Merge branch 'devlink-mlx5-add-port-function-attributes-for-ipsec'

Merge branch 'devlink-mlx5-add-port-function-attributes-for-ipsec'

Saeed Mahameed says:

====================
{devlink,mlx5}: Add port function attributes for ipsec

From Dima:

Introduce hypervisor-level control knobs to set the functionality of PCI
VF devices passed through to guests. The administrator of a hypervisor
host may choose to change the settings of a port function from the
defaults configured by the device firmware.

The software stack has two types of IPsec offload - crypto and packet.
Specifically, the ip xfrm command has sub-commands for "state" and
"policy" that have an "offload" parameter. With ip xfrm state, both
crypto and packet offload types are supported, while ip xfrm policy can
only be offloaded in packet mode.

The series introduces two new boolean attributes of a port function:
ipsec_crypto and ipsec_packet. The goal is to provide a similar level of
granularity for controlling VF IPsec offload capabilities, which would
be aligned with the software model. This will allow users to decide if
they want both types of offload enabled for a VF, just one of them, or
none at all (which is the default).

At a high level, the difference between the two knobs is that with
ipsec_crypto, only XFRM state can be offloaded. Specifically, only the
crypto operation (Encrypt/Decrypt) is offloaded. With ipsec_packet, both
XFRM state and policy can be offloaded. Furthermore, in addition to
crypto operation offload, IPsec encapsulation is also offloaded. For
XFRM state, choosing between crypto and packet offload types is
possible. From the HW perspective, different resources may be required
for each offload type.

Examples of when a user prefers to enable IPsec packet offload for a VF
when using switchdev mode:

  $ devlink port show pci/0000:06:00.0/1
      pci/0000:06:00.0/1: type eth netdev enp6s0pf0vf0 flavour pcivf pfnum 0 vfnum 0
          function:
          hw_addr 00:00:00:00:00:00 roce enable migratable disable ipsec_crypto disable ipsec_packet disable

  $ devlink port function set pci/0000:06:00.0/1 ipsec_packet enable

  $ devlink port show pci/0000:06:00.0/1
      pci/0000:06:00.0/1: type eth netdev enp6s0pf0vf0 flavour pcivf pfnum 0 vfnum 0
          function:
          hw_addr 00:00:00:00:00:00 roce enable migratable disable ipsec_crypto disable ipsec_packet enable

This enables the corresponding IPsec capability of the function before
it's enumerated, so when the driver reads the capability from the device
firmware, it is enabled. The driver is then able to configure
corresponding features and ops of the VF net device to support IPsec
state and policy offloading.

v2: https://lore.kernel.org/netdev/20230421104901.897946-1-dchumak@nvidia.com/
====================

Link: https://lore.kernel.org/r/20230825062836.103744-1-saeed@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>