[PATCH v5 2/3] selftests: net: add flag to force zerocopy mode in xdp_helper

From: Bui Quang Minh
Date: Thu Apr 24 2025 - 06:50:46 EST


This commit adds an optional -z flag to xdp_helper. When this flag is
provided, the XDP socket binding is forced to be in zerocopy mode.

Signed-off-by: Bui Quang Minh <minhquangbui99@xxxxxxxxx>
---
tools/testing/selftests/net/lib/xdp_helper.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/net/lib/xdp_helper.c b/tools/testing/selftests/net/lib/xdp_helper.c
index aeed25914104..f21536ab95ba 100644
--- a/tools/testing/selftests/net/lib/xdp_helper.c
+++ b/tools/testing/selftests/net/lib/xdp_helper.c
@@ -62,6 +62,12 @@ static void ksft_wait(void)
close(fd);
}

+static void print_usage(const char *bin)
+{
+ fprintf(stderr, "Usage: %s ifindex queue_id [-z]\n\n"
+ "where:\n\t-z: force zerocopy mode", bin);
+}
+
/* this is a simple helper program that creates an XDP socket and does the
* minimum necessary to get bind() to succeed.
*
@@ -81,8 +87,8 @@ int main(int argc, char **argv)
int sock_fd;
int queue;

- if (argc != 3) {
- fprintf(stderr, "Usage: %s ifindex queue_id\n", argv[0]);
+ if (argc != 3 && argc != 4) {
+ print_usage(argv[0]);
return 1;
}

@@ -132,6 +138,15 @@ int main(int argc, char **argv)
sxdp.sxdp_queue_id = queue;
sxdp.sxdp_flags = 0;

+ if (argc > 3) {
+ if (!strcmp(argv[3], "-z")) {
+ sxdp.sxdp_flags = XDP_ZEROCOPY;
+ } else {
+ print_usage(argv[0]);
+ return 1;
+ }
+ }
+
if (bind(sock_fd, (struct sockaddr *)&sxdp, sizeof(sxdp)) != 0) {
munmap(umem_area, UMEM_SZ);
perror("bind failed");
--
2.43.0