Multicast promiscuous mode is unset on VF when VM is launched

Issue

• We are having and issue receiving IPv6 multicast packets on our VM. We would like to set unicast and multicast promiscuous mode on the VFs associated with our VM. How can we do this?

• This used to work in RHOSP10 but fails with RHOSP13.

• Before VM start up:

[root@overcloud-compute-3 ~]# ip link show ens1f0
5: ens1f0: <BROADCAST,MULTICAST,ALLMULTI,PROMISC,UP,LOWER_UP> mtu 9000 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 00:00:00:00:00:e8 brd ff:ff:ff:ff:ff:ff
    vf 0 MAC 00:00:00:00:00:00, spoof checking off, link-state auto, trust on
    vf 1 MAC 00:00:00:00:00:00, spoof checking on, link-state auto, trust on
    vf 2 MAC 00:00:00:00:00:00, spoof checking on, link-state auto, trust on
    vf 3 MAC 00:00:00:00:00:00, spoof checking on, link-state auto, trust on
    vf 4 MAC 00:00:00:00:00:00, spoof checking on, link-state auto, trust on
    vf 5 MAC 00:00:00:00:00:00, spoof checking on, link-state auto, trust on
    vf 6 MAC 00:00:00:00:00:3e, spoof checking on, link-state auto, trust on
    vf 7 MAC 00:00:00:00:00:58, spoof checking on, link-state auto, trust on
[root@overcloud-compute-3 ~]# ip link show  enp18s2f6
126: enp18s2f6: <BROADCAST,MULTICAST,ALLMULTI,PROMISC,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 00:00:00:00:00:3e brd ff:ff:ff:ff:ff:ff
[root@overcloud-compute-3 ~]# ip link show  enp18s2f7
127: enp18s2f7: <BROADCAST,MULTICAST,ALLMULTI,PROMISC,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 00:00:00:00:00:58 brd ff:ff:ff:ff:ff:ff

• We can see the following in the log:

Apr 22 10:49:04 overcloud-compute-3 kernel: device enp18s2f6 entered promiscuous mode
Apr 22 10:49:06 overcloud-compute-3 kernel: iavf 0000:12:02.6: Entering promiscuous mode
Apr 22 10:49:06 overcloud-compute-3 kernel: iavf 0000:12:02.6: Entering multicast promiscuous mode
Apr 22 10:49:06 overcloud-compute-3 kernel: i40e 0000:12:00.0: VF 6 successfully set multicast promiscuous mode
Apr 22 10:49:06 overcloud-compute-3 kernel: i40e 0000:12:00.0: VF 6 successfully set unicast promiscuous mode
Apr 22 10:49:23 overcloud-compute-3 kernel: device enp18s2f7 entered promiscuous mode
Apr 22 10:49:24 overcloud-compute-3 kernel: iavf 0000:12:02.7: Entering promiscuous mode
Apr 22 10:49:24 overcloud-compute-3 kernel: iavf 0000:12:02.7: Entering multicast promiscuous mode
Apr 22 10:49:24 overcloud-compute-3 kernel: i40e 0000:12:00.0: VF 7 successfully set multicast promiscuous mode
Apr 22 10:49:24 overcloud-compute-3 kernel: i40e 0000:12:00.0: VF 7 successfully set unicast promiscuous mode

• After VM start up, enp18s2f6 and enp18s2f7 disappear:

[root@overcloud-compute-3 ~]# ip link show ens1f0
5: ens1f0: <BROADCAST,MULTICAST,ALLMULTI,PROMISC,UP,LOWER_UP> mtu 9000 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 00:00:00:00:00:e8 brd ff:ff:ff:ff:ff:ff
    vf 0 MAC 00:00:00:00:00:00, spoof checking off, link-state auto, trust on
    vf 1 MAC 00:00:00:00:00:00, spoof checking on, link-state auto, trust on
    vf 2 MAC 00:00:00:00:00:00, spoof checking on, link-state auto, trust on
    vf 3 MAC 00:00:00:00:00:00, spoof checking on, link-state auto, trust on
    vf 4 MAC 00:00:00:00:00:00, spoof checking on, link-state auto, trust on
    vf 5 MAC 00:00:00:00:00:00, spoof checking on, link-state auto, trust on
    vf 6 MAC 00:00:00:00:00:a6, vlan 471, spoof checking on, link-state auto, trust on
    vf 7 MAC 00:00:00:00:00:6d, vlan 473, spoof checking on, link-state auto, trust on

• We can see the following in the log:

Apr 22 10:55:19 overcloud-compute-3 kernel: i40e 0000:12:00.0: VF 7 successfully unset multicast promiscuous mode
Apr 22 10:55:19 overcloud-compute-3 kernel: i40e 0000:12:00.0: VF 7 successfully set unicast promiscuous mode
Apr 22 10:55:20 overcloud-compute-3 kernel: i40e 0000:12:00.0: VF 6 successfully unset multicast promiscuous mode
Apr 22 10:55:20 overcloud-compute-3 kernel: i40e 0000:12:00.0: VF 6 successfully set unicast promiscuous mode