[RFC v2 6/9] VFIO: Extend external user API

[christoffer.dall@linaro.org (Christoffer Dall)]

On Mon, Sep 01, 2014 at 02:52:45PM +0200, Eric Auger wrote:
> New functions are added to be called from ARM KVM-VFIO device.

This commit message seems somewhat random.  This patch doesn't deal with
anything ARM specific, it introduces some generic functions that allows
users external to vfio itself to retrieve information about a vfio
platform device.

> 
> - vfio_device_get_external_user enables to get a vfio device from
>   its fd
> - vfio_device_put_external_user puts the vfio device
> - vfio_external_base_device returns the struct device*,
>   useful to access the platform_device
> 
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> 
> ---
> 
> v1 -> v2:
> 
> - vfio_external_get_base_device renamed into vfio_external_base_device
> - vfio_external_get_type removed
> ---
>  drivers/vfio/vfio.c  | 24 ++++++++++++++++++++++++
>  include/linux/vfio.h |  3 +++
>  2 files changed, 27 insertions(+)
> 
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 8e84471..282814e 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -1401,6 +1401,30 @@ void vfio_group_put_external_user(struct vfio_group *group)
>  }
>  EXPORT_SYMBOL_GPL(vfio_group_put_external_user);
>  
> +struct vfio_device *vfio_device_get_external_user(struct file *filep)
> +{
> +	struct vfio_device *vdev = filep->private_data;
> +
> +	if (filep->f_op != &vfio_device_fops)
> +		return ERR_PTR(-EINVAL);
> +
> +	vfio_device_get(vdev);
> +	return vdev;
> +}
> +EXPORT_SYMBOL_GPL(vfio_device_get_external_user);
> +
> +void vfio_device_put_external_user(struct vfio_device *vdev)
> +{
> +	vfio_device_put(vdev);
> +}
> +EXPORT_SYMBOL_GPL(vfio_device_put_external_user);
> +
> +struct device *vfio_external_base_device(struct vfio_device *vdev)
> +{
> +	return vdev->dev;
> +}
> +EXPORT_SYMBOL_GPL(vfio_external_base_device);
> +
>  int vfio_external_user_iommu_id(struct vfio_group *group)
>  {
>  	return iommu_group_id(group->iommu_group);
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index ffe04ed..bd4b6cb 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -99,6 +99,9 @@ extern void vfio_group_put_external_user(struct vfio_group *group);
>  extern int vfio_external_user_iommu_id(struct vfio_group *group);
>  extern long vfio_external_check_extension(struct vfio_group *group,
>  					  unsigned long arg);
> +extern struct vfio_device *vfio_device_get_external_user(struct file *filep);
> +extern void vfio_device_put_external_user(struct vfio_device *vdev);
> +extern struct device *vfio_external_base_device(struct vfio_device *vdev);
>  
>  struct pci_dev;
>  #ifdef CONFIG_EEH
> -- 
> 1.9.1
> 
Looks good to me,
-Christoffer