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

[Jason Wang]

On 2020/6/23 äå12:00, Michael S. Tsirkin wrote:
> On Wed, Jun 17, 2020 at 11:19:26AM +0800, Jason Wang wrote:
> > On 2020/6/11 äå7:34, Michael S. Tsirkin wrote:
> > >    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


Yes, so we may choose to bypass the iovecs as well.

Thanks