[dpdk-dev] [PATCH 05/16] mlx4: add L2 tunnel (VXLAN) RX checksum offload support

[Adrien Mazarguil]

Depending on adapters features and VXLAN support in the kernel, VXLAN frames
can be automatically recognized, in which case checksum validation occurs on
inner and outer L3 and L4.

Signed-off-by: Adrien Mazarguil <adrien.mazarguil at 6wind.com>
Acked-by: Guillaume Gaudonville <guillaume.gaudonville at 6wind.com>
---
 drivers/net/mlx4/mlx4.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c
index cec894f..3210120 100644
--- a/drivers/net/mlx4/mlx4.c
+++ b/drivers/net/mlx4/mlx4.c
@@ -212,6 +212,7 @@ struct rxq {
 	} elts;
 	unsigned int sp:1; /* Use scattered RX elements. */
 	unsigned int csum:1; /* Enable checksum offloading. */
+	unsigned int csum_l2tun:1; /* Same for L2 tunnels. */
 	uint32_t mb_len; /* Length of a mp-issued mbuf. */
 	struct mlx4_rxq_stats stats; /* RX queue counters. */
 	unsigned int socket; /* CPU socket ID for allocations. */
@@ -285,6 +286,7 @@ struct priv {
 	unsigned int hw_tss:1; /* TSS is supported. */
 	unsigned int hw_rss:1; /* RSS is supported. */
 	unsigned int hw_csum:1; /* Checksum offload is supported. */
+	unsigned int hw_csum_l2tun:1; /* Same for L2 tunnels. */
 	unsigned int rss:1; /* RSS is enabled. */
 	unsigned int vf:1; /* This is a VF device. */
 #ifdef INLINE_RECV
@@ -2329,6 +2331,25 @@ rxq_wc_to_ol_flags(const struct rxq *rxq, uint64_t exp_wc_flags)
 				  IBV_EXP_L3_RX_CSUM_OK, PKT_RX_IP_CKSUM_BAD) |
 			TRANSPOSE(~exp_wc_flags,
 				  IBV_EXP_L4_RX_CSUM_OK, PKT_RX_L4_CKSUM_BAD);
+	/*
+	 * PKT_RX_IP_CKSUM_BAD and PKT_RX_L4_CKSUM_BAD are used in place
+	 * of PKT_RX_EIP_CKSUM_BAD because the latter is not functional
+	 * (its value is 0).
+	 */
+	if ((exp_wc_flags & IBV_EXP_L2_TUNNEL_PACKET) && (rxq->csum_l2tun))
+		ol_flags |=
+			TRANSPOSE(exp_wc_flags,
+				  IBV_EXP_L2_TUNNEL_IPV4_PACKET,
+				  PKT_RX_TUNNEL_IPV4_HDR) |
+			TRANSPOSE(exp_wc_flags,
+				  IBV_EXP_L2_TUNNEL_IPV6_PACKET,
+				  PKT_RX_TUNNEL_IPV6_HDR) |
+			TRANSPOSE(~exp_wc_flags,
+				  IBV_EXP_L2_TUNNEL_L3_RX_CSUM_OK,
+				  PKT_RX_IP_CKSUM_BAD) |
+			TRANSPOSE(~exp_wc_flags,
+				  IBV_EXP_L2_TUNNEL_L4_RX_CSUM_OK,
+				  PKT_RX_L4_CKSUM_BAD);
 	return ol_flags;
 }
 
@@ -2859,6 +2880,10 @@ rxq_rehash(struct rte_eth_dev *dev, struct rxq *rxq)
 		tmpl.csum = !!dev->data->dev_conf.rxmode.hw_ip_checksum;
 		rxq->csum = tmpl.csum;
 	}
+	if (priv->hw_csum_l2tun) {
+		tmpl.csum_l2tun = !!dev->data->dev_conf.rxmode.hw_ip_checksum;
+		rxq->csum_l2tun = tmpl.csum_l2tun;
+	}
 	/* Enable scattered packets support for this queue if necessary. */
 	if ((dev->data->dev_conf.rxmode.jumbo_frame) &&
 	    (dev->data->dev_conf.rxmode.max_rx_pkt_len >
@@ -3078,6 +3103,8 @@ rxq_setup(struct rte_eth_dev *dev, struct rxq *rxq, uint16_t desc,
 	/* Toggle RX checksum offload if hardware supports it. */
 	if (priv->hw_csum)
 		tmpl.csum = !!dev->data->dev_conf.rxmode.hw_ip_checksum;
+	if (priv->hw_csum_l2tun)
+		tmpl.csum_l2tun = !!dev->data->dev_conf.rxmode.hw_ip_checksum;
 	/* Enable scattered packets support for this queue if necessary. */
 	if ((dev->data->dev_conf.rxmode.jumbo_frame) &&
 	    (dev->data->dev_conf.rxmode.max_rx_pkt_len >
@@ -4270,6 +4297,8 @@ static const struct eth_dev_ops mlx4_dev_ops = {
 	.mac_addr_remove = mlx4_mac_addr_remove,
 	.mac_addr_add = mlx4_mac_addr_add,
 	.mtu_set = mlx4_dev_set_mtu,
+	.udp_tunnel_add = NULL,
+	.udp_tunnel_del = NULL,
 	.fdir_add_signature_filter = NULL,
 	.fdir_update_signature_filter = NULL,
 	.fdir_remove_signature_filter = NULL,
@@ -4599,6 +4628,11 @@ mlx4_pci_devinit(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev)
 		DEBUG("checksum offloading is %ssupported",
 		      (priv->hw_csum ? "" : "not "));
 
+		priv->hw_csum_l2tun = !!(exp_device_attr.exp_device_cap_flags &
+					 IBV_EXP_DEVICE_L2_TUNNEL_OFFLOADS);
+		DEBUG("L2 tunnel checksum offloads are %ssupported",
+		      (priv->hw_csum_l2tun ? "" : "not "));
+
 #ifdef INLINE_RECV
 		priv->inl_recv_size = mlx4_getenv_int("MLX4_INLINE_RECV_SIZE");
 
-- 
2.1.0