On Fri, 26 Jan 2018 21:33:01 -0800, Samudrala, Sridhar wrote: > >> 3 netdev model breaks this configuration starting with the creation > >> and naming of the 2 devices to udev needing to be aware of master and > >> slave virtio-net devices. > > I don't understand this comment. There is one virtio-net device and > > one "virtio-bond" netdev. And user space has to be aware of the special > > automatic arrangement anyway, because it can't touch the VF. It > > doesn't make any difference whether it ignores the VF or PV and VF. > > It simply can't touch the slaves, no matter how many there are. > > If the userspace is not expected to touch the slaves, then why do we need to > take extra effort to expose a netdev that is just not really useful.
You said: "[user space] needs to be aware of master and slave virtio-net devices." I'm saying: It has to be aware of the special arrangement whether there is an explicit bond netdev or not. > >> Also, from a user experience point of view, loading a virtio-net with > >> BACKUP feature enabled will now show 2 virtio-net netdevs. > > One virtio-net and one virtio-bond, which represents what's happening. > This again assumes that we want to represent a bond setup. Can't we > treat this > as virtio-net providing an alternate low-latency datapath by taking over > VF datapath? Bond is just a familiar name, we can call it something else if you prefer. The point is there are two data paths which can have independent low-level settings and a higher level entity with global settings which represents any path to the outside world. Hiding low-level netdevs from a lay user requires a generic solution.
