RE: [PATCH] vdpa: regist vhost-vdpa dev class

[Longpeng (Mike, Cloud Infrastructure Service Product Dept.)]

> -----Original Message-----
> From: Yi Wang [mailto:wang.yi59@xxxxxxxxxx]
> Sent: Thursday, December 23, 2021 3:32 PM
> To: mst@xxxxxxxxxx
> Cc: jasowang@xxxxxxxxxx; kvm@xxxxxxxxxxxxxxx;
> virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; xue.zhihong@xxxxxxxxxx; wang.yi59@xxxxxxxxxx;
> wang.liang82@xxxxxxxxxx; Zhang Min <zhang.min9@xxxxxxxxxx>
> Subject: [PATCH] vdpa: regist vhost-vdpa dev class
> 
> From: Zhang Min <zhang.min9@xxxxxxxxxx>
> 
> Some applications like kata-containers need to acquire MAJOR/MINOR/DEVNAME
> for devInfo [1], so regist vhost-vdpa dev class to expose uevent.
> 
> 1.
> https://github.com/kata-containers/kata-containers/blob/main/src/runtime/vi
> rtcontainers/device/config/config.go
> 
> Signed-off-by: Zhang Min <zhang.min9@xxxxxxxxxx>
> Signed-off-by: Yi Wang <wang.yi59@xxxxxxxxxx>
> ---
>  drivers/vhost/vdpa.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index fb41db3da611..90fbad93e7a2 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -1012,6 +1012,7 @@ static void vhost_vdpa_release_dev(struct device *device)
>  	kfree(v);
>  }
> 
> +static struct class *vhost_vdpa_class;
>  static int vhost_vdpa_probe(struct vdpa_device *vdpa)
>  {
>  	const struct vdpa_config_ops *ops = vdpa->config;
> @@ -1040,6 +1041,7 @@ static int vhost_vdpa_probe(struct vdpa_device *vdpa)
>  	v->dev.release = vhost_vdpa_release_dev;
>  	v->dev.parent = &vdpa->dev;
>  	v->dev.devt = MKDEV(MAJOR(vhost_vdpa_major), minor);
> +	v->dev.class = vhost_vdpa_class;
>  	v->vqs = kmalloc_array(v->nvqs, sizeof(struct vhost_virtqueue),
>  			       GFP_KERNEL);
>  	if (!v->vqs) {
> @@ -1097,6 +1099,14 @@ static int __init vhost_vdpa_init(void)
>  {
>  	int r;
> 
> +	vhost_vdpa_class = class_create(THIS_MODULE, "vhost-vdpa");
> +	if (IS_ERR(vhost_vdpa_class)) {
> +		r = PTR_ERR(vhost_vdpa_class);
> +		pr_warn("vhost vdpa class create error %d,  maybe mod reinserted\n", r);
> +		vhost_vdpa_class = NULL;

Unnecessary to reset?

> +		return r;
> +	}
> +
>  	r = alloc_chrdev_region(&vhost_vdpa_major, 0, VHOST_VDPA_DEV_MAX,
>  				"vhost-vdpa");
>  	if (r)
> @@ -1111,6 +1121,7 @@ static int __init vhost_vdpa_init(void)
>  err_vdpa_register_driver:
>  	unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
>  err_alloc_chrdev:
> +	class_destroy(vhost_vdpa_class);
>  	return r;
>  }
>  module_init(vhost_vdpa_init);
> @@ -1118,6 +1129,7 @@ module_init(vhost_vdpa_init);
>  static void __exit vhost_vdpa_exit(void)
>  {
>  	vdpa_unregister_driver(&vhost_vdpa_driver);
> +	class_destroy(vhost_vdpa_class);
>  	unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
>  }
>  module_exit(vhost_vdpa_exit);
> --
> 2.27.0