TX/RX statistics need to be swapped

[Oleg Vasilev]

Hi,

virDomainNetTypeSharesHostView[1] contains the logic where for some 
interface types it swaps TX and RX values, because what TX from the 
inside is RX on the outside and vice versa.

We observe a configuration where <interface type='ethernet' /> shows 
swapped values in statistics, because, apparently, the values are 
swapped once inside the kernel when going from the inside to the 
outside, but not swapped second time because of the mentioned logic.

Is this a bug? Why in the virDomainNetTypeSharesHostView[1] ethernet is 
marked as 'non-swapped'?

Maybe we need some more fine-grained way of determining whether to swap 
value a second time?

Thanks,
Oleg

[1]: 
https://gitlab.com/libvirt/libvirt/-/blob/master/src/conf/domain_conf.c#L29092