RE: [PATCH v3 4/4] vfio/type1: Use iommu_aux_at(de)tach_group() APIs

["Liu, Yi L" <yi.l.liu@intel.com>]

> From: Lu Baolu <baolu.lu@linux.intel.com>
> Sent: Tuesday, July 14, 2020 1:57 PM
> 
> Replace iommu_aux_at(de)tach_device() with iommu_aux_at(de)tach_group().
> It also saves the IOMMU_DEV_FEAT_AUX-capable physcail device in the vfio_group
> data structure so that it could be reused in other places.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  drivers/vfio/vfio_iommu_type1.c | 44 ++++++---------------------------
>  1 file changed, 7 insertions(+), 37 deletions(-)
> 
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 5e556ac9102a..f8812e68de77 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -100,6 +100,7 @@ struct vfio_dma {
>  struct vfio_group {
>  	struct iommu_group	*iommu_group;
>  	struct list_head	next;
> +	struct device		*iommu_device;

I know mdev group has only one device, so such a group has a single
iommu_device. But I guess may be helpful to add a comment here or in
commit message. Otherwise, it looks weird that a group structure
contains a single iommu_device field instead of a list of iommu_device.

Regards,
Yi Liu

>  	bool			mdev_group;	/* An mdev group */
>  	bool			pinned_page_dirty_scope;
>  };
> @@ -1627,45 +1628,13 @@ static struct device
> *vfio_mdev_get_iommu_device(struct device *dev)
>  	return NULL;
>  }
> 
> -static int vfio_mdev_attach_domain(struct device *dev, void *data) -{
> -	struct iommu_domain *domain = data;
> -	struct device *iommu_device;
> -
> -	iommu_device = vfio_mdev_get_iommu_device(dev);
> -	if (iommu_device) {
> -		if (iommu_dev_feature_enabled(iommu_device,
> IOMMU_DEV_FEAT_AUX))
> -			return iommu_aux_attach_device(domain, iommu_device);
> -		else
> -			return iommu_attach_device(domain, iommu_device);
> -	}
> -
> -	return -EINVAL;
> -}
> -
> -static int vfio_mdev_detach_domain(struct device *dev, void *data) -{
> -	struct iommu_domain *domain = data;
> -	struct device *iommu_device;
> -
> -	iommu_device = vfio_mdev_get_iommu_device(dev);
> -	if (iommu_device) {
> -		if (iommu_dev_feature_enabled(iommu_device,
> IOMMU_DEV_FEAT_AUX))
> -			iommu_aux_detach_device(domain, iommu_device);
> -		else
> -			iommu_detach_device(domain, iommu_device);
> -	}
> -
> -	return 0;
> -}
> -
>  static int vfio_iommu_attach_group(struct vfio_domain *domain,
>  				   struct vfio_group *group)
>  {
>  	if (group->mdev_group)
> -		return iommu_group_for_each_dev(group->iommu_group,
> -						domain->domain,
> -						vfio_mdev_attach_domain);
> +		return iommu_aux_attach_group(domain->domain,
> +					      group->iommu_group,
> +					      group->iommu_device);
>  	else
>  		return iommu_attach_group(domain->domain, group-
> >iommu_group);  } @@ -1674,8 +1643,8 @@ static void
> vfio_iommu_detach_group(struct vfio_domain *domain,
>  				    struct vfio_group *group)
>  {
>  	if (group->mdev_group)
> -		iommu_group_for_each_dev(group->iommu_group, domain-
> >domain,
> -					 vfio_mdev_detach_domain);
> +		iommu_aux_detach_group(domain->domain, group->iommu_group,
> +				       group->iommu_device);
>  	else
>  		iommu_detach_group(domain->domain, group->iommu_group);  }
> @@ -2007,6 +1976,7 @@ static int vfio_iommu_type1_attach_group(void
> *iommu_data,
>  			return 0;
>  		}
> 
> +		group->iommu_device = iommu_device;
>  		bus = iommu_device->bus;
>  	}
> 
> --
> 2.17.1

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