Hi Maxime,
> -----Original Message-----
> From: Maxime Coquelin <maxime.coque...@redhat.com>
> Sent: Thursday, July 23, 2020 9:09 PM
> To: dev@dpdk.org; ma...@mellanox.com; Xia, Chenbo
> <chenbo....@intel.com>; Liu, Yong <yong....@intel.com>; Wang, Yinan
> <yinan.w...@intel.com>
> Cc: tho...@monjalon.net; Yigit, Ferruh <ferruh.yi...@intel.com>;
> david.march...@redhat.com; Maxime Coquelin
> <maxime.coque...@redhat.com>
> Subject: [PATCH 2/2] net/vhost: fix queue update
>
> Now that the vhost library saves the guest notifications enablement value in
> its
> virtqueues metadata, it is not necessary to do it in the vring_state_changed
> callback.
>
> One effect of the patch is also to prevent possible deadlock happening in
> vhost
> library.
>
> Fixes: 604052ae5395 ("net/vhost: support queue update")
>
> Reported-by: Yinan Wang <yinan.w...@intel.com>
> Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
> ---
> drivers/net/vhost/rte_eth_vhost.c | 25 ++++++-------------------
> 1 file changed, 6 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/net/vhost/rte_eth_vhost.c
> b/drivers/net/vhost/rte_eth_vhost.c
> index bbf79b2c0e..14b7b59f67 100644
> --- a/drivers/net/vhost/rte_eth_vhost.c
> +++ b/drivers/net/vhost/rte_eth_vhost.c
> @@ -94,7 +94,6 @@ struct vhost_queue {
> struct rte_mempool *mb_pool;
> uint16_t port;
> uint16_t virtqueue_id;
> - bool intr_en;
> struct vhost_stats stats;
> };
>
> @@ -547,8 +546,6 @@ eth_rxq_intr_enable(struct rte_eth_dev *dev, uint16_t
> qid)
> rte_vhost_enable_guest_notification(vq->vid, (qid << 1) + 1, 1);
> rte_wmb();
>
> - vq->intr_en = true;
> -
> return ret;
> }
>
> @@ -574,8 +571,6 @@ eth_rxq_intr_disable(struct rte_eth_dev *dev, uint16_t
> qid)
> rte_vhost_enable_guest_notification(vq->vid, (qid << 1) + 1, 0);
> rte_wmb();
>
> - vq->intr_en = false;
> -
> return 0;
> }
>
> @@ -841,7 +836,6 @@ vring_conf_update(int vid, struct rte_eth_dev *eth_dev,
> uint16_t vring_id)
> struct rte_eth_conf *dev_conf = ð_dev->data->dev_conf;
> struct pmd_internal *internal = eth_dev->data->dev_private;
> struct rte_vhost_vring vring;
> - struct vhost_queue *vq;
> int rx_idx = vring_id % 2 ? (vring_id - 1) >> 1 : -1;
> int ret = 0;
>
> @@ -853,21 +847,14 @@ vring_conf_update(int vid, struct rte_eth_dev
> *eth_dev, uint16_t vring_id)
> rte_atomic32_read(&internal->dev_attached) &&
> rte_atomic32_read(&internal->started) &&
> dev_conf->intr_conf.rxq) {
> - vq = eth_dev->data->rx_queues[rx_idx];
> ret = rte_vhost_get_vhost_vring(vid, vring_id, &vring);
> - if (!ret) {
> - if (vring.kickfd !=
> - eth_dev->intr_handle->efds[rx_idx]) {
> - VHOST_LOG(INFO,
> - "kickfd for rxq-%d was changed.\n",
> - rx_idx);
> - eth_dev->intr_handle->efds[rx_idx] =
> - vring.kickfd;
> - }
> + if (ret)
> + return ret;
Do you think it'll be better to add a VHOST_LOG here to show the get_vring
failure
like it's done in other place? But since it's the only place that will fail,
it's also easy
for user to find out. 😊
Thanks,
Chenbo
>
> - rte_vhost_enable_guest_notification(vid, vring_id,
> - vq->intr_en);
> - rte_wmb();
> + if (vring.kickfd != eth_dev->intr_handle->efds[rx_idx]) {
> + VHOST_LOG(INFO, "kickfd for rxq-%d was changed.\n",
> + rx_idx);
> + eth_dev->intr_handle->efds[rx_idx] = vring.kickfd;
> }
> }
>
> --
> 2.26.2
