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In-Reply-To: <1676424640-11673-1-git-send-email-si-wei.liu@oracle.com>
From:   Jason Wang <jasowang@redhat.com>
Date:   Thu, 16 Feb 2023 12:48:48 +0800
Message-ID: <CACGkMEuckWowpA9q+ez0-U4FicamQ+5zXfumtQMA25jXpvL7uw@mail.gmail.com>
Subject: Re: [PATCH v3] vdpa/mlx5: should not activate virtq object when suspended
To:     Si-Wei Liu <si-wei.liu@oracle.com>
Cc:     mst@redhat.com, elic@nvidia.com, parav@nvidia.com,
        virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org, eperezma@redhat.com
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On Wed, Feb 15, 2023 at 9:31 AM Si-Wei Liu <si-wei.liu@oracle.com> wrote:
>
> Otherwise the virtqueue object to instate could point to invalid address
> that was unmapped from the MTT:
>
>   mlx5_core 0000:41:04.2: mlx5_cmd_out_err:782:(pid 8321):
>   CREATE_GENERAL_OBJECT(0xa00) op_mod(0xd) failed, status
>   bad parameter(0x3), syndrome (0x5fa1c), err(-22)
>
> Fixes: cae15c2ed8e6 ("vdpa/mlx5: Implement susupend virtqueue callback")
> Cc: Eli Cohen <elic@nvidia.com>
> Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
> Reviewed-by: Eli Cohen <elic@nvidia.com>
>
> ---
> v3: move suspended to struct mlx5_vdpa_dev
> v2: removed the change for improving warning message
> ---
>  drivers/vdpa/mlx5/core/mlx5_vdpa.h | 1 +
>  drivers/vdpa/mlx5/net/mlx5_vnet.c  | 6 +++++-
>  2 files changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vdpa/mlx5/core/mlx5_vdpa.h b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
> index 058fbe2..25fc412 100644
> --- a/drivers/vdpa/mlx5/core/mlx5_vdpa.h
> +++ b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
> @@ -96,6 +96,7 @@ struct mlx5_vdpa_dev {
>         struct mlx5_control_vq cvq;
>         struct workqueue_struct *wq;
>         unsigned int group2asid[MLX5_VDPA_NUMVQ_GROUPS];
> +       bool suspended;
>  };
>
>  int mlx5_vdpa_alloc_pd(struct mlx5_vdpa_dev *dev, u32 *pdn, u16 uid);
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 3a6dbbc6..daac3ab 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -2411,7 +2411,7 @@ static int mlx5_vdpa_change_map(struct mlx5_vdpa_dev *mvdev,
>         if (err)
>                 goto err_mr;
>
> -       if (!(mvdev->status & VIRTIO_CONFIG_S_DRIVER_OK))
> +       if (!(mvdev->status & VIRTIO_CONFIG_S_DRIVER_OK) || mvdev->suspended)

One more thought,

Does this mean set_map() is forbidden during suspending? I'm not sure
this is correct or at least we need restrict in in the vDPA core.

Thanks

>                 goto err_mr;
>
>         restore_channels_info(ndev);
> @@ -2579,6 +2579,7 @@ static int mlx5_vdpa_reset(struct vdpa_device *vdev)
>         clear_vqs_ready(ndev);
>         mlx5_vdpa_destroy_mr(&ndev->mvdev);
>         ndev->mvdev.status = 0;
> +       ndev->mvdev.suspended = false;
>         ndev->cur_num_vqs = 0;
>         ndev->mvdev.cvq.received_desc = 0;
>         ndev->mvdev.cvq.completed_desc = 0;
> @@ -2815,6 +2816,8 @@ static int mlx5_vdpa_suspend(struct vdpa_device *vdev)
>         struct mlx5_vdpa_virtqueue *mvq;
>         int i;
>
> +       mlx5_vdpa_info(mvdev, "suspending device\n");
> +
>         down_write(&ndev->reslock);
>         ndev->nb_registered = false;
>         mlx5_notifier_unregister(mvdev->mdev, &ndev->nb);
> @@ -2824,6 +2827,7 @@ static int mlx5_vdpa_suspend(struct vdpa_device *vdev)
>                 suspend_vq(ndev, mvq);
>         }
>         mlx5_vdpa_cvq_suspend(mvdev);
> +       mvdev->suspended = true;
>         up_write(&ndev->reslock);
>         return 0;
>  }
> --
> 1.8.3.1
>