[PATCH net-next v4 0/6] selftests: drv-net: driver tests for HW GRO

[PATCH net-next v4 0/6] selftests: drv-net: driver tests for HW GRO

[Jakub Kicinski]

Add tests for HW GRO stats, packet ordering and depth.

The ynltool and bnxt patches from v2 were applied separately.

v4:
 - [patch 6] rename [FAIL] -> [MISS]; NIPA thinks every [FAIL]
   means test failed, 'cause bash test don't ktap :/
v3: https://lore.kernel.org/20260316224505.279672-1-kuba@kernel.org
 - [patch 3] add a note about fq being needed
v2: https://lore.kernel.org/20260207003509.3927744-1-kuba@kernel.org
 - [patch 3] do not enable SO_TXTIME for multi-flow tests
 - [patch 6] move the test to cover SW GRO
v1: https://lore.kernel.org/20260205220541.2992807-1-kuba@kernel.org

Jakub Kicinski (6):
  selftests: net: move gro to lib for HW vs SW reuse
  selftests: drv-net: give HW stats sync time extra 25% of margin
  selftests: drv-net: gro: use SO_TXTIME to schedule packets together
  selftests: drv-net: gro: test GRO stats
  selftests: drv-net: gro: add test for packet ordering
  selftests: drv-net: gro: add a test for GRO depth

 tools/testing/selftests/drivers/net/Makefile  |   1 -
 .../testing/selftests/drivers/net/hw/Makefile |   1 +
 tools/testing/selftests/net/lib/Makefile      |   1 +
 .../selftests/{drivers/net => net/lib}/gro.c  | 252 ++++++++++++++-
 .../testing/selftests/drivers/net/.gitignore  |   1 -
 tools/testing/selftests/drivers/net/gro.py    | 203 ++++++++++--
 .../selftests/drivers/net/hw/gro_hw.py        | 294 ++++++++++++++++++
 .../selftests/drivers/net/lib/py/env.py       |   4 +-
 tools/testing/selftests/net/lib/.gitignore    |   1 +
 9 files changed, 728 insertions(+), 30 deletions(-)
 rename tools/testing/selftests/{drivers/net => net/lib}/gro.c (86%)
 create mode 100755 tools/testing/selftests/drivers/net/hw/gro_hw.py

-- 
2.53.0

[PATCH net-next v4 1/6] selftests: net: move gro to lib for HW vs SW reuse

[Jakub Kicinski]

The gro.c packet sender is used for SW testing but bulk of incoming
new tests will be HW-specific. So it's better to put them under
drivers/net/hw/, to avoid tip-toeing around netdevsim. Move gro.c
to lib so we can reuse it.

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 tools/testing/selftests/drivers/net/Makefile           | 1 -
 tools/testing/selftests/net/lib/Makefile               | 1 +
 tools/testing/selftests/{drivers/net => net/lib}/gro.c | 2 +-
 tools/testing/selftests/drivers/net/.gitignore         | 1 -
 tools/testing/selftests/drivers/net/gro.py             | 2 +-
 tools/testing/selftests/net/lib/.gitignore             | 1 +
 6 files changed, 4 insertions(+), 4 deletions(-)
 rename tools/testing/selftests/{drivers/net => net/lib}/gro.c (99%)

diff --git a/tools/testing/selftests/drivers/net/Makefile b/tools/testing/selftests/drivers/net/Makefile
index 8154d6d429d3..7c7fa75b80c2 100644
--- a/tools/testing/selftests/drivers/net/Makefile
+++ b/tools/testing/selftests/drivers/net/Makefile
@@ -6,7 +6,6 @@ TEST_INCLUDES := $(wildcard lib/py/*.py) \
 		 ../../net/lib.sh \
 
 TEST_GEN_FILES := \
-	gro \
 	napi_id_helper \
 # end of TEST_GEN_FILES
 
diff --git a/tools/testing/selftests/net/lib/Makefile b/tools/testing/selftests/net/lib/Makefile
index 5339f56329e1..ff83603397d0 100644
--- a/tools/testing/selftests/net/lib/Makefile
+++ b/tools/testing/selftests/net/lib/Makefile
@@ -14,6 +14,7 @@ TEST_FILES := \
 TEST_GEN_FILES := \
 	$(patsubst %.c,%.o,$(wildcard *.bpf.c)) \
 	csum \
+	gro \
 	xdp_helper \
 # end of TEST_GEN_FILES
 
diff --git a/tools/testing/selftests/drivers/net/gro.c b/tools/testing/selftests/net/lib/gro.c
similarity index 99%
rename from tools/testing/selftests/drivers/net/gro.c
rename to tools/testing/selftests/net/lib/gro.c
index 3c0745b68bfa..02e29509fbea 100644
--- a/tools/testing/selftests/drivers/net/gro.c
+++ b/tools/testing/selftests/net/lib/gro.c
@@ -77,7 +77,7 @@
 #include <unistd.h>
 
 #include "kselftest.h"
-#include "../../net/lib/ksft.h"
+#include "ksft.h"
 
 #define DPORT 8000
 #define SPORT 1500
diff --git a/tools/testing/selftests/drivers/net/.gitignore b/tools/testing/selftests/drivers/net/.gitignore
index 3633c7a3ed65..585ecb4d5dc4 100644
--- a/tools/testing/selftests/drivers/net/.gitignore
+++ b/tools/testing/selftests/drivers/net/.gitignore
@@ -1,4 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
-gro
 napi_id_helper
 psp_responder
diff --git a/tools/testing/selftests/drivers/net/gro.py b/tools/testing/selftests/drivers/net/gro.py
index cbc1b19dbc91..2da53686354f 100755
--- a/tools/testing/selftests/drivers/net/gro.py
+++ b/tools/testing/selftests/drivers/net/gro.py
@@ -117,7 +117,7 @@ from lib.py import ksft_variants
     """ Setup hardware loopback mode for GRO testing. """
 
     if not hasattr(cfg, "bin_remote"):
-        cfg.bin_local = cfg.test_dir / "gro"
+        cfg.bin_local = cfg.net_lib_dir / "gro"
         cfg.bin_remote = cfg.remote.deploy(cfg.bin_local)
 
     if not hasattr(cfg, "feat"):
diff --git a/tools/testing/selftests/net/lib/.gitignore b/tools/testing/selftests/net/lib/.gitignore
index bbc97d6bf556..6cd2b762af5d 100644
--- a/tools/testing/selftests/net/lib/.gitignore
+++ b/tools/testing/selftests/net/lib/.gitignore
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
 csum
+gro
 xdp_helper
-- 
2.53.0

[PATCH net-next v4 2/6] selftests: drv-net: give HW stats sync time extra 25% of margin

[Jakub Kicinski]

There are transient failures for devices which update stats
periodically, especially if it's the FW DMA'ing the stats
rather than host periodic work querying the FW. Wait 25%
longer than strictly necessary.

For devices which don't report stats-block-usecs we retain
25 msec as the default wait time (0.025sec == 20,000usec * 1.25).

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 tools/testing/selftests/drivers/net/lib/py/env.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/lib/py/env.py b/tools/testing/selftests/drivers/net/lib/py/env.py
index ccff345fe1c1..6a71c7e7f136 100644
--- a/tools/testing/selftests/drivers/net/lib/py/env.py
+++ b/tools/testing/selftests/drivers/net/lib/py/env.py
@@ -288,8 +288,8 @@ from . import bpftool, RtnlFamily, Netlink
                 if "Operation not supported" not in e.cmd.stderr:
                     raise
 
-            self._stats_settle_time = 0.025 + \
-                data.get('stats-block-usecs', 0) / 1000 / 1000
+            self._stats_settle_time = \
+                1.25 * data.get('stats-block-usecs', 20000) / 1000 / 1000
 
         time.sleep(self._stats_settle_time)
 
-- 
2.53.0

[PATCH net-next v4 3/6] selftests: drv-net: gro: use SO_TXTIME to schedule packets together

[Jakub Kicinski]

Longer packet sequence tests are quite flaky when the test is run
over a real network. Try to avoid at least the jitter on the sender
side by scheduling all the packets to be sent at once using SO_TXTIME.
Use hardcoded tx time of 5msec in the future. In my test increasing
this time past 2msec makes no difference so 5msec is plenty of margin.
Since we now expect more output buffering make sure to raise SNDBUF.

Note that this is an opportunistic reliability improvement which
will only work if the qdisc can schedule Tx time for us (fq).
Fiddling with qdisc config was deemed too complex, so it's not
part of the patch.

Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
v3:
 - update the commit msg
v2: https://lore.kernel.org/20260207003509.3927744-7-kuba@kernel.org
 - only enable TXTIME when we are sending a single flow
v1: https://lore.kernel.org/20260205220541.2992807-7-kuba@kernel.org
---
 tools/testing/selftests/net/lib/gro.c | 57 +++++++++++++++++++++++++--
 1 file changed, 54 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/net/lib/gro.c b/tools/testing/selftests/net/lib/gro.c
index 02e29509fbea..5b3f8fca08e6 100644
--- a/tools/testing/selftests/net/lib/gro.c
+++ b/tools/testing/selftests/net/lib/gro.c
@@ -63,6 +63,7 @@
 #include <linux/filter.h>
 #include <linux/if_packet.h>
 #include <linux/ipv6.h>
+#include <linux/net_tstamp.h>
 #include <net/ethernet.h>
 #include <net/if.h>
 #include <netinet/in.h>
@@ -74,6 +75,7 @@
 #include <stdio.h>
 #include <stdarg.h>
 #include <string.h>
+#include <time.h>
 #include <unistd.h>
 
 #include "kselftest.h"
@@ -123,6 +125,9 @@ static int tcp_offset = -1;
 static int total_hdr_len = -1;
 static int ethhdr_proto = -1;
 static bool ipip;
+static uint64_t txtime_ns;
+
+#define TXTIME_DELAY_MS 5
 
 static void vlog(const char *fmt, ...)
 {
@@ -330,13 +335,37 @@ static void fill_transportlayer(void *buf, int seq_offset, int ack_offset,
 
 static void write_packet(int fd, char *buf, int len, struct sockaddr_ll *daddr)
 {
+	char control[CMSG_SPACE(sizeof(uint64_t))];
+	struct msghdr msg = {};
+	struct iovec iov = {};
+	struct cmsghdr *cm;
 	int ret = -1;
 
-	ret = sendto(fd, buf, len, 0, (struct sockaddr *)daddr, sizeof(*daddr));
+	iov.iov_base = buf;
+	iov.iov_len = len;
+
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_name = daddr;
+	msg.msg_namelen = sizeof(*daddr);
+
+	if (txtime_ns) {
+		memset(control, 0, sizeof(control));
+		msg.msg_control = control;
+		msg.msg_controllen = sizeof(control);
+
+		cm = CMSG_FIRSTHDR(&msg);
+		cm->cmsg_level = SOL_SOCKET;
+		cm->cmsg_type = SCM_TXTIME;
+		cm->cmsg_len = CMSG_LEN(sizeof(uint64_t));
+		memcpy(CMSG_DATA(cm), &txtime_ns, sizeof(txtime_ns));
+	}
+
+	ret = sendmsg(fd, &msg, 0);
 	if (ret == -1)
-		error(1, errno, "sendto failure");
+		error(1, errno, "sendmsg failure");
 	if (ret != len)
-		error(1, errno, "sendto wrong length");
+		error(1, 0, "sendmsg wrong length: %d vs %d", ret, len);
 }
 
 static void create_packet(void *buf, int seq_offset, int ack_offset,
@@ -1058,6 +1087,7 @@ static void check_recv_pkts(int fd, int *correct_payload,
 
 static void gro_sender(void)
 {
+	int bufsize = 4 * 1024 * 1024; /* 4 MB */
 	const int fin_delay_us = 100 * 1000;
 	static char fin_pkt[MAX_HDR_LEN];
 	struct sockaddr_ll daddr = {};
@@ -1067,6 +1097,27 @@ static void gro_sender(void)
 	if (txfd < 0)
 		error(1, errno, "socket creation");
 
+	if (setsockopt(txfd, SOL_SOCKET, SO_SNDBUF, &bufsize, sizeof(bufsize)))
+		error(1, errno, "cannot set sndbuf size, setsockopt failed");
+
+	/* Enable SO_TXTIME unless test case generates more than one flow
+	 * SO_TXTIME could result in qdisc layer sorting the packets at sender.
+	 */
+	if (true) {
+		struct sock_txtime so_txtime = { .clockid = CLOCK_MONOTONIC, };
+		struct timespec ts;
+
+		if (setsockopt(txfd, SOL_SOCKET, SO_TXTIME,
+			       &so_txtime, sizeof(so_txtime)))
+			error(1, errno, "setsockopt SO_TXTIME");
+
+		if (clock_gettime(CLOCK_MONOTONIC, &ts))
+			error(1, errno, "clock_gettime");
+
+		txtime_ns = ts.tv_sec * 1000000000ULL + ts.tv_nsec;
+		txtime_ns += TXTIME_DELAY_MS * 1000000ULL;
+	}
+
 	memset(&daddr, 0, sizeof(daddr));
 	daddr.sll_ifindex = if_nametoindex(ifname);
 	if (daddr.sll_ifindex == 0)
-- 
2.53.0

[PATCH net-next v4 4/6] selftests: drv-net: gro: test GRO stats

[Jakub Kicinski]

Test accuracy of GRO stats. We want to cover two potentially tricky
cases:
 - single segment GRO
 - packets which were eligible but didn't get GRO'd

The first case is trivial, teach gro.c to send one packet, and check
GRO stats didn't move.

Second case requires gro.c to send a lot of flows expecting the NIC
to run out of GRO flow capacity.

To avoid system traffic noise we steer the packets to a dedicated
queue and operate on qstat.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 .../testing/selftests/drivers/net/hw/Makefile |   1 +
 tools/testing/selftests/net/lib/gro.c         | 163 ++++++++++-
 .../selftests/drivers/net/hw/gro_hw.py        | 271 ++++++++++++++++++
 3 files changed, 433 insertions(+), 2 deletions(-)
 create mode 100755 tools/testing/selftests/drivers/net/hw/gro_hw.py

diff --git a/tools/testing/selftests/drivers/net/hw/Makefile b/tools/testing/selftests/drivers/net/hw/Makefile
index 91df028abfc0..3c97dac9baaa 100644
--- a/tools/testing/selftests/drivers/net/hw/Makefile
+++ b/tools/testing/selftests/drivers/net/hw/Makefile
@@ -26,6 +26,7 @@ TEST_PROGS = \
 	ethtool_extended_state.sh \
 	ethtool_mm.sh \
 	ethtool_rmon.sh \
+	gro_hw.py \
 	hw_stats_l3.sh \
 	hw_stats_l3_gre.sh \
 	iou-zcrx.py \
diff --git a/tools/testing/selftests/net/lib/gro.c b/tools/testing/selftests/net/lib/gro.c
index 5b3f8fca08e6..41794b9f6f8a 100644
--- a/tools/testing/selftests/net/lib/gro.c
+++ b/tools/testing/selftests/net/lib/gro.c
@@ -43,6 +43,10 @@
  *   - large_max: exceeding max size
  *   - large_rem: remainder handling
  *
+ * single, capacity:
+ *  Boring cases used to test coalescing machinery itself and stats
+ *  more than protocol behavior.
+ *
  * MSS is defined as 4096 - header because if it is too small
  * (i.e. 1500 MTU - header), it will result in many packets,
  * increasing the "large" test case's flakiness. This is because
@@ -126,6 +130,9 @@ static int total_hdr_len = -1;
 static int ethhdr_proto = -1;
 static bool ipip;
 static uint64_t txtime_ns;
+static int num_flows = 4;
+
+#define CAPACITY_PAYLOAD_LEN 200
 
 #define TXTIME_DELAY_MS 5
 
@@ -389,6 +396,45 @@ static void create_packet(void *buf, int seq_offset, int ack_offset,
 	fill_datalinklayer(buf);
 }
 
+static void create_capacity_packet(void *buf, int flow_id, int pkt_idx, int psh)
+{
+	int seq_offset = pkt_idx * CAPACITY_PAYLOAD_LEN;
+	struct tcphdr *tcph;
+
+	create_packet(buf, seq_offset, 0, CAPACITY_PAYLOAD_LEN, 0);
+
+	/* Customize for this flow id */
+	memset(buf + total_hdr_len, 'a' + flow_id, CAPACITY_PAYLOAD_LEN);
+
+	tcph = buf + tcp_offset;
+	tcph->source = htons(SPORT + flow_id);
+	tcph->psh = psh;
+	tcph->check = 0;
+	tcph->check = tcp_checksum(tcph, CAPACITY_PAYLOAD_LEN);
+}
+
+/* Send a capacity test, 2 packets per flow, all first packets then all second:
+ *  A1 B1 C1 D1 ... A2 B2 C2 D2 ...
+ */
+static void send_capacity(int fd, struct sockaddr_ll *daddr)
+{
+	static char buf[MAX_HDR_LEN + CAPACITY_PAYLOAD_LEN];
+	int pkt_size = total_hdr_len + CAPACITY_PAYLOAD_LEN;
+	int i;
+
+	/* Send first packet of each flow (no PSH) */
+	for (i = 0; i < num_flows; i++) {
+		create_capacity_packet(buf, i, 0, 0);
+		write_packet(fd, buf, pkt_size, daddr);
+	}
+
+	/* Send second packet of each flow (with PSH to flush) */
+	for (i = 0; i < num_flows; i++) {
+		create_capacity_packet(buf, i, 1, 1);
+		write_packet(fd, buf, pkt_size, daddr);
+	}
+}
+
 #ifndef TH_CWR
 #define TH_CWR 0x80
 #endif
@@ -1085,6 +1131,93 @@ static void check_recv_pkts(int fd, int *correct_payload,
 	printf("Test succeeded\n\n");
 }
 
+static void check_capacity_pkts(int fd)
+{
+	static char buffer[IP_MAXPACKET + ETH_HLEN + 1];
+	struct iphdr *iph = (struct iphdr *)(buffer + ETH_HLEN);
+	struct ipv6hdr *ip6h = (struct ipv6hdr *)(buffer + ETH_HLEN);
+	const char *fail_reason = NULL;
+	int flow_order[num_flows * 2];
+	int coalesced[num_flows];
+	struct tcphdr *tcph;
+	int ip_ext_len = 0;
+	int total_data = 0;
+	int pkt_size = -1;
+	int data_len = 0;
+	int num_pkt = 0;
+	int num_coal = 0;
+	int flow_id;
+	int sport;
+
+	memset(coalesced, 0, sizeof(coalesced));
+	memset(flow_order, -1, sizeof(flow_order));
+
+	while (total_data < num_flows * CAPACITY_PAYLOAD_LEN * 2) {
+		ip_ext_len = 0;
+		pkt_size = recv(fd, buffer, IP_MAXPACKET + ETH_HLEN + 1, 0);
+		if (pkt_size < 0)
+			recv_error(fd, errno);
+
+		if (iph->version == 4)
+			ip_ext_len = (iph->ihl - 5) * 4;
+		else if (ip6h->version == 6 && ip6h->nexthdr != IPPROTO_TCP)
+			ip_ext_len = MIN_EXTHDR_SIZE;
+
+		tcph = (struct tcphdr *)(buffer + tcp_offset + ip_ext_len);
+
+		/* FIN packet terminates reception */
+		if (tcph->fin)
+			break;
+
+		sport = ntohs(tcph->source);
+		flow_id = sport - SPORT;
+
+		if (flow_id < 0 || flow_id >= num_flows) {
+			vlog("Invalid flow_id %d from sport %d\n",
+			     flow_id, sport);
+			fail_reason = fail_reason ?: "invalid packet";
+			continue;
+		}
+
+		/* Calculate payload length */
+		if (pkt_size == ETH_ZLEN && iph->version == 4) {
+			data_len = ntohs(iph->tot_len)
+				- sizeof(struct tcphdr) - sizeof(struct iphdr);
+		} else {
+			data_len = pkt_size - total_hdr_len - ip_ext_len;
+		}
+
+		flow_order[num_pkt] = flow_id;
+		coalesced[flow_id] = data_len;
+
+		if (data_len == CAPACITY_PAYLOAD_LEN * 2) {
+			num_coal++;
+		} else {
+			vlog("Pkt %d: flow %d, sport %d, len %d (expected %d)\n",
+			     num_pkt, flow_id, sport, data_len,
+			     CAPACITY_PAYLOAD_LEN * 2);
+			fail_reason = fail_reason ?: "not coalesced";
+		}
+
+		num_pkt++;
+		total_data += data_len;
+	}
+
+	if (!fail_reason) {
+		vlog("All %d flows coalesced correctly\n", num_flows);
+		printf("Test succeeded\n\n");
+	} else {
+		printf("FAILED\n");
+	}
+
+	/* Always print stats for external validation */
+	printf("STATS: received=%d wire=%d coalesced=%d\n",
+	       num_pkt, num_pkt + num_coal, num_coal);
+
+	if (fail_reason)
+		error(1, 0, "capacity test failed %s", fail_reason);
+}
+
 static void gro_sender(void)
 {
 	int bufsize = 4 * 1024 * 1024; /* 4 MB */
@@ -1103,7 +1236,7 @@ static void gro_sender(void)
 	/* Enable SO_TXTIME unless test case generates more than one flow
 	 * SO_TXTIME could result in qdisc layer sorting the packets at sender.
 	 */
-	if (true) {
+	if (strcmp(testname, "single") && strcmp(testname, "capacity")) {
 		struct sock_txtime so_txtime = { .clockid = CLOCK_MONOTONIC, };
 		struct timespec ts;
 
@@ -1250,6 +1383,19 @@ static void gro_sender(void)
 
 		send_large(txfd, &daddr, remainder + 1);
 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
+
+	/* machinery sub-tests */
+	} else if (strcmp(testname, "single") == 0) {
+		static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
+
+		create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
+		write_packet(txfd, buf, total_hdr_len + PAYLOAD_LEN, &daddr);
+		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
+	} else if (strcmp(testname, "capacity") == 0) {
+		send_capacity(txfd, &daddr);
+		usleep(fin_delay_us);
+		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
+
 	} else {
 		error(1, 0, "Unknown testcase: %s", testname);
 	}
@@ -1445,6 +1591,15 @@ static void gro_receiver(void)
 		correct_payload[2] = remainder + 1;
 		printf("last segment sent individually: ");
 		check_recv_pkts(rxfd, correct_payload, 3);
+
+	/* machinery sub-tests */
+	} else if (strcmp(testname, "single") == 0) {
+		printf("single data packet: ");
+		correct_payload[0] = PAYLOAD_LEN;
+		check_recv_pkts(rxfd, correct_payload, 1);
+	} else if (strcmp(testname, "capacity") == 0) {
+		check_capacity_pkts(rxfd);
+
 	} else {
 		error(1, 0, "Test case error: unknown testname %s", testname);
 	}
@@ -1462,6 +1617,7 @@ static void parse_args(int argc, char **argv)
 		{ "ipv4", no_argument, NULL, '4' },
 		{ "ipv6", no_argument, NULL, '6' },
 		{ "ipip", no_argument, NULL, 'e' },
+		{ "num-flows", required_argument, NULL, 'n' },
 		{ "rx", no_argument, NULL, 'r' },
 		{ "saddr", required_argument, NULL, 's' },
 		{ "smac", required_argument, NULL, 'S' },
@@ -1471,7 +1627,7 @@ static void parse_args(int argc, char **argv)
 	};
 	int c;
 
-	while ((c = getopt_long(argc, argv, "46d:D:ei:rs:S:t:v", opts, NULL)) != -1) {
+	while ((c = getopt_long(argc, argv, "46d:D:ei:n:rs:S:t:v", opts, NULL)) != -1) {
 		switch (c) {
 		case '4':
 			proto = PF_INET;
@@ -1495,6 +1651,9 @@ static void parse_args(int argc, char **argv)
 		case 'i':
 			ifname = optarg;
 			break;
+		case 'n':
+			num_flows = atoi(optarg);
+			break;
 		case 'r':
 			tx_socket = false;
 			break;
diff --git a/tools/testing/selftests/drivers/net/hw/gro_hw.py b/tools/testing/selftests/drivers/net/hw/gro_hw.py
new file mode 100755
index 000000000000..3bca19e8f339
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/hw/gro_hw.py
@@ -0,0 +1,271 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+"""
+HW GRO tests focusing on device machinery like stats, rather than protocol
+processing.
+"""
+
+import glob
+import re
+
+from lib.py import ksft_run, ksft_exit, ksft_pr
+from lib.py import ksft_eq, ksft_ge
+from lib.py import NetDrvEpEnv, NetdevFamily
+from lib.py import KsftSkipEx
+from lib.py import bkg, cmd, defer, ethtool, ip
+
+
+# gro.c uses hardcoded DPORT=8000
+GRO_DPORT = 8000
+
+
+def _get_queue_stats(cfg, queue_id):
+    """Get stats for a specific Rx queue."""
+    cfg.wait_hw_stats_settle()
+    data = cfg.netnl.qstats_get({"ifindex": cfg.ifindex, "scope": ["queue"]},
+                                dump=True)
+    for q in data:
+        if q.get('queue-type') == 'rx' and q.get('queue-id') == queue_id:
+            return q
+    return {}
+
+
+def _resolve_dmac(cfg, ipver):
+    """Find the destination MAC address for sending packets."""
+    attr = "dmac" + ipver
+    if hasattr(cfg, attr):
+        return getattr(cfg, attr)
+
+    route = ip(f"-{ipver} route get {cfg.addr_v[ipver]}",
+               json=True, host=cfg.remote)[0]
+    gw = route.get("gateway")
+    if not gw:
+        setattr(cfg, attr, cfg.dev['address'])
+        return getattr(cfg, attr)
+
+    cmd(f"ping -c1 -W0 -I{cfg.remote_ifname} {gw}", host=cfg.remote)
+    neigh = ip(f"neigh get {gw} dev {cfg.remote_ifname}",
+               json=True, host=cfg.remote)[0]
+    setattr(cfg, attr, neigh['lladdr'])
+    return getattr(cfg, attr)
+
+
+def _setup_isolated_queue(cfg):
+    """Set up an isolated queue for testing using ntuple filter.
+
+    Remove queue 1 from the default RSS context and steer test traffic to it.
+    """
+    test_queue = 1
+
+    qcnt = len(glob.glob(f"/sys/class/net/{cfg.ifname}/queues/rx-*"))
+    if qcnt < 2:
+        raise KsftSkipEx(f"Need at least 2 queues, have {qcnt}")
+
+    # Remove queue 1 from default RSS context by setting its weight to 0
+    weights = ["1"] * qcnt
+    weights[test_queue] = "0"
+    ethtool(f"-X {cfg.ifname} weight " + " ".join(weights))
+    defer(ethtool, f"-X {cfg.ifname} default")
+
+    # Set up ntuple filter to steer our test traffic to the isolated queue
+    flow  = f"flow-type tcp{cfg.addr_ipver} "
+    flow += f"dst-ip {cfg.addr} dst-port {GRO_DPORT} action {test_queue}"
+    output = ethtool(f"-N {cfg.ifname} {flow}").stdout
+    ntuple_id = int(output.split()[-1])
+    defer(ethtool, f"-N {cfg.ifname} delete {ntuple_id}")
+
+    return test_queue
+
+
+def _run_gro_test(cfg, test_name, num_flows=None, ignore_fail=False):
+    """Run gro binary with given test and return output."""
+    if not hasattr(cfg, "bin_remote"):
+        cfg.bin_local = cfg.net_lib_dir / "gro"
+        cfg.bin_remote = cfg.remote.deploy(cfg.bin_local)
+
+    ipver = cfg.addr_ipver
+    protocol = f"--ipv{ipver}"
+    dmac = _resolve_dmac(cfg, ipver)
+
+    base_args = [
+        protocol,
+        f"--dmac {dmac}",
+        f"--smac {cfg.remote_dev['address']}",
+        f"--daddr {cfg.addr}",
+        f"--saddr {cfg.remote_addr_v[ipver]}",
+        f"--test {test_name}",
+    ]
+    if num_flows:
+        base_args.append(f"--num-flows {num_flows}")
+
+    args = " ".join(base_args)
+
+    rx_cmd = f"{cfg.bin_local} {args} --rx --iface {cfg.ifname}"
+    tx_cmd = f"{cfg.bin_remote} {args} --iface {cfg.remote_ifname}"
+
+    with bkg(rx_cmd, ksft_ready=True, exit_wait=True, fail=False) as rx_proc:
+        cmd(tx_cmd, host=cfg.remote)
+
+    if not ignore_fail:
+        ksft_eq(rx_proc.ret, 0)
+        if rx_proc.ret != 0:
+            ksft_pr(rx_proc)
+
+    return rx_proc.stdout
+
+
+def _require_hw_gro_stats(cfg, queue_id):
+    """Check if device reports HW GRO stats for the queue."""
+    stats = _get_queue_stats(cfg, queue_id)
+    required = ['rx-packets', 'rx-hw-gro-packets', 'rx-hw-gro-wire-packets']
+    for stat in required:
+        if stat not in stats:
+            raise KsftSkipEx(f"Driver does not report '{stat}' via qstats")
+
+
+def _set_ethtool_feat(cfg, current, feats):
+    """Set ethtool features with defer to restore original state."""
+    s2n = {True: "on", False: "off"}
+
+    new = ["-K", cfg.ifname]
+    old = ["-K", cfg.ifname]
+    no_change = True
+    for name, state in feats.items():
+        new += [name, s2n[state]]
+        old += [name, s2n[current[name]["active"]]]
+
+        if current[name]["active"] != state:
+            no_change = False
+            if current[name]["fixed"]:
+                raise KsftSkipEx(f"Device does not support {name}")
+    if no_change:
+        return
+
+    eth_cmd = ethtool(" ".join(new))
+    defer(ethtool, " ".join(old))
+
+    # If ethtool printed something kernel must have modified some features
+    if eth_cmd.stdout:
+        ksft_pr(eth_cmd)
+
+
+def _setup_hw_gro(cfg):
+    """Enable HW GRO on the device, disabling SW GRO."""
+    feat = ethtool(f"-k {cfg.ifname}", json=True)[0]
+
+    # Try to disable SW GRO and enable HW GRO
+    _set_ethtool_feat(cfg, feat,
+                      {"generic-receive-offload": False,
+                       "rx-gro-hw": True,
+                       "large-receive-offload": False})
+
+    # Some NICs treat HW GRO as a GRO sub-feature so disabling GRO
+    # will also clear HW GRO. Use a hack of installing XDP generic
+    # to skip SW GRO, even when enabled.
+    feat = ethtool(f"-k {cfg.ifname}", json=True)[0]
+    if not feat["rx-gro-hw"]["active"]:
+        ksft_pr("Driver clears HW GRO when SW GRO is cleared, using generic XDP workaround")
+        prog = cfg.net_lib_dir / "xdp_dummy.bpf.o"
+        ip(f"link set dev {cfg.ifname} xdpgeneric obj {prog} sec xdp")
+        defer(ip, f"link set dev {cfg.ifname} xdpgeneric off")
+
+        # Attaching XDP may change features, fetch the latest state
+        feat = ethtool(f"-k {cfg.ifname}", json=True)[0]
+
+        _set_ethtool_feat(cfg, feat,
+                          {"generic-receive-offload": True,
+                           "rx-gro-hw": True,
+                           "large-receive-offload": False})
+
+
+def _check_gro_stats(cfg, test_queue, stats_before,
+                     expect_rx, expect_gro, expect_wire):
+    """Validate GRO stats against expected values."""
+    stats_after = _get_queue_stats(cfg, test_queue)
+
+    rx_delta = (stats_after.get('rx-packets', 0) -
+                stats_before.get('rx-packets', 0))
+    gro_delta = (stats_after.get('rx-hw-gro-packets', 0) -
+                 stats_before.get('rx-hw-gro-packets', 0))
+    wire_delta = (stats_after.get('rx-hw-gro-wire-packets', 0) -
+                  stats_before.get('rx-hw-gro-wire-packets', 0))
+
+    ksft_eq(rx_delta, expect_rx, comment="rx-packets")
+    ksft_eq(gro_delta, expect_gro, comment="rx-hw-gro-packets")
+    ksft_eq(wire_delta, expect_wire, comment="rx-hw-gro-wire-packets")
+
+
+def test_gro_stats_single(cfg):
+    """
+    Test that a single packet doesn't affect GRO stats.
+
+    Send a single packet that cannot be coalesced (nothing to coalesce with).
+    GRO stats should not increase since no coalescing occurred.
+    rx-packets should increase by 2 (1 data + 1 FIN).
+    """
+    _setup_hw_gro(cfg)
+
+    test_queue = _setup_isolated_queue(cfg)
+    _require_hw_gro_stats(cfg, test_queue)
+
+    stats_before = _get_queue_stats(cfg, test_queue)
+
+    _run_gro_test(cfg, "single")
+
+    # 1 data + 1 FIN = 2 rx-packets, no coalescing
+    _check_gro_stats(cfg, test_queue, stats_before,
+                     expect_rx=2, expect_gro=0, expect_wire=0)
+
+
+def test_gro_stats_full(cfg):
+    """
+    Test GRO stats when overwhelming HW GRO capacity.
+
+    Send 500 flows to exceed HW GRO flow capacity on a single queue.
+    This should result in some packets not being coalesced.
+    Validate that qstats match what gro.c observed.
+    """
+    _setup_hw_gro(cfg)
+
+    test_queue = _setup_isolated_queue(cfg)
+    _require_hw_gro_stats(cfg, test_queue)
+
+    num_flows = 500
+    stats_before = _get_queue_stats(cfg, test_queue)
+
+    # Run capacity test - will likely fail because not all packets coalesce
+    output = _run_gro_test(cfg, "capacity", num_flows=num_flows,
+                           ignore_fail=True)
+
+    # Parse gro.c output: "STATS: received=X wire=Y coalesced=Z"
+    match = re.search(r'STATS: received=(\d+) wire=(\d+) coalesced=(\d+)',
+                      output)
+    if not match:
+        raise KsftSkipEx(f"Could not parse gro.c output: {output}")
+
+    rx_frames = int(match.group(2))
+    gro_coalesced = int(match.group(3))
+
+    ksft_ge(gro_coalesced, 1,
+            comment="At least some packets should coalesce")
+
+    # received + 1 FIN, coalesced super-packets, coalesced * 2 wire packets
+    _check_gro_stats(cfg, test_queue, stats_before,
+                     expect_rx=rx_frames + 1,
+                     expect_gro=gro_coalesced,
+                     expect_wire=gro_coalesced * 2)
+
+
+def main() -> None:
+    """ Ksft boiler plate main """
+
+    with NetDrvEpEnv(__file__, nsim_test=False) as cfg:
+        cfg.netnl = NetdevFamily()
+        ksft_run([test_gro_stats_single,
+                  test_gro_stats_full], args=(cfg,))
+    ksft_exit()
+
+
+if __name__ == "__main__":
+    main()
-- 
2.53.0

[PATCH net-next v4 5/6] selftests: drv-net: gro: add test for packet ordering

[Jakub Kicinski]

Add a test to check if the NIC reorders packets if the hit GRO.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 tools/testing/selftests/net/lib/gro.c         | 38 +++++++++++++++++--
 .../selftests/drivers/net/hw/gro_hw.py        | 29 ++++++++++++--
 2 files changed, 61 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/net/lib/gro.c b/tools/testing/selftests/net/lib/gro.c
index 41794b9f6f8a..3e611ae25f61 100644
--- a/tools/testing/selftests/net/lib/gro.c
+++ b/tools/testing/selftests/net/lib/gro.c
@@ -131,6 +131,7 @@ static int ethhdr_proto = -1;
 static bool ipip;
 static uint64_t txtime_ns;
 static int num_flows = 4;
+static bool order_check;
 
 #define CAPACITY_PAYLOAD_LEN 200
 
@@ -1136,6 +1137,7 @@ static void check_capacity_pkts(int fd)
 	static char buffer[IP_MAXPACKET + ETH_HLEN + 1];
 	struct iphdr *iph = (struct iphdr *)(buffer + ETH_HLEN);
 	struct ipv6hdr *ip6h = (struct ipv6hdr *)(buffer + ETH_HLEN);
+	int num_pkt = 0, num_coal = 0, pkt_idx;
 	const char *fail_reason = NULL;
 	int flow_order[num_flows * 2];
 	int coalesced[num_flows];
@@ -1144,8 +1146,6 @@ static void check_capacity_pkts(int fd)
 	int total_data = 0;
 	int pkt_size = -1;
 	int data_len = 0;
-	int num_pkt = 0;
-	int num_coal = 0;
 	int flow_id;
 	int sport;
 
@@ -1203,6 +1203,34 @@ static void check_capacity_pkts(int fd)
 		total_data += data_len;
 	}
 
+	/* Check flow ordering. We expect to see all non-coalesced first segs
+	 * then interleaved coalesced and non-coalesced second frames.
+	 */
+	pkt_idx = 0;
+	for (flow_id = 0; order_check && flow_id < num_flows; flow_id++) {
+		bool coaled = coalesced[flow_id] > CAPACITY_PAYLOAD_LEN;
+
+		if (coaled)
+			continue;
+
+		if (flow_order[pkt_idx] != flow_id) {
+			vlog("Flow order mismatch (non-coalesced) at position %d: expected flow %d, got flow %d\n",
+			     pkt_idx, flow_id, flow_order[pkt_idx]);
+			fail_reason = fail_reason ?: "bad packet order (1)";
+		}
+		pkt_idx++;
+	}
+	for (flow_id = 0; order_check && flow_id < num_flows; flow_id++) {
+		bool coaled = coalesced[flow_id] > CAPACITY_PAYLOAD_LEN;
+
+		if (flow_order[pkt_idx] != flow_id) {
+			vlog("Flow order mismatch at position %d: expected flow %d, got flow %d, coalesced: %d\n",
+			     pkt_idx, flow_id, flow_order[pkt_idx], coaled);
+			fail_reason = fail_reason ?: "bad packet order (2)";
+		}
+		pkt_idx++;
+	}
+
 	if (!fail_reason) {
 		vlog("All %d flows coalesced correctly\n", num_flows);
 		printf("Test succeeded\n\n");
@@ -1622,12 +1650,13 @@ static void parse_args(int argc, char **argv)
 		{ "saddr", required_argument, NULL, 's' },
 		{ "smac", required_argument, NULL, 'S' },
 		{ "test", required_argument, NULL, 't' },
+		{ "order-check", no_argument, NULL, 'o' },
 		{ "verbose", no_argument, NULL, 'v' },
 		{ 0, 0, 0, 0 }
 	};
 	int c;
 
-	while ((c = getopt_long(argc, argv, "46d:D:ei:n:rs:S:t:v", opts, NULL)) != -1) {
+	while ((c = getopt_long(argc, argv, "46d:D:ei:n:rs:S:t:ov", opts, NULL)) != -1) {
 		switch (c) {
 		case '4':
 			proto = PF_INET;
@@ -1666,6 +1695,9 @@ static void parse_args(int argc, char **argv)
 		case 't':
 			testname = optarg;
 			break;
+		case 'o':
+			order_check = true;
+			break;
 		case 'v':
 			verbose = true;
 			break;
diff --git a/tools/testing/selftests/drivers/net/hw/gro_hw.py b/tools/testing/selftests/drivers/net/hw/gro_hw.py
index 3bca19e8f339..10e08b22ee0e 100755
--- a/tools/testing/selftests/drivers/net/hw/gro_hw.py
+++ b/tools/testing/selftests/drivers/net/hw/gro_hw.py
@@ -10,7 +10,7 @@ import glob
 import re
 
 from lib.py import ksft_run, ksft_exit, ksft_pr
-from lib.py import ksft_eq, ksft_ge
+from lib.py import ksft_eq, ksft_ge, ksft_variants
 from lib.py import NetDrvEpEnv, NetdevFamily
 from lib.py import KsftSkipEx
 from lib.py import bkg, cmd, defer, ethtool, ip
@@ -78,7 +78,8 @@ GRO_DPORT = 8000
     return test_queue
 
 
-def _run_gro_test(cfg, test_name, num_flows=None, ignore_fail=False):
+def _run_gro_test(cfg, test_name, num_flows=None, ignore_fail=False,
+                  order_check=False):
     """Run gro binary with given test and return output."""
     if not hasattr(cfg, "bin_remote"):
         cfg.bin_local = cfg.net_lib_dir / "gro"
@@ -98,6 +99,8 @@ GRO_DPORT = 8000
     ]
     if num_flows:
         base_args.append(f"--num-flows {num_flows}")
+    if order_check:
+        base_args.append("--order-check")
 
     args = " ".join(base_args)
 
@@ -257,13 +260,33 @@ def _check_gro_stats(cfg, test_queue, stats_before,
                      expect_wire=gro_coalesced * 2)
 
 
+@ksft_variants([4, 32, 512])
+def test_gro_order(cfg, num_flows):
+    """
+    Test that HW GRO preserves packet ordering between flows.
+
+    Packets may get delayed until the aggregate is released,
+    but reordering between aggregates and packet terminating
+    the aggregate and normal packets should not happen.
+
+    Note that this test is stricter than truly required.
+    Reordering packets between flows should not cause issues.
+    This test will also fail if traffic is run over an ECMP fabric.
+    """
+    _setup_hw_gro(cfg)
+    _setup_isolated_queue(cfg)
+
+    _run_gro_test(cfg, "capacity", num_flows=num_flows, order_check=True)
+
+
 def main() -> None:
     """ Ksft boiler plate main """
 
     with NetDrvEpEnv(__file__, nsim_test=False) as cfg:
         cfg.netnl = NetdevFamily()
         ksft_run([test_gro_stats_single,
-                  test_gro_stats_full], args=(cfg,))
+                  test_gro_stats_full,
+                  test_gro_order], args=(cfg,))
     ksft_exit()
 
 
-- 
2.53.0

[PATCH net-next v4 6/6] selftests: drv-net: gro: add a test for GRO depth

[Jakub Kicinski]

Reuse the long sequence test to max out the GRO contexts.
Repeat for a single queue, 8 queues, and default number
of queues but flow steering to just one.

The SW GRO's capacity should be around 64 per queue
(8 buckets, up to 8 skbs in a chain).

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
v3:
 - rename [FAIL] to [MISS] to avoid confusing NIPA
v2: https://lore.kernel.org/20260316224505.279672-7-kuba@kernel.org
 - move this "test" to SW, we can check SW GRO capacity too
v1: https://lore.kernel.org/20260205220541.2992807-10-kuba@kernel.org
---
 tools/testing/selftests/drivers/net/gro.py | 201 +++++++++++++++++++--
 1 file changed, 181 insertions(+), 20 deletions(-)

diff --git a/tools/testing/selftests/drivers/net/gro.py b/tools/testing/selftests/drivers/net/gro.py
index 2da53686354f..70709bf670c7 100755
--- a/tools/testing/selftests/drivers/net/gro.py
+++ b/tools/testing/selftests/drivers/net/gro.py
@@ -35,11 +35,18 @@ coalescing behavior.
   - large_rem: Large packet remainder handling
 """
 
+import glob
 import os
+import re
 from lib.py import ksft_run, ksft_exit, ksft_pr
 from lib.py import NetDrvEpEnv, KsftXfailEx
+from lib.py import NetdevFamily, EthtoolFamily
 from lib.py import bkg, cmd, defer, ethtool, ip
-from lib.py import ksft_variants
+from lib.py import ksft_variants, KsftNamedVariant
+
+
+# gro.c uses hardcoded DPORT=8000
+GRO_DPORT = 8000
 
 
 def _resolve_dmac(cfg, ipver):
@@ -113,6 +120,98 @@ from lib.py import ksft_variants
         ksft_pr(eth_cmd)
 
 
+def _get_queue_stats(cfg, queue_id):
+    """Get stats for a specific Rx queue."""
+    cfg.wait_hw_stats_settle()
+    data = cfg.netnl.qstats_get({"ifindex": cfg.ifindex, "scope": ["queue"]},
+                                dump=True)
+    for q in data:
+        if q.get('queue-type') == 'rx' and q.get('queue-id') == queue_id:
+            return q
+    return {}
+
+
+def _setup_isolated_queue(cfg):
+    """Set up an isolated queue for testing using ntuple filter.
+
+    Remove queue 1 from the default RSS context and steer test traffic to it.
+    """
+    test_queue = 1
+
+    qcnt = len(glob.glob(f"/sys/class/net/{cfg.ifname}/queues/rx-*"))
+    if qcnt < 2:
+        raise KsftXfailEx(f"Need at least 2 queues, have {qcnt}")
+
+    # Remove queue 1 from default RSS context by setting its weight to 0
+    weights = ["1"] * qcnt
+    weights[test_queue] = "0"
+    ethtool(f"-X {cfg.ifname} weight " + " ".join(weights))
+    defer(ethtool, f"-X {cfg.ifname} default")
+
+    # Set up ntuple filter to steer our test traffic to the isolated queue
+    flow  = f"flow-type tcp{cfg.addr_ipver} "
+    flow += f"dst-ip {cfg.addr} dst-port {GRO_DPORT} action {test_queue}"
+    output = ethtool(f"-N {cfg.ifname} {flow}").stdout
+    ntuple_id = int(output.split()[-1])
+    defer(ethtool, f"-N {cfg.ifname} delete {ntuple_id}")
+
+    return test_queue
+
+
+def _setup_queue_count(cfg, num_queues):
+    """Configure the NIC to use a specific number of queues."""
+    channels = cfg.ethnl.channels_get({'header': {'dev-index': cfg.ifindex}})
+    ch_max = channels.get('combined-max', 0)
+    qcnt = channels['combined-count']
+
+    if ch_max < num_queues:
+        raise KsftXfailEx(f"Need at least {num_queues} queues, max={ch_max}")
+
+    defer(ethtool, f"-L {cfg.ifname} combined {qcnt}")
+    ethtool(f"-L {cfg.ifname} combined {num_queues}")
+
+
+def _run_gro_bin(cfg, test_name, protocol=None, num_flows=None,
+                 order_check=False, verbose=False, fail=False):
+    """Run gro binary with given test and return the process result."""
+    if not hasattr(cfg, "bin_remote"):
+        cfg.bin_local = cfg.net_lib_dir / "gro"
+        cfg.bin_remote = cfg.remote.deploy(cfg.bin_local)
+
+    if protocol is None:
+        ipver = cfg.addr_ipver
+        protocol = f"ipv{ipver}"
+    else:
+        ipver = "6" if protocol[-1] == "6" else "4"
+
+    dmac = _resolve_dmac(cfg, ipver)
+
+    base_args = [
+        f"--{protocol}",
+        f"--dmac {dmac}",
+        f"--smac {cfg.remote_dev['address']}",
+        f"--daddr {cfg.addr_v[ipver]}",
+        f"--saddr {cfg.remote_addr_v[ipver]}",
+        f"--test {test_name}",
+    ]
+    if num_flows:
+        base_args.append(f"--num-flows {num_flows}")
+    if order_check:
+        base_args.append("--order-check")
+    if verbose:
+        base_args.append("--verbose")
+
+    args = " ".join(base_args)
+
+    rx_cmd = f"{cfg.bin_local} {args} --rx --iface {cfg.ifname}"
+    tx_cmd = f"{cfg.bin_remote} {args} --iface {cfg.remote_ifname}"
+
+    with bkg(rx_cmd, ksft_ready=True, exit_wait=True, fail=fail) as rx_proc:
+        cmd(tx_cmd, host=cfg.remote)
+
+    return rx_proc
+
+
 def _setup(cfg, mode, test_name):
     """ Setup hardware loopback mode for GRO testing. """
 
@@ -233,30 +332,14 @@ from lib.py import ksft_variants
 
     _setup(cfg, mode, test_name)
 
-    base_cmd_args = [
-        f"--{protocol}",
-        f"--dmac {_resolve_dmac(cfg, ipver)}",
-        f"--smac {cfg.remote_dev['address']}",
-        f"--daddr {cfg.addr_v[ipver]}",
-        f"--saddr {cfg.remote_addr_v[ipver]}",
-        f"--test {test_name}",
-        "--verbose"
-    ]
-    base_args = " ".join(base_cmd_args)
-
     # Each test is run 6 times to deflake, because given the receive timing,
     # not all packets that should coalesce will be considered in the same flow
     # on every try.
     max_retries = 6
     for attempt in range(max_retries):
-        rx_cmd = f"{cfg.bin_local} {base_args} --rx --iface {cfg.ifname}"
-        tx_cmd = f"{cfg.bin_remote} {base_args} --iface {cfg.remote_ifname}"
-
         fail_now = attempt >= max_retries - 1
-
-        with bkg(rx_cmd, ksft_ready=True, exit_wait=True,
-                 fail=fail_now) as rx_proc:
-            cmd(tx_cmd, host=cfg.remote)
+        rx_proc = _run_gro_bin(cfg, test_name, protocol=protocol,
+                               verbose=True, fail=fail_now)
 
         if rx_proc.ret == 0:
             return
@@ -270,11 +353,89 @@ from lib.py import ksft_variants
         ksft_pr(f"Attempt {attempt + 1}/{max_retries} failed, retrying...")
 
 
+def _capacity_variants():
+    """Generate variants for capacity test: mode x queue setup."""
+    setups = [
+        ("isolated", _setup_isolated_queue),
+        ("1q", lambda cfg: _setup_queue_count(cfg, 1)),
+        ("8q", lambda cfg: _setup_queue_count(cfg, 8)),
+    ]
+    for mode in ["sw", "hw", "lro"]:
+        for name, func in setups:
+            yield KsftNamedVariant(f"{mode}_{name}", mode, func)
+
+
+@ksft_variants(_capacity_variants())
+def test_gro_capacity(cfg, mode, setup_func):
+    """
+    Probe GRO capacity.
+
+    Start with 8 flows and increase by 2x on each successful run.
+    Retry up to 3 times on failure.
+
+    Variants combine mode (sw, hw, lro) with queue setup:
+      - isolated: Use a single queue isolated from RSS
+      - 1q: Configure NIC to use 1 queue
+      - 8q: Configure NIC to use 8 queues
+    """
+    max_retries = 3
+
+    _setup(cfg, mode, "capacity")
+    queue_id = setup_func(cfg)
+
+    num_flows = 8
+    while True:
+        success = False
+        for attempt in range(max_retries):
+            if queue_id is not None:
+                stats_before = _get_queue_stats(cfg, queue_id)
+
+            rx_proc = _run_gro_bin(cfg, "capacity", num_flows=num_flows)
+            output = rx_proc.stdout
+
+            if queue_id is not None:
+                stats_after = _get_queue_stats(cfg, queue_id)
+                qstat_pkts = (stats_after.get('rx-packets', 0) -
+                              stats_before.get('rx-packets', 0))
+                gro_pkts = (stats_after.get('rx-hw-gro-packets', 0) -
+                            stats_before.get('rx-hw-gro-packets', 0))
+                qstat_str = f" qstat={qstat_pkts} hw-gro={gro_pkts}"
+            else:
+                qstat_str = ""
+
+            # Parse and print STATS line
+            match = re.search(
+                r'STATS: received=(\d+) wire=(\d+) coalesced=(\d+)', output)
+            if match:
+                received = int(match.group(1))
+                wire = int(match.group(2))
+                coalesced = int(match.group(3))
+                status = "PASS" if received == num_flows else "MISS"
+                ksft_pr(f"flows={num_flows} attempt={attempt + 1} "
+                        f"received={received} wire={wire} "
+                        f"coalesced={coalesced}{qstat_str} [{status}]")
+                if received == num_flows:
+                    success = True
+                    break
+            else:
+                ksft_pr(rx_proc)
+                ksft_pr(f"flows={num_flows} attempt={attempt + 1}"
+                        f"{qstat_str} [FAIL - can't parse stats]")
+
+        if not success:
+            ksft_pr(f"Stopped at {num_flows} flows")
+            break
+
+        num_flows *= 2
+
+
 def main() -> None:
     """ Ksft boiler plate main """
 
     with NetDrvEpEnv(__file__) as cfg:
-        ksft_run(cases=[test], args=(cfg,))
+        cfg.ethnl = EthtoolFamily()
+        cfg.netnl = NetdevFamily()
+        ksft_run(cases=[test, test_gro_capacity], args=(cfg,))
     ksft_exit()
 
 
-- 
2.53.0

Re: [PATCH net-next v4 0/6] selftests: drv-net: driver tests for HW GRO

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Tue, 17 Mar 2026 20:38:13 -0700 you wrote:
> Add tests for HW GRO stats, packet ordering and depth.
> 
> The ynltool and bnxt patches from v2 were applied separately.
> 
> v4:
>  - [patch 6] rename [FAIL] -> [MISS]; NIPA thinks every [FAIL]
>    means test failed, 'cause bash test don't ktap :/
> v3: https://lore.kernel.org/20260316224505.279672-1-kuba@kernel.org
>  - [patch 3] add a note about fq being needed
> v2: https://lore.kernel.org/20260207003509.3927744-1-kuba@kernel.org
>  - [patch 3] do not enable SO_TXTIME for multi-flow tests
>  - [patch 6] move the test to cover SW GRO
> v1: https://lore.kernel.org/20260205220541.2992807-1-kuba@kernel.org
> 
> [...]

Here is the summary with links:
  - [net-next,v4,1/6] selftests: net: move gro to lib for HW vs SW reuse
    https://git.kernel.org/netdev/net-next/c/8888bf4fb980
  - [net-next,v4,2/6] selftests: drv-net: give HW stats sync time extra 25% of margin
    https://git.kernel.org/netdev/net-next/c/9b29afa11660
  - [net-next,v4,3/6] selftests: drv-net: gro: use SO_TXTIME to schedule packets together
    https://git.kernel.org/netdev/net-next/c/f26d43acf12f
  - [net-next,v4,4/6] selftests: drv-net: gro: test GRO stats
    https://git.kernel.org/netdev/net-next/c/ba5d4128fca8
  - [net-next,v4,5/6] selftests: drv-net: gro: add test for packet ordering
    https://git.kernel.org/netdev/net-next/c/ff1cb3ad2abc
  - [net-next,v4,6/6] selftests: drv-net: gro: add a test for GRO depth
    https://git.kernel.org/netdev/net-next/c/7dae8ffb0987

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html