[ofa-general] [PATCH RFC v3 1/2] RDMA/Core: MEM_MGT_EXTENSIONS support

[Steve Wise]

Or Gerlitz wrote:
> Steve Wise wrote:
>> Are we sure we need to expose this to the user?
> I believe this is the way to go if we want to let smart ULPs generate 
> new rkey/stag per mapping. Simpler ULPs could then just put the same 
> value for each map associated with the same mr.
>
> Or.
>

How should I add this to the API?

Perhaps we just document the format of an rkey in the struct ib_mr.  
Thus the app would do this to change the key before posting the 
fast_reg_mr wr (coded to be explicit, not efficient):

u8 newkey;
u32 newrkey;

newkey = 0xaa;
newrkey = (mr->rkey & 0xffffff00) | newkey;
mr->rkey = newrkey
wr.wr.fast_reg.mr = mr;
...


Note, this assumes mr->rkey is in host byte order (I think the linux 
rdma code assumes this in other places too).


Steve.