XEN_IOPORT_BASE
#define XEN_IOPORT_PLATFLAGS (XEN_IOPORT_BASE + 0) /* 1 byte access (R/W) */
#define XEN_IOPORT_MAGIC (XEN_IOPORT_BASE + 0) /* 2 byte access (R) */
#define XEN_IOPORT_UNPLUG (XEN_IOPORT_BASE + 0) /* 2 byte access (W) */
#define XEN_IOPORT_DRVVER (XEN_IOPORT_BASE + 0) /* 4 byte access (W) */
#define XEN_IOPORT_SYSLOG (XEN_IOPORT_BASE + 2) /* 1 byte access (W) */
#define XEN_IOPORT_PROTOVER (XEN_IOPORT_BASE + 2) /* 1 byte access (R) */
#define XEN_IOPORT_PRODNUM (XEN_IOPORT_BASE + 2) /* 2 byte access (W) */