On 7/25/2018 2:05 PM, Jason Gunthorpe wrote: > On Mon, Jul 16, 2018 at 02:07:57PM -0500, Steve Wise wrote: >> >> >> On 3/1/2018 11:18 AM, Jason Gunthorpe wrote: >>> On Thu, Mar 01, 2018 at 10:28:00AM -0600, Steve Wise wrote: >>>>> On Thu, Mar 01, 2018 at 09:29:04AM -0600, Steve Wise wrote: >>>>> >>>>>> Maybe to add a network interface to a soft-rdma device like rxe, we >>>> could >>>>> create a syntax like this: >>>>>> rdma link set rxe_eth0 dev eth0 >>>>> More like: >>>>> >>>>> rdma link add rxe_eth0 type rxe dev eth0 >>>>> >>>>> 'type rxe' triggers the kernel to dispatch to the rxe or siw driver to >>>>> create the interface. >>>> Type doesn't sound right though. in the current rdma synax, it would be >>>> 'dev'. Maybe: >>>> >>>> rdma link add rxe_eth0 dev rxe netdev eth0 >>> Type is the consistent tag with 'ip link add'. >> >> Hey guys, >> >> I'm starting to think about how to implement 'rdma link add/delete' for >> rxe. Does it make sense to add new members to the rdma_nldev_command >> enum in include/uapi/rdma/rdma_netlink.h for adding and deleting >> soft-rdma links to netdev interfaces? Something like >> RDMA_NLDEV_CMD_LINK_ADD and RDMA_NLDEV_CMD_LINK_DEL? Then add handlers >> to the nldev_cb_table array in drivers/infiniband/core/nldev.c. Can >> we assume there is only one soft-rdma driver for each rdma transport? >> That would enable a simple core->driver dispatch via an array of >> driver-specific handler functions that are indexed by the soft-rdma >> transport type. Or do we need something more general? >> >> Just thinking out loud here. What do you all think? > > You may as well follow the pattern ip link add uses.. > > See struct rtnl_link_ops ipoib_link_ops > > This way we can keep rxe as a module without creating a link time > dependency on the core module. > > Core code should match the 'type' tag with the '.kind' string member > just as ip does, and should pas a netlink attrs bundle in to the callback > like ip, see ipoib_new_child_link() > > The result should return the rdma id and name of the newly created > interface. > Should the rxe driver just register with an actual rtnl_link_ops? And use that rtnl core facility to dispatch callbacks? Or should we create a similar rdma_link_ops struct that includes the '.kind' and other appropriate fields, and have our own dispatcher in drivers/infiniband/core? Seems like we could simplify it some some... Steve.
