[PATCH bpf-next v2 6/6] selftests/bpf: XSK_TRACE_DROP_FQ_EMPTY test

[Ciara Loftus <ciara.loftus@xxxxxxxxx>]

This test skips the populating of the fill queue which
causes packet drops and traces reporting the drop. The
test validates that these traces were successfully
generated.

Signed-off-by: Ciara Loftus <ciara.loftus@xxxxxxxxx>
---
 tools/testing/selftests/bpf/test_xsk.sh  | 24 ++++++++++++++++++++++++
 tools/testing/selftests/bpf/xdpxceiver.c | 13 +++++++++++--
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_xsk.sh b/tools/testing/selftests/bpf/test_xsk.sh
index 95ceee151de1..997ba0aa79db 100755
--- a/tools/testing/selftests/bpf/test_xsk.sh
+++ b/tools/testing/selftests/bpf/test_xsk.sh
@@ -295,6 +295,30 @@ retval=$?
 test_status $retval "${TEST_NAME}"
 statusList+=($retval)
 
+### TEST 14
+TEST_NAME="SKB TRACE DROP FQ_EMPTY"
+
+vethXDPgeneric ${VETH0} ${VETH1} ${NS1}
+
+params=("-S" "-t" "2" "-C" "${TRACEPKTS}")
+execxdpxceiver params
+
+retval=$?
+test_status $retval "${TEST_NAME}"
+statusList+=($retval)
+
+### TEST 15
+TEST_NAME="DRV TRACE DROP FQ_EMPTY"
+
+vethXDPnative ${VETH0} ${VETH1} ${NS1}
+
+params=("-N" "-t" "2" "-C" "${TRACEPKTS}")
+execxdpxceiver params
+
+retval=$?
+test_status $retval "${TEST_NAME}"
+statusList+=($retval)
+
 ## END TESTS
 
 cleanup_exit ${VETH0} ${VETH1} ${NS1}
diff --git a/tools/testing/selftests/bpf/xdpxceiver.c b/tools/testing/selftests/bpf/xdpxceiver.c
index bee10bb686fc..49c2d42b5882 100644
--- a/tools/testing/selftests/bpf/xdpxceiver.c
+++ b/tools/testing/selftests/bpf/xdpxceiver.c
@@ -37,6 +37,8 @@
  *       Reduce the RXQ size and do not read from it. Validate traces.
  *    f. Tracing - XSK_TRACE_DROP_PKT_TOO_BIG
  *       Increase the headroom size and send packets. Validate traces.
+ *    g. Tracing - XSK_TRACE_DROP_FQ_EMPTY
+ *       Do not populate the fill queue and send packets. Validate traces.
  *
  * 2. AF_XDP DRV/Native mode
  *    Works on any netdevice with XDP_REDIRECT support, driver dependent. Processes
@@ -50,8 +52,9 @@
  *      zero-copy mode
  *    e. Tracing - XSK_TRACE_DROP_RXQ_FULL
  *    f. Tracing - XSK_TRACE_DROP_PKT_TOO_BIG
+ *    g. Tracing - XSK_TRACE_DROP_FQ_EMPTY
  *
- * Total tests: 12
+ * Total tests: 14
  *
  * Flow:
  * -----
@@ -981,7 +984,9 @@ static void *worker_testapp_validate(void *arg)
 			thread_common_ops(ifobject, bufs, &sync_mutex_tx, &spinning_rx);
 
 		ksft_print_msg("Interface [%s] vector [Rx]\n", ifobject->ifname);
-		xsk_populate_fill_ring(ifobject->umem);
+		if (opt_trace_code != XSK_TRACE_DROP_FQ_EMPTY)
+			xsk_populate_fill_ring(ifobject->umem);
+
 
 		TAILQ_INIT(&head);
 		if (debug_pkt_dump) {
@@ -1188,6 +1193,10 @@ int main(int argc, char **argv)
 			expected_traces = opt_pkt_count;
 			reason_str = "packet too big";
 			break;
+		case XSK_TRACE_DROP_FQ_EMPTY:
+			expected_traces = opt_pkt_count;
+			reason_str = "fq empty";
+			break;
 		default:
 			ksft_test_result_fail("ERROR: unsupported trace %i\n",
 						opt_trace_code);
-- 
2.17.1