On Tue, Jun 28, 2022 at 10:04 PM Bob Pearson <rpearsonhpe@xxxxxxxxx> wrote: > > 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. When you say "rkey is asked for", you mean the access permissions (LOCAL/REMOTE) asked for that MR right? If so, then for RXE to decide which key to compare with while invalidating, it's better to decide based on the access of the MR (basically fix number 2 from my older email). > > Bob
