[ovs-dev] [PATCH] datapath: compat: fix kernel module reference count.

[William Tu]

>> After the dpif-netlink-rtnl, a tunnel device can be created by using
>> rtnetlink, so the creation of fb device comes from the ovs-vswitchd
>> instead of going through OVS kernel modules.  This breaks the module
>> dependency between 1) and 2).  As a result, when ovs-vswitchd is running,
>> the 'lsmod' shows:
>>   geneve                 27326  1 vport_geneve
>>   vport_geneve           12560  0
>>   openvswitch           172469  1 vport_geneve
>
> Which is correct. vport_geneve is not using geneve. If anything is using

Actually vport_geneve is using geneve. (Please correct me if I'm wrong)
If we're using upstream tunnel (USE_UPSTREAM_TUNNEL=yes)
then vport_geneve calls into kernel's geneve_dev_create_fb(), so it
has symbol dependency.
If USE_UPSTREAM_TUNNEL=no, then geneve_dev_create_fb is replaced with rpl_xxx,
then no dependency.

Can we say that if (OVS version == 2.8 && USE_UPSTREAM_TUNNEL=yes),
then we don't need any vport-xxx implementation and we can remove these code?

Thanks
William

> geneve, it's vport_netdev. But it already provides the proper linkage
> via netdev_master_upper_dev_link().
>