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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/dev-tools/kunit/running_tips.rst
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Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
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+.. SPDX-License-Identifier: GPL-2.0
+
+============================
+Tips For Running KUnit Tests
+============================
+
+Using ``kunit.py run`` ("kunit tool")
+=====================================
+
+Running from any directory
+--------------------------
+
+It can be handy to create a bash function like:
+
+.. code-block:: bash
+
+ function run_kunit() {
+ ( cd "$(git rev-parse --show-toplevel)" && ./tools/testing/kunit/kunit.py run "$@" )
+ }
+
+.. note::
+ Early versions of ``kunit.py`` (before 5.6) didn't work unless run from
+ the kernel root, hence the use of a subshell and ``cd``.
+
+Running a subset of tests
+-------------------------
+
+``kunit.py run`` accepts an optional glob argument to filter tests. The format
+is ``"<suite_glob>[.test_glob]"``.
+
+Say that we wanted to run the sysctl tests, we could do so via:
+
+.. code-block:: bash
+
+ $ echo -e 'CONFIG_KUNIT=y\nCONFIG_KUNIT_ALL_TESTS=y' > .kunit/.kunitconfig
+ $ ./tools/testing/kunit/kunit.py run 'sysctl*'
+
+We can filter down to just the "write" tests via:
+
+.. code-block:: bash
+
+ $ echo -e 'CONFIG_KUNIT=y\nCONFIG_KUNIT_ALL_TESTS=y' > .kunit/.kunitconfig
+ $ ./tools/testing/kunit/kunit.py run 'sysctl*.*write*'
+
+We're paying the cost of building more tests than we need this way, but it's
+easier than fiddling with ``.kunitconfig`` files or commenting out
+``kunit_suite``'s.
+
+However, if we wanted to define a set of tests in a less ad hoc way, the next
+tip is useful.
+
+Defining a set of tests
+-----------------------
+
+``kunit.py run`` (along with ``build``, and ``config``) supports a
+``--kunitconfig`` flag. So if you have a set of tests that you want to run on a
+regular basis (especially if they have other dependencies), you can create a
+specific ``.kunitconfig`` for them.
+
+E.g. kunit has one for its tests:
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit/.kunitconfig
+
+Alternatively, if you're following the convention of naming your
+file ``.kunitconfig``, you can just pass in the dir, e.g.
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit
+
+.. note::
+ This is a relatively new feature (5.12+) so we don't have any
+ conventions yet about on what files should be checked in versus just
+ kept around locally. It's up to you and your maintainer to decide if a
+ config is useful enough to submit (and therefore have to maintain).
+
+.. note::
+ Having ``.kunitconfig`` fragments in a parent and child directory is
+ iffy. There's discussion about adding an "import" statement in these
+ files to make it possible to have a top-level config run tests from all
+ child directories. But that would mean ``.kunitconfig`` files are no
+ longer just simple .config fragments.
+
+ One alternative would be to have kunit tool recursively combine configs
+ automagically, but tests could theoretically depend on incompatible
+ options, so handling that would be tricky.
+
+Setting kernel commandline parameters
+-------------------------------------
+
+You can use ``--kernel_args`` to pass arbitrary kernel arguments, e.g.
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py run --kernel_args=param=42 --kernel_args=param2=false
+
+
+Generating code coverage reports under UML
+------------------------------------------
+
+.. note::
+ TODO(brendanhiggins@google.com): There are various issues with UML and
+ versions of gcc 7 and up. You're likely to run into missing ``.gcda``
+ files or compile errors.
+
+This is different from the "normal" way of getting coverage information that is
+documented in Documentation/dev-tools/gcov.rst.
+
+Instead of enabling ``CONFIG_GCOV_KERNEL=y``, we can set these options:
+
+.. code-block:: none
+
+ CONFIG_DEBUG_KERNEL=y
+ CONFIG_DEBUG_INFO=y
+ CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y
+ CONFIG_GCOV=y
+
+
+Putting it together into a copy-pastable sequence of commands:
+
+.. code-block:: bash
+
+ # Append coverage options to the current config
+ $ ./tools/testing/kunit/kunit.py run --kunitconfig=.kunit/ --kunitconfig=tools/testing/kunit/configs/coverage_uml.config
+ # Extract the coverage information from the build dir (.kunit/)
+ $ lcov -t "my_kunit_tests" -o coverage.info -c -d .kunit/
+
+ # From here on, it's the same process as with CONFIG_GCOV_KERNEL=y
+ # E.g. can generate an HTML report in a tmp dir like so:
+ $ genhtml -o /tmp/coverage_html coverage.info
+
+
+If your installed version of gcc doesn't work, you can tweak the steps:
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py run --make_options=CC=/usr/bin/gcc-6
+ $ lcov -t "my_kunit_tests" -o coverage.info -c -d .kunit/ --gcov-tool=/usr/bin/gcov-6
+
+
+Running tests manually
+======================
+
+Running tests without using ``kunit.py run`` is also an important use case.
+Currently it's your only option if you want to test on architectures other than
+UML.
+
+As running the tests under UML is fairly straightforward (configure and compile
+the kernel, run the ``./linux`` binary), this section will focus on testing
+non-UML architectures.
+
+
+Running built-in tests
+----------------------
+
+When setting tests to ``=y``, the tests will run as part of boot and print
+results to dmesg in TAP format. So you just need to add your tests to your
+``.config``, build and boot your kernel as normal.
+
+So if we compiled our kernel with:
+
+.. code-block:: none
+
+ CONFIG_KUNIT=y
+ CONFIG_KUNIT_EXAMPLE_TEST=y
+
+Then we'd see output like this in dmesg signaling the test ran and passed:
+
+.. code-block:: none
+
+ TAP version 14
+ 1..1
+ # Subtest: example
+ 1..1
+ # example_simple_test: initializing
+ ok 1 - example_simple_test
+ ok 1 - example
+
+Running tests as modules
+------------------------
+
+Depending on the tests, you can build them as loadable modules.
+
+For example, we'd change the config options from before to
+
+.. code-block:: none
+
+ CONFIG_KUNIT=y
+ CONFIG_KUNIT_EXAMPLE_TEST=m
+
+Then after booting into our kernel, we can run the test via
+
+.. code-block:: none
+
+ $ modprobe kunit-example-test
+
+This will then cause it to print TAP output to stdout.
+
+.. note::
+ The ``modprobe`` will *not* have a non-zero exit code if any test
+ failed (as of 5.13). But ``kunit.py parse`` would, see below.
+
+.. note::
+ You can set ``CONFIG_KUNIT=m`` as well, however, some features will not
+ work and thus some tests might break. Ideally tests would specify they
+ depend on ``KUNIT=y`` in their ``Kconfig``'s, but this is an edge case
+ most test authors won't think about.
+ As of 5.13, the only difference is that ``current->kunit_test`` will
+ not exist.
+
+Pretty-printing results
+-----------------------
+
+You can use ``kunit.py parse`` to parse dmesg for test output and print out
+results in the same familiar format that ``kunit.py run`` does.
+
+.. code-block:: bash
+
+ $ ./tools/testing/kunit/kunit.py parse /var/log/dmesg
+
+
+Retrieving per suite results
+----------------------------
+
+Regardless of how you're running your tests, you can enable
+``CONFIG_KUNIT_DEBUGFS`` to expose per-suite TAP-formatted results:
+
+.. code-block:: none
+
+ CONFIG_KUNIT=y
+ CONFIG_KUNIT_EXAMPLE_TEST=m
+ CONFIG_KUNIT_DEBUGFS=y
+
+The results for each suite will be exposed under
+``/sys/kernel/debug/kunit/<suite>/results``.
+So using our example config:
+
+.. code-block:: bash
+
+ $ modprobe kunit-example-test > /dev/null
+ $ cat /sys/kernel/debug/kunit/example/results
+ ... <TAP output> ...
+
+ # After removing the module, the corresponding files will go away
+ $ modprobe -r kunit-example-test
+ $ cat /sys/kernel/debug/kunit/example/results
+ /sys/kernel/debug/kunit/example/results: No such file or directory
+
+Generating code coverage reports
+--------------------------------
+
+See Documentation/dev-tools/gcov.rst for details on how to do this.
+
+The only vaguely KUnit-specific advice here is that you probably want to build
+your tests as modules. That way you can isolate the coverage from tests from
+other code executed during boot, e.g.
+
+.. code-block:: bash
+
+ # Reset coverage counters before running the test.
+ $ echo 0 > /sys/kernel/debug/gcov/reset
+ $ modprobe kunit-example-test