On Thu, Sep 13, 2018 at 12:05:27PM -0500, Steve Wise wrote: > > > 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... I think we have to do this to get the proper command line interface.. Otherwise in userspace you have to parse the kind and send a unique per driver message.. Jason
