diff options
| author | Peter Lieven <pl@kamp.de> | 2015-02-02 14:52:22 +0100 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2015-02-06 17:24:21 +0100 |
| commit | c99495ac1b4a27cb57bf04ed1a169177aeea2649 (patch) | |
| tree | 652bb0df118f435fd27a9c4e7df65bd04d9bd3d1 | |
| parent | 95f7142abc86a916682bd735aecd90172ffa0d30 (diff) | |
| download | qemu-c99495ac1b4a27cb57bf04ed1a169177aeea2649.zip | |
virtio-blk: add a knob to disable request merging
this adds a knob to disable request merging for debugging or benchmarks if dedired.
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
| -rw-r--r-- | hw/block/virtio-blk.c | 5 | ||||
| -rw-r--r-- | include/hw/virtio/virtio-blk.h | 1 |
2 files changed, 5 insertions, 1 deletions
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index d0a01a8864..8c51a295d9 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -531,7 +531,8 @@ void virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb) /* merge would exceed maximum number of requests or IO direction * changes */ if (mrb->num_reqs > 0 && (mrb->num_reqs == VIRTIO_BLK_MAX_MERGE_REQS || - is_write != mrb->is_write)) { + is_write != mrb->is_write || + !req->dev->conf.request_merging)) { virtio_blk_submit_multireq(req->dev->blk, mrb); } @@ -950,6 +951,8 @@ static Property virtio_blk_properties[] = { #ifdef __linux__ DEFINE_PROP_BIT("scsi", VirtIOBlock, conf.scsi, 0, true), #endif + DEFINE_PROP_BIT("request-merging", VirtIOBlock, conf.request_merging, 0, + true), DEFINE_PROP_BIT("x-data-plane", VirtIOBlock, conf.data_plane, 0, false), DEFINE_PROP_END_OF_LIST(), }; diff --git a/include/hw/virtio/virtio-blk.h b/include/hw/virtio/virtio-blk.h index 2027a64093..fc7d311a43 100644 --- a/include/hw/virtio/virtio-blk.h +++ b/include/hw/virtio/virtio-blk.h @@ -113,6 +113,7 @@ struct VirtIOBlkConf uint32_t scsi; uint32_t config_wce; uint32_t data_plane; + uint32_t request_merging; }; struct VirtIOBlockDataPlane; |