[v4,0/2] TAP TSO

Message ID 1528821108-12405-1-git-send-email-ophirmu@mellanox.com (mailing list archive)


Ophir Munk June 12, 2018, 4:31 p.m. UTC
- Initial release

- Fixing cksum errors
- TCP segment size refers to TCP payload size (not including l2,l3,l4 headers)

v3 (8 May 2018):
- Bug fixing in case input mbuf is segmented
- Following review comments by Raslan Darawsha

This patch implements TAP TSO (TSP segmentation offload) in SW.
It uses dpdk library librte_gso.
Dpdk librte_gso library segments large TCP payloads (e.g. 64K bytes)
into smaller size buffers.
By supporting TSO offload capability in software a TAP device can be used
as a failsafe sub device and be paired with another PCI device which
supports TSO capability in HW.

This patch includes 2 commits:
1. Calculation of IP/TCP/UDP checksums for multi segments packets.
Previously checksum offload was skipped if the number of packet segments
was greater than 1.
This commit removes this limitation. It is required before supporting TAP TSO
since the generated TCP TSO may be composed of two segments where the first segment
includes l2,l3,l4 headers.
2. TAP TSO implementation: calling rte_gso_segment() to segment large TCP packets.
This commits creates of a small private mbuf pool in TAP PMD required by librte_gso.
The number of buffers will be 64 - each of 128 bytes length.
TSO segments size refers to TCP payload size (not including l2,l3,l4 headers)
librte_gso supports TCP segmentation above IPv4

The serie was marked as suppressed before 18.05 release in order to include
it in 18.08.

v4 (12 Jun 2018):
Updates following a rebase on top of v18.05

Ophir Munk (2):
  net/tap: calculate checksums of multi segs packets
  net/tap: support TSO (TCP Segment Offload)

 drivers/net/tap/Makefile      |   2 +-
 drivers/net/tap/rte_eth_tap.c | 309 ++++++++++++++++++++++++++++++++----------
 drivers/net/tap/rte_eth_tap.h |   3 +
 mk/rte.app.mk                 |   4 +-
 4 files changed, 244 insertions(+), 74 deletions(-)