[PATCH net-next v3 0/4] gve: Improve RX buffer length management

[joshwash@google.com]

From: Ankit Garg <nktgrg@google.com>

This patch series improves the management of the RX buffer length for
the DQO queue format in the gve driver. The goal is to make RX buffer
length config more explicit, easy to change, and performant by default.

We accomplish that in four patches:

1.  Currently, the buffer length is implicitly coupled with the header
    split setting, which is an unintuitive and restrictive design. The
    first patch decouples the RX buffer length from the header split
    configuration.

2.  The second patch is a preparatory step for third. It converts the XDP
    config verification method to use extack for better error reporting.

3.  The third patch exposes the `rx_buf_len` parameter to userspace via
    ethtool, allowing user to directly view or modify the RX buffer length
    if supported by the device.

4.  The final patch improves the out-of-the-box RX single stream throughput
    by >10%  by changing the driver's default behavior to select the
    maximum supported RX buffer length advertised by the device during
    initialization.

Changes in v3:
* Removed newline from extack message (Jakub Kicinski)

Changes in v2:
* Plumbed extack during xdp verification in patch 2 (Jakub Kicinski)
* Refactored RX buffer length validation to clarify that it handles
  scenario when device doesn't advertise 4K support (Jakub Kicinski)

Ankit Garg (4):
  gve: Decouple header split from RX buffer length
  gve: Use extack to log xdp config verification errors
  gve: Allow ethtool to configure rx_buf_len
  gve: Default to max_rx_buffer_size for DQO if device supported

 drivers/net/ethernet/google/gve/gve.h         | 12 +++++--
 drivers/net/ethernet/google/gve/gve_adminq.c  |  4 +++
 drivers/net/ethernet/google/gve/gve_ethtool.c | 13 +++++--
 drivers/net/ethernet/google/gve/gve_main.c    | 73 +++++++++++++++++++++++++++++-----------
 4 files changed, 78 insertions(+), 24 deletions(-)

-- 
2.51.2.997.g839fc31de9-goog