diff options
| -rw-r--r-- | block-migration.c | 54 | ||||
| -rw-r--r-- | include/qemu/atomic.h | 1 |
2 files changed, 52 insertions, 3 deletions
diff --git a/block-migration.c b/block-migration.c index d62a8b80ba..b726c6c002 100644 --- a/block-migration.c +++ b/block-migration.c @@ -54,7 +54,7 @@ typedef struct BlkMigDevState { int64_t cur_sector; int64_t cur_dirty; - /* Protected by iothread lock. */ + /* Protected by block migration lock. */ unsigned long *aio_bitmap; int64_t completed_sectors; } BlkMigDevState; @@ -69,7 +69,7 @@ typedef struct BlkMigBlock { QEMUIOVector qiov; BlockDriverAIOCB *aiocb; - /* Protected by iothread lock. */ + /* Protected by block migration lock. */ int ret; QSIMPLEQ_ENTRY(BlkMigBlock) entry; } BlkMigBlock; @@ -81,7 +81,7 @@ typedef struct BlkMigState { QSIMPLEQ_HEAD(bmds_list, BlkMigDevState) bmds_list; int64_t total_sector_sum; - /* Protected by iothread lock. */ + /* Protected by lock. */ QSIMPLEQ_HEAD(blk_list, BlkMigBlock) blk_list; int submitted; int read_done; @@ -90,10 +90,23 @@ typedef struct BlkMigState { 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); +} + static void blk_send(QEMUFile *f, BlkMigBlock * blk) { int len; @@ -120,9 +133,11 @@ 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; } @@ -142,6 +157,9 @@ uint64_t blk_mig_bytes_total(void) 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; @@ -154,6 +172,8 @@ static int bmds_aio_inflight(BlkMigDevState *bmds, int64_t sector) } } +/* Called with migration lock held. */ + static void bmds_set_aio_inflight(BlkMigDevState *bmds, int64_t sector_num, int nb_sectors, int set) { @@ -188,10 +208,13 @@ static void alloc_aio_bitmap(BlkMigDevState *bmds) 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); @@ -200,6 +223,7 @@ static void blk_mig_read_cb(void *opaque, int ret) block_mig_state.submitted--; block_mig_state.read_done++; assert(block_mig_state.submitted >= 0); + blk_mig_unlock(); } static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds) @@ -244,7 +268,9 @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds) 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(); blk->aiocb = bdrv_aio_readv(bs, cur_sector, &blk->qiov, nr_sectors, blk_mig_read_cb, blk); @@ -366,8 +392,12 @@ static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds, 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, sector)) { @@ -389,8 +419,11 @@ static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds, 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) { @@ -446,6 +479,7 @@ static int flush_blks(QEMUFile *f) __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; @@ -456,7 +490,9 @@ static int flush_blks(QEMUFile *f) } 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); @@ -465,6 +501,7 @@ static int flush_blks(QEMUFile *f) 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, @@ -493,6 +530,7 @@ static void blk_mig_cleanup(void) set_dirty_tracking(0); + blk_mig_lock(); while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != NULL) { QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry); bdrv_set_in_use(bmds->bs, 0); @@ -506,6 +544,7 @@ static void blk_mig_cleanup(void) g_free(blk->buf); g_free(blk); } + blk_mig_unlock(); } static void block_migration_cancel(void *opaque) @@ -548,9 +587,11 @@ static int block_save_iterate(QEMUFile *f, void *opaque) 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) { @@ -564,11 +605,13 @@ static int block_save_iterate(QEMUFile *f, void *opaque) 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) { @@ -595,7 +638,9 @@ static int block_save_complete(QEMUFile *f, void *opaque) /* 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); @@ -620,6 +665,7 @@ static uint64_t block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size) /* Estimate pending number of bytes to send */ uint64_t pending; + blk_mig_lock(); pending = get_remaining_dirty() + block_mig_state.submitted * BLOCK_SIZE + block_mig_state.read_done * BLOCK_SIZE; @@ -628,6 +674,7 @@ static uint64_t block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size) if (pending == 0 && !block_mig_state.bulk_completed) { pending = BLOCK_SIZE; } + blk_mig_unlock(); DPRINTF("Enter save live pending %" PRIu64 "\n", pending); return pending; @@ -739,6 +786,7 @@ 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); diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h index 96a194bbee..10becb6101 100644 --- a/include/qemu/atomic.h +++ b/include/qemu/atomic.h @@ -16,6 +16,7 @@ */ #define smp_wmb() barrier() #define smp_rmb() barrier() + /* * We use GCC builtin if it's available, as that can use * mfence on 32 bit as well, e.g. if built with -march=pentium-m. |