[PATCH v4 00/10] net/gve: fix DQO Tx queue stalls

[Tathagat Priyadarshi <tathagat.dpdk@gmail.com>]

This series fixes several ways the gve DQO RDA Tx path can stall or
post invalid descriptors: completion handling bugs (1-2), a report
event interval that can starve the ring (3), a stray TSO context
descriptor when completion tags run out (4), a missing cacheline
margin (5), invalid packets blocking the burst (6-8), and missing
device length checks (9-10).

v4:
- Rebased on main; v3 no longer applied after 4a543ae8c8
  ("net/gve: clean Tx queue directly in DQO") removed txqs next
  to the field changed in 3/10. No functional changes.

v3:
- Split the series into one fix per patch, per review feedback.
  The code is the same as v2 except where noted below.
- 1/10, 2/10: v2 1/4, split in two. Kept Joshua's Ack.
- 3/10: v2 2/4 without the declaration reordering
  (per Joshua Washington) and without ringing the doorbell on each
  report event, which is a performance change to be sent separately
  with numbers (per Stephen Hemminger).
- 4/10: the completion tag reorder from v2 2/4, as its own patch.
  Fixes tag now points at the commit that made the tag pop fallible.
- 5/10: v2 3/4, unchanged. Kept Joshua's Ack.
- 6/10-10/10: v2 4/4, split:
  * Keep too_many_descs and add per-reason invalid_mbufs and
    invalid_pkts counters instead of a generic dropped_pkts
    (per Joshua Washington), and export them as xstats
    (per Stephen Hemminger).
  * Count sent packets after writing descriptors instead of
    subtracting drops (per Joshua Washington).
  * Move the length and TSO header checks into gve_tx_validate_pkt(),
    leaving gve_tx_validate_descs() to descriptor counts, without
    the declaration moves.
  * Reword the TSO length limit (per Stephen Hemminger) and shorten
    the commit messages.
- Stephen's Reviewed-by on v2 is not carried over because of the
  rework.

Tathagat Priyadarshi (10):
  net/gve: fix DQO descriptor cleaning loop bound
  net/gve: fix DQO completion queue stall on unknown type
  net/gve: fix DQO Tx report event interval
  net/gve: fix stray TSO context descriptor on tag exhaustion
  net/gve: add cacheline overlap margin to DQO Tx ring
  net/gve: fix Tx stall on invalid packets
  net/gve: export Tx drop counters in xstats
  net/gve: reject Tx packets that cannot fit in the ring
  net/gve: enforce DQO Tx packet length limits
  net/gve: enforce DQO TSO header and length limits

 drivers/net/gve/base/gve_desc_dqo.h |   3 +
 drivers/net/gve/gve_ethdev.c        |   3 +
 drivers/net/gve/gve_ethdev.h        |   4 +-
 drivers/net/gve/gve_tx_dqo.c        | 113 +++++++++++++++++++++-------
 4 files changed, 96 insertions(+), 27 deletions(-)

-- 
2.43.0