4.20-stable review patch. If anyone has any objections, please let me know.
------------------
[ Upstream commit b024dd0eba6e6d568f69d63c5e3153aba94c23e3 ]
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@gmail.com Signed-off-by: Chuck Lever chuck.lever@oracle.com Reviewed-by: Sagi Grimberg sagi@grimberg.me Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 6c361d70d7cd..46f62f71cd28 100644 --- a/drivers/infiniband/sw/rxe/rxe_req.c +++ b/drivers/infiniband/sw/rxe/rxe_req.c @@ -643,6 +643,7 @@ next_wqe: 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 {