[qemu.git] / block-migration.c

/*
 * QEMU live block migration
 *
 * Copyright IBM, Corp. 2009
 *
 * Authors:
 *  Liran Schour   <lirans@il.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 */

#include "qemu-common.h"
#include "block_int.h"
#include "hw/hw.h"
#include "block-migration.h"
#include <assert.h>
#include <pthread.h>

#define SECTOR_BITS 9
#define SECTOR_SIZE (1 << SECTOR_BITS)
#define SECTOR_MASK ~(SECTOR_SIZE - 1);

#define BLOCK_SIZE (block_mig_state->sectors_per_block << SECTOR_BITS) 

#define BLK_MIG_FLAG_DEVICE_BLOCK       0x01
#define BLK_MIG_FLAG_EOS                0x02

#define MAX_IS_ALLOCATED_SEARCH 65536
#define MAX_BLOCKS_READ 10000
#define BLOCKS_READ_CHANGE 100
#define INITIAL_BLOCKS_READ 100

//#define DEBUG_BLK_MIGRATION

#ifdef DEBUG_BLK_MIGRATION
#define dprintf(fmt, ...)						\
    do { printf("blk_migration: " fmt, ## __VA_ARGS__); } while (0)
#else
#define dprintf(fmt, ...)			\
    do { } while (0)
#endif

typedef struct BlkMigBlock {
    uint8_t *buf;
    BlkMigDevState *bmds;
    int64_t sector;
    struct iovec iov;
    QEMUIOVector qiov;
    BlockDriverAIOCB *aiocb;
    int ret;
    struct BlkMigBlock *next;
} BlkMigBlock;

typedef struct BlkMigState {
    int bulk_completed;
    int blk_enable;
    int shared_base;
    int no_dirty;
    QEMUFile *load_file;
    BlkMigDevState *bmds_first;
    int sectors_per_block;
    BlkMigBlock *first_blk;
    BlkMigBlock *last_blk;
    int submitted;
    int read_done;
    int transferred;
    int64_t print_completion;
} BlkMigState;

static BlkMigState *block_mig_state = NULL;  

static void blk_mig_read_cb(void *opaque, int ret)
{
    BlkMigBlock *blk = opaque;
  
    blk->ret = ret;
    
    /* insert at the end */
    if(block_mig_state->last_blk == NULL) {
        block_mig_state->first_blk = blk;
        block_mig_state->last_blk = blk;
    } else {
        block_mig_state->last_blk->next = blk;
        block_mig_state->last_blk = blk;
    }
    
    block_mig_state->submitted--;
    block_mig_state->read_done++;
    assert(block_mig_state->submitted >= 0);
    
    return;
}

static int mig_read_device_bulk(QEMUFile *f, BlkMigDevState *bms)
{ 
    int nr_sectors;
    int64_t total_sectors, cur_sector = 0;
    BlockDriverState *bs = bms->bs;
    BlkMigBlock *blk;
    
    blk = qemu_malloc(sizeof(BlkMigBlock));
    blk->buf = qemu_malloc(BLOCK_SIZE);
    
    cur_sector = bms->cur_sector;
    total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
  
    if(bms->shared_base) {
        while(cur_sector < bms->total_sectors && 
              !bdrv_is_allocated(bms->bs, cur_sector, 
                                 MAX_IS_ALLOCATED_SEARCH, &nr_sectors)) {
            cur_sector += nr_sectors;
        }
    }
    
    if(cur_sector >= total_sectors) {
        bms->cur_sector = total_sectors;
        qemu_free(blk->buf);
        qemu_free(blk);
        return 1;
    }
  
    if(cur_sector >= block_mig_state->print_completion) {
        printf("Completed %" PRId64 " %%\r", cur_sector * 100 / total_sectors);
        fflush(stdout);
        block_mig_state->print_completion += 
            (block_mig_state->sectors_per_block * 10000);
    }
  
    /* we going to transfder BLOCK_SIZE any way even if it is not allocated */
    nr_sectors = block_mig_state->sectors_per_block;

    cur_sector &= ~((int64_t)block_mig_state->sectors_per_block -1);
    
    if(total_sectors - cur_sector < block_mig_state->sectors_per_block) {
        nr_sectors = (total_sectors - cur_sector);
    }
  
    bms->cur_sector = cur_sector + nr_sectors;
    blk->sector = cur_sector;
    blk->bmds = bms;
    blk->next = NULL;
  
    blk->iov.iov_base = blk->buf;
    blk->iov.iov_len = nr_sectors * SECTOR_SIZE;
    qemu_iovec_init_external(&blk->qiov, &blk->iov, 1);
  
    blk->aiocb = bdrv_aio_readv(bs, cur_sector, &blk->qiov,
                                nr_sectors, blk_mig_read_cb, blk);
  
    if(!blk->aiocb) {
        printf("Error reading sector %" PRId64 "\n", cur_sector);
        qemu_free(blk->buf);
        qemu_free(blk);
        return 0;
    }

    bdrv_reset_dirty(bms->bs, cur_sector, nr_sectors);
    block_mig_state->submitted++;
  
    return (bms->cur_sector >= total_sectors);
}

static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
{ 
    int len, nr_sectors;
    int64_t total_sectors = bmds->total_sectors, cur_sector = 0;
    uint8_t *tmp_buf = NULL;
    BlockDriverState *bs = bmds->bs;

    tmp_buf = qemu_malloc(BLOCK_SIZE);
  
    cur_sector = bmds->cur_sector;
    
    if(bmds->shared_base) {
        while(cur_sector < bmds->total_sectors && 
              !bdrv_is_allocated(bmds->bs, cur_sector, 
                                 MAX_IS_ALLOCATED_SEARCH, &nr_sectors)) {
            cur_sector += nr_sectors;
        }
    }
    
    if(cur_sector >= total_sectors) {
        bmds->cur_sector = total_sectors;
        qemu_free(tmp_buf);
        return 1;
    }
    
    if(cur_sector >= block_mig_state->print_completion) {
        printf("Completed %" PRId64 " %%\r", cur_sector * 100 / total_sectors);
        fflush(stdout);
        block_mig_state->print_completion += 
            (block_mig_state->sectors_per_block * 10000);
    }
    
    cur_sector &= ~((int64_t)block_mig_state->sectors_per_block -1);
        
    /* we going to transfer 
       BLOCK_SIZE 
       any way even if it is not allocated */
    nr_sectors = block_mig_state->sectors_per_block;
  
    if(total_sectors - cur_sector < block_mig_state->sectors_per_block) {
        nr_sectors = (total_sectors - cur_sector);
    }
  
    if(bdrv_read(bs, cur_sector, tmp_buf, nr_sectors) < 0) {
        printf("Error reading sector %" PRId64 "\n", cur_sector);
    }

    bdrv_reset_dirty(bs, cur_sector, nr_sectors);
  
    /* Device name */
    qemu_put_be64(f,(cur_sector << SECTOR_BITS) | BLK_MIG_FLAG_DEVICE_BLOCK);
  
    len = strlen(bs->device_name);
    qemu_put_byte(f, len);
    qemu_put_buffer(f, (uint8_t *)bs->device_name, len);
  
    qemu_put_buffer(f, tmp_buf, 
                    BLOCK_SIZE);
    
    bmds->cur_sector = cur_sector + block_mig_state->sectors_per_block;
  
    qemu_free(tmp_buf);
  
    return (bmds->cur_sector >= total_sectors);
}

static void send_blk(QEMUFile *f, BlkMigBlock * blk)
{
    int len;
  
    /* Device name */ 
    qemu_put_be64(f,(blk->sector << SECTOR_BITS) | BLK_MIG_FLAG_DEVICE_BLOCK);
  
    len = strlen(blk->bmds->bs->device_name);
    qemu_put_byte(f, len);
    qemu_put_buffer(f, (uint8_t *)blk->bmds->bs->device_name, len);
  
    qemu_put_buffer(f, blk->buf, 
                    BLOCK_SIZE);
  
    return;
}

static void blk_mig_save_dev_info(QEMUFile *f, BlkMigDevState *bmds)
{
}

static void set_dirty_tracking(int enable)
{
    BlkMigDevState *bmds;
    for(bmds = block_mig_state->bmds_first; bmds != NULL; bmds = bmds->next) {
        bdrv_set_dirty_tracking(bmds->bs,enable);
    }
    
    return;
}

static void init_blk_migration(QEMUFile *f)
{
    BlkMigDevState **pbmds, *bmds;
    BlockDriverState *bs;
    
    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
        if(bs->type == BDRV_TYPE_HD) {
            bmds = qemu_mallocz(sizeof(BlkMigDevState));
            bmds->bs = bs;
            bmds->bulk_completed = 0;
            bmds->total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
            bmds->shared_base = block_mig_state->shared_base;
	          
            if(bmds->shared_base) {
                printf("Start migration for %s with shared base image\n", 
                       bs->device_name);
            } else {
                printf("Start full migration for %s\n", bs->device_name);
            }
      
            /* insert at the end */
            pbmds = &block_mig_state->bmds_first;
            while (*pbmds != NULL)
                pbmds = &(*pbmds)->next;
            *pbmds = bmds;
      
            blk_mig_save_dev_info(f, bmds);
	    
        }
    } 
    
    block_mig_state->sectors_per_block = bdrv_get_sectors_per_chunk();
    
    return;
}

static int blk_mig_save_bulked_block(QEMUFile *f, int is_async)
{
    BlkMigDevState *bmds;

    for (bmds = block_mig_state->bmds_first; bmds != NULL; bmds = bmds->next) {
        if(bmds->bulk_completed == 0) {
            if(is_async) {
                if(mig_read_device_bulk(f, bmds) == 1) {
                    /* completed bulk section for this device */
                    bmds->bulk_completed = 1;
                }
            } else {
                if(mig_save_device_bulk(f,bmds) == 1) {
                    /* completed bulk section for this device */
                    bmds->bulk_completed = 1;
                }
            }
            return 1;
        }
    }
  
    /* we reached here means bulk is completed */
    block_mig_state->bulk_completed = 1;
  
    return 0;
    
}

#define MAX_NUM_BLOCKS 4

static void blk_mig_save_dirty_blocks(QEMUFile *f)
{
    BlkMigDevState *bmds;
    uint8_t buf[BLOCK_SIZE];
    int64_t sector;
    int len;
    
    for(bmds = block_mig_state->bmds_first; bmds != NULL; bmds = bmds->next) {
        for(sector = 0; sector < bmds->cur_sector;) {
	    
            if(bdrv_get_dirty(bmds->bs,sector)) {
		
                if(bdrv_read(bmds->bs, sector, buf, 
                             block_mig_state->sectors_per_block) < 0) {
                }
		
                /* device name */
                qemu_put_be64(f,(sector << SECTOR_BITS) 
                              | BLK_MIG_FLAG_DEVICE_BLOCK);
	
                len = strlen(bmds->bs->device_name);
	
                qemu_put_byte(f, len);
                qemu_put_buffer(f, (uint8_t *)bmds->bs->device_name, len);
	
                qemu_put_buffer(f, buf, 
                                (block_mig_state->sectors_per_block * 
                                 SECTOR_SIZE));
		
                bdrv_reset_dirty(bmds->bs, sector, 
                                 block_mig_state->sectors_per_block);
	
                sector += block_mig_state->sectors_per_block;
            } else {
                /* sector is clean */
                sector += block_mig_state->sectors_per_block;
            }  
        }
    }
    
    return;
}

static void flush_blks(QEMUFile* f)
{
    BlkMigBlock *blk, *tmp;
    
    dprintf("%s Enter submitted %d read_done %d transfered\n", __FUNCTION__, 
            submitted, read_done, transfered);
  
    for(blk = block_mig_state->first_blk; 
        blk != NULL && !qemu_file_rate_limit(f); blk = tmp) {
        send_blk(f, blk);
    
        tmp = blk->next;
        qemu_free(blk->buf);
        qemu_free(blk);
    
        block_mig_state->read_done--;
        block_mig_state->transferred++;
        assert(block_mig_state->read_done >= 0);
    }
    block_mig_state->first_blk = blk;
  
    if(block_mig_state->first_blk == NULL) {
        block_mig_state->last_blk = NULL;
    }

    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;
}

static int is_stage2_completed(void)
{
    BlkMigDevState *bmds;
  
    if(block_mig_state->submitted > 0) {
        return 0;
    }
  
    for (bmds = block_mig_state->bmds_first; bmds != NULL; bmds = bmds->next) {
        if(bmds->bulk_completed == 0) {
            return 0;
        }
    }
    
    return 1;
}

static int block_save_live(QEMUFile *f, int stage, void *opaque)
{
    int ret = 1;
    
    dprintf("Enter save live stage %d submitted %d transferred %d\n", stage, 
            submitted, transferred);
  
    if(block_mig_state->blk_enable != 1) {
        /* no need to migrate storage */
    
        qemu_put_be64(f,BLK_MIG_FLAG_EOS);
        return 1;
    }
  
    if(stage == 1) {
        init_blk_migration(f);
	
        /* start track dirty blocks */
        set_dirty_tracking(1);
	
    }

    flush_blks(f);
  
    /* control the rate of transfer */
    while ((block_mig_state->submitted + block_mig_state->read_done) * 
           (BLOCK_SIZE) < 
           (qemu_file_get_rate_limit(f))) {
	
        ret = blk_mig_save_bulked_block(f, 1);
	
        if (ret == 0) /* no more bulk blocks for now*/
            break;
    }
  
    flush_blks(f);
    
    if(stage == 3) {
	
        while(blk_mig_save_bulked_block(f, 0) != 0);
	
        blk_mig_save_dirty_blocks(f);
	
        /* stop track dirty blocks */
        set_dirty_tracking(0);;
	
        printf("\nBlock migration completed\n");  
    }
  
    qemu_put_be64(f,BLK_MIG_FLAG_EOS);
  
    return ((stage == 2) && is_stage2_completed());
}

static int block_load(QEMUFile *f, void *opaque, int version_id)
{
    int len, flags;
    char device_name[256];
    int64_t addr;
    BlockDriverState *bs;
    uint8_t *buf;
    
    block_mig_state->sectors_per_block = bdrv_get_sectors_per_chunk();
    buf = qemu_malloc(BLOCK_SIZE);
    
    do {
    
        addr = qemu_get_be64(f);
    
        flags = addr & ~SECTOR_MASK;
        addr &= SECTOR_MASK;
    
        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);
      
            qemu_get_buffer(f, buf, 
                            BLOCK_SIZE);
            if(bs != NULL) {
	
                bdrv_write(bs, (addr >> SECTOR_BITS), 
                           buf, block_mig_state->sectors_per_block);
            } else {
                printf("Error unknown block device %s\n", device_name);
            }
        } else if(flags & BLK_MIG_FLAG_EOS) {
	    
        } else {
            printf("Unknown flags\n");
        }
    } while(!(flags & BLK_MIG_FLAG_EOS));
  
    qemu_free(buf);

    return 0;
}

static void block_set_params(int blk_enable, int shared_base, void *opaque)
{
    assert(opaque == block_mig_state);

    block_mig_state->blk_enable = blk_enable;
    block_mig_state->shared_base = shared_base;
  
    /* shared base means that blk_enable = 1 */
    block_mig_state->blk_enable |= shared_base;
  
    return;
}

void blk_mig_info(void)
{
    BlockDriverState *bs;
  
    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
        printf("Device %s\n", bs->device_name);
        if(bs->type == BDRV_TYPE_HD) {
            printf("device %s format %s\n", 
                   bs->device_name, bs->drv->format_name);
        }
    }
}

void blk_mig_init(void)
{ 
    
    block_mig_state = qemu_mallocz(sizeof(BlkMigState));
    
    register_savevm_live("block", 0, 1, block_set_params, block_save_live, 
                         NULL, block_load, block_mig_state);

 
}
Commit	Line	Data
c163b5ca	1	/*
	2	* QEMU live block migration
	3	*
	4	* Copyright IBM, Corp. 2009
	5	*
	6	* Authors:
	7	* Liran Schour <lirans@il.ibm.com>
	8	*
	9	* This work is licensed under the terms of the GNU GPL, version 2. See
	10	* the COPYING file in the top-level directory.
	11	*
	12	*/
	13
	14	#include "qemu-common.h"
	15	#include "block_int.h"
	16	#include "hw/hw.h"
	17	#include "block-migration.h"
	18	#include <assert.h>
	19	#include <pthread.h>
	20
	21	#define SECTOR_BITS 9
	22	#define SECTOR_SIZE (1 << SECTOR_BITS)
	23	#define SECTOR_MASK ~(SECTOR_SIZE - 1);
	24
	25	#define BLOCK_SIZE (block_mig_state->sectors_per_block << SECTOR_BITS)
	26
	27	#define BLK_MIG_FLAG_DEVICE_BLOCK 0x01
	28	#define BLK_MIG_FLAG_EOS 0x02
	29
	30	#define MAX_IS_ALLOCATED_SEARCH 65536
	31	#define MAX_BLOCKS_READ 10000
	32	#define BLOCKS_READ_CHANGE 100
	33	#define INITIAL_BLOCKS_READ 100
	34
	35	//#define DEBUG_BLK_MIGRATION
	36
	37	#ifdef DEBUG_BLK_MIGRATION
	38	#define dprintf(fmt, ...) \
	39	do { printf("blk_migration: " fmt, ## __VA_ARGS__); } while (0)
	40	#else
	41	#define dprintf(fmt, ...) \
	42	do { } while (0)
	43	#endif
	44
	45	typedef struct BlkMigBlock {
	46	uint8_t *buf;
	47	BlkMigDevState *bmds;
	48	int64_t sector;
	49	struct iovec iov;
	50	QEMUIOVector qiov;
	51	BlockDriverAIOCB *aiocb;
	52	int ret;
	53	struct BlkMigBlock *next;
	54	} BlkMigBlock;
	55
	56	typedef struct BlkMigState {
	57	int bulk_completed;
	58	int blk_enable;
	59	int shared_base;
	60	int no_dirty;
	61	QEMUFile *load_file;
	62	BlkMigDevState *bmds_first;
	63	int sectors_per_block;
	64	BlkMigBlock *first_blk;
65	BlkMigBlock *last_blk;
66	int submitted;
67	int read_done;
68	int transferred;
69	int64_t print_completion;
70	} BlkMigState;
71
72	static BlkMigState *block_mig_state = NULL;
73
74	static void blk_mig_read_cb(void *opaque, int ret)
75	{
76	BlkMigBlock *blk = opaque;
77
78	blk->ret = ret;
79
80	/* insert at the end */
81	if(block_mig_state->last_blk == NULL) {
82	block_mig_state->first_blk = blk;
83	block_mig_state->last_blk = blk;
84	} else {
85	block_mig_state->last_blk->next = blk;
86	block_mig_state->last_blk = blk;
87	}
88
89	block_mig_state->submitted--;
90	block_mig_state->read_done++;
91	assert(block_mig_state->submitted >= 0);
92
93	return;
94	}
95
96	static int mig_read_device_bulk(QEMUFile f, BlkMigDevState bms)
97	{
98	int nr_sectors;
99	int64_t total_sectors, cur_sector = 0;
100	BlockDriverState *bs = bms->bs;
101	BlkMigBlock *blk;
102
103	blk = qemu_malloc(sizeof(BlkMigBlock));
104	blk->buf = qemu_malloc(BLOCK_SIZE);
105
106	cur_sector = bms->cur_sector;
107	total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
108
109	if(bms->shared_base) {
110	while(cur_sector < bms->total_sectors &&
111	!bdrv_is_allocated(bms->bs, cur_sector,
112	MAX_IS_ALLOCATED_SEARCH, &nr_sectors)) {
113	cur_sector += nr_sectors;
114	}
115	}
116
117	if(cur_sector >= total_sectors) {
118	bms->cur_sector = total_sectors;
119	qemu_free(blk->buf);
120	qemu_free(blk);
121	return 1;
122	}
123
124	if(cur_sector >= block_mig_state->print_completion) {
125	printf("Completed %" PRId64 " %%\r", cur_sector * 100 / total_sectors);
126	fflush(stdout);
127	block_mig_state->print_completion +=
128	(block_mig_state->sectors_per_block * 10000);
129	}
130
131	/* we going to transfder BLOCK_SIZE any way even if it is not allocated */
132	nr_sectors = block_mig_state->sectors_per_block;
133
134	cur_sector &= ~((int64_t)block_mig_state->sectors_per_block -1);
135
136	if(total_sectors - cur_sector < block_mig_state->sectors_per_block) {
137	nr_sectors = (total_sectors - cur_sector);
138	}
139
140	bms->cur_sector = cur_sector + nr_sectors;
141	blk->sector = cur_sector;
142	blk->bmds = bms;
143	blk->next = NULL;
144
145	blk->iov.iov_base = blk->buf;
146	blk->iov.iov_len = nr_sectors * SECTOR_SIZE;
147	qemu_iovec_init_external(&blk->qiov, &blk->iov, 1);
148
149	blk->aiocb = bdrv_aio_readv(bs, cur_sector, &blk->qiov,
150	nr_sectors, blk_mig_read_cb, blk);
151
152	if(!blk->aiocb) {
153	printf("Error reading sector %" PRId64 "\n", cur_sector);
154	qemu_free(blk->buf);
155	qemu_free(blk);
156	return 0;
157	}
158
159	bdrv_reset_dirty(bms->bs, cur_sector, nr_sectors);
160	block_mig_state->submitted++;
161
162	return (bms->cur_sector >= total_sectors);
163	}
164
165	static int mig_save_device_bulk(QEMUFile f, BlkMigDevState bmds)
166	{
167	int len, nr_sectors;
168	int64_t total_sectors = bmds->total_sectors, cur_sector = 0;
169	uint8_t *tmp_buf = NULL;
170	BlockDriverState *bs = bmds->bs;
171
172	tmp_buf = qemu_malloc(BLOCK_SIZE);
173
174	cur_sector = bmds->cur_sector;
175
176	if(bmds->shared_base) {
177	while(cur_sector < bmds->total_sectors &&
178	!bdrv_is_allocated(bmds->bs, cur_sector,
179	MAX_IS_ALLOCATED_SEARCH, &nr_sectors)) {
180	cur_sector += nr_sectors;
181	}
182	}
183
184	if(cur_sector >= total_sectors) {
185	bmds->cur_sector = total_sectors;
186	qemu_free(tmp_buf);
187	return 1;
188	}
189
190	if(cur_sector >= block_mig_state->print_completion) {
191	printf("Completed %" PRId64 " %%\r", cur_sector * 100 / total_sectors);
192	fflush(stdout);
193	block_mig_state->print_completion +=
194	(block_mig_state->sectors_per_block * 10000);
195	}
196
197	cur_sector &= ~((int64_t)block_mig_state->sectors_per_block -1);
198
199	/* we going to transfer
200	BLOCK_SIZE
201	any way even if it is not allocated */
202	nr_sectors = block_mig_state->sectors_per_block;
203
204	if(total_sectors - cur_sector < block_mig_state->sectors_per_block) {
205	nr_sectors = (total_sectors - cur_sector);
206	}
207
208	if(bdrv_read(bs, cur_sector, tmp_buf, nr_sectors) < 0) {
209	printf("Error reading sector %" PRId64 "\n", cur_sector);
210	}
211
212	bdrv_reset_dirty(bs, cur_sector, nr_sectors);
213
214	/* Device name */
215	qemu_put_be64(f,(cur_sector << SECTOR_BITS) \| BLK_MIG_FLAG_DEVICE_BLOCK);
216
217	len = strlen(bs->device_name);
218	qemu_put_byte(f, len);
219	qemu_put_buffer(f, (uint8_t *)bs->device_name, len);
220
221	qemu_put_buffer(f, tmp_buf,
222	BLOCK_SIZE);
223
224	bmds->cur_sector = cur_sector + block_mig_state->sectors_per_block;
225
226	qemu_free(tmp_buf);
227
228	return (bmds->cur_sector >= total_sectors);
229	}
230
231	static void send_blk(QEMUFile f, BlkMigBlock blk)
232	{
233	int len;
234
235	/* Device name */
236	qemu_put_be64(f,(blk->sector << SECTOR_BITS) \| BLK_MIG_FLAG_DEVICE_BLOCK);
237
238	len = strlen(blk->bmds->bs->device_name);
239	qemu_put_byte(f, len);
240	qemu_put_buffer(f, (uint8_t *)blk->bmds->bs->device_name, len);
241
242	qemu_put_buffer(f, blk->buf,
243	BLOCK_SIZE);
244
245	return;
246	}
247
248	static void blk_mig_save_dev_info(QEMUFile f, BlkMigDevState bmds)
249	{
250	}
251
252	static void set_dirty_tracking(int enable)
253	{
254	BlkMigDevState *bmds;
255	for(bmds = block_mig_state->bmds_first; bmds != NULL; bmds = bmds->next) {
256	bdrv_set_dirty_tracking(bmds->bs,enable);
257	}
258
259	return;
260	}
261
262	static void init_blk_migration(QEMUFile *f)
263	{
264	BlkMigDevState *pbmds, bmds;
265	BlockDriverState *bs;
266
267	for (bs = bdrv_first; bs != NULL; bs = bs->next) {
268	if(bs->type == BDRV_TYPE_HD) {
269	bmds = qemu_mallocz(sizeof(BlkMigDevState));
270	bmds->bs = bs;
271	bmds->bulk_completed = 0;
272	bmds->total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
273	bmds->shared_base = block_mig_state->shared_base;
274
275	if(bmds->shared_base) {
276	printf("Start migration for %s with shared base image\n",
277	bs->device_name);
278	} else {
279	printf("Start full migration for %s\n", bs->device_name);
280	}
281
282	/* insert at the end */
283	pbmds = &block_mig_state->bmds_first;
284	while (*pbmds != NULL)
285	pbmds = &(*pbmds)->next;
286	*pbmds = bmds;
287
288	blk_mig_save_dev_info(f, bmds);
289
290	}
291	}
292
293	block_mig_state->sectors_per_block = bdrv_get_sectors_per_chunk();
294
295	return;
296	}
297
298	static int blk_mig_save_bulked_block(QEMUFile *f, int is_async)
299	{
300	BlkMigDevState *bmds;
301
302	for (bmds = block_mig_state->bmds_first; bmds != NULL; bmds = bmds->next) {
303	if(bmds->bulk_completed == 0) {
304	if(is_async) {
305	if(mig_read_device_bulk(f, bmds) == 1) {
306	/* completed bulk section for this device */
307	bmds->bulk_completed = 1;
308	}
309	} else {
310	if(mig_save_device_bulk(f,bmds) == 1) {
311	/* completed bulk section for this device */
312	bmds->bulk_completed = 1;
313	}
314	}
315	return 1;
316	}
317	}
318
319	/* we reached here means bulk is completed */
320	block_mig_state->bulk_completed = 1;
321
322	return 0;
323
324	}
325
326	#define MAX_NUM_BLOCKS 4
327
328	static void blk_mig_save_dirty_blocks(QEMUFile *f)
329	{
330	BlkMigDevState *bmds;
331	uint8_t buf[BLOCK_SIZE];
332	int64_t sector;
333	int len;
334
335	for(bmds = block_mig_state->bmds_first; bmds != NULL; bmds = bmds->next) {
336	for(sector = 0; sector < bmds->cur_sector;) {
337
338	if(bdrv_get_dirty(bmds->bs,sector)) {
339
340	if(bdrv_read(bmds->bs, sector, buf,
341	block_mig_state->sectors_per_block) < 0) {
342	}
343
344	/* device name */
345	qemu_put_be64(f,(sector << SECTOR_BITS)
346	\| BLK_MIG_FLAG_DEVICE_BLOCK);
347
348	len = strlen(bmds->bs->device_name);
349
350	qemu_put_byte(f, len);
351	qemu_put_buffer(f, (uint8_t *)bmds->bs->device_name, len);
352
353	qemu_put_buffer(f, buf,
354	(block_mig_state->sectors_per_block *
355	SECTOR_SIZE));
356
357	bdrv_reset_dirty(bmds->bs, sector,
358	block_mig_state->sectors_per_block);
359
360	sector += block_mig_state->sectors_per_block;
361	} else {
362	/* sector is clean */
363	sector += block_mig_state->sectors_per_block;
364	}
365	}
366	}
367
368	return;
369	}
370
371	static void flush_blks(QEMUFile* f)
372	{
373	BlkMigBlock blk, tmp;
374
375	dprintf("%s Enter submitted %d read_done %d transfered\n", __FUNCTION__,
376	submitted, read_done, transfered);
377
378	for(blk = block_mig_state->first_blk;
379	blk != NULL && !qemu_file_rate_limit(f); blk = tmp) {
380	send_blk(f, blk);
381
382	tmp = blk->next;
383	qemu_free(blk->buf);
384	qemu_free(blk);
385
386	block_mig_state->read_done--;
387	block_mig_state->transferred++;
388	assert(block_mig_state->read_done >= 0);
389	}
390	block_mig_state->first_blk = blk;
391
392	if(block_mig_state->first_blk == NULL) {
393	block_mig_state->last_blk = NULL;
394	}
395
396	dprintf("%s Exit submitted %d read_done %d transferred%d\n", __FUNCTION__,
397	block_mig_state->submitted, block_mig_state->read_done,
398	block_mig_state->transferred);
399
400	return;
401	}
402
403	static int is_stage2_completed(void)
404	{
405	BlkMigDevState *bmds;
406
407	if(block_mig_state->submitted > 0) {
408	return 0;
409	}
410
411	for (bmds = block_mig_state->bmds_first; bmds != NULL; bmds = bmds->next) {
412	if(bmds->bulk_completed == 0) {
413	return 0;
414	}
415	}
416
417	return 1;
418	}
419
420	static int block_save_live(QEMUFile f, int stage, void opaque)
421	{
422	int ret = 1;
423
424	dprintf("Enter save live stage %d submitted %d transferred %d\n", stage,
425	submitted, transferred);
426
427	if(block_mig_state->blk_enable != 1) {
428	/* no need to migrate storage */
429
430	qemu_put_be64(f,BLK_MIG_FLAG_EOS);
431	return 1;
432	}
433
434	if(stage == 1) {
435	init_blk_migration(f);
436
437	/* start track dirty blocks */
438	set_dirty_tracking(1);
439
440	}
441
442	flush_blks(f);
443
444	/* control the rate of transfer */
445	while ((block_mig_state->submitted + block_mig_state->read_done) *
446	(BLOCK_SIZE) <
447	(qemu_file_get_rate_limit(f))) {
448
449	ret = blk_mig_save_bulked_block(f, 1);
450
451	if (ret == 0) /* no more bulk blocks for now*/
452	break;
453	}
454
455	flush_blks(f);
456
457	if(stage == 3) {
458
459	while(blk_mig_save_bulked_block(f, 0) != 0);
460
461	blk_mig_save_dirty_blocks(f);
462
463	/* stop track dirty blocks */
464	set_dirty_tracking(0);;
465
466	printf("\nBlock migration completed\n");
467	}
468
469	qemu_put_be64(f,BLK_MIG_FLAG_EOS);
470
471	return ((stage == 2) && is_stage2_completed());
472	}
473
474	static int block_load(QEMUFile f, void opaque, int version_id)
475	{
476	int len, flags;
477	char device_name[256];
478	int64_t addr;
479	BlockDriverState *bs;
480	uint8_t *buf;
481
482	block_mig_state->sectors_per_block = bdrv_get_sectors_per_chunk();
483	buf = qemu_malloc(BLOCK_SIZE);
484
485	do {
486
487	addr = qemu_get_be64(f);
488
489	flags = addr & ~SECTOR_MASK;
490	addr &= SECTOR_MASK;
491
492	if(flags & BLK_MIG_FLAG_DEVICE_BLOCK) {
493
494	/* get device name */
495	len = qemu_get_byte(f);
496
497	qemu_get_buffer(f, (uint8_t *)device_name, len);
498	device_name[len] = '\0';
499
500	bs = bdrv_find(device_name);
501
502	qemu_get_buffer(f, buf,
503	BLOCK_SIZE);
504	if(bs != NULL) {
505
506	bdrv_write(bs, (addr >> SECTOR_BITS),
507	buf, block_mig_state->sectors_per_block);
508	} else {
509	printf("Error unknown block device %s\n", device_name);
510	}
511	} else if(flags & BLK_MIG_FLAG_EOS) {
512
513	} else {
514	printf("Unknown flags\n");
515	}
516	} while(!(flags & BLK_MIG_FLAG_EOS));
517
518	qemu_free(buf);
519
520	return 0;
521	}
522
523	static void block_set_params(int blk_enable, int shared_base, void *opaque)
524	{
525	assert(opaque == block_mig_state);
526
527	block_mig_state->blk_enable = blk_enable;
528	block_mig_state->shared_base = shared_base;
529
530	/* shared base means that blk_enable = 1 */
531	block_mig_state->blk_enable \|= shared_base;
532
533	return;
534	}
535
536	void blk_mig_info(void)
537	{
538	BlockDriverState *bs;
539
540	for (bs = bdrv_first; bs != NULL; bs = bs->next) {
541	printf("Device %s\n", bs->device_name);
542	if(bs->type == BDRV_TYPE_HD) {
543	printf("device %s format %s\n",
544	bs->device_name, bs->drv->format_name);
545	}
546	}
547	}
548
549	void blk_mig_init(void)
550	{
551
552	block_mig_state = qemu_mallocz(sizeof(BlkMigState));
553
554	register_savevm_live("block", 0, 1, block_set_params, block_save_live,
555	NULL, block_load, block_mig_state);
556
557
558	}