selftests: forwarding: Move several selftests

The tests in net/forwarding are generally expected to be HW-independent.
There are however several tests that, while not depending on any HW in
particular, nevertheless depend on being used on HW interfaces. Placing
these selftests to net/forwarding is confusing, because the selftest will
just report it can't be run on veth pairs. At the same time, placing them
to a particular driver's selftests subdirectory would be wrong.

Instead, add a new directory, drivers/net/hw, where these generic but HW
independent selftests should be placed. Move over several such tests
including one helper library.

Since typically these tests will not be expected to run, omit the directory
drivers/net/hw from the TARGETS list in selftests/Makefile. Retain a
Makefile in the new directory itself, so that a user can make -C into that
directory and act on those tests explicitly.

Cc: Roger Quadros <rogerq@kernel.org>
Cc: Tobias Waldekranz <tobias@waldekranz.com>
Cc: Danielle Ratson <danieller@nvidia.com>
Cc: Davide Caratti <dcaratti@redhat.com>
Cc: Johannes Nixdorf <jnixdorf-oss@avm.de>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/e11dae1f62703059e9fc2240004288ac7cc15756.1711464583.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 144 insertions, 0 deletions

diff --git a/tools/testing/selftests/drivers/net/hw/ethtool_rmon.sh b/tools/testing/selftests/drivers/net/hw/ethtool_rmon.sh
new file mode 100755
index 000000000000..709433a4c886
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/hw/ethtool_rmon.sh
@@ -0,0 +1,144 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+ALL_TESTS="
+	rmon_rx_histogram
+	rmon_tx_histogram
+"
+
+NUM_NETIFS=2
+lib_dir=$(dirname "$0")
+source "$lib_dir"/../../../net/forwarding/lib.sh
+
+ETH_FCS_LEN=4
+ETH_HLEN=$((6+6+2))
+
+declare -A netif_mtu
+
+ensure_mtu()
+{
+	local iface=$1; shift
+	local len=$1; shift
+	local current=$(ip -j link show dev $iface | jq -r '.[0].mtu')
+	local required=$((len - ETH_HLEN - ETH_FCS_LEN))
+
+	if [ $current -lt $required ]; then
+		ip link set dev $iface mtu $required || return 1
+	fi
+}
+
+bucket_test()
+{
+	local iface=$1; shift
+	local neigh=$1; shift
+	local set=$1; shift
+	local bucket=$1; shift
+	local len=$1; shift
+	local num_rx=10000
+	local num_tx=20000
+	local expected=
+	local before=
+	local after=
+	local delta=
+
+	# Mausezahn does not include FCS bytes in its length - but the
+	# histogram counters do
+	len=$((len - ETH_FCS_LEN))
+
+	before=$(ethtool --json -S $iface --groups rmon | \
+		jq -r ".[0].rmon[\"${set}-pktsNtoM\"][$bucket].val")
+
+	# Send 10k one way and 20k in the other, to detect counters
+	# mapped to the wrong direction
+	$MZ $neigh -q -c $num_rx -p $len -a own -b bcast -d 10us
+	$MZ $iface -q -c $num_tx -p $len -a own -b bcast -d 10us
+
+	after=$(ethtool --json -S $iface --groups rmon | \
+		jq -r ".[0].rmon[\"${set}-pktsNtoM\"][$bucket].val")
+
+	delta=$((after - before))
+
+	expected=$([ $set = rx ] && echo $num_rx || echo $num_tx)
+
+	# Allow some extra tolerance for other packets sent by the stack
+	[ $delta -ge $expected ] && [ $delta -le $((expected + 100)) ]
+}
+
+rmon_histogram()
+{
+	local iface=$1; shift
+	local neigh=$1; shift
+	local set=$1; shift
+	local nbuckets=0
+	local step=
+
+	RET=0
+
+	while read -r -a bucket; do
+		step="$set-pkts${bucket[0]}to${bucket[1]} on $iface"
+
+		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"
+				return
+			fi
+		done
+
+		if ! bucket_test $iface $neigh $set $nbuckets ${bucket[0]}; then
+			check_err 1 "$step failed"
+			return 1
+		fi
+		log_test "$step"
+		nbuckets=$((nbuckets + 1))
+	done < <(ethtool --json -S $iface --groups rmon | \
+		jq -r ".[0].rmon[\"${set}-pktsNtoM\"][]|[.low, .high]|@tsv" 2>/dev/null)
+
+	if [ $nbuckets -eq 0 ]; then
+		log_test_skip "$iface does not support $set histogram counters"
+		return
+	fi
+}
+
+rmon_rx_histogram()
+{
+	rmon_histogram $h1 $h2 rx
+	rmon_histogram $h2 $h1 rx
+}
+
+rmon_tx_histogram()
+{
+	rmon_histogram $h1 $h2 tx
+	rmon_histogram $h2 $h1 tx
+}
+
+setup_prepare()
+{
+	h1=${NETIFS[p1]}
+	h2=${NETIFS[p2]}
+
+	for iface in $h1 $h2; do
+		netif_mtu[$iface]=$(ip -j link show dev $iface | jq -r '.[0].mtu')
+		ip link set dev $iface up
+	done
+}
+
+cleanup()
+{
+	pre_cleanup
+
+	for iface in $h2 $h1; do
+		ip link set dev $iface \
+			mtu ${netif_mtu[$iface]} \
+			down
+	done
+}
+
+check_ethtool_counter_group_support
+trap cleanup EXIT
+
+setup_prepare
+setup_wait
+
+tests_run
+
+exit $EXIT_STATUS