[dpdk-dev] [PATCH 7/9] net/virtio: rationalize setting of Rx/Tx handlers

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

The selection of Rx/Tx handlers is done at several places,
group them in one function set_rxtx_funcs().

The update of hw->use_simple_rxtx is also rationalized:
- initialized to 1 (prefer simple path)
- in dev configure or rx/tx queue setup, if something prevents from
  using the simple path, change it to 0.
- in dev start, set the handlers according to hw->use_simple_rxtx.

Cc: stable@dpdk.org

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
 drivers/net/virtio/virtio_ethdev.c | 52 +++++++++++++++++++++++++++++---------
 drivers/net/virtio/virtio_rxtx.c   | 23 +++++------------
 2 files changed, 46 insertions(+), 29 deletions(-)

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index c7888f103..8dad3095f 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -1235,14 +1235,36 @@ virtio_interrupt_handler(void *param)
 
 }
 
+/* set rx and tx handlers according to what is supported */
 static void
-rx_func_get(struct rte_eth_dev *eth_dev)
+set_rxtx_funcs(struct rte_eth_dev *eth_dev)
 {
 	struct virtio_hw *hw = eth_dev->data->dev_private;
-	if (vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF))
+
+	if (hw->use_simple_rxtx) {
+		PMD_INIT_LOG(INFO, "virtio: using simple Rx path on port %u",
+			eth_dev->data->port_id);
+		eth_dev->rx_pkt_burst = virtio_recv_pkts_vec;
+	} else if (vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF)) {
+		PMD_INIT_LOG(INFO,
+			"virtio: using mergeable buffer Rx path on port %u",
+			eth_dev->data->port_id);
 		eth_dev->rx_pkt_burst = &virtio_recv_mergeable_pkts;
-	else
+	} else {
+		PMD_INIT_LOG(INFO, "virtio: using standard Rx path on port %u",
+			eth_dev->data->port_id);
 		eth_dev->rx_pkt_burst = &virtio_recv_pkts;
+	}
+
+	if (hw->use_simple_rxtx) {
+		PMD_INIT_LOG(INFO, "virtio: using simple Tx path on port %u",
+			eth_dev->data->port_id);
+		eth_dev->tx_pkt_burst = virtio_xmit_pkts_simple;
+	} else {
+		PMD_INIT_LOG(INFO, "virtio: using standard Tx path on port %u",
+			eth_dev->data->port_id);
+		eth_dev->tx_pkt_burst = virtio_xmit_pkts;
+	}
 }
 
 /* Only support 1:1 queue/interrupt mapping so far.
@@ -1367,8 +1389,6 @@ virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t req_features)
 	else
 		eth_dev->data->dev_flags &= ~RTE_ETH_DEV_INTR_LSC;
 
-	rx_func_get(eth_dev);
-
 	/* Setting up rx_header size for the device */
 	if (vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF) ||
 	    vtpci_with_feature(hw, VIRTIO_F_VERSION_1))
@@ -1534,7 +1554,6 @@ eth_virtio_dev_init(struct rte_eth_dev *eth_dev)
 	RTE_BUILD_BUG_ON(RTE_PKTMBUF_HEADROOM < sizeof(struct virtio_net_hdr_mrg_rxbuf));
 
 	eth_dev->dev_ops = &virtio_eth_dev_ops;
-	eth_dev->tx_pkt_burst = &virtio_xmit_pkts;
 
 	if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
 		if (!hw->virtio_user_dev) {
@@ -1544,12 +1563,8 @@ eth_virtio_dev_init(struct rte_eth_dev *eth_dev)
 		}
 
 		virtio_set_vtpci_ops(hw);
-		if (hw->use_simple_rxtx) {
-			eth_dev->tx_pkt_burst = virtio_xmit_pkts_simple;
-			eth_dev->rx_pkt_burst = virtio_recv_pkts_vec;
-		} else {
-			rx_func_get(eth_dev);
-		}
+		set_rxtx_funcs(eth_dev);
+
 		return 0;
 	}
 
@@ -1726,6 +1741,18 @@ virtio_dev_configure(struct rte_eth_dev *dev)
 			return -EBUSY;
 		}
 
+	hw->use_simple_rxtx = 1;
+
+#if defined RTE_ARCH_X86
+	if (!rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE3))
+		hw->use_simple_rxtx = 0;
+#elif defined RTE_ARCH_ARM64 || defined CONFIG_RTE_ARCH_ARM
+	if (!rte_cpu_get_flag_enabled(RTE_CPUFLAG_NEON))
+		hw->use_simple_rxtx = 0;
+#endif
+	if (vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF))
+		hw->use_simple_rxtx = 0;
+
 	return 0;
 }
 
@@ -1802,6 +1829,7 @@ virtio_dev_start(struct rte_eth_dev *dev)
 		VIRTQUEUE_DUMP(txvq->vq);
 	}
 
+	set_rxtx_funcs(dev);
 	hw->started = 1;
 
 	/* Initialize Link state */
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index a32e3229f..c9d97b643 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -505,25 +505,14 @@ static void
 virtio_update_rxtx_handler(struct rte_eth_dev *dev,
 			   const struct rte_eth_txconf *tx_conf)
 {
-	uint8_t use_simple_rxtx = 0;
 	struct virtio_hw *hw = dev->data->dev_private;
+	uint8_t use_simple_rxtx = hw->use_simple_rxtx;
 
-#if defined RTE_ARCH_X86
-	if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE3))
-		use_simple_rxtx = 1;
-#elif defined RTE_ARCH_ARM64 || defined CONFIG_RTE_ARCH_ARM
-	if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_NEON))
-		use_simple_rxtx = 1;
-#endif
-	/* Use simple rx/tx func if single segment and no offloads */
-	if (use_simple_rxtx &&
-	    (tx_conf->txq_flags & VIRTIO_SIMPLE_FLAGS) == VIRTIO_SIMPLE_FLAGS &&
-	    !vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF)) {
-		PMD_INIT_LOG(INFO, "Using simple rx/tx path");
-		dev->tx_pkt_burst = virtio_xmit_pkts_simple;
-		dev->rx_pkt_burst = virtio_recv_pkts_vec;
-		hw->use_simple_rxtx = use_simple_rxtx;
-	}
+	/* cannot use simple rxtx funcs with multisegs or offloads */
+	if ((tx_conf->txq_flags & VIRTIO_SIMPLE_FLAGS) != VIRTIO_SIMPLE_FLAGS)
+		use_simple_rxtx = 0;
+
+	hw->use_simple_rxtx = use_simple_rxtx;
 }
 
 /*
-- 
2.11.0