Re: [PATCH vhost 07/16] vdpa/mlx5: Take cvq iotlb lock during refresh

[Eugenio Perez Martin]

On Thu, Sep 28, 2023 at 6:50 PM Dragos Tatulea <dtatulea@xxxxxxxxxx> wrote:
>
> The reslock is taken while refresh is called but iommu_lock is more
> specific to this resource. So take the iommu_lock during cvq iotlb
> refresh.
>
> Based on Eugenio's patch [0].
>
> [0] https://lore.kernel.org/lkml/20230112142218.725622-4-eperezma@xxxxxxxxxx/
>
> Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
> Suggested-by: Eugenio Pérez <eperezma@xxxxxxxxxx>

Reviewed-by: Eugenio Pérez <eperezma@xxxxxxxxxx>

> Signed-off-by: Dragos Tatulea <dtatulea@xxxxxxxxxx>
> ---
>  drivers/vdpa/mlx5/core/mr.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
> index fcb6ae32e9ed..587300e7c18e 100644
> --- a/drivers/vdpa/mlx5/core/mr.c
> +++ b/drivers/vdpa/mlx5/core/mr.c
> @@ -590,11 +590,19 @@ int mlx5_vdpa_update_cvq_iotlb(struct mlx5_vdpa_dev *mvdev,
>                                 struct vhost_iotlb *iotlb,
>                                 unsigned int asid)
>  {
> +       int err;
> +
>         if (mvdev->group2asid[MLX5_VDPA_CVQ_GROUP] != asid)
>                 return 0;
>
> +       spin_lock(&mvdev->cvq.iommu_lock);
> +
>         prune_iotlb(mvdev);
> -       return dup_iotlb(mvdev, iotlb);
> +       err = dup_iotlb(mvdev, iotlb);
> +
> +       spin_unlock(&mvdev->cvq.iommu_lock);
> +
> +       return err;
>  }
>
>  int mlx5_vdpa_create_dma_mr(struct mlx5_vdpa_dev *mvdev)
> --
> 2.41.0
>