[openib-general] multicast code/merge status

[Or Gerlitz]

Sean Hefty wrote:
>> OK, got you at last (sorry but i have somehow ignored the call to
>> ib_addr_get_mgid() at the rdmacm code). So to achieve interop with
>> IPoIB all we need to do is remove the rdmacm signature bit and not to
>> over-write the rdmacm qkey on the the qkey of the ipoib ipv4 broadcast
>> group, are you ok with that?

> I believe this would achieve interop with ipoib.  However, overwriting 
> the qkey may break any existing UD communication that the user may 
> have.  I just need to think about this more, and see what we can come up 
> with.

Hi Sean,

Based on our communication so far, the elements which are missing are

++ on the rdmacm kernel code: (drivers/infiniband/core/cma.c)

+1 remove the rdmacm signature byte from the mgid
+2 get the qkey used by the ipv4 broadcast group and use it

mimic IPoIB qkey flow:

+3 on rdma_create_qp do modify qp with some def qkey (eg zero)
+4 on the join completion path before attaching a qp to the associated
mgid, do modify qp with this mrec qkey (=ipv4 broadcast one)

++ on the rdmacm user space code: (librdmacm/src/cma.c)

+3 on rdma_create_qp do modify qp with some def qkey (eg zero)
+4 on the join completion path before attaching a qp to the associated
mgid, do modify qp with this mrec qkey (=ipv4 broadcast one)

With the time frame for 2.6.21 and OFED 1.2 becoming short, can you 
update of the multicast patch series status? We really want it in for 
this time frame, please let me know if you prefer to get patches that 
implement the above (eg as reference) or do it yourself...

thanks,

Or.