Merge branch 'selftests-fixes-for-kernel-ci'

Petr Machata says:

====================
selftests: Fixes for kernel CI

As discussed on the bi-weekly call on Jan 30, and in mailing around
kernel CI effort, some changes are desirable in the suite of forwarding
selftests the better to work with the CI tooling. Namely:

- The forwarding selftests use a configuration file where names of
interfaces are defined and various variables can be overridden. There
is also forwarding.config.sample that users can use as a template to
refer to when creating the config file. What happens a fair bit is
that users either do not know about this at all, or simply forget, and
are confused by cryptic failures about interfaces that cannot be
created.

In patches #1 - #3 have lib.sh just be the single source of truth with
regards to which variables exist. That includes the topology variables
which were previously only in the sample file, and any "tweak
variables", such as what tools to use, sleep times, etc.

forwarding.config.sample then becomes just a placeholder with a couple
examples. Unless specific HW should be exercised, or specific tools
used, the defaults are usually just fine.

- Several net/forwarding/ selftests (and one net/ one) cannot be run on
veth pairs, they need an actual HW interface to run on. They are
generic in the sense that any capable HW should pass them, which is
why they have been put to net/forwarding/ as opposed to drivers/net/,
but they do not generalize to veth. The fact that these tests are in
net/forwarding/, but still complaining when run, is confusing.

In patches #4 - #6 move these tests to a new directory
drivers/net/hw.

- The following patches extend the codebase to handle well test results
other than pass and fail.

Patch #7 is preparatory. It converts several log_test_skip to XFAIL,
so that tests do not spuriously end up returning non-0 when they
are not supposed to.

In patches #8 - #10, introduce some missing ksft constants, then support
having those constants in RET, and then finally in EXIT_STATUS.

- The traffic scheduler tests generate a large amount of network traffic
to test the behavior of the scheduler. This demands a relatively
high-performance computer. On slow machines, such as with a debugging
kernel, the test would spuriously fail.

It can still be useful to "go through the motions" though, to possibly
catch bugs in setup of the scheduler graph and passing packets around.
Thus we still want to run the tests, just with lowered demands.

To that end, in patches #11 - #12, introduce an environment variable
KSFT_MACHINE_SLOW, with obvious meaning. Tests can then make checks
more lenient, such as mark failures as XFAIL. A helper, xfail_on_slow,
is provided to mark performance-sensitive parts of the selftest.

- In patch #13, use a similar mechanism to mark a NH group stats
selftest to XFAIL HW stats tests when run on VETH pairs.

- All these changes complicate the hitherto straightforward logging and
checking logic, so in patch #14, add a selftest that checks this
functionality in lib.sh.

v1 (vs. an RFC circulated through linux-kselftest):
- Patch #9:
- Clarify intended usage by s/set_ret/ret_set_ksft_status/,
s/nret/ksft_status/
====================

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

tools/testing/selftests/drivers/net/hw/Makefile

···
+# SPDX-License-Identifier: GPL-2.0+ OR MIT
+
+TEST_PROGS = \
+	devlink_port_split.py \
+	ethtool.sh \
+	ethtool_extended_state.sh \
+	ethtool_mm.sh \
+	ethtool_rmon.sh \
+	hw_stats_l3.sh \
+	hw_stats_l3_gre.sh \
+	loopback.sh \
+	#
+
+TEST_FILES := \
+	ethtool_lib.sh \
+	#
+
+TEST_INCLUDES := \
+	../../../net/lib.sh \
+	../../../net/forwarding/lib.sh \
+	../../../net/forwarding/ipip_lib.sh \
+	../../../net/forwarding/tc_common.sh \
+	#
+
+include ../../../lib.mk

tools/testing/selftests/drivers/net/hw/settings

···
+timeout=0

tools/testing/selftests/drivers/net/mlxsw/mlxsw_lib.sh

···
 	local src=$1; shift
 
 	if ! mlxsw_on_spectrum "$rev"; then
-		log_test_skip $src:$caller "(Spectrum-$rev only)"
+		log_test_xfail $src:$caller "(Spectrum-$rev only)"
 		return 1
 	fi
 }

tools/testing/selftests/drivers/net/mlxsw/spectrum-2/resource_scale.sh

···
 		RET=0
 		target=$(${current_test}_get_target "$should_fail")
 		if ((target == 0)); then
-			log_test_skip "'$current_test' should_fail=$should_fail test"
 			continue
 		fi
 

tools/testing/selftests/drivers/net/mlxsw/spectrum/resource_scale.sh

···
 			RET=0
 			target=$(${current_test}_get_target "$should_fail")
 			if ((target == 0)); then
-				log_test_skip "'$current_test' [$profile] should_fail=$should_fail test"
 				continue
 			fi
 			${current_test}_setup_prepare

tools/testing/selftests/net/Makefile

···
 TEST_PROGS += txtimestamp.sh
 TEST_PROGS += vrf-xfrm-tests.sh
 TEST_PROGS += rxtimestamp.sh
-TEST_PROGS += devlink_port_split.py
 TEST_PROGS += drop_monitor_tests.sh
 TEST_PROGS += vrf_route_leaking.sh
 TEST_PROGS += bareudp.sh

tools/testing/selftests/net/forwarding/Makefile

···
 	bridge_vlan_unaware.sh \
 	custom_multipath_hash.sh \
 	dual_vxlan_bridge.sh \
-	ethtool_extended_state.sh \
-	ethtool_mm.sh \
-	ethtool_rmon.sh \
-	ethtool.sh \
 	gre_custom_multipath_hash.sh \
 	gre_inner_v4_multipath.sh \
 	gre_inner_v6_multipath.sh \
 	gre_multipath_nh_res.sh \
 	gre_multipath_nh.sh \
 	gre_multipath.sh \
-	hw_stats_l3.sh \
-	hw_stats_l3_gre.sh \
 	ip6_forward_instats_vrf.sh \
 	ip6gre_custom_multipath_hash.sh \
 	ip6gre_flat_key.sh \
···
 	ipip_hier_gre_key.sh \
 	ipip_hier_gre_keys.sh \
 	ipip_hier_gre.sh \
+	lib_sh_test.sh \
 	local_termination.sh \
-	loopback.sh \
 	mirror_gre_bound.sh \
 	mirror_gre_bridge_1d.sh \
 	mirror_gre_bridge_1d_vlan.sh \
···
 	vxlan_symmetric.sh
 
 TEST_FILES := devlink_lib.sh \
-	ethtool_lib.sh \
 	fib_offload_lib.sh \
 	forwarding.config.sample \
 	ip6gre_lib.sh \

tools/testing/selftests/net/forwarding/README

···
 o Code shall be checked using ShellCheck [1] prior to submission.
 
 1. https://www.shellcheck.net/
+
+Customization
+=============
+
+The forwarding selftests framework uses a number of variables that
+influence its behavior and tools it invokes, and how it invokes them, in
+various ways. A number of these variables can be overridden. The way these
+overridable variables are specified is typically one of the following two
+syntaxes:
+
+	: "${VARIABLE:=default_value}"
+	VARIABLE=${VARIABLE:=default_value}
+
+Any of these variables can be overridden. Notably net/forwarding/lib.sh and
+net/lib.sh contain a number of overridable variables.
+
+One way of overriding these variables is through the environment:
+
+	PAUSE_ON_FAIL=yes ./some_test.sh
+
+The variable NETIFS is special. Since it is an array variable, there is no
+way to pass it through the environment. Its value can instead be given as
+consecutive arguments to the selftest:
+
+	./some_test.sh swp{1..8}
+
+A way to customize variables in a persistent fashion is to create a file
+named forwarding.config in this directory. lib.sh sources the file if
+present, so it can contain any shell code. Typically it will contain
+assignments of variables whose value should be overridden.
+
+forwarding.config.sample is available in the directory as an example of
+how forwarding.config might look.

tools/testing/selftests/net/forwarding/ethtool.sh tools/testing/selftests/drivers/net/hw/ethtool.sh

···
 	different_speeds_autoneg_on
 "
 NUM_NETIFS=2
-source lib.sh
+lib_dir=$(dirname "$0")
+source "$lib_dir"/../../../net/forwarding/lib.sh
 source ethtool_lib.sh
 
 h1_create()
···
 	ethtool -s $h2 autoneg on
 	ethtool -s $h1 autoneg on
 }
-
-skip_on_veth
 
 trap cleanup EXIT
 

tools/testing/selftests/net/forwarding/ethtool_extended_state.sh tools/testing/selftests/drivers/net/hw/ethtool_extended_state.sh

···
 "
 
 NUM_NETIFS=2
-source lib.sh
+lib_dir=$(dirname "$0")
+source "$lib_dir"/../../../net/forwarding/lib.sh
 source ethtool_lib.sh
 
 TIMEOUT=$((WAIT_TIMEOUT * 1000)) # ms
···
 
 	ip link set dev $swp3 down
 }
-
-skip_on_veth
 
 setup_prepare
 

tools/testing/selftests/net/forwarding/ethtool_mm.sh tools/testing/selftests/drivers/net/hw/ethtool_mm.sh

···
 NUM_NETIFS=2
 REQUIRE_MZ=no
 PREEMPTIBLE_PRIO=0
-source lib.sh
+lib_dir=$(dirname "$0")
+source "$lib_dir"/../../../net/forwarding/lib.sh
 
 traffic_test()
 {

tools/testing/selftests/net/forwarding/ethtool_rmon.sh tools/testing/selftests/drivers/net/hw/ethtool_rmon.sh

···
 "
 
 NUM_NETIFS=2
-source lib.sh
+lib_dir=$(dirname "$0")
+source "$lib_dir"/../../../net/forwarding/lib.sh
 
 ETH_FCS_LEN=4
 ETH_HLEN=$((6+6+2))
···
 
 		for if in $iface $neigh; do
 			if ! ensure_mtu $if ${bucket[0]}; then
-				log_test_skip "$if does not support the required MTU for $step"
+				log_test_xfail "$if does not support the required MTU for $step"
 				return
 			fi
 		done
···
 		jq -r ".[0].rmon[\"${set}-pktsNtoM\"][]|[.low, .high]|@tsv" 2>/dev/null)
 
 	if [ $nbuckets -eq 0 ]; then
-		log_test_skip "$iface does not support $set histogram counters"
+		log_test_xfail "$iface does not support $set histogram counters"
 		return
 	fi
 }

tools/testing/selftests/net/forwarding/forwarding.config.sample

···
 
 ##############################################################################
 # Topology description. p1 looped back to p2, p3 to p4 and so on.
-declare -A NETIFS
 
-NETIFS[p1]=veth0
-NETIFS[p2]=veth1
-NETIFS[p3]=veth2
-NETIFS[p4]=veth3
-NETIFS[p5]=veth4
-NETIFS[p6]=veth5
-NETIFS[p7]=veth6
-NETIFS[p8]=veth7
-NETIFS[p9]=veth8
-NETIFS[p10]=veth9
+NETIFS=(
+	[p1]=veth0
+	[p2]=veth1
+	[p3]=veth2
+	[p4]=veth3
+	[p5]=veth4
+	[p6]=veth5
+	[p7]=veth6
+	[p8]=veth7
+	[p9]=veth8
+	[p10]=veth9
+)
 
 # Port that does not have a cable connected.
 NETIF_NO_CABLE=eth8
 
 ##############################################################################
-# Defines
+# In addition to the topology-related variables, it is also possible to override
+# in this file other variables that net/lib.sh, net/forwarding/lib.sh or other
+# libraries or selftests use. E.g.:
 
-# IPv4 ping utility name
-PING=ping
-# IPv6 ping utility name. Some distributions use 'ping' for IPv6.
 PING6=ping6
-# Packet generator. Some distributions use 'mz'.
 MZ=mausezahn
-# mausezahn delay between transmissions in microseconds.
-MZ_DELAY=0
-# Time to wait after interfaces participating in the test are all UP
 WAIT_TIME=5
-# Whether to pause on failure or not.
-PAUSE_ON_FAIL=no
-# Whether to pause on cleanup or not.
-PAUSE_ON_CLEANUP=no
-# Type of network interface to create
-NETIF_TYPE=veth
-# Whether to create virtual interfaces (veth) or not
-NETIF_CREATE=yes
-# Timeout (in seconds) before ping exits regardless of how many packets have
-# been sent or received
-PING_TIMEOUT=5
-# Minimum ageing_time (in centiseconds) supported by hardware
-LOW_AGEING_TIME=1000
-# Flag for tc match, supposed to be skip_sw/skip_hw which means do not process
-# filter by software/hardware
-TC_FLAG=skip_hw
-# IPv6 traceroute utility name.
-TROUTE6=traceroute6
-

tools/testing/selftests/net/forwarding/hw_stats_l3.sh tools/testing/selftests/drivers/net/hw/hw_stats_l3.sh

···
 	test_double_enable
 "
 NUM_NETIFS=4
-source lib.sh
+lib_dir=$(dirname "$0")
+source "$lib_dir"/../../../net/forwarding/lib.sh
 
 h1_create()
 {
···
 
 used=$(ip -j stats show dev $rp1.200 group offload subgroup hw_stats_info |
 	   jq '.[].info.l3_stats.used')
-kind=$(ip -j -d link show dev $rp1 |
-	   jq -r '.[].linkinfo.info_kind')
-if [[ $used != true ]]; then
-	if [[ $kind == veth ]]; then
-		log_test_skip "l3_stats not offloaded on veth interface"
-		EXIT_STATUS=$ksft_skip
-	else
-		RET=1 log_test "l3_stats not offloaded"
-	fi
-else
-	tests_run
-fi
+[[ $used = true ]]
+check_err $? "hw_stats_info.used=$used"
+log_test "l3_stats offloaded"
+tests_run
 
 exit $EXIT_STATUS

tools/testing/selftests/net/forwarding/hw_stats_l3_gre.sh tools/testing/selftests/drivers/net/hw/hw_stats_l3_gre.sh

···
 	test_stats_tx
 "
 NUM_NETIFS=6
-source lib.sh
-source ipip_lib.sh
+lib_dir=$(dirname "$0")
+source "$lib_dir"/../../../net/forwarding/lib.sh
+source "$lib_dir"/../../../net/forwarding/ipip_lib.sh
 
 setup_prepare()
 {
···
 {
 	test_stats g2a rx
 }
-
-skip_on_veth
 
 trap cleanup EXIT
 

tools/testing/selftests/net/forwarding/ipip_lib.sh

···
 # |               $h2 +       |
 # |     192.0.2.18/28         |
 # +---------------------------+
-source lib.sh
 
 h1_create()
 {

tools/testing/selftests/net/forwarding/lib.sh

···
 # SPDX-License-Identifier: GPL-2.0
 
 ##############################################################################
+# Topology description. p1 looped back to p2, p3 to p4 and so on.
+
+declare -A NETIFS=(
+    [p1]=veth0
+    [p2]=veth1
+    [p3]=veth2
+    [p4]=veth3
+    [p5]=veth4
+    [p6]=veth5
+    [p7]=veth6
+    [p8]=veth7
+    [p9]=veth8
+    [p10]=veth9
+)
+
+# Port that does not have a cable connected.
+: "${NETIF_NO_CABLE:=eth8}"
+
+##############################################################################
 # Defines
 
-# Can be overridden by the configuration file.
-PING=${PING:=ping}
-PING6=${PING6:=ping6}
-MZ=${MZ:=mausezahn}
-MZ_DELAY=${MZ_DELAY:=0}
-ARPING=${ARPING:=arping}
-TEAMD=${TEAMD:=teamd}
-WAIT_TIME=${WAIT_TIME:=5}
-PAUSE_ON_FAIL=${PAUSE_ON_FAIL:=no}
-PAUSE_ON_CLEANUP=${PAUSE_ON_CLEANUP:=no}
-NETIF_TYPE=${NETIF_TYPE:=veth}
-NETIF_CREATE=${NETIF_CREATE:=yes}
-MCD=${MCD:=smcrouted}
-MC_CLI=${MC_CLI:=smcroutectl}
-PING_COUNT=${PING_COUNT:=10}
-PING_TIMEOUT=${PING_TIMEOUT:=5}
-WAIT_TIMEOUT=${WAIT_TIMEOUT:=20}
-INTERFACE_TIMEOUT=${INTERFACE_TIMEOUT:=600}
-LOW_AGEING_TIME=${LOW_AGEING_TIME:=1000}
-REQUIRE_JQ=${REQUIRE_JQ:=yes}
-REQUIRE_MZ=${REQUIRE_MZ:=yes}
-REQUIRE_MTOOLS=${REQUIRE_MTOOLS:=no}
-STABLE_MAC_ADDRS=${STABLE_MAC_ADDRS:=no}
-TCPDUMP_EXTRA_FLAGS=${TCPDUMP_EXTRA_FLAGS:=}
-TROUTE6=${TROUTE6:=traceroute6}
+# Networking utilities.
+: "${PING:=ping}"
+: "${PING6:=ping6}"	# Some distros just use ping.
+: "${ARPING:=arping}"
+: "${TROUTE6:=traceroute6}"
+
+# Packet generator.
+: "${MZ:=mausezahn}"	# Some distributions use 'mz'.
+: "${MZ_DELAY:=0}"
+
+# Host configuration tools.
+: "${TEAMD:=teamd}"
+: "${MCD:=smcrouted}"
+: "${MC_CLI:=smcroutectl}"
+
+# Constants for netdevice bring-up:
+# Default time in seconds to wait for an interface to come up before giving up
+# and bailing out. Used during initial setup.
+: "${INTERFACE_TIMEOUT:=600}"
+# Like INTERFACE_TIMEOUT, but default for ad-hoc waiting in testing scripts.
+: "${WAIT_TIMEOUT:=20}"
+# Time to wait after interfaces participating in the test are all UP.
+: "${WAIT_TIME:=5}"
+
+# Whether to pause on, respectively, after a failure and before cleanup.
+: "${PAUSE_ON_FAIL:=no}"
+: "${PAUSE_ON_CLEANUP:=no}"
+
+# Whether to create virtual interfaces, and what netdevice type they should be.
+: "${NETIF_CREATE:=yes}"
+: "${NETIF_TYPE:=veth}"
+
+# Constants for ping tests:
+# How many packets should be sent.
+: "${PING_COUNT:=10}"
+# Timeout (in seconds) before ping exits regardless of how many packets have
+# been sent or received
+: "${PING_TIMEOUT:=5}"
+
+# Minimum ageing_time (in centiseconds) supported by hardware
+: "${LOW_AGEING_TIME:=1000}"
+
+# Whether to check for availability of certain tools.
+: "${REQUIRE_JQ:=yes}"
+: "${REQUIRE_MZ:=yes}"
+: "${REQUIRE_MTOOLS:=no}"
+
+# Whether to override MAC addresses on interfaces participating in the test.
+: "${STABLE_MAC_ADDRS:=no}"
+
+# Flags for tcpdump
+: "${TCPDUMP_EXTRA_FLAGS:=}"
+
+# Flags for TC filters.
+: "${TC_FLAG:=skip_hw}"
+
+# Whether the machine is "slow" -- i.e. might be incapable of running tests
+# involving heavy traffic. This might be the case on a debug kernel, a VM, or
+# e.g. a low-power board.
+: "${KSFT_MACHINE_SLOW:=no}"
 
 net_forwarding_dir=$(dirname "$(readlink -e "${BASH_SOURCE[0]}")")
 
···
 	fi
 }
 
-skip_on_veth()
-{
-	local kind=$(ip -j -d link show dev ${NETIFS[p1]} |
-		jq -r '.[].linkinfo.info_kind')
-
-	if [[ $kind == veth ]]; then
-		echo "SKIP: Test cannot be run with veth pairs"
-		exit $ksft_skip
-	fi
-}
-
 if [[ "$(id -u)" -ne 0 ]]; then
 	echo "SKIP: need root privileges"
 	exit $ksft_skip
···
 # Per-test return value. Clear at the beginning of each test.
 RET=0
 
+ret_set_ksft_status()
+{
+	local ksft_status=$1; shift
+	local msg=$1; shift
+
+	RET=$(ksft_status_merge $RET $ksft_status)
+	if (( $? )); then
+		retmsg=$msg
+	fi
+}
+
+# Whether FAILs should be interpreted as XFAILs. Internal.
+FAIL_TO_XFAIL=
+
 check_err()
 {
 	local err=$1
 	local msg=$2
 
-	if [[ $RET -eq 0 && $err -ne 0 ]]; then
-		RET=$err
-		retmsg=$msg
+	if ((err)); then
+		if [[ $FAIL_TO_XFAIL = yes ]]; then
+			ret_set_ksft_status $ksft_xfail "$msg"
+		else
+			ret_set_ksft_status $ksft_fail "$msg"
+		fi
 	fi
 }
 
···
 	local err=$1
 	local msg=$2
 
-	if [[ $RET -eq 0 && $err -eq 0 ]]; then
-		RET=1
-		retmsg=$msg
-	fi
+	check_err $((!err)) "$msg"
 }
 
 check_err_fail()
···
 	fi
 }
 
+xfail_on_slow()
+{
+	if [[ $KSFT_MACHINE_SLOW = yes ]]; then
+		FAIL_TO_XFAIL=yes "$@"
+	else
+		"$@"
+	fi
+}
+
+xfail_on_veth()
+{
+	local dev=$1; shift
+	local kind
+
+	kind=$(ip -j -d link show dev $dev |
+			jq -r '.[].linkinfo.info_kind')
+	if [[ $kind = veth ]]; then
+		FAIL_TO_XFAIL=yes "$@"
+	else
+		"$@"
+	fi
+}
+
+log_test_result()
+{
+	local test_name=$1; shift
+	local opt_str=$1; shift
+	local result=$1; shift
+	local retmsg=$1; shift
+
+	printf "TEST: %-60s  [%s]\n" "$test_name $opt_str" "$result"
+	if [[ $retmsg ]]; then
+		printf "\t%s\n" "$retmsg"
+	fi
+}
+
+pause_on_fail()
+{
+	if [[ $PAUSE_ON_FAIL == yes ]]; then
+		echo "Hit enter to continue, 'q' to quit"
+		read a
+		[[ $a == q ]] && exit 1
+	fi
+}
+
+handle_test_result_pass()
+{
+	local test_name=$1; shift
+	local opt_str=$1; shift
+
+	log_test_result "$test_name" "$opt_str" " OK "
+}
+
+handle_test_result_fail()
+{
+	local test_name=$1; shift
+	local opt_str=$1; shift
+
+	log_test_result "$test_name" "$opt_str" FAIL "$retmsg"
+	pause_on_fail
+}
+
+handle_test_result_xfail()
+{
+	local test_name=$1; shift
+	local opt_str=$1; shift
+
+	log_test_result "$test_name" "$opt_str" XFAIL "$retmsg"
+	pause_on_fail
+}
+
+handle_test_result_skip()
+{
+	local test_name=$1; shift
+	local opt_str=$1; shift
+
+	log_test_result "$test_name" "$opt_str" SKIP "$retmsg"
+}
+
 log_test()
 {
 	local test_name=$1
···
 		opt_str="($opt_str)"
 	fi
 
-	if [[ $RET -ne 0 ]]; then
-		EXIT_STATUS=1
-		printf "TEST: %-60s  [FAIL]\n" "$test_name $opt_str"
-		if [[ ! -z "$retmsg" ]]; then
-			printf "\t%s\n" "$retmsg"
-		fi
-		if [ "${PAUSE_ON_FAIL}" = "yes" ]; then
-			echo "Hit enter to continue, 'q' to quit"
-			read a
-			[ "$a" = "q" ] && exit 1
-		fi
-		return 1
+	if ((RET == ksft_pass)); then
+		handle_test_result_pass "$test_name" "$opt_str"
+	elif ((RET == ksft_xfail)); then
+		handle_test_result_xfail "$test_name" "$opt_str"
+	elif ((RET == ksft_skip)); then
+		handle_test_result_skip "$test_name" "$opt_str"
+	else
+		handle_test_result_fail "$test_name" "$opt_str"
 	fi
 
-	printf "TEST: %-60s  [ OK ]\n" "$test_name $opt_str"
-	return 0
+	EXIT_STATUS=$(ksft_exit_status_merge $EXIT_STATUS $RET)
+	return $RET
 }
 
 log_test_skip()
 {
-	local test_name=$1
-	local opt_str=$2
+	RET=$ksft_skip retmsg= log_test "$@"
+}
 
-	printf "TEST: %-60s  [SKIP]\n" "$test_name $opt_str"
-	return 0
+log_test_xfail()
+{
+	RET=$ksft_xfail retmsg= log_test "$@"
 }
 
 log_info()

tools/testing/selftests/net/forwarding/lib_sh_test.sh

···
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This tests the operation of lib.sh itself.
+
+ALL_TESTS="
+	test_ret
+	test_exit_status
+"
+NUM_NETIFS=0
+source lib.sh
+
+# Simulated checks.
+
+do_test()
+{
+	local msg=$1; shift
+
+	"$@"
+	check_err $? "$msg"
+}
+
+tpass()
+{
+	do_test "tpass" true
+}
+
+tfail()
+{
+	do_test "tfail" false
+}
+
+txfail()
+{
+	FAIL_TO_XFAIL=yes do_test "txfail" false
+}
+
+# Simulated tests.
+
+pass()
+{
+	RET=0
+	do_test "true" true
+	log_test "true"
+}
+
+fail()
+{
+	RET=0
+	do_test "false" false
+	log_test "false"
+}
+
+xfail()
+{
+	RET=0
+	FAIL_TO_XFAIL=yes do_test "xfalse" false
+	log_test "xfalse"
+}
+
+skip()
+{
+	RET=0
+	log_test_skip "skip"
+}
+
+slow_xfail()
+{
+	RET=0
+	xfail_on_slow do_test "slow_false" false
+	log_test "slow_false"
+}
+
+# lib.sh tests.
+
+ret_tests_run()
+{
+	local t
+
+	RET=0
+	retmsg=
+	for t in "$@"; do
+		$t
+	done
+	echo "$retmsg"
+	return $RET
+}
+
+ret_subtest()
+{
+	local expect_ret=$1; shift
+	local expect_retmsg=$1; shift
+	local -a tests=( "$@" )
+
+	local status_names=(pass fail xfail xpass skip)
+	local ret
+	local out
+
+	RET=0
+
+	# Run this in a subshell, so that our environment is intact.
+	out=$(ret_tests_run "${tests[@]}")
+	ret=$?
+
+	(( ret == expect_ret ))
+	check_err $? "RET=$ret expected $expect_ret"
+
+	[[ $out == $expect_retmsg ]]
+	check_err $? "retmsg=$out expected $expect_retmsg"
+
+	log_test "RET $(echo ${tests[@]}) -> ${status_names[$ret]}"
+}
+
+test_ret()
+{
+	ret_subtest $ksft_pass ""
+
+	ret_subtest $ksft_pass "" tpass
+	ret_subtest $ksft_fail "tfail" tfail
+	ret_subtest $ksft_xfail "txfail" txfail
+
+	ret_subtest $ksft_pass "" tpass tpass
+	ret_subtest $ksft_fail "tfail" tpass tfail
+	ret_subtest $ksft_xfail "txfail" tpass txfail
+
+	ret_subtest $ksft_fail "tfail" tfail tpass
+	ret_subtest $ksft_xfail "txfail" txfail tpass
+
+	ret_subtest $ksft_fail "tfail" tfail tfail
+	ret_subtest $ksft_fail "tfail" tfail txfail
+
+	ret_subtest $ksft_fail "tfail" txfail tfail
+
+	ret_subtest $ksft_xfail "txfail" txfail txfail
+}
+
+exit_status_tests_run()
+{
+	EXIT_STATUS=0
+	tests_run > /dev/null
+	return $EXIT_STATUS
+}
+
+exit_status_subtest()
+{
+	local expect_exit_status=$1; shift
+	local tests=$1; shift
+	local what=$1; shift
+
+	local status_names=(pass fail xfail xpass skip)
+	local exit_status
+	local out
+
+	RET=0
+
+	# Run this in a subshell, so that our environment is intact.
+	out=$(TESTS="$tests" exit_status_tests_run)
+	exit_status=$?
+
+	(( exit_status == expect_exit_status ))
+	check_err $? "EXIT_STATUS=$exit_status, expected $expect_exit_status"
+
+	log_test "EXIT_STATUS $tests$what -> ${status_names[$exit_status]}"
+}
+
+test_exit_status()
+{
+	exit_status_subtest $ksft_pass ":"
+
+	exit_status_subtest $ksft_pass "pass"
+	exit_status_subtest $ksft_fail "fail"
+	exit_status_subtest $ksft_pass "xfail"
+	exit_status_subtest $ksft_skip "skip"
+
+	exit_status_subtest $ksft_pass "pass pass"
+	exit_status_subtest $ksft_fail "pass fail"
+	exit_status_subtest $ksft_pass "pass xfail"
+	exit_status_subtest $ksft_skip "pass skip"
+
+	exit_status_subtest $ksft_fail "fail pass"
+	exit_status_subtest $ksft_pass "xfail pass"
+	exit_status_subtest $ksft_skip "skip pass"
+
+	exit_status_subtest $ksft_fail "fail fail"
+	exit_status_subtest $ksft_fail "fail xfail"
+	exit_status_subtest $ksft_fail "fail skip"
+
+	exit_status_subtest $ksft_fail "xfail fail"
+	exit_status_subtest $ksft_fail "skip fail"
+
+	exit_status_subtest $ksft_pass "xfail xfail"
+	exit_status_subtest $ksft_skip "xfail skip"
+	exit_status_subtest $ksft_skip "skip xfail"
+
+	exit_status_subtest $ksft_skip "skip skip"
+
+	KSFT_MACHINE_SLOW=yes \
+		exit_status_subtest $ksft_pass "slow_xfail" ": slow"
+
+	KSFT_MACHINE_SLOW=no \
+		exit_status_subtest $ksft_fail "slow_xfail" ": fast"
+}
+
+trap pre_cleanup EXIT
+
+tests_run
+
+exit $EXIT_STATUS

tools/testing/selftests/net/forwarding/loopback.sh tools/testing/selftests/drivers/net/hw/loopback.sh

···
 
 ALL_TESTS="loopback_test"
 NUM_NETIFS=2
-source tc_common.sh
-source lib.sh
+lib_dir=$(dirname "$0")
+source "$lib_dir"/../../../net/forwarding/tc_common.sh
+source "$lib_dir"/../../../net/forwarding/lib.sh
 
 h1_create()
 {

tools/testing/selftests/net/forwarding/router_mpath_nh_lib.sh

···
 	local group_id=$1; shift
 	local mz="$@"
 
-	local used
-
 	nh_stats_do_test "$what" "$nh1_id" "$nh2_id" "$group_id" \
 			 nh_stats_get "${mz[@]}"
 
-	used=$(ip -s -j -d nexthop show id $group_id |
-		   jq '.[].hw_stats.used')
-	kind=$(ip -j -d link show dev $rp11 |
-		   jq -r '.[].linkinfo.info_kind')
-	if [[ $used == true ]]; then
+	xfail_on_veth $rp11 \
 		nh_stats_do_test "HW $what" "$nh1_id" "$nh2_id" "$group_id" \
 				 nh_stats_get_hw "${mz[@]}"
-	elif [[ $kind == veth ]]; then
-		log_test_skip "HW stats not offloaded on veth topology"
-	fi
 }
 
 nh_stats_test_dispatch()
···
 	local mz="$@"
 
 	local enabled
-	local kind
 
 	if ! ip nexthop help 2>&1 | grep -q hw_stats; then
 		log_test_skip "NH stats test: ip doesn't support HW stats"

tools/testing/selftests/net/forwarding/sch_ets_tests.sh

···
 ets_test_strict()
 {
 	ets_set_strict
-	ets_dwrr_test_01
-	ets_dwrr_test_12
+	xfail_on_slow ets_dwrr_test_01
+	xfail_on_slow ets_dwrr_test_12
 }
 
 ets_test_mixed()
 {
 	ets_set_mixed
-	ets_dwrr_test_01
-	ets_dwrr_test_12
+	xfail_on_slow ets_dwrr_test_01
+	xfail_on_slow ets_dwrr_test_12
 }
 
 ets_test_dwrr()
 {
 	ets_set_dwrr_uniform
-	ets_dwrr_test_012
+	xfail_on_slow ets_dwrr_test_012
+
 	ets_set_dwrr_varying
-	ets_dwrr_test_012
+	xfail_on_slow ets_dwrr_test_012
+
 	ets_change_quantum
-	ets_dwrr_test_012
+	xfail_on_slow ets_dwrr_test_012
+
 	ets_set_dwrr_two_bands
-	ets_dwrr_test_01
+	xfail_on_slow ets_dwrr_test_01
 }

tools/testing/selftests/net/forwarding/sch_red.sh

···
 ecn_test()
 {
 	install_qdisc ecn
-	do_ecn_test $BACKLOG
+	xfail_on_slow do_ecn_test $BACKLOG
 	uninstall_qdisc
 }
 
 ecn_nodrop_test()
 {
 	install_qdisc ecn nodrop
-	do_ecn_nodrop_test $BACKLOG
+	xfail_on_slow do_ecn_nodrop_test $BACKLOG
 	uninstall_qdisc
 }
 
 red_test()
 {
 	install_qdisc
-	do_red_test $BACKLOG
+	xfail_on_slow do_red_test $BACKLOG
 	uninstall_qdisc
 }
 
 red_qevent_test()
 {
 	install_qdisc qevent early_drop block 10
-	do_red_qevent_test $BACKLOG
+	xfail_on_slow do_red_qevent_test $BACKLOG
 	uninstall_qdisc
 }
 
 ecn_qevent_test()
 {
 	install_qdisc ecn qevent mark block 10
-	do_ecn_qevent_test $BACKLOG
+	xfail_on_slow do_ecn_qevent_test $BACKLOG
 	uninstall_qdisc
 }
 

tools/testing/selftests/net/forwarding/sch_tbf_core.sh

···
 	local nr=$(rate $t2 $t3 10)
 	local nr_pct=$((100 * (nr - er) / er))
 	((-5 <= nr_pct && nr_pct <= 5))
-	check_err $? "Expected rate $(humanize $er), got $(humanize $nr), which is $nr_pct% off. Required accuracy is +-5%."
+	xfail_on_slow check_err $? "Expected rate $(humanize $er), got $(humanize $nr), which is $nr_pct% off. Required accuracy is +-5%."
 
 	log_test "TC $((vlan - 10)): TBF rate ${mbit}Mbit"
 }

tools/testing/selftests/net/forwarding/tc_common.sh

···
 CHECK_TC="yes"
 
 # Can be overridden by the configuration file. See lib.sh
-TC_HIT_TIMEOUT=${TC_HIT_TIMEOUT:=1000} # ms
+: "${TC_HIT_TIMEOUT:=1000}" # ms
 
 tc_check_packets()
 {

tools/testing/selftests/net/forwarding/tc_tunnel_key.sh

···
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
-# Kselftest framework requirement - SKIP code is 4.
-ksft_skip=4
 
 ALL_TESTS="tunnel_key_nofrag_test"
 

tools/testing/selftests/net/lib.sh

···
 ##############################################################################
 # Defines
 
-WAIT_TIMEOUT=${WAIT_TIMEOUT:=20}
+: "${WAIT_TIMEOUT:=20}"
+
 BUSYWAIT_TIMEOUT=$((WAIT_TIMEOUT * 1000)) # ms
 
-# Kselftest framework requirement - SKIP code is 4.
+# Kselftest framework constants.
+ksft_pass=0
+ksft_fail=1
+ksft_xfail=2
 ksft_skip=4
+
 # namespace list created by setup_ns
 NS_LIST=""
 
 ##############################################################################
 # Helpers
+
+__ksft_status_merge()
+{
+	local a=$1; shift
+	local b=$1; shift
+	local -A weights
+	local weight=0
+
+	for i in "$@"; do
+		weights[$i]=$((weight++))
+	done
+
+	if [[ ${weights[$a]} > ${weights[$b]} ]]; then
+		echo "$a"
+		return 0
+	else
+		echo "$b"
+		return 1
+	fi
+}
+
+ksft_status_merge()
+{
+	local a=$1; shift
+	local b=$1; shift
+
+	__ksft_status_merge "$a" "$b" \
+		$ksft_pass $ksft_xfail $ksft_skip $ksft_fail
+}
+
+ksft_exit_status_merge()
+{
+	local a=$1; shift
+	local b=$1; shift
+
+	__ksft_status_merge "$a" "$b" \
+		$ksft_xfail $ksft_pass $ksft_skip $ksft_fail
+}
+
 busywait()
 {
 	local timeout=$1; shift