//0x18 bytes (sizeof)
struct _EXT_IOMMU_DEVICE_ID
{
enum _EXT_IOMMU_DEVICE_TYPE DeviceType; //0x0
union _EXT_IOMMU_DEVICE_ID_FLAGS Flags; //0x4
union
{
struct _EXT_IOMMU_DEVICE_ID_PCI Pci; //0x8
struct _EXT_IOMMU_DEVICE_ID_ACPI Acpi; //0x8
UCHAR IoApicId; //0x8
ULONGLONG LogicalId; //0x8
struct _EXT_IOMMU_DEVICE_ID_TEST Test; //0x8
struct _EXT_IOMMU_DEVICE_ID_GIC Gic; //0x8
};
};