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Re: [Qemu-devel] [PATCH] migration: move ram migration support
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH] migration: move ram migration support |
Date: |
Wed, 06 Mar 2013 17:55:13 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130219 Thunderbird/17.0.3 |
Il 06/03/2013 17:52, Michael S. Tsirkin ha scritto:
> Move RAM migration code from arch_init to migration-ram.
> This is just code reorganization, no functional changes.
>
> Signed-off-by: Michael S. Tsirkin <address@hidden>
Please make it savevm-ram.c, it is not limited to migration and the
common code is in savevm.c.
You'll also have to rebase it on top of
git://repo.or.cz/qemu/quintela.git, branch migration.next.
Paolo
> ---
> Makefile.target | 2 +-
> arch_init.c | 758 -----------------------------------------------------
> migration-ram.c | 799
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 800 insertions(+), 759 deletions(-)
> create mode 100644 migration-ram.c
>
> diff --git a/Makefile.target b/Makefile.target
> index ca657b3..a3292c8 100644
> --- a/Makefile.target
> +++ b/Makefile.target
> @@ -108,7 +108,7 @@ CONFIG_NO_XEN = $(if $(subst n,,$(CONFIG_XEN)),n,y)
> CONFIG_NO_GET_MEMORY_MAPPING = $(if $(subst
> n,,$(CONFIG_HAVE_GET_MEMORY_MAPPING)),n,y)
> CONFIG_NO_CORE_DUMP = $(if $(subst n,,$(CONFIG_HAVE_CORE_DUMP)),n,y)
>
> -obj-y += arch_init.o cpus.o monitor.o gdbstub.o balloon.o ioport.o
> +obj-y += arch_init.o cpus.o monitor.o gdbstub.o balloon.o ioport.o
> migration-ram.o
> obj-y += qtest.o
> obj-y += hw/
> obj-$(CONFIG_KVM) += kvm-all.o
> diff --git a/arch_init.c b/arch_init.c
> index 8daeafa..9943ed4 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -31,20 +31,15 @@
> #include "config.h"
> #include "monitor/monitor.h"
> #include "sysemu/sysemu.h"
> -#include "qemu/bitops.h"
> -#include "qemu/bitmap.h"
> #include "sysemu/arch_init.h"
> #include "audio/audio.h"
> #include "hw/pc.h"
> #include "hw/pci/pci.h"
> #include "hw/audiodev.h"
> #include "sysemu/kvm.h"
> -#include "migration/migration.h"
> #include "exec/gdbstub.h"
> #include "hw/smbios.h"
> -#include "exec/address-spaces.h"
> #include "hw/pcspk.h"
> -#include "migration/page_cache.h"
> #include "qemu/config-file.h"
> #include "qmp-commands.h"
> #include "trace.h"
> @@ -103,38 +98,6 @@ int graphic_depth = 15;
>
> const uint32_t arch_type = QEMU_ARCH;
>
> -/***********************************************************/
> -/* ram save/restore */
> -
> -#define RAM_SAVE_FLAG_FULL 0x01 /* Obsolete, not used anymore */
> -#define RAM_SAVE_FLAG_COMPRESS 0x02
> -#define RAM_SAVE_FLAG_MEM_SIZE 0x04
> -#define RAM_SAVE_FLAG_PAGE 0x08
> -#define RAM_SAVE_FLAG_EOS 0x10
> -#define RAM_SAVE_FLAG_CONTINUE 0x20
> -#define RAM_SAVE_FLAG_XBZRLE 0x40
> -
> -#ifdef __ALTIVEC__
> -#include <altivec.h>
> -#define VECTYPE vector unsigned char
> -#define SPLAT(p) vec_splat(vec_ld(0, p), 0)
> -#define ALL_EQ(v1, v2) vec_all_eq(v1, v2)
> -/* altivec.h may redefine the bool macro as vector type.
> - * Reset it to POSIX semantics. */
> -#undef bool
> -#define bool _Bool
> -#elif defined __SSE2__
> -#include <emmintrin.h>
> -#define VECTYPE __m128i
> -#define SPLAT(p) _mm_set1_epi8(*(p))
> -#define ALL_EQ(v1, v2) (_mm_movemask_epi8(_mm_cmpeq_epi8(v1, v2)) == 0xFFFF)
> -#else
> -#define VECTYPE unsigned long
> -#define SPLAT(p) (*(p) * (~0UL / 255))
> -#define ALL_EQ(v1, v2) ((v1) == (v2))
> -#endif
> -
> -
> static struct defconfig_file {
> const char *filename;
> /* Indicates it is an user config file (disabled by -no-user-config) */
> @@ -145,7 +108,6 @@ static struct defconfig_file {
> { NULL }, /* end of list */
> };
>
> -
> int qemu_read_default_config_files(bool userconfig)
> {
> int ret;
> @@ -164,726 +126,6 @@ int qemu_read_default_config_files(bool userconfig)
> return 0;
> }
>
> -static int is_dup_page(uint8_t *page)
> -{
> - VECTYPE *p = (VECTYPE *)page;
> - VECTYPE val = SPLAT(page);
> - int i;
> -
> - for (i = 0; i < TARGET_PAGE_SIZE / sizeof(VECTYPE); i++) {
> - if (!ALL_EQ(val, p[i])) {
> - return 0;
> - }
> - }
> -
> - return 1;
> -}
> -
> -/* struct contains XBZRLE cache and a static page
> - used by the compression */
> -static struct {
> - /* buffer used for XBZRLE encoding */
> - uint8_t *encoded_buf;
> - /* buffer for storing page content */
> - uint8_t *current_buf;
> - /* buffer used for XBZRLE decoding */
> - uint8_t *decoded_buf;
> - /* Cache for XBZRLE */
> - PageCache *cache;
> -} XBZRLE = {
> - .encoded_buf = NULL,
> - .current_buf = NULL,
> - .decoded_buf = NULL,
> - .cache = NULL,
> -};
> -
> -
> -int64_t xbzrle_cache_resize(int64_t new_size)
> -{
> - if (XBZRLE.cache != NULL) {
> - return cache_resize(XBZRLE.cache, new_size / TARGET_PAGE_SIZE) *
> - TARGET_PAGE_SIZE;
> - }
> - return pow2floor(new_size);
> -}
> -
> -/* accounting for migration statistics */
> -typedef struct AccountingInfo {
> - uint64_t dup_pages;
> - uint64_t norm_pages;
> - uint64_t iterations;
> - uint64_t xbzrle_bytes;
> - uint64_t xbzrle_pages;
> - uint64_t xbzrle_cache_miss;
> - uint64_t xbzrle_overflows;
> -} AccountingInfo;
> -
> -static AccountingInfo acct_info;
> -
> -static void acct_clear(void)
> -{
> - memset(&acct_info, 0, sizeof(acct_info));
> -}
> -
> -uint64_t dup_mig_bytes_transferred(void)
> -{
> - return acct_info.dup_pages * TARGET_PAGE_SIZE;
> -}
> -
> -uint64_t dup_mig_pages_transferred(void)
> -{
> - return acct_info.dup_pages;
> -}
> -
> -uint64_t norm_mig_bytes_transferred(void)
> -{
> - return acct_info.norm_pages * TARGET_PAGE_SIZE;
> -}
> -
> -uint64_t norm_mig_pages_transferred(void)
> -{
> - return acct_info.norm_pages;
> -}
> -
> -uint64_t xbzrle_mig_bytes_transferred(void)
> -{
> - return acct_info.xbzrle_bytes;
> -}
> -
> -uint64_t xbzrle_mig_pages_transferred(void)
> -{
> - return acct_info.xbzrle_pages;
> -}
> -
> -uint64_t xbzrle_mig_pages_cache_miss(void)
> -{
> - return acct_info.xbzrle_cache_miss;
> -}
> -
> -uint64_t xbzrle_mig_pages_overflow(void)
> -{
> - return acct_info.xbzrle_overflows;
> -}
> -
> -static size_t save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
> - int cont, int flag)
> -{
> - size_t size;
> -
> - qemu_put_be64(f, offset | cont | flag);
> - size = 8;
> -
> - if (!cont) {
> - 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;
> -}
> -
> -#define ENCODING_FLAG_XBZRLE 0x1
> -
> -static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
> - ram_addr_t current_addr, RAMBlock *block,
> - ram_addr_t offset, int cont, bool last_stage)
> -{
> - int encoded_len = 0, bytes_sent = -1;
> - uint8_t *prev_cached_page;
> -
> - if (!cache_is_cached(XBZRLE.cache, current_addr)) {
> - if (!last_stage) {
> - cache_insert(XBZRLE.cache, current_addr,
> - g_memdup(current_data, TARGET_PAGE_SIZE));
> - }
> - acct_info.xbzrle_cache_miss++;
> - return -1;
> - }
> -
> - prev_cached_page = get_cached_data(XBZRLE.cache, current_addr);
> -
> - /* save current buffer into memory */
> - memcpy(XBZRLE.current_buf, current_data, TARGET_PAGE_SIZE);
> -
> - /* XBZRLE encoding (if there is no overflow) */
> - encoded_len = xbzrle_encode_buffer(prev_cached_page, XBZRLE.current_buf,
> - TARGET_PAGE_SIZE, XBZRLE.encoded_buf,
> - TARGET_PAGE_SIZE);
> - if (encoded_len == 0) {
> - DPRINTF("Skipping unmodified page\n");
> - return 0;
> - } else if (encoded_len == -1) {
> - DPRINTF("Overflow\n");
> - acct_info.xbzrle_overflows++;
> - /* update data in the cache */
> - memcpy(prev_cached_page, current_data, TARGET_PAGE_SIZE);
> - return -1;
> - }
> -
> - /* we need to update the data in the cache, in order to get the same
> data */
> - if (!last_stage) {
> - memcpy(prev_cached_page, XBZRLE.current_buf, TARGET_PAGE_SIZE);
> - }
> -
> - /* Send XBZRLE based compressed page */
> - bytes_sent = save_block_hdr(f, block, offset, cont,
> RAM_SAVE_FLAG_XBZRLE);
> - qemu_put_byte(f, ENCODING_FLAG_XBZRLE);
> - qemu_put_be16(f, encoded_len);
> - qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len);
> - bytes_sent += encoded_len + 1 + 2;
> - acct_info.xbzrle_pages++;
> - acct_info.xbzrle_bytes += bytes_sent;
> -
> - return bytes_sent;
> -}
> -
> -
> -/* 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 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);
> - unsigned long size = base + (int128_get64(mr->size) >> TARGET_PAGE_BITS);
> -
> - unsigned long 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 inline bool migration_bitmap_set_dirty(MemoryRegion *mr,
> - ram_addr_t offset)
> -{
> - bool ret;
> - int nr = (mr->ram_addr + offset) >> TARGET_PAGE_BITS;
> -
> - ret = test_and_set_bit(nr, migration_bitmap);
> -
> - if (!ret) {
> - migration_dirty_pages++;
> - }
> - return ret;
> -}
> -
> -static void migration_bitmap_sync(void)
> -{
> - RAMBlock *block;
> - ram_addr_t addr;
> - uint64_t num_dirty_pages_init = migration_dirty_pages;
> - MigrationState *s = migrate_get_current();
> - static int64_t start_time;
> - static int64_t num_dirty_pages_period;
> - int64_t end_time;
> -
> - if (!start_time) {
> - start_time = qemu_get_clock_ms(rt_clock);
> - }
> -
> - trace_migration_bitmap_sync_start();
> - memory_global_sync_dirty_bitmap(get_system_memory());
> -
> - QTAILQ_FOREACH(block, &ram_list.blocks, next) {
> - for (addr = 0; addr < block->length; addr += TARGET_PAGE_SIZE) {
> - if (memory_region_test_and_clear_dirty(block->mr,
> - addr, TARGET_PAGE_SIZE,
> - DIRTY_MEMORY_MIGRATION)) {
> - migration_bitmap_set_dirty(block->mr, addr);
> - }
> - }
> - }
> - trace_migration_bitmap_sync_end(migration_dirty_pages
> - - num_dirty_pages_init);
> - num_dirty_pages_period += migration_dirty_pages - num_dirty_pages_init;
> - end_time = qemu_get_clock_ms(rt_clock);
> -
> - /* more than 1 second = 1000 millisecons */
> - if (end_time > start_time + 1000) {
> - s->dirty_pages_rate = num_dirty_pages_period * 1000
> - / (end_time - start_time);
> - s->dirty_bytes_rate = s->dirty_pages_rate * TARGET_PAGE_SIZE;
> - start_time = end_time;
> - num_dirty_pages_period = 0;
> - }
> -}
> -
> -/*
> - * ram_save_block: Writes a page of memory to the stream f
> - *
> - * Returns: The number of bytes written.
> - * 0 means no dirty pages
> - */
> -
> -static int ram_save_block(QEMUFile *f, bool last_stage)
> -{
> - RAMBlock *block = last_seen_block;
> - ram_addr_t offset = last_offset;
> - bool complete_round = false;
> - int bytes_sent = 0;
> - MemoryRegion *mr;
> - ram_addr_t current_addr;
> -
> - if (!block)
> - block = QTAILQ_FIRST(&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->length) {
> - offset = 0;
> - block = QTAILQ_NEXT(block, next);
> - if (!block) {
> - block = QTAILQ_FIRST(&ram_list.blocks);
> - complete_round = true;
> - }
> - } else {
> - uint8_t *p;
> - int cont = (block == last_sent_block) ?
> - RAM_SAVE_FLAG_CONTINUE : 0;
> -
> - p = memory_region_get_ram_ptr(mr) + offset;
> -
> - /* In doubt sent page as normal */
> - bytes_sent = -1;
> - if (is_dup_page(p)) {
> - acct_info.dup_pages++;
> - bytes_sent = save_block_hdr(f, block, offset, cont,
> - RAM_SAVE_FLAG_COMPRESS);
> - qemu_put_byte(f, *p);
> - bytes_sent += 1;
> - } else if (migrate_use_xbzrle()) {
> - current_addr = block->offset + offset;
> - bytes_sent = save_xbzrle_page(f, p, current_addr, block,
> - offset, cont, last_stage);
> - if (!last_stage) {
> - p = get_cached_data(XBZRLE.cache, current_addr);
> - }
> - }
> -
> - /* XBZRLE overflow or normal page */
> - if (bytes_sent == -1) {
> - bytes_sent = save_block_hdr(f, block, offset, cont,
> RAM_SAVE_FLAG_PAGE);
> - qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
> - bytes_sent += TARGET_PAGE_SIZE;
> - acct_info.norm_pages++;
> - }
> -
> - /* if page is unmodified, continue to the next */
> - if (bytes_sent > 0) {
> - last_sent_block = block;
> - break;
> - }
> - }
> - }
> - last_seen_block = block;
> - last_offset = offset;
> -
> - return bytes_sent;
> -}
> -
> -static uint64_t bytes_transferred;
> -
> -static ram_addr_t ram_save_remaining(void)
> -{
> - return migration_dirty_pages;
> -}
> -
> -uint64_t ram_bytes_remaining(void)
> -{
> - return ram_save_remaining() * TARGET_PAGE_SIZE;
> -}
> -
> -uint64_t ram_bytes_transferred(void)
> -{
> - return bytes_transferred;
> -}
> -
> -uint64_t ram_bytes_total(void)
> -{
> - RAMBlock *block;
> - uint64_t total = 0;
> -
> - QTAILQ_FOREACH(block, &ram_list.blocks, next)
> - total += block->length;
> -
> - return total;
> -}
> -
> -static void migration_end(void)
> -{
> - if (migration_bitmap) {
> - memory_global_dirty_log_stop();
> - g_free(migration_bitmap);
> - migration_bitmap = NULL;
> - }
> -
> - if (XBZRLE.cache) {
> - cache_fini(XBZRLE.cache);
> - g_free(XBZRLE.cache);
> - g_free(XBZRLE.encoded_buf);
> - g_free(XBZRLE.current_buf);
> - g_free(XBZRLE.decoded_buf);
> - XBZRLE.cache = NULL;
> - }
> -}
> -
> -static void ram_migration_cancel(void *opaque)
> -{
> - migration_end();
> -}
> -
> -static void reset_ram_globals(void)
> -{
> - last_seen_block = NULL;
> - last_sent_block = NULL;
> - last_offset = 0;
> - last_version = ram_list.version;
> -}
> -
> -#define MAX_WAIT 50 /* ms, half buffered_file limit */
> -
> -static int ram_save_setup(QEMUFile *f, void *opaque)
> -{
> - RAMBlock *block;
> - int64_t ram_pages = last_ram_offset() >> TARGET_PAGE_BITS;
> -
> - migration_bitmap = bitmap_new(ram_pages);
> - bitmap_set(migration_bitmap, 0, ram_pages);
> - migration_dirty_pages = ram_pages;
> -
> - qemu_mutex_lock_ramlist();
> - bytes_transferred = 0;
> - reset_ram_globals();
> -
> - if (migrate_use_xbzrle()) {
> - XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
> - TARGET_PAGE_SIZE,
> - TARGET_PAGE_SIZE);
> - if (!XBZRLE.cache) {
> - DPRINTF("Error creating cache\n");
> - return -1;
> - }
> - XBZRLE.encoded_buf = g_malloc0(TARGET_PAGE_SIZE);
> - XBZRLE.current_buf = g_malloc(TARGET_PAGE_SIZE);
> - acct_clear();
> - }
> -
> - memory_global_dirty_log_start();
> - migration_bitmap_sync();
> -
> - qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
> -
> - QTAILQ_FOREACH(block, &ram_list.blocks, next) {
> - qemu_put_byte(f, strlen(block->idstr));
> - qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
> - qemu_put_be64(f, block->length);
> - }
> -
> - qemu_mutex_unlock_ramlist();
> - qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
> -
> - return 0;
> -}
> -
> -static int ram_save_iterate(QEMUFile *f, void *opaque)
> -{
> - int ret;
> - int i;
> - int64_t t0;
> - int total_sent = 0;
> -
> - qemu_mutex_lock_ramlist();
> -
> - if (ram_list.version != last_version) {
> - reset_ram_globals();
> - }
> -
> - t0 = qemu_get_clock_ns(rt_clock);
> - i = 0;
> - while ((ret = qemu_file_rate_limit(f)) == 0) {
> - int bytes_sent;
> -
> - bytes_sent = ram_save_block(f, false);
> - /* no more blocks to sent */
> - if (bytes_sent == 0) {
> - break;
> - }
> - total_sent += bytes_sent;
> - acct_info.iterations++;
> - /* we want to check in the 1st loop, just in case it was the 1st time
> - and we had to sync the dirty bitmap.
> - qemu_get_clock_ns() is a bit expensive, so we only check each some
> - iterations
> - */
> - if ((i & 63) == 0) {
> - uint64_t t1 = (qemu_get_clock_ns(rt_clock) - t0) / 1000000;
> - if (t1 > MAX_WAIT) {
> - DPRINTF("big wait: %" PRIu64 " milliseconds, %d
> iterations\n",
> - t1, i);
> - break;
> - }
> - }
> - i++;
> - }
> -
> - qemu_mutex_unlock_ramlist();
> -
> - if (ret < 0) {
> - bytes_transferred += total_sent;
> - return ret;
> - }
> -
> - qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
> - total_sent += 8;
> - bytes_transferred += total_sent;
> -
> - return total_sent;
> -}
> -
> -static int ram_save_complete(QEMUFile *f, void *opaque)
> -{
> - qemu_mutex_lock_ramlist();
> - migration_bitmap_sync();
> -
> - /* try transferring iterative blocks of memory */
> -
> - /* flush all remaining blocks regardless of rate limiting */
> - while (true) {
> - int bytes_sent;
> -
> - bytes_sent = ram_save_block(f, true);
> - /* no more blocks to sent */
> - if (bytes_sent == 0) {
> - break;
> - }
> - bytes_transferred += bytes_sent;
> - }
> - migration_end();
> -
> - qemu_mutex_unlock_ramlist();
> - qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
> -
> - return 0;
> -}
> -
> -static 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) {
> - migration_bitmap_sync();
> - remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
> - }
> - return remaining_size;
> -}
> -
> -static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
> -{
> - int ret, rc = 0;
> - unsigned int xh_len;
> - int xh_flags;
> -
> - if (!XBZRLE.decoded_buf) {
> - XBZRLE.decoded_buf = g_malloc(TARGET_PAGE_SIZE);
> - }
> -
> - /* extract RLE header */
> - xh_flags = qemu_get_byte(f);
> - xh_len = qemu_get_be16(f);
> -
> - if (xh_flags != ENCODING_FLAG_XBZRLE) {
> - fprintf(stderr, "Failed to load XBZRLE page - wrong compression!\n");
> - return -1;
> - }
> -
> - if (xh_len > TARGET_PAGE_SIZE) {
> - fprintf(stderr, "Failed to load XBZRLE page - len overflow!\n");
> - return -1;
> - }
> - /* load data and decode */
> - qemu_get_buffer(f, XBZRLE.decoded_buf, xh_len);
> -
> - /* decode RLE */
> - ret = xbzrle_decode_buffer(XBZRLE.decoded_buf, xh_len, host,
> - TARGET_PAGE_SIZE);
> - if (ret == -1) {
> - fprintf(stderr, "Failed to load XBZRLE page - decode error!\n");
> - rc = -1;
> - } else if (ret > TARGET_PAGE_SIZE) {
> - fprintf(stderr, "Failed to load XBZRLE page - size %d exceeds %d!\n",
> - ret, TARGET_PAGE_SIZE);
> - abort();
> - }
> -
> - return rc;
> -}
> -
> -static inline void *host_from_stream_offset(QEMUFile *f,
> - ram_addr_t offset,
> - int flags)
> -{
> - static RAMBlock *block = NULL;
> - char id[256];
> - uint8_t len;
> -
> - if (flags & RAM_SAVE_FLAG_CONTINUE) {
> - if (!block) {
> - fprintf(stderr, "Ack, bad migration stream!\n");
> - return NULL;
> - }
> -
> - return memory_region_get_ram_ptr(block->mr) + offset;
> - }
> -
> - len = qemu_get_byte(f);
> - qemu_get_buffer(f, (uint8_t *)id, len);
> - id[len] = 0;
> -
> - QTAILQ_FOREACH(block, &ram_list.blocks, next) {
> - if (!strncmp(id, block->idstr, sizeof(id)))
> - return memory_region_get_ram_ptr(block->mr) + offset;
> - }
> -
> - fprintf(stderr, "Can't find block %s!\n", id);
> - return NULL;
> -}
> -
> -static int ram_load(QEMUFile *f, void *opaque, int version_id)
> -{
> - ram_addr_t addr;
> - int flags, ret = 0;
> - int error;
> - static uint64_t seq_iter;
> -
> - seq_iter++;
> -
> - if (version_id < 4 || version_id > 4) {
> - return -EINVAL;
> - }
> -
> - do {
> - addr = qemu_get_be64(f);
> -
> - flags = addr & ~TARGET_PAGE_MASK;
> - addr &= TARGET_PAGE_MASK;
> -
> - if (flags & RAM_SAVE_FLAG_MEM_SIZE) {
> - if (version_id == 4) {
> - /* Synchronize RAM block list */
> - char id[256];
> - ram_addr_t length;
> - ram_addr_t total_ram_bytes = addr;
> -
> - while (total_ram_bytes) {
> - RAMBlock *block;
> - uint8_t len;
> -
> - len = qemu_get_byte(f);
> - qemu_get_buffer(f, (uint8_t *)id, len);
> - id[len] = 0;
> - length = qemu_get_be64(f);
> -
> - QTAILQ_FOREACH(block, &ram_list.blocks, next) {
> - if (!strncmp(id, block->idstr, sizeof(id))) {
> - if (block->length != length) {
> - ret = -EINVAL;
> - goto done;
> - }
> - break;
> - }
> - }
> -
> - if (!block) {
> - fprintf(stderr, "Unknown ramblock \"%s\", cannot "
> - "accept migration\n", id);
> - ret = -EINVAL;
> - goto done;
> - }
> -
> - total_ram_bytes -= length;
> - }
> - }
> - }
> -
> - if (flags & RAM_SAVE_FLAG_COMPRESS) {
> - void *host;
> - uint8_t ch;
> -
> - host = host_from_stream_offset(f, addr, flags);
> - if (!host) {
> - return -EINVAL;
> - }
> -
> - ch = qemu_get_byte(f);
> - memset(host, ch, TARGET_PAGE_SIZE);
> -#ifndef _WIN32
> - if (ch == 0 &&
> - (!kvm_enabled() || kvm_has_sync_mmu()) &&
> - getpagesize() <= TARGET_PAGE_SIZE) {
> - qemu_madvise(host, TARGET_PAGE_SIZE, QEMU_MADV_DONTNEED);
> - }
> -#endif
> - } else if (flags & RAM_SAVE_FLAG_PAGE) {
> - void *host;
> -
> - host = host_from_stream_offset(f, addr, flags);
> - if (!host) {
> - return -EINVAL;
> - }
> -
> - qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
> - } else if (flags & RAM_SAVE_FLAG_XBZRLE) {
> - void *host = host_from_stream_offset(f, addr, flags);
> - if (!host) {
> - return -EINVAL;
> - }
> -
> - if (load_xbzrle(f, addr, host) < 0) {
> - ret = -EINVAL;
> - goto done;
> - }
> - }
> - error = qemu_file_get_error(f);
> - if (error) {
> - ret = error;
> - goto done;
> - }
> - } while (!(flags & RAM_SAVE_FLAG_EOS));
> -
> -done:
> - DPRINTF("Completed load of VM with exit code %d seq iteration "
> - "%" PRIu64 "\n", ret, seq_iter);
> - return ret;
> -}
> -
> -SaveVMHandlers savevm_ram_handlers = {
> - .save_live_setup = ram_save_setup,
> - .save_live_iterate = ram_save_iterate,
> - .save_live_complete = ram_save_complete,
> - .save_live_pending = ram_save_pending,
> - .load_state = ram_load,
> - .cancel = ram_migration_cancel,
> -};
> -
> #ifdef HAS_AUDIO
> struct soundhw {
> const char *name;
> diff --git a/migration-ram.c b/migration-ram.c
> new file mode 100644
> index 0000000..f5132b7
> --- /dev/null
> +++ b/migration-ram.c
> @@ -0,0 +1,799 @@
> +/*
> + * RAM Migration support
> + *
> + * Copyright (c) 2003-2008 Fabrice Bellard
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> copy
> + * of this software and associated documentation files (the "Software"), to
> deal
> + * in the Software without restriction, including without limitation the
> rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +#include <stdint.h>
> +#include <stdarg.h>
> +#include <stdlib.h>
> +#ifndef _WIN32
> +#include <sys/types.h>
> +#include <sys/mman.h>
> +#endif
> +#include "sysemu/sysemu.h"
> +#include "qemu/bitops.h"
> +#include "qemu/bitmap.h"
> +#include "sysemu/kvm.h"
> +#include "migration/migration.h"
> +#include "exec/address-spaces.h"
> +#include "migration/page_cache.h"
> +#include "migration/qemu-file.h"
> +#include "trace.h"
> +#include "exec/cpu-all.h"
> +
> +#ifdef DEBUG_ARCH_INIT
> +#define DPRINTF(fmt, ...) \
> + do { fprintf(stdout, "arch_init: " fmt, ## __VA_ARGS__); } while (0)
> +#else
> +#define DPRINTF(fmt, ...) \
> + do { } while (0)
> +#endif
> +
> +/***********************************************************/
> +/* ram save/restore */
> +
> +#define RAM_SAVE_FLAG_FULL 0x01 /* Obsolete, not used anymore */
> +#define RAM_SAVE_FLAG_COMPRESS 0x02
> +#define RAM_SAVE_FLAG_MEM_SIZE 0x04
> +#define RAM_SAVE_FLAG_PAGE 0x08
> +#define RAM_SAVE_FLAG_EOS 0x10
> +#define RAM_SAVE_FLAG_CONTINUE 0x20
> +#define RAM_SAVE_FLAG_XBZRLE 0x40
> +
> +#ifdef __ALTIVEC__
> +#include <altivec.h>
> +#define VECTYPE vector unsigned char
> +#define SPLAT(p) vec_splat(vec_ld(0, p), 0)
> +#define ALL_EQ(v1, v2) vec_all_eq(v1, v2)
> +/* altivec.h may redefine the bool macro as vector type.
> + * Reset it to POSIX semantics. */
> +#undef bool
> +#define bool _Bool
> +#elif defined __SSE2__
> +#include <emmintrin.h>
> +#define VECTYPE __m128i
> +#define SPLAT(p) _mm_set1_epi8(*(p))
> +#define ALL_EQ(v1, v2) (_mm_movemask_epi8(_mm_cmpeq_epi8(v1, v2)) == 0xFFFF)
> +#else
> +#define VECTYPE unsigned long
> +#define SPLAT(p) (*(p) * (~0UL / 255))
> +#define ALL_EQ(v1, v2) ((v1) == (v2))
> +#endif
> +
> +static int is_dup_page(uint8_t *page)
> +{
> + VECTYPE *p = (VECTYPE *)page;
> + VECTYPE val = SPLAT(page);
> + int i;
> +
> + for (i = 0; i < TARGET_PAGE_SIZE / sizeof(VECTYPE); i++) {
> + if (!ALL_EQ(val, p[i])) {
> + return 0;
> + }
> + }
> +
> + return 1;
> +}
> +
> +/* struct contains XBZRLE cache and a static page
> + used by the compression */
> +static struct {
> + /* buffer used for XBZRLE encoding */
> + uint8_t *encoded_buf;
> + /* buffer for storing page content */
> + uint8_t *current_buf;
> + /* buffer used for XBZRLE decoding */
> + uint8_t *decoded_buf;
> + /* Cache for XBZRLE */
> + PageCache *cache;
> +} XBZRLE = {
> + .encoded_buf = NULL,
> + .current_buf = NULL,
> + .decoded_buf = NULL,
> + .cache = NULL,
> +};
> +
> +
> +int64_t xbzrle_cache_resize(int64_t new_size)
> +{
> + if (XBZRLE.cache != NULL) {
> + return cache_resize(XBZRLE.cache, new_size / TARGET_PAGE_SIZE) *
> + TARGET_PAGE_SIZE;
> + }
> + return pow2floor(new_size);
> +}
> +
> +/* accounting for migration statistics */
> +typedef struct AccountingInfo {
> + uint64_t dup_pages;
> + uint64_t norm_pages;
> + uint64_t iterations;
> + uint64_t xbzrle_bytes;
> + uint64_t xbzrle_pages;
> + uint64_t xbzrle_cache_miss;
> + uint64_t xbzrle_overflows;
> +} AccountingInfo;
> +
> +static AccountingInfo acct_info;
> +
> +static void acct_clear(void)
> +{
> + memset(&acct_info, 0, sizeof(acct_info));
> +}
> +
> +uint64_t dup_mig_bytes_transferred(void)
> +{
> + return acct_info.dup_pages * TARGET_PAGE_SIZE;
> +}
> +
> +uint64_t dup_mig_pages_transferred(void)
> +{
> + return acct_info.dup_pages;
> +}
> +
> +uint64_t norm_mig_bytes_transferred(void)
> +{
> + return acct_info.norm_pages * TARGET_PAGE_SIZE;
> +}
> +
> +uint64_t norm_mig_pages_transferred(void)
> +{
> + return acct_info.norm_pages;
> +}
> +
> +uint64_t xbzrle_mig_bytes_transferred(void)
> +{
> + return acct_info.xbzrle_bytes;
> +}
> +
> +uint64_t xbzrle_mig_pages_transferred(void)
> +{
> + return acct_info.xbzrle_pages;
> +}
> +
> +uint64_t xbzrle_mig_pages_cache_miss(void)
> +{
> + return acct_info.xbzrle_cache_miss;
> +}
> +
> +uint64_t xbzrle_mig_pages_overflow(void)
> +{
> + return acct_info.xbzrle_overflows;
> +}
> +
> +static size_t save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,
> + int cont, int flag)
> +{
> + size_t size;
> +
> + qemu_put_be64(f, offset | cont | flag);
> + size = 8;
> +
> + if (!cont) {
> + 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;
> +}
> +
> +#define ENCODING_FLAG_XBZRLE 0x1
> +
> +static int save_xbzrle_page(QEMUFile *f, uint8_t *current_data,
> + ram_addr_t current_addr, RAMBlock *block,
> + ram_addr_t offset, int cont, bool last_stage)
> +{
> + int encoded_len = 0, bytes_sent = -1;
> + uint8_t *prev_cached_page;
> +
> + if (!cache_is_cached(XBZRLE.cache, current_addr)) {
> + if (!last_stage) {
> + cache_insert(XBZRLE.cache, current_addr,
> + g_memdup(current_data, TARGET_PAGE_SIZE));
> + }
> + acct_info.xbzrle_cache_miss++;
> + return -1;
> + }
> +
> + prev_cached_page = get_cached_data(XBZRLE.cache, current_addr);
> +
> + /* save current buffer into memory */
> + memcpy(XBZRLE.current_buf, current_data, TARGET_PAGE_SIZE);
> +
> + /* XBZRLE encoding (if there is no overflow) */
> + encoded_len = xbzrle_encode_buffer(prev_cached_page, XBZRLE.current_buf,
> + TARGET_PAGE_SIZE, XBZRLE.encoded_buf,
> + TARGET_PAGE_SIZE);
> + if (encoded_len == 0) {
> + DPRINTF("Skipping unmodified page\n");
> + return 0;
> + } else if (encoded_len == -1) {
> + DPRINTF("Overflow\n");
> + acct_info.xbzrle_overflows++;
> + /* update data in the cache */
> + memcpy(prev_cached_page, current_data, TARGET_PAGE_SIZE);
> + return -1;
> + }
> +
> + /* we need to update the data in the cache, in order to get the same
> data */
> + if (!last_stage) {
> + memcpy(prev_cached_page, XBZRLE.current_buf, TARGET_PAGE_SIZE);
> + }
> +
> + /* Send XBZRLE based compressed page */
> + bytes_sent = save_block_hdr(f, block, offset, cont,
> RAM_SAVE_FLAG_XBZRLE);
> + qemu_put_byte(f, ENCODING_FLAG_XBZRLE);
> + qemu_put_be16(f, encoded_len);
> + qemu_put_buffer(f, XBZRLE.encoded_buf, encoded_len);
> + bytes_sent += encoded_len + 1 + 2;
> + acct_info.xbzrle_pages++;
> + acct_info.xbzrle_bytes += bytes_sent;
> +
> + return bytes_sent;
> +}
> +
> +
> +/* 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 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);
> + unsigned long size = base + (int128_get64(mr->size) >> TARGET_PAGE_BITS);
> +
> + unsigned long 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 inline bool migration_bitmap_set_dirty(MemoryRegion *mr,
> + ram_addr_t offset)
> +{
> + bool ret;
> + int nr = (mr->ram_addr + offset) >> TARGET_PAGE_BITS;
> +
> + ret = test_and_set_bit(nr, migration_bitmap);
> +
> + if (!ret) {
> + migration_dirty_pages++;
> + }
> + return ret;
> +}
> +
> +static void migration_bitmap_sync(void)
> +{
> + RAMBlock *block;
> + ram_addr_t addr;
> + uint64_t num_dirty_pages_init = migration_dirty_pages;
> + MigrationState *s = migrate_get_current();
> + static int64_t start_time;
> + static int64_t num_dirty_pages_period;
> + int64_t end_time;
> +
> + if (!start_time) {
> + start_time = qemu_get_clock_ms(rt_clock);
> + }
> +
> + trace_migration_bitmap_sync_start();
> + memory_global_sync_dirty_bitmap(get_system_memory());
> +
> + QTAILQ_FOREACH(block, &ram_list.blocks, next) {
> + for (addr = 0; addr < block->length; addr += TARGET_PAGE_SIZE) {
> + if (memory_region_test_and_clear_dirty(block->mr,
> + addr, TARGET_PAGE_SIZE,
> + DIRTY_MEMORY_MIGRATION)) {
> + migration_bitmap_set_dirty(block->mr, addr);
> + }
> + }
> + }
> + trace_migration_bitmap_sync_end(migration_dirty_pages
> + - num_dirty_pages_init);
> + num_dirty_pages_period += migration_dirty_pages - num_dirty_pages_init;
> + end_time = qemu_get_clock_ms(rt_clock);
> +
> + /* more than 1 second = 1000 millisecons */
> + if (end_time > start_time + 1000) {
> + s->dirty_pages_rate = num_dirty_pages_period * 1000
> + / (end_time - start_time);
> + s->dirty_bytes_rate = s->dirty_pages_rate * TARGET_PAGE_SIZE;
> + start_time = end_time;
> + num_dirty_pages_period = 0;
> + }
> +}
> +
> +/*
> + * ram_save_block: Writes a page of memory to the stream f
> + *
> + * Returns: The number of bytes written.
> + * 0 means no dirty pages
> + */
> +
> +static int ram_save_block(QEMUFile *f, bool last_stage)
> +{
> + RAMBlock *block = last_seen_block;
> + ram_addr_t offset = last_offset;
> + bool complete_round = false;
> + int bytes_sent = 0;
> + MemoryRegion *mr;
> + ram_addr_t current_addr;
> +
> + if (!block)
> + block = QTAILQ_FIRST(&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->length) {
> + offset = 0;
> + block = QTAILQ_NEXT(block, next);
> + if (!block) {
> + block = QTAILQ_FIRST(&ram_list.blocks);
> + complete_round = true;
> + }
> + } else {
> + uint8_t *p;
> + int cont = (block == last_sent_block) ?
> + RAM_SAVE_FLAG_CONTINUE : 0;
> +
> + p = memory_region_get_ram_ptr(mr) + offset;
> +
> + /* In doubt sent page as normal */
> + bytes_sent = -1;
> + if (is_dup_page(p)) {
> + acct_info.dup_pages++;
> + bytes_sent = save_block_hdr(f, block, offset, cont,
> + RAM_SAVE_FLAG_COMPRESS);
> + qemu_put_byte(f, *p);
> + bytes_sent += 1;
> + } else if (migrate_use_xbzrle()) {
> + current_addr = block->offset + offset;
> + bytes_sent = save_xbzrle_page(f, p, current_addr, block,
> + offset, cont, last_stage);
> + if (!last_stage) {
> + p = get_cached_data(XBZRLE.cache, current_addr);
> + }
> + }
> +
> + /* XBZRLE overflow or normal page */
> + if (bytes_sent == -1) {
> + bytes_sent = save_block_hdr(f, block, offset, cont,
> RAM_SAVE_FLAG_PAGE);
> + qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
> + bytes_sent += TARGET_PAGE_SIZE;
> + acct_info.norm_pages++;
> + }
> +
> + /* if page is unmodified, continue to the next */
> + if (bytes_sent > 0) {
> + last_sent_block = block;
> + break;
> + }
> + }
> + }
> + last_seen_block = block;
> + last_offset = offset;
> +
> + return bytes_sent;
> +}
> +
> +static uint64_t bytes_transferred;
> +
> +static ram_addr_t ram_save_remaining(void)
> +{
> + return migration_dirty_pages;
> +}
> +
> +uint64_t ram_bytes_remaining(void)
> +{
> + return ram_save_remaining() * TARGET_PAGE_SIZE;
> +}
> +
> +uint64_t ram_bytes_transferred(void)
> +{
> + return bytes_transferred;
> +}
> +
> +uint64_t ram_bytes_total(void)
> +{
> + RAMBlock *block;
> + uint64_t total = 0;
> +
> + QTAILQ_FOREACH(block, &ram_list.blocks, next)
> + total += block->length;
> +
> + return total;
> +}
> +
> +static void migration_end(void)
> +{
> + if (migration_bitmap) {
> + memory_global_dirty_log_stop();
> + g_free(migration_bitmap);
> + migration_bitmap = NULL;
> + }
> +
> + if (XBZRLE.cache) {
> + cache_fini(XBZRLE.cache);
> + g_free(XBZRLE.cache);
> + g_free(XBZRLE.encoded_buf);
> + g_free(XBZRLE.current_buf);
> + g_free(XBZRLE.decoded_buf);
> + XBZRLE.cache = NULL;
> + }
> +}
> +
> +static void ram_migration_cancel(void *opaque)
> +{
> + migration_end();
> +}
> +
> +static void reset_ram_globals(void)
> +{
> + last_seen_block = NULL;
> + last_sent_block = NULL;
> + last_offset = 0;
> + last_version = ram_list.version;
> +}
> +
> +#define MAX_WAIT 50 /* ms, half buffered_file limit */
> +
> +static int ram_save_setup(QEMUFile *f, void *opaque)
> +{
> + RAMBlock *block;
> + int64_t ram_pages = last_ram_offset() >> TARGET_PAGE_BITS;
> +
> + migration_bitmap = bitmap_new(ram_pages);
> + bitmap_set(migration_bitmap, 0, ram_pages);
> + migration_dirty_pages = ram_pages;
> +
> + qemu_mutex_lock_ramlist();
> + bytes_transferred = 0;
> + reset_ram_globals();
> +
> + if (migrate_use_xbzrle()) {
> + XBZRLE.cache = cache_init(migrate_xbzrle_cache_size() /
> + TARGET_PAGE_SIZE,
> + TARGET_PAGE_SIZE);
> + if (!XBZRLE.cache) {
> + DPRINTF("Error creating cache\n");
> + return -1;
> + }
> + XBZRLE.encoded_buf = g_malloc0(TARGET_PAGE_SIZE);
> + XBZRLE.current_buf = g_malloc(TARGET_PAGE_SIZE);
> + acct_clear();
> + }
> +
> + memory_global_dirty_log_start();
> + migration_bitmap_sync();
> +
> + qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
> +
> + QTAILQ_FOREACH(block, &ram_list.blocks, next) {
> + qemu_put_byte(f, strlen(block->idstr));
> + qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
> + qemu_put_be64(f, block->length);
> + }
> +
> + qemu_mutex_unlock_ramlist();
> + qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
> +
> + return 0;
> +}
> +
> +static int ram_save_iterate(QEMUFile *f, void *opaque)
> +{
> + int ret;
> + int i;
> + int64_t t0;
> + int total_sent = 0;
> +
> + qemu_mutex_lock_ramlist();
> +
> + if (ram_list.version != last_version) {
> + reset_ram_globals();
> + }
> +
> + t0 = qemu_get_clock_ns(rt_clock);
> + i = 0;
> + while ((ret = qemu_file_rate_limit(f)) == 0) {
> + int bytes_sent;
> +
> + bytes_sent = ram_save_block(f, false);
> + /* no more blocks to sent */
> + if (bytes_sent == 0) {
> + break;
> + }
> + total_sent += bytes_sent;
> + acct_info.iterations++;
> + /* we want to check in the 1st loop, just in case it was the 1st time
> + and we had to sync the dirty bitmap.
> + qemu_get_clock_ns() is a bit expensive, so we only check each some
> + iterations
> + */
> + if ((i & 63) == 0) {
> + uint64_t t1 = (qemu_get_clock_ns(rt_clock) - t0) / 1000000;
> + if (t1 > MAX_WAIT) {
> + DPRINTF("big wait: %" PRIu64 " milliseconds, %d
> iterations\n",
> + t1, i);
> + break;
> + }
> + }
> + i++;
> + }
> +
> + qemu_mutex_unlock_ramlist();
> +
> + if (ret < 0) {
> + bytes_transferred += total_sent;
> + return ret;
> + }
> +
> + qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
> + total_sent += 8;
> + bytes_transferred += total_sent;
> +
> + return total_sent;
> +}
> +
> +static int ram_save_complete(QEMUFile *f, void *opaque)
> +{
> + qemu_mutex_lock_ramlist();
> + migration_bitmap_sync();
> +
> + /* try transferring iterative blocks of memory */
> +
> + /* flush all remaining blocks regardless of rate limiting */
> + while (true) {
> + int bytes_sent;
> +
> + bytes_sent = ram_save_block(f, true);
> + /* no more blocks to sent */
> + if (bytes_sent == 0) {
> + break;
> + }
> + bytes_transferred += bytes_sent;
> + }
> + migration_end();
> +
> + qemu_mutex_unlock_ramlist();
> + qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
> +
> + return 0;
> +}
> +
> +static 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) {
> + migration_bitmap_sync();
> + remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
> + }
> + return remaining_size;
> +}
> +
> +static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
> +{
> + int ret, rc = 0;
> + unsigned int xh_len;
> + int xh_flags;
> +
> + if (!XBZRLE.decoded_buf) {
> + XBZRLE.decoded_buf = g_malloc(TARGET_PAGE_SIZE);
> + }
> +
> + /* extract RLE header */
> + xh_flags = qemu_get_byte(f);
> + xh_len = qemu_get_be16(f);
> +
> + if (xh_flags != ENCODING_FLAG_XBZRLE) {
> + fprintf(stderr, "Failed to load XBZRLE page - wrong compression!\n");
> + return -1;
> + }
> +
> + if (xh_len > TARGET_PAGE_SIZE) {
> + fprintf(stderr, "Failed to load XBZRLE page - len overflow!\n");
> + return -1;
> + }
> + /* load data and decode */
> + qemu_get_buffer(f, XBZRLE.decoded_buf, xh_len);
> +
> + /* decode RLE */
> + ret = xbzrle_decode_buffer(XBZRLE.decoded_buf, xh_len, host,
> + TARGET_PAGE_SIZE);
> + if (ret == -1) {
> + fprintf(stderr, "Failed to load XBZRLE page - decode error!\n");
> + rc = -1;
> + } else if (ret > TARGET_PAGE_SIZE) {
> + fprintf(stderr, "Failed to load XBZRLE page - size %d exceeds %d!\n",
> + ret, TARGET_PAGE_SIZE);
> + abort();
> + }
> +
> + return rc;
> +}
> +
> +static inline void *host_from_stream_offset(QEMUFile *f,
> + ram_addr_t offset,
> + int flags)
> +{
> + static RAMBlock *block = NULL;
> + char id[256];
> + uint8_t len;
> +
> + if (flags & RAM_SAVE_FLAG_CONTINUE) {
> + if (!block) {
> + fprintf(stderr, "Ack, bad migration stream!\n");
> + return NULL;
> + }
> +
> + return memory_region_get_ram_ptr(block->mr) + offset;
> + }
> +
> + len = qemu_get_byte(f);
> + qemu_get_buffer(f, (uint8_t *)id, len);
> + id[len] = 0;
> +
> + QTAILQ_FOREACH(block, &ram_list.blocks, next) {
> + if (!strncmp(id, block->idstr, sizeof(id)))
> + return memory_region_get_ram_ptr(block->mr) + offset;
> + }
> +
> + fprintf(stderr, "Can't find block %s!\n", id);
> + return NULL;
> +}
> +
> +static int ram_load(QEMUFile *f, void *opaque, int version_id)
> +{
> + ram_addr_t addr;
> + int flags, ret = 0;
> + int error;
> + static uint64_t seq_iter;
> +
> + seq_iter++;
> +
> + if (version_id < 4 || version_id > 4) {
> + return -EINVAL;
> + }
> +
> + do {
> + addr = qemu_get_be64(f);
> +
> + flags = addr & ~TARGET_PAGE_MASK;
> + addr &= TARGET_PAGE_MASK;
> +
> + if (flags & RAM_SAVE_FLAG_MEM_SIZE) {
> + if (version_id == 4) {
> + /* Synchronize RAM block list */
> + char id[256];
> + ram_addr_t length;
> + ram_addr_t total_ram_bytes = addr;
> +
> + while (total_ram_bytes) {
> + RAMBlock *block;
> + uint8_t len;
> +
> + len = qemu_get_byte(f);
> + qemu_get_buffer(f, (uint8_t *)id, len);
> + id[len] = 0;
> + length = qemu_get_be64(f);
> +
> + QTAILQ_FOREACH(block, &ram_list.blocks, next) {
> + if (!strncmp(id, block->idstr, sizeof(id))) {
> + if (block->length != length) {
> + ret = -EINVAL;
> + goto done;
> + }
> + break;
> + }
> + }
> +
> + if (!block) {
> + fprintf(stderr, "Unknown ramblock \"%s\", cannot "
> + "accept migration\n", id);
> + ret = -EINVAL;
> + goto done;
> + }
> +
> + total_ram_bytes -= length;
> + }
> + }
> + }
> +
> + if (flags & RAM_SAVE_FLAG_COMPRESS) {
> + void *host;
> + uint8_t ch;
> +
> + host = host_from_stream_offset(f, addr, flags);
> + if (!host) {
> + return -EINVAL;
> + }
> +
> + ch = qemu_get_byte(f);
> + memset(host, ch, TARGET_PAGE_SIZE);
> +#ifndef _WIN32
> + if (ch == 0 &&
> + (!kvm_enabled() || kvm_has_sync_mmu()) &&
> + getpagesize() <= TARGET_PAGE_SIZE) {
> + qemu_madvise(host, TARGET_PAGE_SIZE, QEMU_MADV_DONTNEED);
> + }
> +#endif
> + } else if (flags & RAM_SAVE_FLAG_PAGE) {
> + void *host;
> +
> + host = host_from_stream_offset(f, addr, flags);
> + if (!host) {
> + return -EINVAL;
> + }
> +
> + qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
> + } else if (flags & RAM_SAVE_FLAG_XBZRLE) {
> + void *host = host_from_stream_offset(f, addr, flags);
> + if (!host) {
> + return -EINVAL;
> + }
> +
> + if (load_xbzrle(f, addr, host) < 0) {
> + ret = -EINVAL;
> + goto done;
> + }
> + }
> + error = qemu_file_get_error(f);
> + if (error) {
> + ret = error;
> + goto done;
> + }
> + } while (!(flags & RAM_SAVE_FLAG_EOS));
> +
> +done:
> + DPRINTF("Completed load of VM with exit code %d seq iteration "
> + "%" PRIu64 "\n", ret, seq_iter);
> + return ret;
> +}
> +
> +SaveVMHandlers savevm_ram_handlers = {
> + .save_live_setup = ram_save_setup,
> + .save_live_iterate = ram_save_iterate,
> + .save_live_complete = ram_save_complete,
> + .save_live_pending = ram_save_pending,
> + .load_state = ram_load,
> + .cancel = ram_migration_cancel,
> +};
>