Re: [dpdk-dev] [PATCH] net/virtio: fix crash when device reconnecting

[Ye Xiaolong <xiaolong.ye@intel.com>]

Hi, Marvin

On 04/14, Marvin Liu wrote:
>When doing virtio device initialization, virtqueues will be reset in
>server mode if ring type is packed. This will cause issue because queues
>have been freed in the beginning of device initialization.
>
>Fix this issue by splitting device initial process and device reinit
>process. Virt queues won't be freed or realloc in reinit process. Also
>moved virtio device initialization from configuration to start stage,
>which can reduce number of reinitialization times.
>
>Fixes: 6ebbf4109f35 ("net/virtio-user: fix packed ring server mode")

I think it also needs to cc stable.

>
>Signed-off-by: Marvin Liu <yong.liu@intel.com>
>
>diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
>index 21570e5cf..8c84bfe91 100644
>--- a/drivers/net/virtio/virtio_ethdev.c
>+++ b/drivers/net/virtio/virtio_ethdev.c
>@@ -1670,7 +1670,9 @@ virtio_configure_intr(struct rte_eth_dev *dev)
> 
> /* reset device and renegotiate features if needed */
> static int
>-virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t req_features)
>+virtio_init_device(struct rte_eth_dev *eth_dev,
>+		   uint64_t req_features,
>+		   bool reinit)
> {
> 	struct virtio_hw *hw = eth_dev->data->dev_private;
> 	struct virtio_net_config *config;
>@@ -1681,7 +1683,7 @@ virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t req_features)
> 	/* Reset the device although not necessary at startup */
> 	vtpci_reset(hw);
> 
>-	if (hw->vqs) {
>+	if (hw->vqs && !reinit) {
> 		virtio_dev_free_mbufs(eth_dev);
> 		virtio_free_queues(hw);
> 	}
>@@ -1794,9 +1796,11 @@ virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t req_features)
> 			VLAN_TAG_LEN - hw->vtnet_hdr_size;
> 	}
> 
>-	ret = virtio_alloc_queues(eth_dev);
>-	if (ret < 0)
>-		return ret;
>+	if (!reinit) {
>+		ret = virtio_alloc_queues(eth_dev);
>+		if (ret < 0)
>+			return ret;
>+	}
> 
> 	if (eth_dev->data->dev_conf.intr_conf.rxq) {
> 		if (virtio_configure_intr(eth_dev) < 0) {
>@@ -1925,7 +1929,8 @@ eth_virtio_dev_init(struct rte_eth_dev *eth_dev)
> 	rte_spinlock_init(&hw->state_lock);
> 
> 	/* reset device and negotiate default features */
>-	ret = virtio_init_device(eth_dev, VIRTIO_PMD_DEFAULT_GUEST_FEATURES);
>+	ret = virtio_init_device(eth_dev, VIRTIO_PMD_DEFAULT_GUEST_FEATURES,
>+			false);
> 	if (ret < 0)
> 		goto err_virtio_init;
> 
>@@ -2091,12 +2096,6 @@ virtio_dev_configure(struct rte_eth_dev *dev)
> 		return -EINVAL;
> 	}
> 
>-	if (dev->data->dev_conf.intr_conf.rxq) {
>-		ret = virtio_init_device(dev, hw->req_guest_features);
>-		if (ret < 0)
>-			return ret;
>-	}
>-
> 	if (rxmode->max_rx_pkt_len > hw->max_mtu + ether_hdr_len)
> 		req_features &= ~(1ULL << VIRTIO_NET_F_MTU);
> 
>@@ -2120,7 +2119,7 @@ virtio_dev_configure(struct rte_eth_dev *dev)
> 
> 	/* if request features changed, reinit the device */
> 	if (req_features != hw->req_guest_features) {
>-		ret = virtio_init_device(dev, req_features);
>+		ret = virtio_negotiate_features(hw, req_features);

Why do we need to change virtio_init_device to virtio_negotiate_features here? 

Thanks,
Xiaolong

> 		if (ret < 0)
> 			return ret;
> 	}
>@@ -2235,6 +2234,11 @@ virtio_dev_start(struct rte_eth_dev *dev)
> 	struct virtio_hw *hw = dev->data->dev_private;
> 	int ret;
> 
>+	/* reinit the device */
>+	ret = virtio_init_device(dev, hw->req_guest_features, true);
>+	if (ret < 0)
>+		return ret;
>+
> 	/* Finish the initialization of the queues */
> 	for (i = 0; i < dev->data->nb_rx_queues; i++) {
> 		ret = virtio_dev_rx_queue_setup_finish(dev, i);
>-- 
>2.17.1
>