[PATCH rdma-rc] RDMA/mlx5: Prevent UMR usage with RO only when we have RO caps

[PATCH rdma-rc] RDMA/mlx5: Prevent UMR usage with RO only when we have RO caps

[Leon Romanovsky]

From: Michael Guralnik <michaelgur@mellanox.com>

Relaxed ordering is not supported in UMR so we are disabling UMR usage
when user passes relaxed ordering access flag.

Enable using UMR when user requested relaxed ordering but there are no
relaxed ordering capabilities.
This will prevent user from unnecessarily registering a new mkey.

Fixes: d6de0bb1850f ("RDMA/mlx5: Set relaxed ordering when requested")
Signed-off-by: Michael Guralnik <michaelgur@mellanox.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
---
 drivers/infiniband/hw/mlx5/mlx5_ib.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index d9bffcc93587..f21d446249b8 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -1532,7 +1532,9 @@ static inline bool mlx5_ib_can_use_umr(struct mlx5_ib_dev *dev,
 	    MLX5_CAP_GEN(dev->mdev, umr_modify_atomic_disabled))
 		return false;
 
-	if (access_flags & IB_ACCESS_RELAXED_ORDERING)
+	if (access_flags & IB_ACCESS_RELAXED_ORDERING &&
+	    (MLX5_CAP_GEN(dev->mdev, relaxed_ordering_write) ||
+	     MLX5_CAP_GEN(dev->mdev, relaxed_ordering_read)))
 		return false;
 
 	return true;
-- 
2.24.1

Re: [PATCH rdma-rc] RDMA/mlx5: Prevent UMR usage with RO only when we have RO caps

[Jason Gunthorpe]

On Thu, Feb 27, 2020 at 01:38:34PM +0200, Leon Romanovsky wrote:
> From: Michael Guralnik <michaelgur@mellanox.com>
> 
> Relaxed ordering is not supported in UMR so we are disabling UMR usage
> when user passes relaxed ordering access flag.
> 
> Enable using UMR when user requested relaxed ordering but there are no
> relaxed ordering capabilities.
> This will prevent user from unnecessarily registering a new mkey.
> 
> Fixes: d6de0bb1850f ("RDMA/mlx5: Set relaxed ordering when requested")
> Signed-off-by: Michael Guralnik <michaelgur@mellanox.com>
> Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
> Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
> ---
>  drivers/infiniband/hw/mlx5/mlx5_ib.h | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)

This doesn't seem very rc-ish, applied to for-next

Thanks,
Jason