2 * QEMU live block migration
4 * Copyright IBM, Corp. 2009
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.
12 * Contributions after 2012-01-13 are licensed under the terms of the
13 * GNU GPL, version 2 or (at your option) any later version.
16 #include "qemu/osdep.h"
17 #include "qapi/error.h"
18 #include "qemu/error-report.h"
19 #include "qemu/cutils.h"
20 #include "qemu/queue.h"
22 #include "migration/misc.h"
23 #include "migration.h"
24 #include "migration/register.h"
25 #include "qemu-file.h"
26 #include "migration/vmstate.h"
27 #include "sysemu/block-backend.h"
29 #define BLOCK_SIZE (1 << 20)
30 #define BDRV_SECTORS_PER_DIRTY_CHUNK (BLOCK_SIZE >> BDRV_SECTOR_BITS)
32 #define BLK_MIG_FLAG_DEVICE_BLOCK 0x01
33 #define BLK_MIG_FLAG_EOS 0x02
34 #define BLK_MIG_FLAG_PROGRESS 0x04
35 #define BLK_MIG_FLAG_ZERO_BLOCK 0x08
37 #define MAX_IS_ALLOCATED_SEARCH 65536
39 #define MAX_INFLIGHT_IO 512
41 //#define DEBUG_BLK_MIGRATION
43 #ifdef DEBUG_BLK_MIGRATION
44 #define DPRINTF(fmt, ...) \
45 do { printf("blk_migration: " fmt, ## __VA_ARGS__); } while (0)
47 #define DPRINTF(fmt, ...) \
51 typedef struct BlkMigDevState
{
52 /* Written during setup phase. Can be read without a lock. */
56 int64_t total_sectors
;
57 QSIMPLEQ_ENTRY(BlkMigDevState
) entry
;
60 /* Only used by migration thread. Does not need a lock. */
65 /* Data in the aio_bitmap is protected by block migration lock.
66 * Allocation and free happen during setup and cleanup respectively.
68 unsigned long *aio_bitmap
;
70 /* Protected by block migration lock. */
71 int64_t completed_sectors
;
73 /* During migration this is protected by iothread lock / AioContext.
74 * Allocation and free happen during setup and cleanup respectively.
76 BdrvDirtyBitmap
*dirty_bitmap
;
79 typedef struct BlkMigBlock
{
80 /* Only used by migration thread. */
89 /* Protected by block migration lock. */
91 QSIMPLEQ_ENTRY(BlkMigBlock
) entry
;
94 typedef struct BlkMigState
{
95 QSIMPLEQ_HEAD(bmds_list
, BlkMigDevState
) bmds_list
;
96 int64_t total_sector_sum
;
99 /* Protected by lock. */
100 QSIMPLEQ_HEAD(blk_list
, BlkMigBlock
) blk_list
;
104 /* Only used by migration thread. Does not need a lock. */
109 /* Lock must be taken _inside_ the iothread lock and any AioContexts. */
113 static BlkMigState block_mig_state
;
115 static void blk_mig_lock(void)
117 qemu_mutex_lock(&block_mig_state
.lock
);
120 static void blk_mig_unlock(void)
122 qemu_mutex_unlock(&block_mig_state
.lock
);
125 /* Must run outside of the iothread lock during the bulk phase,
126 * or the VM will stall.
129 static void blk_send(QEMUFile
*f
, BlkMigBlock
* blk
)
132 uint64_t flags
= BLK_MIG_FLAG_DEVICE_BLOCK
;
134 if (block_mig_state
.zero_blocks
&&
135 buffer_is_zero(blk
->buf
, BLOCK_SIZE
)) {
136 flags
|= BLK_MIG_FLAG_ZERO_BLOCK
;
139 /* sector number and flags */
140 qemu_put_be64(f
, (blk
->sector
<< BDRV_SECTOR_BITS
)
144 len
= strlen(blk
->bmds
->blk_name
);
145 qemu_put_byte(f
, len
);
146 qemu_put_buffer(f
, (uint8_t *) blk
->bmds
->blk_name
, len
);
148 /* if a block is zero we need to flush here since the network
149 * bandwidth is now a lot higher than the storage device bandwidth.
150 * thus if we queue zero blocks we slow down the migration */
151 if (flags
& BLK_MIG_FLAG_ZERO_BLOCK
) {
156 qemu_put_buffer(f
, blk
->buf
, BLOCK_SIZE
);
159 int blk_mig_active(void)
161 return !QSIMPLEQ_EMPTY(&block_mig_state
.bmds_list
);
164 uint64_t blk_mig_bytes_transferred(void)
166 BlkMigDevState
*bmds
;
170 QSIMPLEQ_FOREACH(bmds
, &block_mig_state
.bmds_list
, entry
) {
171 sum
+= bmds
->completed_sectors
;
174 return sum
<< BDRV_SECTOR_BITS
;
177 uint64_t blk_mig_bytes_remaining(void)
179 return blk_mig_bytes_total() - blk_mig_bytes_transferred();
182 uint64_t blk_mig_bytes_total(void)
184 BlkMigDevState
*bmds
;
187 QSIMPLEQ_FOREACH(bmds
, &block_mig_state
.bmds_list
, entry
) {
188 sum
+= bmds
->total_sectors
;
190 return sum
<< BDRV_SECTOR_BITS
;
194 /* Called with migration lock held. */
196 static int bmds_aio_inflight(BlkMigDevState
*bmds
, int64_t sector
)
198 int64_t chunk
= sector
/ (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK
;
200 if (sector
< blk_nb_sectors(bmds
->blk
)) {
201 return !!(bmds
->aio_bitmap
[chunk
/ (sizeof(unsigned long) * 8)] &
202 (1UL << (chunk
% (sizeof(unsigned long) * 8))));
208 /* Called with migration lock held. */
210 static void bmds_set_aio_inflight(BlkMigDevState
*bmds
, int64_t sector_num
,
211 int nb_sectors
, int set
)
214 unsigned long val
, idx
, bit
;
216 start
= sector_num
/ BDRV_SECTORS_PER_DIRTY_CHUNK
;
217 end
= (sector_num
+ nb_sectors
- 1) / BDRV_SECTORS_PER_DIRTY_CHUNK
;
219 for (; start
<= end
; start
++) {
220 idx
= start
/ (sizeof(unsigned long) * 8);
221 bit
= start
% (sizeof(unsigned long) * 8);
222 val
= bmds
->aio_bitmap
[idx
];
226 val
&= ~(1UL << bit
);
228 bmds
->aio_bitmap
[idx
] = val
;
232 static void alloc_aio_bitmap(BlkMigDevState
*bmds
)
234 BlockBackend
*bb
= bmds
->blk
;
237 bitmap_size
= blk_nb_sectors(bb
) + BDRV_SECTORS_PER_DIRTY_CHUNK
* 8 - 1;
238 bitmap_size
/= BDRV_SECTORS_PER_DIRTY_CHUNK
* 8;
240 bmds
->aio_bitmap
= g_malloc0(bitmap_size
);
243 /* Never hold migration lock when yielding to the main loop! */
245 static void blk_mig_read_cb(void *opaque
, int ret
)
247 BlkMigBlock
*blk
= opaque
;
252 QSIMPLEQ_INSERT_TAIL(&block_mig_state
.blk_list
, blk
, entry
);
253 bmds_set_aio_inflight(blk
->bmds
, blk
->sector
, blk
->nr_sectors
, 0);
255 block_mig_state
.submitted
--;
256 block_mig_state
.read_done
++;
257 assert(block_mig_state
.submitted
>= 0);
261 /* Called with no lock taken. */
263 static int mig_save_device_bulk(QEMUFile
*f
, BlkMigDevState
*bmds
)
265 int64_t total_sectors
= bmds
->total_sectors
;
266 int64_t cur_sector
= bmds
->cur_sector
;
267 BlockBackend
*bb
= bmds
->blk
;
271 if (bmds
->shared_base
) {
272 qemu_mutex_lock_iothread();
273 aio_context_acquire(blk_get_aio_context(bb
));
274 /* Skip unallocated sectors; intentionally treats failure as
275 * an allocated sector */
276 while (cur_sector
< total_sectors
&&
277 !bdrv_is_allocated(blk_bs(bb
), cur_sector
,
278 MAX_IS_ALLOCATED_SEARCH
, &nr_sectors
)) {
279 cur_sector
+= nr_sectors
;
281 aio_context_release(blk_get_aio_context(bb
));
282 qemu_mutex_unlock_iothread();
285 if (cur_sector
>= total_sectors
) {
286 bmds
->cur_sector
= bmds
->completed_sectors
= total_sectors
;
290 bmds
->completed_sectors
= cur_sector
;
292 cur_sector
&= ~((int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK
- 1);
294 /* we are going to transfer a full block even if it is not allocated */
295 nr_sectors
= BDRV_SECTORS_PER_DIRTY_CHUNK
;
297 if (total_sectors
- cur_sector
< BDRV_SECTORS_PER_DIRTY_CHUNK
) {
298 nr_sectors
= total_sectors
- cur_sector
;
301 blk
= g_new(BlkMigBlock
, 1);
302 blk
->buf
= g_malloc(BLOCK_SIZE
);
304 blk
->sector
= cur_sector
;
305 blk
->nr_sectors
= nr_sectors
;
307 blk
->iov
.iov_base
= blk
->buf
;
308 blk
->iov
.iov_len
= nr_sectors
* BDRV_SECTOR_SIZE
;
309 qemu_iovec_init_external(&blk
->qiov
, &blk
->iov
, 1);
312 block_mig_state
.submitted
++;
315 /* We do not know if bs is under the main thread (and thus does
316 * not acquire the AioContext when doing AIO) or rather under
317 * dataplane. Thus acquire both the iothread mutex and the
320 * This is ugly and will disappear when we make bdrv_* thread-safe,
321 * without the need to acquire the AioContext.
323 qemu_mutex_lock_iothread();
324 aio_context_acquire(blk_get_aio_context(bmds
->blk
));
325 blk
->aiocb
= blk_aio_preadv(bb
, cur_sector
* BDRV_SECTOR_SIZE
, &blk
->qiov
,
326 0, blk_mig_read_cb
, blk
);
328 bdrv_reset_dirty_bitmap(bmds
->dirty_bitmap
, cur_sector
, nr_sectors
);
329 aio_context_release(blk_get_aio_context(bmds
->blk
));
330 qemu_mutex_unlock_iothread();
332 bmds
->cur_sector
= cur_sector
+ nr_sectors
;
333 return (bmds
->cur_sector
>= total_sectors
);
336 /* Called with iothread lock taken. */
338 static int set_dirty_tracking(void)
340 BlkMigDevState
*bmds
;
343 QSIMPLEQ_FOREACH(bmds
, &block_mig_state
.bmds_list
, entry
) {
344 aio_context_acquire(blk_get_aio_context(bmds
->blk
));
345 bmds
->dirty_bitmap
= bdrv_create_dirty_bitmap(blk_bs(bmds
->blk
),
346 BLOCK_SIZE
, NULL
, NULL
);
347 aio_context_release(blk_get_aio_context(bmds
->blk
));
348 if (!bmds
->dirty_bitmap
) {
356 QSIMPLEQ_FOREACH(bmds
, &block_mig_state
.bmds_list
, entry
) {
357 if (bmds
->dirty_bitmap
) {
358 aio_context_acquire(blk_get_aio_context(bmds
->blk
));
359 bdrv_release_dirty_bitmap(blk_bs(bmds
->blk
), bmds
->dirty_bitmap
);
360 aio_context_release(blk_get_aio_context(bmds
->blk
));
366 /* Called with iothread lock taken. */
368 static void unset_dirty_tracking(void)
370 BlkMigDevState
*bmds
;
372 QSIMPLEQ_FOREACH(bmds
, &block_mig_state
.bmds_list
, entry
) {
373 aio_context_acquire(blk_get_aio_context(bmds
->blk
));
374 bdrv_release_dirty_bitmap(blk_bs(bmds
->blk
), bmds
->dirty_bitmap
);
375 aio_context_release(blk_get_aio_context(bmds
->blk
));
379 static int init_blk_migration(QEMUFile
*f
)
381 BlockDriverState
*bs
;
382 BlkMigDevState
*bmds
;
387 BlkMigDevState
*bmds
;
388 BlockDriverState
*bs
;
390 Error
*local_err
= NULL
;
393 block_mig_state
.submitted
= 0;
394 block_mig_state
.read_done
= 0;
395 block_mig_state
.transferred
= 0;
396 block_mig_state
.total_sector_sum
= 0;
397 block_mig_state
.prev_progress
= -1;
398 block_mig_state
.bulk_completed
= 0;
399 block_mig_state
.zero_blocks
= migrate_zero_blocks();
401 for (bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
)) {
404 bmds_bs
= g_malloc0(num_bs
* sizeof(*bmds_bs
));
406 for (i
= 0, bs
= bdrv_first(&it
); bs
; bs
= bdrv_next(&it
), i
++) {
407 if (bdrv_is_read_only(bs
)) {
411 sectors
= bdrv_nb_sectors(bs
);
417 bmds
= g_new0(BlkMigDevState
, 1);
418 bmds
->blk
= blk_new(BLK_PERM_CONSISTENT_READ
, BLK_PERM_ALL
);
419 bmds
->blk_name
= g_strdup(bdrv_get_device_name(bs
));
420 bmds
->bulk_completed
= 0;
421 bmds
->total_sectors
= sectors
;
422 bmds
->completed_sectors
= 0;
423 bmds
->shared_base
= migrate_use_block_incremental();
426 bmds_bs
[i
].bmds
= bmds
;
429 block_mig_state
.total_sector_sum
+= sectors
;
431 if (bmds
->shared_base
) {
432 DPRINTF("Start migration for %s with shared base image\n",
433 bdrv_get_device_name(bs
));
435 DPRINTF("Start full migration for %s\n", bdrv_get_device_name(bs
));
438 QSIMPLEQ_INSERT_TAIL(&block_mig_state
.bmds_list
, bmds
, entry
);
441 /* Can only insert new BDSes now because doing so while iterating block
442 * devices may end up in a deadlock (iterating the new BDSes, too). */
443 for (i
= 0; i
< num_bs
; i
++) {
444 BlkMigDevState
*bmds
= bmds_bs
[i
].bmds
;
445 BlockDriverState
*bs
= bmds_bs
[i
].bs
;
448 ret
= blk_insert_bs(bmds
->blk
, bs
, &local_err
);
450 error_report_err(local_err
);
454 alloc_aio_bitmap(bmds
);
455 error_setg(&bmds
->blocker
, "block device is in use by migration");
456 bdrv_op_block_all(bs
, bmds
->blocker
);
466 /* Called with no lock taken. */
468 static int blk_mig_save_bulked_block(QEMUFile
*f
)
470 int64_t completed_sector_sum
= 0;
471 BlkMigDevState
*bmds
;
475 QSIMPLEQ_FOREACH(bmds
, &block_mig_state
.bmds_list
, entry
) {
476 if (bmds
->bulk_completed
== 0) {
477 if (mig_save_device_bulk(f
, bmds
) == 1) {
478 /* completed bulk section for this device */
479 bmds
->bulk_completed
= 1;
481 completed_sector_sum
+= bmds
->completed_sectors
;
485 completed_sector_sum
+= bmds
->completed_sectors
;
489 if (block_mig_state
.total_sector_sum
!= 0) {
490 progress
= completed_sector_sum
* 100 /
491 block_mig_state
.total_sector_sum
;
495 if (progress
!= block_mig_state
.prev_progress
) {
496 block_mig_state
.prev_progress
= progress
;
497 qemu_put_be64(f
, (progress
<< BDRV_SECTOR_BITS
)
498 | BLK_MIG_FLAG_PROGRESS
);
499 DPRINTF("Completed %d %%\r", progress
);
505 static void blk_mig_reset_dirty_cursor(void)
507 BlkMigDevState
*bmds
;
509 QSIMPLEQ_FOREACH(bmds
, &block_mig_state
.bmds_list
, entry
) {
514 /* Called with iothread lock and AioContext taken. */
516 static int mig_save_device_dirty(QEMUFile
*f
, BlkMigDevState
*bmds
,
520 BlockDriverState
*bs
= blk_bs(bmds
->blk
);
521 int64_t total_sectors
= bmds
->total_sectors
;
526 for (sector
= bmds
->cur_dirty
; sector
< bmds
->total_sectors
;) {
528 if (bmds_aio_inflight(bmds
, sector
)) {
530 blk_drain(bmds
->blk
);
534 if (bdrv_get_dirty(bs
, bmds
->dirty_bitmap
, sector
)) {
536 if (total_sectors
- sector
< BDRV_SECTORS_PER_DIRTY_CHUNK
) {
537 nr_sectors
= total_sectors
- sector
;
539 nr_sectors
= BDRV_SECTORS_PER_DIRTY_CHUNK
;
541 blk
= g_new(BlkMigBlock
, 1);
542 blk
->buf
= g_malloc(BLOCK_SIZE
);
544 blk
->sector
= sector
;
545 blk
->nr_sectors
= nr_sectors
;
548 blk
->iov
.iov_base
= blk
->buf
;
549 blk
->iov
.iov_len
= nr_sectors
* BDRV_SECTOR_SIZE
;
550 qemu_iovec_init_external(&blk
->qiov
, &blk
->iov
, 1);
552 blk
->aiocb
= blk_aio_preadv(bmds
->blk
,
553 sector
* BDRV_SECTOR_SIZE
,
554 &blk
->qiov
, 0, blk_mig_read_cb
,
558 block_mig_state
.submitted
++;
559 bmds_set_aio_inflight(bmds
, sector
, nr_sectors
, 1);
562 ret
= blk_pread(bmds
->blk
, sector
* BDRV_SECTOR_SIZE
, blk
->buf
,
563 nr_sectors
* BDRV_SECTOR_SIZE
);
573 bdrv_reset_dirty_bitmap(bmds
->dirty_bitmap
, sector
, nr_sectors
);
574 sector
+= nr_sectors
;
575 bmds
->cur_dirty
= sector
;
579 sector
+= BDRV_SECTORS_PER_DIRTY_CHUNK
;
580 bmds
->cur_dirty
= sector
;
583 return (bmds
->cur_dirty
>= bmds
->total_sectors
);
586 DPRINTF("Error reading sector %" PRId64
"\n", sector
);
592 /* Called with iothread lock taken.
595 * 0: too much data for max_downtime
596 * 1: few enough data for max_downtime
598 static int blk_mig_save_dirty_block(QEMUFile
*f
, int is_async
)
600 BlkMigDevState
*bmds
;
603 QSIMPLEQ_FOREACH(bmds
, &block_mig_state
.bmds_list
, entry
) {
604 aio_context_acquire(blk_get_aio_context(bmds
->blk
));
605 ret
= mig_save_device_dirty(f
, bmds
, is_async
);
606 aio_context_release(blk_get_aio_context(bmds
->blk
));
615 /* Called with no locks taken. */
617 static int flush_blks(QEMUFile
*f
)
622 DPRINTF("%s Enter submitted %d read_done %d transferred %d\n",
623 __FUNCTION__
, block_mig_state
.submitted
, block_mig_state
.read_done
,
624 block_mig_state
.transferred
);
627 while ((blk
= QSIMPLEQ_FIRST(&block_mig_state
.blk_list
)) != NULL
) {
628 if (qemu_file_rate_limit(f
)) {
636 QSIMPLEQ_REMOVE_HEAD(&block_mig_state
.blk_list
, entry
);
644 block_mig_state
.read_done
--;
645 block_mig_state
.transferred
++;
646 assert(block_mig_state
.read_done
>= 0);
650 DPRINTF("%s Exit submitted %d read_done %d transferred %d\n", __FUNCTION__
,
651 block_mig_state
.submitted
, block_mig_state
.read_done
,
652 block_mig_state
.transferred
);
656 /* Called with iothread lock taken. */
658 static int64_t get_remaining_dirty(void)
660 BlkMigDevState
*bmds
;
663 QSIMPLEQ_FOREACH(bmds
, &block_mig_state
.bmds_list
, entry
) {
664 aio_context_acquire(blk_get_aio_context(bmds
->blk
));
665 dirty
+= bdrv_get_dirty_count(bmds
->dirty_bitmap
);
666 aio_context_release(blk_get_aio_context(bmds
->blk
));
669 return dirty
<< BDRV_SECTOR_BITS
;
674 /* Called with iothread lock taken. */
675 static void block_migration_cleanup_bmds(void)
677 BlkMigDevState
*bmds
;
680 unset_dirty_tracking();
682 while ((bmds
= QSIMPLEQ_FIRST(&block_mig_state
.bmds_list
)) != NULL
) {
683 QSIMPLEQ_REMOVE_HEAD(&block_mig_state
.bmds_list
, entry
);
684 bdrv_op_unblock_all(blk_bs(bmds
->blk
), bmds
->blocker
);
685 error_free(bmds
->blocker
);
687 /* Save ctx, because bmds->blk can disappear during blk_unref. */
688 ctx
= blk_get_aio_context(bmds
->blk
);
689 aio_context_acquire(ctx
);
690 blk_unref(bmds
->blk
);
691 aio_context_release(ctx
);
693 g_free(bmds
->blk_name
);
694 g_free(bmds
->aio_bitmap
);
699 /* Called with iothread lock taken. */
700 static void block_migration_cleanup(void *opaque
)
706 block_migration_cleanup_bmds();
709 while ((blk
= QSIMPLEQ_FIRST(&block_mig_state
.blk_list
)) != NULL
) {
710 QSIMPLEQ_REMOVE_HEAD(&block_mig_state
.blk_list
, entry
);
717 static int block_save_setup(QEMUFile
*f
, void *opaque
)
721 DPRINTF("Enter save live setup submitted %d transferred %d\n",
722 block_mig_state
.submitted
, block_mig_state
.transferred
);
724 qemu_mutex_lock_iothread();
725 ret
= init_blk_migration(f
);
727 qemu_mutex_unlock_iothread();
731 /* start track dirty blocks */
732 ret
= set_dirty_tracking();
734 qemu_mutex_unlock_iothread();
741 blk_mig_reset_dirty_cursor();
742 qemu_put_be64(f
, BLK_MIG_FLAG_EOS
);
747 static int block_save_iterate(QEMUFile
*f
, void *opaque
)
750 int64_t last_ftell
= qemu_ftell(f
);
753 DPRINTF("Enter save live iterate submitted %d transferred %d\n",
754 block_mig_state
.submitted
, block_mig_state
.transferred
);
761 blk_mig_reset_dirty_cursor();
763 /* control the rate of transfer */
765 while ((block_mig_state
.submitted
+
766 block_mig_state
.read_done
) * BLOCK_SIZE
<
767 qemu_file_get_rate_limit(f
) &&
768 (block_mig_state
.submitted
+
769 block_mig_state
.read_done
) <
772 if (block_mig_state
.bulk_completed
== 0) {
773 /* first finish the bulk phase */
774 if (blk_mig_save_bulked_block(f
) == 0) {
775 /* finished saving bulk on all devices */
776 block_mig_state
.bulk_completed
= 1;
780 /* Always called with iothread lock taken for
781 * simplicity, block_save_complete also calls it.
783 qemu_mutex_lock_iothread();
784 ret
= blk_mig_save_dirty_block(f
, 1);
785 qemu_mutex_unlock_iothread();
792 /* no more dirty blocks */
803 qemu_put_be64(f
, BLK_MIG_FLAG_EOS
);
804 delta_ftell
= qemu_ftell(f
) - last_ftell
;
805 if (delta_ftell
> 0) {
807 } else if (delta_ftell
< 0) {
814 /* Called with iothread lock taken. */
816 static int block_save_complete(QEMUFile
*f
, void *opaque
)
820 DPRINTF("Enter save live complete submitted %d transferred %d\n",
821 block_mig_state
.submitted
, block_mig_state
.transferred
);
828 blk_mig_reset_dirty_cursor();
830 /* we know for sure that save bulk is completed and
831 all async read completed */
833 assert(block_mig_state
.submitted
== 0);
837 ret
= blk_mig_save_dirty_block(f
, 0);
843 /* report completion */
844 qemu_put_be64(f
, (100 << BDRV_SECTOR_BITS
) | BLK_MIG_FLAG_PROGRESS
);
846 DPRINTF("Block migration completed\n");
848 qemu_put_be64(f
, BLK_MIG_FLAG_EOS
);
850 /* Make sure that our BlockBackends are gone, so that the block driver
851 * nodes can be inactivated. */
852 block_migration_cleanup_bmds();
857 static void block_save_pending(QEMUFile
*f
, void *opaque
, uint64_t max_size
,
858 uint64_t *non_postcopiable_pending
,
859 uint64_t *postcopiable_pending
)
861 /* Estimate pending number of bytes to send */
864 qemu_mutex_lock_iothread();
865 pending
= get_remaining_dirty();
866 qemu_mutex_unlock_iothread();
869 pending
+= block_mig_state
.submitted
* BLOCK_SIZE
+
870 block_mig_state
.read_done
* BLOCK_SIZE
;
873 /* Report at least one block pending during bulk phase */
874 if (pending
<= max_size
&& !block_mig_state
.bulk_completed
) {
875 pending
= max_size
+ BLOCK_SIZE
;
878 DPRINTF("Enter save live pending %" PRIu64
"\n", pending
);
879 /* We don't do postcopy */
880 *non_postcopiable_pending
+= pending
;
883 static int block_load(QEMUFile
*f
, void *opaque
, int version_id
)
885 static int banner_printed
;
887 char device_name
[256];
889 BlockBackend
*blk
, *blk_prev
= NULL
;;
890 Error
*local_err
= NULL
;
892 int64_t total_sectors
= 0;
896 int cluster_size
= BLOCK_SIZE
;
899 addr
= qemu_get_be64(f
);
901 flags
= addr
& ~BDRV_SECTOR_MASK
;
902 addr
>>= BDRV_SECTOR_BITS
;
904 if (flags
& BLK_MIG_FLAG_DEVICE_BLOCK
) {
905 /* get device name */
906 len
= qemu_get_byte(f
);
907 qemu_get_buffer(f
, (uint8_t *)device_name
, len
);
908 device_name
[len
] = '\0';
910 blk
= blk_by_name(device_name
);
912 fprintf(stderr
, "Error unknown block device %s\n",
917 if (blk
!= blk_prev
) {
919 total_sectors
= blk_nb_sectors(blk
);
920 if (total_sectors
<= 0) {
921 error_report("Error getting length of block device %s",
926 blk_invalidate_cache(blk
, &local_err
);
928 error_report_err(local_err
);
932 ret
= bdrv_get_info(blk_bs(blk
), &bdi
);
933 if (ret
== 0 && bdi
.cluster_size
> 0 &&
934 bdi
.cluster_size
<= BLOCK_SIZE
&&
935 BLOCK_SIZE
% bdi
.cluster_size
== 0) {
936 cluster_size
= bdi
.cluster_size
;
938 cluster_size
= BLOCK_SIZE
;
942 if (total_sectors
- addr
< BDRV_SECTORS_PER_DIRTY_CHUNK
) {
943 nr_sectors
= total_sectors
- addr
;
945 nr_sectors
= BDRV_SECTORS_PER_DIRTY_CHUNK
;
948 if (flags
& BLK_MIG_FLAG_ZERO_BLOCK
) {
949 ret
= blk_pwrite_zeroes(blk
, addr
* BDRV_SECTOR_SIZE
,
950 nr_sectors
* BDRV_SECTOR_SIZE
,
957 buf
= g_malloc(BLOCK_SIZE
);
958 qemu_get_buffer(f
, buf
, BLOCK_SIZE
);
959 for (i
= 0; i
< BLOCK_SIZE
/ cluster_size
; i
++) {
960 cur_addr
= addr
* BDRV_SECTOR_SIZE
+ i
* cluster_size
;
961 cur_buf
= buf
+ i
* cluster_size
;
963 if ((!block_mig_state
.zero_blocks
||
964 cluster_size
< BLOCK_SIZE
) &&
965 buffer_is_zero(cur_buf
, cluster_size
)) {
966 ret
= blk_pwrite_zeroes(blk
, cur_addr
,
970 ret
= blk_pwrite(blk
, cur_addr
, cur_buf
,
983 } else if (flags
& BLK_MIG_FLAG_PROGRESS
) {
984 if (!banner_printed
) {
985 printf("Receiving block device images\n");
988 printf("Completed %d %%%c", (int)addr
,
989 (addr
== 100) ? '\n' : '\r');
991 } else if (!(flags
& BLK_MIG_FLAG_EOS
)) {
992 fprintf(stderr
, "Unknown block migration flags: %#x\n", flags
);
995 ret
= qemu_file_get_error(f
);
999 } while (!(flags
& BLK_MIG_FLAG_EOS
));
1004 static bool block_is_active(void *opaque
)
1006 return migrate_use_block();
1009 static SaveVMHandlers savevm_block_handlers
= {
1010 .save_live_setup
= block_save_setup
,
1011 .save_live_iterate
= block_save_iterate
,
1012 .save_live_complete_precopy
= block_save_complete
,
1013 .save_live_pending
= block_save_pending
,
1014 .load_state
= block_load
,
1015 .cleanup
= block_migration_cleanup
,
1016 .is_active
= block_is_active
,
1019 void blk_mig_init(void)
1021 QSIMPLEQ_INIT(&block_mig_state
.bmds_list
);
1022 QSIMPLEQ_INIT(&block_mig_state
.blk_list
);
1023 qemu_mutex_init(&block_mig_state
.lock
);
1025 register_savevm_live(NULL
, "block", 0, 1, &savevm_block_handlers
,