Re: pci passthrough - VF reset at boot is dropping assigned MAC

[David Ahern <dsahern@gmail.com>]

On 04/25/11 13:18, Alex Williamson wrote:
>>> I don't see this happening on my system, once manually set the mac never
>>> changes.  I can restart and reset the VM and the host and guest both
>>> continue seeing the set mac address.  I tested it with both a recent
>>> rhel6.1 host kernel as well as upstream 2.6.39-rc4.  If I switch to a VF
>>> with an unset mac, those will change on each VM reset or restart.
>>
>> Blacklist igbvf in the host and you will. That must be the difference: I
>> was preventing the vf driver from loading in the host -- it's not needed
>> there, so why load it?
> 
> I already have it blacklisted.  It's not needed if you're using the VFs
> they way we are, but there are other uses.
> 
>> I rebooted for a fresh run. Loaded the igbvf driver before starting the
>> VM using my tools. With the igbvf driver loaded in the host the MAC
>> address for the VF was not reset.
>>
>> As for why I blacklisted it -- udev. What a PITA with VFs. I saw the
>> feature for Fedora 15 which should address this.
> 
> Yes, my VM is up to renaming the VFs eth1340 since the mac changes every
> boot.  I'm still confused though as I did a whole round of testing after
> a reboot where igbvf was never loaded and the set mac address stuck
> across VM restarts and resets.
> 
> Alex
> 

The resetting of the VM MAC address is fixed in 2.6.39-rc4, so it's a
Fedora 14, 2.6.35.12 problem.

David