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Diffstat (limited to 'migration')
-rw-r--r--migration/block.c65
1 files changed, 52 insertions, 13 deletions
diff --git a/migration/block.c b/migration/block.c
index 3a8330a4b3..72883d7c64 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -54,17 +54,25 @@ typedef struct BlkMigDevState {
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;
- /* Protected by block migration lock. */
+ /* 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;
- Error *blocker;
} BlkMigDevState;
typedef struct BlkMigBlock {
@@ -100,7 +108,7 @@ typedef struct BlkMigState {
int prev_progress;
int bulk_completed;
- /* Lock must be taken _inside_ the iothread lock. */
+ /* Lock must be taken _inside_ the iothread lock and any AioContexts. */
QemuMutex lock;
} BlkMigState;
@@ -264,11 +272,13 @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
if (bmds->shared_base) {
qemu_mutex_lock_iothread();
+ aio_context_acquire(bdrv_get_aio_context(bs));
while (cur_sector < total_sectors &&
!bdrv_is_allocated(bs, cur_sector, MAX_IS_ALLOCATED_SEARCH,
&nr_sectors)) {
cur_sector += nr_sectors;
}
+ aio_context_release(bdrv_get_aio_context(bs));
qemu_mutex_unlock_iothread();
}
@@ -302,11 +312,21 @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
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(bdrv_get_aio_context(bmds->bs));
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);
+ aio_context_release(bdrv_get_aio_context(bmds->bs));
qemu_mutex_unlock_iothread();
bmds->cur_sector = cur_sector + nr_sectors;
@@ -321,8 +341,10 @@ static int set_dirty_tracking(void)
int ret;
QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+ aio_context_acquire(bdrv_get_aio_context(bmds->bs));
bmds->dirty_bitmap = bdrv_create_dirty_bitmap(bmds->bs, BLOCK_SIZE,
NULL, NULL);
+ aio_context_release(bdrv_get_aio_context(bmds->bs));
if (!bmds->dirty_bitmap) {
ret = -errno;
goto fail;
@@ -333,18 +355,24 @@ static int set_dirty_tracking(void)
fail:
QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
if (bmds->dirty_bitmap) {
+ aio_context_acquire(bdrv_get_aio_context(bmds->bs));
bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap);
+ aio_context_release(bdrv_get_aio_context(bmds->bs));
}
}
return ret;
}
+/* Called with iothread lock taken. */
+
static void unset_dirty_tracking(void)
{
BlkMigDevState *bmds;
QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+ aio_context_acquire(bdrv_get_aio_context(bmds->bs));
bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap);
+ aio_context_release(bdrv_get_aio_context(bmds->bs));
}
}
@@ -444,7 +472,7 @@ static void blk_mig_reset_dirty_cursor(void)
}
}
-/* Called with iothread lock taken. */
+/* Called with iothread lock and AioContext taken. */
static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds,
int is_async)
@@ -527,7 +555,9 @@ static int blk_mig_save_dirty_block(QEMUFile *f, int is_async)
int ret = 1;
QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+ aio_context_acquire(bdrv_get_aio_context(bmds->bs));
ret = mig_save_device_dirty(f, bmds, is_async);
+ aio_context_release(bdrv_get_aio_context(bmds->bs));
if (ret <= 0) {
break;
}
@@ -585,7 +615,9 @@ static int64_t get_remaining_dirty(void)
int64_t dirty = 0;
QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+ aio_context_acquire(bdrv_get_aio_context(bmds->bs));
dirty += bdrv_get_dirty_count(bmds->dirty_bitmap);
+ aio_context_release(bdrv_get_aio_context(bmds->bs));
}
return dirty << BDRV_SECTOR_BITS;
@@ -597,21 +629,28 @@ static void block_migration_cleanup(void *opaque)
{
BlkMigDevState *bmds;
BlkMigBlock *blk;
+ AioContext *ctx;
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);
+
+ /* Save ctx, because bmds->bs can disappear during bdrv_unref. */
+ ctx = bdrv_get_aio_context(bmds->bs);
+ aio_context_acquire(ctx);
bdrv_unref(bmds->bs);
+ aio_context_release(ctx);
+
g_free(bmds->aio_bitmap);
g_free(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);
@@ -633,13 +672,12 @@ static int block_save_setup(QEMUFile *f, void *opaque)
/* start track dirty blocks */
ret = set_dirty_tracking();
+ qemu_mutex_unlock_iothread();
+
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);
@@ -761,17 +799,18 @@ static void block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size,
uint64_t pending;
qemu_mutex_lock_iothread();
+ pending = get_remaining_dirty();
+ qemu_mutex_unlock_iothread();
+
blk_mig_lock();
- pending = get_remaining_dirty() +
- block_mig_state.submitted * BLOCK_SIZE +
- block_mig_state.read_done * BLOCK_SIZE;
+ pending += block_mig_state.submitted * BLOCK_SIZE +
+ block_mig_state.read_done * BLOCK_SIZE;
+ blk_mig_unlock();
/* 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);
/* We don't do postcopy */
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-22 12:20:26 +0000