vhost: copy_from_user -> __copy_from_user

copy_from_user is pretty high on perf top profile,
replacing it with __copy_from_user helps.
It's also safe because we do access_ok checks during setup.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index b0cc7f8ca4de..2ab291241635 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1171,7 +1171,7 @@ int vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq,
                                i, vq->num, head);
                         return -EINVAL;
                 }
-                ret = copy_from_user(&desc, vq->desc + i, sizeof desc);
+                ret = __copy_from_user(&desc, vq->desc + i, sizeof desc);
                 if (unlikely(ret)) {
                         vq_err(vq, "Failed to get descriptor: idx %d addr %p\n",
                                i, vq->desc + i);