Re: [PATCH RFC v8 02/11] vhost: use batched get_vq_desc version

On Wed, Jun 17, 2020 at 11:19:26AM +0800, Jason Wang wrote:

On 2020/6/11 下午7:34, Michael S. Tsirkin wrote:

quoted

  static void vhost_vq_free_iovecs(struct vhost_virtqueue *vq)
  {
  	kfree(vq->descs);

@@ -394,6 +400,9 @@ static long vhost_dev_alloc_iovecs(struct vhost_dev *dev)
  	for (i = 0; i < dev->nvqs; ++i) {
  		vq = dev->vqs[i];
  		vq->max_descs = dev->iov_limit;
+		if (vhost_vq_num_batch_descs(vq) < 0) {
+			return -EINVAL;
+		}

This check breaks vdpa which set iov_limit to zero. Consider iov_limit is
meaningless to vDPA, I wonder we can skip the test when device doesn't use
worker.

Thanks

It doesn't need iovecs at all, right?

-- 
MST