On 6/6/19, 10:16 AM, "Jakub Kicinski" <[email protected]> wrote:
Hi Samih!
Please don't top post on Linux kernel mailing lists.
On Thu, 6 Jun 2019 10:23:40 +0000, Jubran, Samih wrote:
> As of today there are no flags exposed by ENA NIC device, however, we
> are planning to use them in the near future. We want to provide
> customers with extra methods to identify (and differentiate) multiple
> network interfaces that can be attached to a single VM. Currently,
> customers can identify a specific network interface (ENI) only by MAC
> address, and later look up this MAC among other multiple ENIs that
> they have. In some cases it might not be convenient. Using these
> flags will let us inform the customer about ENI`s specific
> properties.
Oh no :( You're using private _feature_ flags as labels or tags.
> It's not finalized, but tentatively it can look like this:
> primary-eni: on /* Differentiate between primary and secondary ENIs */
Did you consider using phys_port_name for this use case?
If the intent is to have those interfaces bonded, even better would
be to extend the net_failover module or work on user space ABI for VM
failover. That might be a bigger effort, though.
> has-associated-efa: on /* Will specify ENA device has another associated
EFA device */
IDK how your ENA/EFA thing works, but sounds like something that should
be solved in the device model.
[NB] ENA is a netDev, EFA is an ib_dev. Both share the same physical network
All previous attempt to make them share at device level leads to a lot of
complexity at the OS level, with inter-dependencies that are pronged to error
Not to mention that OS distribution that backport from mainline would backport
different subset of each driver, let alone they belong to two subtrees with
two different maintainers and we don’t want to be in a place where we have to
coordinate releases between two subgroups
As such, we selected a much safer path, that operational, development and
deployment of two different drivers (netdev vs ib_dev) much easier but exposing
the nic as two different Physical functions/devices
Only cost we have is that we need this extra propriety to help user identify
which two devices are related hence Samih's comments
