[dpdk-dev] [PATCH 2/4] net/vhost: improve Tx path selection

[Maxime Coquelin]

This patch improves the Tx path selection depending on
whether the application request for offloads, and on whether
offload features have been negotiated.

When the application doesn't request for Tx offload features,
the corresponding features bits aren't negotiated.

When Tx offload virtio features have been negotiated, ensure
the simple Tx path isn't selected.

Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
 drivers/net/virtio/virtio_ethdev.c | 20 ++++++++++++++++++--
 drivers/net/virtio/virtio_ethdev.h |  3 ---
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index e68e9d067..5730620ed 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -1798,8 +1798,10 @@ static int
 virtio_dev_configure(struct rte_eth_dev *dev)
 {
 	const struct rte_eth_rxmode *rxmode = &dev->data->dev_conf.rxmode;
+	const struct rte_eth_txmode *txmode = &dev->data->dev_conf.txmode;
 	struct virtio_hw *hw = dev->data->dev_private;
 	uint64_t rx_offloads = rxmode->offloads;
+	uint64_t tx_offloads = txmode->offloads;
 	uint64_t req_features;
 	int ret;
 
@@ -1821,6 +1823,15 @@ virtio_dev_configure(struct rte_eth_dev *dev)
 			(1ULL << VIRTIO_NET_F_GUEST_TSO4) |
 			(1ULL << VIRTIO_NET_F_GUEST_TSO6);
 
+	if (tx_offloads & (DEV_TX_OFFLOAD_TCP_CKSUM |
+				DEV_TX_OFFLOAD_UDP_CKSUM))
+		req_features |= (1ULL << VIRTIO_NET_F_CSUM);
+
+	if (tx_offloads & DEV_TX_OFFLOAD_TCP_TSO)
+		req_features |=
+			(1ULL << VIRTIO_NET_F_HOST_TSO4) |
+			(1ULL << VIRTIO_NET_F_HOST_TSO6);
+
 	/* if request features changed, reinit the device */
 	if (req_features != hw->req_guest_features) {
 		ret = virtio_init_device(dev, req_features);
@@ -1885,6 +1896,11 @@ virtio_dev_configure(struct rte_eth_dev *dev)
 			   DEV_RX_OFFLOAD_TCP_CKSUM))
 		hw->use_simple_rx = 0;
 
+	if (tx_offloads & (DEV_TX_OFFLOAD_TCP_CKSUM |
+				DEV_TX_OFFLOAD_UDP_CKSUM |
+				DEV_TX_OFFLOAD_TCP_TSO))
+		hw->use_simple_tx = 0;
+
 	return 0;
 }
 
@@ -2138,14 +2154,14 @@ virtio_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
 
 	dev_info->tx_offload_capa = DEV_TX_OFFLOAD_MULTI_SEGS |
 				    DEV_TX_OFFLOAD_VLAN_INSERT;
-	if (hw->guest_features & (1ULL << VIRTIO_NET_F_CSUM)) {
+	if (host_features & (1ULL << VIRTIO_NET_F_CSUM)) {
 		dev_info->tx_offload_capa |=
 			DEV_TX_OFFLOAD_UDP_CKSUM |
 			DEV_TX_OFFLOAD_TCP_CKSUM;
 	}
 	tso_mask = (1ULL << VIRTIO_NET_F_HOST_TSO4) |
 		(1ULL << VIRTIO_NET_F_HOST_TSO6);
-	if ((hw->guest_features & tso_mask) == tso_mask)
+	if ((host_features & tso_mask) == tso_mask)
 		dev_info->tx_offload_capa |= DEV_TX_OFFLOAD_TCP_TSO;
 }
 
diff --git a/drivers/net/virtio/virtio_ethdev.h b/drivers/net/virtio/virtio_ethdev.h
index bb40064ea..b603665c7 100644
--- a/drivers/net/virtio/virtio_ethdev.h
+++ b/drivers/net/virtio/virtio_ethdev.h
@@ -28,9 +28,6 @@
 	 1u << VIRTIO_NET_F_CTRL_VQ	  |	\
 	 1u << VIRTIO_NET_F_CTRL_RX	  |	\
 	 1u << VIRTIO_NET_F_CTRL_VLAN	  |	\
-	 1u << VIRTIO_NET_F_CSUM	  |	\
-	 1u << VIRTIO_NET_F_HOST_TSO4	  |	\
-	 1u << VIRTIO_NET_F_HOST_TSO6	  |	\
 	 1u << VIRTIO_NET_F_MRG_RXBUF	  |	\
 	 1u << VIRTIO_NET_F_MTU	| \
 	 1ULL << VIRTIO_NET_F_GUEST_ANNOUNCE |	\
-- 
2.14.3