diff mbox

[1/2] ixgbe: Add support for UDP-encapsulated tx checksum offload

Message ID 20150610174426.85125.33055.stgit@mdrustad-wks.jf.intel.com
State Superseded
Headers show

Commit Message

Rustad, Mark D June 10, 2015, 5:44 p.m. UTC 
By using GSO for UDP-encapsulated packets, all ixgbe devices can
be directed to generate checksums for the inner headers because
the outer UDP checksum can be zero. So point the machinery at the
inner headers and have the hardware generate the checksum.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c |   60 ++++++++++++++++++++-----
 1 file changed, 48 insertions(+), 12 deletions(-)

Comments

Jesse Gross June 10, 2015, 6:58 p.m. UTC | #1 
On Wed, Jun 10, 2015 at 10:44 AM, Mark D Rustad <mark.d.rustad@intel.com> wrote:
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> index 03336013a76c..3c9bc7cc7d10 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> +static netdev_features_t
> +ixgbe_features_check(struct sk_buff *skb, struct net_device *dev,
> +                    netdev_features_t features)
> +{
> +       return vxlan_features_check(skb, features);
> +}

Do you know what the actual capabilities of the device are? My guess
is that in practice you can have a more liberal feature check and
support a greater range of protocols. Something like this:
https://patchwork.ozlabs.org/patch/461323/

Also, does this patch support TSO or just checksums? It looks like
checksums only but in that case it shouldn't expose
NETIF_F_GSO_UDP_TUNNEL.
Rustad, Mark D June 11, 2015, 4:35 p.m. UTC | #2 
> On Jun 10, 2015, at 11:58 AM, Jesse Gross <jesse@nicira.com> wrote:
> 
> On Wed, Jun 10, 2015 at 10:44 AM, Mark D Rustad <mark.d.rustad@intel.com> wrote:
>> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
>> index 03336013a76c..3c9bc7cc7d10 100644
>> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
>> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
>> +static netdev_features_t
>> +ixgbe_features_check(struct sk_buff *skb, struct net_device *dev,
>> +                    netdev_features_t features)
>> +{
>> +       return vxlan_features_check(skb, features);
>> +}
> 
> Do you know what the actual capabilities of the device are? My guess
> is that in practice you can have a more liberal feature check and
> support a greater range of protocols. Something like this:
> https://patchwork.ozlabs.org/patch/461323/

I will look further into this. With the number of devices involved it will take me some time.

> Also, does this patch support TSO or just checksums?

It relies on GSO for segmentation so the hardware can do the checksumming.

> It looks like
> checksums only but in that case it shouldn't expose
> NETIF_F_GSO_UDP_TUNNEL.

I thought that was what I needed to set to get GSO to be used on the tunnel. If that isn't what this does, it is very badly-named.

--
Mark Rustad, Networking Division, Intel Corporation
diff mbox

Patch

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 03336013a76c..3c9bc7cc7d10 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -6926,31 +6926,55 @@  static void ixgbe_tx_csum(struct ixgbe_ring *tx_ring,
 		if (!(first->tx_flags & IXGBE_TX_FLAGS_HW_VLAN) &&
 		    !(first->tx_flags & IXGBE_TX_FLAGS_CC))
 			return;
+		vlan_macip_lens = skb_network_offset(skb) <<
+				  IXGBE_ADVTXD_MACLEN_SHIFT;
 	} else {
 		u8 l4_hdr = 0;
-		switch (first->protocol) {
-		case htons(ETH_P_IP):
-			vlan_macip_lens |= skb_network_header_len(skb);
+		union {
+			struct iphdr *ipv4;
+			struct ipv6hdr *ipv6;
+			u8 *raw;
+		} network_hdr;
+		union {
+			struct tcphdr *tcphdr;
+			u8 *raw;
+		} transport_hdr;
+
+		if (skb->encapsulation) {
+			network_hdr.raw = skb_inner_network_header(skb);
+			transport_hdr.raw = skb_inner_transport_header(skb);
+			vlan_macip_lens = skb_inner_network_offset(skb) <<
+					  IXGBE_ADVTXD_MACLEN_SHIFT;
+		} else {
+			network_hdr.raw = skb_network_header(skb);
+			transport_hdr.raw = skb_transport_header(skb);
+			vlan_macip_lens = skb_network_offset(skb) <<
+					  IXGBE_ADVTXD_MACLEN_SHIFT;
+		}
+
+		/* use first 4 bits to determine IP version */
+		switch (network_hdr.ipv4->version) {
+		case IPVERSION:
+			vlan_macip_lens |= transport_hdr.raw - network_hdr.raw;
 			type_tucmd |= IXGBE_ADVTXD_TUCMD_IPV4;
-			l4_hdr = ip_hdr(skb)->protocol;
+			l4_hdr = network_hdr.ipv4->protocol;
 			break;
-		case htons(ETH_P_IPV6):
-			vlan_macip_lens |= skb_network_header_len(skb);
-			l4_hdr = ipv6_hdr(skb)->nexthdr;
+		case 6:
+			vlan_macip_lens |= transport_hdr.raw - network_hdr.raw;
+			l4_hdr = network_hdr.ipv6->nexthdr;
 			break;
 		default:
 			if (unlikely(net_ratelimit())) {
 				dev_warn(tx_ring->dev,
-				 "partial checksum but proto=%x!\n",
-				 first->protocol);
+					 "partial checksum but version=%d\n",
+					 network_hdr.ipv4->version);
 			}
-			break;
 		}
 
 		switch (l4_hdr) {
 		case IPPROTO_TCP:
 			type_tucmd |= IXGBE_ADVTXD_TUCMD_L4T_TCP;
-			mss_l4len_idx = tcp_hdrlen(skb) <<
+			mss_l4len_idx = (transport_hdr.tcphdr->doff * 4) <<
 					IXGBE_ADVTXD_L4LEN_SHIFT;
 			break;
 		case IPPROTO_SCTP:
@@ -6976,7 +7000,6 @@  static void ixgbe_tx_csum(struct ixgbe_ring *tx_ring,
 	}
 
 	/* vlan_macip_lens: MACLEN, VLAN tag */
-	vlan_macip_lens |= skb_network_offset(skb) << IXGBE_ADVTXD_MACLEN_SHIFT;
 	vlan_macip_lens |= first->tx_flags & IXGBE_TX_FLAGS_VLAN_MASK;
 
 	ixgbe_tx_ctxtdesc(tx_ring, vlan_macip_lens, 0,
@@ -8220,6 +8243,13 @@  static void ixgbe_fwd_del(struct net_device *pdev, void *priv)
 	kfree(fwd_adapter);
 }
 
+static netdev_features_t
+ixgbe_features_check(struct sk_buff *skb, struct net_device *dev,
+		     netdev_features_t features)
+{
+	return vxlan_features_check(skb, features);
+}
+
 static const struct net_device_ops ixgbe_netdev_ops = {
 	.ndo_open		= ixgbe_open,
 	.ndo_stop		= ixgbe_close,
@@ -8268,6 +8298,7 @@  static const struct net_device_ops ixgbe_netdev_ops = {
 	.ndo_dfwd_del_station	= ixgbe_fwd_del,
 	.ndo_add_vxlan_port	= ixgbe_add_vxlan_port,
 	.ndo_del_vxlan_port	= ixgbe_del_vxlan_port,
+	.ndo_features_check	= ixgbe_features_check,
 };
 
 /**
@@ -8600,6 +8631,7 @@  skip_sriov:
 			   NETIF_F_HW_VLAN_CTAG_RX |
 			   NETIF_F_TSO |
 			   NETIF_F_TSO6 |
+			   NETIF_F_GSO_UDP_TUNNEL |
 			   NETIF_F_RXHASH |
 			   NETIF_F_RXCSUM;
 
@@ -8627,6 +8659,10 @@  skip_sriov:
 	netdev->vlan_features |= NETIF_F_IPV6_CSUM;
 	netdev->vlan_features |= NETIF_F_SG;
 
+	netdev->hw_enc_features |= NETIF_F_SG | NETIF_F_IP_CSUM |
+				   NETIF_F_GSO_UDP_TUNNEL |
+				   NETIF_F_IPV6_CSUM;
+
 	netdev->priv_flags |= IFF_UNICAST_FLT;
 	netdev->priv_flags |= IFF_SUPP_NOFCS;