Re: Better systemd naming for Azure/MANA nic

 

Hi Dimitri,

 

During the meeting a few months ago, you mentioned we cannot set “net.if_name=0” due to impact of other device naming... We have recently fixed the Physical slot number of MANA NICs, could you change the naming scheme as discussed last time?

 

Currently the domain number is part of the name (and Physical Slot + dev_port), e.g. enP30832s1, enP30832s1d1, enP30832s1d2… But domain number is long, and may not be the same on different VMs.

 

As discussed previously, we prefer a short name based on the VF “Physical Slot” + dev_port.

For VF the Physical Slot starts from 1, and increment by 1 for each additional VF device. (PF nic doesn’t have the Physical Slot number, so you can continue to use “0” there).

The dev_port starts from 0, and increment by 1 for each additional dev_port (NIC).

 

Here is the logic we hope to have in the systemd: If a NIC’s driver is “mana”, use this naming scheme:

<prefix><Physical Slot>d<dev_port>   //During the meeting, we briefly talked about the prefix can be “enm” (enthernet, mana), so the names of two VF devices with 3 dev_ports (NICs) each, can be:   enm1  // omits the dev_port number if it’s 0. enm1d1 enm1d2   enm2 enm2d1 enm2d2

 

 

Here is the Physical Slot, dev_port info from a running VM:

root@lisa--500-e0-n1:/sys/class/net# lspci -v -s7870:00:00.0

7870:00:00.0 Ethernet controller: Microsoft Corporation Device 00ba

        Subsystem: Microsoft Corporation Device 00b9

        Physical Slot: 1

        Flags: bus master, fast devsel, latency 0, NUMA node 0

        Memory at fc2000000 (64-bit, prefetchable) [size=32M]

        Memory at fc4000000 (64-bit, prefetchable) [size=32K]

        Capabilities: [70] Express Endpoint, MSI 00

        Capabilities: [b0] MSI-X: Enable+ Count=1024 Masked-

        Capabilities: [100] Alternative Routing-ID Interpretation (ARI)

        Kernel driver in use: mana

 

root@lisa--500-e0-n1:/sys/class/net# grep "" en*/dev_port

enP30832s1/dev_port:0

enP30832s1d1/dev_port:1

enP30832s1d2/dev_port:2

 

Thanks,

• Haiyang