Re: [PATCH bpf-next v7 5/5] selftests/bpf: Add ksock test for async callback guard

diff --git a/tools/testing/selftests/bpf/prog_tests/ksock_wq.c b/tools/testing/selftests/bpf/prog_tests/ksock_wq.c
new file mode 100644
index 0000000000000..d6dc20b8f95bb
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/ksock_wq.c

@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2026 Isovalent */
+
+#include <unistd.h>
+
+#include "test_progs.h"
+#include "ksock_wq.skel.h"
+
+#define CALLBACK_WAIT_RETRIES 1000
+#define CALLBACK_WAIT_US 1000
+
+void test_ksock_wq(void)

+{
+	LIBBPF_OPTS(bpf_test_run_opts, opts);
+	struct ksock_wq *skel;
+	u32 callback_done;
+	int err, i;
+
+	skel = ksock_wq__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "ksock_wq open and load"))
+		return;
+
+	err = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.ksock_wq_start),
+				     &opts);
+	if (!ASSERT_OK(err, "run ksock_wq_start"))
+		goto out;
+	if (!ASSERT_OK(opts.retval, "ksock_wq_start retval"))
+		goto out;
+
+	for (i = 0; i < CALLBACK_WAIT_RETRIES; i++) {
+		if (__atomic_load_n(&skel->bss->callback_done, __ATOMIC_ACQUIRE))
+			break;
+		usleep(CALLBACK_WAIT_US);
+	}
+	callback_done = __atomic_load_n(&skel->bss->callback_done,
+					__ATOMIC_ACQUIRE);
+	if (!ASSERT_EQ(callback_done, 1, "workqueue callback completed"))
+		goto out;
+
+	ASSERT_EQ(skel->bss->create_err, -EOPNOTSUPP,
+		  "workqueue create rejected");
+
+out:
+	ksock_wq__destroy(skel);
+}

diff --git a/tools/testing/selftests/bpf/progs/ksock_wq.c b/tools/testing/selftests/bpf/progs/ksock_wq.c
new file mode 100644
index 0000000000000..16a1873d132ed
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/ksock_wq.c

@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2026 Isovalent */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include "bpf_experimental.h"
+#include "bpf_tracing_net.h"
+#include "errno.h"
+#include "ksock_common.h"
+
+struct ksock_wq_value {
+	struct bpf_wq work;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, 1);
+	__type(key, u32);
+	__type(value, struct ksock_wq_value);
+} work_map SEC(".maps");
+
+int create_err;
+u32 callback_done;
+
+static int ksock_wq_callback(void *map, int *key, void *value)
+{
+	struct bpf_ksock_create_opts opts = {
+		.family = AF_INET,
+		.type = SOCK_DGRAM,
+		.protocol = IPPROTO_UDP,
+	};
+	struct bpf_ksock *ks;
+	int err = 0;
+
+	ks = bpf_ksock_create(&opts, sizeof(opts), &err);
+	if (ks)
+		bpf_ksock_release(ks);
+	create_err = err;
+	__sync_fetch_and_add(&callback_done, 1);
+	return 0;
+}