> From: Liu, Yi L <yi.l.liu@xxxxxxxxx>
> Sent: Tuesday, January 17, 2023 9:50 PM
> static int vfio_device_group_open(struct vfio_device_file *df)
> {
> struct vfio_device *device = df->device;
> + u32 ioas_id;
> + u32 *pt_id = NULL;
> int ret;
>
> mutex_lock(&device->group->group_lock);
> @@ -165,6 +167,14 @@ static int vfio_device_group_open(struct
> vfio_device_file *df)
> goto err_unlock_group;
> }
>
> + if (device->group->iommufd) {
> + ret = iommufd_vfio_compat_ioas_id(device->group-
> >iommufd,
> + &ioas_id);
> + if (ret)
> + goto err_unlock_group;
> + pt_id = &ioas_id;
> + }
> +
> mutex_lock(&device->dev_set->lock);
> /*
> * Here we pass the KVM pointer with the group under the lock. If
> the
> @@ -174,7 +184,7 @@ static int vfio_device_group_open(struct
> vfio_device_file *df)
> df->kvm = device->group->kvm;
> df->iommufd = device->group->iommufd;
>
> - ret = vfio_device_open(df);
> + ret = vfio_device_open(df, NULL, pt_id);
having both ioas_id and pt_id in one function is a bit confusing.
Does it read better with below?
if (device->group->iommufd)
ret = vfio_device_open(df, NULL, &ioas_id);
else
ret = vfio_device_open(df, NULL, NULL);
> +/* @pt_id == NULL implies detach */
> +int vfio_iommufd_attach(struct vfio_device *vdev, u32 *pt_id)
> +{
> + lockdep_assert_held(&vdev->dev_set->lock);
> +
> + return vdev->ops->attach_ioas(vdev, pt_id);
> +}
what benefit does this one-line wrapper give actually?
especially pt_id==NULL is checked in the callback instead of in this
wrapper.
