selftests/xsk: Update poll test cases

Poll test case was not testing all the functionality of the poll feature
in the test suite. This patch updates the poll test case which contains 2
test cases to test the RX and the TX poll functionality and additional 2
more test cases to check the timeout feature of the poll event.

Poll test suite has 4 test cases:

1. TEST_TYPE_RX_POLL: Check if RX path POLLIN function works as expect.
   TX path can use any method to send the traffic.

2. TEST_TYPE_TX_POLL: Check if TX path POLLOUT function works as expect.
   RX path can use any method to receive the traffic.

3. TEST_TYPE_POLL_RXQ_EMPTY: Call poll function with parameter POLLIN on
   empty RX queue will cause timeout. If timeout then test case passes.

4. TEST_TYPE_POLL_TXQ_FULL: When TX queue is filled and packets are not
   cleaned by the kernel then if we invoke the poll function with POLLOUT
   it should trigger timeout.
Signed-off-by: Shibin Koikkara Reeny <shibin.koikkara.reeny@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20220803144354.98122-1-shibin.koikkara.reeny@intel.com

tools/testing/selftests/bpf/xskxceiver.c

@@ -244,6 +244,11 @@ static void gen_udp_hdr(u32 payload, void *pkt, struct ifobject *ifobject,
 	memset32_htonl(pkt + PKT_HDR_SIZE, payload, UDP_PKT_DATA_SIZE);
 }
 
+static bool is_umem_valid(struct ifobject *ifobj)
+{
+	return !!ifobj->umem->umem;
+}
+
 static void gen_udp_csum(struct udphdr *udp_hdr, struct iphdr *ip_hdr)
 {
 	udp_hdr->check = 0;
@@ -817,12 +822,13 @@ static int complete_pkts(struct xsk_socket_info *xsk, int batch_size)
 	return TEST_PASS;
 }
 
-static int receive_pkts(struct ifobject *ifobj, struct pollfd *fds)
+static int receive_pkts(struct test_spec *test, struct pollfd *fds)
 {
-	struct timeval tv_end, tv_now, tv_timeout = {RECV_TMOUT, 0};
+	struct timeval tv_end, tv_now, tv_timeout = {THREAD_TMOUT, 0};
+	struct pkt_stream *pkt_stream = test->ifobj_rx->pkt_stream;
 	u32 idx_rx = 0, idx_fq = 0, rcvd, i, pkts_sent = 0;
-	struct pkt_stream *pkt_stream = ifobj->pkt_stream;
-	struct xsk_socket_info *xsk = ifobj->xsk;
+	struct xsk_socket_info *xsk = test->ifobj_rx->xsk;
+	struct ifobject *ifobj = test->ifobj_rx;
 	struct xsk_umem_info *umem = xsk->umem;
 	struct pkt *pkt;
 	int ret;
@@ -843,17 +849,28 @@ static int receive_pkts(struct ifobject *ifobj, struct pollfd *fds)
 		}
 
 		kick_rx(xsk);
-
-		rcvd = xsk_ring_cons__peek(&xsk->rx, BATCH_SIZE, &idx_rx);
-		if (!rcvd) {
-			if (xsk_ring_prod__needs_wakeup(&umem->fq)) {
+		if (ifobj->use_poll) {
 			ret = poll(fds, 1, POLL_TMOUT);
 			if (ret < 0)
 				exit_with_error(-ret);
+
+			if (!ret) {
+				if (!is_umem_valid(test->ifobj_tx))
+					return TEST_PASS;
+
+				ksft_print_msg("ERROR: [%s] Poll timed out\n", __func__);
+				return TEST_FAILURE;
+
 			}
+
+			if (!(fds->revents & POLLIN))
 				continue;
 		}
 
+		rcvd = xsk_ring_cons__peek(&xsk->rx, BATCH_SIZE, &idx_rx);
+		if (!rcvd)
+			continue;
+
 		if (ifobj->use_fill_ring) {
 			ret = xsk_ring_prod__reserve(&umem->fq, rcvd, &idx_fq);
 			while (ret != rcvd) {
@@ -900,13 +917,35 @@ static int receive_pkts(struct ifobject *ifobj, struct pollfd *fds)
 	return TEST_PASS;
 }
 
-static int __send_pkts(struct ifobject *ifobject, u32 *pkt_nb)
+static int __send_pkts(struct ifobject *ifobject, u32 *pkt_nb, struct pollfd *fds,
+		       bool timeout)
 {
 	struct xsk_socket_info *xsk = ifobject->xsk;
-	u32 i, idx, valid_pkts = 0;
+	bool use_poll = ifobject->use_poll;
+	u32 i, idx, ret, valid_pkts = 0;
+
+	while (xsk_ring_prod__reserve(&xsk->tx, BATCH_SIZE, &idx) < BATCH_SIZE) {
+		if (use_poll) {
+			ret = poll(fds, 1, POLL_TMOUT);
+			if (timeout) {
+				if (ret < 0) {
+					ksft_print_msg("ERROR: [%s] Poll error %d\n",
+						       __func__, ret);
+					return TEST_FAILURE;
+				}
+				if (ret == 0)
+					return TEST_PASS;
+				break;
+			}
+			if (ret <= 0) {
+				ksft_print_msg("ERROR: [%s] Poll error %d\n",
+					       __func__, ret);
+				return TEST_FAILURE;
+			}
+		}
 
-	while (xsk_ring_prod__reserve(&xsk->tx, BATCH_SIZE, &idx) < BATCH_SIZE)
 		complete_pkts(xsk, BATCH_SIZE);
+	}
 
 	for (i = 0; i < BATCH_SIZE; i++) {
 		struct xdp_desc *tx_desc = xsk_ring_prod__tx_desc(&xsk->tx, idx + i);
@@ -933,11 +972,27 @@ static int __send_pkts(struct ifobject *ifobject, u32 *pkt_nb)
 
 	xsk_ring_prod__submit(&xsk->tx, i);
 	xsk->outstanding_tx += valid_pkts;
+
+	if (use_poll) {
+		ret = poll(fds, 1, POLL_TMOUT);
+		if (ret <= 0) {
+			if (ret == 0 && timeout)
+				return TEST_PASS;
+
+			ksft_print_msg("ERROR: [%s] Poll error %d\n", __func__, ret);
+			return TEST_FAILURE;
+		}
+	}
+
+	if (!timeout) {
 		if (complete_pkts(xsk, i))
 			return TEST_FAILURE;
 
 		usleep(10);
 		return TEST_PASS;
+	}
+
+	return TEST_CONTINUE;
 }
 
 static void wait_for_tx_completion(struct xsk_socket_info *xsk)
@@ -948,29 +1003,19 @@ static void wait_for_tx_completion(struct xsk_socket_info *xsk)
 
 static int send_pkts(struct test_spec *test, struct ifobject *ifobject)
 {
+	bool timeout = !is_umem_valid(test->ifobj_rx);
 	struct pollfd fds = { };
-	u32 pkt_cnt = 0;
+	u32 pkt_cnt = 0, ret;
 
 	fds.fd = xsk_socket__fd(ifobject->xsk->xsk);
 	fds.events = POLLOUT;
 
 	while (pkt_cnt < ifobject->pkt_stream->nb_pkts) {
-		int err;
-
-		if (ifobject->use_poll) {
-			int ret;
-
-			ret = poll(&fds, 1, POLL_TMOUT);
-			if (ret <= 0)
-				continue;
-
-			if (!(fds.revents & POLLOUT))
-				continue;
-		}
-
-		err = __send_pkts(ifobject, &pkt_cnt);
-		if (err || test->fail)
+		ret = __send_pkts(ifobject, &pkt_cnt, &fds, timeout);
+		if ((ret || test->fail) && !timeout)
 			return TEST_FAILURE;
+		else if (ret == TEST_PASS && timeout)
+			return ret;
 	}
 
 	wait_for_tx_completion(ifobject->xsk);
@@ -1235,7 +1280,7 @@ static void *worker_testapp_validate_rx(void *arg)
 
 	pthread_barrier_wait(&barr);
 
-	err = receive_pkts(ifobject, &fds);
+	err = receive_pkts(test, &fds);
 
 	if (!err && ifobject->validation_func)
 		err = ifobject->validation_func(ifobject);
@@ -1251,6 +1296,33 @@ static void *worker_testapp_validate_rx(void *arg)
 	pthread_exit(NULL);
 }
 
+static int testapp_validate_traffic_single_thread(struct test_spec *test, struct ifobject *ifobj,
+						  enum test_type type)
+{
+	pthread_t t0;
+
+	if (pthread_barrier_init(&barr, NULL, 2))
+		exit_with_error(errno);
+
+	test->current_step++;
+	if (type  == TEST_TYPE_POLL_RXQ_TMOUT)
+		pkt_stream_reset(ifobj->pkt_stream);
+	pkts_in_flight = 0;
+
+	/*Spawn thread */
+	pthread_create(&t0, NULL, ifobj->func_ptr, test);
+
+	if (type != TEST_TYPE_POLL_TXQ_TMOUT)
+		pthread_barrier_wait(&barr);
+
+	if (pthread_barrier_destroy(&barr))
+		exit_with_error(errno);
+
+	pthread_join(t0, NULL);
+
+	return !!test->fail;
+}
+
 static int testapp_validate_traffic(struct test_spec *test)
 {
 	struct ifobject *ifobj_tx = test->ifobj_tx;
@@ -1548,12 +1620,30 @@ static void run_pkt_test(struct test_spec *test, enum test_mode mode, enum test_
 
 		pkt_stream_restore_default(test);
 		break;
-	case TEST_TYPE_POLL:
-		test->ifobj_tx->use_poll = true;
+	case TEST_TYPE_RX_POLL:
 		test->ifobj_rx->use_poll = true;
-		test_spec_set_name(test, "POLL");
+		test_spec_set_name(test, "POLL_RX");
 		testapp_validate_traffic(test);
 		break;
+	case TEST_TYPE_TX_POLL:
+		test->ifobj_tx->use_poll = true;
+		test_spec_set_name(test, "POLL_TX");
+		testapp_validate_traffic(test);
+		break;
+	case TEST_TYPE_POLL_TXQ_TMOUT:
+		test_spec_set_name(test, "POLL_TXQ_FULL");
+		test->ifobj_tx->use_poll = true;
+		/* create invalid frame by set umem frame_size and pkt length equal to 2048 */
+		test->ifobj_tx->umem->frame_size = 2048;
+		pkt_stream_replace(test, 2 * DEFAULT_PKT_CNT, 2048);
+		testapp_validate_traffic_single_thread(test, test->ifobj_tx, type);
+		pkt_stream_restore_default(test);
+		break;
+	case TEST_TYPE_POLL_RXQ_TMOUT:
+		test_spec_set_name(test, "POLL_RXQ_EMPTY");
+		test->ifobj_rx->use_poll = true;
+		testapp_validate_traffic_single_thread(test, test->ifobj_rx, type);
+		break;
 	case TEST_TYPE_ALIGNED_INV_DESC:
 		test_spec_set_name(test, "ALIGNED_INV_DESC");
 		testapp_invalid_desc(test);

tools/testing/selftests/bpf/xskxceiver.h

@@ -27,6 +27,7 @@
 
 #define TEST_PASS 0
 #define TEST_FAILURE -1
+#define TEST_CONTINUE 1
 #define MAX_INTERFACES 2
 #define MAX_INTERFACE_NAME_CHARS 7
 #define MAX_INTERFACES_NAMESPACE_CHARS 10
@@ -48,7 +49,7 @@
 #define SOCK_RECONF_CTR 10
 #define BATCH_SIZE 64
 #define POLL_TMOUT 1000
-#define RECV_TMOUT 3
+#define THREAD_TMOUT 3
 #define DEFAULT_PKT_CNT (4 * 1024)
 #define DEFAULT_UMEM_BUFFERS (DEFAULT_PKT_CNT / 4)
 #define UMEM_SIZE (DEFAULT_UMEM_BUFFERS * XSK_UMEM__DEFAULT_FRAME_SIZE)
@@ -68,7 +69,10 @@ enum test_type {
 	TEST_TYPE_RUN_TO_COMPLETION,
 	TEST_TYPE_RUN_TO_COMPLETION_2K_FRAME,
 	TEST_TYPE_RUN_TO_COMPLETION_SINGLE_PKT,
-	TEST_TYPE_POLL,
+	TEST_TYPE_RX_POLL,
+	TEST_TYPE_TX_POLL,
+	TEST_TYPE_POLL_RXQ_TMOUT,
+	TEST_TYPE_POLL_TXQ_TMOUT,
 	TEST_TYPE_UNALIGNED,
 	TEST_TYPE_ALIGNED_INV_DESC,
 	TEST_TYPE_ALIGNED_INV_DESC_2K_FRAME,