[PATCH net-next v8 8/9] selftests: iou-zcrx: test large chunk sizes

Pavel Begunkov
2026-01-09T11:29:17Z

Add a test using large chunks for zcrx memory area.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
.../selftests/drivers/net/hw/iou-zcrx.c | 72 +++++++++++++++----
.../selftests/drivers/net/hw/iou-zcrx.py | 37 ++++++++++
2 files changed, 97 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
index 62456df947bc..0a19b573f4f5 100644
--- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
+++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.c
@@ -12,6 +12,7 @@
#include <unistd.h>

#include <arpa/inet.h>
+#include <linux/mman.h>
#include <linux/errqueue.h>
#include <linux/if_packet.h>
#include <linux/ipv6.h>
@@ -37,6 +38,23 @@

#include <liburing.h>

+#define SKIP_CODE 42
+
+struct t_io_uring_zcrx_ifq_reg {
+ __u32 if_idx;
+ __u32 if_rxq;
+ __u32 rq_entries;
+ __u32 flags;
+
+ __u64 area_ptr; /* pointer to struct io_uring_zcrx_area_reg */
+ __u64 region_ptr; /* struct io_uring_region_desc * */
+
+ struct io_uring_zcrx_offsets offsets;
+ __u32 zcrx_id;
+ __u32 rx_buf_len;
+ __u64 __resv[3];
+};
+
static long page_size;
#define AREA_SIZE (8192 * page_size)
#define SEND_SIZE (512 * 4096)
@@ -65,6 +83,8 @@ static bool cfg_oneshot;
static int cfg_oneshot_recvs;
static int cfg_send_size = SEND_SIZE;
static struct sockaddr_in6 cfg_addr;
+static unsigned cfg_rx_buf_len;
+static bool cfg_dry_run;

static char *payload;
static void *area_ptr;
@@ -128,14 +148,28 @@ static void setup_zcrx(struct io_uring *ring)
if (!ifindex)
error(1, 0, "bad interface name: %s", cfg_ifname);

- area_ptr = mmap(NULL,
- AREA_SIZE,
- PROT_READ | PROT_WRITE,
- MAP_ANONYMOUS | MAP_PRIVATE,
- 0,
- 0);
- if (area_ptr == MAP_FAILED)
- error(1, 0, "mmap(): zero copy area");
+ if (cfg_rx_buf_len && cfg_rx_buf_len != page_size) {
+ area_ptr = mmap(NULL,
+ AREA_SIZE,
+ PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE |
+ MAP_HUGETLB | MAP_HUGE_2MB,
+ -1,
+ 0);
+ if (area_ptr == MAP_FAILED) {
+ printf("Can't allocate huge pages\n");
+ exit(SKIP_CODE);
+ }
+ } else {
+ area_ptr = mmap(NULL,
+ AREA_SIZE,
+ PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE,
+ 0,
+ 0);
+ if (area_ptr == MAP_FAILED)
+ error(1, 0, "mmap(): zero copy area");
+ }

ring_size = get_refill_ring_size(rq_entries);
ring_ptr = mmap(NULL,
@@ -157,17 +191,23 @@ static void setup_zcrx(struct io_uring *ring)
.flags = 0,
};

- struct io_uring_zcrx_ifq_reg reg = {
+ struct t_io_uring_zcrx_ifq_reg reg = {
.if_idx = ifindex,
.if_rxq = cfg_queue_id,
.rq_entries = rq_entries,
.area_ptr = (__u64)(unsigned long)&area_reg,
.region_ptr = (__u64)(unsigned long)&region_reg,
+ .rx_buf_len = cfg_rx_buf_len,
};

- ret = io_uring_register_ifq(ring, &reg);
- if (ret)
+ ret = io_uring_register_ifq(ring, (void *)&reg);
+ if (cfg_rx_buf_len && (ret == -EINVAL || ret == -EOPNOTSUPP ||
+ ret == -ERANGE)) {
+ printf("Large chunks are not supported %i\n", ret);
+ exit(SKIP_CODE);
+ } else if (ret) {
error(1, 0, "io_uring_register_ifq(): %d", ret);
+ }

rq_ring.khead = (unsigned int *)((char *)ring_ptr + reg.offsets.head);
rq_ring.ktail = (unsigned int *)((char *)ring_ptr + reg.offsets.tail);
@@ -323,6 +363,8 @@ static void run_server(void)
io_uring_queue_init(512, &ring, flags);

setup_zcrx(&ring);
+ if (cfg_dry_run)
+ return;

add_accept(&ring, fd);

@@ -383,7 +425,7 @@ static void parse_opts(int argc, char **argv)
usage(argv[0]);
cfg_payload_len = max_payload_len;

- while ((c = getopt(argc, argv, "sch:p:l:i:q:o:z:")) != -1) {
+ while ((c = getopt(argc, argv, "sch:p:l:i:q:o:z:x:d")) != -1) {
switch (c) {
case 's':
if (cfg_client)
@@ -418,6 +460,12 @@ static void parse_opts(int argc, char **argv)
case 'z':
cfg_send_size = strtoul(optarg, NULL, 0);
break;
+ case 'x':
+ cfg_rx_buf_len = page_size * strtoul(optarg, NULL, 0);
+ break;
+ case 'd':
+ cfg_dry_run = true;
+ break;
}
}

diff --git a/tools/testing/selftests/drivers/net/hw/iou-zcrx.py b/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
index 712c806508b5..83061b27f2f2 100755
--- a/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
+++ b/tools/testing/selftests/drivers/net/hw/iou-zcrx.py
@@ -7,6 +7,7 @@ from lib.py import ksft_run, ksft_exit, KsftSkipEx
from lib.py import NetDrvEpEnv
from lib.py import bkg, cmd, defer, ethtool, rand_port, wait_port_listen

+SKIP_CODE = 42

def _get_current_settings(cfg):
output = ethtool(f"-g {cfg.ifname}", json=True)[0]
@@ -132,6 +133,42 @@ def test_zcrx_rss(cfg) -> None:
cmd(tx_cmd, host=cfg.remote)

+def test_zcrx_large_chunks(cfg) -> None:
+ cfg.require_ipver('6')
+
+ combined_chans = _get_combined_channels(cfg)
+ if combined_chans < 2:
+ raise KsftSkipEx('at least 2 combined channels required')
+ (rx_ring, hds_thresh) = _get_current_settings(cfg)
+ port = rand_port()
+
+ ethtool(f"-G {cfg.ifname} tcp-data-split on")
+ defer(ethtool, f"-G {cfg.ifname} tcp-data-split auto")
+
+ ethtool(f"-G {cfg.ifname} hds-thresh 0")
+ defer(ethtool, f"-G {cfg.ifname} hds-thresh {hds_thresh}")
+
+ ethtool(f"-G {cfg.ifname} rx 64")
+ defer(ethtool, f"-G {cfg.ifname} rx {rx_ring}")
+
+ ethtool(f"-X {cfg.ifname} equal {combined_chans - 1}")
+ defer(ethtool, f"-X {cfg.ifname} default")
+
+ flow_rule_id = _set_flow_rule(cfg, port, combined_chans - 1)
+ defer(ethtool, f"-N {cfg.ifname} delete {flow_rule_id}")
+
+ rx_cmd = f"{cfg.bin_local} -s -p {port} -i {cfg.ifname} -q {combined_chans - 1} -x 2"
+ tx_cmd = f"{cfg.bin_remote} -c -h {cfg.addr_v['6']} -p {port} -l 12840"
+
+ probe = cmd(rx_cmd + " -d", fail=False)
+ if probe.ret == SKIP_CODE:
+ raise KsftSkipEx(probe.stdout)
+
+ with bkg(rx_cmd, exit_wait=True):
+ wait_port_listen(port, proto="tcp")
+ cmd(tx_cmd, host=cfg.remote)
+
+
def main() -> None:
with NetDrvEpEnv(__file__) as cfg:
cfg.bin_local = path.abspath(path.dirname(__file__) + "/../../../drivers/net/hw/iou-zcrx")
--
2.52.0