patch maps the host address to a device address for buffers (including rings, device specifc request and response pointed by vring descriptor, and any further memory reference by those request and response). Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Jordan Justen <jordan.l.justen@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Laszlo Ersek <lersek@redhat.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> [lersek@redhat.com: return EFI_DEVICE_ERROR if mapping fails in GetRNG] Reviewed-by: Laszlo Ersek <lersek@redhat.com> Regression-tested-by: Laszlo Ersek <lersek@redhat.com>