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6.15.0

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Family netdev netlink specification¶

Contents

  • Family netdev netlink specification

    • Summary

    • Operations

      • dev-get

      • dev-add-ntf

      • dev-del-ntf

      • dev-change-ntf

      • page-pool-get

      • page-pool-add-ntf

      • page-pool-del-ntf

      • page-pool-change-ntf

      • page-pool-stats-get

      • queue-get

      • napi-get

      • qstats-get

      • bind-rx

      • napi-set

    • Multicast groups

    • Definitions

      • xdp-act

      • xdp-rx-metadata

      • xsk-flags

      • queue-type

      • qstats-scope

    • Attribute sets

      • dev

      • io-uring-provider-info

      • page-pool

      • page-pool-info

      • page-pool-stats

      • napi

      • xsk-info

      • queue

      • qstats

      • queue-id

      • dmabuf

Summary¶

netdev configuration over generic netlink.

Operations¶

dev-get¶

Get / dump information about a netdev.

attribute-set

dev

do
request
attributes

[ifindex]

reply
attributes

[ifindex, xdp-features, xdp-zc-max-segs, xdp-rx-metadata-features, xsk-features]

dump
reply
attributes

[ifindex, xdp-features, xdp-zc-max-segs, xdp-rx-metadata-features, xsk-features]

dev-add-ntf¶

Notification about device appearing.

notify

dev-get

mcgrp

mgmt

dev-del-ntf¶

Notification about device disappearing.

notify

dev-get

mcgrp

mgmt

dev-change-ntf¶

Notification about device configuration being changed.

notify

dev-get

mcgrp

mgmt

page-pool-get¶

Get / dump information about Page Pools. (Only Page Pools associated with a net_device can be listed.)

attribute-set

page-pool

config-cond

page-pool

do
request
attributes

[id]

reply
attributes

[id, ifindex, napi-id, inflight, inflight-mem, detach-time, dmabuf, io-uring]

dump
reply
attributes

[id, ifindex, napi-id, inflight, inflight-mem, detach-time, dmabuf, io-uring]

page-pool-add-ntf¶

Notification about page pool appearing.

notify

page-pool-get

mcgrp

page-pool

config-cond

page-pool

page-pool-del-ntf¶

Notification about page pool disappearing.

notify

page-pool-get

mcgrp

page-pool

config-cond

page-pool

page-pool-change-ntf¶

Notification about page pool configuration being changed.

notify

page-pool-get

mcgrp

page-pool

config-cond

page-pool

page-pool-stats-get¶

Get page pool statistics.

attribute-set

page-pool-stats

config-cond

page-pool-stats

do
request
attributes

[info]

reply
attributes

[info, alloc-fast, alloc-slow, alloc-slow-high-order, alloc-empty, alloc-refill, alloc-waive, recycle-cached, recycle-cache-full, recycle-ring, recycle-ring-full, recycle-released-refcnt]

dump
reply
attributes

[info, alloc-fast, alloc-slow, alloc-slow-high-order, alloc-empty, alloc-refill, alloc-waive, recycle-cached, recycle-cache-full, recycle-ring, recycle-ring-full, recycle-released-refcnt]

queue-get¶

Get queue information from the kernel. Only configured queues will be reported (as opposed to all available hardware queues).

attribute-set

queue

do
request
attributes

[ifindex, type, id]

reply
attributes

[id, type, napi-id, ifindex, dmabuf, io-uring, xsk]

dump
request
attributes

[ifindex]

reply
attributes

[id, type, napi-id, ifindex, dmabuf, io-uring, xsk]

napi-get¶

Get information about NAPI instances configured on the system.

attribute-set

napi

do
request
attributes

[id]

reply
attributes

[id, ifindex, irq, pid, defer-hard-irqs, gro-flush-timeout, irq-suspend-timeout]

dump
request
attributes

[ifindex]

reply
attributes

[id, ifindex, irq, pid, defer-hard-irqs, gro-flush-timeout, irq-suspend-timeout]

qstats-get¶

Get / dump fine grained statistics. Which statistics are reported depends on the device and the driver, and whether the driver stores software counters per-queue.

attribute-set

qstats

dump
request
attributes

[ifindex, scope]

reply
attributes

[ifindex, queue-type, queue-id, rx-packets, rx-bytes, tx-packets, tx-bytes]

bind-rx¶

Bind dmabuf to netdev

attribute-set

dmabuf

flags

[admin-perm]

do
request
attributes

[ifindex, fd, queues]

reply
attributes

[id]

napi-set¶

Set configurable NAPI instance settings.

attribute-set

napi

flags

[admin-perm]

do
request
attributes

[id, defer-hard-irqs, gro-flush-timeout, irq-suspend-timeout]

Multicast groups¶

  • mgmt

  • page-pool

Definitions¶

xdp-act¶

type

flags

entries
basic

XDP features set supported by all drivers (XDP_ABORTED, XDP_DROP, XDP_PASS, XDP_TX)

redirect

The netdev supports XDP_REDIRECT

ndo-xmit

This feature informs if netdev implements ndo_xdp_xmit callback.

xsk-zerocopy

This feature informs if netdev supports AF_XDP in zero copy mode.

hw-offload

This feature informs if netdev supports XDP hw offloading.

rx-sg

This feature informs if netdev implements non-linear XDP buffer support in the driver napi callback.

ndo-xmit-sg

This feature informs if netdev implements non-linear XDP buffer support in ndo_xdp_xmit callback.

xdp-rx-metadata¶

type

flags

entries
timestamp

Device is capable of exposing receive HW timestamp via bpf_xdp_metadata_rx_timestamp().

hash

Device is capable of exposing receive packet hash via bpf_xdp_metadata_rx_hash().

vlan-tag

Device is capable of exposing receive packet VLAN tag via bpf_xdp_metadata_rx_vlan_tag().

xsk-flags¶

type

flags

entries
tx-timestamp

HW timestamping egress packets is supported by the driver.

tx-checksum

L3 checksum HW offload is supported by the driver.

tx-launch-time-fifo

Launch time HW offload is supported by the driver.

queue-type¶

type

enum

entries
  • rx

  • tx

qstats-scope¶

type

flags

entries
  • queue

Attribute sets¶

dev¶

ifindex (u32)¶

doc

netdev ifindex

pad (pad)¶

xdp-features (u64)¶

doc

Bitmask of enabled xdp-features.

enum

xdp-act

xdp-zc-max-segs (u32)¶

doc

max fragment count supported by ZC driver

xdp-rx-metadata-features (u64)¶

doc

Bitmask of supported XDP receive metadata features. See XDP RX Metadata for more details.

enum

xdp-rx-metadata

xsk-features (u64)¶

doc

Bitmask of enabled AF_XDP features.

enum

xsk-flags

io-uring-provider-info¶

page-pool¶

id (uint)¶

doc

Unique ID of a Page Pool instance.

ifindex (u32)¶

doc

ifindex of the netdev to which the pool belongs. May be reported as 0 if the page pool was allocated for a netdev which got destroyed already (page pools may outlast their netdevs because they wait for all memory to be returned).

napi-id (uint)¶

doc

Id of NAPI using this Page Pool instance.

inflight (uint)¶

doc

Number of outstanding references to this page pool (allocated but yet to be freed pages). Allocated pages may be held in socket receive queues, driver receive ring, page pool recycling ring, the page pool cache, etc.

inflight-mem (uint)¶

doc

Amount of memory held by inflight pages.

detach-time (uint)¶

doc

Seconds in CLOCK_BOOTTIME of when Page Pool was detached by the driver. Once detached Page Pool can no longer be used to allocate memory. Page Pools wait for all the memory allocated from them to be freed before truly disappearing. “Detached” Page Pools cannot be “re-attached”, they are just waiting to disappear. Attribute is absent if Page Pool has not been detached, and can still be used to allocate new memory.

dmabuf (u32)¶

doc

ID of the dmabuf this page-pool is attached to.

io-uring (nest)¶

doc

io-uring memory provider information.

nested-attributes

io-uring-provider-info

page-pool-info¶

id¶

ifindex¶

page-pool-stats¶

info (nest)¶

doc

Page pool identifying information.

nested-attributes

page-pool-info

alloc-fast (uint)¶

value

8

alloc-slow (uint)¶

alloc-slow-high-order (uint)¶

alloc-empty (uint)¶

alloc-refill (uint)¶

alloc-waive (uint)¶

recycle-cached (uint)¶

recycle-cache-full (uint)¶

recycle-ring (uint)¶

recycle-ring-full (uint)¶

recycle-released-refcnt (uint)¶

napi¶

ifindex (u32)¶

doc

ifindex of the netdevice to which NAPI instance belongs.

id (u32)¶

doc

ID of the NAPI instance.

irq (u32)¶

doc

The associated interrupt vector number for the napi

pid (u32)¶

doc

PID of the napi thread, if NAPI is configured to operate in threaded mode. If NAPI is not in threaded mode (i.e. uses normal softirq context), the attribute will be absent.

defer-hard-irqs (u32)¶

doc

The number of consecutive empty polls before IRQ deferral ends and hardware IRQs are re-enabled.

gro-flush-timeout (uint)¶

doc

The timeout, in nanoseconds, of when to trigger the NAPI watchdog timer which schedules NAPI processing. Additionally, a non-zero value will also prevent GRO from flushing recent super-frames at the end of a NAPI cycle. This may add receive latency in exchange for reducing the number of frames processed by the network stack.

irq-suspend-timeout (uint)¶

doc

The timeout, in nanoseconds, of how long to suspend irq processing, if event polling finds events

xsk-info¶

queue¶

id (u32)¶

doc

Queue index; most queue types are indexed like a C array, with indexes starting at 0 and ending at queue count - 1. Queue indexes are scoped to an interface and queue type.

ifindex (u32)¶

doc

ifindex of the netdevice to which the queue belongs.

type (u32)¶

doc

Queue type as rx, tx. Each queue type defines a separate ID space. XDP TX queues allocated in the kernel are not linked to NAPIs and thus not listed. AF_XDP queues will have more information set in the xsk attribute.

enum

queue-type

napi-id (u32)¶

doc

ID of the NAPI instance which services this queue.

dmabuf (u32)¶

doc

ID of the dmabuf attached to this queue, if any.

io-uring (nest)¶

doc

io_uring memory provider information.

nested-attributes

io-uring-provider-info

xsk (nest)¶

doc

XSK information for this queue, if any.

nested-attributes

xsk-info

qstats¶

ifindex (u32)¶

doc

ifindex of the netdevice to which stats belong.

queue-type (u32)¶

doc

Queue type as rx, tx, for queue-id.

enum

queue-type

queue-id (u32)¶

doc

Queue ID, if stats are scoped to a single queue instance.

scope (uint)¶

doc

What object type should be used to iterate over the stats.

enum

qstats-scope

rx-packets (uint)¶

doc

Number of wire packets successfully received and passed to the stack. For drivers supporting XDP, XDP is considered the first layer of the stack, so packets consumed by XDP are still counted here.

value

8

rx-bytes (uint)¶

doc

Successfully received bytes, see rx-packets.

tx-packets (uint)¶

doc

Number of wire packets successfully sent. Packet is considered to be successfully sent once it is in device memory (usually this means the device has issued a DMA completion for the packet).

tx-bytes (uint)¶

doc

Successfully sent bytes, see tx-packets.

rx-alloc-fail (uint)¶

doc

Number of times skb or buffer allocation failed on the Rx datapath. Allocation failure may, or may not result in a packet drop, depending on driver implementation and whether system recovers quickly.

rx-hw-drops (uint)¶

doc

Number of all packets which entered the device, but never left it, including but not limited to: packets dropped due to lack of buffer space, processing errors, explicit or implicit policies and packet filters.

rx-hw-drop-overruns (uint)¶

doc

Number of packets dropped due to transient lack of resources, such as buffer space, host descriptors etc.

rx-csum-complete (uint)¶

doc

Number of packets that were marked as CHECKSUM_COMPLETE.

rx-csum-unnecessary (uint)¶

doc

Number of packets that were marked as CHECKSUM_UNNECESSARY.

rx-csum-none (uint)¶

doc

Number of packets that were not checksummed by device.

rx-csum-bad (uint)¶

doc

Number of packets with bad checksum. The packets are not discarded, but still delivered to the stack.

rx-hw-gro-packets (uint)¶

doc

Number of packets that were coalesced from smaller packets by the device. Counts only packets coalesced with the HW-GRO netdevice feature, LRO-coalesced packets are not counted.

rx-hw-gro-bytes (uint)¶

doc

See rx-hw-gro-packets.

rx-hw-gro-wire-packets (uint)¶

doc

Number of packets that were coalesced to bigger packetss with the HW-GRO netdevice feature. LRO-coalesced packets are not counted.

rx-hw-gro-wire-bytes (uint)¶

doc

See rx-hw-gro-wire-packets.

rx-hw-drop-ratelimits (uint)¶

doc

Number of the packets dropped by the device due to the received packets bitrate exceeding the device rate limit.

tx-hw-drops (uint)¶

doc

Number of packets that arrived at the device but never left it, encompassing packets dropped for reasons such as processing errors, as well as those affected by explicitly defined policies and packet filtering criteria.

tx-hw-drop-errors (uint)¶

doc

Number of packets dropped because they were invalid or malformed.

tx-csum-none (uint)¶

doc

Number of packets that did not require the device to calculate the checksum.

tx-needs-csum (uint)¶

doc

Number of packets that required the device to calculate the checksum. This counter includes the number of GSO wire packets for which device calculated the L4 checksum.

tx-hw-gso-packets (uint)¶

doc

Number of packets that necessitated segmentation into smaller packets by the device.

tx-hw-gso-bytes (uint)¶

doc

See tx-hw-gso-packets.

tx-hw-gso-wire-packets (uint)¶

doc

Number of wire-sized packets generated by processing tx-hw-gso-packets

tx-hw-gso-wire-bytes (uint)¶

doc

See tx-hw-gso-wire-packets.

tx-hw-drop-ratelimits (uint)¶

doc

Number of the packets dropped by the device due to the transmit packets bitrate exceeding the device rate limit.

tx-stop (uint)¶

doc

Number of times driver paused accepting new tx packets from the stack to this queue, because the queue was full. Note that if BQL is supported and enabled on the device the networking stack will avoid queuing a lot of data at once.

tx-wake (uint)¶

doc

Number of times driver re-started accepting send requests to this queue from the stack.

queue-id¶

id¶

type¶

dmabuf¶

ifindex (u32)¶

doc

netdev ifindex to bind the dmabuf to.

queues (nest)¶

doc

receive queues to bind the dmabuf to.

nested-attributes

queue-id

multi-attr

True

fd (u32)¶

doc

dmabuf file descriptor to bind.

id (u32)¶

doc

id of the dmabuf binding

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