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().
  ...

1 files changed, 388 insertions, 0 deletions

diff --git a/Documentation/networking/devlink/devlink-port.rst b/Documentation/networking/devlink/devlink-port.rst
new file mode 100644
index 000000000..3da590953
--- /dev/null
+++ b/Documentation/networking/devlink/devlink-port.rst
@@ -0,0 +1,388 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. _devlink_port:
+
+============
+Devlink Port
+============
+
+``devlink-port`` is a port that exists on the device. It has a logically
+separate ingress/egress point of the device. A devlink port can be any one
+of many flavours. A devlink port flavour along with port attributes
+describe what a port represents.
+
+A device driver that intends to publish a devlink port sets the
+devlink port attributes and registers the devlink port.
+
+Devlink port flavours are described below.
+
+.. list-table:: List of devlink port flavours
+   :widths: 33 90
+
+   * - Flavour
+     - Description
+   * - ``DEVLINK_PORT_FLAVOUR_PHYSICAL``
+     - Any kind of physical port. This can be an eswitch physical port or any
+       other physical port on the device.
+   * - ``DEVLINK_PORT_FLAVOUR_DSA``
+     - This indicates a DSA interconnect port.
+   * - ``DEVLINK_PORT_FLAVOUR_CPU``
+     - This indicates a CPU port applicable only to DSA.
+   * - ``DEVLINK_PORT_FLAVOUR_PCI_PF``
+     - This indicates an eswitch port representing a port of PCI
+       physical function (PF).
+   * - ``DEVLINK_PORT_FLAVOUR_PCI_VF``
+     - This indicates an eswitch port representing a port of PCI
+       virtual function (VF).
+   * - ``DEVLINK_PORT_FLAVOUR_PCI_SF``
+     - This indicates an eswitch port representing a port of PCI
+       subfunction (SF).
+   * - ``DEVLINK_PORT_FLAVOUR_VIRTUAL``
+     - This indicates a virtual port for the PCI virtual function.
+
+Devlink port can have a different type based on the link layer described below.
+
+.. list-table:: List of devlink port types
+   :widths: 23 90
+
+   * - Type
+     - Description
+   * - ``DEVLINK_PORT_TYPE_ETH``
+     - Driver should set this port type when a link layer of the port is
+       Ethernet.
+   * - ``DEVLINK_PORT_TYPE_IB``
+     - Driver should set this port type when a link layer of the port is
+       InfiniBand.
+   * - ``DEVLINK_PORT_TYPE_AUTO``
+     - This type is indicated by the user when driver should detect the port
+       type automatically.
+
+PCI controllers
+---------------
+In most cases a PCI device has only one controller. A controller consists of
+potentially multiple physical, virtual functions and subfunctions. A function
+consists of one or more ports. This port is represented by the devlink eswitch
+port.
+
+A PCI device connected to multiple CPUs or multiple PCI root complexes or a
+SmartNIC, however, may have multiple controllers. For a device with multiple
+controllers, each controller is distinguished by a unique controller number.
+An eswitch is on the PCI device which supports ports of multiple controllers.
+
+An example view of a system with two controllers::
+
+                 ---------------------------------------------------------
+                 |                                                       |
+                 |           --------- ---------         ------- ------- |
+    -----------  |           | vf(s) | | sf(s) |         |vf(s)| |sf(s)| |
+    | server  |  | -------   ----/---- ---/----- ------- ---/--- ---/--- |
+    | pci rc  |=== | pf0 |______/________/       | pf1 |___/_______/     |
+    | connect |  | -------                       -------                 |
+    -----------  |     | controller_num=1 (no eswitch)                   |
+                 ------|--------------------------------------------------
+                 (internal wire)
+                       |
+                 ---------------------------------------------------------
+                 | devlink eswitch ports and reps                        |
+                 | ----------------------------------------------------- |
+                 | |ctrl-0 | ctrl-0 | ctrl-0 | ctrl-0 | ctrl-0 |ctrl-0 | |
+                 | |pf0    | pf0vfN | pf0sfN | pf1    | pf1vfN |pf1sfN | |
+                 | ----------------------------------------------------- |
+                 | |ctrl-1 | ctrl-1 | ctrl-1 | ctrl-1 | ctrl-1 |ctrl-1 | |
+                 | |pf0    | pf0vfN | pf0sfN | pf1    | pf1vfN |pf1sfN | |
+                 | ----------------------------------------------------- |
+                 |                                                       |
+                 |                                                       |
+    -----------  |           --------- ---------         ------- ------- |
+    | smartNIC|  |           | vf(s) | | sf(s) |         |vf(s)| |sf(s)| |
+    | pci rc  |==| -------   ----/---- ---/----- ------- ---/--- ---/--- |
+    | connect |  | | pf0 |______/________/       | pf1 |___/_______/     |
+    -----------  | -------                       -------                 |
+                 |                                                       |
+                 |  local controller_num=0 (eswitch)                     |
+                 ---------------------------------------------------------
+
+In the above example, the external controller (identified by controller number = 1)
+doesn't have the eswitch. Local controller (identified by controller number = 0)
+has the eswitch. The Devlink instance on the local controller has eswitch
+devlink ports for both the controllers.
+
+Function configuration
+======================
+
+Users can configure one or more function attributes before enumerating the PCI
+function. Usually it means, user should configure function attribute
+before a bus specific device for the function is created. However, when
+SRIOV is enabled, virtual function devices are created on the PCI bus.
+Hence, function attribute should be configured before binding virtual
+function device to the driver. For subfunctions, this means user should
+configure port function attribute before activating the port function.
+
+A user may set the hardware address of the function using
+`devlink port function set hw_addr` command. For Ethernet port function
+this means a MAC address.
+
+Users may also set the RoCE capability of the function using
+`devlink port function set roce` command.
+
+Users may also set the function as migratable using
+'devlink port function set migratable' command.
+
+Function attributes
+===================
+
+MAC address setup
+-----------------
+The configured MAC address of the PCI VF/SF will be used by netdevice and rdma
+device created for the PCI VF/SF.
+
+- Get the MAC address of the VF identified by its unique devlink port index::
+
+    $ devlink port show pci/0000:06:00.0/2
+    pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
+      function:
+        hw_addr 00:00:00:00:00:00
+
+- Set the MAC address of the VF identified by its unique devlink port index::
+
+    $ devlink port function set pci/0000:06:00.0/2 hw_addr 00:11:22:33:44:55
+
+    $ devlink port show pci/0000:06:00.0/2
+    pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
+      function:
+        hw_addr 00:11:22:33:44:55
+
+- Get the MAC address of the SF identified by its unique devlink port index::
+
+    $ devlink port show pci/0000:06:00.0/32768
+    pci/0000:06:00.0/32768: type eth netdev enp6s0pf0sf88 flavour pcisf pfnum 0 sfnum 88
+      function:
+        hw_addr 00:00:00:00:00:00
+
+- Set the MAC address of the SF identified by its unique devlink port index::
+
+    $ devlink port function set pci/0000:06:00.0/32768 hw_addr 00:00:00:00:88:88
+
+    $ devlink port show pci/0000:06:00.0/32768
+    pci/0000:06:00.0/32768: type eth netdev enp6s0pf0sf88 flavour pcisf pfnum 0 sfnum 88
+      function:
+        hw_addr 00:00:00:00:88:88
+
+RoCE capability setup
+---------------------
+Not all PCI VFs/SFs require RoCE capability.
+
+When RoCE capability is disabled, it saves system memory per PCI VF/SF.
+
+When user disables RoCE capability for a VF/SF, user application cannot send or
+receive any RoCE packets through this VF/SF and RoCE GID table for this PCI
+will be empty.
+
+When RoCE capability is disabled in the device using port function attribute,
+VF/SF driver cannot override it.
+
+- Get RoCE capability of the VF device::
+
+    $ devlink port show pci/0000:06:00.0/2
+    pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
+        function:
+            hw_addr 00:00:00:00:00:00 roce enable
+
+- Set RoCE capability of the VF device::
+
+    $ devlink port function set pci/0000:06:00.0/2 roce disable
+
+    $ devlink port show pci/0000:06:00.0/2
+    pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
+        function:
+            hw_addr 00:00:00:00:00:00 roce disable
+
+migratable capability setup
+---------------------------
+Live migration is the process of transferring a live virtual machine
+from one physical host to another without disrupting its normal
+operation.
+
+User who want PCI VFs to be able to perform live migration need to
+explicitly enable the VF migratable capability.
+
+When user enables migratable capability for a VF, and the HV binds the VF to VFIO driver
+with migration support, the user can migrate the VM with this VF from one HV to a
+different one.
+
+However, when migratable capability is enable, device will disable features which cannot
+be migrated. Thus migratable cap can impose limitations on a VF so let the user decide.
+
+Example of LM with migratable function configuration:
+- Get migratable capability of the VF device::
+
+    $ devlink port show pci/0000:06:00.0/2
+    pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
+        function:
+            hw_addr 00:00:00:00:00:00 migratable disable
+
+- Set migratable capability of the VF device::
+
+    $ devlink port function set pci/0000:06:00.0/2 migratable enable
+
+    $ devlink port show pci/0000:06:00.0/2
+    pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
+        function:
+            hw_addr 00:00:00:00:00:00 migratable enable
+
+- Bind VF to VFIO driver with migration support::
+
+    $ echo <pci_id> > /sys/bus/pci/devices/0000:08:00.0/driver/unbind
+    $ echo mlx5_vfio_pci > /sys/bus/pci/devices/0000:08:00.0/driver_override
+    $ echo <pci_id> > /sys/bus/pci/devices/0000:08:00.0/driver/bind
+
+Attach VF to the VM.
+Start the VM.
+Perform live migration.
+
+Subfunction
+============
+
+Subfunction is a lightweight function that has a parent PCI function on which
+it is deployed. Subfunction is created and deployed in unit of 1. Unlike
+SRIOV VFs, a subfunction doesn't require its own PCI virtual function.
+A subfunction communicates with the hardware through the parent PCI function.
+
+To use a subfunction, 3 steps setup sequence is followed:
+
+1) create - create a subfunction;
+2) configure - configure subfunction attributes;
+3) deploy - deploy the subfunction;
+
+Subfunction management is done using devlink port user interface.
+User performs setup on the subfunction management device.
+
+(1) Create
+----------
+A subfunction is created using a devlink port interface. A user adds the
+subfunction by adding a devlink port of subfunction flavour. The devlink
+kernel code calls down to subfunction management driver (devlink ops) and asks
+it to create a subfunction devlink port. Driver then instantiates the
+subfunction port and any associated objects such as health reporters and
+representor netdevice.
+
+(2) Configure
+-------------
+A subfunction devlink port is created but it is not active yet. That means the
+entities are created on devlink side, the e-switch port representor is created,
+but the subfunction device itself is not created. A user might use e-switch port
+representor to do settings, putting it into bridge, adding TC rules, etc. A user
+might as well configure the hardware address (such as MAC address) of the
+subfunction while subfunction is inactive.
+
+(3) Deploy
+----------
+Once a subfunction is configured, user must activate it to use it. Upon
+activation, subfunction management driver asks the subfunction management
+device to instantiate the subfunction device on particular PCI function.
+A subfunction device is created on the :ref:`Documentation/driver-api/auxiliary_bus.rst <auxiliary_bus>`.
+At this point a matching subfunction driver binds to the subfunction's auxiliary device.
+
+Rate object management
+======================
+
+Devlink provides API to manage tx rates of single devlink port or a group.
+This is done through rate objects, which can be one of the two types:
+
+``leaf``
+  Represents a single devlink port; created/destroyed by the driver. Since leaf
+  have 1to1 mapping to its devlink port, in user space it is referred as
+  ``pci/<bus_addr>/<port_index>``;
+
+``node``
+  Represents a group of rate objects (leafs and/or nodes); created/deleted by
+  request from the userspace; initially empty (no rate objects added). In
+  userspace it is referred as ``pci/<bus_addr>/<node_name>``, where
+  ``node_name`` can be any identifier, except decimal number, to avoid
+  collisions with leafs.
+
+API allows to configure following rate object's parameters:
+
+``tx_share``
+  Minimum TX rate value shared among all other rate objects, or rate objects
+  that parts of the parent group, if it is a part of the same group.
+
+``tx_max``
+  Maximum TX rate value.
+
+``tx_priority``
+  Allows for usage of strict priority arbiter among siblings. This
+  arbitration scheme attempts to schedule nodes based on their priority
+  as long as the nodes remain within their bandwidth limit. The higher the
+  priority the higher the probability that the node will get selected for
+  scheduling.
+
+``tx_weight``
+  Allows for usage of Weighted Fair Queuing arbitration scheme among
+  siblings. This arbitration scheme can be used simultaneously with the
+  strict priority. As a node is configured with a higher rate it gets more
+  BW relative to it's siblings. Values are relative like a percentage
+  points, they basically tell how much BW should node take relative to
+  it's siblings.
+
+``parent``
+  Parent node name. Parent node rate limits are considered as additional limits
+  to all node children limits. ``tx_max`` is an upper limit for children.
+  ``tx_share`` is a total bandwidth distributed among children.
+
+``tx_priority`` and ``tx_weight`` can be used simultaneously. In that case
+nodes with the same priority form a WFQ subgroup in the sibling group
+and arbitration among them is based on assigned weights.
+
+Arbitration flow from the high level:
+
+#. Choose a node, or group of nodes with the highest priority that stays
+   within the BW limit and are not blocked. Use ``tx_priority`` as a
+   parameter for this arbitration.
+
+#. If group of nodes have the same priority perform WFQ arbitration on
+   that subgroup. Use ``tx_weight`` as a parameter for this arbitration.
+
+#. Select the winner node, and continue arbitration flow among it's children,
+   until leaf node is reached, and the winner is established.
+
+#. If all the nodes from the highest priority sub-group are satisfied, or
+   overused their assigned BW, move to the lower priority nodes.
+
+Driver implementations are allowed to support both or either rate object types
+and setting methods of their parameters. Additionally driver implementation
+may export nodes/leafs and their child-parent relationships.
+
+Terms and Definitions
+=====================
+
+.. list-table:: Terms and Definitions
+   :widths: 22 90
+
+   * - Term
+     - Definitions
+   * - ``PCI device``
+     - A physical PCI device having one or more PCI buses consists of one or
+       more PCI controllers.
+   * - ``PCI controller``
+     -  A controller consists of potentially multiple physical functions,
+        virtual functions and subfunctions.
+   * - ``Port function``
+     -  An object to manage the function of a port.
+   * - ``Subfunction``
+     -  A lightweight function that has parent PCI function on which it is
+        deployed.
+   * - ``Subfunction device``
+     -  A bus device of the subfunction, usually on a auxiliary bus.
+   * - ``Subfunction driver``
+     -  A device driver for the subfunction auxiliary device.
+   * - ``Subfunction management device``
+     -  A PCI physical function that supports subfunction management.
+   * - ``Subfunction management driver``
+     -  A device driver for PCI physical function that supports
+        subfunction management using devlink port interface.
+   * - ``Subfunction host driver``
+     -  A device driver for PCI physical function that hosts subfunction
+        devices. In most cases it is same as subfunction management driver. When
+        subfunction is used on external controller, subfunction management and
+        host drivers are different.