From: Kaike Wan kaike.wan@intel.com
commit b25e8e85e75a61af1ddc88c4798387dd3132dd43 upstream.
The following message occurs when running an AI application with TID RDMA enabled:
hfi1 0000:7f:00.0: hfi1_0: [QP74] hfi1_tid_timeout 4084 hfi1 0000:7f:00.0: hfi1_0: [QP70] hfi1_tid_timeout 4084
The issue happens when TID RDMA WRITE request is followed by an IB_WR_RDMA_WRITE_WITH_IMM request, the latter could be completed first on the responder side. As a result, no ACK packet for the latter could be sent because the TID RDMA WRITE request is still being processed on the responder side.
When the TID RDMA WRITE request is eventually completed, the requester will wait for the IB_WR_RDMA_WRITE_WITH_IMM request to be acknowledged.
If the next request is another TID RDMA WRITE request, no TID RDMA WRITE DATA packet could be sent because the preceding IB_WR_RDMA_WRITE_WITH_IMM request is not completed yet.
Consequently the IB_WR_RDMA_WRITE_WITH_IMM will be retried but it will be ignored on the responder side because the responder thinks it has already been completed. Eventually the retry will be exhausted and the qp will be put into error state on the requester side. On the responder side, the TID resource timer will eventually expire because no TID RDMA WRITE DATA packets will be received for the second TID RDMA WRITE request. There is also risk of a write-after-write memory corruption due to the issue.
Fix by adding a requester side interlock to prevent any potential data corruption and TID RDMA protocol error.
Fixes: a0b34f75ec20 ("IB/hfi1: Add interlock between a TID RDMA request and other requests") Link: https://lore.kernel.org/r/20200811174931.191210.84093.stgit@awfm-01.aw.intel... Cc: stable@vger.kernel.org # 5.4.x+ Reviewed-by: Mike Marciniszyn mike.marciniszyn@intel.com Reviewed-by: Dennis Dalessandro dennis.dalessandro@intel.com Signed-off-by: Kaike Wan kaike.wan@intel.com Signed-off-by: Mike Marciniszyn mike.marciniszyn@intel.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/hw/hfi1/tid_rdma.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/infiniband/hw/hfi1/tid_rdma.c +++ b/drivers/infiniband/hw/hfi1/tid_rdma.c @@ -3215,6 +3215,7 @@ bool hfi1_tid_rdma_wqe_interlock(struct case IB_WR_ATOMIC_CMP_AND_SWP: case IB_WR_ATOMIC_FETCH_AND_ADD: case IB_WR_RDMA_WRITE: + case IB_WR_RDMA_WRITE_WITH_IMM: switch (prev->wr.opcode) { case IB_WR_TID_RDMA_WRITE: req = wqe_to_tid_req(prev);