xnu-1504.9.17.tar.gz

[apple/xnu.git] / osfmk / kern / host.c

/*
 * Copyright (c) 2000-2009 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989,1988 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 */

/*
 *      host.c
 *
 *      Non-ipc host functions.
 */

#include <mach/mach_types.h>
#include <mach/boolean.h>
#include <mach/host_info.h>
#include <mach/host_special_ports.h>
#include <mach/kern_return.h>
#include <mach/machine.h>
#include <mach/port.h>
#include <mach/processor_info.h>
#include <mach/vm_param.h>
#include <mach/processor.h>
#include <mach/mach_host_server.h>
#include <mach/host_priv_server.h>
#include <mach/vm_map.h>

#include <kern/kern_types.h>
#include <kern/assert.h>
#include <kern/kalloc.h>
#include <kern/host.h>
#include <kern/host_statistics.h>
#include <kern/ipc_host.h>
#include <kern/misc_protos.h>
#include <kern/sched.h>
#include <kern/processor.h>

#include <vm/vm_map.h>

host_data_t     realhost;

kern_return_t
host_processors(
        host_priv_t                             host_priv,
        processor_array_t               *out_array,
        mach_msg_type_number_t  *countp)
{
        register processor_t    processor, *tp;
        void                                    *addr;
        unsigned int                    count, i;

        if (host_priv == HOST_PRIV_NULL)
                return (KERN_INVALID_ARGUMENT);

        assert(host_priv == &realhost);

        count = processor_count;
        assert(count != 0);

        addr = kalloc((vm_size_t) (count * sizeof(mach_port_t)));
        if (addr == 0)
                return (KERN_RESOURCE_SHORTAGE);

        tp = (processor_t *) addr;
        *tp++ = processor = processor_list;

        if (count > 1) {
                simple_lock(&processor_list_lock);

                for (i = 1; i < count; i++)
                        *tp++ = processor = processor->processor_list;

                simple_unlock(&processor_list_lock);
        }

        *countp = count;
        *out_array = (processor_array_t)addr;

        /* do the conversion that Mig should handle */

        tp = (processor_t *) addr;
        for (i = 0; i < count; i++)
                ((mach_port_t *) tp)[i] =
                      (mach_port_t)convert_processor_to_port(tp[i]);

        return (KERN_SUCCESS);
}

kern_return_t
host_info(
        host_t                                  host,
        host_flavor_t                   flavor,
        host_info_t                             info,
        mach_msg_type_number_t  *count)
{

        if (host == HOST_NULL)
                return (KERN_INVALID_ARGUMENT);
        
        switch (flavor) {

        case HOST_BASIC_INFO:
        {
                register host_basic_info_t      basic_info;
                register int                            master_id;

                /*
                 *      Basic information about this host.
                 */
                if (*count < HOST_BASIC_INFO_OLD_COUNT)
                        return (KERN_FAILURE);

                basic_info = (host_basic_info_t) info;

                basic_info->memory_size = machine_info.memory_size;
                basic_info->max_cpus = machine_info.max_cpus;
                basic_info->avail_cpus = processor_avail_count;
                master_id = master_processor->cpu_id;
                basic_info->cpu_type = slot_type(master_id);
                basic_info->cpu_subtype = slot_subtype(master_id);

                if (*count >= HOST_BASIC_INFO_COUNT) {
                        basic_info->cpu_threadtype = slot_threadtype(master_id);
                        basic_info->physical_cpu = machine_info.physical_cpu;
                        basic_info->physical_cpu_max = machine_info.physical_cpu_max;
                        basic_info->logical_cpu = machine_info.logical_cpu;
                        basic_info->logical_cpu_max = machine_info.logical_cpu_max;
                        basic_info->max_mem = machine_info.max_mem;

                        *count = HOST_BASIC_INFO_COUNT;
                } else {
                        *count = HOST_BASIC_INFO_OLD_COUNT;
                }

                return (KERN_SUCCESS);
        }

        case HOST_SCHED_INFO:
        {
                register host_sched_info_t      sched_info;

                /*
                 *      Return scheduler information.
                 */
                if (*count < HOST_SCHED_INFO_COUNT)
                        return (KERN_FAILURE);

                sched_info = (host_sched_info_t) info;

                sched_info->min_timeout = 
                        sched_info->min_quantum = std_quantum_us / 1000;

                *count = HOST_SCHED_INFO_COUNT;

                return (KERN_SUCCESS);
        }

        case HOST_RESOURCE_SIZES:
        { 
                /*
                 * Return sizes of kernel data structures
                 */
                if (*count < HOST_RESOURCE_SIZES_COUNT)
                        return (KERN_FAILURE);

                /* XXX Fail until ledgers are implemented */
                return (KERN_INVALID_ARGUMENT);
        }
                  
        case HOST_PRIORITY_INFO:
        {
                register host_priority_info_t   priority_info;

                if (*count < HOST_PRIORITY_INFO_COUNT)
                        return (KERN_FAILURE);

                priority_info = (host_priority_info_t) info;

                priority_info->kernel_priority  = MINPRI_KERNEL;
                priority_info->system_priority  = MINPRI_KERNEL;
                priority_info->server_priority  = MINPRI_RESERVED;
                priority_info->user_priority    = BASEPRI_DEFAULT;
                priority_info->depress_priority = DEPRESSPRI;
                priority_info->idle_priority    = IDLEPRI;
                priority_info->minimum_priority = MINPRI_USER;
                priority_info->maximum_priority = MAXPRI_RESERVED;

                *count = HOST_PRIORITY_INFO_COUNT;

                return (KERN_SUCCESS);
        }

        /*
         * Gestalt for various trap facilities.
         */
        case HOST_MACH_MSG_TRAP:
        case HOST_SEMAPHORE_TRAPS:
        {
                *count = 0;
                return (KERN_SUCCESS);
        }

        default:
                return (KERN_INVALID_ARGUMENT);
        }
}

kern_return_t
host_statistics(
        host_t                                  host,
        host_flavor_t                   flavor,
        host_info_t                             info,
        mach_msg_type_number_t  *count)
{
        uint32_t        i;

        if (host == HOST_NULL)
                return (KERN_INVALID_HOST);
        
        switch(flavor) {

        case HOST_LOAD_INFO:
        {
                host_load_info_t        load_info;

                if (*count < HOST_LOAD_INFO_COUNT)
                        return (KERN_FAILURE);

                load_info = (host_load_info_t) info;

                bcopy((char *) avenrun,
                          (char *) load_info->avenrun, sizeof avenrun);
                bcopy((char *) mach_factor,
                          (char *) load_info->mach_factor, sizeof mach_factor);

                *count = HOST_LOAD_INFO_COUNT;
                return (KERN_SUCCESS);
        }

        case HOST_VM_INFO:
        {
                register processor_t            processor;
                register vm_statistics64_t      stat;
                vm_statistics64_data_t          host_vm_stat;
                vm_statistics_t                 stat32;
                mach_msg_type_number_t          original_count;
                
                if (*count < HOST_VM_INFO_REV0_COUNT)
                        return (KERN_FAILURE);

                processor = processor_list;
                stat = &PROCESSOR_DATA(processor, vm_stat);
                host_vm_stat = *stat;

                if (processor_count > 1) {
                        simple_lock(&processor_list_lock);

                        while ((processor = processor->processor_list) != NULL) {
                                stat = &PROCESSOR_DATA(processor, vm_stat);

                                host_vm_stat.zero_fill_count += stat->zero_fill_count;
                                host_vm_stat.reactivations += stat->reactivations;
                                host_vm_stat.pageins += stat->pageins;
                                host_vm_stat.pageouts += stat->pageouts;
                                host_vm_stat.faults += stat->faults;
                                host_vm_stat.cow_faults += stat->cow_faults;
                                host_vm_stat.lookups += stat->lookups;
                                host_vm_stat.hits += stat->hits;
                        }

                        simple_unlock(&processor_list_lock);
                }

                stat32 = (vm_statistics_t) info;

                stat32->free_count = VM_STATISTICS_TRUNCATE_TO_32_BIT(vm_page_free_count + vm_page_speculative_count);
                stat32->active_count = VM_STATISTICS_TRUNCATE_TO_32_BIT(vm_page_active_count);
                
                if (vm_page_local_q) {
                        for (i = 0; i < vm_page_local_q_count; i++) {
                                struct vpl      *lq;

                                lq = &vm_page_local_q[i].vpl_un.vpl;

                                stat32->active_count += VM_STATISTICS_TRUNCATE_TO_32_BIT(lq->vpl_count);
                        }
                }
                stat32->inactive_count = VM_STATISTICS_TRUNCATE_TO_32_BIT(vm_page_inactive_count);
#if CONFIG_EMBEDDED
                stat32->wire_count = VM_STATISTICS_TRUNCATE_TO_32_BIT(vm_page_wire_count);
#else
                stat32->wire_count = VM_STATISTICS_TRUNCATE_TO_32_BIT(vm_page_wire_count + vm_page_throttled_count + vm_lopage_free_count);
#endif
                stat32->zero_fill_count = VM_STATISTICS_TRUNCATE_TO_32_BIT(host_vm_stat.zero_fill_count);
                stat32->reactivations = VM_STATISTICS_TRUNCATE_TO_32_BIT(host_vm_stat.reactivations);
                stat32->pageins = VM_STATISTICS_TRUNCATE_TO_32_BIT(host_vm_stat.pageins);
                stat32->pageouts = VM_STATISTICS_TRUNCATE_TO_32_BIT(host_vm_stat.pageouts);
                stat32->faults = VM_STATISTICS_TRUNCATE_TO_32_BIT(host_vm_stat.faults);
                stat32->cow_faults = VM_STATISTICS_TRUNCATE_TO_32_BIT(host_vm_stat.cow_faults);
                stat32->lookups = VM_STATISTICS_TRUNCATE_TO_32_BIT(host_vm_stat.lookups);
                stat32->hits = VM_STATISTICS_TRUNCATE_TO_32_BIT(host_vm_stat.hits);

                /*
                 * Fill in extra info added in later revisions of the
                 * vm_statistics data structure.  Fill in only what can fit
                 * in the data structure the caller gave us !
                 */
                original_count = *count;
                *count = HOST_VM_INFO_REV0_COUNT; /* rev0 already filled in */
                if (original_count >= HOST_VM_INFO_REV1_COUNT) {
                        /* rev1 added "purgeable" info */
                        stat32->purgeable_count = VM_STATISTICS_TRUNCATE_TO_32_BIT(vm_page_purgeable_count);
                        stat32->purges = VM_STATISTICS_TRUNCATE_TO_32_BIT(vm_page_purged_count);
                        *count = HOST_VM_INFO_REV1_COUNT;
                }

                if (original_count >= HOST_VM_INFO_REV2_COUNT) {
                        /* rev2 added "speculative" info */
                        stat32->speculative_count = VM_STATISTICS_TRUNCATE_TO_32_BIT(vm_page_speculative_count);
                        *count = HOST_VM_INFO_REV2_COUNT;
                }

                /* rev3 changed some of the fields to be 64-bit*/

                return (KERN_SUCCESS);
        }
                
        case HOST_CPU_LOAD_INFO:
        {
                register processor_t    processor;
                host_cpu_load_info_t    cpu_load_info;

                if (*count < HOST_CPU_LOAD_INFO_COUNT)
                        return (KERN_FAILURE);

#define GET_TICKS_VALUE(processor, state, timer)                         \
MACRO_BEGIN                                                              \
        cpu_load_info->cpu_ticks[(state)] +=                             \
                (uint32_t)(timer_grab(&PROCESSOR_DATA(processor, timer)) \
                                / hz_tick_interval);                     \
MACRO_END

                cpu_load_info = (host_cpu_load_info_t)info;
                cpu_load_info->cpu_ticks[CPU_STATE_USER] = 0;
                cpu_load_info->cpu_ticks[CPU_STATE_SYSTEM] = 0;
                cpu_load_info->cpu_ticks[CPU_STATE_IDLE] = 0;
                cpu_load_info->cpu_ticks[CPU_STATE_NICE] = 0;

                processor = processor_list;
                GET_TICKS_VALUE(processor, CPU_STATE_USER, user_state);
                GET_TICKS_VALUE(processor, CPU_STATE_SYSTEM, system_state);
                GET_TICKS_VALUE(processor, CPU_STATE_IDLE, idle_state);

                if (processor_count > 1) {
                        simple_lock(&processor_list_lock);

                        while ((processor = processor->processor_list) != NULL) {
                                GET_TICKS_VALUE(processor, CPU_STATE_USER, user_state);
                                GET_TICKS_VALUE(processor, CPU_STATE_SYSTEM, system_state);
                                GET_TICKS_VALUE(processor, CPU_STATE_IDLE, idle_state);
                        }

                        simple_unlock(&processor_list_lock);
                }

                *count = HOST_CPU_LOAD_INFO_COUNT;

                return (KERN_SUCCESS);
        }

        default:
                return (KERN_INVALID_ARGUMENT);
        }
}


kern_return_t
host_statistics64(
        host_t                          host,
        host_flavor_t                   flavor,
        host_info64_t                   info,
        mach_msg_type_number_t          *count)
{
        uint32_t        i;
        
        if (host == HOST_NULL)
                return (KERN_INVALID_HOST);
        
        switch(flavor) {

                case HOST_VM_INFO64: /* We were asked to get vm_statistics64 */
                {
                        register processor_t            processor;
                        register vm_statistics64_t      stat;
                        vm_statistics64_data_t          host_vm_stat;

                        if (*count < HOST_VM_INFO64_COUNT)
                                return (KERN_FAILURE);

                        processor = processor_list;
                        stat = &PROCESSOR_DATA(processor, vm_stat);
                        host_vm_stat = *stat;

                        if (processor_count > 1) {
                                simple_lock(&processor_list_lock);

                                while ((processor = processor->processor_list) != NULL) {
                                        stat = &PROCESSOR_DATA(processor, vm_stat);

                                        host_vm_stat.zero_fill_count += stat->zero_fill_count;
                                        host_vm_stat.reactivations += stat->reactivations;
                                        host_vm_stat.pageins += stat->pageins;
                                        host_vm_stat.pageouts += stat->pageouts;
                                        host_vm_stat.faults += stat->faults;
                                        host_vm_stat.cow_faults += stat->cow_faults;
                                        host_vm_stat.lookups += stat->lookups;
                                        host_vm_stat.hits += stat->hits;
                                }

                                simple_unlock(&processor_list_lock);
                        }

                        stat = (vm_statistics64_t) info;

                        stat->free_count = vm_page_free_count + vm_page_speculative_count;
                        stat->active_count = vm_page_active_count;

                        if (vm_page_local_q) {
                                for (i = 0; i < vm_page_local_q_count; i++) {
                                        struct vpl      *lq;
                                
                                        lq = &vm_page_local_q[i].vpl_un.vpl;

                                        stat->active_count += lq->vpl_count;
                                }
                        }
                        stat->inactive_count = vm_page_inactive_count;
#if CONFIG_EMBEDDED
                        stat->wire_count = vm_page_wire_count;
#else
                        stat->wire_count = vm_page_wire_count + vm_page_throttled_count + vm_lopage_free_count;
#endif
                        stat->zero_fill_count = host_vm_stat.zero_fill_count;
                        stat->reactivations = host_vm_stat.reactivations;
                        stat->pageins = host_vm_stat.pageins;
                        stat->pageouts = host_vm_stat.pageouts;
                        stat->faults = host_vm_stat.faults;
                        stat->cow_faults = host_vm_stat.cow_faults;
                        stat->lookups = host_vm_stat.lookups;
                        stat->hits = host_vm_stat.hits;
                
                        /* rev1 added "purgable" info */
                        stat->purgeable_count = vm_page_purgeable_count;
                        stat->purges = vm_page_purged_count;
                
                        /* rev2 added "speculative" info */
                        stat->speculative_count = vm_page_speculative_count;

                        *count = HOST_VM_INFO64_COUNT;  

                        return(KERN_SUCCESS);
                }

                default: /* If we didn't recognize the flavor, send to host_statistics */
                        return(host_statistics(host, flavor, (host_info_t) info, count)); 
        }
}


/*
 * Get host statistics that require privilege.
 * None for now, just call the un-privileged version.
 */
kern_return_t
host_priv_statistics(
        host_priv_t             host_priv,
        host_flavor_t           flavor,
        host_info_t             info,
        mach_msg_type_number_t  *count)
{
        return(host_statistics((host_t)host_priv, flavor, info, count));
}

kern_return_t
host_page_size(
        host_t          host,
        vm_size_t       *out_page_size)
{
        if (host == HOST_NULL)
                return(KERN_INVALID_ARGUMENT);

        *out_page_size = PAGE_SIZE;

        return(KERN_SUCCESS);
}

/*
 *      Return kernel version string (more than you ever
 *      wanted to know about what version of the kernel this is).
 */
extern char     version[];

kern_return_t
host_kernel_version(
        host_t                  host,
        kernel_version_t        out_version)
{

        if (host == HOST_NULL)
                return(KERN_INVALID_ARGUMENT);

        (void) strncpy(out_version, version, sizeof(kernel_version_t));

        return(KERN_SUCCESS);
}

/*
 *      host_processor_sets:
 *
 *      List all processor sets on the host.
 */
kern_return_t
host_processor_sets(
        host_priv_t                     host_priv,
        processor_set_name_array_t      *pset_list,
        mach_msg_type_number_t          *count)
{
        void *addr;

        if (host_priv == HOST_PRIV_NULL)
                return (KERN_INVALID_ARGUMENT);

        /*
         *      Allocate memory.  Can be pageable because it won't be
         *      touched while holding a lock.
         */

        addr = kalloc((vm_size_t) sizeof(mach_port_t));
        if (addr == 0)
                return (KERN_RESOURCE_SHORTAGE);

        /* do the conversion that Mig should handle */
        *((ipc_port_t *) addr) = convert_pset_name_to_port(&pset0);

        *pset_list = (processor_set_array_t)addr;
        *count = 1;

        return (KERN_SUCCESS);
}

/*
 *      host_processor_set_priv:
 *
 *      Return control port for given processor set.
 */
kern_return_t
host_processor_set_priv(
        host_priv_t     host_priv,
        processor_set_t pset_name,
        processor_set_t *pset)
{
    if (host_priv == HOST_PRIV_NULL || pset_name == PROCESSOR_SET_NULL) {
                *pset = PROCESSOR_SET_NULL;

                return (KERN_INVALID_ARGUMENT);
    }

    *pset = pset_name;

    return (KERN_SUCCESS);
}

/*
 *      host_processor_info
 *
 *      Return info about the processors on this host.  It will return
 *      the number of processors, and the specific type of info requested
 *      in an OOL array.
 */
kern_return_t
host_processor_info(
        host_t                                  host,
        processor_flavor_t              flavor,
        natural_t                               *out_pcount,
        processor_info_array_t  *out_array,
        mach_msg_type_number_t  *out_array_count)
{
        kern_return_t                   result;
        processor_t                             processor;
        host_t                                  thost;
        processor_info_t                info;
        unsigned int                    icount, tcount;
        unsigned int                    pcount, i;
        vm_offset_t                             addr;
        vm_size_t                               size, needed;
        vm_map_copy_t                   copy;

        if (host == HOST_NULL)
                return (KERN_INVALID_ARGUMENT);

        result = processor_info_count(flavor, &icount);
        if (result != KERN_SUCCESS)
                return (result);

        pcount = processor_count;
        assert(pcount != 0);

        needed = pcount * icount * sizeof(natural_t);
        size = round_page(needed);
        result = kmem_alloc(ipc_kernel_map, &addr, size);
        if (result != KERN_SUCCESS)
                return (KERN_RESOURCE_SHORTAGE);

        info = (processor_info_t) addr;
        processor = processor_list;
        tcount = icount;

        result = processor_info(processor, flavor, &thost, info, &tcount);
        if (result != KERN_SUCCESS) {
                kmem_free(ipc_kernel_map, addr, size);
                return (result);
        }

        if (pcount > 1) {
                for (i = 1; i < pcount; i++) {
                        simple_lock(&processor_list_lock);
                        processor = processor->processor_list;
                        simple_unlock(&processor_list_lock);

                        info += icount;
                        tcount = icount;
                        result = processor_info(processor, flavor, &thost, info, &tcount);
                        if (result != KERN_SUCCESS) {
                                kmem_free(ipc_kernel_map, addr, size);
                                return (result);
                        }
                }
        }

        if (size != needed) 
                bzero((char *) addr + needed, size - needed);

        result = vm_map_unwire(ipc_kernel_map, vm_map_trunc_page(addr),
                               vm_map_round_page(addr + size), FALSE);
        assert(result == KERN_SUCCESS);
        result = vm_map_copyin(ipc_kernel_map, (vm_map_address_t)addr,
                               (vm_map_size_t)size, TRUE, &copy);
        assert(result == KERN_SUCCESS);

        *out_pcount = pcount;
        *out_array = (processor_info_array_t) copy;
        *out_array_count = pcount * icount;

        return (KERN_SUCCESS);
}

/*
 *      Kernel interface for setting a special port.
 */
kern_return_t
kernel_set_special_port(
        host_priv_t     host_priv,              
        int             id,
        ipc_port_t      port)
{
        ipc_port_t old_port;

        host_lock(host_priv);
        old_port = host_priv->special[id];
        host_priv->special[id] = port;
        host_unlock(host_priv);
        if (IP_VALID(old_port))
                ipc_port_release_send(old_port);
        return KERN_SUCCESS;
}

/*
 *      User interface for setting a special port.
 *
 *      Only permits the user to set a user-owned special port
 *      ID, rejecting a kernel-owned special port ID.
 *
 *      A special kernel port cannot be set up using this
 *      routine; use kernel_set_special_port() instead.
 */
kern_return_t
host_set_special_port(
        host_priv_t     host_priv,
        int             id,
        ipc_port_t      port)
{
        if (host_priv == HOST_PRIV_NULL ||
            id <= HOST_MAX_SPECIAL_KERNEL_PORT || id > HOST_MAX_SPECIAL_PORT ) {
                if (IP_VALID(port))
                        ipc_port_release_send(port);
                return KERN_INVALID_ARGUMENT;
        }

        return kernel_set_special_port(host_priv, id, port);
}


/*
 *      User interface for retrieving a special port.
 *
 *      Note that there is nothing to prevent a user special
 *      port from disappearing after it has been discovered by
 *      the caller; thus, using a special port can always result
 *      in a "port not valid" error.
 */

kern_return_t
host_get_special_port(
        host_priv_t     host_priv,
        __unused int    node,
        int             id,
        ipc_port_t      *portp)
{
        ipc_port_t      port;

        if (host_priv == HOST_PRIV_NULL ||
            id == HOST_SECURITY_PORT || id > HOST_MAX_SPECIAL_PORT || id < 0)
                return KERN_INVALID_ARGUMENT;

        host_lock(host_priv);
        port = realhost.special[id];
        *portp = ipc_port_copy_send(port);
        host_unlock(host_priv);

        return KERN_SUCCESS;
}


/*
 *      host_get_io_master
 *
 *      Return the IO master access port for this host.
 */
kern_return_t
host_get_io_master(
        host_t host,
        io_master_t *io_masterp)
{
        if (host == HOST_NULL)
                return KERN_INVALID_ARGUMENT;

        return (host_get_io_master_port(host_priv_self(), io_masterp));
}

host_t
host_self(void)
{
  return &realhost;
}

host_priv_t
host_priv_self(void)
{
  return &realhost;
}

host_security_t
host_security_self(void)
{
  return &realhost;
}