My CPU is Intel T9300, it supports VT-x, but it does not support VT-d. I am using Xen pvops virtualization. I have a PCI device, and my host system can work without it. So I am thinking if it is possible to pass it to my guest vm.
Since version 3.0, Xen has provided PCI passthrough to a paravirtual (PV) guest without VT-d CPU/Motherboard extensions. A PV guest means that the guest is running a special Xen kernel that is aware of the hypervisor. Xen PV guest kernels exist for Linux, NetBSD, FreeBSD, OpenSolaris and Novell Netware operating systems.
Xen cannot provide PCI passthrough to a HVM (fully virtualized) guest without VT-d. An example of an HVM guest would be Windows.
This wiki entry discusses Xen PCI passthrough.