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Message-Id: <20220513183408.686447-13-eric.dumazet@gmail.com>
Date: Fri, 13 May 2022 11:34:07 -0700
From: Eric Dumazet <eric.dumazet@...il.com>
To: "David S . Miller" <davem@...emloft.net>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>
Cc: netdev <netdev@...r.kernel.org>,
Alexander Duyck <alexanderduyck@...com>,
Coco Li <lixiaoyan@...gle.com>,
Eric Dumazet <edumazet@...gle.com>,
Eric Dumazet <eric.dumazet@...il.com>,
Tariq Toukan <tariqt@...dia.com>
Subject: [PATCH v7 net-next 12/13] mlx4: support BIG TCP packets
From: Eric Dumazet <edumazet@...gle.com>
mlx4 supports LSOv2 just fine.
IPv6 stack inserts a temporary Hop-by-Hop header
with JUMBO TLV for big packets.
We need to ignore the HBH header when populating TX descriptor.
Tested:
Before: (not enabling bigger TSO/GRO packets)
ip link set dev eth0 gso_max_size 65536 gro_max_size 65536
netperf -H lpaa18 -t TCP_RR -T2,2 -l 10 -Cc -- -r 70000,70000
MIGRATED TCP REQUEST/RESPONSE TEST from ::0 (::) port 0 AF_INET6 to lpaa18.prod.google.com () port 0 AF_INET6 : first burst 0 : cpu bind
Local /Remote
Socket Size Request Resp. Elapsed Trans. CPU CPU S.dem S.dem
Send Recv Size Size Time Rate local remote local remote
bytes bytes bytes bytes secs. per sec % S % S us/Tr us/Tr
262144 540000 70000 70000 10.00 6591.45 0.86 1.34 62.490 97.446
262144 540000
After: (enabling bigger TSO/GRO packets)
ip link set dev eth0 gso_max_size 185000 gro_max_size 185000
netperf -H lpaa18 -t TCP_RR -T2,2 -l 10 -Cc -- -r 70000,70000
MIGRATED TCP REQUEST/RESPONSE TEST from ::0 (::) port 0 AF_INET6 to lpaa18.prod.google.com () port 0 AF_INET6 : first burst 0 : cpu bind
Local /Remote
Socket Size Request Resp. Elapsed Trans. CPU CPU S.dem S.dem
Send Recv Size Size Time Rate local remote local remote
bytes bytes bytes bytes secs. per sec % S % S us/Tr us/Tr
262144 540000 70000 70000 10.00 8383.95 0.95 1.01 54.432 57.584
262144 540000
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
Reviewed-by: Tariq Toukan <tariqt@...dia.com>
Acked-by: Alexander Duyck <alexanderduyck@...com>
---
.../net/ethernet/mellanox/mlx4/en_netdev.c | 3 ++
drivers/net/ethernet/mellanox/mlx4/en_tx.c | 47 +++++++++++++++----
2 files changed, 41 insertions(+), 9 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index c61dc7ae0c056a4dbcf24297549f6b1b5cc25d92..ca4b93a0103469b9629dad2f877a496c23fd727c 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -3417,6 +3417,9 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
dev->min_mtu = ETH_MIN_MTU;
dev->max_mtu = priv->max_mtu;
+ /* supports LSOv2 packets. */
+ netif_set_tso_max_size(dev, GSO_MAX_SIZE);
+
mdev->pndev[port] = dev;
mdev->upper[port] = NULL;
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index f777151d226fb601f52366850f8c86358e214032..af3b2b59a2a6940a2839b277815ec7c3b4af1008 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -43,6 +43,7 @@
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/indirect_call_wrapper.h>
+#include <net/ipv6.h>
#include "mlx4_en.h"
@@ -634,19 +635,28 @@ static int get_real_size(const struct sk_buff *skb,
struct net_device *dev,
int *lso_header_size,
bool *inline_ok,
- void **pfrag)
+ void **pfrag,
+ int *hopbyhop)
{
struct mlx4_en_priv *priv = netdev_priv(dev);
int real_size;
if (shinfo->gso_size) {
*inline_ok = false;
- if (skb->encapsulation)
+ *hopbyhop = 0;
+ if (skb->encapsulation) {
*lso_header_size = (skb_inner_transport_header(skb) - skb->data) + inner_tcp_hdrlen(skb);
- else
+ } else {
+ /* Detects large IPV6 TCP packets and prepares for removal of
+ * HBH header that has been pushed by ip6_xmit(),
+ * mainly so that tcpdump can dissect them.
+ */
+ if (ipv6_has_hopopt_jumbo(skb))
+ *hopbyhop = sizeof(struct hop_jumbo_hdr);
*lso_header_size = skb_transport_offset(skb) + tcp_hdrlen(skb);
+ }
real_size = CTRL_SIZE + shinfo->nr_frags * DS_SIZE +
- ALIGN(*lso_header_size + 4, DS_SIZE);
+ ALIGN(*lso_header_size - *hopbyhop + 4, DS_SIZE);
if (unlikely(*lso_header_size != skb_headlen(skb))) {
/* We add a segment for the skb linear buffer only if
* it contains data */
@@ -873,6 +883,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
int desc_size;
int real_size;
u32 index, bf_index;
+ struct ipv6hdr *h6;
__be32 op_own;
int lso_header_size;
void *fragptr = NULL;
@@ -881,6 +892,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
bool stop_queue;
bool inline_ok;
u8 data_offset;
+ int hopbyhop;
bool bf_ok;
tx_ind = skb_get_queue_mapping(skb);
@@ -890,7 +902,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
goto tx_drop;
real_size = get_real_size(skb, shinfo, dev, &lso_header_size,
- &inline_ok, &fragptr);
+ &inline_ok, &fragptr, &hopbyhop);
if (unlikely(!real_size))
goto tx_drop_count;
@@ -943,7 +955,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
data = &tx_desc->data;
data_offset = offsetof(struct mlx4_en_tx_desc, data);
} else {
- int lso_align = ALIGN(lso_header_size + 4, DS_SIZE);
+ int lso_align = ALIGN(lso_header_size - hopbyhop + 4, DS_SIZE);
data = (void *)&tx_desc->lso + lso_align;
data_offset = offsetof(struct mlx4_en_tx_desc, lso) + lso_align;
@@ -1008,14 +1020,31 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
((ring->prod & ring->size) ?
cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
+ lso_header_size -= hopbyhop;
/* Fill in the LSO prefix */
tx_desc->lso.mss_hdr_size = cpu_to_be32(
shinfo->gso_size << 16 | lso_header_size);
- /* Copy headers;
- * note that we already verified that it is linear */
- memcpy(tx_desc->lso.header, skb->data, lso_header_size);
+ if (unlikely(hopbyhop)) {
+ /* remove the HBH header.
+ * Layout: [Ethernet header][IPv6 header][HBH][TCP header]
+ */
+ memcpy(tx_desc->lso.header, skb->data, ETH_HLEN + sizeof(*h6));
+ h6 = (struct ipv6hdr *)((char *)tx_desc->lso.header + ETH_HLEN);
+ h6->nexthdr = IPPROTO_TCP;
+ /* Copy the TCP header after the IPv6 one */
+ memcpy(h6 + 1,
+ skb->data + ETH_HLEN + sizeof(*h6) +
+ sizeof(struct hop_jumbo_hdr),
+ tcp_hdrlen(skb));
+ /* Leave ipv6 payload_len set to 0, as LSO v2 specs request. */
+ } else {
+ /* Copy headers;
+ * note that we already verified that it is linear
+ */
+ memcpy(tx_desc->lso.header, skb->data, lso_header_size);
+ }
ring->tso_packets++;
i = shinfo->gso_segs;
--
2.36.0.550.gb090851708-goog
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