Re: [PATCH v1 17/20] iommu/s390-iommu: Implement s390_iommu_domain_test_device

Niklas Schnelle
2025-10-13T09:59:59Z

On Sun, 2025-10-12 at 17:05 -0700, Nicolin Chen wrote:
> Move sanity and compatibility tests from the attach_dev callback to the
> new test_dev callback function. The IOMMU core makes sure an attach_dev
> call must be invoked after a successful test_dev call.
>
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> ---
> drivers/iommu/s390-iommu.c | 22 +++++++++++++++-------
> 1 file changed, 15 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
> index 366e47978ac07..3c6141a4a1faf 100644
> --- a/drivers/iommu/s390-iommu.c
> +++ b/drivers/iommu/s390-iommu.c
> @@ -694,6 +694,20 @@ static int blocking_domain_attach_device(struct iommu_domain *domain,
> return 0;
> }
>
> +static int s390_iommu_domain_test_device(struct iommu_domain *domain,
> + struct device *dev, ioasid_t pasid,
> + struct iommu_domain *old)
> +{
> + struct zpci_dev *zdev = to_zpci_dev(dev);
> +
> + if (!zdev)
> + return -ENODEV;
> + if (WARN_ON(domain->geometry.aperture_start > zdev->end_dma ||
> + domain->geometry.aperture_end < zdev->start_dma))
> + return -EINVAL;
> + return 0;
> +}
> +
> static int s390_iommu_attach_device(struct iommu_domain *domain,
> struct device *dev,
> struct iommu_domain *old)
> @@ -704,13 +718,6 @@ static int s390_iommu_attach_device(struct iommu_domain *domain,
> u8 status;
> int cc;
>
> - if (!zdev)
> - return -ENODEV;
> -
> - if (WARN_ON(domain->geometry.aperture_start > zdev->end_dma ||
> - domain->geometry.aperture_end < zdev->start_dma))
> - return -EINVAL;
> -
> blocking_domain_attach_device(&blocking_domain, dev);
>
> /* If we fail now DMA remains blocked via blocking domain */
> @@ -1177,6 +1184,7 @@ static struct iommu_domain blocking_domain = {
> .device_group = generic_device_group, \
> .get_resv_regions = s390_iommu_get_resv_regions, \
> .default_domain_ops = &(const struct iommu_domain_ops) { \
> + .test_dev = s390_iommu_domain_test_device, \
> .attach_dev = s390_iommu_attach_device, \
> .map_pages = s390_iommu_map_pages, \
> .unmap_pages = s390_iommu_unmap_pages, \

Looks good to me, thanks!

Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>