[PATCH v3 net-next 0/2] Enable Big TCP for MANA devices

[PATCH v3 net-next 0/2] Enable Big TCP for MANA devices

[Shradha Gupta]

Allow the max gso/gro aggregated pkt size to go up to GSO_MAX_SIZE for
MANA NIC. On Azure, this not possible without allowing the same for
netvsc NIC (as the NICs are bonded together).
Therefore, we use netif_set_tso_max_size() to set max aggregated pkt
size
to VF's tso_max_size for netvsc too, when the data path is switched over
to the VF

The first patch allows MANA to configure aggregated pkt size of up-to
GSO_MAX_SIZE

The second patch enables the same on the netvsc NIC, if the data path
for the bonded NIC is switched to the VF

---
 Changes in v3
 * Add ipv6_hopopt_jumbo_remove() while sending Big TCP packets
---
  Changes in v2
  * Instead of using 'tcp segment' throughout the patch used the words
    'aggregated pkt size'
---

Shradha Gupta (2):
  net: mana: Allow tso_max_size to go up-to GSO_MAX_SIZE
  hv_netvsc: Use VF's tso_max_size value when data path is VF

 drivers/net/ethernet/microsoft/mana/mana_en.c |  5 +++++
 drivers/net/hyperv/hyperv_net.h               |  2 ++
 drivers/net/hyperv/netvsc_drv.c               | 15 +++++++++++++++
 drivers/net/hyperv/rndis_filter.c             | 13 +++++++------
 4 files changed, 29 insertions(+), 6 deletions(-)

-- 
2.34.1

[PATCH v3 net-next 1/2] net: mana: Allow tso_max_size to go up-to GSO_MAX_SIZE

[Shradha Gupta]

Allow the max aggregated pkt size to go up-to GSO_MAX_SIZE for MANA NIC.
This patch only increases the max allowable gso/gro pkt size for MANA
devices and does not change the defaults.
Following are the perf benefits by increasing the pkt aggregate size from
legacy gso_max_size value(64K) to newer one(up-to 511K

IPv4 tests
for i in {1..10}; do netperf -t TCP_RR  -H 10.0.0.5 -p50000 -- -r80000,80000
-O MIN_LATENCY,P90_LATENCY,P99_LATENCY,THROUGHPUT|tail -1; done

min	p90	p99	Throughput		gso_max_size
93	171	194	6594.25
97	154	180	7183.74
95	165	189	6927.86
96	165	188	6976.04
93	154	185	7338.05			64K
93	168	189	6938.03
94	169	189	6784.93
92	166	189	7117.56
94	179	191	6678.44
95	157	183	7277.81

min	p90	p99	Throughput
93	134	146	8448.75
95	134	140	8396.54
94	137	148	8204.12
94	137	148	8244.41
94	128	139	8666.52			80K
94	141	153	8116.86
94	138	149	8163.92
92	135	142	8362.72
92	134	142	8497.57
93	136	148	8393.23

IPv6 Tests
for i in {1..10}; do netperf -t TCP_RR  -H fd00:9013:cadd::4 -p50000 --
-r80000,80000 -O MIN_LATENCY,P90_LATENCY,P99_LATENCY,THROUGHPUT|tail -1; done

min	p90	p99	Throughput		gso_max_size
108	165	170	6673.2
101	169	189	6451.69
101	165	169	6737.65
102	167	175	6614.64
101	178	189	6247.13			64K
107	163	169	6678.63
106	176	187	6350.86
100	164	169	6617.36
102	163	170	6849.21
102	168	175	6605.7

min	p90	p99	Throughput
108	155	166	7183			
110	154	163	7268.87			
109	152	159	7434.35			
107	145	157	7569.15			
107	149	164	7496.17			80K
110	154	159	7245.85			
108	156	162	7266.24			
109	145	158	7526.66			
106	145	151	7785.75			
111	148	157	7246.65			


Tested on azure env with Accelerated Networking enabled and disabled.

Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 Changes in v3
 * Add ipv6_hopopt_jumbo_remove() while sending Big TCP packets
---
 Changes in v2
 * Instead of using 'tcp segment' throughout the patch used more accurate
   term 'aggregated pkt size'
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index aa1e47233fe5..3b0fb4d95cf7 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -256,6 +256,9 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	if (skb_cow_head(skb, MANA_HEADROOM))
 		goto tx_drop_count;
 
+	if (unlikely(ipv6_hopopt_jumbo_remove(skb)))
+		goto tx_drop_count;
+
 	txq = &apc->tx_qp[txq_idx].txq;
 	gdma_sq = txq->gdma_sq;
 	cq = &apc->tx_qp[txq_idx].tx_cq;
@@ -2873,6 +2876,8 @@ static int mana_probe_port(struct mana_context *ac, int port_idx,
 	ndev->dev_port = port_idx;
 	SET_NETDEV_DEV(ndev, gc->dev);
 
+	netif_set_tso_max_size(ndev, GSO_MAX_SIZE);
+
 	netif_carrier_off(ndev);
 
 	netdev_rss_key_fill(apc->hashkey, MANA_HASH_KEY_SIZE);
-- 
2.34.1

[PATCH v3 net-next 2/2] hv_netvsc: Use VF's tso_max_size value when data path is VF

[Shradha Gupta]

On Azure, increasing VF's gso/gro packet size to up-to GSO_MAX_SIZE
is not possible without allowing the same for netvsc NIC
(as the NICs are bonded together). For bonded NICs, the min of the max
aggregated pkt size of the members is propagated in the stack.

Therefore, we use netif_set_tso_max_size() to set max aggregated pkt size
to VF's packet size for netvsc too, when the data path is switched over
to the VF
Tested on azure env with Accelerated Networking enabled and disabled.

Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 Changes in v2
 * Instead of using 'tcp segment' throughout the patch used more accurate
   term 'aggregated pkt size'
---
 drivers/net/hyperv/hyperv_net.h   |  2 ++
 drivers/net/hyperv/netvsc_drv.c   | 15 +++++++++++++++
 drivers/net/hyperv/rndis_filter.c | 13 +++++++------
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index e690b95b1bbb..def41067ea3f 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -1166,6 +1166,8 @@ struct netvsc_device {
 	u32 max_chn;
 	u32 num_chn;
 
+	u32 netvsc_gso_max_size;
+
 	atomic_t open_chn;
 	struct work_struct subchan_work;
 	wait_queue_head_t subchan_open;
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index d6c4abfc3a28..cbb517aa59cf 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2461,6 +2461,21 @@ static int netvsc_vf_changed(struct net_device *vf_netdev, unsigned long event)
 	} else {
 		netdev_info(ndev, "Data path switched %s VF: %s\n",
 			    vf_is_up ? "to" : "from", vf_netdev->name);
+
+		/* In Azure, when accelerated networking in enabled, other NICs
+		 * like MANA, MLX, are configured as a bonded nic with
+		 * Netvsc(failover) NIC. For bonded NICs, the min of the max
+		 * pkt aggregate size of the members is propagated in the stack.
+		 * In order to allow these NICs (MANA/MLX) to use up to
+		 * GSO_MAX_SIZE gso packet size, we need to allow Netvsc NIC to
+		 * also support this in the guest.
+		 * This value is only increased for netvsc NIC when datapath is
+		 * switched over to the VF
+		 */
+		if (vf_is_up)
+			netif_set_tso_max_size(ndev, vf_netdev->tso_max_size);
+		else
+			netif_set_tso_max_size(ndev, netvsc_dev->netvsc_gso_max_size);
 	}
 
 	return NOTIFY_OK;
diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c
index c0ceeef4fcd8..82747dfacd70 100644
--- a/drivers/net/hyperv/rndis_filter.c
+++ b/drivers/net/hyperv/rndis_filter.c
@@ -1356,9 +1356,10 @@ static int rndis_netdev_set_hwcaps(struct rndis_device *rndis_device,
 	struct net_device_context *net_device_ctx = netdev_priv(net);
 	struct ndis_offload hwcaps;
 	struct ndis_offload_params offloads;
-	unsigned int gso_max_size = GSO_LEGACY_MAX_SIZE;
 	int ret;
 
+	nvdev->netvsc_gso_max_size = GSO_LEGACY_MAX_SIZE;
+
 	/* Find HW offload capabilities */
 	ret = rndis_query_hwcaps(rndis_device, nvdev, &hwcaps);
 	if (ret != 0)
@@ -1390,8 +1391,8 @@ static int rndis_netdev_set_hwcaps(struct rndis_device *rndis_device,
 			offloads.lso_v2_ipv4 = NDIS_OFFLOAD_PARAMETERS_LSOV2_ENABLED;
 			net->hw_features |= NETIF_F_TSO;
 
-			if (hwcaps.lsov2.ip4_maxsz < gso_max_size)
-				gso_max_size = hwcaps.lsov2.ip4_maxsz;
+			if (hwcaps.lsov2.ip4_maxsz < nvdev->netvsc_gso_max_size)
+				nvdev->netvsc_gso_max_size = hwcaps.lsov2.ip4_maxsz;
 		}
 
 		if (hwcaps.csum.ip4_txcsum & NDIS_TXCSUM_CAP_UDP4) {
@@ -1411,8 +1412,8 @@ static int rndis_netdev_set_hwcaps(struct rndis_device *rndis_device,
 			offloads.lso_v2_ipv6 = NDIS_OFFLOAD_PARAMETERS_LSOV2_ENABLED;
 			net->hw_features |= NETIF_F_TSO6;
 
-			if (hwcaps.lsov2.ip6_maxsz < gso_max_size)
-				gso_max_size = hwcaps.lsov2.ip6_maxsz;
+			if (hwcaps.lsov2.ip6_maxsz < nvdev->netvsc_gso_max_size)
+				nvdev->netvsc_gso_max_size = hwcaps.lsov2.ip6_maxsz;
 		}
 
 		if (hwcaps.csum.ip6_txcsum & NDIS_TXCSUM_CAP_UDP6) {
@@ -1438,7 +1439,7 @@ static int rndis_netdev_set_hwcaps(struct rndis_device *rndis_device,
 	 */
 	net->features &= ~NETVSC_SUPPORTED_HW_FEATURES | net->hw_features;
 
-	netif_set_tso_max_size(net, gso_max_size);
+	netif_set_tso_max_size(net, nvdev->netvsc_gso_max_size);
 
 	ret = rndis_filter_set_offload_params(net, nvdev, &offloads);
 
-- 
2.34.1

Re: [PATCH v3 net-next 0/2] Enable Big TCP for MANA devices

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by David S. Miller <davem@davemloft.net>:

On Sun, 16 Feb 2025 19:41:55 -0800 you wrote:
> Allow the max gso/gro aggregated pkt size to go up to GSO_MAX_SIZE for
> MANA NIC. On Azure, this not possible without allowing the same for
> netvsc NIC (as the NICs are bonded together).
> Therefore, we use netif_set_tso_max_size() to set max aggregated pkt
> size
> to VF's tso_max_size for netvsc too, when the data path is switched over
> to the VF
> 
> [...]

Here is the summary with links:
  - [v3,net-next,1/2] net: mana: Allow tso_max_size to go up-to GSO_MAX_SIZE
    https://git.kernel.org/netdev/net-next/c/27315836f4bc
  - [v3,net-next,2/2] hv_netvsc: Use VF's tso_max_size value when data path is VF
    https://git.kernel.org/netdev/net-next/c/685920920e3d

You are awesome, thank you!
-- 
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