[PATCH v6 08/14] iommufd/selftest: Require vdev_id when attaching to a nested domain

[Tian, Kevin]

> From: Nicolin Chen <nicolinc at nvidia.com>
> Sent: Saturday, January 25, 2025 8:31 AM
> 
> When attaching a device to a vIOMMU-based nested domain, vdev_id must
> be
> present. Add a piece of code hard-requesting it, preparing for a vEVENTQ
> support in the following patch. Then, update the TEST_F.
> 
> A HWPT-based nested domain will return a NULL new_viommu, thus no such
> a
> vDEVICE requirement.
> 
> Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>

Reviewed-by: Kevin Tian <kevin.tian at intel.com>