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References: <20230928164550.980832-2-dtatulea@nvidia.com> <20230928164550.980832-9-dtatulea@nvidia.com>
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From:   Eugenio Perez Martin <eperezma@redhat.com>
Date:   Wed, 4 Oct 2023 20:40:27 +0200
Message-ID: <CAJaqyWdAxy7wOwpR=-jrqKL-BErarC1P+FmiDk_q7fpCLxU7pA@mail.gmail.com>
Subject: Re: [PATCH vhost 07/16] vdpa/mlx5: Take cvq iotlb lock during refresh
To:     Dragos Tatulea <dtatulea@nvidia.com>
Cc:     gal@nvidia.com, "Michael S . Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>,
        Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
        virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
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On Thu, Sep 28, 2023 at 6:50=E2=80=AFPM Dragos Tatulea <dtatulea@nvidia.com=
> 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@redhat.=
com/
>
> Acked-by: Jason Wang <jasowang@redhat.com>
> Suggested-by: Eugenio P=C3=A9rez <eperezma@redhat.com>

Reviewed-by: Eugenio P=C3=A9rez <eperezma@redhat.com>

> Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
> ---
>  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] !=3D asid)
>                 return 0;
>
> +       spin_lock(&mvdev->cvq.iommu_lock);
> +
>         prune_iotlb(mvdev);
> -       return dup_iotlb(mvdev, iotlb);
> +       err =3D 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
>