diff options
Diffstat (limited to 'block-migration.c')
| -rw-r--r-- | block-migration.c | 558 |
1 files changed, 558 insertions, 0 deletions
diff --git a/block-migration.c b/block-migration.c new file mode 100644 index 0000000000..4b4eddf62a --- /dev/null +++ b/block-migration.c @@ -0,0 +1,558 @@ +/* + * 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); + + +} |