Re: [dpdk-dev] [PATCH v3 04/21] net/virtio: add packed virtqueue helpers

[Tiwei Bie <tiwei.bie@intel.com>]

On Thu, Apr 05, 2018 at 04:27:51PM +0200, Maxime Coquelin wrote:
> On 04/05/2018 12:10 PM, Jens Freimann wrote:
> > Add helper functions to set/clear and check descriptor flags.
> > 
> > Signed-off-by: Jens Freimann <jfreimann@redhat.com>
> > ---
> >   drivers/net/virtio/virtio_ring.h | 33 +++++++++++++++++++++++++++++++++
> >   drivers/net/virtio/virtqueue.c   | 10 ++++++++++
> >   2 files changed, 43 insertions(+)
[...]
> > diff --git a/drivers/net/virtio/virtqueue.c b/drivers/net/virtio/virtqueue.c
> > index a7d0a9cbe..4f95ed5c8 100644
> > --- a/drivers/net/virtio/virtqueue.c
> > +++ b/drivers/net/virtio/virtqueue.c
> > @@ -58,6 +58,7 @@ virtqueue_detach_unused(struct virtqueue *vq)
> >   void
> >   virtqueue_rxvq_flush(struct virtqueue *vq)
> >   {
> > +	struct vring_desc_packed *descs = vq->vq_ring.desc_packed;
> >   	struct virtnet_rx *rxq = &vq->rxq;
> >   	struct virtio_hw *hw = vq->hw;
> >   	struct vring_used_elem *uep;
> > @@ -65,6 +66,15 @@ virtqueue_rxvq_flush(struct virtqueue *vq)
> >   	uint16_t used_idx, desc_idx;
> >   	uint16_t nb_used, i;
> > +	if (vtpci_packed_queue(vq->hw)) {
> > +		i = vq->vq_used_cons_idx & (vq->vq_nentries - 1);
> > +		while (desc_is_used(&descs[i])) {
> > +			rte_pktmbuf_free(vq->sw_ring[i]);
> > +			vq->vq_free_cnt++;
> > +		}

You need to increase i here. Otherwise you are looping
on the same entry. To increase i, you also need to keep
track of the number of descriptors need to be skipped
for each used descriptor.

> > +		return;
> > +	}
> > +
> >   	nb_used = VIRTQUEUE_NUSED(vq);
> >   	for (i = 0; i < nb_used; i++) {
> > 
> 
> With style comments taken into account:
> 
> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>