--- /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-common.h"
+#include "block/block.h"
+#include "qemu/error-report.h"
+#include "qemu/main-loop.h"
+#include "hw/hw.h"
+#include "qemu/queue.h"
+#include "qemu/timer.h"
+#include "migration/block.h"
+#include "migration/migration.h"
+#include "sysemu/blockdev.h"
+#include "sysemu/block-backend.h"
+#include <assert.h>
+
+#define BLOCK_SIZE (1 << 20)
+#define BDRV_SECTORS_PER_DIRTY_CHUNK (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
+
+//#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 BlkMigDevState {
+ /* Written during setup phase. Can be read without a lock. */
+ BlockDriverState *bs;
+ int shared_base;
+ int64_t total_sectors;
+ QSIMPLEQ_ENTRY(BlkMigDevState) entry;
+
+ /* Only used by migration thread. Does not need a lock. */
+ int bulk_completed;
+ int64_t cur_sector;
+ int64_t cur_dirty;
+
+ /* Protected by block migration lock. */
+ unsigned long *aio_bitmap;
+ int64_t completed_sectors;
+ BdrvDirtyBitmap *dirty_bitmap;
+ Error *blocker;
+} BlkMigDevState;
+
+typedef struct BlkMigBlock {
+ /* Only used by migration thread. */
+ uint8_t *buf;
+ BlkMigDevState *bmds;
+ int64_t sector;
+ int nr_sectors;
+ struct iovec iov;
+ QEMUIOVector qiov;
+ BlockAIOCB *aiocb;
+
+ /* Protected by block migration lock. */
+ int ret;
+ QSIMPLEQ_ENTRY(BlkMigBlock) entry;
+} BlkMigBlock;
+
+typedef struct BlkMigState {
+ /* Written during setup phase. Can be read without a lock. */
+ int blk_enable;
+ int shared_base;
+ QSIMPLEQ_HEAD(bmds_list, BlkMigDevState) bmds_list;
+ int64_t total_sector_sum;
+ bool zero_blocks;
+
+ /* Protected by lock. */
+ QSIMPLEQ_HEAD(blk_list, 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. */
+ 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, 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(bdrv_get_device_name(blk->bmds->bs));
+ qemu_put_byte(f, len);
+ qemu_put_buffer(f, (uint8_t *)bdrv_get_device_name(blk->bmds->bs), 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, BLOCK_SIZE);
+}
+
+int blk_mig_active(void)
+{
+ return !QSIMPLEQ_EMPTY(&block_mig_state.bmds_list);
+}
+
+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 < bdrv_nb_sectors(bmds->bs)) {
+ 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)
+{
+ BlockDriverState *bs = bmds->bs;
+ int64_t bitmap_size;
+
+ bitmap_size = bdrv_nb_sectors(bs) + 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;
+ BlockDriverState *bs = bmds->bs;
+ BlkMigBlock *blk;
+ int nr_sectors;
+
+ if (bmds->shared_base) {
+ qemu_mutex_lock_iothread();
+ while (cur_sector < total_sectors &&
+ !bdrv_is_allocated(bs, cur_sector, MAX_IS_ALLOCATED_SEARCH,
+ &nr_sectors)) {
+ cur_sector += nr_sectors;
+ }
+ 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(BLOCK_SIZE);
+ blk->bmds = bmds;
+ blk->sector = cur_sector;
+ blk->nr_sectors = nr_sectors;
+
+ 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_mig_lock();
+ block_mig_state.submitted++;
+ blk_mig_unlock();
+
+ qemu_mutex_lock_iothread();
+ blk->aiocb = bdrv_aio_readv(bs, cur_sector, &blk->qiov,
+ nr_sectors, blk_mig_read_cb, blk);
+
+ bdrv_reset_dirty_bitmap(bmds->dirty_bitmap, cur_sector, nr_sectors);
+ 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(bmds->bs, 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->bs, bmds->dirty_bitmap);
+ }
+ }
+ return ret;
+}
+
+static void unset_dirty_tracking(void)
+{
+ BlkMigDevState *bmds;
+
+ QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+ bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap);
+ }
+}
+
+static void init_blk_migration(QEMUFile *f)
+{
+ BlockDriverState *bs;
+ BlkMigDevState *bmds;
+ int64_t sectors;
+
+ 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_next(NULL); bs; bs = bdrv_next(bs)) {
+ if (bdrv_is_read_only(bs)) {
+ continue;
+ }
+
+ sectors = bdrv_nb_sectors(bs);
+ if (sectors <= 0) {
+ return;
+ }
+
+ bmds = g_new0(BlkMigDevState, 1);
+ bmds->bs = bs;
+ bmds->bulk_completed = 0;
+ bmds->total_sectors = sectors;
+ bmds->completed_sectors = 0;
+ bmds->shared_base = block_mig_state.shared_base;
+ alloc_aio_bitmap(bmds);
+ error_setg(&bmds->blocker, "block device is in use by migration");
+ bdrv_op_block_all(bs, bmds->blocker);
+ bdrv_ref(bs);
+
+ block_mig_state.total_sector_sum += sectors;
+
+ if (bmds->shared_base) {
+ DPRINTF("Start migration for %s with shared base image\n",
+ bdrv_get_device_name(bs));
+ } else {
+ DPRINTF("Start full migration for %s\n", bdrv_get_device_name(bs));
+ }
+
+ QSIMPLEQ_INSERT_TAIL(&block_mig_state.bmds_list, bmds, entry);
+ }
+}
+
+/* Called with no lock taken. */
+
+static int blk_mig_save_bulked_block(QEMUFile *f)
+{
+ int64_t completed_sector_sum = 0;
+ BlkMigDevState *bmds;
+ int progress;
+ int ret = 0;
+
+ QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+ if (bmds->bulk_completed == 0) {
+ if (mig_save_device_bulk(f, bmds) == 1) {
+ /* completed bulk section for this device */
+ bmds->bulk_completed = 1;
+ }
+ completed_sector_sum += bmds->completed_sectors;
+ ret = 1;
+ break;
+ } else {
+ completed_sector_sum += bmds->completed_sectors;
+ }
+ }
+
+ if (block_mig_state.total_sector_sum != 0) {
+ progress = completed_sector_sum * 100 /
+ block_mig_state.total_sector_sum;
+ } else {
+ progress = 100;
+ }
+ if (progress != block_mig_state.prev_progress) {
+ block_mig_state.prev_progress = progress;
+ qemu_put_be64(f, (progress << BDRV_SECTOR_BITS)
+ | BLK_MIG_FLAG_PROGRESS);
+ DPRINTF("Completed %d %%\r", progress);
+ }
+
+ return ret;
+}
+
+static void blk_mig_reset_dirty_cursor(void)
+{
+ BlkMigDevState *bmds;
+
+ QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+ bmds->cur_dirty = 0;
+ }
+}
+
+/* Called with iothread lock taken. */
+
+static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds,
+ int is_async)
+{
+ BlkMigBlock *blk;
+ int64_t total_sectors = bmds->total_sectors;
+ int64_t sector;
+ int nr_sectors;
+ int ret = -EIO;
+
+ for (sector = bmds->cur_dirty; sector < bmds->total_sectors;) {
+ blk_mig_lock();
+ if (bmds_aio_inflight(bmds, sector)) {
+ blk_mig_unlock();
+ bdrv_drain(bmds->bs);
+ } 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_new(BlkMigBlock, 1);
+ 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_bitmap(bmds->dirty_bitmap, 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->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);
+ int64_t delta_ftell;
+
+ 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);
+ delta_ftell = qemu_ftell(f) - last_ftell;
+ if (delta_ftell > 0) {
+ return 1;
+ } else if (delta_ftell < 0) {
+ return -1;
+ } else {
+ return 0;
+ }
+}
+
+/* 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 <= max_size && !block_mig_state.bulk_completed) {
+ pending = max_size + 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;
+ BlockBackend *blk;
+ 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';
+
+ blk = blk_by_name(device_name);
+ if (!blk) {
+ fprintf(stderr, "Error unknown block device %s\n",
+ device_name);
+ return -EINVAL;
+ }
+ bs = blk_bs(blk);
+
+ 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);
+}
Code Review / kvmfornfv.git / blobdiff