On Wed, Sep 26, 2018 at 10:44:56AM -0500, Steve Wise wrote:
>
>
> On 9/26/2018 3:05 AM, Leon Romanovsky wrote:
> > On Tue, Sep 25, 2018 at 02:11:18PM -0600, Jason Gunthorpe wrote:
> >> On Tue, Sep 25, 2018 at 08:55:29PM +0300, Leon Romanovsky wrote:
> >>> On Thu, Sep 13, 2018 at 12:16:20PM -0700, Steve Wise wrote:
> >>>> Add support for new LINK messages to allow adding and deleting rdma
> >>>> interfaces. This will be used initially for soft rdma drivers which
> >>>> instantiate device instances dynamically by the admin specifying a netdev
> >>>> device to use. The rdma_rxe module will be the first user of these
> >>>> messages.
> >>>>
> >>>> The design is modeled after RTNL_NEWLINK/DELLINK: rdma drivers
> >>>> register with the rdma core if they provide link add/delete functions.
> >>>> Each driver registers with a unique "type" string, that is used to
> >>>> dispatch messages coming from user space. A new RDMA_NLDEV_ATTR is
> >>>> defined for the "type" string. User mode will pass 3 attributes in a
> >>>> NEWLINK message: RDMA_NLDEV_ATTR_IBDEV_NAME for the desired rdma device
> >>>> name to be created, RDMA_NLDEV_ATTR_LINK_TYPE for the "type" of link
> >>>> being added, and RDMA_NLDEV_ATTR_NDEV_NAME for the net_device interface
> >>>> to use for this link. The DELLINK message will contain the IBDEV_NAME
> >>>> and LINK_TYPE attributes.
> >>>>
> >>>> Signed-off-by: Steve Wise <swise@xxxxxxxxxxxxxxxxxxxxx>
> >>>
> >>> <...>
> >>>>
> >>>> + RDMA_NLDEV_CMD_NEWLINK,
> >>>> +
> >>>> + RDMA_NLDEV_CMD_DELLINK,
> >>>> +
> >>>> RDMA_NLDEV_NUM_OPS
> >>>> };
> >>>>
> >>>> @@ -427,6 +431,11 @@ enum rdma_nldev_attr {
> >>>> RDMA_NLDEV_ATTR_DRIVER_U64, /* u64 */
> >>>>
> >>>> /*
> >>>> + * Identifies the rdma driver. eg: "rxe" or "siw"
> >>>> + */
> >>>> + RDMA_NLDEV_ATTR_LINK_TYPE, /* string */
> >>>
> >>> I'll review it more deeply tomorrow, but two things caught my attention:
> >>> 1. You need RDMA_NL_ADMIN_PERM for your netlink commands
> >>> 2. LINK_TYPE should be index and not string, because it is why we are
> >>> using using netlink :)
> >>
> >> netdev uses strings. See IFLA_INFO_KIND
> >>
> >> strings are not bad in netlink
> >
> > It is not the best example, because IFLA_INFO_KIND is used to forward
> > filtering information and one day we will do the same with various
> > rdmatool dumping options. However in case of ibdevice type, it is
> > declared as number and doesn't seem to me right to convert it to string
> > and limit our KABI to name.
> >
>
> Are you suggesting rdmatool uses enum rdma_driver_id from
> rdma/rdma_user_ioctl_cmds.h? So I add code in rdmatool to map the
> user's string, eg "mlx5" or "rxe" into the enum and send that down?
>
> That works for me. If rdma_driver_id is part of the KABI, then I guess
> its fine for rdmatool to use it and map names to enum values...
I think so, for me it sounds like a good thing. I'll reuse this enum
rdma_driver_id in rdma-core later on.
Thanks
>
> Steve.
>
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