Switchdev¶
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Bridge offload¶
The mlx5 driver implements support for offloading bridge rules when in switchdev mode. Linux bridge FDBs are automatically offloaded when mlx5 switchdev representor is attached to bridge.
Change device to switchdev mode:
$ devlink dev eswitch set pci/0000:06:00.0 mode switchdev
Attach mlx5 switchdev representor ‘enp8s0f0’ to bridge netdev ‘bridge1’:
$ ip link set enp8s0f0 master bridge1
VLANs¶
Following bridge VLAN functions are supported by mlx5:
VLAN filtering (including multiple VLANs per port):
$ ip link set bridge1 type bridge vlan_filtering 1 $ bridge vlan add dev enp8s0f0 vid 2-3
VLAN push on bridge ingress:
$ bridge vlan add dev enp8s0f0 vid 3 pvid
VLAN pop on bridge egress:
$ bridge vlan add dev enp8s0f0 vid 3 untagged
Subfunction¶
Subfunction which are spawned over the E-switch are created only with devlink device, and by default all the SF auxiliary devices are disabled. This will allow user to configure the SF before the SF have been fully probed, which will save time.
Usage example:
Create SF:
$ devlink port add pci/0000:08:00.0 flavour pcisf pfnum 0 sfnum 11 $ devlink port function set pci/0000:08:00.0/32768 hw_addr 00:00:00:00:00:11 state active
Enable ETH auxiliary device:
$ devlink dev param set auxiliary/mlx5_core.sf.1 name enable_eth value true cmode driverinit
Now, in order to fully probe the SF, use devlink reload:
$ devlink dev reload auxiliary/mlx5_core.sf.1
mlx5 supports ETH,rdma and vdpa (vnet) auxiliary devices devlink params (see Documentation/networking/devlink/devlink-params.rst).
mlx5 supports subfunction management using devlink port (see Documentation/networking/devlink/devlink-port.rst) interface.
A subfunction has its own function capabilities and its own resources. This means a subfunction has its own dedicated queues (txq, rxq, cq, eq). These queues are neither shared nor stolen from the parent PCI function.
When a subfunction is RDMA capable, it has its own QP1, GID table, and RDMA resources neither shared nor stolen from the parent PCI function.
A subfunction has a dedicated window in PCI BAR space that is not shared with the other subfunctions or the parent PCI function. This ensures that all devices (netdev, rdma, vdpa, etc.) of the subfunction accesses only assigned PCI BAR space.
A subfunction supports eswitch representation through which it supports tc offloads. The user configures eswitch to send/receive packets from/to the subfunction port.
Subfunctions share PCI level resources such as PCI MSI-X IRQs with other subfunctions and/or with its parent PCI function.
Example mlx5 software, system, and device view:
_______
| admin |
| user |----------
|_______| |
| |
____|____ __|______ _________________
| | | | | |
| devlink | | tc tool | | user |
| tool | |_________| | applications |
|_________| | |_________________|
| | | |
| | | | Userspace
+---------|-------------|-------------------|----------|--------------------+
| | +----------+ +----------+ Kernel
| | | netdev | | rdma dev |
| | +----------+ +----------+
(devlink port add/del | ^ ^
port function set) | | |
| | +---------------|
_____|___ | | _______|_______
| | | | | mlx5 class |
| devlink | +------------+ | | drivers |
| kernel | | rep netdev | | |(mlx5_core,ib) |
|_________| +------------+ | |_______________|
| | | ^
(devlink ops) | | (probe/remove)
_________|________ | | ____|________
| subfunction | | +---------------+ | subfunction |
| management driver|----- | subfunction |---| driver |
| (mlx5_core) | | auxiliary dev | | (mlx5_core) |
|__________________| +---------------+ |_____________|
| ^
(sf add/del, vhca events) |
| (device add/del)
_____|____ ____|________
| | | subfunction |
| PCI NIC |--- activate/deactivate events--->| host driver |
|__________| | (mlx5_core) |
|_____________|
Subfunction is created using devlink port interface.
Change device to switchdev mode:
$ devlink dev eswitch set pci/0000:06:00.0 mode switchdev
Add a devlink port of subfunction flavour:
$ devlink port add pci/0000:06:00.0 flavour pcisf pfnum 0 sfnum 88 pci/0000:06:00.0/32768: type eth netdev eth6 flavour pcisf controller 0 pfnum 0 sfnum 88 external false splittable false function: hw_addr 00:00:00:00:00:00 state inactive opstate detachedShow a devlink port of the subfunction:
$ 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 state inactive opstate detachedDelete a devlink port of subfunction after use:
$ devlink port del pci/0000:06:00.0/32768
Function attributes¶
The mlx5 driver provides a mechanism to setup PCI VF/SF function attributes in a unified way for SmartNIC and non-SmartNIC.
This is supported only when the eswitch mode is set to switchdev. Port function configuration of the PCI VF/SF is supported through devlink eswitch port.
Port function attributes should be set before PCI VF/SF is enumerated by the driver.
MAC address setup¶
mlx5 driver support devlink port function attr mechanism to setup MAC address. (refer to Devlink Port)
RoCE capability setup¶
Not all mlx5 PCI devices/SFs require RoCE capability.
When RoCE capability is disabled, it saves 1 Mbytes worth of system memory per PCI devices/SF.
mlx5 driver support devlink port function attr mechanism to setup RoCE capability. (refer to Devlink Port)
migratable capability setup¶
User who wants mlx5 PCI VFs to be able to perform live migration need to explicitly enable the VF migratable capability.
mlx5 driver support devlink port function attr mechanism to setup migratable capability. (refer to Devlink Port)
IPsec crypto capability setup¶
User who wants mlx5 PCI VFs to be able to perform IPsec crypto offloading need to explicitly enable the VF ipsec_crypto capability. Enabling IPsec capability for VFs is supported starting with ConnectX6dx devices and above. When a VF has IPsec capability enabled, any IPsec offloading is blocked on the PF.
mlx5 driver support devlink port function attr mechanism to setup ipsec_crypto capability. (refer to Devlink Port)
IPsec packet capability setup¶
User who wants mlx5 PCI VFs to be able to perform IPsec packet offloading need to explicitly enable the VF ipsec_packet capability. Enabling IPsec capability for VFs is supported starting with ConnectX6dx devices and above. When a VF has IPsec capability enabled, any IPsec offloading is blocked on the PF.
mlx5 driver support devlink port function attr mechanism to setup ipsec_packet capability. (refer to Devlink Port)
SF state setup¶
To use the SF, the user must activate the SF using the SF function state attribute.
Get the state of the SF identified by its unique devlink port index:
$ devlink port show ens2f0npf0sf88 pci/0000:06:00.0/32768: type eth netdev ens2f0npf0sf88 flavour pcisf controller 0 pfnum 0 sfnum 88 external false splittable false function: hw_addr 00:00:00:00:88:88 state inactive opstate detachedActivate the function and verify its state is active:
$ devlink port function set ens2f0npf0sf88 state active $ devlink port show ens2f0npf0sf88 pci/0000:06:00.0/32768: type eth netdev ens2f0npf0sf88 flavour pcisf controller 0 pfnum 0 sfnum 88 external false splittable false function: hw_addr 00:00:00:00:88:88 state active opstate detached
Upon function activation, the PF driver instance gets the event from the device that a particular SF was activated. It’s the cue to put the device on bus, probe it and instantiate the devlink instance and class specific auxiliary devices for it.
Show the auxiliary device and port of the subfunction:
$ devlink dev show devlink dev show auxiliary/mlx5_core.sf.4 $ devlink port show auxiliary/mlx5_core.sf.4/1 auxiliary/mlx5_core.sf.4/1: type eth netdev p0sf88 flavour virtual port 0 splittable false $ rdma link show mlx5_0/1 link mlx5_0/1 state ACTIVE physical_state LINK_UP netdev p0sf88 $ rdma dev show 8: rocep6s0f1: node_type ca fw 16.29.0550 node_guid 248a:0703:00b3:d113 sys_image_guid 248a:0703:00b3:d112 13: mlx5_0: node_type ca fw 16.29.0550 node_guid 0000:00ff:fe00:8888 sys_image_guid 248a:0703:00b3:d112
Subfunction auxiliary device and class device hierarchy:
mlx5_core.sf.4 (subfunction auxiliary device) /\ / \ / \ / \ / \ mlx5_core.eth.4 mlx5_core.rdma.4 (sf eth aux dev) (sf rdma aux dev) | | | | p0sf88 mlx5_0 (sf netdev) (sf rdma device)
Additionally, the SF port also gets the event when the driver attaches to the auxiliary device of the subfunction. This results in changing the operational state of the function. This provides visibility to the user to decide when is it safe to delete the SF port for graceful termination of the subfunction.
Show the SF port operational state:
$ devlink port show ens2f0npf0sf88 pci/0000:06:00.0/32768: type eth netdev ens2f0npf0sf88 flavour pcisf controller 0 pfnum 0 sfnum 88 external false splittable false function: hw_addr 00:00:00:00:88:88 state active opstate attached