[net-next,0/4,pull,request] igb: Add support for AF_XDP zero-copy

Message

Tony Nguyen Aug. 8, 2024, 6:35 p.m. UTC

Kurt Kanzenbach says:

Since Sriram's duties changed I am sending this instead. Additionally,
I've tested this on real hardware, Intel i210 [1].

Changes since iwl-next v4:

 - Rebase to v6.10
 - Fix issue reported by kernel test robot
 - Provide napi_id for for xdp_rxq_info_reg() so that busy polling works
 - Set olinfo_status in igb_xmit_zc() so that frames are transmitted

Link to v4: https://lore.kernel.org/intel-wired-lan/[e-mail]/

[1] - https://github.com/Linutronix/TSN-Testbench/tree/main/tests/busypolling_i210

Original cover letter:

The first couple of patches adds helper functions to prepare for AF_XDP
zero-copy support which comes in the last couple of patches, one each
for Rx and TX paths.

As mentioned in v1 patchset [0], I don't have access to an actual IGB
device to provide correct performance numbers. I have used Intel 82576EB
emulator in QEMU [1] to test the changes to IGB driver.

The tests use one isolated vCPU for RX/TX and one isolated vCPU for the
xdp-sock application [2]. Hope these measurements provide at the least
some indication on the increase in performance when using ZC, especially
in the TX path. It would be awesome if someone with a real IGB NIC can
test the patch.

AF_XDP performance using 64 byte packets in Kpps.
Benchmark:	XDP-SKB		XDP-DRV		XDP-DRV(ZC)
rxdrop		220		235		350
txpush		1.000		1.000		410
l2fwd 		1.000		1.000		200

AF_XDP performance using 1500 byte packets in Kpps.
Benchmark:	XDP-SKB		XDP-DRV		XDP-DRV(ZC)
rxdrop		200		210		310
txpush		1.000		1.000		410
l2fwd 		0.900		1.000		160

[0]: https://lore.kernel.org/intel-wired-lan/[e-mail]/
[1]: https://www.qemu.org/docs/master/system/devices/igb.html
[2]: https://github.com/xdp-project/bpf-examples/tree/master/AF_XDP-example
---
iwl-next: https://lore.kernel.org/intel-wired-lan/[e-mail]/

The following are changes since commit 91d516d4de48532d967a77967834e00c8c53dfe6:
  net: mvpp2: Increase size of queue_name buffer
and are available in the git repository at:
  git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue 1GbE

Sriram Yagnaraman (4):
  igb: prepare for AF_XDP zero-copy support
  igb: Introduce XSK data structures and helpers
  igb: add AF_XDP zero-copy Rx support
  igb: add AF_XDP zero-copy Tx support

 drivers/net/ethernet/intel/igb/Makefile   |   2 +-
 drivers/net/ethernet/intel/igb/igb.h      |  35 +-
 drivers/net/ethernet/intel/igb/igb_main.c | 189 ++++++--
 drivers/net/ethernet/intel/igb/igb_xsk.c  | 522 ++++++++++++++++++++++
 4 files changed, 700 insertions(+), 48 deletions(-)
 create mode 100644 drivers/net/ethernet/intel/igb/igb_xsk.c