Re: [PATCH v5 11/19] vfio-iommufd: Add detach_ioas support for physical VFIO devices

Jason Gunthorpe
2023-02-27T18:44:56Z

On Mon, Feb 27, 2023 at 03:11:27AM -0800, Yi Liu wrote:
> diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> index c89a047a4cd8..d540cf683d93 100644
> --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
> @@ -594,6 +594,7 @@ static const struct vfio_device_ops vfio_fsl_mc_ops = {
> .bind_iommufd = vfio_iommufd_physical_bind,
> .unbind_iommufd = vfio_iommufd_physical_unbind,
> .attach_ioas = vfio_iommufd_physical_attach_ioas,
> + .detach_ioas = vfio_iommufd_physical_detach_ioas,
> };
>
> static struct fsl_mc_driver vfio_fsl_mc_driver = {
> diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
> index beef6ca21107..bfaa9876499b 100644
> --- a/drivers/vfio/iommufd.c
> +++ b/drivers/vfio/iommufd.c
> @@ -88,6 +88,14 @@ int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
> {
> int rc;
>
> + lockdep_assert_held(&vdev->dev_set->lock);
> +
> + if (!vdev->iommufd_device)
> + return -EINVAL;

This should be a WARN_ON. The vdev->iommufd_ctx should be NULL if it
hasn't been bound, and it can't be bound unless the
iommufd_device/attach was created.

> @@ -96,6 +104,18 @@ int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
> }
> EXPORT_SYMBOL_GPL(vfio_iommufd_physical_attach_ioas);
>
> +void vfio_iommufd_physical_detach_ioas(struct vfio_device *vdev)
> +{
> + lockdep_assert_held(&vdev->dev_set->lock);
> +
> + if (!vdev->iommufd_device || !vdev->iommufd_attached)
> + return;

Same

Jason