849 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			849 lines
		
	
	
		
			22 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
 | |
|  * QEMU live block migration
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|  *
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|  * Copyright IBM, Corp. 2009
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|  *
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|  * Authors:
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|  *  Liran Schour   <lirans@il.ibm.com>
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|  *
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|  * This work is licensed under the terms of the GNU GPL, version 2.  See
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|  * the COPYING file in the top-level directory.
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|  *
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|  * Contributions after 2012-01-13 are licensed under the terms of the
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|  * GNU GPL, version 2 or (at your option) any later version.
 | |
|  */
 | |
| 
 | |
| #include "qemu-common.h"
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| #include "block/block_int.h"
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| #include "hw/hw.h"
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| #include "qemu/queue.h"
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| #include "qemu/timer.h"
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| #include "migration/block.h"
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| #include "migration/migration.h"
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| #include "sysemu/blockdev.h"
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| #include <assert.h>
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| 
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| #define BLOCK_SIZE                       (1 << 20)
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| #define BDRV_SECTORS_PER_DIRTY_CHUNK     (BLOCK_SIZE >> BDRV_SECTOR_BITS)
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| 
 | |
| #define BLK_MIG_FLAG_DEVICE_BLOCK       0x01
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| #define BLK_MIG_FLAG_EOS                0x02
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| #define BLK_MIG_FLAG_PROGRESS           0x04
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| #define BLK_MIG_FLAG_ZERO_BLOCK         0x08
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| 
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| #define MAX_IS_ALLOCATED_SEARCH 65536
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| 
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| //#define DEBUG_BLK_MIGRATION
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| 
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| #ifdef DEBUG_BLK_MIGRATION
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| #define DPRINTF(fmt, ...) \
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|     do { printf("blk_migration: " fmt, ## __VA_ARGS__); } while (0)
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| #else
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| #define DPRINTF(fmt, ...) \
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|     do { } while (0)
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| #endif
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| 
 | |
| typedef struct BlkMigDevState {
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|     /* Written during setup phase.  Can be read without a lock.  */
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|     BlockDriverState *bs;
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|     int shared_base;
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|     int64_t total_sectors;
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|     QSIMPLEQ_ENTRY(BlkMigDevState) entry;
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| 
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|     /* Only used by migration thread.  Does not need a lock.  */
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|     int bulk_completed;
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|     int64_t cur_sector;
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|     int64_t cur_dirty;
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| 
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|     /* Protected by block migration lock.  */
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|     unsigned long *aio_bitmap;
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|     int64_t completed_sectors;
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| } BlkMigDevState;
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| 
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| typedef struct BlkMigBlock {
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|     /* Only used by migration thread.  */
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|     uint8_t *buf;
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|     BlkMigDevState *bmds;
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|     int64_t sector;
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|     int nr_sectors;
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|     struct iovec iov;
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|     QEMUIOVector qiov;
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|     BlockDriverAIOCB *aiocb;
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| 
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|     /* Protected by block migration lock.  */
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|     int ret;
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|     QSIMPLEQ_ENTRY(BlkMigBlock) entry;
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| } BlkMigBlock;
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| 
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| typedef struct BlkMigState {
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|     /* Written during setup phase.  Can be read without a lock.  */
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|     int blk_enable;
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|     int shared_base;
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|     QSIMPLEQ_HEAD(bmds_list, BlkMigDevState) bmds_list;
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|     int64_t total_sector_sum;
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|     bool zero_blocks;
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| 
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|     /* Protected by lock.  */
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|     QSIMPLEQ_HEAD(blk_list, BlkMigBlock) blk_list;
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|     int submitted;
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|     int read_done;
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| 
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|     /* Only used by migration thread.  Does not need a lock.  */
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|     int transferred;
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|     int prev_progress;
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|     int bulk_completed;
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| 
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|     /* Lock must be taken _inside_ the iothread lock.  */
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|     QemuMutex lock;
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| } BlkMigState;
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| 
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| static BlkMigState block_mig_state;
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| 
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| static void blk_mig_lock(void)
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| {
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|     qemu_mutex_lock(&block_mig_state.lock);
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| }
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| 
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| static void blk_mig_unlock(void)
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| {
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|     qemu_mutex_unlock(&block_mig_state.lock);
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| }
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| 
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| /* Must run outside of the iothread lock during the bulk phase,
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|  * or the VM will stall.
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|  */
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| 
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| static void blk_send(QEMUFile *f, BlkMigBlock * blk)
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| {
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|     int len;
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|     uint64_t flags = BLK_MIG_FLAG_DEVICE_BLOCK;
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| 
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|     if (block_mig_state.zero_blocks &&
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|         buffer_is_zero(blk->buf, BLOCK_SIZE)) {
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|         flags |= BLK_MIG_FLAG_ZERO_BLOCK;
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|     }
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| 
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|     /* sector number and flags */
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|     qemu_put_be64(f, (blk->sector << BDRV_SECTOR_BITS)
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|                      | flags);
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| 
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|     /* device name */
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|     len = strlen(blk->bmds->bs->device_name);
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|     qemu_put_byte(f, len);
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|     qemu_put_buffer(f, (uint8_t *)blk->bmds->bs->device_name, len);
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| 
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|     /* if a block is zero we need to flush here since the network
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|      * bandwidth is now a lot higher than the storage device bandwidth.
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|      * thus if we queue zero blocks we slow down the migration */
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|     if (flags & BLK_MIG_FLAG_ZERO_BLOCK) {
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|         qemu_fflush(f);
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|         return;
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|     }
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| 
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|     qemu_put_buffer(f, blk->buf, BLOCK_SIZE);
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| }
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| 
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| int blk_mig_active(void)
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| {
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|     return !QSIMPLEQ_EMPTY(&block_mig_state.bmds_list);
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| }
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| 
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| uint64_t blk_mig_bytes_transferred(void)
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| {
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|     BlkMigDevState *bmds;
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|     uint64_t sum = 0;
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| 
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|     blk_mig_lock();
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|     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
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|         sum += bmds->completed_sectors;
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|     }
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|     blk_mig_unlock();
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|     return sum << BDRV_SECTOR_BITS;
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| }
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| 
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| uint64_t blk_mig_bytes_remaining(void)
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| {
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|     return blk_mig_bytes_total() - blk_mig_bytes_transferred();
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| }
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| 
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| uint64_t blk_mig_bytes_total(void)
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| {
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|     BlkMigDevState *bmds;
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|     uint64_t sum = 0;
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| 
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|     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
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|         sum += bmds->total_sectors;
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|     }
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|     return sum << BDRV_SECTOR_BITS;
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| }
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| 
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| 
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| /* Called with migration lock held.  */
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| 
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| static int bmds_aio_inflight(BlkMigDevState *bmds, int64_t sector)
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| {
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|     int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
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| 
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|     if ((sector << BDRV_SECTOR_BITS) < bdrv_getlength(bmds->bs)) {
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|         return !!(bmds->aio_bitmap[chunk / (sizeof(unsigned long) * 8)] &
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|             (1UL << (chunk % (sizeof(unsigned long) * 8))));
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|     } else {
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|         return 0;
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|     }
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| }
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| 
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| /* Called with migration lock held.  */
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| 
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| static void bmds_set_aio_inflight(BlkMigDevState *bmds, int64_t sector_num,
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|                              int nb_sectors, int set)
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| {
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|     int64_t start, end;
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|     unsigned long val, idx, bit;
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| 
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|     start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
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|     end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
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| 
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|     for (; start <= end; start++) {
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|         idx = start / (sizeof(unsigned long) * 8);
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|         bit = start % (sizeof(unsigned long) * 8);
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|         val = bmds->aio_bitmap[idx];
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|         if (set) {
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|             val |= 1UL << bit;
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|         } else {
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|             val &= ~(1UL << bit);
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|         }
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|         bmds->aio_bitmap[idx] = val;
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|     }
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| }
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| 
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| static void alloc_aio_bitmap(BlkMigDevState *bmds)
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| {
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|     BlockDriverState *bs = bmds->bs;
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|     int64_t bitmap_size;
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| 
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|     bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
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|             BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
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|     bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
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| 
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|     bmds->aio_bitmap = g_malloc0(bitmap_size);
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| }
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| 
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| /* Never hold migration lock when yielding to the main loop!  */
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| 
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| static void blk_mig_read_cb(void *opaque, int ret)
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| {
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|     BlkMigBlock *blk = opaque;
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| 
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|     blk_mig_lock();
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|     blk->ret = ret;
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| 
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|     QSIMPLEQ_INSERT_TAIL(&block_mig_state.blk_list, blk, entry);
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|     bmds_set_aio_inflight(blk->bmds, blk->sector, blk->nr_sectors, 0);
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| 
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|     block_mig_state.submitted--;
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|     block_mig_state.read_done++;
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|     assert(block_mig_state.submitted >= 0);
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|     blk_mig_unlock();
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| }
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| 
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| /* Called with no lock taken.  */
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| 
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| static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
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| {
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|     int64_t total_sectors = bmds->total_sectors;
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|     int64_t cur_sector = bmds->cur_sector;
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|     BlockDriverState *bs = bmds->bs;
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|     BlkMigBlock *blk;
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|     int nr_sectors;
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| 
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|     if (bmds->shared_base) {
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|         qemu_mutex_lock_iothread();
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|         while (cur_sector < total_sectors &&
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|                !bdrv_is_allocated(bs, cur_sector, MAX_IS_ALLOCATED_SEARCH,
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|                                   &nr_sectors)) {
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|             cur_sector += nr_sectors;
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|         }
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|         qemu_mutex_unlock_iothread();
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|     }
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| 
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|     if (cur_sector >= total_sectors) {
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|         bmds->cur_sector = bmds->completed_sectors = total_sectors;
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|         return 1;
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|     }
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| 
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|     bmds->completed_sectors = cur_sector;
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| 
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|     cur_sector &= ~((int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK - 1);
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| 
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|     /* we are going to transfer a full block even if it is not allocated */
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|     nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
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| 
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|     if (total_sectors - cur_sector < BDRV_SECTORS_PER_DIRTY_CHUNK) {
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|         nr_sectors = total_sectors - cur_sector;
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|     }
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| 
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|     blk = g_malloc(sizeof(BlkMigBlock));
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|     blk->buf = g_malloc(BLOCK_SIZE);
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|     blk->bmds = bmds;
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|     blk->sector = cur_sector;
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|     blk->nr_sectors = nr_sectors;
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| 
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|     blk->iov.iov_base = blk->buf;
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|     blk->iov.iov_len = nr_sectors * BDRV_SECTOR_SIZE;
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|     qemu_iovec_init_external(&blk->qiov, &blk->iov, 1);
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| 
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|     blk_mig_lock();
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|     block_mig_state.submitted++;
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|     blk_mig_unlock();
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| 
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|     qemu_mutex_lock_iothread();
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|     blk->aiocb = bdrv_aio_readv(bs, cur_sector, &blk->qiov,
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|                                 nr_sectors, blk_mig_read_cb, blk);
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| 
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|     bdrv_reset_dirty(bs, cur_sector, nr_sectors);
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|     qemu_mutex_unlock_iothread();
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| 
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|     bmds->cur_sector = cur_sector + nr_sectors;
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|     return (bmds->cur_sector >= total_sectors);
 | |
| }
 | |
| 
 | |
| /* Called with iothread lock taken.  */
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| 
 | |
| static void set_dirty_tracking(int enable)
 | |
| {
 | |
|     BlkMigDevState *bmds;
 | |
| 
 | |
|     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
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|         bdrv_set_dirty_tracking(bmds->bs, enable ? BLOCK_SIZE : 0);
 | |
|     }
 | |
| }
 | |
| 
 | |
| static void init_blk_migration_it(void *opaque, BlockDriverState *bs)
 | |
| {
 | |
|     BlkMigDevState *bmds;
 | |
|     int64_t sectors;
 | |
| 
 | |
|     if (!bdrv_is_read_only(bs)) {
 | |
|         sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
 | |
|         if (sectors <= 0) {
 | |
|             return;
 | |
|         }
 | |
| 
 | |
|         bmds = g_malloc0(sizeof(BlkMigDevState));
 | |
|         bmds->bs = bs;
 | |
|         bmds->bulk_completed = 0;
 | |
|         bmds->total_sectors = sectors;
 | |
|         bmds->completed_sectors = 0;
 | |
|         bmds->shared_base = block_mig_state.shared_base;
 | |
|         alloc_aio_bitmap(bmds);
 | |
|         bdrv_set_in_use(bs, 1);
 | |
|         bdrv_ref(bs);
 | |
| 
 | |
|         block_mig_state.total_sector_sum += sectors;
 | |
| 
 | |
|         if (bmds->shared_base) {
 | |
|             DPRINTF("Start migration for %s with shared base image\n",
 | |
|                     bs->device_name);
 | |
|         } else {
 | |
|             DPRINTF("Start full migration for %s\n", bs->device_name);
 | |
|         }
 | |
| 
 | |
|         QSIMPLEQ_INSERT_TAIL(&block_mig_state.bmds_list, bmds, entry);
 | |
|     }
 | |
| }
 | |
| 
 | |
| static void init_blk_migration(QEMUFile *f)
 | |
| {
 | |
|     block_mig_state.submitted = 0;
 | |
|     block_mig_state.read_done = 0;
 | |
|     block_mig_state.transferred = 0;
 | |
|     block_mig_state.total_sector_sum = 0;
 | |
|     block_mig_state.prev_progress = -1;
 | |
|     block_mig_state.bulk_completed = 0;
 | |
|     block_mig_state.zero_blocks = migrate_zero_blocks();
 | |
| 
 | |
|     bdrv_iterate(init_blk_migration_it, NULL);
 | |
| }
 | |
| 
 | |
| /* Called with no lock taken.  */
 | |
| 
 | |
| static int blk_mig_save_bulked_block(QEMUFile *f)
 | |
| {
 | |
|     int64_t completed_sector_sum = 0;
 | |
|     BlkMigDevState *bmds;
 | |
|     int progress;
 | |
|     int ret = 0;
 | |
| 
 | |
|     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
 | |
|         if (bmds->bulk_completed == 0) {
 | |
|             if (mig_save_device_bulk(f, bmds) == 1) {
 | |
|                 /* completed bulk section for this device */
 | |
|                 bmds->bulk_completed = 1;
 | |
|             }
 | |
|             completed_sector_sum += bmds->completed_sectors;
 | |
|             ret = 1;
 | |
|             break;
 | |
|         } else {
 | |
|             completed_sector_sum += bmds->completed_sectors;
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     if (block_mig_state.total_sector_sum != 0) {
 | |
|         progress = completed_sector_sum * 100 /
 | |
|                    block_mig_state.total_sector_sum;
 | |
|     } else {
 | |
|         progress = 100;
 | |
|     }
 | |
|     if (progress != block_mig_state.prev_progress) {
 | |
|         block_mig_state.prev_progress = progress;
 | |
|         qemu_put_be64(f, (progress << BDRV_SECTOR_BITS)
 | |
|                          | BLK_MIG_FLAG_PROGRESS);
 | |
|         DPRINTF("Completed %d %%\r", progress);
 | |
|     }
 | |
| 
 | |
|     return ret;
 | |
| }
 | |
| 
 | |
| static void blk_mig_reset_dirty_cursor(void)
 | |
| {
 | |
|     BlkMigDevState *bmds;
 | |
| 
 | |
|     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
 | |
|         bmds->cur_dirty = 0;
 | |
|     }
 | |
| }
 | |
| 
 | |
| /* Called with iothread lock taken.  */
 | |
| 
 | |
| static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds,
 | |
|                                  int is_async)
 | |
| {
 | |
|     BlkMigBlock *blk;
 | |
|     int64_t total_sectors = bmds->total_sectors;
 | |
|     int64_t sector;
 | |
|     int nr_sectors;
 | |
|     int ret = -EIO;
 | |
| 
 | |
|     for (sector = bmds->cur_dirty; sector < bmds->total_sectors;) {
 | |
|         blk_mig_lock();
 | |
|         if (bmds_aio_inflight(bmds, sector)) {
 | |
|             blk_mig_unlock();
 | |
|             bdrv_drain_all();
 | |
|         } else {
 | |
|             blk_mig_unlock();
 | |
|         }
 | |
|         if (bdrv_get_dirty(bmds->bs, sector)) {
 | |
| 
 | |
|             if (total_sectors - sector < BDRV_SECTORS_PER_DIRTY_CHUNK) {
 | |
|                 nr_sectors = total_sectors - sector;
 | |
|             } else {
 | |
|                 nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
 | |
|             }
 | |
|             blk = g_malloc(sizeof(BlkMigBlock));
 | |
|             blk->buf = g_malloc(BLOCK_SIZE);
 | |
|             blk->bmds = bmds;
 | |
|             blk->sector = sector;
 | |
|             blk->nr_sectors = nr_sectors;
 | |
| 
 | |
|             if (is_async) {
 | |
|                 blk->iov.iov_base = blk->buf;
 | |
|                 blk->iov.iov_len = nr_sectors * BDRV_SECTOR_SIZE;
 | |
|                 qemu_iovec_init_external(&blk->qiov, &blk->iov, 1);
 | |
| 
 | |
|                 blk->aiocb = bdrv_aio_readv(bmds->bs, sector, &blk->qiov,
 | |
|                                             nr_sectors, blk_mig_read_cb, blk);
 | |
| 
 | |
|                 blk_mig_lock();
 | |
|                 block_mig_state.submitted++;
 | |
|                 bmds_set_aio_inflight(bmds, sector, nr_sectors, 1);
 | |
|                 blk_mig_unlock();
 | |
|             } else {
 | |
|                 ret = bdrv_read(bmds->bs, sector, blk->buf, nr_sectors);
 | |
|                 if (ret < 0) {
 | |
|                     goto error;
 | |
|                 }
 | |
|                 blk_send(f, blk);
 | |
| 
 | |
|                 g_free(blk->buf);
 | |
|                 g_free(blk);
 | |
|             }
 | |
| 
 | |
|             bdrv_reset_dirty(bmds->bs, sector, nr_sectors);
 | |
|             break;
 | |
|         }
 | |
|         sector += BDRV_SECTORS_PER_DIRTY_CHUNK;
 | |
|         bmds->cur_dirty = sector;
 | |
|     }
 | |
| 
 | |
|     return (bmds->cur_dirty >= bmds->total_sectors);
 | |
| 
 | |
| error:
 | |
|     DPRINTF("Error reading sector %" PRId64 "\n", sector);
 | |
|     g_free(blk->buf);
 | |
|     g_free(blk);
 | |
|     return ret;
 | |
| }
 | |
| 
 | |
| /* Called with iothread lock taken.
 | |
|  *
 | |
|  * return value:
 | |
|  * 0: too much data for max_downtime
 | |
|  * 1: few enough data for max_downtime
 | |
| */
 | |
| static int blk_mig_save_dirty_block(QEMUFile *f, int is_async)
 | |
| {
 | |
|     BlkMigDevState *bmds;
 | |
|     int ret = 1;
 | |
| 
 | |
|     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
 | |
|         ret = mig_save_device_dirty(f, bmds, is_async);
 | |
|         if (ret <= 0) {
 | |
|             break;
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     return ret;
 | |
| }
 | |
| 
 | |
| /* Called with no locks taken.  */
 | |
| 
 | |
| static int flush_blks(QEMUFile *f)
 | |
| {
 | |
|     BlkMigBlock *blk;
 | |
|     int ret = 0;
 | |
| 
 | |
|     DPRINTF("%s Enter submitted %d read_done %d transferred %d\n",
 | |
|             __FUNCTION__, block_mig_state.submitted, block_mig_state.read_done,
 | |
|             block_mig_state.transferred);
 | |
| 
 | |
|     blk_mig_lock();
 | |
|     while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) {
 | |
|         if (qemu_file_rate_limit(f)) {
 | |
|             break;
 | |
|         }
 | |
|         if (blk->ret < 0) {
 | |
|             ret = blk->ret;
 | |
|             break;
 | |
|         }
 | |
| 
 | |
|         QSIMPLEQ_REMOVE_HEAD(&block_mig_state.blk_list, entry);
 | |
|         blk_mig_unlock();
 | |
|         blk_send(f, blk);
 | |
|         blk_mig_lock();
 | |
| 
 | |
|         g_free(blk->buf);
 | |
|         g_free(blk);
 | |
| 
 | |
|         block_mig_state.read_done--;
 | |
|         block_mig_state.transferred++;
 | |
|         assert(block_mig_state.read_done >= 0);
 | |
|     }
 | |
|     blk_mig_unlock();
 | |
| 
 | |
|     DPRINTF("%s Exit submitted %d read_done %d transferred %d\n", __FUNCTION__,
 | |
|             block_mig_state.submitted, block_mig_state.read_done,
 | |
|             block_mig_state.transferred);
 | |
|     return ret;
 | |
| }
 | |
| 
 | |
| /* Called with iothread lock taken.  */
 | |
| 
 | |
| static int64_t get_remaining_dirty(void)
 | |
| {
 | |
|     BlkMigDevState *bmds;
 | |
|     int64_t dirty = 0;
 | |
| 
 | |
|     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
 | |
|         dirty += bdrv_get_dirty_count(bmds->bs);
 | |
|     }
 | |
| 
 | |
|     return dirty << BDRV_SECTOR_BITS;
 | |
| }
 | |
| 
 | |
| /* Called with iothread lock taken.  */
 | |
| 
 | |
| static void blk_mig_cleanup(void)
 | |
| {
 | |
|     BlkMigDevState *bmds;
 | |
|     BlkMigBlock *blk;
 | |
| 
 | |
|     bdrv_drain_all();
 | |
| 
 | |
|     set_dirty_tracking(0);
 | |
| 
 | |
|     blk_mig_lock();
 | |
|     while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != NULL) {
 | |
|         QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry);
 | |
|         bdrv_set_in_use(bmds->bs, 0);
 | |
|         bdrv_unref(bmds->bs);
 | |
|         g_free(bmds->aio_bitmap);
 | |
|         g_free(bmds);
 | |
|     }
 | |
| 
 | |
|     while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) {
 | |
|         QSIMPLEQ_REMOVE_HEAD(&block_mig_state.blk_list, entry);
 | |
|         g_free(blk->buf);
 | |
|         g_free(blk);
 | |
|     }
 | |
|     blk_mig_unlock();
 | |
| }
 | |
| 
 | |
| static void block_migration_cancel(void *opaque)
 | |
| {
 | |
|     blk_mig_cleanup();
 | |
| }
 | |
| 
 | |
| static int block_save_setup(QEMUFile *f, void *opaque)
 | |
| {
 | |
|     int ret;
 | |
| 
 | |
|     DPRINTF("Enter save live setup submitted %d transferred %d\n",
 | |
|             block_mig_state.submitted, block_mig_state.transferred);
 | |
| 
 | |
|     qemu_mutex_lock_iothread();
 | |
|     init_blk_migration(f);
 | |
| 
 | |
|     /* start track dirty blocks */
 | |
|     set_dirty_tracking(1);
 | |
|     qemu_mutex_unlock_iothread();
 | |
| 
 | |
|     ret = flush_blks(f);
 | |
|     blk_mig_reset_dirty_cursor();
 | |
|     qemu_put_be64(f, BLK_MIG_FLAG_EOS);
 | |
| 
 | |
|     return ret;
 | |
| }
 | |
| 
 | |
| static int block_save_iterate(QEMUFile *f, void *opaque)
 | |
| {
 | |
|     int ret;
 | |
|     int64_t last_ftell = qemu_ftell(f);
 | |
| 
 | |
|     DPRINTF("Enter save live iterate submitted %d transferred %d\n",
 | |
|             block_mig_state.submitted, block_mig_state.transferred);
 | |
| 
 | |
|     ret = flush_blks(f);
 | |
|     if (ret) {
 | |
|         return ret;
 | |
|     }
 | |
| 
 | |
|     blk_mig_reset_dirty_cursor();
 | |
| 
 | |
|     /* control the rate of transfer */
 | |
|     blk_mig_lock();
 | |
|     while ((block_mig_state.submitted +
 | |
|             block_mig_state.read_done) * BLOCK_SIZE <
 | |
|            qemu_file_get_rate_limit(f)) {
 | |
|         blk_mig_unlock();
 | |
|         if (block_mig_state.bulk_completed == 0) {
 | |
|             /* first finish the bulk phase */
 | |
|             if (blk_mig_save_bulked_block(f) == 0) {
 | |
|                 /* finished saving bulk on all devices */
 | |
|                 block_mig_state.bulk_completed = 1;
 | |
|             }
 | |
|             ret = 0;
 | |
|         } else {
 | |
|             /* Always called with iothread lock taken for
 | |
|              * simplicity, block_save_complete also calls it.
 | |
|              */
 | |
|             qemu_mutex_lock_iothread();
 | |
|             ret = blk_mig_save_dirty_block(f, 1);
 | |
|             qemu_mutex_unlock_iothread();
 | |
|         }
 | |
|         if (ret < 0) {
 | |
|             return ret;
 | |
|         }
 | |
|         blk_mig_lock();
 | |
|         if (ret != 0) {
 | |
|             /* no more dirty blocks */
 | |
|             break;
 | |
|         }
 | |
|     }
 | |
|     blk_mig_unlock();
 | |
| 
 | |
|     ret = flush_blks(f);
 | |
|     if (ret) {
 | |
|         return ret;
 | |
|     }
 | |
| 
 | |
|     qemu_put_be64(f, BLK_MIG_FLAG_EOS);
 | |
|     return qemu_ftell(f) - last_ftell;
 | |
| }
 | |
| 
 | |
| /* Called with iothread lock taken.  */
 | |
| 
 | |
| static int block_save_complete(QEMUFile *f, void *opaque)
 | |
| {
 | |
|     int ret;
 | |
| 
 | |
|     DPRINTF("Enter save live complete submitted %d transferred %d\n",
 | |
|             block_mig_state.submitted, block_mig_state.transferred);
 | |
| 
 | |
|     ret = flush_blks(f);
 | |
|     if (ret) {
 | |
|         return ret;
 | |
|     }
 | |
| 
 | |
|     blk_mig_reset_dirty_cursor();
 | |
| 
 | |
|     /* we know for sure that save bulk is completed and
 | |
|        all async read completed */
 | |
|     blk_mig_lock();
 | |
|     assert(block_mig_state.submitted == 0);
 | |
|     blk_mig_unlock();
 | |
| 
 | |
|     do {
 | |
|         ret = blk_mig_save_dirty_block(f, 0);
 | |
|         if (ret < 0) {
 | |
|             return ret;
 | |
|         }
 | |
|     } while (ret == 0);
 | |
| 
 | |
|     /* report completion */
 | |
|     qemu_put_be64(f, (100 << BDRV_SECTOR_BITS) | BLK_MIG_FLAG_PROGRESS);
 | |
| 
 | |
|     DPRINTF("Block migration completed\n");
 | |
| 
 | |
|     qemu_put_be64(f, BLK_MIG_FLAG_EOS);
 | |
| 
 | |
|     blk_mig_cleanup();
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| static uint64_t block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
 | |
| {
 | |
|     /* Estimate pending number of bytes to send */
 | |
|     uint64_t pending;
 | |
| 
 | |
|     qemu_mutex_lock_iothread();
 | |
|     blk_mig_lock();
 | |
|     pending = get_remaining_dirty() +
 | |
|                        block_mig_state.submitted * BLOCK_SIZE +
 | |
|                        block_mig_state.read_done * BLOCK_SIZE;
 | |
| 
 | |
|     /* Report at least one block pending during bulk phase */
 | |
|     if (pending == 0 && !block_mig_state.bulk_completed) {
 | |
|         pending = BLOCK_SIZE;
 | |
|     }
 | |
|     blk_mig_unlock();
 | |
|     qemu_mutex_unlock_iothread();
 | |
| 
 | |
|     DPRINTF("Enter save live pending  %" PRIu64 "\n", pending);
 | |
|     return pending;
 | |
| }
 | |
| 
 | |
| static int block_load(QEMUFile *f, void *opaque, int version_id)
 | |
| {
 | |
|     static int banner_printed;
 | |
|     int len, flags;
 | |
|     char device_name[256];
 | |
|     int64_t addr;
 | |
|     BlockDriverState *bs, *bs_prev = NULL;
 | |
|     uint8_t *buf;
 | |
|     int64_t total_sectors = 0;
 | |
|     int nr_sectors;
 | |
|     int ret;
 | |
| 
 | |
|     do {
 | |
|         addr = qemu_get_be64(f);
 | |
| 
 | |
|         flags = addr & ~BDRV_SECTOR_MASK;
 | |
|         addr >>= BDRV_SECTOR_BITS;
 | |
| 
 | |
|         if (flags & BLK_MIG_FLAG_DEVICE_BLOCK) {
 | |
|             /* get device name */
 | |
|             len = qemu_get_byte(f);
 | |
|             qemu_get_buffer(f, (uint8_t *)device_name, len);
 | |
|             device_name[len] = '\0';
 | |
| 
 | |
|             bs = bdrv_find(device_name);
 | |
|             if (!bs) {
 | |
|                 fprintf(stderr, "Error unknown block device %s\n",
 | |
|                         device_name);
 | |
|                 return -EINVAL;
 | |
|             }
 | |
| 
 | |
|             if (bs != bs_prev) {
 | |
|                 bs_prev = bs;
 | |
|                 total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
 | |
|                 if (total_sectors <= 0) {
 | |
|                     error_report("Error getting length of block device %s",
 | |
|                                  device_name);
 | |
|                     return -EINVAL;
 | |
|                 }
 | |
|             }
 | |
| 
 | |
|             if (total_sectors - addr < BDRV_SECTORS_PER_DIRTY_CHUNK) {
 | |
|                 nr_sectors = total_sectors - addr;
 | |
|             } else {
 | |
|                 nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
 | |
|             }
 | |
| 
 | |
|             if (flags & BLK_MIG_FLAG_ZERO_BLOCK) {
 | |
|                 ret = bdrv_write_zeroes(bs, addr, nr_sectors);
 | |
|             } else {
 | |
|                 buf = g_malloc(BLOCK_SIZE);
 | |
|                 qemu_get_buffer(f, buf, BLOCK_SIZE);
 | |
|                 ret = bdrv_write(bs, addr, buf, nr_sectors);
 | |
|                 g_free(buf);
 | |
|             }
 | |
| 
 | |
|             if (ret < 0) {
 | |
|                 return ret;
 | |
|             }
 | |
|         } else if (flags & BLK_MIG_FLAG_PROGRESS) {
 | |
|             if (!banner_printed) {
 | |
|                 printf("Receiving block device images\n");
 | |
|                 banner_printed = 1;
 | |
|             }
 | |
|             printf("Completed %d %%%c", (int)addr,
 | |
|                    (addr == 100) ? '\n' : '\r');
 | |
|             fflush(stdout);
 | |
|         } else if (!(flags & BLK_MIG_FLAG_EOS)) {
 | |
|             fprintf(stderr, "Unknown block migration flags: %#x\n", flags);
 | |
|             return -EINVAL;
 | |
|         }
 | |
|         ret = qemu_file_get_error(f);
 | |
|         if (ret != 0) {
 | |
|             return ret;
 | |
|         }
 | |
|     } while (!(flags & BLK_MIG_FLAG_EOS));
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| static void block_set_params(const MigrationParams *params, void *opaque)
 | |
| {
 | |
|     block_mig_state.blk_enable = params->blk;
 | |
|     block_mig_state.shared_base = params->shared;
 | |
| 
 | |
|     /* shared base means that blk_enable = 1 */
 | |
|     block_mig_state.blk_enable |= params->shared;
 | |
| }
 | |
| 
 | |
| static bool block_is_active(void *opaque)
 | |
| {
 | |
|     return block_mig_state.blk_enable == 1;
 | |
| }
 | |
| 
 | |
| SaveVMHandlers savevm_block_handlers = {
 | |
|     .set_params = block_set_params,
 | |
|     .save_live_setup = block_save_setup,
 | |
|     .save_live_iterate = block_save_iterate,
 | |
|     .save_live_complete = block_save_complete,
 | |
|     .save_live_pending = block_save_pending,
 | |
|     .load_state = block_load,
 | |
|     .cancel = block_migration_cancel,
 | |
|     .is_active = block_is_active,
 | |
| };
 | |
| 
 | |
| void blk_mig_init(void)
 | |
| {
 | |
|     QSIMPLEQ_INIT(&block_mig_state.bmds_list);
 | |
|     QSIMPLEQ_INIT(&block_mig_state.blk_list);
 | |
|     qemu_mutex_init(&block_mig_state.lock);
 | |
| 
 | |
|     register_savevm_live(NULL, "block", 0, 1, &savevm_block_handlers,
 | |
|                          &block_mig_state);
 | |
| }
 |