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>

parent d47effe1

drivers/vhost/vhost.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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);