Merge remote-tracking branch 'remotes/juanquintela/tags/migration/20150612' into staging

migration/next for 20150612

# gpg: Signature made Fri Jun 12 05:56:21 2015 BST using RSA key ID 5872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>"
# gpg:                 aka "Juan Quintela <quintela@trasno.org>"

* remotes/juanquintela/tags/migration/20150612: (21 commits)
  Remove unneeded memset
  Rename RDMA structures to make destination clear
  Teach analyze-migration.py about section footers
  Add a protective section footer
  Disable section footers on older machine types
  Merge section header writing
  Move loadvm_handlers into MigrationIncomingState
  Move copy out of qemu_peek_buffer
  Create MigrationIncomingState
  qemu_ram_foreach_block: pass up error value, and down the ramblock name
  Split header writing out of qemu_savevm_state_begin
  Add qemu_get_counted_string to read a string prefixed by a count byte
  migration: Use normal VMStateDescriptions for Subsections
  migration: create savevm_state
  migration: Remove duplicated assignment of SETUP status
  rdma: Fix qemu crash when IPv6 address is used for migration
  arch_init: Clean up the duplicate variable 'len' defining in ram_load()
  migration: reduce include files
  migration: Add myself to the copyright list of both files
  migration: move savevm.c inside migration/
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

49 files changed, 2191 insertions, 2144 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 4ed82154ce..e728d3a1d2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1014,8 +1014,6 @@ M: Amit Shah <amit.shah@redhat.com>
 S: Maintained
 F: include/migration/
 F: migration/
-F: savevm.c
-F: arch_init.c
 F: scripts/vmstate-static-checker.py
 F: tests/vmstate-static-checker-data/
 
diff --git a/Makefile.target b/Makefile.target
index ec5b92cb60..3e7aafd72d 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -132,9 +132,10 @@ obj-y += arch_init.o cpus.o monitor.o gdbstub.o balloon.o ioport.o numa.o
 obj-y += qtest.o bootdevice.o
 obj-y += hw/
 obj-$(CONFIG_KVM) += kvm-all.o
-obj-y += memory.o savevm.o cputlb.o
+obj-y += memory.o cputlb.o
 obj-y += memory_mapping.o
 obj-y += dump.o
+obj-y += migration/ram.o migration/savevm.o
 LIBS := $(libs_softmmu) $(LIBS)
 
 # xen support
diff --git a/arch_init.c b/arch_init.c
index d29447497b..725c638ece 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -22,46 +22,15 @@
  * THE SOFTWARE.
  */
 #include <stdint.h>
-#include <stdarg.h>
-#include <stdlib.h>
-#include <zlib.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/i386/pc.h"
 #include "hw/pci/pci.h"
 #include "hw/audio/audio.h"
-#include "sysemu/kvm.h"
-#include "migration/migration.h"
 #include "hw/i386/smbios.h"
-#include "exec/address-spaces.h"
-#include "hw/audio/pcspk.h"
-#include "migration/page_cache.h"
 #include "qemu/config-file.h"
 #include "qemu/error-report.h"
 #include "qmp-commands.h"
-#include "trace.h"
-#include "exec/cpu-all.h"
-#include "exec/ram_addr.h"
 #include "hw/acpi/acpi.h"
-#include "qemu/host-utils.h"
-#include "qemu/rcu_queue.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;
@@ -111,24 +80,6 @@ int graphic_depth = 32;
 #endif
 
 const uint32_t arch_type = QEMU_ARCH;
-static bool mig_throttle_on;
-static int dirty_rate_high_cnt;
-static void check_guest_throttling(void);
-
-static uint64_t bitmap_sync_count;
-
-/***********************************************************/
-/* 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
-/* 0x80 is reserved in migration.h start with 0x100 next */
-#define RAM_SAVE_FLAG_COMPRESS_PAGE    0x100
 
 static struct defconfig_file {
     const char *filename;
@@ -139,8 +90,6 @@ static struct defconfig_file {
     { NULL }, /* end of list */
 };
 
-static const uint8_t ZERO_TARGET_PAGE[TARGET_PAGE_SIZE];
-
 int qemu_read_default_config_files(bool userconfig)
 {
     int ret;
@@ -159,1517 +108,6 @@ int qemu_read_default_config_files(bool userconfig)
     return 0;
 }
 
-static inline bool is_zero_range(uint8_t *p, uint64_t size)
-{
-    return buffer_find_nonzero_offset(p, size) == size;
-}
-
-/* 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;
-    /* Cache for XBZRLE, Protected by lock. */
-    PageCache *cache;
-    QemuMutex lock;
-} XBZRLE;
-
-/* buffer used for XBZRLE decoding */
-static uint8_t *xbzrle_decoded_buf;
-
-static void XBZRLE_cache_lock(void)
-{
-    if (migrate_use_xbzrle())
-        qemu_mutex_lock(&XBZRLE.lock);
-}
-
-static void XBZRLE_cache_unlock(void)
-{
-    if (migrate_use_xbzrle())
-        qemu_mutex_unlock(&XBZRLE.lock);
-}
-
-/*
- * called from qmp_migrate_set_cache_size in main thread, possibly while
- * a migration is in progress.
- * A running migration maybe using the cache and might finish during this
- * call, hence changes to the cache are protected by XBZRLE.lock().
- */
-int64_t xbzrle_cache_resize(int64_t new_size)
-{
-    PageCache *new_cache;
-    int64_t ret;
-
-    if (new_size < TARGET_PAGE_SIZE) {
-        return -1;
-    }
-
-    XBZRLE_cache_lock();
-
-    if (XBZRLE.cache != NULL) {
-        if (pow2floor(new_size) == migrate_xbzrle_cache_size()) {
-            goto out_new_size;
-        }
-        new_cache = cache_init(new_size / TARGET_PAGE_SIZE,
-                                        TARGET_PAGE_SIZE);
-        if (!new_cache) {
-            error_report("Error creating cache");
-            ret = -1;
-            goto out;
-        }
-
-        cache_fini(XBZRLE.cache);
-        XBZRLE.cache = new_cache;
-    }
-
-out_new_size:
-    ret = pow2floor(new_size);
-out:
-    XBZRLE_cache_unlock();
-    return ret;
-}
-
-/* accounting for migration statistics */
-typedef struct AccountingInfo {
-    uint64_t dup_pages;
-    uint64_t skipped_pages;
-    uint64_t norm_pages;
-    uint64_t iterations;
-    uint64_t xbzrle_bytes;
-    uint64_t xbzrle_pages;
-    uint64_t xbzrle_cache_miss;
-    double xbzrle_cache_miss_rate;
-    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 skipped_mig_bytes_transferred(void)
-{
-    return acct_info.skipped_pages * TARGET_PAGE_SIZE;
-}
-
-uint64_t skipped_mig_pages_transferred(void)
-{
-    return acct_info.skipped_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;
-}
-
-double xbzrle_mig_cache_miss_rate(void)
-{
-    return acct_info.xbzrle_cache_miss_rate;
-}
-
-uint64_t xbzrle_mig_pages_overflow(void)
-{
-    return acct_info.xbzrle_overflows;
-}
-
-/* This is the last block that we have visited serching for dirty pages
- */
-static RAMBlock *last_seen_block;
-/* This is the last block from where we have sent data */
-static RAMBlock *last_sent_block;
-static ram_addr_t last_offset;
-static unsigned long *migration_bitmap;
-static uint64_t migration_dirty_pages;
-static uint32_t last_version;
-static bool ram_bulk_stage;
-
-struct CompressParam {
-    bool start;
-    bool done;
-    QEMUFile *file;
-    QemuMutex mutex;
-    QemuCond cond;
-    RAMBlock *block;
-    ram_addr_t offset;
-};
-typedef struct CompressParam CompressParam;
-
-struct DecompressParam {
-    bool start;
-    QemuMutex mutex;
-    QemuCond cond;
-    void *des;
-    uint8 *compbuf;
-    int len;
-};
-typedef struct DecompressParam DecompressParam;
-
-static CompressParam *comp_param;
-static QemuThread *compress_threads;
-/* comp_done_cond is used to wake up the migration thread when
- * one of the compression threads has finished the compression.
- * comp_done_lock is used to co-work with comp_done_cond.
- */
-static QemuMutex *comp_done_lock;
-static QemuCond *comp_done_cond;
-/* The empty QEMUFileOps will be used by file in CompressParam */
-static const QEMUFileOps empty_ops = { };
-
-static bool compression_switch;
-static bool quit_comp_thread;
-static bool quit_decomp_thread;
-static DecompressParam *decomp_param;
-static QemuThread *decompress_threads;
-static uint8_t *compressed_data_buf;
-
-static int do_compress_ram_page(CompressParam *param);
-
-static void *do_data_compress(void *opaque)
-{
-    CompressParam *param = opaque;
-
-    while (!quit_comp_thread) {
-        qemu_mutex_lock(&param->mutex);
-        /* Re-check the quit_comp_thread in case of
-         * terminate_compression_threads is called just before
-         * qemu_mutex_lock(&param->mutex) and after
-         * while(!quit_comp_thread), re-check it here can make
-         * sure the compression thread terminate as expected.
-         */
-        while (!param->start && !quit_comp_thread) {
-            qemu_cond_wait(&param->cond, &param->mutex);
-        }
-        if (!quit_comp_thread) {
-            do_compress_ram_page(param);
-        }
-        param->start = false;
-        qemu_mutex_unlock(&param->mutex);
-
-        qemu_mutex_lock(comp_done_lock);
-        param->done = true;
-        qemu_cond_signal(comp_done_cond);
-        qemu_mutex_unlock(comp_done_lock);
-    }
-
-    return NULL;
-}
-
-static inline void terminate_compression_threads(void)
-{
-    int idx, thread_count;
-
-    thread_count = migrate_compress_threads();
-    quit_comp_thread = true;
-    for (idx = 0; idx < thread_count; idx++) {
-        qemu_mutex_lock(&comp_param[idx].mutex);
-        qemu_cond_signal(&comp_param[idx].cond);
-        qemu_mutex_unlock(&comp_param[idx].mutex);
-    }
-}
-
-void migrate_compress_threads_join(void)
-{
-    int i, thread_count;
-
-    if (!migrate_use_compression()) {
-        return;
-    }
-    terminate_compression_threads();
-    thread_count = migrate_compress_threads();
-    for (i = 0; i < thread_count; i++) {
-        qemu_thread_join(compress_threads + i);
-        qemu_fclose(comp_param[i].file);
-        qemu_mutex_destroy(&comp_param[i].mutex);
-        qemu_cond_destroy(&comp_param[i].cond);
-    }
-    qemu_mutex_destroy(comp_done_lock);
-    qemu_cond_destroy(comp_done_cond);
-    g_free(compress_threads);
-    g_free(comp_param);
-    g_free(comp_done_cond);
-    g_free(comp_done_lock);
-    compress_threads = NULL;
-    comp_param = NULL;
-    comp_done_cond = NULL;
-    comp_done_lock = NULL;
-}
-
-void migrate_compress_threads_create(void)
-{
-    int i, thread_count;
-
-    if (!migrate_use_compression()) {
-        return;
-    }
-    quit_comp_thread = false;
-    compression_switch = true;
-    thread_count = migrate_compress_threads();
-    compress_threads = g_new0(QemuThread, thread_count);
-    comp_param = g_new0(CompressParam, thread_count);
-    comp_done_cond = g_new0(QemuCond, 1);
-    comp_done_lock = g_new0(QemuMutex, 1);
-    qemu_cond_init(comp_done_cond);
-    qemu_mutex_init(comp_done_lock);
-    for (i = 0; i < thread_count; i++) {
-        /* com_param[i].file is just used as a dummy buffer to save data, set
-         * it's ops to empty.
-         */
-        comp_param[i].file = qemu_fopen_ops(NULL, &empty_ops);
-        comp_param[i].done = true;
-        qemu_mutex_init(&comp_param[i].mutex);
-        qemu_cond_init(&comp_param[i].cond);
-        qemu_thread_create(compress_threads + i, "compress",
-                           do_data_compress, comp_param + i,
-                           QEMU_THREAD_JOINABLE);
-    }
-}
-
-/**
- * save_page_header: Write page header to wire
- *
- * If this is the 1st block, it also writes the block identification
- *
- * Returns: Number of bytes written
- *
- * @f: QEMUFile where to send the data
- * @block: block that contains the page we want to send
- * @offset: offset inside the block for the page
- *          in the lower bits, it contains flags
- */
-static size_t save_page_header(QEMUFile *f, RAMBlock *block, ram_addr_t offset)
-{
-    size_t size;
-
-    qemu_put_be64(f, offset);
-    size = 8;
-
-    if (!(offset & RAM_SAVE_FLAG_CONTINUE)) {
-        qemu_put_byte(f, strlen(block->idstr));
-        qemu_put_buffer(f, (uint8_t *)block->idstr,
-                        strlen(block->idstr));
-        size += 1 + strlen(block->idstr);
-    }
-    return size;
-}
-
-/* Update the xbzrle cache to reflect a page that's been sent as all 0.
- * The important thing is that a stale (not-yet-0'd) page be replaced
- * by the new data.
- * As a bonus, if the page wasn't in the cache it gets added so that
- * when a small write is made into the 0'd page it gets XBZRLE sent
- */
-static void xbzrle_cache_zero_page(ram_addr_t current_addr)
-{
-    if (ram_bulk_stage || !migrate_use_xbzrle()) {
-        return;
-    }
-
-    /* We don't care if this fails to allocate a new cache page
-     * as long as it updated an old one */
-    cache_insert(XBZRLE.cache, current_addr, ZERO_TARGET_PAGE,
-                 bitmap_sync_count);
-}
-
-#define ENCODING_FLAG_XBZRLE 0x1
-
-/**
- * save_xbzrle_page: compress and send current page
- *
- * Returns: 1 means that we wrote the page
- *          0 means that page is identical to the one already sent
- *          -1 means that xbzrle would be longer than normal
- *
- * @f: QEMUFile where to send the data
- * @current_data:
- * @current_addr:
- * @block: block that contains the page we want to send
- * @offset: offset inside the block for the page
- * @last_stage: if we are at the completion stage
- * @bytes_transferred: increase it with the number of transferred bytes
- */
-static int save_xbzrle_page(QEMUFile *f, uint8_t **current_data,
-                            ram_addr_t current_addr, RAMBlock *block,
-                            ram_addr_t offset, bool last_stage,
-                            uint64_t *bytes_transferred)
-{
-    int encoded_len = 0, bytes_xbzrle;
-    uint8_t *prev_cached_page;
-
-    if (!cache_is_cached(XBZRLE.cache, current_addr, bitmap_sync_count)) {
-        acct_info.xbzrle_cache_miss++;
-        if (!last_stage) {
-            if (cache_insert(XBZRLE.cache, current_addr, *current_data,
-                             bitmap_sync_count) == -1) {
-                return -1;
-            } else {
-                /* update *current_data when the page has been
-                   inserted into cache */
-                *current_data = get_cached_data(XBZRLE.cache, current_addr);
-            }
-        }
-        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 */
-        if (!last_stage) {
-            memcpy(prev_cached_page, *current_data, TARGET_PAGE_SIZE);
-            *current_data = prev_cached_page;
-        }
-        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 */
-    bytes_xbzrle = save_page_header(f, block, offset | 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_xbzrle += encoded_len + 1 + 2;
-    acct_info.xbzrle_pages++;
-    acct_info.xbzrle_bytes += bytes_xbzrle;
-    *bytes_transferred += bytes_xbzrle;
-
-    return 1;
-}
-
-static inline
-ram_addr_t migration_bitmap_find_and_reset_dirty(MemoryRegion *mr,
-                                                 ram_addr_t start)
-{
-    unsigned long base = mr->ram_addr >> TARGET_PAGE_BITS;
-    unsigned long nr = base + (start >> TARGET_PAGE_BITS);
-    uint64_t mr_size = TARGET_PAGE_ALIGN(memory_region_size(mr));
-    unsigned long size = base + (mr_size >> TARGET_PAGE_BITS);
-
-    unsigned long next;
-
-    if (ram_bulk_stage && nr > base) {
-        next = nr + 1;
-    } else {
-        next = find_next_bit(migration_bitmap, size, nr);
-    }
-
-    if (next < size) {
-        clear_bit(next, migration_bitmap);
-        migration_dirty_pages--;
-    }
-    return (next - base) << TARGET_PAGE_BITS;
-}
-
-static void migration_bitmap_sync_range(ram_addr_t start, ram_addr_t length)
-{
-    migration_dirty_pages +=
-        cpu_physical_memory_sync_dirty_bitmap(migration_bitmap, start, length);
-}
-
-
-/* Fix me: there are too many global variables used in migration process. */
-static int64_t start_time;
-static int64_t bytes_xfer_prev;
-static int64_t num_dirty_pages_period;
-static uint64_t xbzrle_cache_miss_prev;
-static uint64_t iterations_prev;
-
-static void migration_bitmap_sync_init(void)
-{
-    start_time = 0;
-    bytes_xfer_prev = 0;
-    num_dirty_pages_period = 0;
-    xbzrle_cache_miss_prev = 0;
-    iterations_prev = 0;
-}
-
-/* Called with iothread lock held, to protect ram_list.dirty_memory[] */
-static void migration_bitmap_sync(void)
-{
-    RAMBlock *block;
-    uint64_t num_dirty_pages_init = migration_dirty_pages;
-    MigrationState *s = migrate_get_current();
-    int64_t end_time;
-    int64_t bytes_xfer_now;
-
-    bitmap_sync_count++;
-
-    if (!bytes_xfer_prev) {
-        bytes_xfer_prev = ram_bytes_transferred();
-    }
-
-    if (!start_time) {
-        start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
-    }
-
-    trace_migration_bitmap_sync_start();
-    address_space_sync_dirty_bitmap(&address_space_memory);
-
-    rcu_read_lock();
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
-        migration_bitmap_sync_range(block->mr->ram_addr, block->used_length);
-    }
-    rcu_read_unlock();
-
-    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_clock_get_ms(QEMU_CLOCK_REALTIME);
-
-    /* more than 1 second = 1000 millisecons */
-    if (end_time > start_time + 1000) {
-        if (migrate_auto_converge()) {
-            /* The following detection logic can be refined later. For now:
-               Check to see if the dirtied bytes is 50% more than the approx.
-               amount of bytes that just got transferred since the last time we
-               were in this routine. If that happens >N times (for now N==4)
-               we turn on the throttle down logic */
-            bytes_xfer_now = ram_bytes_transferred();
-            if (s->dirty_pages_rate &&
-               (num_dirty_pages_period * TARGET_PAGE_SIZE >
-                   (bytes_xfer_now - bytes_xfer_prev)/2) &&
-               (dirty_rate_high_cnt++ > 4)) {
-                    trace_migration_throttle();
-                    mig_throttle_on = true;
-                    dirty_rate_high_cnt = 0;
-             }
-             bytes_xfer_prev = bytes_xfer_now;
-        } else {
-             mig_throttle_on = false;
-        }
-        if (migrate_use_xbzrle()) {
-            if (iterations_prev != acct_info.iterations) {
-                acct_info.xbzrle_cache_miss_rate =
-                   (double)(acct_info.xbzrle_cache_miss -
-                            xbzrle_cache_miss_prev) /
-                   (acct_info.iterations - iterations_prev);
-            }
-            iterations_prev = acct_info.iterations;
-            xbzrle_cache_miss_prev = acct_info.xbzrle_cache_miss;
-        }
-        s->dirty_pages_rate = num_dirty_pages_period * 1000
-            / (end_time - start_time);
-        s->dirty_bytes_rate = s->dirty_pages_rate * TARGET_PAGE_SIZE;
-        start_time = end_time;
-        num_dirty_pages_period = 0;
-    }
-    s->dirty_sync_count = bitmap_sync_count;
-}
-
-/**
- * save_zero_page: Send the zero page to the stream
- *
- * Returns: Number of pages written.
- *
- * @f: QEMUFile where to send the data
- * @block: block that contains the page we want to send
- * @offset: offset inside the block for the page
- * @p: pointer to the page
- * @bytes_transferred: increase it with the number of transferred bytes
- */
-static int save_zero_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
-                          uint8_t *p, uint64_t *bytes_transferred)
-{
-    int pages = -1;
-
-    if (is_zero_range(p, TARGET_PAGE_SIZE)) {
-        acct_info.dup_pages++;
-        *bytes_transferred += save_page_header(f, block,
-                                               offset | RAM_SAVE_FLAG_COMPRESS);
-        qemu_put_byte(f, 0);
-        *bytes_transferred += 1;
-        pages = 1;
-    }
-
-    return pages;
-}
-
-/**
- * ram_save_page: Send the given page to the stream
- *
- * Returns: Number of pages written.
- *
- * @f: QEMUFile where to send the data
- * @block: block that contains the page we want to send
- * @offset: offset inside the block for the page
- * @last_stage: if we are at the completion stage
- * @bytes_transferred: increase it with the number of transferred bytes
- */
-static int ram_save_page(QEMUFile *f, RAMBlock* block, ram_addr_t offset,
-                         bool last_stage, uint64_t *bytes_transferred)
-{
-    int pages = -1;
-    uint64_t bytes_xmit;
-    ram_addr_t current_addr;
-    MemoryRegion *mr = block->mr;
-    uint8_t *p;
-    int ret;
-    bool send_async = true;
-
-    p = memory_region_get_ram_ptr(mr) + offset;
-
-    /* In doubt sent page as normal */
-    bytes_xmit = 0;
-    ret = ram_control_save_page(f, block->offset,
-                           offset, TARGET_PAGE_SIZE, &bytes_xmit);
-    if (bytes_xmit) {
-        *bytes_transferred += bytes_xmit;
-        pages = 1;
-    }
-
-    XBZRLE_cache_lock();
-
-    current_addr = block->offset + offset;
-
-    if (block == last_sent_block) {
-        offset |= RAM_SAVE_FLAG_CONTINUE;
-    }
-    if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
-        if (ret != RAM_SAVE_CONTROL_DELAYED) {
-            if (bytes_xmit > 0) {
-                acct_info.norm_pages++;
-            } else if (bytes_xmit == 0) {
-                acct_info.dup_pages++;
-            }
-        }
-    } else {
-        pages = save_zero_page(f, block, offset, p, bytes_transferred);
-        if (pages > 0) {
-            /* Must let xbzrle know, otherwise a previous (now 0'd) cached
-             * page would be stale
-             */
-            xbzrle_cache_zero_page(current_addr);
-        } else if (!ram_bulk_stage && migrate_use_xbzrle()) {
-            pages = save_xbzrle_page(f, &p, current_addr, block,
-                                     offset, last_stage, bytes_transferred);
-            if (!last_stage) {
-                /* Can't send this cached data async, since the cache page
-                 * might get updated before it gets to the wire
-                 */
-                send_async = false;
-            }
-        }
-    }
-
-    /* XBZRLE overflow or normal page */
-    if (pages == -1) {
-        *bytes_transferred += save_page_header(f, block,
-                                               offset | RAM_SAVE_FLAG_PAGE);
-        if (send_async) {
-            qemu_put_buffer_async(f, p, TARGET_PAGE_SIZE);
-        } else {
-            qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
-        }
-        *bytes_transferred += TARGET_PAGE_SIZE;
-        pages = 1;
-        acct_info.norm_pages++;
-    }
-
-    XBZRLE_cache_unlock();
-
-    return pages;
-}
-
-static int do_compress_ram_page(CompressParam *param)
-{
-    int bytes_sent, blen;
-    uint8_t *p;
-    RAMBlock *block = param->block;
-    ram_addr_t offset = param->offset;
-
-    p = memory_region_get_ram_ptr(block->mr) + (offset & TARGET_PAGE_MASK);
-
-    bytes_sent = save_page_header(param->file, block, offset |
-                                  RAM_SAVE_FLAG_COMPRESS_PAGE);
-    blen = qemu_put_compression_data(param->file, p, TARGET_PAGE_SIZE,
-                                     migrate_compress_level());
-    bytes_sent += blen;
-
-    return bytes_sent;
-}
-
-static inline void start_compression(CompressParam *param)
-{
-    param->done = false;
-    qemu_mutex_lock(&param->mutex);
-    param->start = true;
-    qemu_cond_signal(&param->cond);
-    qemu_mutex_unlock(&param->mutex);
-}
-
-static inline void start_decompression(DecompressParam *param)
-{
-    qemu_mutex_lock(&param->mutex);
-    param->start = true;
-    qemu_cond_signal(&param->cond);
-    qemu_mutex_unlock(&param->mutex);
-}
-
-static uint64_t bytes_transferred;
-
-static void flush_compressed_data(QEMUFile *f)
-{
-    int idx, len, thread_count;
-
-    if (!migrate_use_compression()) {
-        return;
-    }
-    thread_count = migrate_compress_threads();
-    for (idx = 0; idx < thread_count; idx++) {
-        if (!comp_param[idx].done) {
-            qemu_mutex_lock(comp_done_lock);
-            while (!comp_param[idx].done && !quit_comp_thread) {
-                qemu_cond_wait(comp_done_cond, comp_done_lock);
-            }
-            qemu_mutex_unlock(comp_done_lock);
-        }
-        if (!quit_comp_thread) {
-            len = qemu_put_qemu_file(f, comp_param[idx].file);
-            bytes_transferred += len;
-        }
-    }
-}
-
-static inline void set_compress_params(CompressParam *param, RAMBlock *block,
-                                       ram_addr_t offset)
-{
-    param->block = block;
-    param->offset = offset;
-}
-
-static int compress_page_with_multi_thread(QEMUFile *f, RAMBlock *block,
-                                           ram_addr_t offset,
-                                           uint64_t *bytes_transferred)
-{
-    int idx, thread_count, bytes_xmit = -1, pages = -1;
-
-    thread_count = migrate_compress_threads();
-    qemu_mutex_lock(comp_done_lock);
-    while (true) {
-        for (idx = 0; idx < thread_count; idx++) {
-            if (comp_param[idx].done) {
-                bytes_xmit = qemu_put_qemu_file(f, comp_param[idx].file);
-                set_compress_params(&comp_param[idx], block, offset);
-                start_compression(&comp_param[idx]);
-                pages = 1;
-                acct_info.norm_pages++;
-                *bytes_transferred += bytes_xmit;
-                break;
-            }
-        }
-        if (pages > 0) {
-            break;
-        } else {
-            qemu_cond_wait(comp_done_cond, comp_done_lock);
-        }
-    }
-    qemu_mutex_unlock(comp_done_lock);
-
-    return pages;
-}
-
-/**
- * ram_save_compressed_page: compress the given page and send it to the stream
- *
- * Returns: Number of pages written.
- *
- * @f: QEMUFile where to send the data
- * @block: block that contains the page we want to send
- * @offset: offset inside the block for the page
- * @last_stage: if we are at the completion stage
- * @bytes_transferred: increase it with the number of transferred bytes
- */
-static int ram_save_compressed_page(QEMUFile *f, RAMBlock *block,
-                                    ram_addr_t offset, bool last_stage,
-                                    uint64_t *bytes_transferred)
-{
-    int pages = -1;
-    uint64_t bytes_xmit;
-    MemoryRegion *mr = block->mr;
-    uint8_t *p;
-    int ret;
-
-    p = memory_region_get_ram_ptr(mr) + offset;
-
-    bytes_xmit = 0;
-    ret = ram_control_save_page(f, block->offset,
-                                offset, TARGET_PAGE_SIZE, &bytes_xmit);
-    if (bytes_xmit) {
-        *bytes_transferred += bytes_xmit;
-        pages = 1;
-    }
-    if (block == last_sent_block) {
-        offset |= RAM_SAVE_FLAG_CONTINUE;
-    }
-    if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
-        if (ret != RAM_SAVE_CONTROL_DELAYED) {
-            if (bytes_xmit > 0) {
-                acct_info.norm_pages++;
-            } else if (bytes_xmit == 0) {
-                acct_info.dup_pages++;
-            }
-        }
-    } else {
-        /* When starting the process of a new block, the first page of
-         * the block should be sent out before other pages in the same
-         * block, and all the pages in last block should have been sent
-         * out, keeping this order is important, because the 'cont' flag
-         * is used to avoid resending the block name.
-         */
-        if (block != last_sent_block) {
-            flush_compressed_data(f);
-            pages = save_zero_page(f, block, offset, p, bytes_transferred);
-            if (pages == -1) {
-                set_compress_params(&comp_param[0], block, offset);
-                /* Use the qemu thread to compress the data to make sure the
-                 * first page is sent out before other pages
-                 */
-                bytes_xmit = do_compress_ram_page(&comp_param[0]);
-                acct_info.norm_pages++;
-                qemu_put_qemu_file(f, comp_param[0].file);
-                *bytes_transferred += bytes_xmit;
-                pages = 1;
-            }
-        } else {
-            pages = save_zero_page(f, block, offset, p, bytes_transferred);
-            if (pages == -1) {
-                pages = compress_page_with_multi_thread(f, block, offset,
-                                                        bytes_transferred);
-            }
-        }
-    }
-
-    return pages;
-}
-
-/**
- * ram_find_and_save_block: Finds a dirty page and sends it to f
- *
- * Called within an RCU critical section.
- *
- * Returns:  The number of pages written
- *           0 means no dirty pages
- *
- * @f: QEMUFile where to send the data
- * @last_stage: if we are at the completion stage
- * @bytes_transferred: increase it with the number of transferred bytes
- */
-
-static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
-                                   uint64_t *bytes_transferred)
-{
-    RAMBlock *block = last_seen_block;
-    ram_addr_t offset = last_offset;
-    bool complete_round = false;
-    int pages = 0;
-    MemoryRegion *mr;
-
-    if (!block)
-        block = QLIST_FIRST_RCU(&ram_list.blocks);
-
-    while (true) {
-        mr = block->mr;
-        offset = migration_bitmap_find_and_reset_dirty(mr, offset);
-        if (complete_round && block == last_seen_block &&
-            offset >= last_offset) {
-            break;
-        }
-        if (offset >= block->used_length) {
-            offset = 0;
-            block = QLIST_NEXT_RCU(block, next);
-            if (!block) {
-                block = QLIST_FIRST_RCU(&ram_list.blocks);
-                complete_round = true;
-                ram_bulk_stage = false;
-                if (migrate_use_xbzrle()) {
-                    /* If xbzrle is on, stop using the data compression at this
-                     * point. In theory, xbzrle can do better than compression.
-                     */
-                    flush_compressed_data(f);
-                    compression_switch = false;
-                }
-            }
-        } else {
-            if (compression_switch && migrate_use_compression()) {
-                pages = ram_save_compressed_page(f, block, offset, last_stage,
-                                                 bytes_transferred);
-            } else {
-                pages = ram_save_page(f, block, offset, last_stage,
-                                      bytes_transferred);
-            }
-
-            /* if page is unmodified, continue to the next */
-            if (pages > 0) {
-                last_sent_block = block;
-                break;
-            }
-        }
-    }
-
-    last_seen_block = block;
-    last_offset = offset;
-
-    return pages;
-}
-
-void acct_update_position(QEMUFile *f, size_t size, bool zero)
-{
-    uint64_t pages = size / TARGET_PAGE_SIZE;
-    if (zero) {
-        acct_info.dup_pages += pages;
-    } else {
-        acct_info.norm_pages += pages;
-        bytes_transferred += size;
-        qemu_update_position(f, size);
-    }
-}
-
-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;
-
-    rcu_read_lock();
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next)
-        total += block->used_length;
-    rcu_read_unlock();
-    return total;
-}
-
-void free_xbzrle_decoded_buf(void)
-{
-    g_free(xbzrle_decoded_buf);
-    xbzrle_decoded_buf = NULL;
-}
-
-static void migration_end(void)
-{
-    if (migration_bitmap) {
-        memory_global_dirty_log_stop();
-        g_free(migration_bitmap);
-        migration_bitmap = NULL;
-    }
-
-    XBZRLE_cache_lock();
-    if (XBZRLE.cache) {
-        cache_fini(XBZRLE.cache);
-        g_free(XBZRLE.encoded_buf);
-        g_free(XBZRLE.current_buf);
-        XBZRLE.cache = NULL;
-        XBZRLE.encoded_buf = NULL;
-        XBZRLE.current_buf = NULL;
-    }
-    XBZRLE_cache_unlock();
-}
-
-static void ram_migration_cancel(void *opaque)
-{
-    migration_end();
-}
-
-static void reset_ram_globals(void)
-{
-    last_seen_block = NULL;
-    last_sent_block = NULL;
-    last_offset = 0;
-    last_version = ram_list.version;
-    ram_bulk_stage = true;
-}
-
-#define MAX_WAIT 50 /* ms, half buffered_file limit */
-
-
-/* Each of ram_save_setup, ram_save_iterate and ram_save_complete has
- * long-running RCU critical section.  When rcu-reclaims in the code
- * start to become numerous it will be necessary to reduce the
- * granularity of these critical sections.
- */
-
-static int ram_save_setup(QEMUFile *f, void *opaque)
-{
-    RAMBlock *block;
-    int64_t ram_bitmap_pages; /* Size of bitmap in pages, including gaps */
-
-    mig_throttle_on = false;
-    dirty_rate_high_cnt = 0;
-    bitmap_sync_count = 0;
-    migration_bitmap_sync_init();
-
-    if (migrate_use_xbzrle()) {
-        XBZRLE_cache_lock();
-        XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
-                                  TARGET_PAGE_SIZE,
-                                  TARGET_PAGE_SIZE);
-        if (!XBZRLE.cache) {
-            XBZRLE_cache_unlock();
-            error_report("Error creating cache");
-            return -1;
-        }
-        XBZRLE_cache_unlock();
-
-        /* We prefer not to abort if there is no memory */
-        XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE);
-        if (!XBZRLE.encoded_buf) {
-            error_report("Error allocating encoded_buf");
-            return -1;
-        }
-
-        XBZRLE.current_buf = g_try_malloc(TARGET_PAGE_SIZE);
-        if (!XBZRLE.current_buf) {
-            error_report("Error allocating current_buf");
-            g_free(XBZRLE.encoded_buf);
-            XBZRLE.encoded_buf = NULL;
-            return -1;
-        }
-
-        acct_clear();
-    }
-
-    /* iothread lock needed for ram_list.dirty_memory[] */
-    qemu_mutex_lock_iothread();
-    qemu_mutex_lock_ramlist();
-    rcu_read_lock();
-    bytes_transferred = 0;
-    reset_ram_globals();
-
-    ram_bitmap_pages = last_ram_offset() >> TARGET_PAGE_BITS;
-    migration_bitmap = bitmap_new(ram_bitmap_pages);
-    bitmap_set(migration_bitmap, 0, ram_bitmap_pages);
-
-    /*
-     * Count the total number of pages used by ram blocks not including any
-     * gaps due to alignment or unplugs.
-     */
-    migration_dirty_pages = ram_bytes_total() >> TARGET_PAGE_BITS;
-
-    memory_global_dirty_log_start();
-    migration_bitmap_sync();
-    qemu_mutex_unlock_ramlist();
-    qemu_mutex_unlock_iothread();
-
-    qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
-
-    QLIST_FOREACH_RCU(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->used_length);
-    }
-
-    rcu_read_unlock();
-
-    ram_control_before_iterate(f, RAM_CONTROL_SETUP);
-    ram_control_after_iterate(f, RAM_CONTROL_SETUP);
-
-    qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
-
-    return 0;
-}
-
-static int ram_save_iterate(QEMUFile *f, void *opaque)
-{
-    int ret;
-    int i;
-    int64_t t0;
-    int pages_sent = 0;
-
-    rcu_read_lock();
-    if (ram_list.version != last_version) {
-        reset_ram_globals();
-    }
-
-    /* Read version before ram_list.blocks */
-    smp_rmb();
-
-    ram_control_before_iterate(f, RAM_CONTROL_ROUND);
-
-    t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
-    i = 0;
-    while ((ret = qemu_file_rate_limit(f)) == 0) {
-        int pages;
-
-        pages = ram_find_and_save_block(f, false, &bytes_transferred);
-        /* no more pages to sent */
-        if (pages == 0) {
-            break;
-        }
-        pages_sent += pages;
-        acct_info.iterations++;
-        check_guest_throttling();
-        /* 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_clock_get_ns(QEMU_CLOCK_REALTIME) - t0) / 1000000;
-            if (t1 > MAX_WAIT) {
-                DPRINTF("big wait: %" PRIu64 " milliseconds, %d iterations\n",
-                        t1, i);
-                break;
-            }
-        }
-        i++;
-    }
-    flush_compressed_data(f);
-    rcu_read_unlock();
-
-    /*
-     * Must occur before EOS (or any QEMUFile operation)
-     * because of RDMA protocol.
-     */
-    ram_control_after_iterate(f, RAM_CONTROL_ROUND);
-
-    qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
-    bytes_transferred += 8;
-
-    ret = qemu_file_get_error(f);
-    if (ret < 0) {
-        return ret;
-    }
-
-    return pages_sent;
-}
-
-/* Called with iothread lock */
-static int ram_save_complete(QEMUFile *f, void *opaque)
-{
-    rcu_read_lock();
-
-    migration_bitmap_sync();
-
-    ram_control_before_iterate(f, RAM_CONTROL_FINISH);
-
-    /* try transferring iterative blocks of memory */
-
-    /* flush all remaining blocks regardless of rate limiting */
-    while (true) {
-        int pages;
-
-        pages = ram_find_and_save_block(f, true, &bytes_transferred);
-        /* no more blocks to sent */
-        if (pages == 0) {
-            break;
-        }
-    }
-
-    flush_compressed_data(f);
-    ram_control_after_iterate(f, RAM_CONTROL_FINISH);
-    migration_end();
-
-    rcu_read_unlock();
-    qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
-
-    return 0;
-}
-
-static uint64_t ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
-{
-    uint64_t remaining_size;
-
-    remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
-
-    if (remaining_size < max_size) {
-        qemu_mutex_lock_iothread();
-        rcu_read_lock();
-        migration_bitmap_sync();
-        rcu_read_unlock();
-        qemu_mutex_unlock_iothread();
-        remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
-    }
-    return remaining_size;
-}
-
-static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
-{
-    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) {
-        error_report("Failed to load XBZRLE page - wrong compression!");
-        return -1;
-    }
-
-    if (xh_len > TARGET_PAGE_SIZE) {
-        error_report("Failed to load XBZRLE page - len overflow!");
-        return -1;
-    }
-    /* load data and decode */
-    qemu_get_buffer(f, xbzrle_decoded_buf, xh_len);
-
-    /* decode RLE */
-    if (xbzrle_decode_buffer(xbzrle_decoded_buf, xh_len, host,
-                             TARGET_PAGE_SIZE) == -1) {
-        error_report("Failed to load XBZRLE page - decode error!");
-        return -1;
-    }
-
-    return 0;
-}
-
-/* Must be called from within a rcu critical section.
- * Returns a pointer from within the RCU-protected ram_list.
- */
-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 || block->max_length <= offset) {
-            error_report("Ack, bad migration stream!");
-            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;
-
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
-        if (!strncmp(id, block->idstr, sizeof(id)) &&
-            block->max_length > offset) {
-            return memory_region_get_ram_ptr(block->mr) + offset;
-        }
-    }
-
-    error_report("Can't find block %s!", id);
-    return NULL;
-}
-
-/*
- * If a page (or a whole RDMA chunk) has been
- * determined to be zero, then zap it.
- */
-void ram_handle_compressed(void *host, uint8_t ch, uint64_t size)
-{
-    if (ch != 0 || !is_zero_range(host, size)) {
-        memset(host, ch, size);
-    }
-}
-
-static void *do_data_decompress(void *opaque)
-{
-    DecompressParam *param = opaque;
-    unsigned long pagesize;
-
-    while (!quit_decomp_thread) {
-        qemu_mutex_lock(&param->mutex);
-        while (!param->start && !quit_decomp_thread) {
-            qemu_cond_wait(&param->cond, &param->mutex);
-            pagesize = TARGET_PAGE_SIZE;
-            if (!quit_decomp_thread) {
-                /* uncompress() will return failed in some case, especially
-                 * when the page is dirted when doing the compression, it's
-                 * not a problem because the dirty page will be retransferred
-                 * and uncompress() won't break the data in other pages.
-                 */
-                uncompress((Bytef *)param->des, &pagesize,
-                           (const Bytef *)param->compbuf, param->len);
-            }
-            param->start = false;
-        }
-        qemu_mutex_unlock(&param->mutex);
-    }
-
-    return NULL;
-}
-
-void migrate_decompress_threads_create(void)
-{
-    int i, thread_count;
-
-    thread_count = migrate_decompress_threads();
-    decompress_threads = g_new0(QemuThread, thread_count);
-    decomp_param = g_new0(DecompressParam, thread_count);
-    compressed_data_buf = g_malloc0(compressBound(TARGET_PAGE_SIZE));
-    quit_decomp_thread = false;
-    for (i = 0; i < thread_count; i++) {
-        qemu_mutex_init(&decomp_param[i].mutex);
-        qemu_cond_init(&decomp_param[i].cond);
-        decomp_param[i].compbuf = g_malloc0(compressBound(TARGET_PAGE_SIZE));
-        qemu_thread_create(decompress_threads + i, "decompress",
-                           do_data_decompress, decomp_param + i,
-                           QEMU_THREAD_JOINABLE);
-    }
-}
-
-void migrate_decompress_threads_join(void)
-{
-    int i, thread_count;
-
-    quit_decomp_thread = true;
-    thread_count = migrate_decompress_threads();
-    for (i = 0; i < thread_count; i++) {
-        qemu_mutex_lock(&decomp_param[i].mutex);
-        qemu_cond_signal(&decomp_param[i].cond);
-        qemu_mutex_unlock(&decomp_param[i].mutex);
-    }
-    for (i = 0; i < thread_count; i++) {
-        qemu_thread_join(decompress_threads + i);
-        qemu_mutex_destroy(&decomp_param[i].mutex);
-        qemu_cond_destroy(&decomp_param[i].cond);
-        g_free(decomp_param[i].compbuf);
-    }
-    g_free(decompress_threads);
-    g_free(decomp_param);
-    g_free(compressed_data_buf);
-    decompress_threads = NULL;
-    decomp_param = NULL;
-    compressed_data_buf = NULL;
-}
-
-static void decompress_data_with_multi_threads(uint8_t *compbuf,
-                                               void *host, int len)
-{
-    int idx, thread_count;
-
-    thread_count = migrate_decompress_threads();
-    while (true) {
-        for (idx = 0; idx < thread_count; idx++) {
-            if (!decomp_param[idx].start) {
-                memcpy(decomp_param[idx].compbuf, compbuf, len);
-                decomp_param[idx].des = host;
-                decomp_param[idx].len = len;
-                start_decompression(&decomp_param[idx]);
-                break;
-            }
-        }
-        if (idx < thread_count) {
-            break;
-        }
-    }
-}
-
-static int ram_load(QEMUFile *f, void *opaque, int version_id)
-{
-    int flags = 0, ret = 0;
-    static uint64_t seq_iter;
-    int len = 0;
-
-    seq_iter++;
-
-    if (version_id != 4) {
-        ret = -EINVAL;
-    }
-
-    /* This RCU critical section can be very long running.
-     * When RCU reclaims in the code start to become numerous,
-     * it will be necessary to reduce the granularity of this
-     * critical section.
-     */
-    rcu_read_lock();
-    while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {
-        ram_addr_t addr, total_ram_bytes;
-        void *host;
-        uint8_t ch;
-
-        addr = qemu_get_be64(f);
-        flags = addr & ~TARGET_PAGE_MASK;
-        addr &= TARGET_PAGE_MASK;
-
-        switch (flags & ~RAM_SAVE_FLAG_CONTINUE) {
-        case RAM_SAVE_FLAG_MEM_SIZE:
-            /* Synchronize RAM block list */
-            total_ram_bytes = addr;
-            while (!ret && total_ram_bytes) {
-                RAMBlock *block;
-                uint8_t len;
-                char id[256];
-                ram_addr_t length;
-
-                len = qemu_get_byte(f);
-                qemu_get_buffer(f, (uint8_t *)id, len);
-                id[len] = 0;
-                length = qemu_get_be64(f);
-
-                QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
-                    if (!strncmp(id, block->idstr, sizeof(id))) {
-                        if (length != block->used_length) {
-                            Error *local_err = NULL;
-
-                            ret = qemu_ram_resize(block->offset, length, &local_err);
-                            if (local_err) {
-                                error_report_err(local_err);
-                            }
-                        }
-                        break;
-                    }
-                }
-
-                if (!block) {
-                    error_report("Unknown ramblock \"%s\", cannot "
-                                 "accept migration", id);
-                    ret = -EINVAL;
-                }
-
-                total_ram_bytes -= length;
-            }
-            break;
-        case RAM_SAVE_FLAG_COMPRESS:
-            host = host_from_stream_offset(f, addr, flags);
-            if (!host) {
-                error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
-                ret = -EINVAL;
-                break;
-            }
-            ch = qemu_get_byte(f);
-            ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);
-            break;
-        case RAM_SAVE_FLAG_PAGE:
-            host = host_from_stream_offset(f, addr, flags);
-            if (!host) {
-                error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
-                ret = -EINVAL;
-                break;
-            }
-            qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
-            break;
-        case RAM_SAVE_FLAG_COMPRESS_PAGE:
-            host = host_from_stream_offset(f, addr, flags);
-            if (!host) {
-                error_report("Invalid RAM offset " RAM_ADDR_FMT, addr);
-                ret = -EINVAL;
-                break;
-            }
-
-            len = qemu_get_be32(f);
-            if (len < 0 || len > compressBound(TARGET_PAGE_SIZE)) {
-                error_report("Invalid compressed data length: %d", len);
-                ret = -EINVAL;
-                break;
-            }
-            qemu_get_buffer(f, compressed_data_buf, len);
-            decompress_data_with_multi_threads(compressed_data_buf, host, len);
-            break;
-        case RAM_SAVE_FLAG_XBZRLE:
-            host = host_from_stream_offset(f, addr, flags);
-            if (!host) {
-                error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
-                ret = -EINVAL;
-                break;
-            }
-            if (load_xbzrle(f, addr, host) < 0) {
-                error_report("Failed to decompress XBZRLE page at "
-                             RAM_ADDR_FMT, addr);
-                ret = -EINVAL;
-                break;
-            }
-            break;
-        case RAM_SAVE_FLAG_EOS:
-            /* normal exit */
-            break;
-        default:
-            if (flags & RAM_SAVE_FLAG_HOOK) {
-                ram_control_load_hook(f, flags);
-            } else {
-                error_report("Unknown combination of migration flags: %#x",
-                             flags);
-                ret = -EINVAL;
-            }
-        }
-        if (!ret) {
-            ret = qemu_file_get_error(f);
-        }
-    }
-
-    rcu_read_unlock();
-    DPRINTF("Completed load of VM with exit code %d seq iteration "
-            "%" PRIu64 "\n", ret, seq_iter);
-    return ret;
-}
-
-static SaveVMHandlers savevm_ram_handlers = {
-    .save_live_setup = ram_save_setup,
-    .save_live_iterate = ram_save_iterate,
-    .save_live_complete = ram_save_complete,
-    .save_live_pending = ram_save_pending,
-    .load_state = ram_load,
-    .cancel = ram_migration_cancel,
-};
-
-void ram_mig_init(void)
-{
-    qemu_mutex_init(&XBZRLE.lock);
-    register_savevm_live(NULL, "ram", 0, 4, &savevm_ram_handlers, NULL);
-}
-
 struct soundhw {
     const char *name;
     const char *descr;
@@ -1869,52 +307,3 @@ TargetInfo *qmp_query_target(Error **errp)
 
     return info;
 }
-
-/* Stub function that's gets run on the vcpu when its brought out of the
-   VM to run inside qemu via async_run_on_cpu()*/
-static void mig_sleep_cpu(void *opq)
-{
-    qemu_mutex_unlock_iothread();
-    g_usleep(30*1000);
-    qemu_mutex_lock_iothread();
-}
-
-/* To reduce the dirty rate explicitly disallow the VCPUs from spending
-   much time in the VM. The migration thread will try to catchup.
-   Workload will experience a performance drop.
-*/
-static void mig_throttle_guest_down(void)
-{
-    CPUState *cpu;
-
-    qemu_mutex_lock_iothread();
-    CPU_FOREACH(cpu) {
-        async_run_on_cpu(cpu, mig_sleep_cpu, NULL);
-    }
-    qemu_mutex_unlock_iothread();
-}
-
-static void check_guest_throttling(void)
-{
-    static int64_t t0;
-    int64_t        t1;
-
-    if (!mig_throttle_on) {
-        return;
-    }
-
-    if (!t0)  {
-        t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
-        return;
-    }
-
-    t1 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
-
-    /* If it has been more than 40 ms since the last time the guest
-     * was throttled then do it again.
-     */
-    if (40 < (t1-t0)/1000000) {
-        mig_throttle_guest_down();
-        t0 = t1;
-    }
-}
diff --git a/cpus.c b/cpus.c
index f38b858f9b..b85fb5f03f 100644
--- a/cpus.c
+++ b/cpus.c
@@ -480,6 +480,7 @@ static const VMStateDescription icount_vmstate_timers = {
     .name = "timer/icount",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = icount_state_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT64(qemu_icount_bias, TimersState),
         VMSTATE_INT64(qemu_icount, TimersState),
@@ -497,13 +498,9 @@ static const VMStateDescription vmstate_timers = {
         VMSTATE_INT64_V(cpu_clock_offset, TimersState, 2),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &icount_vmstate_timers,
-            .needed = icount_state_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &icount_vmstate_timers,
+        NULL
     }
 };
 
diff --git a/docs/migration.txt b/docs/migration.txt
index 0492a4547a..f6df4beb2a 100644
--- a/docs/migration.txt
+++ b/docs/migration.txt
@@ -257,6 +257,7 @@ const VMStateDescription vmstate_ide_drive_pio_state = {
     .minimum_version_id = 1,
     .pre_save = ide_drive_pio_pre_save,
     .post_load = ide_drive_pio_post_load,
+    .needed = ide_drive_pio_state_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(req_nb_sectors, IDEState),
         VMSTATE_VARRAY_INT32(io_buffer, IDEState, io_buffer_total_len, 1,
@@ -279,13 +280,9 @@ const VMStateDescription vmstate_ide_drive = {
         .... several fields ....
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection []) {
-        {
-            .vmsd = &vmstate_ide_drive_pio_state,
-            .needed = ide_drive_pio_state_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_ide_drive_pio_state,
+        NULL
     }
 };
 
diff --git a/exec.c b/exec.c
index 487583b1bd..76bfc4ac4a 100644
--- a/exec.c
+++ b/exec.c
@@ -454,6 +454,7 @@ static const VMStateDescription vmstate_cpu_common_exception_index = {
     .name = "cpu_common/exception_index",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = cpu_common_exception_index_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(exception_index, CPUState),
         VMSTATE_END_OF_LIST()
@@ -471,13 +472,9 @@ const VMStateDescription vmstate_cpu_common = {
         VMSTATE_UINT32(interrupt_request, CPUState),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_cpu_common_exception_index,
-            .needed = cpu_common_exception_index_needed,
-        } , {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_cpu_common_exception_index,
+        NULL
     }
 };
 
@@ -3348,14 +3345,20 @@ bool cpu_physical_memory_is_io(hwaddr phys_addr)
     return res;
 }
 
-void qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque)
+int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque)
 {
     RAMBlock *block;
+    int ret = 0;
 
     rcu_read_lock();
     QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
-        func(block->host, block->offset, block->used_length, opaque);
+        ret = func(block->idstr, block->host, block->offset,
+                   block->used_length, opaque);
+        if (ret) {
+            break;
+        }
     }
     rcu_read_unlock();
+    return ret;
 }
 #endif
diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c
index 25bc023882..8a64ffb38f 100644
--- a/hw/acpi/ich9.c
+++ b/hw/acpi/ich9.c
@@ -152,6 +152,7 @@ static const VMStateDescription vmstate_memhp_state = {
     .version_id = 1,
     .minimum_version_id = 1,
     .minimum_version_id_old = 1,
+    .needed = vmstate_test_use_memhp,
     .fields      = (VMStateField[]) {
         VMSTATE_MEMORY_HOTPLUG(acpi_memory_hotplug, ICH9LPCPMRegs),
         VMSTATE_END_OF_LIST()
@@ -175,12 +176,9 @@ const VMStateDescription vmstate_ich9_pm = {
         VMSTATE_UINT32(smi_sts, ICH9LPCPMRegs),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_memhp_state,
-            .needed = vmstate_test_use_memhp,
-        },
-        VMSTATE_END_OF_LIST()
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_memhp_state,
+        NULL
     }
 };
 
diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index b730ca6ced..3bd1d5a865 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -260,6 +260,7 @@ static const VMStateDescription vmstate_memhp_state = {
     .version_id = 1,
     .minimum_version_id = 1,
     .minimum_version_id_old = 1,
+    .needed = vmstate_test_use_memhp,
     .fields      = (VMStateField[]) {
         VMSTATE_MEMORY_HOTPLUG(acpi_memory_hotplug, PIIX4PMState),
         VMSTATE_END_OF_LIST()
@@ -298,12 +299,9 @@ static const VMStateDescription vmstate_acpi = {
                             vmstate_test_use_acpi_pci_hotplug),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_memhp_state,
-            .needed = vmstate_test_use_memhp,
-        },
-        VMSTATE_END_OF_LIST()
+    .subsections = (const VMStateDescription*[]) {
+         &vmstate_memhp_state,
+         NULL
     }
 };
 
diff --git a/hw/block/fdc.c b/hw/block/fdc.c
index 6e794597dc..5e1b67ee43 100644
--- a/hw/block/fdc.c
+++ b/hw/block/fdc.c
@@ -699,6 +699,7 @@ static const VMStateDescription vmstate_fdrive_media_changed = {
     .name = "fdrive/media_changed",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = fdrive_media_changed_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(media_changed, FDrive),
         VMSTATE_END_OF_LIST()
@@ -716,6 +717,7 @@ static const VMStateDescription vmstate_fdrive_media_rate = {
     .name = "fdrive/media_rate",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = fdrive_media_rate_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(media_rate, FDrive),
         VMSTATE_END_OF_LIST()
@@ -733,6 +735,7 @@ static const VMStateDescription vmstate_fdrive_perpendicular = {
     .name = "fdrive/perpendicular",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = fdrive_perpendicular_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(perpendicular, FDrive),
         VMSTATE_END_OF_LIST()
@@ -756,19 +759,11 @@ static const VMStateDescription vmstate_fdrive = {
         VMSTATE_UINT8(sect, FDrive),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_fdrive_media_changed,
-            .needed = &fdrive_media_changed_needed,
-        } , {
-            .vmsd = &vmstate_fdrive_media_rate,
-            .needed = &fdrive_media_rate_needed,
-        } , {
-            .vmsd = &vmstate_fdrive_perpendicular,
-            .needed = &fdrive_perpendicular_needed,
-        } , {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_fdrive_media_changed,
+        &vmstate_fdrive_media_rate,
+        &vmstate_fdrive_perpendicular,
+        NULL
     }
 };
 
@@ -833,6 +828,7 @@ static const VMStateDescription vmstate_fdc_reset_sensei = {
     .name = "fdc/reset_sensei",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = fdc_reset_sensei_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(reset_sensei, FDCtrl),
         VMSTATE_END_OF_LIST()
@@ -850,6 +846,7 @@ static const VMStateDescription vmstate_fdc_result_timer = {
     .name = "fdc/result_timer",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = fdc_result_timer_needed,
     .fields = (VMStateField[]) {
         VMSTATE_TIMER_PTR(result_timer, FDCtrl),
         VMSTATE_END_OF_LIST()
@@ -867,6 +864,7 @@ static const VMStateDescription vmstate_fdc_phase = {
     .name = "fdc/phase",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = fdc_phase_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(phase, FDCtrl),
         VMSTATE_END_OF_LIST()
@@ -911,19 +909,11 @@ static const VMStateDescription vmstate_fdc = {
                              vmstate_fdrive, FDrive),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_fdc_reset_sensei,
-            .needed = fdc_reset_sensei_needed,
-        } , {
-            .vmsd = &vmstate_fdc_result_timer,
-            .needed = fdc_result_timer_needed,
-        } , {
-            .vmsd = &vmstate_fdc_phase,
-            .needed = fdc_phase_needed,
-        } , {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_fdc_reset_sensei,
+        &vmstate_fdc_result_timer,
+        &vmstate_fdc_phase,
+        NULL
     }
 };
 
diff --git a/hw/char/serial.c b/hw/char/serial.c
index 55011cfd26..513d73c27f 100644
--- a/hw/char/serial.c
+++ b/hw/char/serial.c
@@ -662,6 +662,7 @@ static const VMStateDescription vmstate_serial_thr_ipending = {
     .name = "serial/thr_ipending",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = serial_thr_ipending_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(thr_ipending, SerialState),
         VMSTATE_END_OF_LIST()
@@ -678,6 +679,7 @@ static const VMStateDescription vmstate_serial_tsr = {
     .name = "serial/tsr",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = serial_tsr_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(tsr_retry, SerialState),
         VMSTATE_UINT8(thr, SerialState),
@@ -697,6 +699,7 @@ static const VMStateDescription vmstate_serial_recv_fifo = {
     .name = "serial/recv_fifo",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = serial_recv_fifo_needed,
     .fields = (VMStateField[]) {
         VMSTATE_STRUCT(recv_fifo, SerialState, 1, vmstate_fifo8, Fifo8),
         VMSTATE_END_OF_LIST()
@@ -713,6 +716,7 @@ static const VMStateDescription vmstate_serial_xmit_fifo = {
     .name = "serial/xmit_fifo",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = serial_xmit_fifo_needed,
     .fields = (VMStateField[]) {
         VMSTATE_STRUCT(xmit_fifo, SerialState, 1, vmstate_fifo8, Fifo8),
         VMSTATE_END_OF_LIST()
@@ -729,6 +733,7 @@ static const VMStateDescription vmstate_serial_fifo_timeout_timer = {
     .name = "serial/fifo_timeout_timer",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = serial_fifo_timeout_timer_needed,
     .fields = (VMStateField[]) {
         VMSTATE_TIMER_PTR(fifo_timeout_timer, SerialState),
         VMSTATE_END_OF_LIST()
@@ -745,6 +750,7 @@ static const VMStateDescription vmstate_serial_timeout_ipending = {
     .name = "serial/timeout_ipending",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = serial_timeout_ipending_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(timeout_ipending, SerialState),
         VMSTATE_END_OF_LIST()
@@ -760,6 +766,7 @@ static bool serial_poll_needed(void *opaque)
 static const VMStateDescription vmstate_serial_poll = {
     .name = "serial/poll",
     .version_id = 1,
+    .needed = serial_poll_needed,
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(poll_msl, SerialState),
@@ -788,31 +795,15 @@ const VMStateDescription vmstate_serial = {
         VMSTATE_UINT8_V(fcr_vmstate, SerialState, 3),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_serial_thr_ipending,
-            .needed = &serial_thr_ipending_needed,
-        } , {
-            .vmsd = &vmstate_serial_tsr,
-            .needed = &serial_tsr_needed,
-        } , {
-            .vmsd = &vmstate_serial_recv_fifo,
-            .needed = &serial_recv_fifo_needed,
-        } , {
-            .vmsd = &vmstate_serial_xmit_fifo,
-            .needed = &serial_xmit_fifo_needed,
-        } , {
-            .vmsd = &vmstate_serial_fifo_timeout_timer,
-            .needed = &serial_fifo_timeout_timer_needed,
-        } , {
-            .vmsd = &vmstate_serial_timeout_ipending,
-            .needed = &serial_timeout_ipending_needed,
-        } , {
-            .vmsd = &vmstate_serial_poll,
-            .needed = &serial_poll_needed,
-        } , {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_serial_thr_ipending,
+        &vmstate_serial_tsr,
+        &vmstate_serial_recv_fifo,
+        &vmstate_serial_xmit_fifo,
+        &vmstate_serial_fifo_timeout_timer,
+        &vmstate_serial_timeout_ipending,
+        &vmstate_serial_poll,
+        NULL
     }
 };
 
diff --git a/hw/display/qxl.c b/hw/display/qxl.c
index b220e2d5d2..722146ec3a 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -2220,6 +2220,7 @@ static VMStateDescription qxl_vmstate_monitors_config = {
     .name               = "qxl/monitors-config",
     .version_id         = 1,
     .minimum_version_id = 1,
+    .needed = qxl_monitors_config_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(guest_monitors_config, PCIQXLDevice),
         VMSTATE_END_OF_LIST()
@@ -2253,13 +2254,9 @@ static VMStateDescription qxl_vmstate = {
         VMSTATE_UINT64(guest_cursor, PCIQXLDevice),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &qxl_vmstate_monitors_config,
-            .needed = qxl_monitors_config_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &qxl_vmstate_monitors_config,
+        NULL
     }
 };
 
diff --git a/hw/display/vga.c b/hw/display/vga.c
index d1d296c74e..b35d523e65 100644
--- a/hw/display/vga.c
+++ b/hw/display/vga.c
@@ -2035,6 +2035,7 @@ static const VMStateDescription vmstate_vga_endian = {
     .name = "vga.endian",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = vga_endian_state_needed,
     .fields = (VMStateField[]) {
         VMSTATE_BOOL(big_endian_fb, VGACommonState),
         VMSTATE_END_OF_LIST()
@@ -2078,13 +2079,9 @@ const VMStateDescription vmstate_vga_common = {
         VMSTATE_UINT32(vbe_bank_mask, VGACommonState),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection []) {
-        {
-            .vmsd = &vmstate_vga_endian,
-            .needed = vga_endian_state_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_vga_endian,
+        NULL
     }
 };
 
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 5253e6d4fa..e142f75649 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -52,6 +52,7 @@
 #ifdef CONFIG_XEN
 #  include <xen/hvm/hvm_info_table.h>
 #endif
+#include "migration/migration.h"
 
 #define MAX_IDE_BUS 2
 
@@ -305,6 +306,7 @@ static void pc_init1(MachineState *machine)
 
 static void pc_compat_2_3(MachineState *machine)
 {
+    savevm_skip_section_footers();
 }
 
 static void pc_compat_2_2(MachineState *machine)
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 110dfb78a8..b68263d231 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -45,6 +45,7 @@
 #include "hw/usb.h"
 #include "hw/cpu/icc_bus.h"
 #include "qemu/error-report.h"
+#include "migration/migration.h"
 
 /* ICH9 AHCI has 6 ports */
 #define MAX_SATA_PORTS     6
@@ -289,6 +290,7 @@ static void pc_q35_init(MachineState *machine)
 
 static void pc_compat_2_3(MachineState *machine)
 {
+    savevm_skip_section_footers();
 }
 
 static void pc_compat_2_2(MachineState *machine)
diff --git a/hw/ide/core.c b/hw/ide/core.c
index fcb908061c..1efd98af63 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -2561,6 +2561,7 @@ static const VMStateDescription vmstate_ide_atapi_gesn_state = {
     .name ="ide_drive/atapi/gesn_state",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = ide_atapi_gesn_needed,
     .fields = (VMStateField[]) {
         VMSTATE_BOOL(events.new_media, IDEState),
         VMSTATE_BOOL(events.eject_request, IDEState),
@@ -2572,6 +2573,7 @@ static const VMStateDescription vmstate_ide_tray_state = {
     .name = "ide_drive/tray_state",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = ide_tray_state_needed,
     .fields = (VMStateField[]) {
         VMSTATE_BOOL(tray_open, IDEState),
         VMSTATE_BOOL(tray_locked, IDEState),
@@ -2585,6 +2587,7 @@ static const VMStateDescription vmstate_ide_drive_pio_state = {
     .minimum_version_id = 1,
     .pre_save = ide_drive_pio_pre_save,
     .post_load = ide_drive_pio_post_load,
+    .needed = ide_drive_pio_state_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(req_nb_sectors, IDEState),
         VMSTATE_VARRAY_INT32(io_buffer, IDEState, io_buffer_total_len, 1,
@@ -2626,19 +2629,11 @@ const VMStateDescription vmstate_ide_drive = {
         VMSTATE_UINT8_V(cdrom_changed, IDEState, 3),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection []) {
-        {
-            .vmsd = &vmstate_ide_drive_pio_state,
-            .needed = ide_drive_pio_state_needed,
-        }, {
-            .vmsd = &vmstate_ide_tray_state,
-            .needed = ide_tray_state_needed,
-        }, {
-            .vmsd = &vmstate_ide_atapi_gesn_state,
-            .needed = ide_atapi_gesn_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_ide_drive_pio_state,
+        &vmstate_ide_tray_state,
+        &vmstate_ide_atapi_gesn_state,
+        NULL
     }
 };
 
@@ -2646,6 +2641,7 @@ static const VMStateDescription vmstate_ide_error_status = {
     .name ="ide_bus/error",
     .version_id = 2,
     .minimum_version_id = 1,
+    .needed = ide_error_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(error_status, IDEBus),
         VMSTATE_INT64_V(retry_sector_num, IDEBus, 2),
@@ -2664,13 +2660,9 @@ const VMStateDescription vmstate_ide_bus = {
         VMSTATE_UINT8(unit, IDEBus),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection []) {
-        {
-            .vmsd = &vmstate_ide_error_status,
-            .needed = ide_error_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_ide_error_status,
+        NULL
     }
 };
 
diff --git a/hw/ide/pci.c b/hw/ide/pci.c
index 4b5e32dcbe..4afd0cfe8c 100644
--- a/hw/ide/pci.c
+++ b/hw/ide/pci.c
@@ -350,6 +350,7 @@ static const VMStateDescription vmstate_bmdma_current = {
     .name = "ide bmdma_current",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = ide_bmdma_current_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(cur_addr, BMDMAState),
         VMSTATE_UINT32(cur_prd_last, BMDMAState),
@@ -363,6 +364,7 @@ static const VMStateDescription vmstate_bmdma_status = {
     .name ="ide bmdma/status",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = ide_bmdma_status_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(status, BMDMAState),
         VMSTATE_END_OF_LIST()
@@ -383,16 +385,10 @@ static const VMStateDescription vmstate_bmdma = {
         VMSTATE_UINT8(migration_retry_unit, BMDMAState),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection []) {
-        {
-            .vmsd = &vmstate_bmdma_current,
-            .needed = ide_bmdma_current_needed,
-        }, {
-            .vmsd = &vmstate_bmdma_status,
-            .needed = ide_bmdma_status_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_bmdma_current,
+        &vmstate_bmdma_status,
+        NULL
     }
 };
 
diff --git a/hw/input/pckbd.c b/hw/input/pckbd.c
index 9b9a7d7a8a..ddac69df6f 100644
--- a/hw/input/pckbd.c
+++ b/hw/input/pckbd.c
@@ -391,23 +391,24 @@ static int kbd_outport_post_load(void *opaque, int version_id)
     return 0;
 }
 
+static bool kbd_outport_needed(void *opaque)
+{
+    KBDState *s = opaque;
+    return s->outport != kbd_outport_default(s);
+}
+
 static const VMStateDescription vmstate_kbd_outport = {
     .name = "pckbd_outport",
     .version_id = 1,
     .minimum_version_id = 1,
     .post_load = kbd_outport_post_load,
+    .needed = kbd_outport_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(outport, KBDState),
         VMSTATE_END_OF_LIST()
     }
 };
 
-static bool kbd_outport_needed(void *opaque)
-{
-    KBDState *s = opaque;
-    return s->outport != kbd_outport_default(s);
-}
-
 static int kbd_post_load(void *opaque, int version_id)
 {
     KBDState *s = opaque;
@@ -430,12 +431,9 @@ static const VMStateDescription vmstate_kbd = {
         VMSTATE_UINT8(pending, KBDState),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_kbd_outport,
-            .needed = kbd_outport_needed,
-        },
-        VMSTATE_END_OF_LIST()
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_kbd_outport,
+        NULL
     }
 };
 
diff --git a/hw/input/ps2.c b/hw/input/ps2.c
index 4baeea2b56..fdbe565e62 100644
--- a/hw/input/ps2.c
+++ b/hw/input/ps2.c
@@ -677,6 +677,7 @@ static const VMStateDescription vmstate_ps2_keyboard_ledstate = {
     .version_id = 3,
     .minimum_version_id = 2,
     .post_load = ps2_kbd_ledstate_post_load,
+    .needed = ps2_keyboard_ledstate_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(ledstate, PS2KbdState),
         VMSTATE_END_OF_LIST()
@@ -717,13 +718,9 @@ static const VMStateDescription vmstate_ps2_keyboard = {
         VMSTATE_INT32_V(scancode_set, PS2KbdState,3),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection []) {
-        {
-            .vmsd = &vmstate_ps2_keyboard_ledstate,
-            .needed = ps2_keyboard_ledstate_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_ps2_keyboard_ledstate,
+        NULL
     }
 };
 
diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c
index d595d63a51..0032b97c5f 100644
--- a/hw/intc/apic_common.c
+++ b/hw/intc/apic_common.c
@@ -369,6 +369,7 @@ static const VMStateDescription vmstate_apic_common_sipi = {
     .name = "apic_sipi",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = apic_common_sipi_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(sipi_vector, APICCommonState),
         VMSTATE_INT32(wait_for_sipi, APICCommonState),
@@ -408,12 +409,9 @@ static const VMStateDescription vmstate_apic_common = {
                       APICCommonState), /* open-coded timer state */
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_apic_common_sipi,
-            .needed = apic_common_sipi_needed,
-        },
-        VMSTATE_END_OF_LIST()
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_apic_common_sipi,
+        NULL
     }
 };
 
diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
index 71a9f7a716..b3e0b1fd52 100644
--- a/hw/isa/lpc_ich9.c
+++ b/hw/isa/lpc_ich9.c
@@ -650,6 +650,7 @@ static const VMStateDescription vmstate_ich9_rst_cnt = {
     .name = "ICH9LPC/rst_cnt",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = ich9_rst_cnt_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(rst_cnt, ICH9LPCState),
         VMSTATE_END_OF_LIST()
@@ -669,12 +670,9 @@ static const VMStateDescription vmstate_ich9_lpc = {
         VMSTATE_UINT32(sci_level, ICH9LPCState),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_ich9_rst_cnt,
-            .needed = ich9_rst_cnt_needed
-        },
-        { 0 }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_ich9_rst_cnt,
+        NULL
     }
 };
 
diff --git a/hw/net/e1000.c b/hw/net/e1000.c
index 091d61acc3..bab8e2abfb 100644
--- a/hw/net/e1000.c
+++ b/hw/net/e1000.c
@@ -1370,6 +1370,7 @@ static const VMStateDescription vmstate_e1000_mit_state = {
     .name = "e1000/mit_state",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = e1000_mit_state_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(mac_reg[RDTR], E1000State),
         VMSTATE_UINT32(mac_reg[RADV], E1000State),
@@ -1457,13 +1458,9 @@ static const VMStateDescription vmstate_e1000 = {
         VMSTATE_UINT32_SUB_ARRAY(mac_reg, E1000State, VFTA, 128),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_e1000_mit_state,
-            .needed = e1000_mit_state_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_e1000_mit_state,
+        NULL
     }
 };
 
diff --git a/hw/net/rtl8139.c b/hw/net/rtl8139.c
index f868108dfe..e0db4727ae 100644
--- a/hw/net/rtl8139.c
+++ b/hw/net/rtl8139.c
@@ -3240,6 +3240,7 @@ static const VMStateDescription vmstate_rtl8139_hotplug_ready ={
     .name = "rtl8139/hotplug_ready",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = rtl8139_hotplug_ready_needed,
     .fields = (VMStateField[]) {
         VMSTATE_END_OF_LIST()
     }
@@ -3335,13 +3336,9 @@ static const VMStateDescription vmstate_rtl8139 = {
         VMSTATE_UINT32_V(cplus_enabled, RTL8139State, 4),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection []) {
-        {
-            .vmsd = &vmstate_rtl8139_hotplug_ready,
-            .needed = rtl8139_hotplug_ready_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_rtl8139_hotplug_ready,
+        NULL
     }
 };
 
diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c
index dfb328debd..8bcdf3ed77 100644
--- a/hw/net/vmxnet3.c
+++ b/hw/net/vmxnet3.c
@@ -2226,6 +2226,7 @@ static const VMStateDescription vmxstate_vmxnet3_mcast_list = {
     .version_id = 1,
     .minimum_version_id = 1,
     .pre_load = vmxnet3_mcast_list_pre_load,
+    .needed = vmxnet3_mc_list_needed,
     .fields = (VMStateField[]) {
         VMSTATE_VBUFFER_UINT32(mcast_list, VMXNET3State, 0, NULL, 0,
             mcast_list_buff_size),
@@ -2470,14 +2471,9 @@ static const VMStateDescription vmstate_vmxnet3 = {
 
             VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmxstate_vmxnet3_mcast_list,
-            .needed = vmxnet3_mc_list_needed
-        },
-        {
-            /* empty element. */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmxstate_vmxnet3_mcast_list,
+        NULL
     }
 };
 
diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
index f1712b86fe..ed2424c4cd 100644
--- a/hw/pci-host/piix.c
+++ b/hw/pci-host/piix.c
@@ -582,6 +582,7 @@ static const VMStateDescription vmstate_piix3_rcr = {
     .name = "PIIX3/rcr",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = piix3_rcr_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(rcr, PIIX3State),
         VMSTATE_END_OF_LIST()
@@ -600,12 +601,9 @@ static const VMStateDescription vmstate_piix3 = {
                               PIIX_NUM_PIRQS, 3),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_piix3_rcr,
-            .needed = piix3_rcr_needed,
-        },
-        { 0 }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_piix3_rcr,
+        NULL
     }
 };
 
diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
index bd2c0e4caa..f50b2f08af 100644
--- a/hw/scsi/scsi-bus.c
+++ b/hw/scsi/scsi-bus.c
@@ -1968,6 +1968,7 @@ static const VMStateDescription vmstate_scsi_sense_state = {
     .name = "SCSIDevice/sense",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = scsi_sense_state_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8_SUB_ARRAY(sense, SCSIDevice,
                                 SCSI_SENSE_BUF_SIZE_OLD,
@@ -1998,13 +1999,9 @@ const VMStateDescription vmstate_scsi_device = {
         },
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection []) {
-        {
-            .vmsd = &vmstate_scsi_sense_state,
-            .needed = scsi_sense_state_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_scsi_sense_state,
+        NULL
     }
 };
 
diff --git a/hw/timer/hpet.c b/hw/timer/hpet.c
index b6b8a2063d..b50071ef93 100644
--- a/hw/timer/hpet.c
+++ b/hw/timer/hpet.c
@@ -283,6 +283,7 @@ static const VMStateDescription vmstate_hpet_rtc_irq_level = {
     .name = "hpet/rtc_irq_level",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = hpet_rtc_irq_level_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(rtc_irq_level, HPETState),
         VMSTATE_END_OF_LIST()
@@ -322,13 +323,9 @@ static const VMStateDescription vmstate_hpet = {
                                     vmstate_hpet_timer, HPETTimer),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_hpet_rtc_irq_level,
-            .needed = hpet_rtc_irq_level_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_hpet_rtc_irq_level,
+        NULL
     }
 };
 
diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c
index f2b77fa118..32048258c9 100644
--- a/hw/timer/mc146818rtc.c
+++ b/hw/timer/mc146818rtc.c
@@ -733,22 +733,23 @@ static int rtc_post_load(void *opaque, int version_id)
     return 0;
 }
 
+static bool rtc_irq_reinject_on_ack_count_needed(void *opaque)
+{
+    RTCState *s = (RTCState *)opaque;
+    return s->irq_reinject_on_ack_count != 0;
+}
+
 static const VMStateDescription vmstate_rtc_irq_reinject_on_ack_count = {
     .name = "mc146818rtc/irq_reinject_on_ack_count",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = rtc_irq_reinject_on_ack_count_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT16(irq_reinject_on_ack_count, RTCState),
         VMSTATE_END_OF_LIST()
     }
 };
 
-static bool rtc_irq_reinject_on_ack_count_needed(void *opaque)
-{
-    RTCState *s = (RTCState *)opaque;
-    return s->irq_reinject_on_ack_count != 0;
-}
-
 static const VMStateDescription vmstate_rtc = {
     .name = "mc146818rtc",
     .version_id = 3,
@@ -770,13 +771,9 @@ static const VMStateDescription vmstate_rtc = {
         VMSTATE_UINT64_V(next_alarm_time, RTCState, 3),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_rtc_irq_reinject_on_ack_count,
-            .needed = rtc_irq_reinject_on_ack_count_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_rtc_irq_reinject_on_ack_count,
+        NULL
     }
 };
 
diff --git a/hw/usb/hcd-ohci.c b/hw/usb/hcd-ohci.c
index 1a22c9c0cb..7d65818064 100644
--- a/hw/usb/hcd-ohci.c
+++ b/hw/usb/hcd-ohci.c
@@ -2034,6 +2034,7 @@ static const VMStateDescription vmstate_ohci_eof_timer = {
     .version_id = 1,
     .minimum_version_id = 1,
     .pre_load = ohci_eof_timer_pre_load,
+    .needed = ohci_eof_timer_needed,
     .fields = (VMStateField[]) {
         VMSTATE_TIMER_PTR(eof_timer, OHCIState),
         VMSTATE_END_OF_LIST()
@@ -2081,13 +2082,9 @@ static const VMStateDescription vmstate_ohci_state = {
         VMSTATE_BOOL(async_complete, OHCIState),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection []) {
-        {
-            .vmsd = &vmstate_ohci_eof_timer,
-            .needed = ohci_eof_timer_needed,
-        } , {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_ohci_eof_timer,
+        NULL
     }
 };
 
diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c
index 242a654583..6b4218c037 100644
--- a/hw/usb/redirect.c
+++ b/hw/usb/redirect.c
@@ -2257,40 +2257,42 @@ static const VMStateInfo usbredir_ep_bufpq_vmstate_info = {
 
 
 /* For endp_data migration */
+static bool usbredir_bulk_receiving_needed(void *priv)
+{
+    struct endp_data *endp = priv;
+
+    return endp->bulk_receiving_started;
+}
+
 static const VMStateDescription usbredir_bulk_receiving_vmstate = {
     .name = "usb-redir-ep/bulk-receiving",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = usbredir_bulk_receiving_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(bulk_receiving_started, struct endp_data),
         VMSTATE_END_OF_LIST()
     }
 };
 
-static bool usbredir_bulk_receiving_needed(void *priv)
+static bool usbredir_stream_needed(void *priv)
 {
     struct endp_data *endp = priv;
 
-    return endp->bulk_receiving_started;
+    return endp->max_streams;
 }
 
 static const VMStateDescription usbredir_stream_vmstate = {
     .name = "usb-redir-ep/stream-state",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = usbredir_stream_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(max_streams, struct endp_data),
         VMSTATE_END_OF_LIST()
     }
 };
 
-static bool usbredir_stream_needed(void *priv)
-{
-    struct endp_data *endp = priv;
-
-    return endp->max_streams;
-}
-
 static const VMStateDescription usbredir_ep_vmstate = {
     .name = "usb-redir-ep",
     .version_id = 1,
@@ -2318,16 +2320,10 @@ static const VMStateDescription usbredir_ep_vmstate = {
         VMSTATE_INT32(bufpq_target_size, struct endp_data),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &usbredir_bulk_receiving_vmstate,
-            .needed = usbredir_bulk_receiving_needed,
-        }, {
-            .vmsd = &usbredir_stream_vmstate,
-            .needed = usbredir_stream_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &usbredir_bulk_receiving_vmstate,
+        &usbredir_stream_vmstate,
+        NULL
     }
 };
 
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index fb49ffcb2d..ee4e07c5e7 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -1053,6 +1053,7 @@ static const VMStateDescription vmstate_virtio_device_endian = {
     .name = "virtio/device_endian",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = &virtio_device_endian_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(device_endian, VirtIODevice),
         VMSTATE_END_OF_LIST()
@@ -1063,6 +1064,7 @@ static const VMStateDescription vmstate_virtio_64bit_features = {
     .name = "virtio/64bit_features",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = &virtio_64bit_features_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(guest_features, VirtIODevice),
         VMSTATE_END_OF_LIST()
@@ -1077,16 +1079,10 @@ static const VMStateDescription vmstate_virtio = {
     .fields = (VMStateField[]) {
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_virtio_device_endian,
-            .needed = &virtio_device_endian_needed
-        },
-        {
-            .vmsd = &vmstate_virtio_64bit_features,
-            .needed = &virtio_64bit_features_needed
-        },
-        { 0 }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_virtio_device_endian,
+        &vmstate_virtio_64bit_features,
+        NULL
     }
 };
 
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 43428bd030..de8a7200a9 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -126,10 +126,10 @@ void cpu_flush_icache_range(hwaddr start, int len);
 extern struct MemoryRegion io_mem_rom;
 extern struct MemoryRegion io_mem_notdirty;
 
-typedef void (RAMBlockIterFunc)(void *host_addr,
+typedef int (RAMBlockIterFunc)(const char *block_name, void *host_addr,
     ram_addr_t offset, ram_addr_t length, void *opaque);
 
-void qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque);
+int qemu_ram_foreach_block(RAMBlockIterFunc func, void *opaque);
 
 #endif
 
diff --git a/include/migration/migration.h b/include/migration/migration.h
index a6e025a248..9387c8c9d4 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -34,6 +34,7 @@
 #define QEMU_VM_SECTION_FULL         0x04
 #define QEMU_VM_SUBSECTION           0x05
 #define QEMU_VM_VMDESCRIPTION        0x06
+#define QEMU_VM_SECTION_FOOTER       0x7e
 
 struct MigrationParams {
     bool blk;
@@ -42,6 +43,20 @@ struct MigrationParams {
 
 typedef struct MigrationState MigrationState;
 
+typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
+
+/* State for the incoming migration */
+struct MigrationIncomingState {
+    QEMUFile *file;
+
+    /* See savevm.c */
+    LoadStateEntry_Head loadvm_handlers;
+};
+
+MigrationIncomingState *migration_incoming_get_current(void);
+MigrationIncomingState *migration_incoming_state_new(QEMUFile *f);
+void migration_incoming_state_destroy(void);
+
 struct MigrationState
 {
     int64_t bandwidth_limit;
@@ -180,4 +195,6 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
                              ram_addr_t offset, size_t size,
                              uint64_t *bytes_sent);
 
+void ram_mig_init(void);
+void savevm_skip_section_footers(void);
 #endif
diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
index a01c5b817e..4f67d79227 100644
--- a/include/migration/qemu-file.h
+++ b/include/migration/qemu-file.h
@@ -157,7 +157,7 @@ static inline void qemu_put_ubyte(QEMUFile *f, unsigned int v)
 void qemu_put_be16(QEMUFile *f, unsigned int v);
 void qemu_put_be32(QEMUFile *f, unsigned int v);
 void qemu_put_be64(QEMUFile *f, uint64_t v);
-int qemu_peek_buffer(QEMUFile *f, uint8_t *buf, int size, size_t offset);
+int qemu_peek_buffer(QEMUFile *f, uint8_t **buf, int size, size_t offset);
 int qemu_get_buffer(QEMUFile *f, uint8_t *buf, int size);
 ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
                                   int level);
@@ -312,4 +312,7 @@ static inline void qemu_get_sbe64s(QEMUFile *f, int64_t *pv)
 {
     qemu_get_be64s(f, (uint64_t *)pv);
 }
+
+size_t qemu_get_counted_string(QEMUFile *f, char buf[256]);
+
 #endif
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index bc7616aaa8..7153b1e145 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -120,11 +120,6 @@ typedef struct {
     bool (*field_exists)(void *opaque, int version_id);
 } VMStateField;
 
-typedef struct VMStateSubsection {
-    const VMStateDescription *vmsd;
-    bool (*needed)(void *opaque);
-} VMStateSubsection;
-
 struct VMStateDescription {
     const char *name;
     int unmigratable;
@@ -135,8 +130,9 @@ struct VMStateDescription {
     int (*pre_load)(void *opaque);
     int (*post_load)(void *opaque, int version_id);
     void (*pre_save)(void *opaque);
+    bool (*needed)(void *opaque);
     VMStateField *fields;
-    const VMStateSubsection *subsections;
+    const VMStateDescription **subsections;
 };
 
 extern const VMStateDescription vmstate_dummy;
@@ -812,6 +808,8 @@ extern const VMStateInfo vmstate_info_bitmap;
 
 #define SELF_ANNOUNCE_ROUNDS 5
 
+void loadvm_free_handlers(MigrationIncomingState *mis);
+
 int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
                        void *opaque, int version_id);
 void vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd,
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index cde3314896..6fdcbcd524 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -31,6 +31,7 @@ typedef struct I2CBus I2CBus;
 typedef struct I2SCodec I2SCodec;
 typedef struct ISABus ISABus;
 typedef struct ISADevice ISADevice;
+typedef struct LoadStateEntry LoadStateEntry;
 typedef struct MACAddr MACAddr;
 typedef struct MachineClass MachineClass;
 typedef struct MachineState MachineState;
@@ -38,6 +39,7 @@ typedef struct MemoryListener MemoryListener;
 typedef struct MemoryMappingList MemoryMappingList;
 typedef struct MemoryRegion MemoryRegion;
 typedef struct MemoryRegionSection MemoryRegionSection;
+typedef struct MigrationIncomingState MigrationIncomingState;
 typedef struct MigrationParams MigrationParams;
 typedef struct Monitor Monitor;
 typedef struct MouseTransformInfo MouseTransformInfo;
diff --git a/include/sysemu/arch_init.h b/include/sysemu/arch_init.h
index 54b36c16c4..c38892fec6 100644
--- a/include/sysemu/arch_init.h
+++ b/include/sysemu/arch_init.h
@@ -30,7 +30,6 @@ extern const uint32_t arch_type;
 void select_soundhw(const char *optarg);
 void do_acpitable_option(const QemuOpts *opts);
 void do_smbios_option(QemuOpts *opts);
-void ram_mig_init(void);
 void cpudef_init(void);
 void audio_init(void);
 int kvm_available(void);
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 853d90a317..ef793f702e 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -84,6 +84,7 @@ void qemu_announce_self(void);
 bool qemu_savevm_state_blocked(Error **errp);
 void qemu_savevm_state_begin(QEMUFile *f,
                              const MigrationParams *params);
+void qemu_savevm_state_header(QEMUFile *f);
 int qemu_savevm_state_iterate(QEMUFile *f);
 void qemu_savevm_state_complete(QEMUFile *f);
 void qemu_savevm_state_cancel(void);
diff --git a/migration/migration.c b/migration/migration.c
index 732d229708..b04b4571a8 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -53,6 +53,7 @@ static bool deferred_incoming;
    migrations at once.  For now we don't need to add
    dynamic creation of migration */
 
+/* For outgoing */
 MigrationState *migrate_get_current(void)
 {
     static MigrationState current_migration = {
@@ -71,6 +72,30 @@ MigrationState *migrate_get_current(void)
     return &current_migration;
 }
 
+/* For incoming */
+static MigrationIncomingState *mis_current;
+
+MigrationIncomingState *migration_incoming_get_current(void)
+{
+    return mis_current;
+}
+
+MigrationIncomingState *migration_incoming_state_new(QEMUFile* f)
+{
+    mis_current = g_malloc0(sizeof(MigrationIncomingState));
+    mis_current->file = f;
+    QLIST_INIT(&mis_current->loadvm_handlers);
+
+    return mis_current;
+}
+
+void migration_incoming_state_destroy(void)
+{
+    loadvm_free_handlers(mis_current);
+    g_free(mis_current);
+    mis_current = NULL;
+}
+
 /*
  * Called on -incoming with a defer: uri.
  * The migration can be started later after any parameters have been
@@ -115,9 +140,14 @@ static void process_incoming_migration_co(void *opaque)
     Error *local_err = NULL;
     int ret;
 
+    migration_incoming_state_new(f);
+
     ret = qemu_loadvm_state(f);
+
     qemu_fclose(f);
     free_xbzrle_decoded_buf();
+    migration_incoming_state_destroy();
+
     if (ret < 0) {
         error_report("load of migration failed: %s", strerror(-ret));
         migrate_decompress_threads_join();
@@ -738,6 +768,7 @@ static void *migration_thread(void *opaque)
     int64_t start_time = initial_time;
     bool old_vm_running = false;
 
+    qemu_savevm_state_header(s->file);
     qemu_savevm_state_begin(s->file, &s->params);
 
     s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
@@ -838,9 +869,6 @@ static void *migration_thread(void *opaque)
 
 void migrate_fd_connect(MigrationState *s)
 {
-    s->state = MIGRATION_STATUS_SETUP;
-    trace_migrate_set_state(MIGRATION_STATUS_SETUP);
-
     /* This is a best 1st approximation. ns to ms */
     s->expected_downtime = max_downtime/1000000;
     s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 2750365a7e..965a757772 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -349,14 +349,14 @@ void qemu_file_skip(QEMUFile *f, int size)
 }
 
 /*
- * Read 'size' bytes from file (at 'offset') into buf without moving the
- * pointer.
+ * Read 'size' bytes from file (at 'offset') without moving the
+ * pointer and set 'buf' to point to that data.
  *
  * It will return size bytes unless there was an error, in which case it will
  * return as many as it managed to read (assuming blocking fd's which
  * all current QEMUFile are)
  */
-int qemu_peek_buffer(QEMUFile *f, uint8_t *buf, int size, size_t offset)
+int qemu_peek_buffer(QEMUFile *f, uint8_t **buf, int size, size_t offset)
 {
     int pending;
     int index;
@@ -392,7 +392,7 @@ int qemu_peek_buffer(QEMUFile *f, uint8_t *buf, int size, size_t offset)
         size = pending;
     }
 
-    memcpy(buf, f->buf + index, size);
+    *buf = f->buf + index;
     return size;
 }
 
@@ -411,11 +411,13 @@ int qemu_get_buffer(QEMUFile *f, uint8_t *buf, int size)
 
     while (pending > 0) {
         int res;
+        uint8_t *src;
 
-        res = qemu_peek_buffer(f, buf, MIN(pending, IO_BUF_SIZE), 0);
+        res = qemu_peek_buffer(f, &src, MIN(pending, IO_BUF_SIZE), 0);
         if (res == 0) {
             return done;
         }
+        memcpy(buf, src, res);
         qemu_file_skip(f, res);
         buf += res;
         pending -= res;
@@ -585,3 +587,20 @@ int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src)
     }
     return len;
 }
+
+/*
+ * Get a string whose length is determined by a single preceding byte
+ * A preallocated 256 byte buffer must be passed in.
+ * Returns: len on success and a 0 terminated string in the buffer
+ *          else 0
+ *          (Note a 0 length string will return 0 either way)
+ */
+size_t qemu_get_counted_string(QEMUFile *f, char buf[256])
+{
+    size_t len = qemu_get_byte(f);
+    size_t res = qemu_get_buffer(f, (uint8_t *)buf, len);
+
+    buf[res] = 0;
+
+    return res == len ? res : 0;
+}
diff --git a/migration/ram.c b/migration/ram.c
new file mode 100644
index 0000000000..57368e1575
--- /dev/null
+++ b/migration/ram.c
@@ -0,0 +1,1628 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (c) 2011-2015 Red Hat Inc
+ *
+ * Authors:
+ *  Juan Quintela <quintela@redhat.com>
+ *
+ * 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 <zlib.h>
+#include "qemu/bitops.h"
+#include "qemu/bitmap.h"
+#include "qemu/timer.h"
+#include "qemu/main-loop.h"
+#include "migration/migration.h"
+#include "exec/address-spaces.h"
+#include "migration/page_cache.h"
+#include "qemu/error-report.h"
+#include "trace.h"
+#include "exec/ram_addr.h"
+#include "qemu/rcu_queue.h"
+
+#ifdef DEBUG_MIGRATION_RAM
+#define DPRINTF(fmt, ...) \
+    do { fprintf(stdout, "migration_ram: " fmt, ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) \
+    do { } while (0)
+#endif
+
+static bool mig_throttle_on;
+static int dirty_rate_high_cnt;
+static void check_guest_throttling(void);
+
+static uint64_t bitmap_sync_count;
+
+/***********************************************************/
+/* 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
+/* 0x80 is reserved in migration.h start with 0x100 next */
+#define RAM_SAVE_FLAG_COMPRESS_PAGE    0x100
+
+static const uint8_t ZERO_TARGET_PAGE[TARGET_PAGE_SIZE];
+
+static inline bool is_zero_range(uint8_t *p, uint64_t size)
+{
+    return buffer_find_nonzero_offset(p, size) == size;
+}
+
+/* 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;
+    /* Cache for XBZRLE, Protected by lock. */
+    PageCache *cache;
+    QemuMutex lock;
+} XBZRLE;
+
+/* buffer used for XBZRLE decoding */
+static uint8_t *xbzrle_decoded_buf;
+
+static void XBZRLE_cache_lock(void)
+{
+    if (migrate_use_xbzrle())
+        qemu_mutex_lock(&XBZRLE.lock);
+}
+
+static void XBZRLE_cache_unlock(void)
+{
+    if (migrate_use_xbzrle())
+        qemu_mutex_unlock(&XBZRLE.lock);
+}
+
+/*
+ * called from qmp_migrate_set_cache_size in main thread, possibly while
+ * a migration is in progress.
+ * A running migration maybe using the cache and might finish during this
+ * call, hence changes to the cache are protected by XBZRLE.lock().
+ */
+int64_t xbzrle_cache_resize(int64_t new_size)
+{
+    PageCache *new_cache;
+    int64_t ret;
+
+    if (new_size < TARGET_PAGE_SIZE) {
+        return -1;
+    }
+
+    XBZRLE_cache_lock();
+
+    if (XBZRLE.cache != NULL) {
+        if (pow2floor(new_size) == migrate_xbzrle_cache_size()) {
+            goto out_new_size;
+        }
+        new_cache = cache_init(new_size / TARGET_PAGE_SIZE,
+                                        TARGET_PAGE_SIZE);
+        if (!new_cache) {
+            error_report("Error creating cache");
+            ret = -1;
+            goto out;
+        }
+
+        cache_fini(XBZRLE.cache);
+        XBZRLE.cache = new_cache;
+    }
+
+out_new_size:
+    ret = pow2floor(new_size);
+out:
+    XBZRLE_cache_unlock();
+    return ret;
+}
+
+/* accounting for migration statistics */
+typedef struct AccountingInfo {
+    uint64_t dup_pages;
+    uint64_t skipped_pages;
+    uint64_t norm_pages;
+    uint64_t iterations;
+    uint64_t xbzrle_bytes;
+    uint64_t xbzrle_pages;
+    uint64_t xbzrle_cache_miss;
+    double xbzrle_cache_miss_rate;
+    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 skipped_mig_bytes_transferred(void)
+{
+    return acct_info.skipped_pages * TARGET_PAGE_SIZE;
+}
+
+uint64_t skipped_mig_pages_transferred(void)
+{
+    return acct_info.skipped_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;
+}
+
+double xbzrle_mig_cache_miss_rate(void)
+{
+    return acct_info.xbzrle_cache_miss_rate;
+}
+
+uint64_t xbzrle_mig_pages_overflow(void)
+{
+    return acct_info.xbzrle_overflows;
+}
+
+/* This is the last block that we have visited serching for dirty pages
+ */
+static RAMBlock *last_seen_block;
+/* This is the last block from where we have sent data */
+static RAMBlock *last_sent_block;
+static ram_addr_t last_offset;
+static unsigned long *migration_bitmap;
+static uint64_t migration_dirty_pages;
+static uint32_t last_version;
+static bool ram_bulk_stage;
+
+struct CompressParam {
+    bool start;
+    bool done;
+    QEMUFile *file;
+    QemuMutex mutex;
+    QemuCond cond;
+    RAMBlock *block;
+    ram_addr_t offset;
+};
+typedef struct CompressParam CompressParam;
+
+struct DecompressParam {
+    bool start;
+    QemuMutex mutex;
+    QemuCond cond;
+    void *des;
+    uint8 *compbuf;
+    int len;
+};
+typedef struct DecompressParam DecompressParam;
+
+static CompressParam *comp_param;
+static QemuThread *compress_threads;
+/* comp_done_cond is used to wake up the migration thread when
+ * one of the compression threads has finished the compression.
+ * comp_done_lock is used to co-work with comp_done_cond.
+ */
+static QemuMutex *comp_done_lock;
+static QemuCond *comp_done_cond;
+/* The empty QEMUFileOps will be used by file in CompressParam */
+static const QEMUFileOps empty_ops = { };
+
+static bool compression_switch;
+static bool quit_comp_thread;
+static bool quit_decomp_thread;
+static DecompressParam *decomp_param;
+static QemuThread *decompress_threads;
+static uint8_t *compressed_data_buf;
+
+static int do_compress_ram_page(CompressParam *param);
+
+static void *do_data_compress(void *opaque)
+{
+    CompressParam *param = opaque;
+
+    while (!quit_comp_thread) {
+        qemu_mutex_lock(&param->mutex);
+        /* Re-check the quit_comp_thread in case of
+         * terminate_compression_threads is called just before
+         * qemu_mutex_lock(&param->mutex) and after
+         * while(!quit_comp_thread), re-check it here can make
+         * sure the compression thread terminate as expected.
+         */
+        while (!param->start && !quit_comp_thread) {
+            qemu_cond_wait(&param->cond, &param->mutex);
+        }
+        if (!quit_comp_thread) {
+            do_compress_ram_page(param);
+        }
+        param->start = false;
+        qemu_mutex_unlock(&param->mutex);
+
+        qemu_mutex_lock(comp_done_lock);
+        param->done = true;
+        qemu_cond_signal(comp_done_cond);
+        qemu_mutex_unlock(comp_done_lock);
+    }
+
+    return NULL;
+}
+
+static inline void terminate_compression_threads(void)
+{
+    int idx, thread_count;
+
+    thread_count = migrate_compress_threads();
+    quit_comp_thread = true;
+    for (idx = 0; idx < thread_count; idx++) {
+        qemu_mutex_lock(&comp_param[idx].mutex);
+        qemu_cond_signal(&comp_param[idx].cond);
+        qemu_mutex_unlock(&comp_param[idx].mutex);
+    }
+}
+
+void migrate_compress_threads_join(void)
+{
+    int i, thread_count;
+
+    if (!migrate_use_compression()) {
+        return;
+    }
+    terminate_compression_threads();
+    thread_count = migrate_compress_threads();
+    for (i = 0; i < thread_count; i++) {
+        qemu_thread_join(compress_threads + i);
+        qemu_fclose(comp_param[i].file);
+        qemu_mutex_destroy(&comp_param[i].mutex);
+        qemu_cond_destroy(&comp_param[i].cond);
+    }
+    qemu_mutex_destroy(comp_done_lock);
+    qemu_cond_destroy(comp_done_cond);
+    g_free(compress_threads);
+    g_free(comp_param);
+    g_free(comp_done_cond);
+    g_free(comp_done_lock);
+    compress_threads = NULL;
+    comp_param = NULL;
+    comp_done_cond = NULL;
+    comp_done_lock = NULL;
+}
+
+void migrate_compress_threads_create(void)
+{
+    int i, thread_count;
+
+    if (!migrate_use_compression()) {
+        return;
+    }
+    quit_comp_thread = false;
+    compression_switch = true;
+    thread_count = migrate_compress_threads();
+    compress_threads = g_new0(QemuThread, thread_count);
+    comp_param = g_new0(CompressParam, thread_count);
+    comp_done_cond = g_new0(QemuCond, 1);
+    comp_done_lock = g_new0(QemuMutex, 1);
+    qemu_cond_init(comp_done_cond);
+    qemu_mutex_init(comp_done_lock);
+    for (i = 0; i < thread_count; i++) {
+        /* com_param[i].file is just used as a dummy buffer to save data, set
+         * it's ops to empty.
+         */
+        comp_param[i].file = qemu_fopen_ops(NULL, &empty_ops);
+        comp_param[i].done = true;
+        qemu_mutex_init(&comp_param[i].mutex);
+        qemu_cond_init(&comp_param[i].cond);
+        qemu_thread_create(compress_threads + i, "compress",
+                           do_data_compress, comp_param + i,
+                           QEMU_THREAD_JOINABLE);
+    }
+}
+
+/**
+ * save_page_header: Write page header to wire
+ *
+ * If this is the 1st block, it also writes the block identification
+ *
+ * Returns: Number of bytes written
+ *
+ * @f: QEMUFile where to send the data
+ * @block: block that contains the page we want to send
+ * @offset: offset inside the block for the page
+ *          in the lower bits, it contains flags
+ */
+static size_t save_page_header(QEMUFile *f, RAMBlock *block, ram_addr_t offset)
+{
+    size_t size;
+
+    qemu_put_be64(f, offset);
+    size = 8;
+
+    if (!(offset & RAM_SAVE_FLAG_CONTINUE)) {
+        qemu_put_byte(f, strlen(block->idstr));
+        qemu_put_buffer(f, (uint8_t *)block->idstr,
+                        strlen(block->idstr));
+        size += 1 + strlen(block->idstr);
+    }
+    return size;
+}
+
+/* Update the xbzrle cache to reflect a page that's been sent as all 0.
+ * The important thing is that a stale (not-yet-0'd) page be replaced
+ * by the new data.
+ * As a bonus, if the page wasn't in the cache it gets added so that
+ * when a small write is made into the 0'd page it gets XBZRLE sent
+ */
+static void xbzrle_cache_zero_page(ram_addr_t current_addr)
+{
+    if (ram_bulk_stage || !migrate_use_xbzrle()) {
+        return;
+    }
+
+    /* We don't care if this fails to allocate a new cache page
+     * as long as it updated an old one */
+    cache_insert(XBZRLE.cache, current_addr, ZERO_TARGET_PAGE,
+                 bitmap_sync_count);
+}
+
+#define ENCODING_FLAG_XBZRLE 0x1
+
+/**
+ * save_xbzrle_page: compress and send current page
+ *
+ * Returns: 1 means that we wrote the page
+ *          0 means that page is identical to the one already sent
+ *          -1 means that xbzrle would be longer than normal
+ *
+ * @f: QEMUFile where to send the data
+ * @current_data:
+ * @current_addr:
+ * @block: block that contains the page we want to send
+ * @offset: offset inside the block for the page
+ * @last_stage: if we are at the completion stage
+ * @bytes_transferred: increase it with the number of transferred bytes
+ */
+static int save_xbzrle_page(QEMUFile *f, uint8_t **current_data,
+                            ram_addr_t current_addr, RAMBlock *block,
+                            ram_addr_t offset, bool last_stage,
+                            uint64_t *bytes_transferred)
+{
+    int encoded_len = 0, bytes_xbzrle;
+    uint8_t *prev_cached_page;
+
+    if (!cache_is_cached(XBZRLE.cache, current_addr, bitmap_sync_count)) {
+        acct_info.xbzrle_cache_miss++;
+        if (!last_stage) {
+            if (cache_insert(XBZRLE.cache, current_addr, *current_data,
+                             bitmap_sync_count) == -1) {
+                return -1;
+            } else {
+                /* update *current_data when the page has been
+                   inserted into cache */
+                *current_data = get_cached_data(XBZRLE.cache, current_addr);
+            }
+        }
+        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 */
+        if (!last_stage) {
+            memcpy(prev_cached_page, *current_data, TARGET_PAGE_SIZE);
+            *current_data = prev_cached_page;
+        }
+        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 */
+    bytes_xbzrle = save_page_header(f, block, offset | 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_xbzrle += encoded_len + 1 + 2;
+    acct_info.xbzrle_pages++;
+    acct_info.xbzrle_bytes += bytes_xbzrle;
+    *bytes_transferred += bytes_xbzrle;
+
+    return 1;
+}
+
+static inline
+ram_addr_t migration_bitmap_find_and_reset_dirty(MemoryRegion *mr,
+                                                 ram_addr_t start)
+{
+    unsigned long base = mr->ram_addr >> TARGET_PAGE_BITS;
+    unsigned long nr = base + (start >> TARGET_PAGE_BITS);
+    uint64_t mr_size = TARGET_PAGE_ALIGN(memory_region_size(mr));
+    unsigned long size = base + (mr_size >> TARGET_PAGE_BITS);
+
+    unsigned long next;
+
+    if (ram_bulk_stage && nr > base) {
+        next = nr + 1;
+    } else {
+        next = find_next_bit(migration_bitmap, size, nr);
+    }
+
+    if (next < size) {
+        clear_bit(next, migration_bitmap);
+        migration_dirty_pages--;
+    }
+    return (next - base) << TARGET_PAGE_BITS;
+}
+
+static void migration_bitmap_sync_range(ram_addr_t start, ram_addr_t length)
+{
+    migration_dirty_pages +=
+        cpu_physical_memory_sync_dirty_bitmap(migration_bitmap, start, length);
+}
+
+
+/* Fix me: there are too many global variables used in migration process. */
+static int64_t start_time;
+static int64_t bytes_xfer_prev;
+static int64_t num_dirty_pages_period;
+static uint64_t xbzrle_cache_miss_prev;
+static uint64_t iterations_prev;
+
+static void migration_bitmap_sync_init(void)
+{
+    start_time = 0;
+    bytes_xfer_prev = 0;
+    num_dirty_pages_period = 0;
+    xbzrle_cache_miss_prev = 0;
+    iterations_prev = 0;
+}
+
+/* Called with iothread lock held, to protect ram_list.dirty_memory[] */
+static void migration_bitmap_sync(void)
+{
+    RAMBlock *block;
+    uint64_t num_dirty_pages_init = migration_dirty_pages;
+    MigrationState *s = migrate_get_current();
+    int64_t end_time;
+    int64_t bytes_xfer_now;
+
+    bitmap_sync_count++;
+
+    if (!bytes_xfer_prev) {
+        bytes_xfer_prev = ram_bytes_transferred();
+    }
+
+    if (!start_time) {
+        start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+    }
+
+    trace_migration_bitmap_sync_start();
+    address_space_sync_dirty_bitmap(&address_space_memory);
+
+    rcu_read_lock();
+    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+        migration_bitmap_sync_range(block->mr->ram_addr, block->used_length);
+    }
+    rcu_read_unlock();
+
+    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_clock_get_ms(QEMU_CLOCK_REALTIME);
+
+    /* more than 1 second = 1000 millisecons */
+    if (end_time > start_time + 1000) {
+        if (migrate_auto_converge()) {
+            /* The following detection logic can be refined later. For now:
+               Check to see if the dirtied bytes is 50% more than the approx.
+               amount of bytes that just got transferred since the last time we
+               were in this routine. If that happens >N times (for now N==4)
+               we turn on the throttle down logic */
+            bytes_xfer_now = ram_bytes_transferred();
+            if (s->dirty_pages_rate &&
+               (num_dirty_pages_period * TARGET_PAGE_SIZE >
+                   (bytes_xfer_now - bytes_xfer_prev)/2) &&
+               (dirty_rate_high_cnt++ > 4)) {
+                    trace_migration_throttle();
+                    mig_throttle_on = true;
+                    dirty_rate_high_cnt = 0;
+             }
+             bytes_xfer_prev = bytes_xfer_now;
+        } else {
+             mig_throttle_on = false;
+        }
+        if (migrate_use_xbzrle()) {
+            if (iterations_prev != acct_info.iterations) {
+                acct_info.xbzrle_cache_miss_rate =
+                   (double)(acct_info.xbzrle_cache_miss -
+                            xbzrle_cache_miss_prev) /
+                   (acct_info.iterations - iterations_prev);
+            }
+            iterations_prev = acct_info.iterations;
+            xbzrle_cache_miss_prev = acct_info.xbzrle_cache_miss;
+        }
+        s->dirty_pages_rate = num_dirty_pages_period * 1000
+            / (end_time - start_time);
+        s->dirty_bytes_rate = s->dirty_pages_rate * TARGET_PAGE_SIZE;
+        start_time = end_time;
+        num_dirty_pages_period = 0;
+    }
+    s->dirty_sync_count = bitmap_sync_count;
+}
+
+/**
+ * save_zero_page: Send the zero page to the stream
+ *
+ * Returns: Number of pages written.
+ *
+ * @f: QEMUFile where to send the data
+ * @block: block that contains the page we want to send
+ * @offset: offset inside the block for the page
+ * @p: pointer to the page
+ * @bytes_transferred: increase it with the number of transferred bytes
+ */
+static int save_zero_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
+                          uint8_t *p, uint64_t *bytes_transferred)
+{
+    int pages = -1;
+
+    if (is_zero_range(p, TARGET_PAGE_SIZE)) {
+        acct_info.dup_pages++;
+        *bytes_transferred += save_page_header(f, block,
+                                               offset | RAM_SAVE_FLAG_COMPRESS);
+        qemu_put_byte(f, 0);
+        *bytes_transferred += 1;
+        pages = 1;
+    }
+
+    return pages;
+}
+
+/**
+ * ram_save_page: Send the given page to the stream
+ *
+ * Returns: Number of pages written.
+ *
+ * @f: QEMUFile where to send the data
+ * @block: block that contains the page we want to send
+ * @offset: offset inside the block for the page
+ * @last_stage: if we are at the completion stage
+ * @bytes_transferred: increase it with the number of transferred bytes
+ */
+static int ram_save_page(QEMUFile *f, RAMBlock* block, ram_addr_t offset,
+                         bool last_stage, uint64_t *bytes_transferred)
+{
+    int pages = -1;
+    uint64_t bytes_xmit;
+    ram_addr_t current_addr;
+    MemoryRegion *mr = block->mr;
+    uint8_t *p;
+    int ret;
+    bool send_async = true;
+
+    p = memory_region_get_ram_ptr(mr) + offset;
+
+    /* In doubt sent page as normal */
+    bytes_xmit = 0;
+    ret = ram_control_save_page(f, block->offset,
+                           offset, TARGET_PAGE_SIZE, &bytes_xmit);
+    if (bytes_xmit) {
+        *bytes_transferred += bytes_xmit;
+        pages = 1;
+    }
+
+    XBZRLE_cache_lock();
+
+    current_addr = block->offset + offset;
+
+    if (block == last_sent_block) {
+        offset |= RAM_SAVE_FLAG_CONTINUE;
+    }
+    if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
+        if (ret != RAM_SAVE_CONTROL_DELAYED) {
+            if (bytes_xmit > 0) {
+                acct_info.norm_pages++;
+            } else if (bytes_xmit == 0) {
+                acct_info.dup_pages++;
+            }
+        }
+    } else {
+        pages = save_zero_page(f, block, offset, p, bytes_transferred);
+        if (pages > 0) {
+            /* Must let xbzrle know, otherwise a previous (now 0'd) cached
+             * page would be stale
+             */
+            xbzrle_cache_zero_page(current_addr);
+        } else if (!ram_bulk_stage && migrate_use_xbzrle()) {
+            pages = save_xbzrle_page(f, &p, current_addr, block,
+                                     offset, last_stage, bytes_transferred);
+            if (!last_stage) {
+                /* Can't send this cached data async, since the cache page
+                 * might get updated before it gets to the wire
+                 */
+                send_async = false;
+            }
+        }
+    }
+
+    /* XBZRLE overflow or normal page */
+    if (pages == -1) {
+        *bytes_transferred += save_page_header(f, block,
+                                               offset | RAM_SAVE_FLAG_PAGE);
+        if (send_async) {
+            qemu_put_buffer_async(f, p, TARGET_PAGE_SIZE);
+        } else {
+            qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
+        }
+        *bytes_transferred += TARGET_PAGE_SIZE;
+        pages = 1;
+        acct_info.norm_pages++;
+    }
+
+    XBZRLE_cache_unlock();
+
+    return pages;
+}
+
+static int do_compress_ram_page(CompressParam *param)
+{
+    int bytes_sent, blen;
+    uint8_t *p;
+    RAMBlock *block = param->block;
+    ram_addr_t offset = param->offset;
+
+    p = memory_region_get_ram_ptr(block->mr) + (offset & TARGET_PAGE_MASK);
+
+    bytes_sent = save_page_header(param->file, block, offset |
+                                  RAM_SAVE_FLAG_COMPRESS_PAGE);
+    blen = qemu_put_compression_data(param->file, p, TARGET_PAGE_SIZE,
+                                     migrate_compress_level());
+    bytes_sent += blen;
+
+    return bytes_sent;
+}
+
+static inline void start_compression(CompressParam *param)
+{
+    param->done = false;
+    qemu_mutex_lock(&param->mutex);
+    param->start = true;
+    qemu_cond_signal(&param->cond);
+    qemu_mutex_unlock(&param->mutex);
+}
+
+static inline void start_decompression(DecompressParam *param)
+{
+    qemu_mutex_lock(&param->mutex);
+    param->start = true;
+    qemu_cond_signal(&param->cond);
+    qemu_mutex_unlock(&param->mutex);
+}
+
+static uint64_t bytes_transferred;
+
+static void flush_compressed_data(QEMUFile *f)
+{
+    int idx, len, thread_count;
+
+    if (!migrate_use_compression()) {
+        return;
+    }
+    thread_count = migrate_compress_threads();
+    for (idx = 0; idx < thread_count; idx++) {
+        if (!comp_param[idx].done) {
+            qemu_mutex_lock(comp_done_lock);
+            while (!comp_param[idx].done && !quit_comp_thread) {
+                qemu_cond_wait(comp_done_cond, comp_done_lock);
+            }
+            qemu_mutex_unlock(comp_done_lock);
+        }
+        if (!quit_comp_thread) {
+            len = qemu_put_qemu_file(f, comp_param[idx].file);
+            bytes_transferred += len;
+        }
+    }
+}
+
+static inline void set_compress_params(CompressParam *param, RAMBlock *block,
+                                       ram_addr_t offset)
+{
+    param->block = block;
+    param->offset = offset;
+}
+
+static int compress_page_with_multi_thread(QEMUFile *f, RAMBlock *block,
+                                           ram_addr_t offset,
+                                           uint64_t *bytes_transferred)
+{
+    int idx, thread_count, bytes_xmit = -1, pages = -1;
+
+    thread_count = migrate_compress_threads();
+    qemu_mutex_lock(comp_done_lock);
+    while (true) {
+        for (idx = 0; idx < thread_count; idx++) {
+            if (comp_param[idx].done) {
+                bytes_xmit = qemu_put_qemu_file(f, comp_param[idx].file);
+                set_compress_params(&comp_param[idx], block, offset);
+                start_compression(&comp_param[idx]);
+                pages = 1;
+                acct_info.norm_pages++;
+                *bytes_transferred += bytes_xmit;
+                break;
+            }
+        }
+        if (pages > 0) {
+            break;
+        } else {
+            qemu_cond_wait(comp_done_cond, comp_done_lock);
+        }
+    }
+    qemu_mutex_unlock(comp_done_lock);
+
+    return pages;
+}
+
+/**
+ * ram_save_compressed_page: compress the given page and send it to the stream
+ *
+ * Returns: Number of pages written.
+ *
+ * @f: QEMUFile where to send the data
+ * @block: block that contains the page we want to send
+ * @offset: offset inside the block for the page
+ * @last_stage: if we are at the completion stage
+ * @bytes_transferred: increase it with the number of transferred bytes
+ */
+static int ram_save_compressed_page(QEMUFile *f, RAMBlock *block,
+                                    ram_addr_t offset, bool last_stage,
+                                    uint64_t *bytes_transferred)
+{
+    int pages = -1;
+    uint64_t bytes_xmit;
+    MemoryRegion *mr = block->mr;
+    uint8_t *p;
+    int ret;
+
+    p = memory_region_get_ram_ptr(mr) + offset;
+
+    bytes_xmit = 0;
+    ret = ram_control_save_page(f, block->offset,
+                                offset, TARGET_PAGE_SIZE, &bytes_xmit);
+    if (bytes_xmit) {
+        *bytes_transferred += bytes_xmit;
+        pages = 1;
+    }
+    if (block == last_sent_block) {
+        offset |= RAM_SAVE_FLAG_CONTINUE;
+    }
+    if (ret != RAM_SAVE_CONTROL_NOT_SUPP) {
+        if (ret != RAM_SAVE_CONTROL_DELAYED) {
+            if (bytes_xmit > 0) {
+                acct_info.norm_pages++;
+            } else if (bytes_xmit == 0) {
+                acct_info.dup_pages++;
+            }
+        }
+    } else {
+        /* When starting the process of a new block, the first page of
+         * the block should be sent out before other pages in the same
+         * block, and all the pages in last block should have been sent
+         * out, keeping this order is important, because the 'cont' flag
+         * is used to avoid resending the block name.
+         */
+        if (block != last_sent_block) {
+            flush_compressed_data(f);
+            pages = save_zero_page(f, block, offset, p, bytes_transferred);
+            if (pages == -1) {
+                set_compress_params(&comp_param[0], block, offset);
+                /* Use the qemu thread to compress the data to make sure the
+                 * first page is sent out before other pages
+                 */
+                bytes_xmit = do_compress_ram_page(&comp_param[0]);
+                acct_info.norm_pages++;
+                qemu_put_qemu_file(f, comp_param[0].file);
+                *bytes_transferred += bytes_xmit;
+                pages = 1;
+            }
+        } else {
+            pages = save_zero_page(f, block, offset, p, bytes_transferred);
+            if (pages == -1) {
+                pages = compress_page_with_multi_thread(f, block, offset,
+                                                        bytes_transferred);
+            }
+        }
+    }
+
+    return pages;
+}
+
+/**
+ * ram_find_and_save_block: Finds a dirty page and sends it to f
+ *
+ * Called within an RCU critical section.
+ *
+ * Returns:  The number of pages written
+ *           0 means no dirty pages
+ *
+ * @f: QEMUFile where to send the data
+ * @last_stage: if we are at the completion stage
+ * @bytes_transferred: increase it with the number of transferred bytes
+ */
+
+static int ram_find_and_save_block(QEMUFile *f, bool last_stage,
+                                   uint64_t *bytes_transferred)
+{
+    RAMBlock *block = last_seen_block;
+    ram_addr_t offset = last_offset;
+    bool complete_round = false;
+    int pages = 0;
+    MemoryRegion *mr;
+
+    if (!block)
+        block = QLIST_FIRST_RCU(&ram_list.blocks);
+
+    while (true) {
+        mr = block->mr;
+        offset = migration_bitmap_find_and_reset_dirty(mr, offset);
+        if (complete_round && block == last_seen_block &&
+            offset >= last_offset) {
+            break;
+        }
+        if (offset >= block->used_length) {
+            offset = 0;
+            block = QLIST_NEXT_RCU(block, next);
+            if (!block) {
+                block = QLIST_FIRST_RCU(&ram_list.blocks);
+                complete_round = true;
+                ram_bulk_stage = false;
+                if (migrate_use_xbzrle()) {
+                    /* If xbzrle is on, stop using the data compression at this
+                     * point. In theory, xbzrle can do better than compression.
+                     */
+                    flush_compressed_data(f);
+                    compression_switch = false;
+                }
+            }
+        } else {
+            if (compression_switch && migrate_use_compression()) {
+                pages = ram_save_compressed_page(f, block, offset, last_stage,
+                                                 bytes_transferred);
+            } else {
+                pages = ram_save_page(f, block, offset, last_stage,
+                                      bytes_transferred);
+            }
+
+            /* if page is unmodified, continue to the next */
+            if (pages > 0) {
+                last_sent_block = block;
+                break;
+            }
+        }
+    }
+
+    last_seen_block = block;
+    last_offset = offset;
+
+    return pages;
+}
+
+void acct_update_position(QEMUFile *f, size_t size, bool zero)
+{
+    uint64_t pages = size / TARGET_PAGE_SIZE;
+    if (zero) {
+        acct_info.dup_pages += pages;
+    } else {
+        acct_info.norm_pages += pages;
+        bytes_transferred += size;
+        qemu_update_position(f, size);
+    }
+}
+
+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;
+
+    rcu_read_lock();
+    QLIST_FOREACH_RCU(block, &ram_list.blocks, next)
+        total += block->used_length;
+    rcu_read_unlock();
+    return total;
+}
+
+void free_xbzrle_decoded_buf(void)
+{
+    g_free(xbzrle_decoded_buf);
+    xbzrle_decoded_buf = NULL;
+}
+
+static void migration_end(void)
+{
+    if (migration_bitmap) {
+        memory_global_dirty_log_stop();
+        g_free(migration_bitmap);
+        migration_bitmap = NULL;
+    }
+
+    XBZRLE_cache_lock();
+    if (XBZRLE.cache) {
+        cache_fini(XBZRLE.cache);
+        g_free(XBZRLE.encoded_buf);
+        g_free(XBZRLE.current_buf);
+        XBZRLE.cache = NULL;
+        XBZRLE.encoded_buf = NULL;
+        XBZRLE.current_buf = NULL;
+    }
+    XBZRLE_cache_unlock();
+}
+
+static void ram_migration_cancel(void *opaque)
+{
+    migration_end();
+}
+
+static void reset_ram_globals(void)
+{
+    last_seen_block = NULL;
+    last_sent_block = NULL;
+    last_offset = 0;
+    last_version = ram_list.version;
+    ram_bulk_stage = true;
+}
+
+#define MAX_WAIT 50 /* ms, half buffered_file limit */
+
+
+/* Each of ram_save_setup, ram_save_iterate and ram_save_complete has
+ * long-running RCU critical section.  When rcu-reclaims in the code
+ * start to become numerous it will be necessary to reduce the
+ * granularity of these critical sections.
+ */
+
+static int ram_save_setup(QEMUFile *f, void *opaque)
+{
+    RAMBlock *block;
+    int64_t ram_bitmap_pages; /* Size of bitmap in pages, including gaps */
+
+    mig_throttle_on = false;
+    dirty_rate_high_cnt = 0;
+    bitmap_sync_count = 0;
+    migration_bitmap_sync_init();
+
+    if (migrate_use_xbzrle()) {
+        XBZRLE_cache_lock();
+        XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
+                                  TARGET_PAGE_SIZE,
+                                  TARGET_PAGE_SIZE);
+        if (!XBZRLE.cache) {
+            XBZRLE_cache_unlock();
+            error_report("Error creating cache");
+            return -1;
+        }
+        XBZRLE_cache_unlock();
+
+        /* We prefer not to abort if there is no memory */
+        XBZRLE.encoded_buf = g_try_malloc0(TARGET_PAGE_SIZE);
+        if (!XBZRLE.encoded_buf) {
+            error_report("Error allocating encoded_buf");
+            return -1;
+        }
+
+        XBZRLE.current_buf = g_try_malloc(TARGET_PAGE_SIZE);
+        if (!XBZRLE.current_buf) {
+            error_report("Error allocating current_buf");
+            g_free(XBZRLE.encoded_buf);
+            XBZRLE.encoded_buf = NULL;
+            return -1;
+        }
+
+        acct_clear();
+    }
+
+    /* iothread lock needed for ram_list.dirty_memory[] */
+    qemu_mutex_lock_iothread();
+    qemu_mutex_lock_ramlist();
+    rcu_read_lock();
+    bytes_transferred = 0;
+    reset_ram_globals();
+
+    ram_bitmap_pages = last_ram_offset() >> TARGET_PAGE_BITS;
+    migration_bitmap = bitmap_new(ram_bitmap_pages);
+    bitmap_set(migration_bitmap, 0, ram_bitmap_pages);
+
+    /*
+     * Count the total number of pages used by ram blocks not including any
+     * gaps due to alignment or unplugs.
+     */
+    migration_dirty_pages = ram_bytes_total() >> TARGET_PAGE_BITS;
+
+    memory_global_dirty_log_start();
+    migration_bitmap_sync();
+    qemu_mutex_unlock_ramlist();
+    qemu_mutex_unlock_iothread();
+
+    qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
+
+    QLIST_FOREACH_RCU(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->used_length);
+    }
+
+    rcu_read_unlock();
+
+    ram_control_before_iterate(f, RAM_CONTROL_SETUP);
+    ram_control_after_iterate(f, RAM_CONTROL_SETUP);
+
+    qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
+
+    return 0;
+}
+
+static int ram_save_iterate(QEMUFile *f, void *opaque)
+{
+    int ret;
+    int i;
+    int64_t t0;
+    int pages_sent = 0;
+
+    rcu_read_lock();
+    if (ram_list.version != last_version) {
+        reset_ram_globals();
+    }
+
+    /* Read version before ram_list.blocks */
+    smp_rmb();
+
+    ram_control_before_iterate(f, RAM_CONTROL_ROUND);
+
+    t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+    i = 0;
+    while ((ret = qemu_file_rate_limit(f)) == 0) {
+        int pages;
+
+        pages = ram_find_and_save_block(f, false, &bytes_transferred);
+        /* no more pages to sent */
+        if (pages == 0) {
+            break;
+        }
+        pages_sent += pages;
+        acct_info.iterations++;
+        check_guest_throttling();
+        /* 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_clock_get_ns(QEMU_CLOCK_REALTIME) - t0) / 1000000;
+            if (t1 > MAX_WAIT) {
+                DPRINTF("big wait: %" PRIu64 " milliseconds, %d iterations\n",
+                        t1, i);
+                break;
+            }
+        }
+        i++;
+    }
+    flush_compressed_data(f);
+    rcu_read_unlock();
+
+    /*
+     * Must occur before EOS (or any QEMUFile operation)
+     * because of RDMA protocol.
+     */
+    ram_control_after_iterate(f, RAM_CONTROL_ROUND);
+
+    qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
+    bytes_transferred += 8;
+
+    ret = qemu_file_get_error(f);
+    if (ret < 0) {
+        return ret;
+    }
+
+    return pages_sent;
+}
+
+/* Called with iothread lock */
+static int ram_save_complete(QEMUFile *f, void *opaque)
+{
+    rcu_read_lock();
+
+    migration_bitmap_sync();
+
+    ram_control_before_iterate(f, RAM_CONTROL_FINISH);
+
+    /* try transferring iterative blocks of memory */
+
+    /* flush all remaining blocks regardless of rate limiting */
+    while (true) {
+        int pages;
+
+        pages = ram_find_and_save_block(f, true, &bytes_transferred);
+        /* no more blocks to sent */
+        if (pages == 0) {
+            break;
+        }
+    }
+
+    flush_compressed_data(f);
+    ram_control_after_iterate(f, RAM_CONTROL_FINISH);
+    migration_end();
+
+    rcu_read_unlock();
+    qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
+
+    return 0;
+}
+
+static uint64_t ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
+{
+    uint64_t remaining_size;
+
+    remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
+
+    if (remaining_size < max_size) {
+        qemu_mutex_lock_iothread();
+        rcu_read_lock();
+        migration_bitmap_sync();
+        rcu_read_unlock();
+        qemu_mutex_unlock_iothread();
+        remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
+    }
+    return remaining_size;
+}
+
+static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
+{
+    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) {
+        error_report("Failed to load XBZRLE page - wrong compression!");
+        return -1;
+    }
+
+    if (xh_len > TARGET_PAGE_SIZE) {
+        error_report("Failed to load XBZRLE page - len overflow!");
+        return -1;
+    }
+    /* load data and decode */
+    qemu_get_buffer(f, xbzrle_decoded_buf, xh_len);
+
+    /* decode RLE */
+    if (xbzrle_decode_buffer(xbzrle_decoded_buf, xh_len, host,
+                             TARGET_PAGE_SIZE) == -1) {
+        error_report("Failed to load XBZRLE page - decode error!");
+        return -1;
+    }
+
+    return 0;
+}
+
+/* Must be called from within a rcu critical section.
+ * Returns a pointer from within the RCU-protected ram_list.
+ */
+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 || block->max_length <= offset) {
+            error_report("Ack, bad migration stream!");
+            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;
+
+    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+        if (!strncmp(id, block->idstr, sizeof(id)) &&
+            block->max_length > offset) {
+            return memory_region_get_ram_ptr(block->mr) + offset;
+        }
+    }
+
+    error_report("Can't find block %s!", id);
+    return NULL;
+}
+
+/*
+ * If a page (or a whole RDMA chunk) has been
+ * determined to be zero, then zap it.
+ */
+void ram_handle_compressed(void *host, uint8_t ch, uint64_t size)
+{
+    if (ch != 0 || !is_zero_range(host, size)) {
+        memset(host, ch, size);
+    }
+}
+
+static void *do_data_decompress(void *opaque)
+{
+    DecompressParam *param = opaque;
+    unsigned long pagesize;
+
+    while (!quit_decomp_thread) {
+        qemu_mutex_lock(&param->mutex);
+        while (!param->start && !quit_decomp_thread) {
+            qemu_cond_wait(&param->cond, &param->mutex);
+            pagesize = TARGET_PAGE_SIZE;
+            if (!quit_decomp_thread) {
+                /* uncompress() will return failed in some case, especially
+                 * when the page is dirted when doing the compression, it's
+                 * not a problem because the dirty page will be retransferred
+                 * and uncompress() won't break the data in other pages.
+                 */
+                uncompress((Bytef *)param->des, &pagesize,
+                           (const Bytef *)param->compbuf, param->len);
+            }
+            param->start = false;
+        }
+        qemu_mutex_unlock(&param->mutex);
+    }
+
+    return NULL;
+}
+
+void migrate_decompress_threads_create(void)
+{
+    int i, thread_count;
+
+    thread_count = migrate_decompress_threads();
+    decompress_threads = g_new0(QemuThread, thread_count);
+    decomp_param = g_new0(DecompressParam, thread_count);
+    compressed_data_buf = g_malloc0(compressBound(TARGET_PAGE_SIZE));
+    quit_decomp_thread = false;
+    for (i = 0; i < thread_count; i++) {
+        qemu_mutex_init(&decomp_param[i].mutex);
+        qemu_cond_init(&decomp_param[i].cond);
+        decomp_param[i].compbuf = g_malloc0(compressBound(TARGET_PAGE_SIZE));
+        qemu_thread_create(decompress_threads + i, "decompress",
+                           do_data_decompress, decomp_param + i,
+                           QEMU_THREAD_JOINABLE);
+    }
+}
+
+void migrate_decompress_threads_join(void)
+{
+    int i, thread_count;
+
+    quit_decomp_thread = true;
+    thread_count = migrate_decompress_threads();
+    for (i = 0; i < thread_count; i++) {
+        qemu_mutex_lock(&decomp_param[i].mutex);
+        qemu_cond_signal(&decomp_param[i].cond);
+        qemu_mutex_unlock(&decomp_param[i].mutex);
+    }
+    for (i = 0; i < thread_count; i++) {
+        qemu_thread_join(decompress_threads + i);
+        qemu_mutex_destroy(&decomp_param[i].mutex);
+        qemu_cond_destroy(&decomp_param[i].cond);
+        g_free(decomp_param[i].compbuf);
+    }
+    g_free(decompress_threads);
+    g_free(decomp_param);
+    g_free(compressed_data_buf);
+    decompress_threads = NULL;
+    decomp_param = NULL;
+    compressed_data_buf = NULL;
+}
+
+static void decompress_data_with_multi_threads(uint8_t *compbuf,
+                                               void *host, int len)
+{
+    int idx, thread_count;
+
+    thread_count = migrate_decompress_threads();
+    while (true) {
+        for (idx = 0; idx < thread_count; idx++) {
+            if (!decomp_param[idx].start) {
+                memcpy(decomp_param[idx].compbuf, compbuf, len);
+                decomp_param[idx].des = host;
+                decomp_param[idx].len = len;
+                start_decompression(&decomp_param[idx]);
+                break;
+            }
+        }
+        if (idx < thread_count) {
+            break;
+        }
+    }
+}
+
+static int ram_load(QEMUFile *f, void *opaque, int version_id)
+{
+    int flags = 0, ret = 0;
+    static uint64_t seq_iter;
+    int len = 0;
+
+    seq_iter++;
+
+    if (version_id != 4) {
+        ret = -EINVAL;
+    }
+
+    /* This RCU critical section can be very long running.
+     * When RCU reclaims in the code start to become numerous,
+     * it will be necessary to reduce the granularity of this
+     * critical section.
+     */
+    rcu_read_lock();
+    while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) {
+        ram_addr_t addr, total_ram_bytes;
+        void *host;
+        uint8_t ch;
+
+        addr = qemu_get_be64(f);
+        flags = addr & ~TARGET_PAGE_MASK;
+        addr &= TARGET_PAGE_MASK;
+
+        switch (flags & ~RAM_SAVE_FLAG_CONTINUE) {
+        case RAM_SAVE_FLAG_MEM_SIZE:
+            /* Synchronize RAM block list */
+            total_ram_bytes = addr;
+            while (!ret && total_ram_bytes) {
+                RAMBlock *block;
+                char id[256];
+                ram_addr_t length;
+
+                len = qemu_get_byte(f);
+                qemu_get_buffer(f, (uint8_t *)id, len);
+                id[len] = 0;
+                length = qemu_get_be64(f);
+
+                QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+                    if (!strncmp(id, block->idstr, sizeof(id))) {
+                        if (length != block->used_length) {
+                            Error *local_err = NULL;
+
+                            ret = qemu_ram_resize(block->offset, length, &local_err);
+                            if (local_err) {
+                                error_report_err(local_err);
+                            }
+                        }
+                        break;
+                    }
+                }
+
+                if (!block) {
+                    error_report("Unknown ramblock \"%s\", cannot "
+                                 "accept migration", id);
+                    ret = -EINVAL;
+                }
+
+                total_ram_bytes -= length;
+            }
+            break;
+        case RAM_SAVE_FLAG_COMPRESS:
+            host = host_from_stream_offset(f, addr, flags);
+            if (!host) {
+                error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
+                ret = -EINVAL;
+                break;
+            }
+            ch = qemu_get_byte(f);
+            ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);
+            break;
+        case RAM_SAVE_FLAG_PAGE:
+            host = host_from_stream_offset(f, addr, flags);
+            if (!host) {
+                error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
+                ret = -EINVAL;
+                break;
+            }
+            qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
+            break;
+        case RAM_SAVE_FLAG_COMPRESS_PAGE:
+            host = host_from_stream_offset(f, addr, flags);
+            if (!host) {
+                error_report("Invalid RAM offset " RAM_ADDR_FMT, addr);
+                ret = -EINVAL;
+                break;
+            }
+
+            len = qemu_get_be32(f);
+            if (len < 0 || len > compressBound(TARGET_PAGE_SIZE)) {
+                error_report("Invalid compressed data length: %d", len);
+                ret = -EINVAL;
+                break;
+            }
+            qemu_get_buffer(f, compressed_data_buf, len);
+            decompress_data_with_multi_threads(compressed_data_buf, host, len);
+            break;
+        case RAM_SAVE_FLAG_XBZRLE:
+            host = host_from_stream_offset(f, addr, flags);
+            if (!host) {
+                error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
+                ret = -EINVAL;
+                break;
+            }
+            if (load_xbzrle(f, addr, host) < 0) {
+                error_report("Failed to decompress XBZRLE page at "
+                             RAM_ADDR_FMT, addr);
+                ret = -EINVAL;
+                break;
+            }
+            break;
+        case RAM_SAVE_FLAG_EOS:
+            /* normal exit */
+            break;
+        default:
+            if (flags & RAM_SAVE_FLAG_HOOK) {
+                ram_control_load_hook(f, flags);
+            } else {
+                error_report("Unknown combination of migration flags: %#x",
+                             flags);
+                ret = -EINVAL;
+            }
+        }
+        if (!ret) {
+            ret = qemu_file_get_error(f);
+        }
+    }
+
+    rcu_read_unlock();
+    DPRINTF("Completed load of VM with exit code %d seq iteration "
+            "%" PRIu64 "\n", ret, seq_iter);
+    return ret;
+}
+
+static SaveVMHandlers savevm_ram_handlers = {
+    .save_live_setup = ram_save_setup,
+    .save_live_iterate = ram_save_iterate,
+    .save_live_complete = ram_save_complete,
+    .save_live_pending = ram_save_pending,
+    .load_state = ram_load,
+    .cancel = ram_migration_cancel,
+};
+
+void ram_mig_init(void)
+{
+    qemu_mutex_init(&XBZRLE.lock);
+    register_savevm_live(NULL, "ram", 0, 4, &savevm_ram_handlers, NULL);
+}
+/* Stub function that's gets run on the vcpu when its brought out of the
+   VM to run inside qemu via async_run_on_cpu()*/
+
+static void mig_sleep_cpu(void *opq)
+{
+    qemu_mutex_unlock_iothread();
+    g_usleep(30*1000);
+    qemu_mutex_lock_iothread();
+}
+
+/* To reduce the dirty rate explicitly disallow the VCPUs from spending
+   much time in the VM. The migration thread will try to catchup.
+   Workload will experience a performance drop.
+*/
+static void mig_throttle_guest_down(void)
+{
+    CPUState *cpu;
+
+    qemu_mutex_lock_iothread();
+    CPU_FOREACH(cpu) {
+        async_run_on_cpu(cpu, mig_sleep_cpu, NULL);
+    }
+    qemu_mutex_unlock_iothread();
+}
+
+static void check_guest_throttling(void)
+{
+    static int64_t t0;
+    int64_t        t1;
+
+    if (!mig_throttle_on) {
+        return;
+    }
+
+    if (!t0)  {
+        t0 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+        return;
+    }
+
+    t1 = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+
+    /* If it has been more than 40 ms since the last time the guest
+     * was throttled then do it again.
+     */
+    if (40 < (t1-t0)/1000000) {
+        mig_throttle_guest_down();
+        t0 = t1;
+    }
+}
diff --git a/migration/rdma.c b/migration/rdma.c
index 77e34441dc..48b3e64b34 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -236,13 +236,13 @@ typedef struct RDMALocalBlock {
  * corresponding RDMALocalBlock with
  * the information needed to perform the actual RDMA.
  */
-typedef struct QEMU_PACKED RDMARemoteBlock {
+typedef struct QEMU_PACKED RDMADestBlock {
     uint64_t remote_host_addr;
     uint64_t offset;
     uint64_t length;
     uint32_t remote_rkey;
     uint32_t padding;
-} RDMARemoteBlock;
+} RDMADestBlock;
 
 static uint64_t htonll(uint64_t v)
 {
@@ -258,20 +258,20 @@ static uint64_t ntohll(uint64_t v) {
     return ((uint64_t)ntohl(u.lv[0]) << 32) | (uint64_t) ntohl(u.lv[1]);
 }
 
-static void remote_block_to_network(RDMARemoteBlock *rb)
+static void dest_block_to_network(RDMADestBlock *db)
 {
-    rb->remote_host_addr = htonll(rb->remote_host_addr);
-    rb->offset = htonll(rb->offset);
-    rb->length = htonll(rb->length);
-    rb->remote_rkey = htonl(rb->remote_rkey);
+    db->remote_host_addr = htonll(db->remote_host_addr);
+    db->offset = htonll(db->offset);
+    db->length = htonll(db->length);
+    db->remote_rkey = htonl(db->remote_rkey);
 }
 
-static void network_to_remote_block(RDMARemoteBlock *rb)
+static void network_to_dest_block(RDMADestBlock *db)
 {
-    rb->remote_host_addr = ntohll(rb->remote_host_addr);
-    rb->offset = ntohll(rb->offset);
-    rb->length = ntohll(rb->length);
-    rb->remote_rkey = ntohl(rb->remote_rkey);
+    db->remote_host_addr = ntohll(db->remote_host_addr);
+    db->offset = ntohll(db->offset);
+    db->length = ntohll(db->length);
+    db->remote_rkey = ntohl(db->remote_rkey);
 }
 
 /*
@@ -350,7 +350,7 @@ typedef struct RDMAContext {
      * Description of ram blocks used throughout the code.
      */
     RDMALocalBlocks local_ram_blocks;
-    RDMARemoteBlock *block;
+    RDMADestBlock  *dest_blocks;
 
     /*
      * Migration on *destination* started.
@@ -570,10 +570,10 @@ static int rdma_add_block(RDMAContext *rdma, void *host_addr,
  * in advanced before the migration starts. This tells us where the RAM blocks
  * are so that we can register them individually.
  */
-static void qemu_rdma_init_one_block(void *host_addr,
+static int qemu_rdma_init_one_block(const char *block_name, void *host_addr,
     ram_addr_t block_offset, ram_addr_t length, void *opaque)
 {
-    rdma_add_block(opaque, host_addr, block_offset, length);
+    return rdma_add_block(opaque, host_addr, block_offset, length);
 }
 
 /*
@@ -590,7 +590,7 @@ static int qemu_rdma_init_ram_blocks(RDMAContext *rdma)
     memset(local, 0, sizeof *local);
     qemu_ram_foreach_block(qemu_rdma_init_one_block, rdma);
     trace_qemu_rdma_init_ram_blocks(local->nb_blocks);
-    rdma->block = (RDMARemoteBlock *) g_malloc0(sizeof(RDMARemoteBlock) *
+    rdma->dest_blocks = (RDMADestBlock *) g_malloc0(sizeof(RDMADestBlock) *
                         rdma->local_ram_blocks.nb_blocks);
     local->init = true;
     return 0;
@@ -790,6 +790,13 @@ static int qemu_rdma_broken_ipv6_kernel(Error **errp, struct ibv_context *verbs)
 
         for (x = 0; x < num_devices; x++) {
             verbs = ibv_open_device(dev_list[x]);
+            if (!verbs) {
+                if (errno == EPERM) {
+                    continue;
+                } else {
+                    return -EINVAL;
+                }
+            }
 
             if (ibv_query_port(verbs, 1, &port_attr)) {
                 ibv_close_device(verbs);
@@ -2177,8 +2184,8 @@ static void qemu_rdma_cleanup(RDMAContext *rdma)
         rdma->connected = false;
     }
 
-    g_free(rdma->block);
-    rdma->block = NULL;
+    g_free(rdma->dest_blocks);
+    rdma->dest_blocks = NULL;
 
     for (idx = 0; idx < RDMA_WRID_MAX; idx++) {
         if (rdma->wr_data[idx].control_mr) {
@@ -2445,7 +2452,6 @@ static void *qemu_rdma_data_init(const char *host_port, Error **errp)
 
     if (host_port) {
         rdma = g_malloc0(sizeof(RDMAContext));
-        memset(rdma, 0, sizeof(RDMAContext));
         rdma->current_index = -1;
         rdma->current_chunk = -1;
 
@@ -2967,25 +2973,25 @@ static int qemu_rdma_registration_handle(QEMUFile *f, void *opaque,
              * their "local" descriptions with what was sent.
              */
             for (i = 0; i < local->nb_blocks; i++) {
-                rdma->block[i].remote_host_addr =
+                rdma->dest_blocks[i].remote_host_addr =
                     (uintptr_t)(local->block[i].local_host_addr);
 
                 if (rdma->pin_all) {
-                    rdma->block[i].remote_rkey = local->block[i].mr->rkey;
+                    rdma->dest_blocks[i].remote_rkey = local->block[i].mr->rkey;
                 }
 
-                rdma->block[i].offset = local->block[i].offset;
-                rdma->block[i].length = local->block[i].length;
+                rdma->dest_blocks[i].offset = local->block[i].offset;
+                rdma->dest_blocks[i].length = local->block[i].length;
 
-                remote_block_to_network(&rdma->block[i]);
+                dest_block_to_network(&rdma->dest_blocks[i]);
             }
 
             blocks.len = rdma->local_ram_blocks.nb_blocks
-                                                * sizeof(RDMARemoteBlock);
+                                                * sizeof(RDMADestBlock);
 
 
             ret = qemu_rdma_post_send_control(rdma,
-                                        (uint8_t *) rdma->block, &blocks);
+                                        (uint8_t *) rdma->dest_blocks, &blocks);
 
             if (ret < 0) {
                 error_report("rdma migration: error sending remote info");
@@ -3141,7 +3147,7 @@ static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque,
     if (flags == RAM_CONTROL_SETUP) {
         RDMAControlHeader resp = {.type = RDMA_CONTROL_RAM_BLOCKS_RESULT };
         RDMALocalBlocks *local = &rdma->local_ram_blocks;
-        int reg_result_idx, i, j, nb_remote_blocks;
+        int reg_result_idx, i, j, nb_dest_blocks;
 
         head.type = RDMA_CONTROL_RAM_BLOCKS_REQUEST;
         trace_qemu_rdma_registration_stop_ram();
@@ -3162,7 +3168,7 @@ static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque,
             return ret;
         }
 
-        nb_remote_blocks = resp.len / sizeof(RDMARemoteBlock);
+        nb_dest_blocks = resp.len / sizeof(RDMADestBlock);
 
         /*
          * The protocol uses two different sets of rkeys (mutually exclusive):
@@ -3176,7 +3182,7 @@ static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque,
          * and then propagates the remote ram block descriptions to his local copy.
          */
 
-        if (local->nb_blocks != nb_remote_blocks) {
+        if (local->nb_blocks != nb_dest_blocks) {
             ERROR(errp, "ram blocks mismatch #1! "
                         "Your QEMU command line parameters are probably "
                         "not identical on both the source and destination.");
@@ -3184,26 +3190,26 @@ static int qemu_rdma_registration_stop(QEMUFile *f, void *opaque,
         }
 
         qemu_rdma_move_header(rdma, reg_result_idx, &resp);
-        memcpy(rdma->block,
+        memcpy(rdma->dest_blocks,
             rdma->wr_data[reg_result_idx].control_curr, resp.len);
-        for (i = 0; i < nb_remote_blocks; i++) {
-            network_to_remote_block(&rdma->block[i]);
+        for (i = 0; i < nb_dest_blocks; i++) {
+            network_to_dest_block(&rdma->dest_blocks[i]);
 
             /* search local ram blocks */
             for (j = 0; j < local->nb_blocks; j++) {
-                if (rdma->block[i].offset != local->block[j].offset) {
+                if (rdma->dest_blocks[i].offset != local->block[j].offset) {
                     continue;
                 }
 
-                if (rdma->block[i].length != local->block[j].length) {
+                if (rdma->dest_blocks[i].length != local->block[j].length) {
                     ERROR(errp, "ram blocks mismatch #2! "
                         "Your QEMU command line parameters are probably "
                         "not identical on both the source and destination.");
                     return -EINVAL;
                 }
                 local->block[j].remote_host_addr =
-                        rdma->block[i].remote_host_addr;
-                local->block[j].remote_rkey = rdma->block[i].remote_rkey;
+                        rdma->dest_blocks[i].remote_host_addr;
+                local->block[j].remote_rkey = rdma->dest_blocks[i].remote_rkey;
                 break;
             }
 
diff --git a/savevm.c b/migration/savevm.c
index 3b0e222cb3..2091882196 100644
--- a/savevm.c
+++ b/migration/savevm.c
@@ -2,6 +2,10 @@
  * QEMU System Emulator
  *
  * Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (c) 2009-2015 Red Hat Inc
+ *
+ * Authors:
+ *  Juan Quintela <quintela@redhat.com>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -51,6 +55,8 @@
 #define ARP_PTYPE_IP 0x0800
 #define ARP_OP_REQUEST_REV 0x3
 
+static bool skip_section_footers;
+
 static int announce_self_create(uint8_t *buf,
                                 uint8_t *mac_addr)
 {
@@ -235,10 +241,15 @@ typedef struct SaveStateEntry {
     int is_ram;
 } SaveStateEntry;
 
+typedef struct SaveState {
+    QTAILQ_HEAD(, SaveStateEntry) handlers;
+    int global_section_id;
+} SaveState;
 
-static QTAILQ_HEAD(savevm_handlers, SaveStateEntry) savevm_handlers =
-    QTAILQ_HEAD_INITIALIZER(savevm_handlers);
-static int global_section_id;
+static SaveState savevm_state = {
+    .handlers = QTAILQ_HEAD_INITIALIZER(savevm_state.handlers),
+    .global_section_id = 0,
+};
 
 static void dump_vmstate_vmsd(FILE *out_file,
                               const VMStateDescription *vmsd, int indent,
@@ -263,11 +274,11 @@ static void dump_vmstate_vmsf(FILE *out_file, const VMStateField *field,
 }
 
 static void dump_vmstate_vmss(FILE *out_file,
-                              const VMStateSubsection *subsection,
+                              const VMStateDescription **subsection,
                               int indent)
 {
-    if (subsection->vmsd != NULL) {
-        dump_vmstate_vmsd(out_file, subsection->vmsd, indent, true);
+    if (*subsection != NULL) {
+        dump_vmstate_vmsd(out_file, *subsection, indent, true);
     }
 }
 
@@ -308,12 +319,12 @@ static void dump_vmstate_vmsd(FILE *out_file,
         fprintf(out_file, "\n%*s]", indent, "");
     }
     if (vmsd->subsections != NULL) {
-        const VMStateSubsection *subsection = vmsd->subsections;
+        const VMStateDescription **subsection = vmsd->subsections;
         bool first;
 
         fprintf(out_file, ",\n%*s\"Subsections\": [\n", indent, "");
         first = true;
-        while (subsection->vmsd != NULL) {
+        while (*subsection != NULL) {
             if (!first) {
                 fprintf(out_file, ",\n");
             }
@@ -383,7 +394,7 @@ static int calculate_new_instance_id(const char *idstr)
     SaveStateEntry *se;
     int instance_id = 0;
 
-    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (strcmp(idstr, se->idstr) == 0
             && instance_id <= se->instance_id) {
             instance_id = se->instance_id + 1;
@@ -397,7 +408,7 @@ static int calculate_compat_instance_id(const char *idstr)
     SaveStateEntry *se;
     int instance_id = 0;
 
-    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (!se->compat) {
             continue;
         }
@@ -425,7 +436,7 @@ int register_savevm_live(DeviceState *dev,
 
     se = g_malloc0(sizeof(SaveStateEntry));
     se->version_id = version_id;
-    se->section_id = global_section_id++;
+    se->section_id = savevm_state.global_section_id++;
     se->ops = ops;
     se->opaque = opaque;
     se->vmsd = NULL;
@@ -457,7 +468,7 @@ int register_savevm_live(DeviceState *dev,
     }
     assert(!se->compat || se->instance_id == 0);
     /* add at the end of list */
-    QTAILQ_INSERT_TAIL(&savevm_handlers, se, entry);
+    QTAILQ_INSERT_TAIL(&savevm_state.handlers, se, entry);
     return 0;
 }
 
@@ -491,9 +502,9 @@ void unregister_savevm(DeviceState *dev, const char *idstr, void *opaque)
     }
     pstrcat(id, sizeof(id), idstr);
 
-    QTAILQ_FOREACH_SAFE(se, &savevm_handlers, entry, new_se) {
+    QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) {
         if (strcmp(se->idstr, id) == 0 && se->opaque == opaque) {
-            QTAILQ_REMOVE(&savevm_handlers, se, entry);
+            QTAILQ_REMOVE(&savevm_state.handlers, se, entry);
             if (se->compat) {
                 g_free(se->compat);
             }
@@ -515,7 +526,7 @@ int vmstate_register_with_alias_id(DeviceState *dev, int instance_id,
 
     se = g_malloc0(sizeof(SaveStateEntry));
     se->version_id = vmsd->version_id;
-    se->section_id = global_section_id++;
+    se->section_id = savevm_state.global_section_id++;
     se->opaque = opaque;
     se->vmsd = vmsd;
     se->alias_id = alias_id;
@@ -543,7 +554,7 @@ int vmstate_register_with_alias_id(DeviceState *dev, int instance_id,
     }
     assert(!se->compat || se->instance_id == 0);
     /* add at the end of list */
-    QTAILQ_INSERT_TAIL(&savevm_handlers, se, entry);
+    QTAILQ_INSERT_TAIL(&savevm_state.handlers, se, entry);
     return 0;
 }
 
@@ -552,9 +563,9 @@ void vmstate_unregister(DeviceState *dev, const VMStateDescription *vmsd,
 {
     SaveStateEntry *se, *new_se;
 
-    QTAILQ_FOREACH_SAFE(se, &savevm_handlers, entry, new_se) {
+    QTAILQ_FOREACH_SAFE(se, &savevm_state.handlers, entry, new_se) {
         if (se->vmsd == vmsd && se->opaque == opaque) {
-            QTAILQ_REMOVE(&savevm_handlers, se, entry);
+            QTAILQ_REMOVE(&savevm_state.handlers, se, entry);
             if (se->compat) {
                 g_free(se->compat);
             }
@@ -602,11 +613,84 @@ static void vmstate_save(QEMUFile *f, SaveStateEntry *se, QJSON *vmdesc)
     vmstate_save_state(f, se->vmsd, se->opaque, vmdesc);
 }
 
+void savevm_skip_section_footers(void)
+{
+    skip_section_footers = true;
+}
+
+/*
+ * Write the header for device section (QEMU_VM_SECTION START/END/PART/FULL)
+ */
+static void save_section_header(QEMUFile *f, SaveStateEntry *se,
+                                uint8_t section_type)
+{
+    qemu_put_byte(f, section_type);
+    qemu_put_be32(f, se->section_id);
+
+    if (section_type == QEMU_VM_SECTION_FULL ||
+        section_type == QEMU_VM_SECTION_START) {
+        /* ID string */
+        size_t len = strlen(se->idstr);
+        qemu_put_byte(f, len);
+        qemu_put_buffer(f, (uint8_t *)se->idstr, len);
+
+        qemu_put_be32(f, se->instance_id);
+        qemu_put_be32(f, se->version_id);
+    }
+}
+
+/*
+ * Write a footer onto device sections that catches cases misformatted device
+ * sections.
+ */
+static void save_section_footer(QEMUFile *f, SaveStateEntry *se)
+{
+    if (!skip_section_footers) {
+        qemu_put_byte(f, QEMU_VM_SECTION_FOOTER);
+        qemu_put_be32(f, se->section_id);
+    }
+}
+
+/*
+ * Read a footer off the wire and check that it matches the expected section
+ *
+ * Returns: true if the footer was good
+ *          false if there is a problem (and calls error_report to say why)
+ */
+static bool check_section_footer(QEMUFile *f, SaveStateEntry *se)
+{
+    uint8_t read_mark;
+    uint32_t read_section_id;
+
+    if (skip_section_footers) {
+        /* No footer to check */
+        return true;
+    }
+
+    read_mark = qemu_get_byte(f);
+
+    if (read_mark != QEMU_VM_SECTION_FOOTER) {
+        error_report("Missing section footer for %s", se->idstr);
+        return false;
+    }
+
+    read_section_id = qemu_get_be32(f);
+    if (read_section_id != se->section_id) {
+        error_report("Mismatched section id in footer for %s -"
+                     " read 0x%x expected 0x%x",
+                     se->idstr, read_section_id, se->section_id);
+        return false;
+    }
+
+    /* All good */
+    return true;
+}
+
 bool qemu_savevm_state_blocked(Error **errp)
 {
     SaveStateEntry *se;
 
-    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (se->vmsd && se->vmsd->unmigratable) {
             error_setg(errp, "State blocked by non-migratable device '%s'",
                        se->idstr);
@@ -616,6 +700,13 @@ bool qemu_savevm_state_blocked(Error **errp)
     return false;
 }
 
+void qemu_savevm_state_header(QEMUFile *f)
+{
+    trace_savevm_state_header();
+    qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
+    qemu_put_be32(f, QEMU_VM_FILE_VERSION);
+}
+
 void qemu_savevm_state_begin(QEMUFile *f,
                              const MigrationParams *params)
 {
@@ -623,19 +714,14 @@ void qemu_savevm_state_begin(QEMUFile *f,
     int ret;
 
     trace_savevm_state_begin();
-    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (!se->ops || !se->ops->set_params) {
             continue;
         }
         se->ops->set_params(params, se->opaque);
     }
 
-    qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
-    qemu_put_be32(f, QEMU_VM_FILE_VERSION);
-
-    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
-        int len;
-
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (!se->ops || !se->ops->save_live_setup) {
             continue;
         }
@@ -644,19 +730,10 @@ void qemu_savevm_state_begin(QEMUFile *f,
                 continue;
             }
         }
-        /* Section type */
-        qemu_put_byte(f, QEMU_VM_SECTION_START);
-        qemu_put_be32(f, se->section_id);
-
-        /* ID string */
-        len = strlen(se->idstr);
-        qemu_put_byte(f, len);
-        qemu_put_buffer(f, (uint8_t *)se->idstr, len);
-
-        qemu_put_be32(f, se->instance_id);
-        qemu_put_be32(f, se->version_id);
+        save_section_header(f, se, QEMU_VM_SECTION_START);
 
         ret = se->ops->save_live_setup(f, se->opaque);
+        save_section_footer(f, se);
         if (ret < 0) {
             qemu_file_set_error(f, ret);
             break;
@@ -676,7 +753,7 @@ int qemu_savevm_state_iterate(QEMUFile *f)
     int ret = 1;
 
     trace_savevm_state_iterate();
-    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (!se->ops || !se->ops->save_live_iterate) {
             continue;
         }
@@ -689,12 +766,12 @@ int qemu_savevm_state_iterate(QEMUFile *f)
             return 0;
         }
         trace_savevm_section_start(se->idstr, se->section_id);
-        /* Section type */
-        qemu_put_byte(f, QEMU_VM_SECTION_PART);
-        qemu_put_be32(f, se->section_id);
+
+        save_section_header(f, se, QEMU_VM_SECTION_PART);
 
         ret = se->ops->save_live_iterate(f, se->opaque);
         trace_savevm_section_end(se->idstr, se->section_id, ret);
+        save_section_footer(f, se);
 
         if (ret < 0) {
             qemu_file_set_error(f, ret);
@@ -727,7 +804,7 @@ void qemu_savevm_state_complete(QEMUFile *f)
 
     cpu_synchronize_all_states();
 
-    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (!se->ops || !se->ops->save_live_complete) {
             continue;
         }
@@ -737,12 +814,12 @@ void qemu_savevm_state_complete(QEMUFile *f)
             }
         }
         trace_savevm_section_start(se->idstr, se->section_id);
-        /* Section type */
-        qemu_put_byte(f, QEMU_VM_SECTION_END);
-        qemu_put_be32(f, se->section_id);
+
+        save_section_header(f, se, QEMU_VM_SECTION_END);
 
         ret = se->ops->save_live_complete(f, se->opaque);
         trace_savevm_section_end(se->idstr, se->section_id, ret);
+        save_section_footer(f, se);
         if (ret < 0) {
             qemu_file_set_error(f, ret);
             return;
@@ -752,8 +829,7 @@ void qemu_savevm_state_complete(QEMUFile *f)
     vmdesc = qjson_new();
     json_prop_int(vmdesc, "page_size", TARGET_PAGE_SIZE);
     json_start_array(vmdesc, "devices");
-    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
-        int len;
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
 
         if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
             continue;
@@ -764,22 +840,13 @@ void qemu_savevm_state_complete(QEMUFile *f)
         json_prop_str(vmdesc, "name", se->idstr);
         json_prop_int(vmdesc, "instance_id", se->instance_id);
 
-        /* Section type */
-        qemu_put_byte(f, QEMU_VM_SECTION_FULL);
-        qemu_put_be32(f, se->section_id);
-
-        /* ID string */
-        len = strlen(se->idstr);
-        qemu_put_byte(f, len);
-        qemu_put_buffer(f, (uint8_t *)se->idstr, len);
-
-        qemu_put_be32(f, se->instance_id);
-        qemu_put_be32(f, se->version_id);
+        save_section_header(f, se, QEMU_VM_SECTION_FULL);
 
         vmstate_save(f, se, vmdesc);
 
         json_end_object(vmdesc);
         trace_savevm_section_end(se->idstr, se->section_id, 0);
+        save_section_footer(f, se);
     }
 
     qemu_put_byte(f, QEMU_VM_EOF);
@@ -803,7 +870,7 @@ uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size)
     SaveStateEntry *se;
     uint64_t ret = 0;
 
-    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (!se->ops || !se->ops->save_live_pending) {
             continue;
         }
@@ -822,7 +889,7 @@ void qemu_savevm_state_cancel(void)
     SaveStateEntry *se;
 
     trace_savevm_state_cancel();
-    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (se->ops && se->ops->cancel) {
             se->ops->cancel(se->opaque);
         }
@@ -842,6 +909,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
     }
 
     qemu_mutex_unlock_iothread();
+    qemu_savevm_state_header(f);
     qemu_savevm_state_begin(f, &params);
     qemu_mutex_lock_iothread();
 
@@ -872,9 +940,7 @@ static int qemu_save_device_state(QEMUFile *f)
 
     cpu_synchronize_all_states();
 
-    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
-        int len;
-
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (se->is_ram) {
             continue;
         }
@@ -882,19 +948,11 @@ static int qemu_save_device_state(QEMUFile *f)
             continue;
         }
 
-        /* Section type */
-        qemu_put_byte(f, QEMU_VM_SECTION_FULL);
-        qemu_put_be32(f, se->section_id);
-
-        /* ID string */
-        len = strlen(se->idstr);
-        qemu_put_byte(f, len);
-        qemu_put_buffer(f, (uint8_t *)se->idstr, len);
-
-        qemu_put_be32(f, se->instance_id);
-        qemu_put_be32(f, se->version_id);
+        save_section_header(f, se, QEMU_VM_SECTION_FULL);
 
         vmstate_save(f, se, NULL);
+
+        save_section_footer(f, se);
     }
 
     qemu_put_byte(f, QEMU_VM_EOF);
@@ -906,7 +964,7 @@ static SaveStateEntry *find_se(const char *idstr, int instance_id)
 {
     SaveStateEntry *se;
 
-    QTAILQ_FOREACH(se, &savevm_handlers, entry) {
+    QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (!strcmp(se->idstr, idstr) &&
             (instance_id == se->instance_id ||
              instance_id == se->alias_id))
@@ -922,18 +980,26 @@ static SaveStateEntry *find_se(const char *idstr, int instance_id)
     return NULL;
 }
 
-typedef struct LoadStateEntry {
+struct LoadStateEntry {
     QLIST_ENTRY(LoadStateEntry) entry;
     SaveStateEntry *se;
     int section_id;
     int version_id;
-} LoadStateEntry;
+};
 
-int qemu_loadvm_state(QEMUFile *f)
+void loadvm_free_handlers(MigrationIncomingState *mis)
 {
-    QLIST_HEAD(, LoadStateEntry) loadvm_handlers =
-        QLIST_HEAD_INITIALIZER(loadvm_handlers);
     LoadStateEntry *le, *new_le;
+
+    QLIST_FOREACH_SAFE(le, &mis->loadvm_handlers, entry, new_le) {
+        QLIST_REMOVE(le, entry);
+        g_free(le);
+    }
+}
+
+int qemu_loadvm_state(QEMUFile *f)
+{
+    MigrationIncomingState *mis = migration_incoming_get_current();
     Error *local_err = NULL;
     uint8_t section_type;
     unsigned int v;
@@ -964,8 +1030,8 @@ int qemu_loadvm_state(QEMUFile *f)
     while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
         uint32_t instance_id, version_id, section_id;
         SaveStateEntry *se;
-        char idstr[257];
-        int len;
+        LoadStateEntry *le;
+        char idstr[256];
 
         trace_qemu_loadvm_state_section(section_type);
         switch (section_type) {
@@ -973,9 +1039,11 @@ int qemu_loadvm_state(QEMUFile *f)
         case QEMU_VM_SECTION_FULL:
             /* Read section start */
             section_id = qemu_get_be32(f);
-            len = qemu_get_byte(f);
-            qemu_get_buffer(f, (uint8_t *)idstr, len);
-            idstr[len] = 0;
+            if (!qemu_get_counted_string(f, idstr)) {
+                error_report("Unable to read ID string for section %u",
+                            section_id);
+                return -EINVAL;
+            }
             instance_id = qemu_get_be32(f);
             version_id = qemu_get_be32(f);
 
@@ -1004,7 +1072,7 @@ int qemu_loadvm_state(QEMUFile *f)
             le->se = se;
             le->section_id = section_id;
             le->version_id = version_id;
-            QLIST_INSERT_HEAD(&loadvm_handlers, le, entry);
+            QLIST_INSERT_HEAD(&mis->loadvm_handlers, le, entry);
 
             ret = vmstate_load(f, le->se, le->version_id);
             if (ret < 0) {
@@ -1012,13 +1080,17 @@ int qemu_loadvm_state(QEMUFile *f)
                              " device '%s'", instance_id, idstr);
                 goto out;
             }
+            if (!check_section_footer(f, le->se)) {
+                ret = -EINVAL;
+                goto out;
+            }
             break;
         case QEMU_VM_SECTION_PART:
         case QEMU_VM_SECTION_END:
             section_id = qemu_get_be32(f);
 
             trace_qemu_loadvm_state_section_partend(section_id);
-            QLIST_FOREACH(le, &loadvm_handlers, entry) {
+            QLIST_FOREACH(le, &mis->loadvm_handlers, entry) {
                 if (le->section_id == section_id) {
                     break;
                 }
@@ -1035,6 +1107,10 @@ int qemu_loadvm_state(QEMUFile *f)
                              section_id, le->se->idstr);
                 goto out;
             }
+            if (!check_section_footer(f, le->se)) {
+                ret = -EINVAL;
+                goto out;
+            }
             break;
         default:
             error_report("Unknown savevm section type %d", section_type);
@@ -1066,11 +1142,6 @@ int qemu_loadvm_state(QEMUFile *f)
     ret = 0;
 
 out:
-    QLIST_FOREACH_SAFE(le, &loadvm_handlers, entry, new_le) {
-        QLIST_REMOVE(le, entry);
-        g_free(le);
-    }
-
     if (ret == 0) {
         /* We may not have a VMDESC section, so ignore relative errors */
         ret = file_error_after_eof;
@@ -1314,9 +1385,11 @@ int load_vmstate(const char *name)
     }
 
     qemu_system_reset(VMRESET_SILENT);
+    migration_incoming_state_new(f);
     ret = qemu_loadvm_state(f);
 
     qemu_fclose(f);
+    migration_incoming_state_destroy();
     if (ret < 0) {
         error_report("Error %d while loading VM state", ret);
         return ret;
diff --git a/migration/vmstate.c b/migration/vmstate.c
index e5388f0596..6138d1acb7 100644
--- a/migration/vmstate.c
+++ b/migration/vmstate.c
@@ -341,11 +341,11 @@ void vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd,
 }
 
 static const VMStateDescription *
-    vmstate_get_subsection(const VMStateSubsection *sub, char *idstr)
+vmstate_get_subsection(const VMStateDescription **sub, char *idstr)
 {
-    while (sub && sub->needed) {
-        if (strcmp(idstr, sub->vmsd->name) == 0) {
-            return sub->vmsd;
+    while (sub && *sub && (*sub)->needed) {
+        if (strcmp(idstr, (*sub)->name) == 0) {
+            return *sub;
         }
         sub++;
     }
@@ -358,7 +358,7 @@ static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
     trace_vmstate_subsection_load(vmsd->name);
 
     while (qemu_peek_byte(f, 0) == QEMU_VM_SUBSECTION) {
-        char idstr[256];
+        char idstr[256], *idstr_ret;
         int ret;
         uint8_t version_id, len, size;
         const VMStateDescription *sub_vmsd;
@@ -369,11 +369,12 @@ static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
             trace_vmstate_subsection_load_bad(vmsd->name, "(short)");
             return 0;
         }
-        size = qemu_peek_buffer(f, (uint8_t *)idstr, len, 2);
+        size = qemu_peek_buffer(f, (uint8_t **)&idstr_ret, len, 2);
         if (size != len) {
             trace_vmstate_subsection_load_bad(vmsd->name, "(peek fail)");
             return 0;
         }
+        memcpy(idstr, idstr_ret, size);
         idstr[size] = 0;
 
         if (strncmp(vmsd->name, idstr, strlen(vmsd->name)) != 0) {
@@ -405,12 +406,12 @@ static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
 static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd,
                                     void *opaque, QJSON *vmdesc)
 {
-    const VMStateSubsection *sub = vmsd->subsections;
+    const VMStateDescription **sub = vmsd->subsections;
     bool subsection_found = false;
 
-    while (sub && sub->needed) {
-        if (sub->needed(opaque)) {
-            const VMStateDescription *vmsd = sub->vmsd;
+    while (sub && *sub && (*sub)->needed) {
+        if ((*sub)->needed(opaque)) {
+            const VMStateDescription *vmsd = *sub;
             uint8_t len;
 
             if (vmdesc) {
diff --git a/scripts/analyze-migration.py b/scripts/analyze-migration.py
index 0c8b22f2aa..f6894bece9 100755
--- a/scripts/analyze-migration.py
+++ b/scripts/analyze-migration.py
@@ -474,6 +474,7 @@ class MigrationDump(object):
     QEMU_VM_SECTION_FULL  = 0x04
     QEMU_VM_SUBSECTION    = 0x05
     QEMU_VM_VMDESCRIPTION = 0x06
+    QEMU_VM_SECTION_FOOTER= 0x7e
 
     def __init__(self, filename):
         self.section_classes = { ( 'ram', 0 ) : [ RamSection, None ],
@@ -526,6 +527,10 @@ class MigrationDump(object):
             elif section_type == self.QEMU_VM_SECTION_PART or section_type == self.QEMU_VM_SECTION_END:
                 section_id = file.read32()
                 self.sections[section_id].read()
+            elif section_type == self.QEMU_VM_SECTION_FOOTER:
+                read_section_id = file.read32()
+                if read_section_id != section_id:
+                    raise Exception("Mismatched section footer: %x vs %x" % (read_section_id, section_id))
             else:
                 raise Exception("Unknown section type: %d" % section_type)
         file.close()
diff --git a/target-arm/machine.c b/target-arm/machine.c
index 9446e5a8ab..36365a57c7 100644
--- a/target-arm/machine.c
+++ b/target-arm/machine.c
@@ -40,6 +40,7 @@ static const VMStateDescription vmstate_vfp = {
     .name = "cpu/vfp",
     .version_id = 3,
     .minimum_version_id = 3,
+    .needed = vfp_needed,
     .fields = (VMStateField[]) {
         VMSTATE_FLOAT64_ARRAY(env.vfp.regs, ARMCPU, 64),
         /* The xregs array is a little awkward because element 1 (FPSCR)
@@ -72,6 +73,7 @@ static const VMStateDescription vmstate_iwmmxt = {
     .name = "cpu/iwmmxt",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = iwmmxt_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64_ARRAY(env.iwmmxt.regs, ARMCPU, 16),
         VMSTATE_UINT32_ARRAY(env.iwmmxt.cregs, ARMCPU, 16),
@@ -91,6 +93,7 @@ static const VMStateDescription vmstate_m = {
     .name = "cpu/m",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = m_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(env.v7m.other_sp, ARMCPU),
         VMSTATE_UINT32(env.v7m.vecbase, ARMCPU),
@@ -114,6 +117,7 @@ static const VMStateDescription vmstate_thumb2ee = {
     .name = "cpu/thumb2ee",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = thumb2ee_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(env.teecr, ARMCPU),
         VMSTATE_UINT32(env.teehbr, ARMCPU),
@@ -282,21 +286,11 @@ const VMStateDescription vmstate_arm_cpu = {
         VMSTATE_BOOL(powered_off, ARMCPU),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_vfp,
-            .needed = vfp_needed,
-        } , {
-            .vmsd = &vmstate_iwmmxt,
-            .needed = iwmmxt_needed,
-        } , {
-            .vmsd = &vmstate_m,
-            .needed = m_needed,
-        } , {
-            .vmsd = &vmstate_thumb2ee,
-            .needed = thumb2ee_needed,
-        } , {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_vfp,
+        &vmstate_iwmmxt,
+        &vmstate_m,
+        &vmstate_thumb2ee,
+        NULL
     }
 };
diff --git a/target-i386/machine.c b/target-i386/machine.c
index 69d86cb476..a0df64b577 100644
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -403,6 +403,7 @@ static const VMStateDescription vmstate_steal_time_msr = {
     .name = "cpu/steal_time_msr",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = steal_time_msr_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.steal_time_msr, X86CPU),
         VMSTATE_END_OF_LIST()
@@ -413,6 +414,7 @@ static const VMStateDescription vmstate_async_pf_msr = {
     .name = "cpu/async_pf_msr",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = async_pf_msr_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.async_pf_en_msr, X86CPU),
         VMSTATE_END_OF_LIST()
@@ -423,6 +425,7 @@ static const VMStateDescription vmstate_pv_eoi_msr = {
     .name = "cpu/async_pv_eoi_msr",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = pv_eoi_msr_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.pv_eoi_en_msr, X86CPU),
         VMSTATE_END_OF_LIST()
@@ -441,6 +444,7 @@ static const VMStateDescription vmstate_fpop_ip_dp = {
     .name = "cpu/fpop_ip_dp",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = fpop_ip_dp_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT16(env.fpop, X86CPU),
         VMSTATE_UINT64(env.fpip, X86CPU),
@@ -461,6 +465,7 @@ static const VMStateDescription vmstate_msr_tsc_adjust = {
     .name = "cpu/msr_tsc_adjust",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = tsc_adjust_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.tsc_adjust, X86CPU),
         VMSTATE_END_OF_LIST()
@@ -479,6 +484,7 @@ static const VMStateDescription vmstate_msr_tscdeadline = {
     .name = "cpu/msr_tscdeadline",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = tscdeadline_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.tsc_deadline, X86CPU),
         VMSTATE_END_OF_LIST()
@@ -505,6 +511,7 @@ static const VMStateDescription vmstate_msr_ia32_misc_enable = {
     .name = "cpu/msr_ia32_misc_enable",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = misc_enable_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.msr_ia32_misc_enable, X86CPU),
         VMSTATE_END_OF_LIST()
@@ -515,6 +522,7 @@ static const VMStateDescription vmstate_msr_ia32_feature_control = {
     .name = "cpu/msr_ia32_feature_control",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = feature_control_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.msr_ia32_feature_control, X86CPU),
         VMSTATE_END_OF_LIST()
@@ -549,6 +557,7 @@ static const VMStateDescription vmstate_msr_architectural_pmu = {
     .name = "cpu/msr_architectural_pmu",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = pmu_enable_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.msr_fixed_ctr_ctrl, X86CPU),
         VMSTATE_UINT64(env.msr_global_ctrl, X86CPU),
@@ -584,6 +593,7 @@ static const VMStateDescription vmstate_mpx = {
     .name = "cpu/mpx",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = mpx_needed,
     .fields = (VMStateField[]) {
         VMSTATE_BND_REGS(env.bnd_regs, X86CPU, 4),
         VMSTATE_UINT64(env.bndcs_regs.cfgu, X86CPU),
@@ -605,6 +615,7 @@ static const VMStateDescription vmstate_msr_hypercall_hypercall = {
     .name = "cpu/msr_hyperv_hypercall",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = hyperv_hypercall_enable_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.msr_hv_guest_os_id, X86CPU),
         VMSTATE_UINT64(env.msr_hv_hypercall, X86CPU),
@@ -624,6 +635,7 @@ static const VMStateDescription vmstate_msr_hyperv_vapic = {
     .name = "cpu/msr_hyperv_vapic",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = hyperv_vapic_enable_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.msr_hv_vapic, X86CPU),
         VMSTATE_END_OF_LIST()
@@ -642,6 +654,7 @@ static const VMStateDescription vmstate_msr_hyperv_time = {
     .name = "cpu/msr_hyperv_time",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = hyperv_time_enable_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.msr_hv_tsc, X86CPU),
         VMSTATE_END_OF_LIST()
@@ -683,6 +696,7 @@ static const VMStateDescription vmstate_avx512 = {
     .name = "cpu/avx512",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = avx512_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64_ARRAY(env.opmask_regs, X86CPU, NB_OPMASK_REGS),
         VMSTATE_ZMMH_REGS_VARS(env.xmm_regs, X86CPU, 0),
@@ -705,6 +719,7 @@ static const VMStateDescription vmstate_xss = {
     .name = "cpu/xss",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = xss_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.xss, X86CPU),
         VMSTATE_END_OF_LIST()
@@ -813,54 +828,22 @@ VMStateDescription vmstate_x86_cpu = {
         VMSTATE_END_OF_LIST()
         /* The above list is not sorted /wrt version numbers, watch out! */
     },
-    .subsections = (VMStateSubsection []) {
-        {
-            .vmsd = &vmstate_async_pf_msr,
-            .needed = async_pf_msr_needed,
-        } , {
-            .vmsd = &vmstate_pv_eoi_msr,
-            .needed = pv_eoi_msr_needed,
-        } , {
-            .vmsd = &vmstate_steal_time_msr,
-            .needed = steal_time_msr_needed,
-        } , {
-            .vmsd = &vmstate_fpop_ip_dp,
-            .needed = fpop_ip_dp_needed,
-        }, {
-            .vmsd = &vmstate_msr_tsc_adjust,
-            .needed = tsc_adjust_needed,
-        }, {
-            .vmsd = &vmstate_msr_tscdeadline,
-            .needed = tscdeadline_needed,
-        }, {
-            .vmsd = &vmstate_msr_ia32_misc_enable,
-            .needed = misc_enable_needed,
-        }, {
-            .vmsd = &vmstate_msr_ia32_feature_control,
-            .needed = feature_control_needed,
-        }, {
-            .vmsd = &vmstate_msr_architectural_pmu,
-            .needed = pmu_enable_needed,
-        } , {
-            .vmsd = &vmstate_mpx,
-            .needed = mpx_needed,
-        }, {
-            .vmsd = &vmstate_msr_hypercall_hypercall,
-            .needed = hyperv_hypercall_enable_needed,
-        }, {
-            .vmsd = &vmstate_msr_hyperv_vapic,
-            .needed = hyperv_vapic_enable_needed,
-        }, {
-            .vmsd = &vmstate_msr_hyperv_time,
-            .needed = hyperv_time_enable_needed,
-        }, {
-            .vmsd = &vmstate_avx512,
-            .needed = avx512_needed,
-         }, {
-            .vmsd = &vmstate_xss,
-            .needed = xss_needed,
-        } , {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_async_pf_msr,
+        &vmstate_pv_eoi_msr,
+        &vmstate_steal_time_msr,
+        &vmstate_fpop_ip_dp,
+        &vmstate_msr_tsc_adjust,
+        &vmstate_msr_tscdeadline,
+        &vmstate_msr_ia32_misc_enable,
+        &vmstate_msr_ia32_feature_control,
+        &vmstate_msr_architectural_pmu,
+        &vmstate_mpx,
+        &vmstate_msr_hypercall_hypercall,
+        &vmstate_msr_hyperv_vapic,
+        &vmstate_msr_hyperv_time,
+        &vmstate_avx512,
+        &vmstate_xss,
+        NULL
     }
 };
diff --git a/target-ppc/machine.c b/target-ppc/machine.c
index d875211a2d..f4ac7611dd 100644
--- a/target-ppc/machine.c
+++ b/target-ppc/machine.c
@@ -213,6 +213,7 @@ static const VMStateDescription vmstate_fpu = {
     .name = "cpu/fpu",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = fpu_needed,
     .fields = (VMStateField[]) {
         VMSTATE_FLOAT64_ARRAY(env.fpr, PowerPCCPU, 32),
         VMSTATE_UINTTL(env.fpscr, PowerPCCPU),
@@ -231,6 +232,7 @@ static const VMStateDescription vmstate_altivec = {
     .name = "cpu/altivec",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = altivec_needed,
     .fields = (VMStateField[]) {
         VMSTATE_AVR_ARRAY(env.avr, PowerPCCPU, 32),
         VMSTATE_UINT32(env.vscr, PowerPCCPU),
@@ -249,6 +251,7 @@ static const VMStateDescription vmstate_vsx = {
     .name = "cpu/vsx",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = vsx_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64_ARRAY(env.vsr, PowerPCCPU, 32),
         VMSTATE_END_OF_LIST()
@@ -269,6 +272,7 @@ static const VMStateDescription vmstate_tm = {
     .version_id = 1,
     .minimum_version_id = 1,
     .minimum_version_id_old = 1,
+    .needed = tm_needed,
     .fields      = (VMStateField []) {
         VMSTATE_UINTTL_ARRAY(env.tm_gpr, PowerPCCPU, 32),
         VMSTATE_AVR_ARRAY(env.tm_vsr, PowerPCCPU, 64),
@@ -302,6 +306,7 @@ static const VMStateDescription vmstate_sr = {
     .name = "cpu/sr",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = sr_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINTTL_ARRAY(env.sr, PowerPCCPU, 32),
         VMSTATE_END_OF_LIST()
@@ -351,6 +356,7 @@ static const VMStateDescription vmstate_slb = {
     .name = "cpu/slb",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = slb_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32_EQUAL(env.slb_nr, PowerPCCPU),
         VMSTATE_SLB_ARRAY(env.slb, PowerPCCPU, MAX_SLB_ENTRIES),
@@ -383,6 +389,7 @@ static const VMStateDescription vmstate_tlb6xx = {
     .name = "cpu/tlb6xx",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = tlb6xx_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32_EQUAL(env.nb_tlb, PowerPCCPU),
         VMSTATE_STRUCT_VARRAY_POINTER_INT32(env.tlb.tlb6, PowerPCCPU,
@@ -429,6 +436,7 @@ static const VMStateDescription vmstate_pbr403 = {
     .name = "cpu/pbr403",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = pbr403_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINTTL_ARRAY(env.pb, PowerPCCPU, 4),
         VMSTATE_END_OF_LIST()
@@ -439,6 +447,7 @@ static const VMStateDescription vmstate_tlbemb = {
     .name = "cpu/tlb6xx",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = tlbemb_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32_EQUAL(env.nb_tlb, PowerPCCPU),
         VMSTATE_STRUCT_VARRAY_POINTER_INT32(env.tlb.tlbe, PowerPCCPU,
@@ -448,13 +457,9 @@ static const VMStateDescription vmstate_tlbemb = {
         /* 403 protection registers */
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection []) {
-        {
-            .vmsd = &vmstate_pbr403,
-            .needed = pbr403_needed,
-        } , {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_pbr403,
+        NULL
     }
 };
 
@@ -483,6 +488,7 @@ static const VMStateDescription vmstate_tlbmas = {
     .name = "cpu/tlbmas",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = tlbmas_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT32_EQUAL(env.nb_tlb, PowerPCCPU),
         VMSTATE_STRUCT_VARRAY_POINTER_INT32(env.tlb.tlbm, PowerPCCPU,
@@ -533,38 +539,18 @@ const VMStateDescription vmstate_ppc_cpu = {
         VMSTATE_UINT32_EQUAL(env.nb_BATs, PowerPCCPU),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection []) {
-        {
-            .vmsd = &vmstate_fpu,
-            .needed = fpu_needed,
-        } , {
-            .vmsd = &vmstate_altivec,
-            .needed = altivec_needed,
-        } , {
-            .vmsd = &vmstate_vsx,
-            .needed = vsx_needed,
-        } , {
-            .vmsd = &vmstate_sr,
-            .needed = sr_needed,
-        } , {
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_fpu,
+        &vmstate_altivec,
+        &vmstate_vsx,
+        &vmstate_sr,
 #ifdef TARGET_PPC64
-            .vmsd = &vmstate_tm,
-            .needed = tm_needed,
-        } , {
-            .vmsd = &vmstate_slb,
-            .needed = slb_needed,
-        } , {
+        &vmstate_tm,
+        &vmstate_slb,
 #endif /* TARGET_PPC64 */
-            .vmsd = &vmstate_tlb6xx,
-            .needed = tlb6xx_needed,
-        } , {
-            .vmsd = &vmstate_tlbemb,
-            .needed = tlbemb_needed,
-        } , {
-            .vmsd = &vmstate_tlbmas,
-            .needed = tlbmas_needed,
-        } , {
-            /* empty */
-        }
+        &vmstate_tlb6xx,
+        &vmstate_tlbemb,
+        &vmstate_tlbmas,
+        NULL
     }
 };
diff --git a/target-s390x/machine.c b/target-s390x/machine.c
index 004474959a..b76fb08319 100644
--- a/target-s390x/machine.c
+++ b/target-s390x/machine.c
@@ -42,10 +42,17 @@ static void cpu_pre_save(void *opaque)
     }
 }
 
+static inline bool fpu_needed(void *opaque)
+{
+    /* This looks odd, but we might want to NOT transfer fprs in the future */
+    return true;
+}
+
 const VMStateDescription vmstate_fpu = {
     .name = "cpu/fpu",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = fpu_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT64(env.vregs[0][0].ll, S390CPU),
         VMSTATE_UINT64(env.vregs[1][0].ll, S390CPU),
@@ -68,16 +75,11 @@ const VMStateDescription vmstate_fpu = {
     }
 };
 
-static inline bool fpu_needed(void *opaque)
-{
-    /* This looks odd, but we might want to NOT transfer fprs in the future */
-    return true;
-}
-
 const VMStateDescription vmstate_vregs = {
     .name = "cpu/vregs",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = vregs_needed,
     .fields = (VMStateField[]) {
         /* vregs[0][0] -> vregs[15][0] and fregs are overlays */
         VMSTATE_UINT64(env.vregs[16][0].ll, S390CPU),
@@ -159,16 +161,10 @@ const VMStateDescription vmstate_s390_cpu = {
         VMSTATE_VBUFFER_UINT32(irqstate, S390CPU, 4, NULL, 0,
                                irqstate_saved_size),
         VMSTATE_END_OF_LIST()
-     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &vmstate_fpu,
-            .needed = fpu_needed,
-        } , {
-            .vmsd = &vmstate_vregs,
-            .needed = vregs_needed,
-        } , {
-            /* empty */
-        }
+    },
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_fpu,
+        &vmstate_vregs,
+        NULL
     },
 };
diff --git a/trace-events b/trace-events
index 2662ffa850..1abca7a1e5 100644
--- a/trace-events
+++ b/trace-events
@@ -1179,13 +1179,14 @@ virtio_gpu_cmd_res_flush(uint32_t res, uint32_t w, uint32_t h, uint32_t x, uint3
 virtio_gpu_fence_ctrl(uint64_t fence, uint32_t type) "fence 0x%" PRIx64 ", type 0x%x"
 virtio_gpu_fence_resp(uint64_t fence) "fence 0x%" PRIx64
 
-# savevm.c
+# migration/savevm.c
 qemu_loadvm_state_section(unsigned int section_type) "%d"
 qemu_loadvm_state_section_partend(uint32_t section_id) "%u"
 qemu_loadvm_state_section_startfull(uint32_t section_id, const char *idstr, uint32_t instance_id, uint32_t version_id) "%u(%s) %u %u"
 savevm_section_start(const char *id, unsigned int section_id) "%s, section_id %u"
 savevm_section_end(const char *id, unsigned int section_id, int ret) "%s, section_id %u -> %d"
 savevm_state_begin(void) ""
+savevm_state_header(void) ""
 savevm_state_iterate(void) ""
 savevm_state_complete(void) ""
 savevm_state_cancel(void) ""
@@ -1205,7 +1206,7 @@ vmstate_subsection_load_good(const char *parent) "%s"
 # qemu-file.c
 qemu_file_fclose(void) ""
 
-# arch_init.c
+# migration/ram.c
 migration_bitmap_sync_start(void) ""
 migration_bitmap_sync_end(uint64_t dirty_pages) "dirty_pages %" PRIu64""
 migration_throttle(void) ""