883 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			883 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			C
		
	
	
	
/*
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 * 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.
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 */
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#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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#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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#define MAX_IS_ALLOCATED_SEARCH 65536
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//#define DEBUG_BLK_MIGRATION
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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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    /* 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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    /* 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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    BdrvDirtyBitmap *dirty_bitmap;
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    Error *blocker;
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} BlkMigDevState;
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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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    /* 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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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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    /* 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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    /* 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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    /* Lock must be taken _inside_ the iothread lock.  */
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    QemuMutex lock;
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} BlkMigState;
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static BlkMigState block_mig_state;
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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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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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/* 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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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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    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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    /* 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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    /* 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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    /* 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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    qemu_put_buffer(f, blk->buf, BLOCK_SIZE);
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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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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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    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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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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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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    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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/* Called with migration lock held.  */
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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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    if (sector < bdrv_nb_sectors(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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/* Called with migration lock held.  */
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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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    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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    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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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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    bitmap_size = bdrv_nb_sectors(bs) + BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
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    bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
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    bmds->aio_bitmap = g_malloc0(bitmap_size);
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}
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/* Never hold migration lock when yielding to the main loop!  */
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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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    blk_mig_lock();
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    blk->ret = ret;
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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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    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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/* Called with no lock taken.  */
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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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    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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    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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    bmds->completed_sectors = cur_sector;
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    cur_sector &= ~((int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK - 1);
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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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    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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    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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    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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    blk_mig_lock();
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    block_mig_state.submitted++;
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    blk_mig_unlock();
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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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    bdrv_reset_dirty(bs, cur_sector, nr_sectors);
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    qemu_mutex_unlock_iothread();
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    bmds->cur_sector = cur_sector + nr_sectors;
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    return (bmds->cur_sector >= total_sectors);
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}
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/* Called with iothread lock taken.  */
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static int set_dirty_tracking(void)
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{
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    BlkMigDevState *bmds;
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    int ret;
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    QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
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        bmds->dirty_bitmap = bdrv_create_dirty_bitmap(bmds->bs, BLOCK_SIZE,
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                                                      NULL);
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        if (!bmds->dirty_bitmap) {
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            ret = -errno;
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            goto fail;
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        }
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    }
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    return 0;
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fail:
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    QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
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        if (bmds->dirty_bitmap) {
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            bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap);
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        }
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    }
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    return ret;
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}
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static void unset_dirty_tracking(void)
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{
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    BlkMigDevState *bmds;
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    QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
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        bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap);
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    }
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}
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static void init_blk_migration_it(void *opaque, BlockDriverState *bs)
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{
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    BlkMigDevState *bmds;
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    int64_t sectors;
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    if (!bdrv_is_read_only(bs)) {
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        sectors = bdrv_nb_sectors(bs);
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        if (sectors <= 0) {
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            return;
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        }
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        bmds = g_malloc0(sizeof(BlkMigDevState));
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        bmds->bs = bs;
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        bmds->bulk_completed = 0;
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        bmds->total_sectors = sectors;
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        bmds->completed_sectors = 0;
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        bmds->shared_base = block_mig_state.shared_base;
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        alloc_aio_bitmap(bmds);
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        error_setg(&bmds->blocker, "block device is in use by migration");
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        bdrv_op_block_all(bs, bmds->blocker);
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        bdrv_ref(bs);
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        block_mig_state.total_sector_sum += sectors;
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 | 
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        if (bmds->shared_base) {
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            DPRINTF("Start migration for %s with shared base image\n",
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                    bs->device_name);
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        } else {
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            DPRINTF("Start full migration for %s\n", bs->device_name);
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        }
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        QSIMPLEQ_INSERT_TAIL(&block_mig_state.bmds_list, bmds, entry);
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    }
 | 
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}
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static void init_blk_migration(QEMUFile *f)
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{
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    block_mig_state.submitted = 0;
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    block_mig_state.read_done = 0;
 | 
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    block_mig_state.transferred = 0;
 | 
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    block_mig_state.total_sector_sum = 0;
 | 
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    block_mig_state.prev_progress = -1;
 | 
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    block_mig_state.bulk_completed = 0;
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    block_mig_state.zero_blocks = migrate_zero_blocks();
 | 
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 | 
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    bdrv_iterate(init_blk_migration_it, NULL);
 | 
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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 blk_mig_save_bulked_block(QEMUFile *f)
 | 
						|
{
 | 
						|
    int64_t completed_sector_sum = 0;
 | 
						|
    BlkMigDevState *bmds;
 | 
						|
    int progress;
 | 
						|
    int ret = 0;
 | 
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 | 
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    QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
 | 
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        if (bmds->bulk_completed == 0) {
 | 
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            if (mig_save_device_bulk(f, bmds) == 1) {
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                /* completed bulk section for this device */
 | 
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                bmds->bulk_completed = 1;
 | 
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            }
 | 
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            completed_sector_sum += bmds->completed_sectors;
 | 
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            ret = 1;
 | 
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            break;
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        } else {
 | 
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            completed_sector_sum += bmds->completed_sectors;
 | 
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        }
 | 
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    }
 | 
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 | 
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    if (block_mig_state.total_sector_sum != 0) {
 | 
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        progress = completed_sector_sum * 100 /
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                   block_mig_state.total_sector_sum;
 | 
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    } else {
 | 
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        progress = 100;
 | 
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    }
 | 
						|
    if (progress != block_mig_state.prev_progress) {
 | 
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        block_mig_state.prev_progress = progress;
 | 
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        qemu_put_be64(f, (progress << BDRV_SECTOR_BITS)
 | 
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                         | BLK_MIG_FLAG_PROGRESS);
 | 
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        DPRINTF("Completed %d %%\r", progress);
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    }
 | 
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 | 
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    return ret;
 | 
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}
 | 
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 | 
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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, bmds->dirty_bitmap, 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, bmds->dirty_bitmap);
 | 
						|
    }
 | 
						|
 | 
						|
    return dirty << BDRV_SECTOR_BITS;
 | 
						|
}
 | 
						|
 | 
						|
/* Called with iothread lock taken.  */
 | 
						|
 | 
						|
static void blk_mig_cleanup(void)
 | 
						|
{
 | 
						|
    BlkMigDevState *bmds;
 | 
						|
    BlkMigBlock *blk;
 | 
						|
 | 
						|
    bdrv_drain_all();
 | 
						|
 | 
						|
    unset_dirty_tracking();
 | 
						|
 | 
						|
    blk_mig_lock();
 | 
						|
    while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != NULL) {
 | 
						|
        QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry);
 | 
						|
        bdrv_op_unblock_all(bmds->bs, bmds->blocker);
 | 
						|
        error_free(bmds->blocker);
 | 
						|
        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 */
 | 
						|
    ret = set_dirty_tracking();
 | 
						|
 | 
						|
    if (ret) {
 | 
						|
        qemu_mutex_unlock_iothread();
 | 
						|
        return ret;
 | 
						|
    }
 | 
						|
 | 
						|
    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_nb_sectors(bs);
 | 
						|
                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,
 | 
						|
                                        BDRV_REQ_MAY_UNMAP);
 | 
						|
            } 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;
 | 
						|
}
 | 
						|
 | 
						|
static 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);
 | 
						|
}
 |