On 8/20/21 2:47 PM, Andrew Rybchenko wrote:
> From: Ivan Ilchenko <ivan.ilche...@oktetlabs.ru>
>
> Descriptors number may be set less than queue size for split queue
> vectorized Rx path. Pointers to mbufs for received packets are
> obtained from SW ring, that is initially filled with them in the end
> of queue setup in virtio_dev_rx_queue_setup_finish(). The begin of the
> SW ring filled up to the size of descriptors number. At queue size
> offset from the begin of the SW ring pointers to some fake mbuf are also
> set for wrapping purpose. So the ring may contains the hole of invalid
> pointers from descriptors number offset to queue size offset, and split
> vectorized Rx routines could write to the invalid addresses since they
> use the ring up to the queue size. Fix this by setting descriptors
> number to queue size on Rx queue setup.
>
> Fixes: fc3d66212fed ("virtio: add vector Rx")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Ivan Ilchenko <ivan.ilche...@oktetlabs.ru>
> Signed-off-by: Andrew Rybchenko <andrew.rybche...@oktetlabs.ru>
> ---
> drivers/net/virtio/virtio_rxtx.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/virtio/virtio_rxtx.c
> b/drivers/net/virtio/virtio_rxtx.c
> index 18f03c9fc9..97ed69596a 100644
> --- a/drivers/net/virtio/virtio_rxtx.c
> +++ b/drivers/net/virtio/virtio_rxtx.c
> @@ -706,8 +706,14 @@ virtio_dev_rx_queue_setup(struct rte_eth_dev *dev,
> }
> vq->vq_free_thresh = rx_free_thresh;
>
> - if (nb_desc > vq->vq_nentries)
> + /*
> + * For split ring vectorized path descriptors number must be
> + * equal to the ring size.
> + */
> + if (nb_desc > vq->vq_nentries ||
> + (!virtio_with_packed_queue(hw) && hw->use_vec_rx)) {
> nb_desc = vq->vq_nentries;
> + }
> vq->vq_free_cnt = RTE_MIN(vq->vq_free_cnt, nb_desc);
>
> rxvq = &vq->rxq;
>
Reviewed-by: Maxime Coquelin <maxime.coque...@redhat.com>
Thanks,
Maxime
