Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull vhost infrastructure updates from Michael S. Tsirkin:
 "This reworks vhost core dropping unnecessary RCU uses in favor of VQ
  mutexes which are used on fast path anyway.  This fixes worst-case
  latency for users which change the memory mappings a lot.  Memory
  allocation for vhost-net now supports fallback on vmalloc (same as for
  vhost-scsi) this makes it possible to create the device on systems
  where memory is very fragmented, with slightly lower performance"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost: move memory pointer to VQs
  vhost: move acked_features to VQs
  vhost: replace rcu with mutex
  vhost-net: extend device allocation to vmalloc

1 files changed, 15 insertions, 11 deletions

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index aeb5131..e9c280f 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -606,7 +606,7 @@ tcm_vhost_do_evt_work(struct vhost_scsi *vs, struct tcm_vhost_evt *evt)
 
 again:
 	vhost_disable_notify(&vs->dev, vq);
-	head = vhost_get_vq_desc(&vs->dev, vq, vq->iov,
+	head = vhost_get_vq_desc(vq, vq->iov,
 			ARRAY_SIZE(vq->iov), &out, &in,
 			NULL, NULL);
 	if (head < 0) {
@@ -945,7 +945,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 	vhost_disable_notify(&vs->dev, vq);
 
 	for (;;) {
-		head = vhost_get_vq_desc(&vs->dev, vq, vq->iov,
+		head = vhost_get_vq_desc(vq, vq->iov,
 					ARRAY_SIZE(vq->iov), &out, &in,
 					NULL, NULL);
 		pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
@@ -1373,6 +1373,9 @@ err_dev:
 
 static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
 {
+	struct vhost_virtqueue *vq;
+	int i;
+
 	if (features & ~VHOST_SCSI_FEATURES)
 		return -EOPNOTSUPP;
 
@@ -1382,9 +1385,13 @@ static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
 		mutex_unlock(&vs->dev.mutex);
 		return -EFAULT;
 	}
-	vs->dev.acked_features = features;
-	smp_wmb();
-	vhost_scsi_flush(vs);
+
+	for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
+		vq = &vs->vqs[i].vq;
+		mutex_lock(&vq->mutex);
+		vq->acked_features = features;
+		mutex_unlock(&vq->mutex);
+	}
 	mutex_unlock(&vs->dev.mutex);
 	return 0;
 }
@@ -1591,10 +1598,6 @@ tcm_vhost_do_plug(struct tcm_vhost_tpg *tpg,
 		return;
 
 	mutex_lock(&vs->dev.mutex);
-	if (!vhost_has_feature(&vs->dev, VIRTIO_SCSI_F_HOTPLUG)) {
-		mutex_unlock(&vs->dev.mutex);
-		return;
-	}
 
 	if (plug)
 		reason = VIRTIO_SCSI_EVT_RESET_RESCAN;
@@ -1603,8 +1606,9 @@ tcm_vhost_do_plug(struct tcm_vhost_tpg *tpg,
 
 	vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 	mutex_lock(&vq->mutex);
-	tcm_vhost_send_evt(vs, tpg, lun,
-			VIRTIO_SCSI_T_TRANSPORT_RESET, reason);
+	if (vhost_has_feature(vq, VIRTIO_SCSI_F_HOTPLUG))
+		tcm_vhost_send_evt(vs, tpg, lun,
+				   VIRTIO_SCSI_T_TRANSPORT_RESET, reason);
 	mutex_unlock(&vq->mutex);
 	mutex_unlock(&vs->dev.mutex);
 }