[PATCH net-next v2 0/3] tun: AF_XDP Tx zero-copy support

[Yunjian Wang]

Hi all:

Now, some drivers support the zero-copy feature of AF_XDP sockets,
which can significantly reduce CPU utilization for XDP programs.

This patch set allows TUN to also support the AF_XDP Tx zero-copy
feature. It is based on Linux 6.8.0+(openEuler 23.09) and has
successfully passed Netperf and Netserver stress testing with
multiple streams between VM A and VM B, using AF_XDP and OVS.

The performance testing was performed on a Intel E5-2620 2.40GHz
machine. Traffic were generated/send through TUN(testpmd txonly
with AF_XDP) to VM (testpmd rxonly in guest).

+------+---------+---------+---------+
|      |   copy  |zero-copy| speedup |
+------+---------+---------+---------+
| UDP  |   Mpps  |   Mpps  |    %    |
| 64   |   2.5   |   4.0   |   60%   |
| 512  |   2.1   |   3.6   |   71%   |
| 1024 |   1.9   |   3.3   |   73%   |
+------+---------+---------+---------+

Yunjian Wang (3):
  xsk: Remove non-zero 'dma_page' check in xp_assign_dev
  vhost_net: Call peek_len when using xdp
  tun: AF_XDP Tx zero-copy support

 drivers/net/tun.c       | 177 ++++++++++++++++++++++++++++++++++++++--
 drivers/vhost/net.c     |  21 +++--
 include/linux/if_tun.h  |  32 ++++++++
 net/xdp/xsk_buff_pool.c |   7 --
 4 files changed, 220 insertions(+), 17 deletions(-)

-- 
2.41.0