Archipelago » qemu

/*

 * QEMU System Emulator

 *

 * Copyright (c) 2003-2008 Fabrice Bellard

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include <stdint.h>

#include <stdarg.h>

#include <stdlib.h>

#ifndef _WIN32

#include <sys/types.h>

#include <sys/mman.h>

#endif

#include "config.h"

#include "monitor/monitor.h"

#include "sysemu/sysemu.h"

#include "qemu/bitops.h"

#include "qemu/bitmap.h"

#include "sysemu/arch_init.h"

#include "audio/audio.h"

#include "hw/pc.h"

#include "hw/pci/pci.h"

#include "hw/audiodev.h"

#include "sysemu/kvm.h"

#include "migration/migration.h"

#include "exec/gdbstub.h"

#include "hw/smbios.h"

#include "exec/address-spaces.h"

#include "hw/pcspk.h"

#include "migration/page_cache.h"

#include "qemu/config-file.h"

#include "qmp-commands.h"

#include "trace.h"

#include "exec/cpu-all.h"

#ifdef DEBUG_ARCH_INIT

#define DPRINTF(fmt, ...) \

    do { fprintf(stdout, "arch_init: " fmt, ## __VA_ARGS__); } while (0)

#else

#define DPRINTF(fmt, ...) \

    do { } while (0)

#endif

#ifdef TARGET_SPARC

int graphic_width = 1024;

int graphic_height = 768;

int graphic_depth = 8;

#else

int graphic_width = 800;

int graphic_height = 600;

int graphic_depth = 15;

#endif

#if defined(TARGET_ALPHA)

#define QEMU_ARCH QEMU_ARCH_ALPHA

#elif defined(TARGET_ARM)

#define QEMU_ARCH QEMU_ARCH_ARM

#elif defined(TARGET_CRIS)

#define QEMU_ARCH QEMU_ARCH_CRIS

#elif defined(TARGET_I386)

#define QEMU_ARCH QEMU_ARCH_I386

#elif defined(TARGET_M68K)

#define QEMU_ARCH QEMU_ARCH_M68K

#elif defined(TARGET_LM32)

#define QEMU_ARCH QEMU_ARCH_LM32

#elif defined(TARGET_MICROBLAZE)

#define QEMU_ARCH QEMU_ARCH_MICROBLAZE

#elif defined(TARGET_MIPS)

#define QEMU_ARCH QEMU_ARCH_MIPS

#elif defined(TARGET_OPENRISC)

#define QEMU_ARCH QEMU_ARCH_OPENRISC

#elif defined(TARGET_PPC)

#define QEMU_ARCH QEMU_ARCH_PPC

#elif defined(TARGET_S390X)

#define QEMU_ARCH QEMU_ARCH_S390X

#elif defined(TARGET_SH4)

#define QEMU_ARCH QEMU_ARCH_SH4

#elif defined(TARGET_SPARC)

#define QEMU_ARCH QEMU_ARCH_SPARC

#elif defined(TARGET_XTENSA)

#define QEMU_ARCH QEMU_ARCH_XTENSA

#elif defined(TARGET_UNICORE32)

#define QEMU_ARCH QEMU_ARCH_UNICORE32

#endif

const uint32_t arch_type = QEMU_ARCH;

/***********************************************************/

/* ram save/restore */

#define RAM_SAVE_FLAG_FULL     0x01 /* Obsolete, not used anymore */

#define RAM_SAVE_FLAG_COMPRESS 0x02

#define RAM_SAVE_FLAG_MEM_SIZE 0x04

#define RAM_SAVE_FLAG_PAGE     0x08

#define RAM_SAVE_FLAG_EOS      0x10

#define RAM_SAVE_FLAG_CONTINUE 0x20

#define RAM_SAVE_FLAG_XBZRLE   0x40

#ifdef __ALTIVEC__

#include <altivec.h>

#define VECTYPE        vector unsigned char

#define SPLAT(p)       vec_splat(vec_ld(0, p), 0)

#define ALL_EQ(v1, v2) vec_all_eq(v1, v2)

/* altivec.h may redefine the bool macro as vector type.

 * Reset it to POSIX semantics. */

#undef bool

#define bool _Bool

#elif defined __SSE2__

#include <emmintrin.h>

#define VECTYPE        __m128i

#define SPLAT(p)       _mm_set1_epi8(*(p))

#define ALL_EQ(v1, v2) (_mm_movemask_epi8(_mm_cmpeq_epi8(v1, v2)) == 0xFFFF)

#else

#define VECTYPE        unsigned long

#define SPLAT(p)       (*(p) * (~0UL / 255))

#define ALL_EQ(v1, v2) ((v1) == (v2))

#endif

static struct defconfig_file {

    const char *filename;

    /* Indicates it is an user config file (disabled by -no-user-config) */

    bool userconfig;

} default_config_files[] = {

    { CONFIG_QEMU_CONFDIR "/qemu.conf",                   true },

    { CONFIG_QEMU_CONFDIR "/target-" TARGET_ARCH ".conf", true },

    { NULL }, /* end of list */

};

int qemu_read_default_config_files(bool userconfig)

{

    int ret;

    struct defconfig_file *f;

    for (f = default_config_files; f->filename; f++) {

        if (!userconfig && f->userconfig) {

            continue;

        }

        ret = qemu_read_config_file(f->filename);

        if (ret < 0 && ret != -ENOENT) {

            return ret;

        }

    }

    return 0;

}

static int is_dup_page(uint8_t *page)

{

    VECTYPE *p = (VECTYPE *)page;

    VECTYPE val = SPLAT(page);

    int i;

    for (i = 0; i < TARGET_PAGE_SIZE / sizeof(VECTYPE); i++) {

        if (!ALL_EQ(val, p[i])) {

            return 0;

        }

    }

    return 1;

}

/* struct contains XBZRLE cache and a static page

   used by the compression */

static struct {

    /* buffer used for XBZRLE encoding */

    uint8_t *encoded_buf;

    /* buffer for storing page content */

    uint8_t *current_buf;

    /* buffer used for XBZRLE decoding */

    uint8_t *decoded_buf;

    /* Cache for XBZRLE */

    PageCache *cache;

} XBZRLE = {

    .encoded_buf = NULL,

    .current_buf = NULL,

    .decoded_buf = NULL,

    .cache = NULL,

};

int64_t xbzrle_cache_resize(int64_t new_size)

{

    if (XBZRLE.cache != NULL) {

        return cache_resize(XBZRLE.cache, new_size / TARGET_PAGE_SIZE) *

            TARGET_PAGE_SIZE;

    }

    return pow2floor(new_size);

}

/* accounting for migration statistics */

typedef struct AccountingInfo {

    uint64_t dup_pages;

    uint64_t norm_pages;

    uint64_t iterations;

    uint64_t xbzrle_bytes;

    uint64_t xbzrle_pages;

    uint64_t xbzrle_cache_miss;

    uint64_t xbzrle_overflows;

} AccountingInfo;

static AccountingInfo acct_info;

static void acct_clear(void)

{

    memset(&acct_info, 0, sizeof(acct_info));

}

uint64_t dup_mig_bytes_transferred(void)

{

    return acct_info.dup_pages * TARGET_PAGE_SIZE;

}

uint64_t dup_mig_pages_transferred(void)

{

    return acct_info.dup_pages;

}

uint64_t norm_mig_bytes_transferred(void)

{

    return acct_info.norm_pages * TARGET_PAGE_SIZE;

}

uint64_t norm_mig_pages_transferred(void)

{

    return acct_info.norm_pages;

}

uint64_t xbzrle_mig_bytes_transferred(void)

{

    return acct_info.xbzrle_bytes;

}

uint64_t xbzrle_mig_pages_transferred(void)

{

    return acct_info.xbzrle_pages;

}

uint64_t xbzrle_mig_pages_cache_miss(void)

{

    return acct_info.xbzrle_cache_miss;

}

uint64_t xbzrle_mig_pages_overflow(void)

{

    return acct_info.xbzrle_overflows;

}

static void save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,

        int cont, int flag)

{

        qemu_put_be64(f, offset | cont | flag);

        if (!cont) {

                qemu_put_byte(f, strlen(block->idstr));

                qemu_put_buffer(f, (uint8_t *)block->idstr,

                                strlen(block->idstr));

        }

}

#define ENCODING_FLAG_XBZRLE 0x1

static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,

                            ram_addr_t current_addr, RAMBlock *block,

                            ram_addr_t offset, int cont, bool last_stage)

{

    int encoded_len = 0, bytes_sent = -1;

    uint8_t *prev_cached_page;

    if (!cache_is_cached(XBZRLE.cache, current_addr)) {

        if (!last_stage) {

            cache_insert(XBZRLE.cache, current_addr,

                         g_memdup(current_data, TARGET_PAGE_SIZE));

        }

        acct_info.xbzrle_cache_miss++;

        return -1;

    }

    prev_cached_page = get_cached_data(XBZRLE.cache, current_addr);

    /* save current buffer into memory */

    memcpy(XBZRLE.current_buf, current_data, TARGET_PAGE_SIZE);

    /* XBZRLE encoding (if there is no overflow) */

    encoded_len = xbzrle_encode_buffer(prev_cached_page, XBZRLE.current_buf,

                                       TARGET_PAGE_SIZE, XBZRLE.encoded_buf,

                                       TARGET_PAGE_SIZE);

    if (encoded_len == 0) {

        DPRINTF("Skipping unmodified page\n");

        return 0;

    } else if (encoded_len == -1) {

        DPRINTF("Overflow\n");

        acct_info.xbzrle_overflows++;

        /* update data in the cache */

        memcpy(prev_cached_page, current_data, TARGET_PAGE_SIZE);

        return -1;

    }

    /* we need to update the data in the cache, in order to get the same data */

    if (!last_stage) {

        memcpy(prev_cached_page, XBZRLE.current_buf, TARGET_PAGE_SIZE);

    }

    /* Send XBZRLE based compressed page */

    save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_XBZRLE);

    qemu_put_byte(f, ENCODING_FLAG_XBZRLE);

    qemu_put_be16(f, encoded_len);

    qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len);

    bytes_sent = encoded_len + 1 + 2;

    acct_info.xbzrle_pages++;

    acct_info.xbzrle_bytes += bytes_sent;

    return bytes_sent;

}

static RAMBlock *last_block;

static ram_addr_t last_offset;

static unsigned long *migration_bitmap;

static uint64_t migration_dirty_pages;

static uint32_t last_version;

static inline bool migration_bitmap_test_and_reset_dirty(MemoryRegion *mr,

                                                         ram_addr_t offset)

{

    bool ret;

    int nr = (mr->ram_addr + offset) >> TARGET_PAGE_BITS;

    ret = test_and_clear_bit(nr, migration_bitmap);

    if (ret) {

        migration_dirty_pages--;

    }

    return ret;

}

static inline bool migration_bitmap_set_dirty(MemoryRegion *mr,

                                              ram_addr_t offset)

{

    bool ret;

    int nr = (mr->ram_addr + offset) >> TARGET_PAGE_BITS;

    ret = test_and_set_bit(nr, migration_bitmap);

    if (!ret) {

        migration_dirty_pages++;

    }

    return ret;

}

static void migration_bitmap_sync(void)

{

    RAMBlock *block;

    ram_addr_t addr;

    uint64_t num_dirty_pages_init = migration_dirty_pages;

    MigrationState *s = migrate_get_current();

    static int64_t start_time;

    static int64_t num_dirty_pages_period;

    int64_t end_time;

    if (!start_time) {

        start_time = qemu_get_clock_ms(rt_clock);

    }

    trace_migration_bitmap_sync_start();

    memory_global_sync_dirty_bitmap(get_system_memory());

    QTAILQ_FOREACH(block, &ram_list.blocks, next) {

        for (addr = 0; addr < block->length; addr += TARGET_PAGE_SIZE) {

            if (memory_region_get_dirty(block->mr, addr, TARGET_PAGE_SIZE,

                                        DIRTY_MEMORY_MIGRATION)) {

                migration_bitmap_set_dirty(block->mr, addr);

            }

        }

        memory_region_reset_dirty(block->mr, 0, block->length,

                                  DIRTY_MEMORY_MIGRATION);

    }

    trace_migration_bitmap_sync_end(migration_dirty_pages

                                    - num_dirty_pages_init);

    num_dirty_pages_period += migration_dirty_pages - num_dirty_pages_init;

    end_time = qemu_get_clock_ms(rt_clock);

    /* more than 1 second = 1000 millisecons */

    if (end_time > start_time + 1000) {

        s->dirty_pages_rate = num_dirty_pages_period * 1000

            / (end_time - start_time);

        start_time = end_time;

        num_dirty_pages_period = 0;

    }

}

/*

 * ram_save_block: Writes a page of memory to the stream f

 *

 * Returns:  0: if the page hasn't changed

 *          -1: if there are no more dirty pages

 *           n: the amount of bytes written in other case

 */

static int ram_save_block(QEMUFile *f, bool last_stage)

{

    RAMBlock *block = last_block;

    ram_addr_t offset = last_offset;

    int bytes_sent = -1;

    MemoryRegion *mr;

    ram_addr_t current_addr;

    if (!block)

        block = QTAILQ_FIRST(&ram_list.blocks);

    do {

        mr = block->mr;

        if (migration_bitmap_test_and_reset_dirty(mr, offset)) {

            uint8_t *p;

            int cont = (block == last_block) ? RAM_SAVE_FLAG_CONTINUE : 0;

            p = memory_region_get_ram_ptr(mr) + offset;

            if (is_dup_page(p)) {

                acct_info.dup_pages++;

                save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_COMPRESS);

                qemu_put_byte(f, *p);

                bytes_sent = 1;

            } else if (migrate_use_xbzrle()) {

                current_addr = block->offset + offset;

                bytes_sent = save_xbzrle_page(f, p, current_addr, block,

                                              offset, cont, last_stage);

                if (!last_stage) {

                    p = get_cached_data(XBZRLE.cache, current_addr);

                }

            }

            /* either we didn't send yet (we may have had XBZRLE overflow) */

            if (bytes_sent == -1) {

                save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_PAGE);

                qemu_put_buffer(f, p, TARGET_PAGE_SIZE);

                bytes_sent = TARGET_PAGE_SIZE;

                acct_info.norm_pages++;

            }

            /* if page is unmodified, continue to the next */

            if (bytes_sent != 0) {

                break;

            }

        }

        offset += TARGET_PAGE_SIZE;

        if (offset >= block->length) {

            offset = 0;

            block = QTAILQ_NEXT(block, next);

            if (!block)

                block = QTAILQ_FIRST(&ram_list.blocks);

        }

    } while (block != last_block || offset != last_offset);

    last_block = block;

    last_offset = offset;

    return bytes_sent;

}

static uint64_t bytes_transferred;

static ram_addr_t ram_save_remaining(void)

{

    return migration_dirty_pages;

}

uint64_t ram_bytes_remaining(void)

{

    return ram_save_remaining() * TARGET_PAGE_SIZE;

}

uint64_t ram_bytes_transferred(void)

{

    return bytes_transferred;

}

uint64_t ram_bytes_total(void)

{

    RAMBlock *block;

    uint64_t total = 0;

    QTAILQ_FOREACH(block, &ram_list.blocks, next)

        total += block->length;

    return total;

}

static void migration_end(void)

{

    if (migration_bitmap) {

        memory_global_dirty_log_stop();

        g_free(migration_bitmap);

        migration_bitmap = NULL;

    }

    if (XBZRLE.cache) {

        cache_fini(XBZRLE.cache);

        g_free(XBZRLE.cache);

        g_free(XBZRLE.encoded_buf);

        g_free(XBZRLE.current_buf);

        g_free(XBZRLE.decoded_buf);

        XBZRLE.cache = NULL;

    }

}

static void ram_migration_cancel(void *opaque)

{

    migration_end();

}

static void reset_ram_globals(void)

{

    last_block = NULL;

    last_offset = 0;

    last_version = ram_list.version;

}

#define MAX_WAIT 50 /* ms, half buffered_file limit */

static int ram_save_setup(QEMUFile *f, void *opaque)

{

    RAMBlock *block;

    int64_t ram_pages = last_ram_offset() >> TARGET_PAGE_BITS;

    migration_bitmap = bitmap_new(ram_pages);

    bitmap_set(migration_bitmap, 0, ram_pages);

    migration_dirty_pages = ram_pages;

    qemu_mutex_lock_ramlist();

    bytes_transferred = 0;

    reset_ram_globals();

    if (migrate_use_xbzrle()) {

        XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /

                                  TARGET_PAGE_SIZE,

                                  TARGET_PAGE_SIZE);

        if (!XBZRLE.cache) {

            DPRINTF("Error creating cache\n");

            return -1;

        }

        XBZRLE.encoded_buf = g_malloc0(TARGET_PAGE_SIZE);

        XBZRLE.current_buf = g_malloc(TARGET_PAGE_SIZE);

        acct_clear();

    }

    memory_global_dirty_log_start();

    migration_bitmap_sync();

    qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);

    QTAILQ_FOREACH(block, &ram_list.blocks, next) {

        qemu_put_byte(f, strlen(block->idstr));

        qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));

        qemu_put_be64(f, block->length);

    }

    qemu_mutex_unlock_ramlist();

    qemu_put_be64(f, RAM_SAVE_FLAG_EOS);

    return 0;

}

static int ram_save_iterate(QEMUFile *f, void *opaque)

{

    uint64_t bytes_transferred_last;

    double bwidth = 0;

    int ret;

    int i;

    uint64_t expected_downtime;

    MigrationState *s = migrate_get_current();

    qemu_mutex_lock_ramlist();

    if (ram_list.version != last_version) {

        reset_ram_globals();

    }

    bytes_transferred_last = bytes_transferred;

    bwidth = qemu_get_clock_ns(rt_clock);

    i = 0;

    while ((ret = qemu_file_rate_limit(f)) == 0) {

        int bytes_sent;

        bytes_sent = ram_save_block(f, false);

        /* no more blocks to sent */

        if (bytes_sent < 0) {

            break;

        }

        bytes_transferred += bytes_sent;

        acct_info.iterations++;

        /* we want to check in the 1st loop, just in case it was the 1st time

           and we had to sync the dirty bitmap.

           qemu_get_clock_ns() is a bit expensive, so we only check each some

           iterations

        */

        if ((i & 63) == 0) {

            uint64_t t1 = (qemu_get_clock_ns(rt_clock) - bwidth) / 1000000;

            if (t1 > MAX_WAIT) {

                DPRINTF("big wait: %" PRIu64 " milliseconds, %d iterations\n",

                        t1, i);

                break;

            }

        }

        i++;

    }

    if (ret < 0) {

        return ret;

    }

    bwidth = qemu_get_clock_ns(rt_clock) - bwidth;

    bwidth = (bytes_transferred - bytes_transferred_last) / bwidth;

    /* if we haven't transferred anything this round, force

     * expected_downtime to a very high value, but without

     * crashing */

    if (bwidth == 0) {

        bwidth = 0.000001;

    }

    qemu_mutex_unlock_ramlist();

    qemu_put_be64(f, RAM_SAVE_FLAG_EOS);

    expected_downtime = ram_save_remaining() * TARGET_PAGE_SIZE / bwidth;

    DPRINTF("ram_save_live: expected(%" PRIu64 ") <= max(" PRIu64 ")?\n",

            expected_downtime, migrate_max_downtime());

    if (expected_downtime <= migrate_max_downtime()) {

        migration_bitmap_sync();

        expected_downtime = ram_save_remaining() * TARGET_PAGE_SIZE / bwidth;

        s->expected_downtime = expected_downtime / 1000000; /* ns -> ms */

        return expected_downtime <= migrate_max_downtime();

    }

    return 0;

}

static int ram_save_complete(QEMUFile *f, void *opaque)

{

    migration_bitmap_sync();

    qemu_mutex_lock_ramlist();

    /* try transferring iterative blocks of memory */

    /* flush all remaining blocks regardless of rate limiting */

    while (true) {

        int bytes_sent;

        bytes_sent = ram_save_block(f, true);

        /* no more blocks to sent */

        if (bytes_sent < 0) {

            break;

        }

        bytes_transferred += bytes_sent;

    }

    migration_end();

    qemu_mutex_unlock_ramlist();

    qemu_put_be64(f, RAM_SAVE_FLAG_EOS);

    return 0;

}

static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)

{

    int ret, rc = 0;

    unsigned int xh_len;

    int xh_flags;

    if (!XBZRLE.decoded_buf) {

        XBZRLE.decoded_buf = g_malloc(TARGET_PAGE_SIZE);

    }

    /* extract RLE header */

    xh_flags = qemu_get_byte(f);

    xh_len = qemu_get_be16(f);

    if (xh_flags != ENCODING_FLAG_XBZRLE) {

        fprintf(stderr, "Failed to load XBZRLE page - wrong compression!\n");

        return -1;

    }

    if (xh_len > TARGET_PAGE_SIZE) {

        fprintf(stderr, "Failed to load XBZRLE page - len overflow!\n");

        return -1;

    }

    /* load data and decode */

    qemu_get_buffer(f, XBZRLE.decoded_buf, xh_len);

    /* decode RLE */

    ret = xbzrle_decode_buffer(XBZRLE.decoded_buf, xh_len, host,

                               TARGET_PAGE_SIZE);

    if (ret == -1) {

        fprintf(stderr, "Failed to load XBZRLE page - decode error!\n");

        rc = -1;

    } else  if (ret > TARGET_PAGE_SIZE) {

        fprintf(stderr, "Failed to load XBZRLE page - size %d exceeds %d!\n",

                ret, TARGET_PAGE_SIZE);

        abort();

    }

    return rc;

}

static inline void *host_from_stream_offset(QEMUFile *f,

                                            ram_addr_t offset,

                                            int flags)

{

    static RAMBlock *block = NULL;

    char id[256];

    uint8_t len;

    if (flags & RAM_SAVE_FLAG_CONTINUE) {

        if (!block) {

            fprintf(stderr, "Ack, bad migration stream!\n");

            return NULL;

        }

        return memory_region_get_ram_ptr(block->mr) + offset;

    }

    len = qemu_get_byte(f);

    qemu_get_buffer(f, (uint8_t *)id, len);

    id[len] = 0;

    QTAILQ_FOREACH(block, &ram_list.blocks, next) {

        if (!strncmp(id, block->idstr, sizeof(id)))

            return memory_region_get_ram_ptr(block->mr) + offset;

    }

    fprintf(stderr, "Can't find block %s!\n", id);

    return NULL;

}

static int ram_load(QEMUFile *f, void *opaque, int version_id)

{

    ram_addr_t addr;

    int flags, ret = 0;

    int error;

    static uint64_t seq_iter;

    seq_iter++;

    if (version_id < 4 || version_id > 4) {

        return -EINVAL;

    }

    do {

        addr = qemu_get_be64(f);

        flags = addr & ~TARGET_PAGE_MASK;

        addr &= TARGET_PAGE_MASK;

        if (flags & RAM_SAVE_FLAG_MEM_SIZE) {

            if (version_id == 4) {

                /* Synchronize RAM block list */

                char id[256];

                ram_addr_t length;

                ram_addr_t total_ram_bytes = addr;

                while (total_ram_bytes) {

                    RAMBlock *block;

                    uint8_t len;

                    len = qemu_get_byte(f);

                    qemu_get_buffer(f, (uint8_t *)id, len);

                    id[len] = 0;

                    length = qemu_get_be64(f);

                    QTAILQ_FOREACH(block, &ram_list.blocks, next) {

                        if (!strncmp(id, block->idstr, sizeof(id))) {

                            if (block->length != length) {

                                ret =  -EINVAL;

                                goto done;

                            }

                            break;

                        }

                    }

                    if (!block) {

                        fprintf(stderr, "Unknown ramblock \"%s\", cannot "

                                "accept migration\n", id);

                        ret = -EINVAL;

                        goto done;

                    }

                    total_ram_bytes -= length;

                }

            }

        }

        if (flags & RAM_SAVE_FLAG_COMPRESS) {

            void *host;

            uint8_t ch;

            host = host_from_stream_offset(f, addr, flags);

            if (!host) {

                return -EINVAL;

            }

            ch = qemu_get_byte(f);

            memset(host, ch, TARGET_PAGE_SIZE);

#ifndef _WIN32

            if (ch == 0 &&

                (!kvm_enabled() || kvm_has_sync_mmu()) &&

                getpagesize() <= TARGET_PAGE_SIZE) {

                qemu_madvise(host, TARGET_PAGE_SIZE, QEMU_MADV_DONTNEED);

            }

#endif

        } else if (flags & RAM_SAVE_FLAG_PAGE) {

            void *host;

            host = host_from_stream_offset(f, addr, flags);

            if (!host) {

                return -EINVAL;

            }

            qemu_get_buffer(f, host, TARGET_PAGE_SIZE);

        } else if (flags & RAM_SAVE_FLAG_XBZRLE) {

            if (!migrate_use_xbzrle()) {

                return -EINVAL;

            }

            void *host = host_from_stream_offset(f, addr, flags);

            if (!host) {

                return -EINVAL;

            }

            if (load_xbzrle(f, addr, host) < 0) {

                ret = -EINVAL;

                goto done;

            }

        }

        error = qemu_file_get_error(f);

        if (error) {

            ret = error;

            goto done;

        }

    } while (!(flags & RAM_SAVE_FLAG_EOS));

done:

    DPRINTF("Completed load of VM with exit code %d seq iteration "

            "%" PRIu64 "\n", ret, seq_iter);

    return ret;

}

SaveVMHandlers savevm_ram_handlers = {

    .save_live_setup = ram_save_setup,

    .save_live_iterate = ram_save_iterate,

    .save_live_complete = ram_save_complete,

    .load_state = ram_load,

    .cancel = ram_migration_cancel,

};

#ifdef HAS_AUDIO

struct soundhw {

    const char *name;

    const char *descr;

    int enabled;

    int isa;

    union {

        int (*init_isa) (ISABus *bus);

        int (*init_pci) (PCIBus *bus);

    } init;

};

static struct soundhw soundhw[] = {

#ifdef HAS_AUDIO_CHOICE

#ifdef CONFIG_PCSPK

    {

        "pcspk",

        "PC speaker",

        0,

        1,

        { .init_isa = pcspk_audio_init }

    },

#endif

#ifdef CONFIG_SB16

    {

        "sb16",

        "Creative Sound Blaster 16",