An apparatus for operating an input/output (I/O) interface in a virtual machine is provided. The apparatus is configured to: map a first portion of a memory device to a configuration space of an I/O interface; obtain a first mapping table that maps a set of host space virtual addresses to a first set of physical addresses associated with the first portion of the memory device; obtain a second mapping table that maps a second set of physical addresses associated with a second portion of the memory device accessible by a virtual machine to the set of host space virtual addresses; generate a third mapping table that maps the second set of physical addresses to the first set of physical addresses; and provide the third mapping table to a device driver operating in the virtual machine, to enable the device driver to access the configuration space of the I/O interface.