Thanks for the feedback Long.
I've made both changes you suggested, plus one additional one to not try and
allocate an mbuf if the pool is null.
This means if a packet is received on a Rx queue that isn't being polled we
will see it appear as "mbuf allocation failed" rather than causing a segfault.
Cheers,
Alan
> -----Original Message-----
> From: Long Li <lon...@microsoft.com>
> Sent: Tuesday, March 12, 2024 7:09 PM
> To: Alan Elder <alan.el...@microsoft.com>; Ferruh Yigit
> <ferruh.yi...@amd.com>; Andrew Rybchenko
> <andrew.rybche...@oktetlabs.ru>
> Cc: dev@dpdk.org; stephen <step...@networkplumber.org>
> Subject: RE: [PATCH v2] net/netvsc: fix number Tx queues > Rx queues
>
> > a/drivers/net/netvsc/hn_rxtx.c b/drivers/net/netvsc/hn_rxtx.c index
> > 9bf1ec5509..c0aaeaa972 100644
> > --- a/drivers/net/netvsc/hn_rxtx.c
> > +++ b/drivers/net/netvsc/hn_rxtx.c
> > @@ -243,6 +243,7 @@ hn_dev_tx_queue_setup(struct rte_eth_dev *dev, {
> > struct hn_data *hv = dev->data->dev_private;
> > struct hn_tx_queue *txq;
> > + struct hn_rx_queue *rxq;
> > char name[RTE_MEMPOOL_NAMESIZE];
> > uint32_t tx_free_thresh;
> > int err = -ENOMEM;
> > @@ -301,6 +302,22 @@ hn_dev_tx_queue_setup(struct rte_eth_dev *dev,
> > goto error;
> > }
> >
> > + /*
> > + * If there are more Tx queues than Rx queues, allocate rx_queues
> > + * with event buffer so that Tx completion messages can still be
> > + * received
> > + */
> > + if (queue_idx >= dev->data->nb_rx_queues) {
> > + rxq = hn_rx_queue_alloc(hv, queue_idx, socket_id);
>
> Need to check if rxq is NULL.
>
> > + /*
> > + * Don't allocate mbuf pool or rx ring. RSS is always
> > configured
> > + * to ensure packets aren't received by this Rx queue.
> > + */
> > + rxq->mb_pool = NULL;
> > + rxq->rx_ring = NULL;
> > + dev->data->rx_queues[queue_idx] = rxq;
> > + }
> > +
> > txq->agg_szmax = RTE_MIN(hv->chim_szmax, hv->rndis_agg_size);
> > txq->agg_pktmax = hv->rndis_agg_pkts;
> > txq->agg_align = hv->rndis_agg_align; @@ -354,6 +371,17 @@ static
> > void hn_txd_put(struct hn_tx_queue *txq, struct hn_txdesc *txd)
> > rte_mempool_put(txq->txdesc_pool, txd); }
> >
> > +static void
> > +hn_rx_queue_free_common(struct hn_rx_queue *rxq) {
> > + if (!rxq)
> > + return;
> > +
> > + rte_free(rxq->rxbuf_info);
> > + rte_free(rxq->event_buf);
> > + rte_free(rxq);
> > +}
> > +
> > void
> > hn_dev_tx_queue_release(struct rte_eth_dev *dev, uint16_t qid) { @@
> > -364,6
> > +392,13 @@ hn_dev_tx_queue_release(struct rte_eth_dev *dev, uint16_t
> > +qid)
> > if (!txq)
> > return;
> >
> > + /*
> > + * Free any Rx queues allocated for a Tx queue without a
> corresponding
> > + * Rx queue
> > + */
> > + if (qid >= dev->data->nb_rx_queues)
> > + hn_rx_queue_free_common(dev->data->rx_queues[qid]);
> > +
> > rte_mempool_free(txq->txdesc_pool);
> >
> > rte_memzone_free(txq->tx_rndis_mz);
> > @@ -942,6 +977,13 @@ hn_dev_rx_queue_setup(struct rte_eth_dev *dev,
> > if (queue_idx == 0) {
> > rxq = hv->primary;
> > } else {
> > + /*
> > + * If the number of Tx queues was previously greater than
> > + * the number of Rx queues, we may already have allocated
> > + * an rxq. If so, free it now before allocating a new one.
> > + */
> > + hn_rx_queue_free_common(dev->data-
> > >rx_queues[queue_idx]);
>
> This logic seems strange. How about check if rxq is already allocated. If not,
> allocate it.
>
> Something like:
>
> if (!dev->data->rx_queues[queue_idx])
> rxq = hn_rx_queue_alloc(hv, queue_idx, socket_id);
>
>
>
> Thanks,
>
> Long
