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author | 2020-12-11 22:12:25 -0800 | |
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committer | 2021-01-22 11:32:12 -0800 | |
commit | 142d93d12dc187f6a32aae2048da0c8230636b86 (patch) | |
tree | 1c46a93e420374f3c2e97529fefe7ae829c14f13 /Documentation | |
parent | devlink: Extend devlink port documentation for subfunctions (diff) | |
download | linux-142d93d12dc187f6a32aae2048da0c8230636b86.tar.gz linux-142d93d12dc187f6a32aae2048da0c8230636b86.tar.bz2 linux-142d93d12dc187f6a32aae2048da0c8230636b86.zip |
net/mlx5: Add devlink subfunction port documentation
Add documentation for subfunction management using devlink
port.
Signed-off-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/networking/device_drivers/ethernet/mellanox/mlx5.rst | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/Documentation/networking/device_drivers/ethernet/mellanox/mlx5.rst b/Documentation/networking/device_drivers/ethernet/mellanox/mlx5.rst index a5eb22793bb9..a1b32fcd0d76 100644 --- a/Documentation/networking/device_drivers/ethernet/mellanox/mlx5.rst +++ b/Documentation/networking/device_drivers/ethernet/mellanox/mlx5.rst @@ -12,6 +12,8 @@ Contents - `Enabling the driver and kconfig options`_ - `Devlink info`_ - `Devlink parameters`_ +- `mlx5 subfunction`_ +- `mlx5 port function`_ - `Devlink health reporters`_ - `mlx5 tracepoints`_ @@ -181,6 +183,214 @@ User command examples: values: cmode driverinit value true +mlx5 subfunction +================ +mlx5 supports subfunction management using devlink port (see :ref:`Documentation/networking/devlink/devlink-port.rst <devlink_port>`) 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 ther 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/deactive 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 flaovur:: + + $ 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 detached + +- Show 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 detached + +- Delete a devlink port of subfunction after use:: + + $ devlink port del pci/0000:06:00.0/32768 + +mlx5 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 provides mechanism to setup the MAC address of the PCI VF/SF. + +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 VF 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 pcivf pfnum 0 sfnum 88 + function: + hw_addr 00:00:00:00:88:88 + +SF state setup +-------------- +To use the SF, the user must active 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 detached + +- Activate 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 visiblity 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 + Devlink health reporters ======================== |