lspci 找出裝置代號，以下假設為 0000:07:00.0

readlink /sys/bus/pci/devices/0000:07:00.0/driver 找出 Dom0 使用的驅動程式，
以下假設為 ../../../../bus/pci/drivers/xhci_hcd


停用原先的驅動程式
    echo "0000:07:00.0" > /sys/bus/pci/drivers/xhci_hcd/unbind

載入核心模組
    modprobe xen-pciback passthrough=1

將裝置交由 xen-pciback 管理
    echo "0000:07:00.0" > /sys/bus/pci/drivers/pciback/new_slot
    echo "0000:07:00.0" > /sys/bus/pci/drivers/pciback/bind

檢查是否已經可以使用
    xl pci-list-assignable-devices

連接至 Domain U
    xl pci-attach domU 0000:07:00.0

=============================================================================

從 Domain U 斷線
    xl pci-detach domU 0000:07:00.0

檢查是否已經可以使用
    xl pci-list-assignable-devices

從 xen-pciback 取回
    echo "0000:07:00.0" > /sys/bus/pci/drivers/pciback/unbind
    echo "0000:07:00.0" > /sys/bus/pci/drivers/pciback/remove_slot

回歸原先的驅動程式
    echo "0000:07:00.0" > /sys/bus/pci/drivers/xhci_hcd/bind