On Tue, Jun 23, 2020 at 10:25 AM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
>
> On Tue, Jun 23, 2020 at 09:00:57AM +0200, Eugenio Perez Martin wrote:
> > On Tue, Jun 23, 2020 at 4:51 AM Jason Wang <jasowang@xxxxxxxxxx> wrote:
> > >
> > >
> > > On 2020/6/23 上午12:00, Michael S. Tsirkin wrote:
> > > > 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:
> > > >>> 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
> > >
> >
> > I think that the kmalloc_array returns ZERO_SIZE_PTR for all of them
> > in that case, so I didn't bother to skip the kmalloc_array parts.
> > Would you prefer to skip them all and let them NULL? Or have I
> > misunderstood what you mean?
> >
> > Thanks!
>
> Sorry about being unclear. I just meant that it seems cleaner
> to check for iov_limit being 0 not for worker thread.
Actually yes, I also think that iov_limit == 0 is a better check.
Changing for the next revision if everyone agrees.
Thanks!
>
> --
> MST
>
