CFP: add Device convention

[squeed]

After talking with @ajoea, we realized that a convention / capability arg for the runtime to pass devices to CNI plugins would be extremely useful.

The most obvious use-case would be for the result of Kubernetes device plugins to be automatically made available to a CNI plugin. Something like

{
    "capabilities": { "devices": true }
}
// leads to
{
  "runtimeConfig": {
    "devices": [
      {
        "pciID": "0000:00:12.0"
      }
    ]
  }
}

To be determined is merely the format of the information. What do k8s runtimes have available? Do we do the full CDI type?

[squeed]

FYI @aojea, @dougbtv, I would love your input here.

[aojea]

I wrote about it a bit more here opencontainers/runtime-spec#1239, so the kernel identifier for netdevices is the "name", that will be the part we need to pass.

I´m not much into the SRIOV use cases, but afaik the pciID is needed to do some driver binding, I expect that part of configuration/provisioning to be happening before we are in the CNI ADD situation

"devices" is ambigues and is traditionally used for "block devices" , that already has a concept with that name in the OCI spec and in kuberntes, however, we are talking here about "netdevices"

[s1061123]

As containernetworking/plugins#1003, sr-iov case, user may want to specify other way than pciID, such as Auxiliary Bus (see pr 1003 in plugin).

[adrianchiris]

as an FYI : device ID is already defined in CNI conventions

https://github.com/containernetworking/cni/blob/main/CONVENTIONS.md#well-known-capabilities