selftests/xsk: Introduce default Rx pkt stream

In order to prepare xdpxceiver for physical device testing, let us
introduce default Rx pkt stream. Reason for doing it is that physical
device testing will use a UMEM with a doubled size where half of it will
be used by Tx and other half by Rx. This means that pkt addresses will
differ for Tx and Rx streams. Rx thread will initialize the
xsk_umem_info::base_addr that is added here so that pkt_set(), when
working on Rx UMEM will add this offset and second half of UMEM space
will be used. Note that currently base_addr is 0 on both sides. Future
commit will do the mentioned initialization.

Previously, veth based testing worked on separate UMEMs, so single
default stream was fine.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20220901114813.16275-3-maciej.fijalkowski@intel.com

tools/testing/selftests/bpf/xskxceiver.c

@@ -433,15 +433,16 @@ static void __test_spec_init(struct test_spec *test, struct ifobject *ifobj_tx,
 		ifobj->use_poll = false;
 		ifobj->use_fill_ring = true;
 		ifobj->release_rx = true;
-		ifobj->pkt_stream = test->pkt_stream_default;
 		ifobj->validation_func = NULL;
 
 		if (i == 0) {
 			ifobj->rx_on = false;
 			ifobj->tx_on = true;
+			ifobj->pkt_stream = test->tx_pkt_stream_default;
 		} else {
 			ifobj->rx_on = true;
 			ifobj->tx_on = false;
+			ifobj->pkt_stream = test->rx_pkt_stream_default;
 		}
 
 		memset(ifobj->umem, 0, sizeof(*ifobj->umem));
@@ -465,12 +466,15 @@ static void __test_spec_init(struct test_spec *test, struct ifobject *ifobj_tx,
 static void test_spec_init(struct test_spec *test, struct ifobject *ifobj_tx,
 			   struct ifobject *ifobj_rx, enum test_mode mode)
 {
-	struct pkt_stream *pkt_stream;
+	struct pkt_stream *tx_pkt_stream;
+	struct pkt_stream *rx_pkt_stream;
 	u32 i;
 
-	pkt_stream = test->pkt_stream_default;
+	tx_pkt_stream = test->tx_pkt_stream_default;
+	rx_pkt_stream = test->rx_pkt_stream_default;
 	memset(test, 0, sizeof(*test));
-	test->pkt_stream_default = pkt_stream;
+	test->tx_pkt_stream_default = tx_pkt_stream;
+	test->rx_pkt_stream_default = rx_pkt_stream;
 
 	for (i = 0; i < MAX_INTERFACES; i++) {
 		struct ifobject *ifobj = i ? ifobj_rx : ifobj_tx;
@@ -531,16 +535,17 @@ static void pkt_stream_delete(struct pkt_stream *pkt_stream)
 static void pkt_stream_restore_default(struct test_spec *test)
 {
 	struct pkt_stream *tx_pkt_stream = test->ifobj_tx->pkt_stream;
+	struct pkt_stream *rx_pkt_stream = test->ifobj_rx->pkt_stream;
 
-	if (tx_pkt_stream != test->pkt_stream_default) {
+	if (tx_pkt_stream != test->tx_pkt_stream_default) {
 		pkt_stream_delete(test->ifobj_tx->pkt_stream);
-		test->ifobj_tx->pkt_stream = test->pkt_stream_default;
+		test->ifobj_tx->pkt_stream = test->tx_pkt_stream_default;
 	}
 
-	if (test->ifobj_rx->pkt_stream != test->pkt_stream_default &&
-	    test->ifobj_rx->pkt_stream != tx_pkt_stream)
+	if (rx_pkt_stream != test->rx_pkt_stream_default) {
 		pkt_stream_delete(test->ifobj_rx->pkt_stream);
-	test->ifobj_rx->pkt_stream = test->pkt_stream_default;
+		test->ifobj_rx->pkt_stream = test->rx_pkt_stream_default;
+	}
 }
 
 static struct pkt_stream *__pkt_stream_alloc(u32 nb_pkts)
@@ -563,7 +568,7 @@ static struct pkt_stream *__pkt_stream_alloc(u32 nb_pkts)
 
 static void pkt_set(struct xsk_umem_info *umem, struct pkt *pkt, u64 addr, u32 len)
 {
-	pkt->addr = addr;
+	pkt->addr = addr + umem->base_addr;
 	pkt->len = len;
 	if (len > umem->frame_size - XDP_PACKET_HEADROOM - MIN_PKT_SIZE * 2 - umem->frame_headroom)
 		pkt->valid = false;
@@ -602,22 +607,29 @@ static void pkt_stream_replace(struct test_spec *test, u32 nb_pkts, u32 pkt_len)
 
 	pkt_stream = pkt_stream_generate(test->ifobj_tx->umem, nb_pkts, pkt_len);
 	test->ifobj_tx->pkt_stream = pkt_stream;
+	pkt_stream = pkt_stream_generate(test->ifobj_rx->umem, nb_pkts, pkt_len);
 	test->ifobj_rx->pkt_stream = pkt_stream;
 }
 
-static void pkt_stream_replace_half(struct test_spec *test, u32 pkt_len, int offset)
+static void __pkt_stream_replace_half(struct ifobject *ifobj, u32 pkt_len,
+				      int offset)
 {
-	struct xsk_umem_info *umem = test->ifobj_tx->umem;
+	struct xsk_umem_info *umem = ifobj->umem;
 	struct pkt_stream *pkt_stream;
 	u32 i;
 
-	pkt_stream = pkt_stream_clone(umem, test->pkt_stream_default);
-	for (i = 1; i < test->pkt_stream_default->nb_pkts; i += 2)
+	pkt_stream = pkt_stream_clone(umem, ifobj->pkt_stream);
+	for (i = 1; i < ifobj->pkt_stream->nb_pkts; i += 2)
 		pkt_set(umem, &pkt_stream->pkts[i],
 			(i % umem->num_frames) * umem->frame_size + offset, pkt_len);
 
-	test->ifobj_tx->pkt_stream = pkt_stream;
-	test->ifobj_rx->pkt_stream = pkt_stream;
+	ifobj->pkt_stream = pkt_stream;
+}
+
+static void pkt_stream_replace_half(struct test_spec *test, u32 pkt_len, int offset)
+{
+	__pkt_stream_replace_half(test->ifobj_tx, pkt_len, offset);
+	__pkt_stream_replace_half(test->ifobj_rx, pkt_len, offset);
 }
 
 static void pkt_stream_receive_half(struct test_spec *test)
@@ -659,7 +671,8 @@ static struct pkt *pkt_generate(struct ifobject *ifobject, u32 pkt_nb)
 	return pkt;
 }
 
-static void pkt_stream_generate_custom(struct test_spec *test, struct pkt *pkts, u32 nb_pkts)
+static void __pkt_stream_generate_custom(struct ifobject *ifobj,
+					 struct pkt *pkts, u32 nb_pkts)
 {
 	struct pkt_stream *pkt_stream;
 	u32 i;
@@ -668,15 +681,20 @@ static void pkt_stream_generate_custom(struct test_spec *test, struct pkt *pkts,
 	if (!pkt_stream)
 		exit_with_error(ENOMEM);
 
-	test->ifobj_tx->pkt_stream = pkt_stream;
-	test->ifobj_rx->pkt_stream = pkt_stream;
-
 	for (i = 0; i < nb_pkts; i++) {
-		pkt_stream->pkts[i].addr = pkts[i].addr;
+		pkt_stream->pkts[i].addr = pkts[i].addr + ifobj->umem->base_addr;
 		pkt_stream->pkts[i].len = pkts[i].len;
 		pkt_stream->pkts[i].payload = i;
 		pkt_stream->pkts[i].valid = pkts[i].valid;
 	}
+
+	ifobj->pkt_stream = pkt_stream;
+}
+
+static void pkt_stream_generate_custom(struct test_spec *test, struct pkt *pkts, u32 nb_pkts)
+{
+	__pkt_stream_generate_custom(test->ifobj_tx, pkts, nb_pkts);
+	__pkt_stream_generate_custom(test->ifobj_rx, pkts, nb_pkts);
 }
 
 static void pkt_dump(void *pkt, u32 len)
@@ -1745,7 +1763,8 @@ static bool is_xdp_supported(struct ifobject *ifobject)
 
 int main(int argc, char **argv)
 {
-	struct pkt_stream *pkt_stream_default;
+	struct pkt_stream *rx_pkt_stream_default;
+	struct pkt_stream *tx_pkt_stream_default;
 	struct ifobject *ifobj_tx, *ifobj_rx;
 	int modes = TEST_MODE_SKB + 1;
 	u32 i, j, failed_tests = 0;
@@ -1779,10 +1798,12 @@ int main(int argc, char **argv)
 		modes++;
 
 	test_spec_init(&test, ifobj_tx, ifobj_rx, 0);
-	pkt_stream_default = pkt_stream_generate(ifobj_tx->umem, DEFAULT_PKT_CNT, PKT_SIZE);
-	if (!pkt_stream_default)
+	tx_pkt_stream_default = pkt_stream_generate(ifobj_tx->umem, DEFAULT_PKT_CNT, PKT_SIZE);
+	rx_pkt_stream_default = pkt_stream_generate(ifobj_rx->umem, DEFAULT_PKT_CNT, PKT_SIZE);
+	if (!tx_pkt_stream_default || !rx_pkt_stream_default)
 		exit_with_error(ENOMEM);
-	test.pkt_stream_default = pkt_stream_default;
+	test.tx_pkt_stream_default = tx_pkt_stream_default;
+	test.rx_pkt_stream_default = rx_pkt_stream_default;
 
 	ksft_set_plan(modes * TEST_TYPE_MAX);
 
@@ -1796,7 +1817,8 @@ int main(int argc, char **argv)
 				failed_tests++;
 		}
 
-	pkt_stream_delete(pkt_stream_default);
+	pkt_stream_delete(tx_pkt_stream_default);
+	pkt_stream_delete(rx_pkt_stream_default);
 	ifobject_delete(ifobj_tx);
 	ifobject_delete(ifobj_rx);
 

tools/testing/selftests/bpf/xskxceiver.h

@@ -99,6 +99,7 @@ struct xsk_umem_info {
 	u32 frame_headroom;
 	void *buffer;
 	u32 frame_size;
+	u32 base_addr;
 	bool unaligned_mode;
 };
 
@@ -159,7 +160,8 @@ struct ifobject {
 struct test_spec {
 	struct ifobject *ifobj_tx;
 	struct ifobject *ifobj_rx;
-	struct pkt_stream *pkt_stream_default;
+	struct pkt_stream *tx_pkt_stream_default;
+	struct pkt_stream *rx_pkt_stream_default;
 	u16 total_steps;
 	u16 current_step;
 	u16 nb_sockets;