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, 309 insertions, 0 deletions

diff --git a/tools/testing/selftests/drivers/net/hw/devlink_port_split.py b/tools/testing/selftests/drivers/net/hw/devlink_port_split.py
new file mode 100755
index 000000000000..2d84c7a0be6b
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/hw/devlink_port_split.py
@@ -0,0 +1,309 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+from subprocess import PIPE, Popen
+import json
+import time
+import argparse
+import collections
+import sys
+
+#
+# Test port split configuration using devlink-port lanes attribute.
+# The test is skipped in case the attribute is not available.
+#
+# First, check that all the ports with 1 lane fail to split.
+# Second, check that all the ports with more than 1 lane can be split
+# to all valid configurations (e.g., split to 2, split to 4 etc.)
+#
+
+
+# Kselftest framework requirement - SKIP code is 4
+KSFT_SKIP=4
+Port = collections.namedtuple('Port', 'bus_info name')
+
+
+def run_command(cmd, should_fail=False):
+    """
+    Run a command in subprocess.
+    Return: Tuple of (stdout, stderr).
+    """
+
+    p = Popen(cmd, stdout=PIPE, stderr=PIPE, shell=True)
+    stdout, stderr = p.communicate()
+    stdout, stderr = stdout.decode(), stderr.decode()
+
+    if stderr != "" and not should_fail:
+        print("Error sending command: %s" % cmd)
+        print(stdout)
+        print(stderr)
+    return stdout, stderr
+
+
+class devlink_ports(object):
+    """
+    Class that holds information on the devlink ports, required to the tests;
+    if_names: A list of interfaces in the devlink ports.
+    """
+
+    def get_if_names(dev):
+        """
+        Get a list of physical devlink ports.
+        Return: Array of tuples (bus_info/port, if_name).
+        """
+
+        arr = []
+
+        cmd = "devlink -j port show"
+        stdout, stderr = run_command(cmd)
+        assert stderr == ""
+        ports = json.loads(stdout)['port']
+
+        validate_devlink_output(ports, 'flavour')
+
+        for port in ports:
+            if dev in port:
+                if ports[port]['flavour'] == 'physical':
+                    arr.append(Port(bus_info=port, name=ports[port]['netdev']))
+
+        return arr
+
+    def __init__(self, dev):
+        self.if_names = devlink_ports.get_if_names(dev)
+
+
+def get_max_lanes(port):
+    """
+    Get the $port's maximum number of lanes.
+    Return: number of lanes, e.g. 1, 2, 4 and 8.
+    """
+
+    cmd = "devlink -j port show %s" % port
+    stdout, stderr = run_command(cmd)
+    assert stderr == ""
+    values = list(json.loads(stdout)['port'].values())[0]
+
+    if 'lanes' in values:
+        lanes = values['lanes']
+    else:
+        lanes = 0
+    return lanes
+
+
+def get_split_ability(port):
+    """
+    Get the $port split ability.
+    Return: split ability, true or false.
+    """
+
+    cmd = "devlink -j port show %s" % port.name
+    stdout, stderr = run_command(cmd)
+    assert stderr == ""
+    values = list(json.loads(stdout)['port'].values())[0]
+
+    return values['splittable']
+
+
+def split(k, port, should_fail=False):
+    """
+    Split $port into $k ports.
+    If should_fail == True, the split should fail. Otherwise, should pass.
+    Return: Array of sub ports after splitting.
+            If the $port wasn't split, the array will be empty.
+    """
+
+    cmd = "devlink port split %s count %s" % (port.bus_info, k)
+    stdout, stderr = run_command(cmd, should_fail=should_fail)
+
+    if should_fail:
+        if not test(stderr != "", "%s is unsplittable" % port.name):
+            print("split an unsplittable port %s" % port.name)
+            return create_split_group(port, k)
+    else:
+        if stderr == "":
+            return create_split_group(port, k)
+        print("didn't split a splittable port %s" % port.name)
+
+    return []
+
+
+def unsplit(port):
+    """
+    Unsplit $port.
+    """
+
+    cmd = "devlink port unsplit %s" % port
+    stdout, stderr = run_command(cmd)
+    test(stderr == "", "Unsplit port %s" % port)
+
+
+def exists(port, dev):
+    """
+    Check if $port exists in the devlink ports.
+    Return: True is so, False otherwise.
+    """
+
+    return any(dev_port.name == port
+               for dev_port in devlink_ports.get_if_names(dev))
+
+
+def exists_and_lanes(ports, lanes, dev):
+    """
+    Check if every port in the list $ports exists in the devlink ports and has
+    $lanes number of lanes after splitting.
+    Return: True if both are True, False otherwise.
+    """
+
+    for port in ports:
+        max_lanes = get_max_lanes(port)
+        if not exists(port, dev):
+            print("port %s doesn't exist in devlink ports" % port)
+            return False
+        if max_lanes != lanes:
+            print("port %s has %d lanes, but %s were expected"
+                  % (port, lanes, max_lanes))
+            return False
+    return True
+
+
+def test(cond, msg):
+    """
+    Check $cond and print a message accordingly.
+    Return: True is pass, False otherwise.
+    """
+
+    if cond:
+        print("TEST: %-60s [ OK ]" % msg)
+    else:
+        print("TEST: %-60s [FAIL]" % msg)
+
+    return cond
+
+
+def create_split_group(port, k):
+    """
+    Create the split group for $port.
+    Return: Array with $k elements, which are the split port group.
+    """
+
+    return list(port.name + "s" + str(i) for i in range(k))
+
+
+def split_unsplittable_port(port, k):
+    """
+    Test that splitting of unsplittable port fails.
+    """
+
+    # split to max
+    new_split_group = split(k, port, should_fail=True)
+
+    if new_split_group != []:
+        unsplit(port.bus_info)
+
+
+def split_splittable_port(port, k, lanes, dev):
+    """
+    Test that splitting of splittable port passes correctly.
+    """
+
+    new_split_group = split(k, port)
+
+    # Once the split command ends, it takes some time to the sub ifaces'
+    # to get their names. Use udevadm to continue only when all current udev
+    # events are handled.
+    cmd = "udevadm settle"
+    stdout, stderr = run_command(cmd)
+    assert stderr == ""
+
+    if new_split_group != []:
+        test(exists_and_lanes(new_split_group, lanes/k, dev),
+             "split port %s into %s" % (port.name, k))
+
+    unsplit(port.bus_info)
+
+
+def validate_devlink_output(devlink_data, target_property=None):
+    """
+    Determine if test should be skipped by checking:
+      1. devlink_data contains values
+      2. The target_property exist in devlink_data
+    """
+    skip_reason = None
+    if any(devlink_data.values()):
+        if target_property:
+            skip_reason = "{} not found in devlink output, test skipped".format(target_property)
+            for key in devlink_data:
+                if target_property in devlink_data[key]:
+                    skip_reason = None
+    else:
+        skip_reason = 'devlink output is empty, test skipped'
+
+    if skip_reason:
+        print(skip_reason)
+        sys.exit(KSFT_SKIP)
+
+
+def make_parser():
+    parser = argparse.ArgumentParser(description='A test for port splitting.')
+    parser.add_argument('--dev',
+                        help='The devlink handle of the device under test. ' +
+                             'The default is the first registered devlink ' +
+                             'handle.')
+
+    return parser
+
+
+def main(cmdline=None):
+    parser = make_parser()
+    args = parser.parse_args(cmdline)
+
+    dev = args.dev
+    if not dev:
+        cmd = "devlink -j dev show"
+        stdout, stderr = run_command(cmd)
+        assert stderr == ""
+
+        validate_devlink_output(json.loads(stdout))
+        devs = json.loads(stdout)['dev']
+        dev = list(devs.keys())[0]
+
+    cmd = "devlink dev show %s" % dev
+    stdout, stderr = run_command(cmd)
+    if stderr != "":
+        print("devlink device %s can not be found" % dev)
+        sys.exit(1)
+
+    ports = devlink_ports(dev)
+
+    found_max_lanes = False
+    for port in ports.if_names:
+        max_lanes = get_max_lanes(port.name)
+
+        # If max lanes is 0, do not test port splitting at all
+        if max_lanes == 0:
+            continue
+
+        # If 1 lane, shouldn't be able to split
+        elif max_lanes == 1:
+            test(not get_split_ability(port),
+                 "%s should not be able to split" % port.name)
+            split_unsplittable_port(port, max_lanes)
+
+        # Else, splitting should pass and all the split ports should exist.
+        else:
+            lane = max_lanes
+            test(get_split_ability(port),
+                 "%s should be able to split" % port.name)
+            while lane > 1:
+                split_splittable_port(port, lane, max_lanes, dev)
+
+                lane //= 2
+        found_max_lanes = True
+
+    if not found_max_lanes:
+        print(f"Test not started, no port of device {dev} reports max_lanes")
+        sys.exit(KSFT_SKIP)
+
+
+if __name__ == "__main__":
+    main()