Re: [dpdk-dev] [PATCH] net/vhost: fix vhost invalid state

[Jens Freimann <jfreimann@redhat.com>]

On Tue, Apr 10, 2018 at 10:18:09AM -0400, Junjie Chen wrote:
>dev_start sets *dev_attached* after setup queues, this sets device to
>invalid state since no frontend is attached. Also destroy_device set
>*started* to zero which makes *allow_queuing* always zero until dev_start
>get called again. Actually, we should not determine queues existence by
>*dev_attached* but by queues pointers or other separated variable(s).
>
>Fixes: 30a701a53737 ("net/vhost: fix crash when creating vdev
>dynamically")
>
>Signed-off-by: Junjie Chen <junjie.j.chen@intel.com>

So this fixes the problem I saw with allow_queueing always being zero
and the error message "VHOST_CONFIG: (0) device not found". 

However with this patch on top of virtio-next/master no packets are
being forwarded to the guest and back anymore.

When I use virtio-next/master and revert 30a701a53737 both works fine. 

regards,
Jens 

>---
> drivers/net/vhost/rte_eth_vhost.c | 64 +++++++++++++++++++++++----------------
> 1 file changed, 38 insertions(+), 26 deletions(-)
>
>diff --git a/drivers/net/vhost/rte_eth_vhost.c b/drivers/net/vhost/rte_eth_vhost.c
>index 11b6076..6a2ff76 100644
>--- a/drivers/net/vhost/rte_eth_vhost.c
>+++ b/drivers/net/vhost/rte_eth_vhost.c
>@@ -118,6 +118,7 @@ struct pmd_internal {
> 	char *iface_name;
> 	uint16_t max_queues;
> 	uint16_t vid;
>+	uint16_t queue_ready;
> 	rte_atomic32_t started;
> };
>
>@@ -528,10 +529,13 @@ update_queuing_status(struct rte_eth_dev *dev)
> 	unsigned int i;
> 	int allow_queuing = 1;
>
>-	if (rte_atomic32_read(&internal->dev_attached) == 0)
>+	if (!dev->data->rx_queues || !dev->data->tx_queues) {
>+		RTE_LOG(ERR, PMD, "RX/TX queues not setup yet\n");
> 		return;
>+	}
>
>-	if (rte_atomic32_read(&internal->started) == 0)
>+	if (rte_atomic32_read(&internal->started) == 0 ||
>+	    rte_atomic32_read(&internal->dev_attached) == 0)
> 		allow_queuing = 0;
>
> 	/* Wait until rx/tx_pkt_burst stops accessing vhost device */
>@@ -576,6 +580,8 @@ queue_setup(struct rte_eth_dev *eth_dev, struct pmd_internal *internal)
> 		vq->internal = internal;
> 		vq->port = eth_dev->data->port_id;
> 	}
>+
>+	internal->queue_ready = 1;
> }
>
> static int
>@@ -607,13 +613,10 @@ new_device(int vid)
> #endif
>
> 	internal->vid = vid;
>-	if (eth_dev->data->rx_queues && eth_dev->data->tx_queues) {
>+	if (eth_dev->data->rx_queues && eth_dev->data->tx_queues)
> 		queue_setup(eth_dev, internal);
>-		rte_atomic32_set(&internal->dev_attached, 1);
>-	} else {
>-		RTE_LOG(INFO, PMD, "RX/TX queues have not setup yet\n");
>-		rte_atomic32_set(&internal->dev_attached, 0);
>-	}
>+	else
>+		RTE_LOG(INFO, PMD, "RX/TX queues not setup yet\n");
>
> 	for (i = 0; i < rte_vhost_get_vring_num(vid); i++)
> 		rte_vhost_enable_guest_notification(vid, i, 0);
>@@ -622,6 +625,7 @@ new_device(int vid)
>
> 	eth_dev->data->dev_link.link_status = ETH_LINK_UP;
>
>+	rte_atomic32_set(&internal->dev_attached, 1);
> 	update_queuing_status(eth_dev);
>
> 	RTE_LOG(INFO, PMD, "Vhost device %d created\n", vid);
>@@ -657,17 +661,19 @@ destroy_device(int vid)
>
> 	eth_dev->data->dev_link.link_status = ETH_LINK_DOWN;
>
>-	for (i = 0; i < eth_dev->data->nb_rx_queues; i++) {
>-		vq = eth_dev->data->rx_queues[i];
>-		if (vq == NULL)
>-			continue;
>-		vq->vid = -1;
>-	}
>-	for (i = 0; i < eth_dev->data->nb_tx_queues; i++) {
>-		vq = eth_dev->data->tx_queues[i];
>-		if (vq == NULL)
>-			continue;
>-		vq->vid = -1;
>+	if (eth_dev->data->rx_queues && eth_dev->data->tx_queues) {
>+		for (i = 0; i < eth_dev->data->nb_rx_queues; i++) {
>+			vq = eth_dev->data->rx_queues[i];
>+			if (!vq)
>+				continue;
>+			vq->vid = -1;
>+		}
>+		for (i = 0; i < eth_dev->data->nb_tx_queues; i++) {
>+			vq = eth_dev->data->tx_queues[i];
>+			if (!vq)
>+				continue;
>+			vq->vid = -1;
>+		}
> 	}
>
> 	state = vring_states[eth_dev->data->port_id];
>@@ -792,11 +798,14 @@ eth_dev_start(struct rte_eth_dev *eth_dev)
> {
> 	struct pmd_internal *internal = eth_dev->data->dev_private;
>
>-	if (unlikely(rte_atomic32_read(&internal->dev_attached) == 0)) {
>-		queue_setup(eth_dev, internal);
>-		rte_atomic32_set(&internal->dev_attached, 1);
>+	if (!eth_dev->data->rx_queues || !eth_dev->data->tx_queues) {
>+		RTE_LOG(ERR, PMD, "RX/TX queues not exist yet\n");
>+		return -1;
> 	}
>
>+	if (!internal->queue_ready)
>+		queue_setup(eth_dev, internal);
>+
> 	rte_atomic32_set(&internal->started, 1);
> 	update_queuing_status(eth_dev);
>
>@@ -836,10 +845,13 @@ eth_dev_close(struct rte_eth_dev *dev)
> 	pthread_mutex_unlock(&internal_list_lock);
> 	rte_free(list);
>
>-	for (i = 0; i < dev->data->nb_rx_queues; i++)
>-		rte_free(dev->data->rx_queues[i]);
>-	for (i = 0; i < dev->data->nb_tx_queues; i++)
>-		rte_free(dev->data->tx_queues[i]);
>+	if (dev->data->rx_queues)
>+		for (i = 0; i < dev->data->nb_rx_queues; i++)
>+			rte_free(dev->data->rx_queues[i]);
>+
>+	if (dev->data->tx_queues)
>+		for (i = 0; i < dev->data->nb_tx_queues; i++)
>+			rte_free(dev->data->tx_queues[i]);
>
> 	rte_free(dev->data->mac_addrs);
> 	free(internal->dev_name);
>-- 
>2.0.1
>