[PATCH v6 06/14] iommufd/viommu: Add iommufd_viommu_get_vdev_id helper

[Jason Gunthorpe]

On Fri, Jan 24, 2025 at 04:30:35PM -0800, Nicolin Chen wrote:
> This is a reverse search v.s. iommufd_viommu_find_dev, as drivers may want
> to convert a struct device pointer (physical) to its virtual device ID for
> an event injection to the user space VM.
> 
> Again, this avoids exposing more core structures to the drivers, than the
> iommufd_viommu alone.
> 
> Reviewed-by: Lu Baolu <baolu.lu at linux.intel.com>
> Reviewed-by: Kevin Tian <kevin.tian at intel.com>
> Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>
> ---
>  include/linux/iommufd.h        |  9 +++++++++
>  drivers/iommu/iommufd/driver.c | 24 ++++++++++++++++++++++++
>  2 files changed, 33 insertions(+)

Reviewed-by: Jason Gunthorpe <jgg at nvidia.com>

> +	xa_lock(&viommu->vdevs);
> +	xa_for_each(&viommu->vdevs, index, vdev) {
> +		if (vdev->dev == dev) {
> +			*vdev_id = (unsigned long)vdev->id;

I don't think we need this cast

Jason