diff options
| -rw-r--r-- | hw/block/virtio-blk.c | 28 |
1 files changed, 10 insertions, 18 deletions
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index b88b726be1..f72d4b6069 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -407,24 +407,16 @@ void virtio_blk_submit_multireq(BlockBackend *blk, MultiReqBuffer *mrb) for (i = 0; i < mrb->num_reqs; i++) { VirtIOBlockReq *req = mrb->reqs[i]; if (num_reqs > 0) { - bool merge = true; - - /* merge would exceed maximum number of IOVs */ - if (niov + req->qiov.niov > IOV_MAX) { - merge = false; - } - - /* merge would exceed maximum transfer length of backend device */ - if (req->qiov.size / BDRV_SECTOR_SIZE + nb_sectors > max_xfer_len) { - merge = false; - } - - /* requests are not sequential */ - if (sector_num + nb_sectors != req->sector_num) { - merge = false; - } - - if (!merge) { + /* + * NOTE: We cannot merge the requests in below situations: + * 1. requests are not sequential + * 2. merge would exceed maximum number of IOVs + * 3. merge would exceed maximum transfer length of backend device + */ + if (sector_num + nb_sectors != req->sector_num || + niov > IOV_MAX - req->qiov.niov || + req->qiov.size / BDRV_SECTOR_SIZE > max_xfer_len || + nb_sectors > max_xfer_len - req->qiov.size / BDRV_SECTOR_SIZE) { submit_requests(blk, mrb, start, num_reqs, niov); num_reqs = 0; } |