void flush_blks(QEMUFile* f)
465 BlkMigBlock *blk;
467 DPRINTF("%s Enter submitted %d read_done %d transferred %d\n",
468 __FUNCTION__, block_mig_state.submitted, block_mig_state.read_done,
469 block_mig_state.transferred);
471 while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) {
472 if (qemu_file_rate_limit(f)) {
473 break;
475 if (blk->ret < 0) {
476 qemu_file_set_error(f);
477 break;
479 blk_send(f, blk);
481 QSIMPLEQ_REMOVE_HEAD(&block_mig_state.blk_list, entry);
482 qemu_free(blk->buf);
483 qemu_free(blk);
485 block_mig_state.read_done--;
486 block_mig_state.transferred++;
487 assert(block_mig_state.read_done >= 0);
490 DPRINTF("%s Exit submitted %d read_done %d transferred %d\n", __FUNCTION__,
491 block_mig_state.submitted, block_mig_state.read_done,
492 block_mig_state.transferred);
495 static int64_t get_remaining_dirty(void)
497 BlkMigDevState *bmds;
498 int64_t dirty = 0;
500 QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
501 dirty += bdrv_get_dirty_count(bmds->bs);
504 return dirty * BLOCK_SIZE;
507 static int is_stage2_completed(void)
509 int64_t remaining_dirty;
510 long double bwidth;
512 if (block_mig_state.bulk_completed == 1) {
514 remaining_dirty = get_remaining_dirty();
515 if (remaining_dirty == 0) {
516 return 1;
519 bwidth = compute_read_bwidth();
521 if ((remaining_dirty / bwidth) <=
522 migrate_max_downtime()) {
523 /* finish stage2 because we think that we can finish remaing work
524 below max_downtime */
526 return 1;
530 return 0;
533 static void blk_mig_cleanup(Monitor *mon)
535 BlkMigDevState *bmds;
536 BlkMigBlock *blk;
538 set_dirty_tracking(0);
540 while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != NULL) {
541 QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry);
542 bdrv_set_in_use(bmds->bs, 0);
543 drive_put_ref(drive_get_by_blockdev(bmds->bs));
544 qemu_free(bmds->aio_bitmap);
545 qemu_free(bmds);
548 while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) {
549 QSIMPLEQ_REMOVE_HEAD(&block_mig_state.blk_list, entry);
550 qemu_free(blk->buf);
551 qemu_free(blk);
554 monitor_printf(mon, "\n");
557 static int block_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
559 DPRINTF("Enter save live stage %d submitted %d transferred %d\n",
560 stage, block_mig_state.submitted, block_mig_state.transferred);
562 if (stage < 0) {
563 blk_mig_cleanup(mon);
564 return 0;
567 if (block_mig_state.blk_enable != 1) {
568 /* no need to migrate storage */
569 qemu_put_be64(f, BLK_MIG_FLAG_EOS);
570 return 1;
573 if (stage == 1) {
574 init_blk_migration(mon, f);
576 /* start track dirty blocks */
577 set_dirty_tracking(1);
580 flush_blks(f);
582 if (qemu_file_has_error(f)) {
583 blk_mig_cleanup(mon);
584 return 0;
587 blk_mig_reset_dirty_cursor();
589 if (stage == 2) {
590 /* control the rate of transfer */
591 while ((block_mig_state.submitted +
592 block_mig_state.read_done) * BLOCK_SIZE <
593 qemu_file_get_rate_limit(f)) {
594 if (block_mig_state.bulk_completed == 0) {
595 /* first finish the bulk phase */
596 if (blk_mig_save_bulked_block(mon, f) == 0) {
597 /* finished saving bulk on all devices */
598 block_mig_state.bulk_completed = 1;
600 } else {
601 if (blk_mig_save_dirty_block(mon, f, 1) == 0) {
602 /* no more dirty blocks */
603 break;
608 flush_blks(f);
610 if (qemu_file_has_error(f)) {
611 blk_mig_cleanup(mon);
612 return 0;
616 if (stage == 3) {
617 /* we know for sure that save bulk is completed and
618 all async read completed */
619 assert(block_mig_state.submitted == 0);
621 while (blk_mig_save_dirty_block(mon, f, 0) != 0);
622 blk_mig_cleanup(mon);
624 /* report completion */
625 qemu_put_be64(f, (100 << BDRV_SECTOR_BITS) | BLK_MIG_FLAG_PROGRESS);
627 if (qemu_file_has_error(f)) {
628 return 0;
631 monitor_printf(mon, "Block migration completed\n");
634 qemu_put_be64(f, BLK_MIG_FLAG_EOS);
636 return ((stage == 2) && is_stage2_completed());
639 static int block_load(QEMUFile *f, void *opaque, int version_id)
641 static int banner_printed;
642 int len, flags;
643 char device_name[256];
644 int64_t addr;
645 BlockDriverState *bs, *bs_prev = NULL;
646 uint8_t *buf;
647 int64_t total_sectors = 0;
648 int nr_sectors;
650 do {
651 addr = qemu_get_be64(f);
653 flags = addr & ~BDRV_SECTOR_MASK;
654 addr >>= BDRV_SECTOR_BITS;
656 if (flags & BLK_MIG_FLAG_DEVICE_BLOCK) {
657 int ret;
658 /* get device name */
659 len = qemu_get_byte(f);
660 qemu_get_buffer(f, (uint8_t *)device_name, len);
661 device_name[len] = '\0';
663 bs = bdrv_find(device_name);
664 if (!bs) {
665 fprintf(stderr, "Error unknown block device %s\n",
666 device_name);
667 return -EINVAL;
670 if (bs != bs_prev) {
671 bs_prev = bs;
672 total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
673 if (total_sectors <= 0) {
674 error_report("Error getting length of block device %s",
675 device_name);
676 return -EINVAL;
680 if (total_sectors - addr < BDRV_SECTORS_PER_DIRTY_CHUNK) {
681 nr_sectors = total_sectors - addr;
682 } else {
683 nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
686 buf = qemu_malloc(BLOCK_SIZE);
688 qemu_get_buffer(f, buf, BLOCK_SIZE);
689 ret = bdrv_write(bs, addr, buf, nr_sectors);
691 qemu_free(buf);
692 if (ret < 0) {
693 return ret;
695 } else if (flags & BLK_MIG_FLAG_PROGRESS) {
696 if (!banner_printed) {
697 printf("Receiving block device images\n");
698 banner_printed = 1;
700 printf("Completed %d %%%c", (int)addr,
701 (addr == 100) ? '\n' : '\r');
702 fflush(stdout);
703 } else if (!(flags & BLK_MIG_FLAG_EOS)) {
704 fprintf(stderr, "Unknown flags\n");
705 return -EINVAL;
707 if (qemu_file_has_error(f)) {
708 return -EIO;
710 } while (!(flags & BLK_MIG_FLAG_EOS));
712 return 0;
715 static void block_set_params(int blk_enable, int shared_base, void *opaque)
717 block_mig_state.blk_enable = blk_enable;
718 block_mig_state.shared_base = shared_base;
720 /* shared base means that blk_enable = 1 */
721 block_mig_state.blk_enable |= shared_base;
724 void blk_mig_init(void)
726 QSIMPLEQ_INIT(&block_mig_state.bmds_list);
727 QSIMPLEQ_INIT(&block_mig_state.blk_list);
729 register_savevm_live(NULL, "block", 0, 1, block_set_params,
730 block_save_live, NULL, block_load, &block_mig_state);