ice devlink support¶
This document describes the devlink features implemented by the ice
device driver.
Parameters¶
Name |
Mode |
Notes |
|
runtime |
mutually exclusive with |
|
runtime |
mutually exclusive with |
|
permanent |
The ice hardware uses hierarchical scheduling for Tx with a fixed number of layers in the scheduling tree. Each of them are decision points. Root node represents a port, while all the leaves represent the queues. This way of configuring the Tx scheduler allows features like DCB or devlink-rate (documented below) to configure how much bandwidth is given to any given queue or group of queues, enabling fine-grained control because scheduling parameters can be configured at any given layer of the tree. The default 9-layer tree topology was deemed best for most workloads, as it gives an optimal ratio of performance to configurability. However, for some specific cases, this 9-layer topology might not be desired. One example would be sending traffic to queues that are not a multiple of 8. Because the maximum radix is limited to 8 in 9-layer topology, the 9th queue has a different parent than the rest, and it’s given more bandwidth credits. This causes a problem when the system is sending traffic to 9 queues: tx_queue_0_packets: 24163396
tx_queue_1_packets: 24164623
tx_queue_2_packets: 24163188
tx_queue_3_packets: 24163701
tx_queue_4_packets: 24163683
tx_queue_5_packets: 24164668
tx_queue_6_packets: 23327200
tx_queue_7_packets: 24163853
tx_queue_8_packets: 91101417 < Too much traffic is sent from 9th
To address this need, you can switch to a 5-layer topology, which changes the maximum topology radix to 512. With this enhancement, the performance characteristic is equal as all queues can be assigned to the same parent in the tree. The obvious drawback of this solution is a lower configuration depth of the tree. Use the You must do PCI slot powercycle for the selected topology to take effect. To verify that value has been set: $ devlink dev param show pci/0000:16:00.0 name tx_scheduling_layers |
Name |
Mode |
Description |
|
runtime |
Controls loopback behavior by tuning scheduler bandwidth. It impacts all kinds of functions: physical, virtual and subfunctions. Supported values are:
Default value of |
Info versions¶
The ice driver reports the following versions
Name |
Type |
Example |
Description |
|
fixed |
K65390-000 |
The Product Board Assembly (PBA) identifier of the board. |
|
fixed |
36 |
The Clock Generation Unit (CGU) hardware revision identifier. |
|
running |
2.1.7 |
3-digit version number of the management firmware running on the Embedded Management Processor of the device. It controls the PHY, link, access to device resources, etc. Intel documentation refers to this as the EMP firmware. |
|
running |
1.5.1 |
3-digit version number (major.minor.patch) of the API exported over the AdminQ by the management firmware. Used by the driver to identify what commands are supported. Historical versions of the kernel only displayed a 2-digit version number (major.minor). |
|
running |
0x305d955f |
Unique identifier of the source for the management firmware. |
|
running |
1.2581.0 |
Version of the Option ROM containing the UEFI driver. The version is
reported in |
|
running |
0.80 |
Version defining the format of the flash contents. |
|
running |
0x80002ec0 |
Unique identifier of the firmware image file that was loaded onto the device. Also referred to as the EETRACK identifier of the NVM. |
|
running |
ICE OS Default Package |
The name of the DDP package that is active in the device. The DDP package is loaded by the driver during initialization. Each variation of the DDP package has a unique name. |
|
running |
1.3.1.0 |
The version of the DDP package that is active in the device. Note
that both the name (as reported by |
|
running |
0xc0000001 |
Unique identifier for the DDP package loaded in the device. Also referred to as the DDP Track ID. Can be used to uniquely identify the specific DDP package. |
|
running |
1.1.2000-6.7.0 |
The version of the netlist module. This module defines the device’s Ethernet capabilities and default settings, and is used by the management firmware as part of managing link and device connectivity. |
|
running |
0xee16ced7 |
The first 4 bytes of the hash of the netlist module contents. |
|
running |
8032.16973825.6021 |
The version of Clock Generation Unit (CGU). Format: <CGU type>.<configuration version>.<firmware version>. |
Flash Update¶
The ice driver implements support for flash update using the
devlink-flash interface. It supports updating the device flash using a
combined flash image that contains the fw.mgmt, fw.undi, and
fw.netlist components.
Bits |
Behavior |
|
Do not preserve settings stored in the flash components being updated. This includes overwriting the port configuration that determines the number of physical functions the device will initialize with. |
|
Do not preserve either settings or identifiers. Overwrite everything in the flash with the contents from the provided image, without performing any preservation. This includes overwriting device identifying fields such as the MAC address, VPD area, and device serial number. It is expected that this combination be used with an image customized for the specific device. |
The ice hardware does not support overwriting only identifiers while
preserving settings, and thus DEVLINK_FLASH_OVERWRITE_IDENTIFIERS on its
own will be rejected. If no overwrite mask is provided, the firmware will be
instructed to preserve all settings and identifying fields when updating.
Reload¶
The ice driver supports activating new firmware after a flash update
using DEVLINK_CMD_RELOAD with the DEVLINK_RELOAD_ACTION_FW_ACTIVATE
action.
$ devlink dev reload pci/0000:01:00.0 reload action fw_activate
The new firmware is activated by issuing a device specific Embedded Management Processor reset which requests the device to reset and reload the EMP firmware image.
The driver does not currently support reloading the driver via
DEVLINK_RELOAD_ACTION_DRIVER_REINIT.
Port split¶
The ice driver supports port splitting only for port 0, as the FW has
a predefined set of available port split options for the whole device.
A system reboot is required for port split to be applied.
The following command will select the port split option with 4 ports:
$ devlink port split pci/0000:16:00.0/0 count 4
The list of all available port options will be printed to dynamic debug after
each split and unsplit command. The first option is the default.
ice 0000:16:00.0: Available port split options and max port speeds (Gbps):
ice 0000:16:00.0: Status Split Quad 0 Quad 1
ice 0000:16:00.0: count L0 L1 L2 L3 L4 L5 L6 L7
ice 0000:16:00.0: Active 2 100 - - - 100 - - -
ice 0000:16:00.0: 2 50 - 50 - - - - -
ice 0000:16:00.0: Pending 4 25 25 25 25 - - - -
ice 0000:16:00.0: 4 25 25 - - 25 25 - -
ice 0000:16:00.0: 8 10 10 10 10 10 10 10 10
ice 0000:16:00.0: 1 100 - - - - - - -
There could be multiple FW port options with the same port split count. When the same port split count request is issued again, the next FW port option with the same port split count will be selected.
devlink port unsplit will select the option with a split count of 1. If
there is no FW option available with split count 1, you will receive an error.
Regions¶
The ice driver implements the following regions for accessing internal
device data.
Name |
Description |
|
The contents of the entire flash chip, sometimes referred to as the device’s Non Volatile Memory. |
|
The contents of the Shadow RAM, which is loaded from the beginning of the flash. Although the contents are primarily from the flash, this area also contains data generated during device boot which is not stored in flash. |
|
The contents of the device firmware’s capabilities buffer. Useful to determine the current state and configuration of the device. |
Both the nvm-flash and shadow-ram regions can be accessed without a
snapshot. The device-caps region requires a snapshot as the contents are
sent by firmware and can’t be split into separate reads.
Users can request an immediate capture of a snapshot for all three regions
via the DEVLINK_CMD_REGION_NEW command.
$ devlink region show
pci/0000:01:00.0/nvm-flash: size 10485760 snapshot [] max 1
pci/0000:01:00.0/device-caps: size 4096 snapshot [] max 10
$ devlink region new pci/0000:01:00.0/nvm-flash snapshot 1
$ devlink region dump pci/0000:01:00.0/nvm-flash snapshot 1
$ devlink region dump pci/0000:01:00.0/nvm-flash snapshot 1
0000000000000000 0014 95dc 0014 9514 0035 1670 0034 db30
0000000000000010 0000 0000 ffff ff04 0029 8c00 0028 8cc8
0000000000000020 0016 0bb8 0016 1720 0000 0000 c00f 3ffc
0000000000000030 bada cce5 bada cce5 bada cce5 bada cce5
$ devlink region read pci/0000:01:00.0/nvm-flash snapshot 1 address 0 length 16
0000000000000000 0014 95dc 0014 9514 0035 1670 0034 db30
$ devlink region delete pci/0000:01:00.0/nvm-flash snapshot 1
$ devlink region new pci/0000:01:00.0/device-caps snapshot 1
$ devlink region dump pci/0000:01:00.0/device-caps snapshot 1
0000000000000000 01 00 01 00 00 00 00 00 01 00 00 00 00 00 00 00
0000000000000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000000000000020 02 00 02 01 32 03 00 00 0a 00 00 00 25 00 00 00
0000000000000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000000000000040 04 00 01 00 01 00 00 00 00 00 00 00 00 00 00 00
0000000000000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000000000000060 05 00 01 00 03 00 00 00 00 00 00 00 00 00 00 00
0000000000000070 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000000000000080 06 00 01 00 01 00 00 00 00 00 00 00 00 00 00 00
0000000000000090 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000000000000a0 08 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00
00000000000000b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000000000000c0 12 00 01 00 01 00 00 00 01 00 01 00 00 00 00 00
00000000000000d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000000000000e0 13 00 01 00 00 01 00 00 00 00 00 00 00 00 00 00
00000000000000f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000000000000100 14 00 01 00 01 00 00 00 00 00 00 00 00 00 00 00
0000000000000110 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000000000000120 15 00 01 00 01 00 00 00 00 00 00 00 00 00 00 00
0000000000000130 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000000000000140 16 00 01 00 01 00 00 00 00 00 00 00 00 00 00 00
0000000000000150 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000000000000160 17 00 01 00 06 00 00 00 00 00 00 00 00 00 00 00
0000000000000170 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000000000000180 18 00 01 00 01 00 00 00 01 00 00 00 08 00 00 00
0000000000000190 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000000000001a0 22 00 01 00 01 00 00 00 00 00 00 00 00 00 00 00
00000000000001b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000000000001c0 40 00 01 00 00 08 00 00 08 00 00 00 00 00 00 00
00000000000001d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00000000000001e0 41 00 01 00 00 08 00 00 00 00 00 00 00 00 00 00
00000000000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0000000000000200 42 00 01 00 00 08 00 00 00 00 00 00 00 00 00 00
0000000000000210 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
$ devlink region delete pci/0000:01:00.0/device-caps snapshot 1
Devlink Rate¶
The ice driver implements devlink-rate API. It allows for offload of
the Hierarchical QoS to the hardware. It enables user to group Virtual
Functions in a tree structure and assign supported parameters: tx_share,
tx_max, tx_priority and tx_weight to each node in a tree. So effectively
user gains an ability to control how much bandwidth is allocated for each
VF group. This is later enforced by the HW.
It is assumed that this feature is mutually exclusive with DCB performed in FW and ADQ, or any driver feature that would trigger changes in QoS, for example creation of the new traffic class. The driver will prevent DCB or ADQ configuration if user started making any changes to the nodes using devlink-rate API. To configure those features a driver reload is necessary. Correspondingly if ADQ or DCB will get configured the driver won’t export hierarchy at all, or will remove the untouched hierarchy if those features are enabled after the hierarchy is exported, but before any changes are made.
This feature is also dependent on switchdev being enabled in the system. It’s required because devlink-rate requires devlink-port objects to be present, and those objects are only created in switchdev mode.
If the driver is set to the switchdev mode, it will export internal hierarchy the moment VF’s are created. Root of the tree is always represented by the node_0. This node can’t be deleted by the user. Leaf nodes and nodes with children also can’t be deleted.
Name |
Description |
|
maximum bandwidth to be consumed by the tree Node. Rate Limit is an absolute number specifying a maximum amount of bytes a Node may consume during the course of one second. Rate limit guarantees that a link will not oversaturate the receiver on the remote end and also enforces an SLA between the subscriber and network provider. |
|
minimum bandwidth allocated to a tree node when it is not blocked. It specifies an absolute BW. While tx_max defines the maximum bandwidth the node may consume, the tx_share marks committed BW for the Node. |
|
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. Range 0-7. Nodes with priority 7 have the highest priority and are selected first, while nodes with priority 0 have the lowest priority. Nodes that have the same priority are treated equally. |
|
allows for usage of Weighted Fair Queuing arbitration scheme among siblings. This arbitration scheme can be used simultaneously with the strict priority. Range 1-200. Only relative values matter for arbitration. |
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.
# enable switchdev
$ devlink dev eswitch set pci/0000:4b:00.0 mode switchdev
# at this point driver should export internal hierarchy
$ echo 2 > /sys/class/net/ens785np0/device/sriov_numvfs
$ devlink port function rate show
pci/0000:4b:00.0/node_25: type node parent node_24
pci/0000:4b:00.0/node_24: type node parent node_0
pci/0000:4b:00.0/node_32: type node parent node_31
pci/0000:4b:00.0/node_31: type node parent node_30
pci/0000:4b:00.0/node_30: type node parent node_16
pci/0000:4b:00.0/node_19: type node parent node_18
pci/0000:4b:00.0/node_18: type node parent node_17
pci/0000:4b:00.0/node_17: type node parent node_16
pci/0000:4b:00.0/node_14: type node parent node_5
pci/0000:4b:00.0/node_5: type node parent node_3
pci/0000:4b:00.0/node_13: type node parent node_4
pci/0000:4b:00.0/node_12: type node parent node_4
pci/0000:4b:00.0/node_11: type node parent node_4
pci/0000:4b:00.0/node_10: type node parent node_4
pci/0000:4b:00.0/node_9: type node parent node_4
pci/0000:4b:00.0/node_8: type node parent node_4
pci/0000:4b:00.0/node_7: type node parent node_4
pci/0000:4b:00.0/node_6: type node parent node_4
pci/0000:4b:00.0/node_4: type node parent node_3
pci/0000:4b:00.0/node_3: type node parent node_16
pci/0000:4b:00.0/node_16: type node parent node_15
pci/0000:4b:00.0/node_15: type node parent node_0
pci/0000:4b:00.0/node_2: type node parent node_1
pci/0000:4b:00.0/node_1: type node parent node_0
pci/0000:4b:00.0/node_0: type node
pci/0000:4b:00.0/1: type leaf parent node_25
pci/0000:4b:00.0/2: type leaf parent node_25
# let's create some custom node
$ devlink port function rate add pci/0000:4b:00.0/node_custom parent node_0
# second custom node
$ devlink port function rate add pci/0000:4b:00.0/node_custom_1 parent node_custom
# reassign second VF to newly created branch
$ devlink port function rate set pci/0000:4b:00.0/2 parent node_custom_1
# assign tx_weight to the VF
$ devlink port function rate set pci/0000:4b:00.0/2 tx_weight 5
# assign tx_share to the VF
$ devlink port function rate set pci/0000:4b:00.0/2 tx_share 500Mbps