vhost: Remove custom vhost rcu usage

Now, vq->private_data is always accessed under vq mutex. No need to play
the vhost rcu trick.

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 2 insertions, 8 deletions

diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 42298cd23c73..4465ed5f316d 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -103,14 +103,8 @@ struct vhost_virtqueue {
         struct iovec iov[UIO_MAXIOV];
         struct iovec *indirect;
         struct vring_used_elem *heads;
-        /* We use a kind of RCU to access private pointer.
-         * All readers access it from worker, which makes it possible to
-         * flush the vhost_work instead of synchronize_rcu. Therefore readers do
-         * not need to call rcu_read_lock/rcu_read_unlock: the beginning of
-         * vhost_work execution acts instead of rcu_read_lock() and the end of
-         * vhost_work execution acts instead of rcu_read_unlock().
-         * Writers use virtqueue mutex. */
-        void __rcu *private_data;
+        /* Protected by virtqueue mutex. */
+        void *private_data;
         /* Log write descriptors */
         void __user *log_base;
         struct vhost_log *log;