diff --git a/block/block-backend.c b/block/block-backend.c
index 2c62210687..3199f84e96 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1205,7 +1205,7 @@ static void coroutine_fn blk_wait_while_drained(BlockBackend *blk)
 
 /* To be called between exactly one pair of blk_inc/dec_in_flight() */
 static int coroutine_fn
-blk_do_preadv(BlockBackend *blk, int64_t offset, unsigned int bytes,
+blk_do_preadv(BlockBackend *blk, int64_t offset, int64_t bytes,
               QEMUIOVector *qiov, BdrvRequestFlags flags)
 {
     int ret;
@@ -1236,7 +1236,7 @@ blk_do_preadv(BlockBackend *blk, int64_t offset, unsigned int bytes,
 }
 
 int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
-                               unsigned int bytes, QEMUIOVector *qiov,
+                               int64_t bytes, QEMUIOVector *qiov,
                                BdrvRequestFlags flags)
 {
     int ret;
diff --git a/block/trace-events b/block/trace-events
index f2d0a9b62a..ff397ffff4 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -5,7 +5,7 @@ bdrv_open_common(void *bs, const char *filename, int flags, const char *format_n
 bdrv_lock_medium(void *bs, bool locked) "bs %p locked %d"
 
 # block-backend.c
-blk_co_preadv(void *blk, void *bs, int64_t offset, unsigned int bytes, int flags) "blk %p bs %p offset %"PRId64" bytes %u flags 0x%x"
+blk_co_preadv(void *blk, void *bs, int64_t offset, int64_t bytes, int flags) "blk %p bs %p offset %"PRId64" bytes %" PRId64 " flags 0x%x"
 blk_co_pwritev(void *blk, void *bs, int64_t offset, unsigned int bytes, int flags) "blk %p bs %p offset %"PRId64" bytes %u flags 0x%x"
 blk_root_attach(void *child, void *blk, void *bs) "child %p blk %p bs %p"
 blk_root_detach(void *child, void *blk, void *bs) "child %p blk %p bs %p"
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 82bae55161..442fd705bb 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -126,7 +126,7 @@ BlockBackend *blk_by_dev(void *dev);
 BlockBackend *blk_by_qdev_id(const char *id, Error **errp);
 void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque);
 int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
-                               unsigned int bytes, QEMUIOVector *qiov,
+                               int64_t bytes, QEMUIOVector *qiov,
                                BdrvRequestFlags flags);
 int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset,
                                      unsigned int bytes,