On Wed, Oct 7, 2015 at 1:09 AM, Jiri Benc <jb...@redhat.com> wrote: > On Tue, 6 Oct 2015 14:16:02 -0700, Pravin Shelar wrote: >> When OVS needs to add a vxlan tunnel device, OVS can create the vxlan >> device and check the parameters for the flag. If the flag does not >> exist then fallback to vport-create. > > You omitted the very important step, delete the device before falling > back. > > This means that with older kernels, there will be an interface created > and destroyed shortly after. With all netlink notifications sent, all > tools listening for netlink events seeing the interface appear and go, > with this being logged in various places, etc. Sounds very hacky and > confusing to anyone watching their logs or output of such tools. That > is the confusion I was talking about. > >> This only needs to be done for >> very first tunnel device. Thats how most of features are supported in >> OVS. > > The big difference to the other features is this cannot be detected > until half way through the setup. > > What I'm proposing instead is to introduce a way to clearly and > unambiguously detect whether lwtunnels are supported or not. We'll need > this anyway: kernel 4.3 won't really support IPv6 tunneling with ovs, > yet there's currently no way to determine whether it's supported or not > (and, unlike with lwtunnel detection, there's not even a hacky way). > Querying the datapath for the supported features is needed > nevertheless; it's only logical to use it for the lwtunnel vs. old > vport decision, too. > > I don't understand why you're opposed to this: it's much cleaner and > there's no problem with lwtunnels not being used with the 4.3 kernel, > everything should work just fine. >
I don't want to add more flags to OVS for features which can be derived from other APIs. But if creating and destroying single virtual device is such big deal then I am fine with the alternative approach. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
