XEN_SYSCTL_INTERFACE_VERSION
op.interface_version = XEN_SYSCTL_INTERFACE_VERSION;
xs.interface_version = XEN_SYSCTL_INTERFACE_VERSION;
if (op.interface_version != XEN_SYSCTL_INTERFACE_VERSION) {
dop.interface_version = XEN_SYSCTL_INTERFACE_VERSION;
dop.interface_version = XEN_SYSCTL_INTERFACE_VERSION;
XEN_SYSCTL_INTERFACE_VERSION;
op.interface_version = XEN_SYSCTL_INTERFACE_VERSION;