cqe->op_own indicates if the CQE is owned by the NIC. The rest of
the fields in CQE should be read only after op_own is read. On Arm
platforms using "dmb ishld" is sufficient to enforce this.
Fixes: 88c0733535d6 ("net/mlx5: extend Rx completion with error handling")
Cc: ma...@mellanox.com
Cc: sta...@dpdk.org
Signed-off-by: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com>
---
drivers/common/mlx5/mlx5_common.h | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/common/mlx5/mlx5_common.h
b/drivers/common/mlx5/mlx5_common.h
index 5028a05b49..ac2e85b15f 100644
--- a/drivers/common/mlx5/mlx5_common.h
+++ b/drivers/common/mlx5/mlx5_common.h
@@ -195,7 +195,11 @@ check_cqe(volatile struct mlx5_cqe *cqe, const uint16_t
cqes_n,
if (unlikely((op_owner != (!!(idx))) || (op_code == MLX5_CQE_INVALID)))
return MLX5_CQE_STATUS_HW_OWN;
- rte_io_rmb();
+ /* Prevent speculative reading of other fields in CQE until
+ * CQE is valid.
+ */
+ rte_atomic_thread_fence(__ATOMIC_ACQUIRE);
+
if (unlikely(op_code == MLX5_CQE_RESP_ERR ||
op_code == MLX5_CQE_REQ_ERR))
return MLX5_CQE_STATUS_ERR;
--
2.17.1
