[net-next PATCH v3 0/8] Fix Tunnel features and enable GSO partial for several drivers

[net-next PATCH v3 0/8] Fix Tunnel features and enable GSO partial for several drivers

[Alexander Duyck]

This patch series is meant to allow us to get the best performance possible
for Mellanox ConnectX-3/4 and Broadcom NetXtreme-C/E adapters in terms of
VXLAN and GRE tunnels.

The first 3 patches address issues I found in regards to GSO_PARTIAL and
TSO_MANGLEID.

The next 4 patches go through and enable GSO_PARTIAL for VXLAN tunnels that
have an outer checksum enabled, and then enable IPv6 support where I can.
One outstanding issue is that I wasn't able to get offloads working with
outer IPv6 headers on mlx4.  However that wasn't a feature that was enabled
before so it isn't technically a regression, however I believe Engineers
from Mellanox said they would look into it since they thought it should be
supported.

The last patch enables GSO_PARTIAL for VXLAN and GRE tunnels on the bnxt
driver.  One piece of feedback I received on the patch was that the
hardware has globally set IPv6 UDP tunnels to always have the checksum
field computed.  I plan to work with Broadcom to get that addressed so that
we only populate the checksum field if it was requested by the network
stack.

v2: Rebased patches off of latest changes to the mlx4/mlx5 drivers.
    Added bnxt driver patch as I received feedback on the RFC.
v3: Moved 2 patches into series for net as they were generic fixes.
    Added patch to disable GSO partial if frame is less than 2x size of MSS

    There are outstanding issues as called out above that need to be
    addressed, however they were present before these patches so it isn't
    as if they introduce a regression.  In addition gains can be easily
    seen so there should be no issue with applying the driver patches while
    the IPv6 mlx4_en and bnxt issues are being researched.

---

Alexander Duyck (8):
      gso: Do not perform partial GSO if number of partial segments is 1 or less
      gso: Only allow GSO_PARTIAL if we can checksum the inner protocol
      net: Fix netdev_fix_features so that TSO_MANGLEID is only available with TSO
      net/mlx4_en: Add support for UDP tunnel segmentation with outer checksum offload
      net/mlx4_en: Add support for inner IPv6 checksum offloads and TSO
      net/mlx5e: Add support for UDP tunnel segmentation with outer checksum offload
      net/mlx5e: Fix IPv6 tunnel checksum offload
      bnxt: Add support for segmentation of tunnels with outer checksums


 drivers/net/ethernet/broadcom/bnxt/bnxt.c         |    9 ++++-
 drivers/net/ethernet/mellanox/mlx4/en_netdev.c    |   38 +++++++++++++++++----
 drivers/net/ethernet/mellanox/mlx4/en_tx.c        |   15 +++++++-
 drivers/net/ethernet/mellanox/mlx5/core/en_main.c |   10 ++++--
 net/core/dev.c                                    |    4 ++
 net/core/skbuff.c                                 |   11 ++++--
 6 files changed, 69 insertions(+), 18 deletions(-)

[net-next PATCH v3 1/8] gso: Do not perform partial GSO if number of partial segments is 1 or less

[Alexander Duyck]

In the event that the number of partial segments is equal to 1 we don't
really need to perform partial segmentation offload.  As such we should
skip multiplying the MSS and instead just clear the partial_segs value
since it will not provide any gain to advertise the frame as being GSO when
it is a single frame.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
---
 net/core/skbuff.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 7a1d48983f81..b8dd2d2e2256 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3101,7 +3101,10 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
 	 */
 	if (features & NETIF_F_GSO_PARTIAL) {
 		partial_segs = len / mss;
-		mss *= partial_segs;
+		if (partial_segs > 1)
+			mss *= partial_segs;
+		else
+			partial_segs = 0;
 	}
 
 	headroom = skb_headroom(head_skb);

[net-next PATCH v3 2/8] gso: Only allow GSO_PARTIAL if we can checksum the inner protocol

[Alexander Duyck]

This patch addresses a possible issue that can occur if we get into any odd
corner cases where we support TSO for a given protocol but not the checksum
or scatter-gather offload.  There are few drivers floating around that
setup their tunnels this way and by enforcing the checksum piece we can
avoid mangling any frames.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
---
 net/core/skbuff.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index b8dd2d2e2256..5586be93632f 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3080,8 +3080,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
 	unsigned int headroom;
 	unsigned int len = head_skb->len;
 	__be16 proto;
-	bool csum;
-	int sg = !!(features & NETIF_F_SG);
+	bool csum, sg;
 	int nfrags = skb_shinfo(head_skb)->nr_frags;
 	int err = -ENOMEM;
 	int i = 0;
@@ -3093,13 +3092,14 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
 	if (unlikely(!proto))
 		return ERR_PTR(-EINVAL);
 
+	sg = !!(features & NETIF_F_SG);
 	csum = !!can_checksum_protocol(features, proto);
 
 	/* GSO partial only requires that we trim off any excess that
 	 * doesn't fit into an MSS sized block, so take care of that
 	 * now.
 	 */
-	if (features & NETIF_F_GSO_PARTIAL) {
+	if (sg && csum && (features & NETIF_F_GSO_PARTIAL)) {
 		partial_segs = len / mss;
 		if (partial_segs > 1)
 			mss *= partial_segs;

[net-next PATCH v3 3/8] net: Fix netdev_fix_features so that TSO_MANGLEID is only available with TSO

[Alexander Duyck]

This change makes it so that we will strip the TSO_MANGLEID bit if TSO is
not present.  This way we will also handle ECN correctly of TSO is not
present.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
---
 net/core/dev.c |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/core/dev.c b/net/core/dev.c
index 673d1f118bfb..e98ba63fe280 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6721,6 +6721,10 @@ static netdev_features_t netdev_fix_features(struct net_device *dev,
 		features &= ~NETIF_F_TSO6;
 	}
 
+	/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
+	if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
+		features &= ~NETIF_F_TSO_MANGLEID;
+
 	/* TSO ECN requires that TSO is present as well. */
 	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
 		features &= ~NETIF_F_TSO_ECN;

[net-next PATCH v3 4/8] net/mlx4_en: Add support for UDP tunnel segmentation with outer checksum offload

[Alexander Duyck]

This patch assumes that the mlx4 hardware will ignore existing IPv4/v6
header fields for length and checksum as well as the length and checksum
fields for outer UDP headers.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_netdev.c |   17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index 8bd143dda95d..bce37cbfde24 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -2358,7 +2358,9 @@ out:
 
 	/* set offloads */
 	priv->dev->hw_enc_features |= NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
-				      NETIF_F_TSO | NETIF_F_GSO_UDP_TUNNEL;
+				      NETIF_F_TSO | NETIF_F_GSO_UDP_TUNNEL |
+				      NETIF_F_GSO_UDP_TUNNEL_CSUM |
+				      NETIF_F_GSO_PARTIAL;
 }
 
 static void mlx4_en_del_vxlan_offloads(struct work_struct *work)
@@ -2368,7 +2370,9 @@ static void mlx4_en_del_vxlan_offloads(struct work_struct *work)
 						 vxlan_del_task);
 	/* unset offloads */
 	priv->dev->hw_enc_features &= ~(NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
-				      NETIF_F_TSO | NETIF_F_GSO_UDP_TUNNEL);
+					NETIF_F_TSO | NETIF_F_GSO_UDP_TUNNEL |
+					NETIF_F_GSO_UDP_TUNNEL_CSUM |
+					NETIF_F_GSO_PARTIAL);
 
 	ret = mlx4_SET_PORT_VXLAN(priv->mdev->dev, priv->port,
 				  VXLAN_STEER_BY_OUTER_MAC, 0);
@@ -2992,8 +2996,13 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
 	}
 
 	if (mdev->dev->caps.tunnel_offload_mode == MLX4_TUNNEL_OFFLOAD_MODE_VXLAN) {
-		dev->hw_features |= NETIF_F_GSO_UDP_TUNNEL;
-		dev->features    |= NETIF_F_GSO_UDP_TUNNEL;
+		dev->hw_features |= NETIF_F_GSO_UDP_TUNNEL |
+				    NETIF_F_GSO_UDP_TUNNEL_CSUM |
+				    NETIF_F_GSO_PARTIAL;
+		dev->features    |= NETIF_F_GSO_UDP_TUNNEL |
+				    NETIF_F_GSO_UDP_TUNNEL_CSUM |
+				    NETIF_F_GSO_PARTIAL;
+		dev->gso_partial_features = NETIF_F_GSO_UDP_TUNNEL_CSUM;
 	}
 
 	mdev->pndev[port] = dev;

[net-next PATCH v3 5/8] net/mlx4_en: Add support for inner IPv6 checksum offloads and TSO

[Alexander Duyck]

>From what I can tell the ConnectX-3 will support an inner IPv6 checksum and
segmentation offload, however it cannot support outer IPv6 headers.  This
assumption is based on the fact that I could see the checksum being
offloaded for inner header on IPv4 tunnels, but not on IPv6 tunnels.

For this reason I am adding the feature to the hw_enc_features and adding
an extra check to the features_check call that will disable GSO and
checksum offload in the case that the encapsulated frame has an outer IP
version of that is not 4.  The check in mlx4_en_features_check could be
removed if at some point in the future a fix is found that allows the
hardware to offload segmentation/checksum on tunnels with an outer IPv6
header.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_netdev.c |   25 +++++++++++++++++++-----
 drivers/net/ethernet/mellanox/mlx4/en_tx.c     |   15 ++++++++++++--
 2 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index bce37cbfde24..6f28ac58251c 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -2357,8 +2357,10 @@ out:
 	}
 
 	/* set offloads */
-	priv->dev->hw_enc_features |= NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
-				      NETIF_F_TSO | NETIF_F_GSO_UDP_TUNNEL |
+	priv->dev->hw_enc_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
+				      NETIF_F_RXCSUM |
+				      NETIF_F_TSO | NETIF_F_TSO6 |
+				      NETIF_F_GSO_UDP_TUNNEL |
 				      NETIF_F_GSO_UDP_TUNNEL_CSUM |
 				      NETIF_F_GSO_PARTIAL;
 }
@@ -2369,8 +2371,10 @@ static void mlx4_en_del_vxlan_offloads(struct work_struct *work)
 	struct mlx4_en_priv *priv = container_of(work, struct mlx4_en_priv,
 						 vxlan_del_task);
 	/* unset offloads */
-	priv->dev->hw_enc_features &= ~(NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
-					NETIF_F_TSO | NETIF_F_GSO_UDP_TUNNEL |
+	priv->dev->hw_enc_features &= ~(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
+					NETIF_F_RXCSUM |
+					NETIF_F_TSO | NETIF_F_TSO6 |
+					NETIF_F_GSO_UDP_TUNNEL |
 					NETIF_F_GSO_UDP_TUNNEL_CSUM |
 					NETIF_F_GSO_PARTIAL);
 
@@ -2431,7 +2435,18 @@ static netdev_features_t mlx4_en_features_check(struct sk_buff *skb,
 						netdev_features_t features)
 {
 	features = vlan_features_check(skb, features);
-	return vxlan_features_check(skb, features);
+	features = vxlan_features_check(skb, features);
+
+	/* The ConnectX-3 doesn't support outer IPv6 checksums but it does
+	 * support inner IPv6 checksums and segmentation so  we need to
+	 * strip that feature if this is an IPv6 encapsulated frame.
+	 */
+	if (skb->encapsulation &&
+	    (skb->ip_summed == CHECKSUM_PARTIAL) &&
+	    (ip_hdr(skb)->version != 4))
+		features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
+
+	return features;
 }
 #endif
 
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index a386f047c1af..0f206a95429c 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -41,6 +41,7 @@
 #include <linux/vmalloc.h>
 #include <linux/tcp.h>
 #include <linux/ip.h>
+#include <linux/ipv6.h>
 #include <linux/moduleparam.h>
 
 #include "mlx4_en.h"
@@ -920,8 +921,18 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
 				 tx_ind, fragptr);
 
 	if (skb->encapsulation) {
-		struct iphdr *ipv4 = (struct iphdr *)skb_inner_network_header(skb);
-		if (ipv4->protocol == IPPROTO_TCP || ipv4->protocol == IPPROTO_UDP)
+		union {
+			struct iphdr *v4;
+			struct ipv6hdr *v6;
+			unsigned char *hdr;
+		} ip;
+		u8 proto;
+
+		ip.hdr = skb_inner_network_header(skb);
+		proto = (ip.v4->version == 4) ? ip.v4->protocol :
+						ip.v6->nexthdr;
+
+		if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP | MLX4_WQE_CTRL_ILP);
 		else
 			op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP);

[net-next PATCH v3 6/8] net/mlx5e: Add support for UDP tunnel segmentation with outer checksum offload

[Alexander Duyck]

This patch assumes that the mlx5 hardware will ignore existing IPv4/v6
header fields for length and checksum as well as the length and checksum
fields for outer UDP headers.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_main.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 4ccfc1ac62c5..2d6aaad77d62 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -2803,13 +2803,18 @@ static void mlx5e_build_netdev(struct net_device *netdev)
 	netdev->hw_features      |= NETIF_F_HW_VLAN_CTAG_FILTER;
 
 	if (mlx5e_vxlan_allowed(mdev)) {
-		netdev->hw_features     |= NETIF_F_GSO_UDP_TUNNEL;
+		netdev->hw_features     |= NETIF_F_GSO_UDP_TUNNEL |
+					   NETIF_F_GSO_UDP_TUNNEL_CSUM |
+					   NETIF_F_GSO_PARTIAL;
 		netdev->hw_enc_features |= NETIF_F_IP_CSUM;
 		netdev->hw_enc_features |= NETIF_F_RXCSUM;
 		netdev->hw_enc_features |= NETIF_F_TSO;
 		netdev->hw_enc_features |= NETIF_F_TSO6;
 		netdev->hw_enc_features |= NETIF_F_RXHASH;
 		netdev->hw_enc_features |= NETIF_F_GSO_UDP_TUNNEL;
+		netdev->hw_enc_features |= NETIF_F_GSO_UDP_TUNNEL_CSUM |
+					   NETIF_F_GSO_PARTIAL;
+		netdev->gso_partial_features = NETIF_F_GSO_UDP_TUNNEL_CSUM;
 	}
 
 	mlx5_query_port_fcs(mdev, &fcs_supported, &fcs_enabled);

[net-next PATCH v3 7/8] net/mlx5e: Fix IPv6 tunnel checksum offload

[Alexander Duyck]

The mlx5 driver exposes support for TSO6 but not IPv6 csum for hardware
encapsulated tunnels.  This leads to issues as it triggers warnings in
skb_checksum_help as it ends up being called as we report supporting the
segmentation but not the checksumming for IPv6 frames.

This patch corrects that and drops 2 features that don't actually need to
be supported in hw_enc_features since they are Rx features and don't
actually impact anything by being present in hw_enc_features.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_main.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 2d6aaad77d62..409916c18b86 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -2807,10 +2807,9 @@ static void mlx5e_build_netdev(struct net_device *netdev)
 					   NETIF_F_GSO_UDP_TUNNEL_CSUM |
 					   NETIF_F_GSO_PARTIAL;
 		netdev->hw_enc_features |= NETIF_F_IP_CSUM;
-		netdev->hw_enc_features |= NETIF_F_RXCSUM;
+		netdev->hw_enc_features |= NETIF_F_IPV6_CSUM;
 		netdev->hw_enc_features |= NETIF_F_TSO;
 		netdev->hw_enc_features |= NETIF_F_TSO6;
-		netdev->hw_enc_features |= NETIF_F_RXHASH;
 		netdev->hw_enc_features |= NETIF_F_GSO_UDP_TUNNEL;
 		netdev->hw_enc_features |= NETIF_F_GSO_UDP_TUNNEL_CSUM |
 					   NETIF_F_GSO_PARTIAL;

[net-next PATCH v3 8/8] bnxt: Add support for segmentation of tunnels with outer checksums

[Alexander Duyck]

This patch assumes that the bnxt hardware will ignore existing IPv4/v6
header fields for length and checksum as well as the length and checksum
fields for outer UDP and GRE headers.

I have been told by Michael Chan that this is working.  Though this might
be somewhat redundant for IPv6 as they are forcing the checksum to be
computed for all IPv6 frames that are offloaded.  A follow-up patch may be
necessary in order to fix this as it is essentially mangling the outer IPv6
headers to add a checksum where none was requested.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 4645c44e7c15..ae668476fff0 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -6194,14 +6194,19 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 			   NETIF_F_TSO | NETIF_F_TSO6 |
 			   NETIF_F_GSO_UDP_TUNNEL | NETIF_F_GSO_GRE |
 			   NETIF_F_GSO_IPIP | NETIF_F_GSO_SIT |
-			   NETIF_F_RXHASH |
+			   NETIF_F_GSO_UDP_TUNNEL_CSUM | NETIF_F_GSO_GRE_CSUM |
+			   NETIF_F_GSO_PARTIAL | NETIF_F_RXHASH |
 			   NETIF_F_RXCSUM | NETIF_F_LRO | NETIF_F_GRO;
 
 	dev->hw_enc_features =
 			NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | NETIF_F_SG |
 			NETIF_F_TSO | NETIF_F_TSO6 |
 			NETIF_F_GSO_UDP_TUNNEL | NETIF_F_GSO_GRE |
-			NETIF_F_GSO_IPIP | NETIF_F_GSO_SIT;
+			NETIF_F_GSO_UDP_TUNNEL_CSUM | NETIF_F_GSO_GRE_CSUM |
+			NETIF_F_GSO_IPIP | NETIF_F_GSO_SIT |
+			NETIF_F_GSO_PARTIAL;
+	dev->gso_partial_features = NETIF_F_GSO_UDP_TUNNEL_CSUM |
+				    NETIF_F_GSO_GRE_CSUM;
 	dev->vlan_features = dev->hw_features | NETIF_F_HIGHDMA;
 	dev->hw_features |= NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_CTAG_TX |
 			    NETIF_F_HW_VLAN_STAG_RX | NETIF_F_HW_VLAN_STAG_TX;

Re: [net-next PATCH v3 0/8] Fix Tunnel features and enable GSO partial for several drivers

[David Miller]

From: Alexander Duyck <aduyck@mirantis.com>
Date: Mon, 02 May 2016 09:38:06 -0700

> v3: Moved 2 patches into series for net as they were generic fixes.
>     Added patch to disable GSO partial if frame is less than 2x size of MSS

I'll therefore apply this series after my next net --> net-next merge.

Thanks.

Re: [net-next PATCH v3 0/8] Fix Tunnel features and enable GSO partial for several drivers

[David Miller]

From: Alexander Duyck <aduyck@mirantis.com>
Date: Mon, 02 May 2016 09:38:06 -0700

> This patch series is meant to allow us to get the best performance possible
> for Mellanox ConnectX-3/4 and Broadcom NetXtreme-C/E adapters in terms of
> VXLAN and GRE tunnels.

Series applied, thanks Alex.