ðɪs mˌeɪks pɹəvˈaɪdɪŋ dᵻɹˈɛkt ˈæksɛs tə ðə kəmpjˈuːɾɚ hˈɑːɹdwɛɹ dˈɪfɪkəlt, bɪkˈʌz ɪf ðə ɡˈɛst ˌoʊˈɛs tɹˈaɪd tʊ ɪnstɹˈʌkt ðə hˈɑːɹdwɛɹ tə pɚfˈɔːɹm ɐ dᵻɹˈɛkt mˈɛmɚɹi ˈæksɛs dˌiːˌɛmˈeɪ jˈuːzɪŋ ɡˈɛstfˈɪzɪkəl ɐdɹˈɛsᵻz, ɪt wʊd lˈaɪkli kɚɹˈʌpt ðə mˈɛmɚɹi, æz ðə hˈɑːɹdwɛɹ dʌznˌɑːt nˈoʊ ɐbˌaʊt ðə mˈæpɪŋ bᵻtwˌiːn ðə ɡˈɛstfˈɪzɪkəl ænd hˈoʊstfˈɪzɪkəl ɐdɹˈɛsᵻz fɚðə ɡˈɪvən vˈɜːtʃuːəl məʃˈiːn.
This makes providing direct access to the computer hardware difficult, because if the guest OS tried to instruct the hardware to perform a direct memory access (DMA) using guest-physical addresses, it would likely corrupt the memory, as the hardware does not know about the mapping between the guest-physical and host-physical addresses for the given virtual machine.