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

[Marvin Liu <yong.liu@intel.com>]

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")

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);
 		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