copy
//0x18 bytes (sizeof)
struct _EXT_IOMMU_DEVICE_ID
{
    enum _EXT_IOMMU_DEVICE_TYPE DeviceType;                                 //0x0
    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
    };
};