tests: is_iommu_supported function
tests: is_iommu_supported function

QubesOS/qubes-issues#4689

marmarek/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin