[PATCH net-next v2 2/2] io_uring/zcrx: selftests: verify rx_buf_len for large chunks

[Dragos Tatulea <dtatulea@nvidia.com>]

Check the newly added rx_buf_len page_pool field for io_uring
in the existing large-chunks test after the receiver is up.

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
---
 .../selftests/drivers/net/hw/iou-zcrx.py      | 26 ++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.py b/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
index d72b76ba0835..b7a225fe4bea 100755
--- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
+++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
 import re
+import resource
 import time
 from os import path
 from lib.py import ksft_run, ksft_exit, KsftSkipEx, ksft_variants, KsftNamedVariant
@@ -41,6 +42,23 @@ def set_flow_rule_rss(cfg, rss_ctx_id):
     return int(values)
 
 
+def check_iou_rx_buf_len(cfg, expected_rx_buf_len):
+    """Check the io-uring memory provider exposes the expected rx_buf_len."""
+    q = cfg.netnl.queue_get({'ifindex': cfg.ifindex, 'type': 'rx', 'id': cfg.target})
+    napi_id = q['napi-id']
+    pools = cfg.netnl.page_pool_get({}, dump=True)
+    pools = [p for p in pools if p.get('napi-id') == napi_id
+             and 'io-uring' in p]
+    if len(pools) != 1:
+        raise Exception(f"Expected 1 io-uring page pool, found {len(pools)}")
+    rx_buf_len = pools[0]['io-uring'].get('rx-buf-len')
+    if rx_buf_len is None:
+        raise KsftSkipEx("io-uring 'rx-buf-len' attribute not supported")
+    if rx_buf_len != expected_rx_buf_len:
+        raise Exception(f'Expected io-uring rx-buf-len {expected_rx_buf_len}, '
+                        f'got {rx_buf_len}')
+
+
 def single(cfg):
     channels = cfg.ethnl.channels_get({'header': {'dev-index': cfg.ifindex}})
     channels = channels['combined-count']
@@ -156,7 +174,10 @@ def test_zcrx_large_chunks(cfg) -> None:
             defer(lambda: open(hp_file, 'w', encoding='utf-8').write(str(nr_hugepages)))
 
     single(cfg)
-    rx_cmd = f"{cfg.bin_local} -s -p {cfg.port} -i {cfg.ifname} -q {cfg.target} -x 2"
+    page_size = resource.getpagesize()
+    nr_pages = 2
+    rx_buf_len = nr_pages * page_size
+    rx_cmd = f"{cfg.bin_local} -s -p {cfg.port} -i {cfg.ifname} -q {cfg.target} -x {nr_pages}"
     tx_cmd = f"{cfg.bin_remote} -c -h {cfg.addr_v['6']} -p {cfg.port} -l 12840"
 
     probe = cmd(rx_cmd + " -d", fail=False)
@@ -166,6 +187,9 @@ def test_zcrx_large_chunks(cfg) -> None:
     mp_clear_wait(cfg)
     with bkg(rx_cmd, exit_wait=True):
         wait_port_listen(cfg.port, proto="tcp")
+
+        check_iou_rx_buf_len(cfg, rx_buf_len)
+
         cmd(tx_cmd, host=cfg.remote)
 
 
-- 
2.54.0