vnd_user
IOCTL_STRUCT_CONV_TO(VNDIOCGET, vnd_user);
struct vnd_user *p, u_long cmd)
netbsd32_from_vnd_user(struct vnd_user *p,
struct vnd_user *vnu = data;
#define VNDIOCGET _IOWR('F', 3, struct vnd_user) /* get list */
struct vnd_user vnu;