Subject: Re: [PATCH v2] vdpa/mlx5: Enable user to add/delete vdpa device

From: "Michael S. Tsirkin" <[email-masked]>
Date: Tue, 23 Feb 2021 07:29:32 -0500

On Thu, Feb 18, 2021 at 09:41:57AM +0200, Eli Cohen wrote:
> Allow to control vdpa device creation and destruction using the vdpa
> management tool.
> 
> Examples:
> 1. List the management devices
> $ vdpa mgmtdev show
> pci/0000:3b:00.1:
>   supported_classes net
> 
> 2. Create vdpa instance
> $ vdpa dev add mgmtdev pci/0000:3b:00.1 name vdpa0
> 
> 3. Show vdpa devices
> $ vdpa dev show
> vdpa0: type network mgmtdev pci/0000:3b:00.1 vendor_id 5555 max_vqs 16 \
> max_vq_size 256
> 
> Signed-off-by: Eli Cohen <[email-masked]>
> Reviewed-by: Parav Pandit <[email-masked]>

Not sure which tree this is for, I could not apply this.

> ---
> v0->v1:
> set mgtdev->ndev NULL on dev delete
> v1->v2: Resend
> 
>  drivers/vdpa/mlx5/net/mlx5_vnet.c | 79 +++++++++++++++++++++++++++----
>  1 file changed, 70 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index a51b0f86afe2..08fb481ddc4f 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -1974,23 +1974,32 @@ static void init_mvqs(struct mlx5_vdpa_net *ndev)
>  	}
>  }
>  
> -static int mlx5v_probe(struct auxiliary_device *adev,
> -		       const struct auxiliary_device_id *id)
> +struct mlx5_vdpa_mgmtdev {
> +	struct vdpa_mgmt_dev mgtdev;
> +	struct mlx5_adev *madev;
> +	struct mlx5_vdpa_net *ndev;
> +};
> +
> +static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name)
>  {
> -	struct mlx5_adev *madev = container_of(adev, struct mlx5_adev, adev);
> -	struct mlx5_core_dev *mdev = madev->mdev;
> +	struct mlx5_vdpa_mgmtdev *mgtdev = container_of(v_mdev, struct mlx5_vdpa_mgmtdev, mgtdev);
>  	struct virtio_net_config *config;
>  	struct mlx5_vdpa_dev *mvdev;
>  	struct mlx5_vdpa_net *ndev;
> +	struct mlx5_core_dev *mdev;
>  	u32 max_vqs;
>  	int err;
>  
> +	if (mgtdev->ndev)
> +		return -ENOSPC;
> +
> +	mdev = mgtdev->madev->mdev;
>  	/* we save one virtqueue for control virtqueue should we require it */
>  	max_vqs = MLX5_CAP_DEV_VDPA_EMULATION(mdev, max_num_virtio_queues);
>  	max_vqs = min_t(u32, max_vqs, MLX5_MAX_SUPPORTED_VQS);
>  
>  	ndev = vdpa_alloc_device(struct mlx5_vdpa_net, mvdev.vdev, mdev->device, &mlx5_vdpa_ops,
> -				 2 * mlx5_vdpa_max_qps(max_vqs), NULL);
> +				 2 * mlx5_vdpa_max_qps(max_vqs), name);
>  	if (IS_ERR(ndev))
>  		return PTR_ERR(ndev);
>  
> @@ -2018,11 +2027,12 @@ static int mlx5v_probe(struct auxiliary_device *adev,
>  	if (err)
>  		goto err_res;
>  
> -	err = vdpa_register_device(&mvdev->vdev);
> +	mvdev->vdev.mdev = &mgtdev->mgtdev;
> +	err = _vdpa_register_device(&mvdev->vdev);
>  	if (err)
>  		goto err_reg;
>  
> -	dev_set_drvdata(&adev->dev, ndev);
> +	mgtdev->ndev = ndev;
>  	return 0;
>  
>  err_reg:
> @@ -2035,11 +2045,62 @@ static int mlx5v_probe(struct auxiliary_device *adev,
>  	return err;
>  }
>  
> +static void mlx5_vdpa_dev_del(struct vdpa_mgmt_dev *v_mdev, struct vdpa_device *dev)
> +{
> +	struct mlx5_vdpa_mgmtdev *mgtdev = container_of(v_mdev, struct mlx5_vdpa_mgmtdev, mgtdev);
> +
> +	_vdpa_unregister_device(dev);
> +	mgtdev->ndev = NULL;
> +}
> +
> +static const struct vdpa_mgmtdev_ops mdev_ops = {
> +	.dev_add = mlx5_vdpa_dev_add,
> +	.dev_del = mlx5_vdpa_dev_del,
> +};
> +
> +static struct virtio_device_id id_table[] = {
> +	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
> +	{ 0 },
> +};
> +
> +static int mlx5v_probe(struct auxiliary_device *adev,
> +		       const struct auxiliary_device_id *id)
> +
> +{
> +	struct mlx5_adev *madev = container_of(adev, struct mlx5_adev, adev);
> +	struct mlx5_core_dev *mdev = madev->mdev;
> +	struct mlx5_vdpa_mgmtdev *mgtdev;
> +	int err;
> +
> +	mgtdev = kzalloc(sizeof(*mgtdev), GFP_KERNEL);
> +	if (!mgtdev)
> +		return -ENOMEM;
> +
> +	mgtdev->mgtdev.ops = &mdev_ops;
> +	mgtdev->mgtdev.device = mdev->device;
> +	mgtdev->mgtdev.id_table = id_table;
> +	mgtdev->madev = madev;
> +
> +	err = vdpa_mgmtdev_register(&mgtdev->mgtdev);
> +	if (err)
> +		goto reg_err;
> +
> +	dev_set_drvdata(&adev->dev, mgtdev);
> +
> +	return 0;
> +
> +reg_err:
> +	kfree(mdev);
> +	return err;
> +}
> +
>  static void mlx5v_remove(struct auxiliary_device *adev)
>  {
> -	struct mlx5_vdpa_dev *mvdev = dev_get_drvdata(&adev->dev);
> +	struct mlx5_vdpa_mgmtdev *mgtdev;
>  
> -	vdpa_unregister_device(&mvdev->vdev);
> +	mgtdev = dev_get_drvdata(&adev->dev);
> +	vdpa_mgmtdev_unregister(&mgtdev->mgtdev);
> +	kfree(mgtdev);
>  }
>  
>  static const struct auxiliary_device_id mlx5v_id_table[] = {
> -- 
> 2.29.2