On Tue, 2015-05-26 at 10:59 -0600, Jason Gunthorpe wrote: > On Tue, May 26, 2015 at 09:34:40AM -0400, Doug Ledford wrote: > > > This is a core feature more than anything else. Namespaces for RDMA > > devices is not unique to IB or RoCE in any way. Yet no thought has been > > given to how this will work universally across all of the RDMA > > capable > > I think if Haggi is able to follow the perscription I gave then things > will be general. > > - All rdma cm ids are associated with a netdev > - The output flow uses that netdev to restrict, configure and > determine the output RDMA device QP > - The input flow locates the netdev as step one and then uses the > (netdev,ip,port) tuple to find the rdma listener, which is in turn > tied to a netdev and is restricted/configured by it. > > The technology specific part is the two maps: from (input > device,packet) to netdev, from netdev to (output device,packet) > > After the above clean up is done, namespace enabling is basically > providing those two mapping functions for each technology in a way > that can locate delegatable netdevs. > > The trivial case for all the ethernet techs is to provide the above > maps that can take the (input device,VLAN) and locate the correct > child VLAN specific netdev. The existing code to support VLAN should > pretty much immediately enable basic namespace support for all the > ethernet families. > > The big open question for ethernet is how to work without relying on > VLAN to create delgated netdevs - typically one would use a bridge and > veth's, which do not seem very RDMA compatible. But that doesn't need > to be answered right now. > > Remember, this isn't RDMA namespaces, this is netdev namespace support > for RDMA-CM -> very different things.
That was the point of my email. This is a very myopic view of the feature. It *should* at least have an idea of these other things too. > Basically, I'm happy with the generality story, if the clean up work I > outlined turns out.. > > > issue for usNIC as if you want namespace support there, you just start > > the user space app in a given namespace and you are probably 90% of > > the > > usNIC has no kernel facing functionality, and no interaction with > RDMA-CM, so it is irrelevant to any discussion about RDMA-CM :( Whether usNIC has a kernel facing functionality or not is irrelevant. This feature isn't kernel only, it effects user space applications launched in a namespace too. And, again, my point was that this discussion is about RDMA-CM and it should be broader (even if the implementation isn't broader). Due to the implementation of usNIC I suspect it would "just work", but it would be better to know so. -- Doug Ledford <dledf...@redhat.com> GPG KeyID: 0E572FDD
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