PCI devices can make use of a functionality called phantom functions,\nthat when enabled allows the device to generate requests using the IDs\nof functions that are otherwise unpopulated. This allows a device to\nextend the number of outstanding requests.\n\nSuch phantom functions need an IOMMU context setup, but failure to\nsetup the context is not fatal when the device is assigned. Not\nfailing device assignment when such failure happens can lead to the\nprimary device being assigned to a guest, while some of the phantom\nfunctions are assigned to a different domain