FRWR memory registration is done with a series of calls and WRs.
1. ULP invokes ib_dma_map_sg()
2. ULP invokes ib_map_mr_sg()
3. ULP posts an IB_WR_REG_MR on the Send queue
Step 2 generates an iova. It is permissible for ULPs to change
this iova (with certain restrictions) between steps 2 and 3.
rxe_map_mr_sg captures the MR's iova but later when rxe processes
the REG_MR WR, it ignores the MR's iova field. If a ULP alters the
MR's iova after step 2 but before step 3, rxe never captures that
change.
When the remote sends an RDMA Read targeting that MR, rxe looks up
the R_key, but the altered iova does not match the iova stored in
the MR, causing the RDMA Read request to fail.
Reported-by: Anna Schumaker <schumaker.anna@xxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
---
drivers/infiniband/sw/rxe/rxe_req.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/infiniband/sw/rxe/rxe_req.c b/drivers/infiniband/sw/rxe/rxe_req.c
index 6c361d7..46f62f7 100644
--- a/drivers/infiniband/sw/rxe/rxe_req.c
+++ b/drivers/infiniband/sw/rxe/rxe_req.c
@@ -643,6 +643,7 @@ int rxe_requester(void *arg)
rmr->access = wqe->wr.wr.reg.access;
rmr->lkey = wqe->wr.wr.reg.key;
rmr->rkey = wqe->wr.wr.reg.key;
+ rmr->iova = wqe->wr.wr.reg.mr->iova;
wqe->state = wqe_state_done;
wqe->status = IB_WC_SUCCESS;
} else {
