On 6/28/22 12:05, haris iqbal wrote: > On Tue, Jun 28, 2022 at 6:50 PM Jason Gunthorpe <jgg@xxxxxxxx> wrote: >> >> On Tue, Jun 28, 2022 at 06:46:39PM +0200, haris iqbal wrote: >>> On Tue, Jun 28, 2022 at 6:34 PM Jason Gunthorpe <jgg@xxxxxxxx> wrote: >>>> >>>> On Tue, Jun 28, 2022 at 06:21:09PM +0200, haris iqbal wrote: >>>> >>>>>> Yes, no driver in Linux suports a disjoint key space. >>>>> >>>>> If disjoint key space is not supported in Linux; does this mean >>>>> irrespective of whether an MR is registered (IB_WR_REG_MR) for LOCAL >>>>> or REMOTE access, both rkey and lkey should be set? >>>> >>>> No.. It means given any key the driver can always tell if it is a rkey >>>> or a lkey. There is never any aliasing of key values. Thus the API >>>> often doesn't have a away to tell if the given key is an rkey or lkey. >>>> >>>>> PS: This discussion started in the following thread, >>>>> https://marc.info/?l=linux-rdma&m=165390868832428&w=2 >>>> >>>> rxe is incorrect to not accept the lkey presented on the >>>> invalidate_rkey input. invalidate_rkey is misnamed. >>> >>> >>> Understood. So a better fix for rxe (as compared to the one I sent) >>> would be one of the following (if I understand correctly). >>> >>> 1) The key sent in INV, is compared with lkey or rkey based on which >>> one is set (non-zero). >> >> This one seems to match the spec >> >> However, it requires that keys don't alias, I don't know if rxe has >> done this. > > Rxe seems to be NOT aliasing for fast reg. Unsure about other cases. > > Maybe Bob or Zhu can shed some light? > >> >>> OR, >>> 2) The key sent in INV, is compared with lkey if the MR has only LOCAL >>> access, and rkey if the MR has REMOTE access. >> >> That might make more sense if rxe has aliasing keys and you need to be >> specific about r/l >> >> Jason rxe always has lkey=rkey if rkey is asked for else rkey=0 and lkey is always set. Bob
