DPDK patches and discussions
 help / color / mirror / Atom feed
From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>,
	Chenbo Xia <chenbo.xia@intel.com>,
	Jianfeng Tan <jianfeng.tan@intel.com>,
	Huawei Xie <huawei.xie@intel.com>
Cc: dev@dpdk.org, Ivan Ilchenko <ivan.ilchenko@oktetlabs.ru>,
	stable@dpdk.org
Subject: Re: [dpdk-dev] [PATCH] net/virtio: turn SW RxQ size to that of split vec. virtqueue
Date: Mon, 13 Sep 2021 21:46:22 +0200	[thread overview]
Message-ID: <878c9de0-3842-7cff-98f1-be83b7abca1c@redhat.com> (raw)
In-Reply-To: <20210820124752.3522683-1-andrew.rybchenko@oktetlabs.ru>



On 8/20/21 2:47 PM, Andrew Rybchenko wrote:
> From: Ivan Ilchenko <ivan.ilchenko@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: stable@dpdk.org
> 
> Signed-off-by: Ivan Ilchenko <ivan.ilchenko@oktetlabs.ru>
> Signed-off-by: Andrew Rybchenko <andrew.rybchenko@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.coquelin@redhat.com>

Thanks,
Maxime


  reply	other threads:[~2021-09-13 19:46 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-20 12:47 Andrew Rybchenko
2021-09-13 19:46 ` Maxime Coquelin [this message]
2021-09-14 11:26 ` Maxime Coquelin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=878c9de0-3842-7cff-98f1-be83b7abca1c@redhat.com \
    --to=maxime.coquelin@redhat.com \
    --cc=andrew.rybchenko@oktetlabs.ru \
    --cc=chenbo.xia@intel.com \
    --cc=dev@dpdk.org \
    --cc=huawei.xie@intel.com \
    --cc=ivan.ilchenko@oktetlabs.ru \
    --cc=jianfeng.tan@intel.com \
    --cc=stable@dpdk.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).