[libvirt] Question about pci-passthrough

Hello All, I had a question about pci-passthrough using hostdev mode in Libvirt. When I assign hostdev->parent.type = VIR_DOMAIN_DEVICE_NET, the hostdev is passed into the guest and acts as a network device. When I assign hostdev->parent.type = VIR_DOMAIN_DEVICE_NONE, the hostdev is passed into the guest and acts as a PCI Host device. Please can someone point me to the part of code in libvirt where this decision is made based on hostdev->parent.type? -- Many Thanks, Regards, Shradha Shah