Re: [PATCH v7 02/19] iommufd: Add iommufd_group

[Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx>]

On 5/15/23 10:00 PM, Jason Gunthorpe wrote:
>   void iommufd_device_destroy(struct iommufd_object *obj)
>   {
>   	struct iommufd_device *idev =
>   		container_of(obj, struct iommufd_device, obj);
>   
>   	iommu_device_release_dma_owner(idev->dev);
> -	iommu_group_put(idev->group);
> +	iommufd_put_group(idev->igroup);
>   	if (!iommufd_selftest_is_mock_dev(idev->dev))
>   		iommufd_ctx_put(idev->ictx);
>   }
> @@ -46,7 +154,7 @@ struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx,
>   					   struct device *dev, u32 *id)
>   {
>   	struct iommufd_device *idev;
> -	struct iommu_group *group;
> +	struct iommufd_group *igroup;
>   	int rc;
>   
>   	/*
> @@ -56,9 +164,9 @@ struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx,
>   	if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY))
>   		return ERR_PTR(-EINVAL);
>   
> -	group = iommu_group_get(dev);
> -	if (!group)
> -		return ERR_PTR(-ENODEV);
> +	igroup = iommufd_get_group(ictx, dev);
> +	if (IS_ERR(igroup))
> +		return ERR_CAST(igroup);
>   
>   	/*
>   	 * For historical compat with VFIO the insecure interrupt path is

Hi Jason,

Perhaps I am asking a silly question. The iommufd_group is get in
iommufd_device_bind(), but put in iommufd_device_destroy(). Why not put
it in iommufd_device_unbind()?

Best regards,
baolu