diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2015-08-21 15:53:55 -0700 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2015-09-08 13:29:14 +0300 |
| commit | 53eab6fd2777dc7cb338519827e23f8bf892903e (patch) | |
| tree | 29fc9d97ab032f82cd49bad8737cd4c6d0ad223c /drivers/block | |
| parent | 64291f7db5bd8150a74ad2036f1037e6a0428df2 (diff) | |
virtio-blk: use VIRTIO_BLK_F_WCE and VIRTIO_BLK_F_CONFIG_WCE in virtio1
VIRTIO_BLK_F_CONFIG_WCE is important in order to achieve good performance
(up to 2x, though more realistically +30-40%) in latency-bound workloads.
However, it was removed by mistake together with VIRTIO_BLK_F_FLUSH.
It will be restored in the next revision of the virtio 1.0 standard, so
do the same in Linux.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/virtio_blk.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index d4d05f064d39..ea2c17c66dfb 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -478,8 +478,7 @@ static int virtblk_get_cache_mode(struct virtio_device *vdev) struct virtio_blk_config, wce, &writeback); if (err) - writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_WCE) || - virtio_has_feature(vdev, VIRTIO_F_VERSION_1); + writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_WCE); return writeback; } @@ -840,7 +839,7 @@ static unsigned int features_legacy[] = { static unsigned int features[] = { VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, - VIRTIO_BLK_F_TOPOLOGY, + VIRTIO_BLK_F_WCE, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, VIRTIO_BLK_F_MQ, }; |