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

[David Ahern <dsahern@gmail.com>]

On 04/25/11 11:30, Alex Williamson wrote:
> # modprobe -r igbvf
> # ip link set eth2 vf 6 mac 02:00:10:91:73:01
> # modprobe igbvf
> # dmesg | grep "igbvf 0000\:01\:11.5\: Address\:"
> igbvf 0000:01:11.5: Address: d2:c8:17:d6:97:f7
> igbvf 0000:01:11.5: Address: 4e:ee:2a:d8:12:7c
> igbvf 0000:01:11.5: Address: 02:00:10:91:73:01
> # modprobe -r igbvf
> # echo 1 > /sys/bus/pci/devices/0000:01:11.5/reset
> # modprobe igbvf
> # dmesg | grep "igbvf 0000\:01\:11.5\: Address\:"
> igbvf 0000:01:11.5: Address: d2:c8:17:d6:97:f7
> igbvf 0000:01:11.5: Address: 4e:ee:2a:d8:12:7c
> igbvf 0000:01:11.5: Address: 02:00:10:91:73:01
> igbvf 0000:01:11.5: Address: 02:00:10:91:73:01
> 
> So now it sticks.  You're going to get random mac addresses on the VFs
> every time you reload the igb driver (ie. ever boot) anyway (at least
> with these sr-iov cards), so if you need consistent macs, they probably
> need to be set before launching the VM anyway.  Thanks,
> 
> Alex
> 

Ok, I was able to repeat the above commands from the host command line.

However, when qemu-kvm starts the MAC is reset.

# ip link show | less

2: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP
qlen 1000
    link/ether 00:1b:21:98:b7:10 brd ff:ff:ff:ff:ff:ff
    vf 0 MAC 02:12:34:56:80:20

--> that's the MAC address I set

I start qemu-kvm (unpatched version) and the host side sees the address
changed:

# ip link show | less

2: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP
qlen 1000
    link/ether 00:1b:21:98:b7:10 brd ff:ff:ff:ff:ff:ff
    vf 0 MAC 7a:17:3f:98:0f:db


Can you try that aspect on your end - seeing if the MAC address
maintains after starting qemu-kvm?

David