- dbs->acb = dbs->io_func(dbs->bs, dbs->sector_num, &dbs->iov,
- dbs->iov.size / 512, dma_bdrv_cb, dbs);
+ if (dbs->iov.size & ~BDRV_SECTOR_MASK) {
+ qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & ~BDRV_SECTOR_MASK);
+ }
+
+ dbs->acb = dbs->io_func(dbs->blk, dbs->sector_num, &dbs->iov,
+ dbs->iov.size / 512, dma_blk_cb, dbs);