[PATCH v2 0/4] net/gve: TSO descriptor count fixes for GVE DQO

[Joshua Washington <joshwash@google.com>]

https://inbox.dpdk.org/dev/20250707231812.1937260-7-joshwash@google.com/
introduced descriptor limit checks for TSO packets in DPDK.
Unfortunately, a couple of bugs have been found in the implementation.

This patch series introduces fixes for those bugs while correcting the
overly restrictive behavior recently introduced mandating that all
headers be in the same buffer.

The final patch in the series introduces tx_pkt_prepare as an option to
ensure that there is a way to get a clear signal of when packets violate
hardware limitations. Before a recently introduced patch, the GVE
behavior was to stop transmitting at the first invalid packet, which
would allow the application to do any necessary linearization or packet
modification before attempting to transmit again. It turns out that that
behavior is considered incorrect, so offer tx_pkt_prepare as an
alternative.

Depends-on: series-39707 ("net/gve: fix DQO Tx queue stalls")

Changes in v2:
- Rely on tx_pkt->nb_segs for descriptor limit calculation only as a
  precursor, falling back to the traditional gve_tx_pkt_nb_data_descs()
  if that optimization fails.
- Only call rte_net_intel_cksum_preapre on TSO packets that request
  checksum offloading. This enforces the additional requirement that
  headers are all in the same mbuf segment.
- Introduce new patch to validate minimum header length.

Joshua Washington (4):
  net/gve: fix TSO segment offset calculation
  net/gve: account for multi-mbuf headers when validating TSO
  net/gve: introduce Tx packet preparation for DQO format
  net/gve: validate minimum header length for TSO packets

 drivers/net/gve/base/gve_desc_dqo.h |   2 +
 drivers/net/gve/gve_ethdev.h        |   3 +
 drivers/net/gve/gve_tx_dqo.c        | 121 +++++++++++++++++++++++++---
 3 files changed, 113 insertions(+), 13 deletions(-)

-- 
2.56.0.317.g454f8302e1-goog