Merge branch 'selftests-rds-roce-support-follow-ups'

Allison Henderson says:

====================
selftests: rds: ROCE support follow ups

This is a follow up series to the "Add ROCE support to rds selftests"
series.  The first patch renames run.sh to rds_run.sh, which provides
a self-describing name that appears on the netdev CI dashboard.

The second patch addresses a sashiko complaint that I thought was
worth circling back for.  In the patch "pin RDS sockets to their
intended transport," sockets are pinned to the specific transport they
are meant to test.  By default, socket transports are implicitly
selected based on the network topology, but it is possible that they
can fail back to other transports if the underlying connection could
not be established.  So the patch pins them to the intended transport
to avoid false positives.

The third patch "support RDS built as loadable modules," lifts the
CONFIG_MODULES=n requirement, and updates the check_*conf_enabled()
to allow modules set to "=m" and further load the backing modules for
any component set as such.  config.sh is updated to match.

The fourth patch converts the rdma-prerequisite checks to return XFAIL
rather than SKIP, since the RDMA datapath is not run in netdev CI.

Questions, comments and feedback appreciated!
====================

Link: https://patch.msgid.link/20260602050657.26389-1-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

6 files changed, 71 insertions, 36 deletions

diff --git a/tools/testing/selftests/net/rds/Makefile b/tools/testing/selftests/net/rds/Makefile
index fe363be8e358..ec10ae24e4cf 100644
--- a/tools/testing/selftests/net/rds/Makefile
+++ b/tools/testing/selftests/net/rds/Makefile
@@ -3,7 +3,7 @@
 all:
 	@echo mk_build_dir="$(shell pwd)" > include.sh
 
-TEST_PROGS := run.sh
+TEST_PROGS := rds_run.sh
 
 TEST_FILES := \
 	include.sh \
diff --git a/tools/testing/selftests/net/rds/README.txt b/tools/testing/selftests/net/rds/README.txt
index bac6f15a80d5..8aa41148b1b5 100644
--- a/tools/testing/selftests/net/rds/README.txt
+++ b/tools/testing/selftests/net/rds/README.txt
@@ -14,9 +14,9 @@ configs required for the RDMA transport.  The kernel may optionally be
 configured to omit the coverage report as well.
 
 USAGE:
-	run.sh [-d logdir] [-l packet_loss] [-c packet_corruption]
-	       [-u packet_duplicate] [-t timeout]
-	       [-T tcp|rdma|tcp,rdma]
+	rds_run.sh [-d logdir] [-l packet_loss] [-c packet_corruption]
+	           [-u packet_duplicate] [-t timeout]
+	           [-T tcp|rdma|tcp,rdma]
 
 OPTIONS:
 	-d	Log directory.  If set, logs will be stored in the
@@ -73,5 +73,5 @@ EXAMPLE:
         "export PYTHONPATH=tools/testing/selftests/net/; \
          export SUDO_USER=example_user; \
          export RDS_LOG_DIR=tools/testing/selftests/net/rds/rds_logs; \
-         tools/testing/selftests/net/rds/run.sh -T tcp,rdma"
+         tools/testing/selftests/net/rds/rds_run.sh -T tcp,rdma"
 
diff --git a/tools/testing/selftests/net/rds/config b/tools/testing/selftests/net/rds/config
index 3d62d0c750a8..97db7ecb892a 100644
--- a/tools/testing/selftests/net/rds/config
+++ b/tools/testing/selftests/net/rds/config
@@ -1,4 +1,3 @@
-CONFIG_MODULES=n
 CONFIG_NET_NS=y
 CONFIG_NET_SCH_NETEM=y
 CONFIG_RDS=y
diff --git a/tools/testing/selftests/net/rds/config.sh b/tools/testing/selftests/net/rds/config.sh
index be0668359a07..2df2226310ef 100755
--- a/tools/testing/selftests/net/rds/config.sh
+++ b/tools/testing/selftests/net/rds/config.sh
@@ -37,9 +37,6 @@ if [[ "$CONF_FILE" != "" ]]; then
 	FLAGS=(--file "$CONF_FILE")
 fi
 
-# no modules
-scripts/config "${FLAGS[@]}" --disable CONFIG_MODULES
-
 # enable RDS
 scripts/config "${FLAGS[@]}" --enable CONFIG_RDS
 scripts/config "${FLAGS[@]}" --enable CONFIG_RDS_TCP
diff --git a/tools/testing/selftests/net/rds/run.sh b/tools/testing/selftests/net/rds/rds_run.sh
index 07af2f927a2a..cdf487ec97dc 100755
--- a/tools/testing/selftests/net/rds/run.sh
+++ b/tools/testing/selftests/net/rds/rds_run.sh
@@ -93,42 +93,62 @@ check_gcov_conf()
 	fi
 }
 
+# Checks if a kconfig is enabled (set to =y or =m)
+# $1: kconfig symbol to check
+# $2: (optional) module name backing $1
+#     Ex: check_conf_enabled CONFIG_RDS_TCP rds_tcp
+#     Modules for configs set to  =m will be probed
+#     If omitted, only a built-in (=y) config is accepted.
+# Returns on success.  exits 4 on failure
 # Kselftest framework requirement - SKIP code is 4.
 check_conf_enabled() {
-	if ! grep -x "$1=y" "$kconfig" > /dev/null 2>&1; then
-		echo "selftests: [SKIP] This test requires $1 enabled"
-		echo "Please run tools/testing/selftests/net/rds/config.sh and rebuild the kernel"
-		exit 4
+	if grep -x "$1=y" "$kconfig" > /dev/null 2>&1; then
+		return
 	fi
+	if [ -n "${2:-}" ] && grep -x "$1=m" "$kconfig" > /dev/null 2>&1; then
+		probe_module "$2"
+		return
+	fi
+	echo "selftests: [SKIP] This test requires $1 enabled"
+	echo "Please run" \
+	     "tools/testing/selftests/net/rds/config.sh and rebuild the kernel"
+	exit 4
 }
 
 check_rdma_conf_enabled() {
-	if ! grep -x "$1=y" "$kconfig" > /dev/null 2>&1; then
-		echo "selftests: [SKIP] rdma transport requires $1 enabled"
-		echo "To enable, run " \
-		     "tools/testing/selftests/net/rds/config.sh -r and rebuild"
-		exit 4
+	if grep -x "$1=y" "$kconfig" > /dev/null 2>&1; then
+		return
+	fi
+	if [ -n "${2:-}" ] && grep -x "$1=m" "$kconfig" > /dev/null 2>&1; then
+		probe_module "$2"
+		return
 	fi
+	echo "selftests: [XFAIL] rdma transport requires $1 enabled"
+	echo "To enable, run" \
+	     "tools/testing/selftests/net/rds/config.sh -r and rebuild"
+	exit 2
 }
 
-check_conf_disabled() {
-	if grep -x "$1=y" "$kconfig" > /dev/null 2>&1; then
-		echo "selftests: [SKIP] This test requires $1 disabled"
-		echo "Please run tools/testing/selftests/net/rds/config.sh and rebuild the kernel"
+# Load the module backing a config that is built as a loadable module
+# (=m).  Built-in (=y) configs are already available and don't reach
+# here.  Exits with the SKIP code if a required module cannot be loaded.
+probe_module() {
+	if ! modprobe -q "$1"; then
+		echo "selftests: [SKIP] could not load required module $1"
 		exit 4
 	fi
 }
+
 check_conf() {
-	check_conf_enabled CONFIG_NET_SCH_NETEM
-	check_conf_enabled CONFIG_VETH
+	check_conf_enabled CONFIG_NET_SCH_NETEM sch_netem
+	check_conf_enabled CONFIG_VETH veth
 	check_conf_enabled CONFIG_NET_NS
-	check_conf_enabled CONFIG_RDS_TCP
-	check_conf_enabled CONFIG_RDS
-	check_conf_disabled CONFIG_MODULES
+	check_conf_enabled CONFIG_RDS_TCP rds_tcp
+	check_conf_enabled CONFIG_RDS rds
 }
 
 # Check kernel config and host environment for RDS-RDMA support.
-# Exits with SKIP (4) if the user requested rdma but prerequisites
+# Exits with XFAIL (2) if the user requested rdma but prerequisites
 # are not met.
 check_rdma_conf()
 {
@@ -139,13 +159,13 @@ check_rdma_conf()
 
 	# Kconfig will enforce CONFIG_INFINIBAND_* as dependencies
 	# of CONFIG_RDMA_RXE
-	check_rdma_conf_enabled CONFIG_RDMA_RXE
-	check_rdma_conf_enabled CONFIG_RDS_RDMA
+	check_rdma_conf_enabled CONFIG_RDMA_RXE rdma_rxe
+	check_rdma_conf_enabled CONFIG_RDS_RDMA rds_rdma
 
 	if ! which rdma > /dev/null 2>&1; then
-		echo "selftests: [SKIP] rdma transport requires the 'rdma'" \
-		      " tool (iproute2)"
-		exit 4
+		echo "selftests: [XFAIL] rdma transport requires the 'rdma'" \
+		      "tool (iproute2)"
+		exit 2
 	fi
 }
 
@@ -209,8 +229,9 @@ while getopts "d:l:c:u:t:T:" opt; do
       TRANSPORT=${OPTARG}
       ;;
     :)
-      echo "USAGE: run.sh [-d logdir] [-l packet_loss] [-c packet_corruption]" \
-           "[-u packet_duplicate] [-t timeout] [-T tcp|rdma|tcp,rdma]"
+      echo "USAGE: rds_run.sh [-d logdir] [-l packet_loss]" \
+           "[-c packet_corruption] [-u packet_duplicate] [-t timeout]" \
+           "[-T tcp|rdma|tcp,rdma]"
       exit 1
       ;;
     ?)
@@ -224,7 +245,7 @@ done
 IFS=',' read -ra transports <<< "$TRANSPORT"
 for t in "${transports[@]}"; do
     if [ "$t" != "tcp" ] && [ "$t" != "rdma" ]; then
-        echo "run.sh: unknown transport '$t' (expected tcp or rdma)"
+        echo "rds_run.sh: unknown transport '$t' (expected tcp or rdma)"
         exit 1
     fi
 done
diff --git a/tools/testing/selftests/net/rds/test.py b/tools/testing/selftests/net/rds/test.py
index 08f2a846a8ab..9e4df01cb0d4 100755
--- a/tools/testing/selftests/net/rds/test.py
+++ b/tools/testing/selftests/net/rds/test.py
@@ -59,6 +59,14 @@ rdma_addrs = [
 OP_FLAG_TCP     = 0x1
 OP_FLAG_RDMA    = 0x2
 
+# from include/uapi/linux/rds.h: SO_RDS_TRANSPORT pins a socket to a
+# specific RDS transport so connection setup cannot silently fall back
+# to another (e.g. loopback) transport.
+SOL_RDS          = 276
+SO_RDS_TRANSPORT = 8
+RDS_TRANS_TCP    = 2
+RDS_TRANS_IB     = 0
+
 signal_handler_label = ""
 
 tap_idx = 0
@@ -214,11 +222,21 @@ def snd_rcv_packets(env):
             netns_socket(netns_list[0], socket.AF_RDS, socket.SOCK_SEQPACKET),
             netns_socket(netns_list[1], socket.AF_RDS, socket.SOCK_SEQPACKET),
         ]
+
+        # Pin the sockets to the TCP transport so it doesn't fail over to a
+        # different transport during this test
+        for s in sockets:
+            s.setsockopt(SOL_RDS, SO_RDS_TRANSPORT, RDS_TRANS_TCP)
     elif flags & OP_FLAG_RDMA:
         sockets = [
             socket.socket(socket.AF_RDS, socket.SOCK_SEQPACKET),
             socket.socket(socket.AF_RDS, socket.SOCK_SEQPACKET),
         ]
+
+        # Pin the sockets to the RDMA transport so it doesn't fail over to a
+        # different transport during this test
+        for s in sockets:
+            s.setsockopt(SOL_RDS, SO_RDS_TRANSPORT, RDS_TRANS_IB)
     else:
         raise RuntimeError(f"Invalid transport flag sets no transports: {flags}")