Re: [libvirt] interface "peer address" patches are broken

I haven't had the time to fix it yet, but wanted to point out that the patches that are supposed to support setting the peer address of tap/macvlan devices do not work. The problem is that the peer attribute isn't being included when the XML for a a domain interface is being formatted. I also sent the following message last week as a followup to the patch series; possibly it wasn't noticed for that reason:. I'll make a patch to fix the formatting when I can so that I can test my theory about address vs. peer on lxc vs qemu. But if it's fixed by someone else in the meantime, all the better :-) On 04/20/2016 12:36 PM, Laine Stump wrote: > Something I've found myself worrying about lately while driving in the > car or nodding off to sleep - are the "address" and "peer" attributes > effectively used in the same way for all network connection types and both > hypervisors? I think the answer may be "no", and if so we need to fix that > before they go out in a release. > > In particular, when an lxc domain's interface has: > > <ip address='192.168.128.1'/> > > That is the IP address seen by the guest, not the host. So I would assume > that if an LXC domain had: > > > <ip address='192.168.128.1' peer='192.168.128.2'/> > > that 192.168.128.1 would still be the IP address see by the guest, and > 192.168.128.2 would be the IP address on the host side; and it should be > the same for qemu. > > From what I can see of the code, though, on a qemu domain, the IP address > is set for the tap device's own IP, meaning that it would show up on the > *host* side, while the peer address would be what the host expects to be at > the other end of the tap device (i.e. the guest side), so the two > attributes are used for the *opposite* end of the PTP link in lxc vs. qemu. > > I think that, instead, the "address" attribute should *always* be the IP > address that is seen/used by the guest, and the "peer" attribute should be > the IP address that is seen/used by the host. (perhaps "peer" could be > replaced with some other name, like "host" or "hostAddress" to avoid > confusion? (don't like either of those alternatives, but I don't really > like peer either)). > > Aside from that, I can see that these patches have been pushed in the > code that I'm running, and I've been trying to add "peer='blah'" to > interface IP addresses on my test machine, but it's just removed from the > config. Have you tested what got pushed? Has something gone wrong? > > Since there hasn't been a release with these patches included yet, there > is still time to fix it at least to be consistent (assuming that my > suspicions are correct; I've been unable to test it myself for the reason > above). >