[dpdk-dev] [PATCH v2 06/10] net/virtio: fix queue setup consistency

[Olivier Matz <olivier.matz@6wind.com>]

In rx/tx queue setup functions, some code is executed only if
use_simple_rxtx == 1. The value of this variable can change depending on
the offload flags or sse support. If Rx queue setup is called before Tx
queue setup, it can result in an invalid configuration:

- dev_configure is called: use_simple_rxtx is initialized to 0
- rx queue setup is called: queues are initialized without simple path
  support
- tx queue setup is called: use_simple_rxtx switch to 1, and simple
  Rx/Tx handlers are selected

Fix this by postponing a part of Rx/Tx queue initialization in
dev_start(), as it was the case in the initial implementation.

Fixes: 48cec290a3d2 ("net/virtio: move queue configure code to proper place")
Cc: stable@dpdk.org

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
 drivers/net/virtio/virtio_ethdev.c | 13 +++++++++++++
 drivers/net/virtio/virtio_ethdev.h |  6 ++++++
 drivers/net/virtio/virtio_rxtx.c   | 40 ++++++++++++++++++++++++++++++--------
 3 files changed, 51 insertions(+), 8 deletions(-)

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 8eee3ff80..c7888f103 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -1737,6 +1737,19 @@ virtio_dev_start(struct rte_eth_dev *dev)
 	struct virtnet_rx *rxvq;
 	struct virtnet_tx *txvq __rte_unused;
 	struct virtio_hw *hw = dev->data->dev_private;
+	int 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);
+		if (ret < 0)
+			return ret;
+	}
+	for (i = 0; i < dev->data->nb_tx_queues; i++) {
+		ret = virtio_dev_tx_queue_setup_finish(dev, i);
+		if (ret < 0)
+			return ret;
+	}
 
 	/* check if lsc interrupt feature is enabled */
 	if (dev->data->dev_conf.intr_conf.lsc) {
diff --git a/drivers/net/virtio/virtio_ethdev.h b/drivers/net/virtio/virtio_ethdev.h
index c3413c6d9..2039bc547 100644
--- a/drivers/net/virtio/virtio_ethdev.h
+++ b/drivers/net/virtio/virtio_ethdev.h
@@ -92,10 +92,16 @@ int  virtio_dev_rx_queue_setup(struct rte_eth_dev *dev, uint16_t rx_queue_id,
 		const struct rte_eth_rxconf *rx_conf,
 		struct rte_mempool *mb_pool);
 
+int virtio_dev_rx_queue_setup_finish(struct rte_eth_dev *dev,
+				uint16_t rx_queue_id);
+
 int  virtio_dev_tx_queue_setup(struct rte_eth_dev *dev, uint16_t tx_queue_id,
 		uint16_t nb_tx_desc, unsigned int socket_id,
 		const struct rte_eth_txconf *tx_conf);
 
+int virtio_dev_tx_queue_setup_finish(struct rte_eth_dev *dev,
+				uint16_t tx_queue_id);
+
 uint16_t virtio_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 		uint16_t nb_pkts);
 
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index e30377c51..a32e3229f 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -421,9 +421,6 @@ virtio_dev_rx_queue_setup(struct rte_eth_dev *dev,
 	struct virtio_hw *hw = dev->data->dev_private;
 	struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 	struct virtnet_rx *rxvq;
-	int error, nbufs;
-	struct rte_mbuf *m;
-	uint16_t desc_idx;
 
 	PMD_INIT_FUNC_TRACE();
 
@@ -440,10 +437,24 @@ virtio_dev_rx_queue_setup(struct rte_eth_dev *dev,
 	}
 	dev->data->rx_queues[queue_idx] = rxvq;
 
+	return 0;
+}
+
+int
+virtio_dev_rx_queue_setup_finish(struct rte_eth_dev *dev, uint16_t queue_idx)
+{
+	uint16_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_RQ_QUEUE_IDX;
+	struct virtio_hw *hw = dev->data->dev_private;
+	struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
+	struct virtnet_rx *rxvq = &vq->rxq;
+	struct rte_mbuf *m;
+	uint16_t desc_idx;
+	int error, nbufs;
+
+	PMD_INIT_FUNC_TRACE();
 
 	/* Allocate blank mbufs for the each rx descriptor */
 	nbufs = 0;
-	error = ENOSPC;
 
 	if (hw->use_simple_rxtx) {
 		for (desc_idx = 0; desc_idx < vq->vq_nentries;
@@ -534,7 +545,6 @@ virtio_dev_tx_queue_setup(struct rte_eth_dev *dev,
 	struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
 	struct virtnet_tx *txvq;
 	uint16_t tx_free_thresh;
-	uint16_t desc_idx;
 
 	PMD_INIT_FUNC_TRACE();
 
@@ -563,9 +573,24 @@ virtio_dev_tx_queue_setup(struct rte_eth_dev *dev,
 
 	vq->vq_free_thresh = tx_free_thresh;
 
-	if (hw->use_simple_rxtx) {
-		uint16_t mid_idx  = vq->vq_nentries >> 1;
+	dev->data->tx_queues[queue_idx] = txvq;
+	return 0;
+}
+
+int
+virtio_dev_tx_queue_setup_finish(struct rte_eth_dev *dev,
+				uint16_t queue_idx)
+{
+	uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_TQ_QUEUE_IDX;
+	struct virtio_hw *hw = dev->data->dev_private;
+	struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
+	uint16_t mid_idx = vq->vq_nentries >> 1;
+	struct virtnet_tx *txvq = &vq->txq;
+	uint16_t desc_idx;
 
+	PMD_INIT_FUNC_TRACE();
+
+	if (hw->use_simple_rxtx) {
 		for (desc_idx = 0; desc_idx < mid_idx; desc_idx++) {
 			vq->vq_ring.avail->ring[desc_idx] =
 				desc_idx + mid_idx;
@@ -587,7 +612,6 @@ virtio_dev_tx_queue_setup(struct rte_eth_dev *dev,
 
 	VIRTQUEUE_DUMP(vq);
 
-	dev->data->tx_queues[queue_idx] = txvq;
 	return 0;
 }
 
-- 
2.11.0