Merge branch 'net-mlx5e-add-support-for-devmem-and-io_uring-tcp-zero-copy'

Merge branch 'net-mlx5e-add-support-for-devmem-and-io_uring-tcp-zero-copy'

Mark Bloch says:

====================
net/mlx5e: Add support for devmem and io_uring TCP zero-copy

This series adds support for zerocopy rx TCP with devmem and io_uring
for ConnectX7 NICs and above. For performance reasons and simplicity
HW-GRO will also be turned on when header-data split mode is on.

Performance
===========

Test setup:

* CPU: Intel(R) Xeon(R) Platinum 8380 CPU @ 2.30GHz (single NUMA)
* NIC: ConnectX7
* Benchmarking tool: kperf [0]
* Single TCP flow
* Test duration: 60s

With application thread and interrupts pinned to the *same* core:

|------+-----------+----------|
| MTU  | epoll     | io_uring |
|------+-----------+----------|
| 1500 | 61.6 Gbps | 114 Gbps |
| 4096 | 69.3 Gbps | 151 Gbps |
| 9000 | 67.8 Gbps | 187 Gbps |
|------+-----------+----------|

The CPU usage for io_uring is 95%.

Reproduction steps for io_uring:

server --no-daemon -a 2001:db8::1 --no-memcmp --iou --iou_sendzc \
	--iou_zcrx --iou_dev_name eth2 --iou_zcrx_queue_id 2

server --no-daemon -a 2001:db8::2 --no-memcmp --iou --iou_sendzc

client --src 2001:db8::2 --dst 2001:db8::1 \
	--msg-zerocopy -t 60 --cpu-min=2 --cpu-max=2

Patch overview:
================

First, a netmem API for skb_can_coalesce is added to the core to be able
to do skb fragment coalescing on netmems.

The next patches introduce some cleanups in the internal SHAMPO code and
improvements to hw gro capability checks in FW.

A separate page_pool is introduced for headers, to be used only when
the rxq has a memory provider.

Then the driver is converted to use the netmem API and to allow support
for unreadable netmem page pool.

The queue management ops are implemented.

Finally, the tcp-data-split ring parameter is exposed.
References
==========
[0] kperf: git://git.kernel.dk/kperf.git
v1: https://lore.kernel.org/20250116215530.158886-1-saeed@kernel.org
v2: https://lore.kernel.org/1747950086-1246773-1-git-send-email-tariqt@nvidia.com
v3: https://lore.kernel.org/20250609145833.990793-1-mbloch@nvidia.com
v4: https://lore.kernel.org/20250610150950.1094376-1-mbloch@nvidia.com
v5: https://lore.kernel.org/20250612154648.1161201-1-mbloch@nvidia.com
====================

Link: https://patch.msgid.link/20250616141441.1243044-1-mbloch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>