+++ /dev/null
-/*
- * 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.
- *
- * Contributions after 2012-01-13 are licensed under the terms of the
- * GNU GPL, version 2 or (at your option) any later version.
- */
-
-#include "qemu/osdep.h"
-#include "qapi/error.h"
-#include "qemu/error-report.h"
-#include "qemu/main-loop.h"
-#include "qemu/cutils.h"
-#include "qemu/queue.h"
-#include "block.h"
-#include "block/dirty-bitmap.h"
-#include "migration/misc.h"
-#include "migration.h"
-#include "migration/register.h"
-#include "qemu-file.h"
-#include "migration/vmstate.h"
-#include "sysemu/block-backend.h"
-#include "trace.h"
-
-#define BLK_MIG_BLOCK_SIZE (1ULL << 20)
-#define BDRV_SECTORS_PER_DIRTY_CHUNK (BLK_MIG_BLOCK_SIZE >> BDRV_SECTOR_BITS)
-
-#define BLK_MIG_FLAG_DEVICE_BLOCK 0x01
-#define BLK_MIG_FLAG_EOS 0x02
-#define BLK_MIG_FLAG_PROGRESS 0x04
-#define BLK_MIG_FLAG_ZERO_BLOCK 0x08
-
-#define MAX_IS_ALLOCATED_SEARCH (65536 * BDRV_SECTOR_SIZE)
-
-#define MAX_IO_BUFFERS 512
-#define MAX_PARALLEL_IO 16
-
-typedef struct BlkMigDevState {
- /* Written during setup phase. Can be read without a lock. */
- BlockBackend *blk;
- char *blk_name;
- int shared_base;
- int64_t total_sectors;
- QSIMPLEQ_ENTRY(BlkMigDevState) entry;
- Error *blocker;
-
- /* Only used by migration thread. Does not need a lock. */
- int bulk_completed;
- int64_t cur_sector;
- int64_t cur_dirty;
-
- /* Data in the aio_bitmap is protected by block migration lock.
- * Allocation and free happen during setup and cleanup respectively.
- */
- unsigned long *aio_bitmap;
-
- /* Protected by block migration lock. */
- int64_t completed_sectors;
-
- /* During migration this is protected by iothread lock / AioContext.
- * Allocation and free happen during setup and cleanup respectively.
- */
- BdrvDirtyBitmap *dirty_bitmap;
-} BlkMigDevState;
-
-typedef struct BlkMigBlock {
- /* Only used by migration thread. */
- uint8_t *buf;
- BlkMigDevState *bmds;
- int64_t sector;
- int nr_sectors;
- QEMUIOVector qiov;
- BlockAIOCB *aiocb;
-
- /* Protected by block migration lock. */
- int ret;
- QSIMPLEQ_ENTRY(BlkMigBlock) entry;
-} BlkMigBlock;
-
-typedef struct BlkMigState {
- QSIMPLEQ_HEAD(, BlkMigDevState) bmds_list;
- int64_t total_sector_sum;
- bool zero_blocks;
-
- /* Protected by lock. */
- QSIMPLEQ_HEAD(, BlkMigBlock) blk_list;
- int submitted;
- int read_done;
-
- /* Only used by migration thread. Does not need a lock. */
- int transferred;
- int prev_progress;
- int bulk_completed;
-
- /* Lock must be taken _inside_ the iothread lock and any AioContexts. */
- QemuMutex lock;
-} BlkMigState;
-
-static BlkMigState block_mig_state;
-
-static void blk_mig_lock(void)
-{
- qemu_mutex_lock(&block_mig_state.lock);
-}
-
-static void blk_mig_unlock(void)
-{
- qemu_mutex_unlock(&block_mig_state.lock);
-}
-
-/* Must run outside of the iothread lock during the bulk phase,
- * or the VM will stall.
- */
-
-static void blk_send(QEMUFile *f, BlkMigBlock * blk)
-{
- int len;
- uint64_t flags = BLK_MIG_FLAG_DEVICE_BLOCK;
-
- if (block_mig_state.zero_blocks &&
- buffer_is_zero(blk->buf, BLK_MIG_BLOCK_SIZE)) {
- flags |= BLK_MIG_FLAG_ZERO_BLOCK;
- }
-
- /* sector number and flags */
- qemu_put_be64(f, (blk->sector << BDRV_SECTOR_BITS)
- | flags);
-
- /* device name */
- len = strlen(blk->bmds->blk_name);
- qemu_put_byte(f, len);
- qemu_put_buffer(f, (uint8_t *) blk->bmds->blk_name, len);
-
- /* if a block is zero we need to flush here since the network
- * bandwidth is now a lot higher than the storage device bandwidth.
- * thus if we queue zero blocks we slow down the migration */
- if (flags & BLK_MIG_FLAG_ZERO_BLOCK) {
- qemu_fflush(f);
- return;
- }
-
- qemu_put_buffer(f, blk->buf, BLK_MIG_BLOCK_SIZE);
-}
-
-int blk_mig_active(void)
-{
- return !QSIMPLEQ_EMPTY(&block_mig_state.bmds_list);
-}
-
-int blk_mig_bulk_active(void)
-{
- return blk_mig_active() && !block_mig_state.bulk_completed;
-}
-
-uint64_t blk_mig_bytes_transferred(void)
-{
- BlkMigDevState *bmds;
- uint64_t sum = 0;
-
- blk_mig_lock();
- QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
- sum += bmds->completed_sectors;
- }
- blk_mig_unlock();
- return sum << BDRV_SECTOR_BITS;
-}
-
-uint64_t blk_mig_bytes_remaining(void)
-{
- return blk_mig_bytes_total() - blk_mig_bytes_transferred();
-}
-
-uint64_t blk_mig_bytes_total(void)
-{
- BlkMigDevState *bmds;
- uint64_t sum = 0;
-
- QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
- sum += bmds->total_sectors;
- }
- return sum << BDRV_SECTOR_BITS;
-}
-
-
-/* Called with migration lock held. */
-
-static int bmds_aio_inflight(BlkMigDevState *bmds, int64_t sector)
-{
- int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
-
- if (sector < blk_nb_sectors(bmds->blk)) {
- return !!(bmds->aio_bitmap[chunk / (sizeof(unsigned long) * 8)] &
- (1UL << (chunk % (sizeof(unsigned long) * 8))));
- } else {
- return 0;
- }
-}
-
-/* Called with migration lock held. */
-
-static void bmds_set_aio_inflight(BlkMigDevState *bmds, int64_t sector_num,
- int nb_sectors, int set)
-{
- int64_t start, end;
- unsigned long val, idx, bit;
-
- start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
- end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
-
- for (; start <= end; start++) {
- idx = start / (sizeof(unsigned long) * 8);
- bit = start % (sizeof(unsigned long) * 8);
- val = bmds->aio_bitmap[idx];
- if (set) {
- val |= 1UL << bit;
- } else {
- val &= ~(1UL << bit);
- }
- bmds->aio_bitmap[idx] = val;
- }
-}
-
-static void alloc_aio_bitmap(BlkMigDevState *bmds)
-{
- BlockBackend *bb = bmds->blk;
- int64_t bitmap_size;
-
- bitmap_size = blk_nb_sectors(bb) + BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
- bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
-
- bmds->aio_bitmap = g_malloc0(bitmap_size);
-}
-
-/* Never hold migration lock when yielding to the main loop! */
-
-static void blk_mig_read_cb(void *opaque, int ret)
-{
- BlkMigBlock *blk = opaque;
-
- blk_mig_lock();
- blk->ret = ret;
-
- QSIMPLEQ_INSERT_TAIL(&block_mig_state.blk_list, blk, entry);
- bmds_set_aio_inflight(blk->bmds, blk->sector, blk->nr_sectors, 0);
-
- block_mig_state.submitted--;
- block_mig_state.read_done++;
- assert(block_mig_state.submitted >= 0);
- blk_mig_unlock();
-}
-
-/* Called with no lock taken. */
-
-static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
-{
- int64_t total_sectors = bmds->total_sectors;
- int64_t cur_sector = bmds->cur_sector;
- BlockBackend *bb = bmds->blk;
- BlkMigBlock *blk;
- int nr_sectors;
- int64_t count;
-
- if (bmds->shared_base) {
- qemu_mutex_lock_iothread();
- aio_context_acquire(blk_get_aio_context(bb));
- /* Skip unallocated sectors; intentionally treats failure or
- * partial sector as an allocated sector */
- while (cur_sector < total_sectors &&
- !bdrv_is_allocated(blk_bs(bb), cur_sector * BDRV_SECTOR_SIZE,
- MAX_IS_ALLOCATED_SEARCH, &count)) {
- if (count < BDRV_SECTOR_SIZE) {
- break;
- }
- cur_sector += count >> BDRV_SECTOR_BITS;
- }
- aio_context_release(blk_get_aio_context(bb));
- qemu_mutex_unlock_iothread();
- }
-
- if (cur_sector >= total_sectors) {
- bmds->cur_sector = bmds->completed_sectors = total_sectors;
- return 1;
- }
-
- bmds->completed_sectors = cur_sector;
-
- cur_sector &= ~((int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK - 1);
-
- /* we are going to transfer a full block even if it is not allocated */
- nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
-
- if (total_sectors - cur_sector < BDRV_SECTORS_PER_DIRTY_CHUNK) {
- nr_sectors = total_sectors - cur_sector;
- }
-
- blk = g_new(BlkMigBlock, 1);
- blk->buf = g_malloc(BLK_MIG_BLOCK_SIZE);
- blk->bmds = bmds;
- blk->sector = cur_sector;
- blk->nr_sectors = nr_sectors;
-
- qemu_iovec_init_buf(&blk->qiov, blk->buf, nr_sectors * BDRV_SECTOR_SIZE);
-
- blk_mig_lock();
- block_mig_state.submitted++;
- blk_mig_unlock();
-
- /* We do not know if bs is under the main thread (and thus does
- * not acquire the AioContext when doing AIO) or rather under
- * dataplane. Thus acquire both the iothread mutex and the
- * AioContext.
- *
- * This is ugly and will disappear when we make bdrv_* thread-safe,
- * without the need to acquire the AioContext.
- */
- qemu_mutex_lock_iothread();
- aio_context_acquire(blk_get_aio_context(bmds->blk));
- bdrv_reset_dirty_bitmap(bmds->dirty_bitmap, cur_sector * BDRV_SECTOR_SIZE,
- nr_sectors * BDRV_SECTOR_SIZE);
- blk->aiocb = blk_aio_preadv(bb, cur_sector * BDRV_SECTOR_SIZE, &blk->qiov,
- 0, blk_mig_read_cb, blk);
- aio_context_release(blk_get_aio_context(bmds->blk));
- qemu_mutex_unlock_iothread();
-
- bmds->cur_sector = cur_sector + nr_sectors;
- return (bmds->cur_sector >= total_sectors);
-}
-
-/* Called with iothread lock taken. */
-
-static int set_dirty_tracking(void)
-{
- BlkMigDevState *bmds;
- int ret;
-
- QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
- bmds->dirty_bitmap = bdrv_create_dirty_bitmap(blk_bs(bmds->blk),
- BLK_MIG_BLOCK_SIZE,
- NULL, NULL);
- if (!bmds->dirty_bitmap) {
- ret = -errno;
- goto fail;
- }
- }
- return 0;
-
-fail:
- QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
- if (bmds->dirty_bitmap) {
- bdrv_release_dirty_bitmap(bmds->dirty_bitmap);
- }
- }
- return ret;
-}
-
-/* Called with iothread lock taken. */
-
-static void unset_dirty_tracking(void)
-{
- BlkMigDevState *bmds;
-
- QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
- bdrv_release_dirty_bitmap(bmds->dirty_bitmap);
- }
-}
-
-static int init_blk_migration(QEMUFile *f)
-{
- BlockDriverState *bs;
- BlkMigDevState *bmds;
- int64_t sectors;
- BdrvNextIterator it;
- int i, num_bs = 0;
- struct {
- BlkMigDevState *bmds;
- BlockDriverState *bs;
- } *bmds_bs;
- Error *local_err = NULL;
- int ret;
-
- 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();
-
- for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
- num_bs++;
- }
- bmds_bs = g_malloc0(num_bs * sizeof(*bmds_bs));
-
- for (i = 0, bs = bdrv_first(&it); bs; bs = bdrv_next(&it), i++) {
- if (bdrv_is_read_only(bs)) {
- continue;
- }
-
- sectors = bdrv_nb_sectors(bs);
- if (sectors <= 0) {
- ret = sectors;
- bdrv_next_cleanup(&it);
- goto out;
- }
-
- bmds = g_new0(BlkMigDevState, 1);
- bmds->blk = blk_new(qemu_get_aio_context(),
- BLK_PERM_CONSISTENT_READ, BLK_PERM_ALL);
- bmds->blk_name = g_strdup(bdrv_get_device_name(bs));
- bmds->bulk_completed = 0;
- bmds->total_sectors = sectors;
- bmds->completed_sectors = 0;
- bmds->shared_base = migrate_use_block_incremental();
-
- assert(i < num_bs);
- bmds_bs[i].bmds = bmds;
- bmds_bs[i].bs = bs;
-
- block_mig_state.total_sector_sum += sectors;
-
- if (bmds->shared_base) {
- trace_migration_block_init_shared(bdrv_get_device_name(bs));
- } else {
- trace_migration_block_init_full(bdrv_get_device_name(bs));
- }
-
- QSIMPLEQ_INSERT_TAIL(&block_mig_state.bmds_list, bmds, entry);
- }
-
- /* Can only insert new BDSes now because doing so while iterating block
- * devices may end up in a deadlock (iterating the new BDSes, too). */
- for (i = 0; i < num_bs; i++) {
- BlkMigDevState *bmds = bmds_bs[i].bmds;
- BlockDriverState *bs = bmds_bs[i].bs;
-
- if (bmds) {
- ret = blk_insert_bs(bmds->blk, bs, &local_err);
- if (ret < 0) {
- error_report_err(local_err);
- goto out;
- }
-
- alloc_aio_bitmap(bmds);
- error_setg(&bmds->blocker, "block device is in use by migration");
- bdrv_op_block_all(bs, bmds->blocker);
- }
- }
-
- ret = 0;
-out:
- g_free(bmds_bs);
- return ret;
-}
-
-/* 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);
- trace_migration_block_progression(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 and AioContext 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();
- blk_drain(bmds->blk);
- } else {
- blk_mig_unlock();
- }
- bdrv_dirty_bitmap_lock(bmds->dirty_bitmap);
- if (bdrv_dirty_bitmap_get_locked(bmds->dirty_bitmap,
- sector * BDRV_SECTOR_SIZE)) {
- if (total_sectors - sector < BDRV_SECTORS_PER_DIRTY_CHUNK) {
- nr_sectors = total_sectors - sector;
- } else {
- nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
- }
- bdrv_reset_dirty_bitmap_locked(bmds->dirty_bitmap,
- sector * BDRV_SECTOR_SIZE,
- nr_sectors * BDRV_SECTOR_SIZE);
- bdrv_dirty_bitmap_unlock(bmds->dirty_bitmap);
-
- blk = g_new(BlkMigBlock, 1);
- blk->buf = g_malloc(BLK_MIG_BLOCK_SIZE);
- blk->bmds = bmds;
- blk->sector = sector;
- blk->nr_sectors = nr_sectors;
-
- if (is_async) {
- qemu_iovec_init_buf(&blk->qiov, blk->buf,
- nr_sectors * BDRV_SECTOR_SIZE);
-
- blk->aiocb = blk_aio_preadv(bmds->blk,
- sector * BDRV_SECTOR_SIZE,
- &blk->qiov, 0, 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 = blk_pread(bmds->blk, sector * BDRV_SECTOR_SIZE,
- nr_sectors * BDRV_SECTOR_SIZE, blk->buf, 0);
- if (ret < 0) {
- goto error;
- }
- blk_send(f, blk);
-
- g_free(blk->buf);
- g_free(blk);
- }
-
- sector += nr_sectors;
- bmds->cur_dirty = sector;
- break;
- }
-
- bdrv_dirty_bitmap_unlock(bmds->dirty_bitmap);
- sector += BDRV_SECTORS_PER_DIRTY_CHUNK;
- bmds->cur_dirty = sector;
- }
-
- return (bmds->cur_dirty >= bmds->total_sectors);
-
-error:
- trace_migration_block_save_device_dirty(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) {
- aio_context_acquire(blk_get_aio_context(bmds->blk));
- ret = mig_save_device_dirty(f, bmds, is_async);
- aio_context_release(blk_get_aio_context(bmds->blk));
- if (ret <= 0) {
- break;
- }
- }
-
- return ret;
-}
-
-/* Called with no locks taken. */
-
-static int flush_blks(QEMUFile *f)
-{
- BlkMigBlock *blk;
- int ret = 0;
-
- trace_migration_block_flush_blks("Enter", 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();
-
- trace_migration_block_flush_blks("Exit", 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) {
- aio_context_acquire(blk_get_aio_context(bmds->blk));
- dirty += bdrv_get_dirty_count(bmds->dirty_bitmap);
- aio_context_release(blk_get_aio_context(bmds->blk));
- }
-
- return dirty;
-}
-
-
-
-/* Called with iothread lock taken. */
-static void block_migration_cleanup_bmds(void)
-{
- BlkMigDevState *bmds;
- AioContext *ctx;
-
- unset_dirty_tracking();
-
- while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != NULL) {
- QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry);
- bdrv_op_unblock_all(blk_bs(bmds->blk), bmds->blocker);
- error_free(bmds->blocker);
-
- /* Save ctx, because bmds->blk can disappear during blk_unref. */
- ctx = blk_get_aio_context(bmds->blk);
- aio_context_acquire(ctx);
- blk_unref(bmds->blk);
- aio_context_release(ctx);
-
- g_free(bmds->blk_name);
- g_free(bmds->aio_bitmap);
- g_free(bmds);
- }
-}
-
-/* Called with iothread lock taken. */
-static void block_migration_cleanup(void *opaque)
-{
- BlkMigBlock *blk;
-
- bdrv_drain_all();
-
- block_migration_cleanup_bmds();
-
- blk_mig_lock();
- 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 int block_save_setup(QEMUFile *f, void *opaque)
-{
- int ret;
-
- trace_migration_block_save("setup", block_mig_state.submitted,
- block_mig_state.transferred);
-
- qemu_mutex_lock_iothread();
- ret = init_blk_migration(f);
- if (ret < 0) {
- qemu_mutex_unlock_iothread();
- return ret;
- }
-
- /* start track dirty blocks */
- ret = set_dirty_tracking();
-
- qemu_mutex_unlock_iothread();
-
- if (ret) {
- return ret;
- }
-
- 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_bytes = qemu_file_total_transferred(f);
- int64_t delta_bytes;
-
- trace_migration_block_save("iterate", 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.read_done * BLK_MIG_BLOCK_SIZE <
- qemu_file_get_rate_limit(f) &&
- block_mig_state.submitted < MAX_PARALLEL_IO &&
- (block_mig_state.submitted + block_mig_state.read_done) <
- MAX_IO_BUFFERS) {
- 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);
- delta_bytes = qemu_file_total_transferred(f) - last_bytes;
- if (delta_bytes > 0) {
- return 1;
- } else if (delta_bytes < 0) {
- return -1;
- } else {
- return 0;
- }
-}
-
-/* Called with iothread lock taken. */
-
-static int block_save_complete(QEMUFile *f, void *opaque)
-{
- int ret;
-
- trace_migration_block_save("complete", 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);
-
- trace_migration_block_save_complete();
-
- qemu_put_be64(f, BLK_MIG_FLAG_EOS);
-
- /* Make sure that our BlockBackends are gone, so that the block driver
- * nodes can be inactivated. */
- block_migration_cleanup_bmds();
-
- return 0;
-}
-
-static void block_state_pending(void *opaque,
- uint64_t *res_precopy_only,
- uint64_t *res_compatible,
- uint64_t *res_postcopy_only)
-{
- /* Estimate pending number of bytes to send */
- uint64_t pending;
-
- qemu_mutex_lock_iothread();
- pending = get_remaining_dirty();
- qemu_mutex_unlock_iothread();
-
- blk_mig_lock();
- pending += block_mig_state.submitted * BLK_MIG_BLOCK_SIZE +
- block_mig_state.read_done * BLK_MIG_BLOCK_SIZE;
- blk_mig_unlock();
-
- /* Report at least one block pending during bulk phase */
- if (!pending && !block_mig_state.bulk_completed) {
- pending = BLK_MIG_BLOCK_SIZE;
- }
-
- trace_migration_block_state_pending(pending);
- /* We don't do postcopy */
- *res_precopy_only += 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;
- BlockBackend *blk, *blk_prev = NULL;
- Error *local_err = NULL;
- uint8_t *buf;
- int64_t total_sectors = 0;
- int nr_sectors;
- int ret;
- BlockDriverInfo bdi;
- int cluster_size = BLK_MIG_BLOCK_SIZE;
-
- do {
- addr = qemu_get_be64(f);
-
- flags = addr & (BDRV_SECTOR_SIZE - 1);
- 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';
-
- blk = blk_by_name(device_name);
- if (!blk) {
- fprintf(stderr, "Error unknown block device %s\n",
- device_name);
- return -EINVAL;
- }
-
- if (blk != blk_prev) {
- blk_prev = blk;
- total_sectors = blk_nb_sectors(blk);
- if (total_sectors <= 0) {
- error_report("Error getting length of block device %s",
- device_name);
- return -EINVAL;
- }
-
- blk_activate(blk, &local_err);
- if (local_err) {
- error_report_err(local_err);
- return -EINVAL;
- }
-
- ret = bdrv_get_info(blk_bs(blk), &bdi);
- if (ret == 0 && bdi.cluster_size > 0 &&
- bdi.cluster_size <= BLK_MIG_BLOCK_SIZE &&
- BLK_MIG_BLOCK_SIZE % bdi.cluster_size == 0) {
- cluster_size = bdi.cluster_size;
- } else {
- cluster_size = BLK_MIG_BLOCK_SIZE;
- }
- }
-
- 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 = blk_pwrite_zeroes(blk, addr * BDRV_SECTOR_SIZE,
- nr_sectors * BDRV_SECTOR_SIZE,
- BDRV_REQ_MAY_UNMAP);
- } else {
- int i;
- int64_t cur_addr;
- uint8_t *cur_buf;
-
- buf = g_malloc(BLK_MIG_BLOCK_SIZE);
- qemu_get_buffer(f, buf, BLK_MIG_BLOCK_SIZE);
- for (i = 0; i < BLK_MIG_BLOCK_SIZE / cluster_size; i++) {
- cur_addr = addr * BDRV_SECTOR_SIZE + i * cluster_size;
- cur_buf = buf + i * cluster_size;
-
- if ((!block_mig_state.zero_blocks ||
- cluster_size < BLK_MIG_BLOCK_SIZE) &&
- buffer_is_zero(cur_buf, cluster_size)) {
- ret = blk_pwrite_zeroes(blk, cur_addr,
- cluster_size,
- BDRV_REQ_MAY_UNMAP);
- } else {
- ret = blk_pwrite(blk, cur_addr, cluster_size, cur_buf,
- 0);
- }
- if (ret < 0) {
- break;
- }
- }
- 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: 0x%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 bool block_is_active(void *opaque)
-{
- return migrate_use_block();
-}
-
-static SaveVMHandlers savevm_block_handlers = {
- .save_setup = block_save_setup,
- .save_live_iterate = block_save_iterate,
- .save_live_complete_precopy = block_save_complete,
- .state_pending_exact = block_state_pending,
- .state_pending_estimate = block_state_pending,
- .load_state = block_load,
- .save_cleanup = block_migration_cleanup,
- .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("block", 0, 1, &savevm_block_handlers,
- &block_mig_state);
-}
projects / mirror_qemu.git / blobdiff