Passing through a single Ethernet port while using the second for Unraid

[majo23]

HI, 

sry for beeing stupid, but all tutroials and posts are talking about using a networkcard or passing through ALL onboard Ports...

but i only need to passthrough a single one (of my two ports) to a vm.

I have a Asus P8B-M which has 2 Ethernet ports. One is in use for unraid the other one isn`t in use and i want to pass it through to VMs....

I managed to get them in separate IOMMU Groups but what now?

 

Using append vfio-pci.ids=8086:10d3 would mean unraid loses both, right? So this would be quite bad^^ How to make only one free?

 

 

 

Here is my network config for port 2 (eth1) that i want to passthrough....

i tried to "Port Down" it, but didnt helped...

 

Maybe changing the VM XML? But i have no clue where to start, guides always refer to Networkcards but not to a single onBoardPort....

 <interface type='bridge'>
      <mac address='52:54:00:3f:fd:d9'/>
      <source bridge='br1'/>
      <model type='e1000'/>
      <address type='pci' domain='0x0000' bus='0x06' slot='0x01' function='0x0'/>
    </interface>

any ideas?

 

Edited October 15, 2021 by majo23

[ghost82]

12 hours ago, majo23 said:

One is in use for unraid the other one isn`t in use

The other one IS in use (I assume ethernet at 5:00.0 is eth1).

Any reason you are trying to passthrough the ethernet?Could you consider using the virtual bridged network br1 (the xml snippet does so..)?

So either passthrough the ethernet by attaching to vfio, or use a bridge: the difference is the vm in the first case will see the real ethernet card, in the other case it will create a virtual controller that will use the bridge connectivity.

 

Passthrough case:

Quote

Using append vfio-pci.ids=8086:10d3 would mean unraid loses both, right?

 

Correct, but starting from unraid 6.9, the setup in System devices page will bind the device both on vendor/device ids and domain:bus:slot.function, so in your case it will be setup like:

BIND=0000:05:00.0|8086:10d3

 

The issue here is that the ethernet will always be grabbed by unraid even if it's inactive.

And apparently you cannot isolate from the gui.

If I were you I woud:

1. backup the unraid usb, so to restore if something goes wrong

2. open config/vfio-pci.cfg with a text editor in the unraid usb stick

3. Add BIND=0000:05:00.0|8086:10d3

If you have multiple devices isolated just append them, for example:

BIND=0000:05:00.0|8086:10d3 0000:04:00.0|10de:100c 0000:04:00.1|10de:0e1a

 

Save and reboot, and your eth1 should now be isolated, without loosing eth0 connectivity for unraid.

Edited October 16, 2021 by ghost82