[SR-IOV]: Use static MAC addresses with udev rules for renaming VF interfaces (Mellanox CX4) (Documentation)

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Problem Description
=============
The udev rules for renaming the SR-IOV Mellanox CX4 VF interface are not getting
implemented. After setting the udev rules, and unbind/bind the drivers for the VF's,
the interface name still doesn't change. Same issue isn't noticed for the PF of the
SR-IOV adapter.

Resolution
=======
Use static MAC addresses for renaming SRIOV Mellanox CX4 VF interfaces with udev rules.

Documentation
==========
With Mellanox CX4 SR-IOV when the VFs are created, each of them will get a random MAC address.
To be able to use the '70-persistent-net.rules' to define interfaces based on MAC Address, one need
to set static MAC address to the VF.

This is an example
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="02:a9:bb:cc:dd:00", NAME="enP4p1s0vf"

First execute below command
echo 02:a9:bb:cc:dd:00 > /sys/class/infiniband/mlx5_0/device/sriov/0/mac

and then
do the unbind/bind
echo 0004:01:00.2 > /sys/bus/pci/drivers/mlx5_core/unbind
echo 0004:01:00.2 > /sys/bus/pci/drivers/mlx5_core/bind

then one can see
enP4p1s0vf: flags=4098<BROADCAST,MULTICAST> mtu 1500
        ether 02:a9:bb:cc:dd:00 txqueuelen 1000 (Ethernet)
        RX packets 0 bytes 0 (0.0 B)
        RX errors 0 dropped 0 overruns 0 frame 0
        TX packets 0 bytes 0 (0.0 B)
        TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2017-05-09 14:14 EDT-------
Hello Canonical,

Please include above documentation text for using static MAC addresses
for renaming SR-IOV Mellanox CX4 VF interfaces with udev rules.

[Gunnar Hjalmarsson (gunnarhj)]

ubuntu-docs is a package for the desktop documentation, and this issue is apparently not related to that. Which set of docs is it you would like to see updated?

[Steve Langasek (vorlon)]

I don't find this request very clear. Several questions:
 - What release are you seeking to have this release noted for? tags suggest 17.04 or 17.10 or both, but neither of these are LTS releases, so I have to question whether the tags are correct.
 - Is the lack of persistent mac addresses a problem with the kernel driver? With the underlying hardware?
 - In what environment should we expect to see this problem? Is it POWER-specific?
 - The workaround suggested appears to be a one-off change, that would still not persist across reboots of the system (or perhaps the state persists within the VM, but would not persist across a cold boot). Have I understood correctly? If so, this does not seem like a complete workaround that warrants recommending to users in the release notes.
 - Why is this being suggested as a release notes change, instead of a request for a fix in the implementation?

[Manoj Iyer (manjo)]

Breno,

Could you please help answer Steve's questions ?

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2017-12-04 11:28 EDT-------
Since we are not seeing update on this bug, and neither I or Carol knows where this bug should go, I am rejecting/closing it.

[Andrew Cloke (andrew-cloke)]

Thanks Breno. I'll close out the LP bug.