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

[Jens Freimann <jfreimann@redhat.com>]

On Thu, Apr 05, 2018 at 10:40:29PM +0800, Tiwei Bie wrote:
>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.

Hmm, you are right. Seems like this code never ran. I'll be more
careful testing even last minute changes now. 

regards,
Jens 
>
>> > +		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>
>>