| /* | 
 |  * QEMU System Emulator | 
 |  * | 
 |  * Copyright (c) 2003-2008 Fabrice Bellard | 
 |  * | 
 |  * Permission is hereby granted, free of charge, to any person obtaining a copy | 
 |  * of this software and associated documentation files (the "Software"), to deal | 
 |  * in the Software without restriction, including without limitation the rights | 
 |  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | 
 |  * copies of the Software, and to permit persons to whom the Software is | 
 |  * furnished to do so, subject to the following conditions: | 
 |  * | 
 |  * The above copyright notice and this permission notice shall be included in | 
 |  * all copies or substantial portions of the Software. | 
 |  * | 
 |  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | 
 |  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | 
 |  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | 
 |  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | 
 |  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | 
 |  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | 
 |  * THE SOFTWARE. | 
 |  */ | 
 | #include <stdint.h> | 
 | #include <stdarg.h> | 
 | #include <stdlib.h> | 
 | #ifndef _WIN32 | 
 | #include <sys/types.h> | 
 | #include <sys/mman.h> | 
 | #endif | 
 | #include "config.h" | 
 | #include "monitor/monitor.h" | 
 | #include "sysemu/sysemu.h" | 
 | #include "qemu/bitops.h" | 
 | #include "qemu/bitmap.h" | 
 | #include "sysemu/arch_init.h" | 
 | #include "audio/audio.h" | 
 | #include "hw/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 "qmp-commands.h" | 
 | #include "trace.h" | 
 | #include "exec/cpu-all.h" | 
 | #include "hw/acpi/acpi.h" | 
 |  | 
 | #ifdef DEBUG_ARCH_INIT | 
 | #define DPRINTF(fmt, ...) \ | 
 |     do { fprintf(stdout, "arch_init: " fmt, ## __VA_ARGS__); } while (0) | 
 | #else | 
 | #define DPRINTF(fmt, ...) \ | 
 |     do { } while (0) | 
 | #endif | 
 |  | 
 | #ifdef TARGET_SPARC | 
 | int graphic_width = 1024; | 
 | int graphic_height = 768; | 
 | int graphic_depth = 8; | 
 | #else | 
 | int graphic_width = 800; | 
 | int graphic_height = 600; | 
 | int graphic_depth = 32; | 
 | #endif | 
 |  | 
 |  | 
 | #if defined(TARGET_ALPHA) | 
 | #define QEMU_ARCH QEMU_ARCH_ALPHA | 
 | #elif defined(TARGET_ARM) | 
 | #define QEMU_ARCH QEMU_ARCH_ARM | 
 | #elif defined(TARGET_CRIS) | 
 | #define QEMU_ARCH QEMU_ARCH_CRIS | 
 | #elif defined(TARGET_I386) | 
 | #define QEMU_ARCH QEMU_ARCH_I386 | 
 | #elif defined(TARGET_M68K) | 
 | #define QEMU_ARCH QEMU_ARCH_M68K | 
 | #elif defined(TARGET_LM32) | 
 | #define QEMU_ARCH QEMU_ARCH_LM32 | 
 | #elif defined(TARGET_MICROBLAZE) | 
 | #define QEMU_ARCH QEMU_ARCH_MICROBLAZE | 
 | #elif defined(TARGET_MIPS) | 
 | #define QEMU_ARCH QEMU_ARCH_MIPS | 
 | #elif defined(TARGET_MOXIE) | 
 | #define QEMU_ARCH QEMU_ARCH_MOXIE | 
 | #elif defined(TARGET_OPENRISC) | 
 | #define QEMU_ARCH QEMU_ARCH_OPENRISC | 
 | #elif defined(TARGET_PPC) | 
 | #define QEMU_ARCH QEMU_ARCH_PPC | 
 | #elif defined(TARGET_S390X) | 
 | #define QEMU_ARCH QEMU_ARCH_S390X | 
 | #elif defined(TARGET_SH4) | 
 | #define QEMU_ARCH QEMU_ARCH_SH4 | 
 | #elif defined(TARGET_SPARC) | 
 | #define QEMU_ARCH QEMU_ARCH_SPARC | 
 | #elif defined(TARGET_XTENSA) | 
 | #define QEMU_ARCH QEMU_ARCH_XTENSA | 
 | #elif defined(TARGET_UNICORE32) | 
 | #define QEMU_ARCH QEMU_ARCH_UNICORE32 | 
 | #endif | 
 |  | 
 | const uint32_t arch_type = QEMU_ARCH; | 
 | static bool mig_throttle_on; | 
 | static int dirty_rate_high_cnt; | 
 | static void check_guest_throttling(void); | 
 |  | 
 | /***********************************************************/ | 
 | /* 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 */ | 
 |  | 
 |  | 
 | static struct defconfig_file { | 
 |     const char *filename; | 
 |     /* Indicates it is an user config file (disabled by -no-user-config) */ | 
 |     bool userconfig; | 
 | } default_config_files[] = { | 
 |     { CONFIG_QEMU_CONFDIR "/qemu.conf",                   true }, | 
 |     { CONFIG_QEMU_CONFDIR "/target-" TARGET_NAME ".conf", true }, | 
 |     { NULL }, /* end of list */ | 
 | }; | 
 |  | 
 |  | 
 | int qemu_read_default_config_files(bool userconfig) | 
 | { | 
 |     int ret; | 
 |     struct defconfig_file *f; | 
 |  | 
 |     for (f = default_config_files; f->filename; f++) { | 
 |         if (!userconfig && f->userconfig) { | 
 |             continue; | 
 |         } | 
 |         ret = qemu_read_config_file(f->filename); | 
 |         if (ret < 0 && ret != -ENOENT) { | 
 |             return ret; | 
 |         } | 
 |     } | 
 |  | 
 |     return 0; | 
 | } | 
 |  | 
 | static 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; | 
 |     /* 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 skipped_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 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; | 
 | } | 
 |  | 
 | 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, current_data); | 
 |         } | 
 |         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 bool ram_bulk_stage; | 
 |  | 
 | 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 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; | 
 | } | 
 |  | 
 | /* Needs iothread lock! */ | 
 |  | 
 | 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 bytes_xfer_prev; | 
 |     static int64_t num_dirty_pages_period; | 
 |     int64_t end_time; | 
 |     int64_t bytes_xfer_now; | 
 |  | 
 |     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); | 
 |  | 
 |     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_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; | 
 |         } | 
 |         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; | 
 |                 ram_bulk_stage = false; | 
 |             } | 
 |         } else { | 
 |             int ret; | 
 |             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; | 
 |             ret = ram_control_save_page(f, block->offset, | 
 |                                offset, TARGET_PAGE_SIZE, &bytes_sent); | 
 |  | 
 |             if (ret != RAM_SAVE_CONTROL_NOT_SUPP) { | 
 |                 if (ret != RAM_SAVE_CONTROL_DELAYED) { | 
 |                     if (bytes_sent > 0) { | 
 |                         acct_info.norm_pages++; | 
 |                     } else if (bytes_sent == 0) { | 
 |                         acct_info.dup_pages++; | 
 |                     } | 
 |                 } | 
 |             } else if (is_zero_range(p, TARGET_PAGE_SIZE)) { | 
 |                 acct_info.dup_pages++; | 
 |                 bytes_sent = save_block_hdr(f, block, offset, cont, | 
 |                                             RAM_SAVE_FLAG_COMPRESS); | 
 |                 qemu_put_byte(f, 0); | 
 |                 bytes_sent++; | 
 |             } else if (!ram_bulk_stage && 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_async(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; | 
 |  | 
 | 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; | 
 |  | 
 |     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; | 
 |     ram_bulk_stage = true; | 
 | } | 
 |  | 
 | #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; | 
 |     mig_throttle_on = false; | 
 |     dirty_rate_high_cnt = 0; | 
 |  | 
 |     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(); | 
 |     } | 
 |  | 
 |     qemu_mutex_lock_iothread(); | 
 |     qemu_mutex_lock_ramlist(); | 
 |     bytes_transferred = 0; | 
 |     reset_ram_globals(); | 
 |  | 
 |     memory_global_dirty_log_start(); | 
 |     migration_bitmap_sync(); | 
 |     qemu_mutex_unlock_iothread(); | 
 |  | 
 |     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(); | 
 |  | 
 |     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 total_sent = 0; | 
 |  | 
 |     qemu_mutex_lock_ramlist(); | 
 |  | 
 |     if (ram_list.version != last_version) { | 
 |         reset_ram_globals(); | 
 |     } | 
 |  | 
 |     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 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++; | 
 |         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++; | 
 |     } | 
 |  | 
 |     qemu_mutex_unlock_ramlist(); | 
 |  | 
 |     /* | 
 |      * Must occur before EOS (or any QEMUFile operation) | 
 |      * because of RDMA protocol. | 
 |      */ | 
 |     ram_control_after_iterate(f, RAM_CONTROL_ROUND); | 
 |  | 
 |     bytes_transferred += total_sent; | 
 |  | 
 |     /* | 
 |      * Do not count these 8 bytes into total_sent, so that we can | 
 |      * return 0 if no page had been dirtied. | 
 |      */ | 
 |     qemu_put_be64(f, RAM_SAVE_FLAG_EOS); | 
 |     bytes_transferred += 8; | 
 |  | 
 |     ret = qemu_file_get_error(f); | 
 |     if (ret < 0) { | 
 |         return ret; | 
 |     } | 
 |  | 
 |     return total_sent; | 
 | } | 
 |  | 
 | static int ram_save_complete(QEMUFile *f, void *opaque) | 
 | { | 
 |     qemu_mutex_lock_ramlist(); | 
 |     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 bytes_sent; | 
 |  | 
 |         bytes_sent = ram_save_block(f, true); | 
 |         /* no more blocks to sent */ | 
 |         if (bytes_sent == 0) { | 
 |             break; | 
 |         } | 
 |         bytes_transferred += bytes_sent; | 
 |     } | 
 |  | 
 |     ram_control_after_iterate(f, RAM_CONTROL_FINISH); | 
 |     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) { | 
 |         qemu_mutex_lock_iothread(); | 
 |         migration_bitmap_sync(); | 
 |         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) | 
 | { | 
 |     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; | 
 | } | 
 |  | 
 | /* | 
 |  * 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 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) { | 
 |                                 fprintf(stderr, | 
 |                                         "Length mismatch: %s: " RAM_ADDR_FMT | 
 |                                         " in != " RAM_ADDR_FMT "\n", id, length, | 
 |                                         block->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); | 
 |             ram_handle_compressed(host, ch, TARGET_PAGE_SIZE); | 
 |         } 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; | 
 |             } | 
 |         } else if (flags & RAM_SAVE_FLAG_HOOK) { | 
 |             ram_control_load_hook(f, flags); | 
 |         } | 
 |         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, | 
 | }; | 
 |  | 
 | struct soundhw { | 
 |     const char *name; | 
 |     const char *descr; | 
 |     int enabled; | 
 |     int isa; | 
 |     union { | 
 |         int (*init_isa) (ISABus *bus); | 
 |         int (*init_pci) (PCIBus *bus); | 
 |     } init; | 
 | }; | 
 |  | 
 | static struct soundhw soundhw[9]; | 
 | static int soundhw_count; | 
 |  | 
 | void isa_register_soundhw(const char *name, const char *descr, | 
 |                           int (*init_isa)(ISABus *bus)) | 
 | { | 
 |     assert(soundhw_count < ARRAY_SIZE(soundhw) - 1); | 
 |     soundhw[soundhw_count].name = name; | 
 |     soundhw[soundhw_count].descr = descr; | 
 |     soundhw[soundhw_count].isa = 1; | 
 |     soundhw[soundhw_count].init.init_isa = init_isa; | 
 |     soundhw_count++; | 
 | } | 
 |  | 
 | void pci_register_soundhw(const char *name, const char *descr, | 
 |                           int (*init_pci)(PCIBus *bus)) | 
 | { | 
 |     assert(soundhw_count < ARRAY_SIZE(soundhw) - 1); | 
 |     soundhw[soundhw_count].name = name; | 
 |     soundhw[soundhw_count].descr = descr; | 
 |     soundhw[soundhw_count].isa = 0; | 
 |     soundhw[soundhw_count].init.init_pci = init_pci; | 
 |     soundhw_count++; | 
 | } | 
 |  | 
 | void select_soundhw(const char *optarg) | 
 | { | 
 |     struct soundhw *c; | 
 |  | 
 |     if (is_help_option(optarg)) { | 
 |     show_valid_cards: | 
 |  | 
 |         if (soundhw_count) { | 
 |              printf("Valid sound card names (comma separated):\n"); | 
 |              for (c = soundhw; c->name; ++c) { | 
 |                  printf ("%-11s %s\n", c->name, c->descr); | 
 |              } | 
 |              printf("\n-soundhw all will enable all of the above\n"); | 
 |         } else { | 
 |              printf("Machine has no user-selectable audio hardware " | 
 |                     "(it may or may not have always-present audio hardware).\n"); | 
 |         } | 
 |         exit(!is_help_option(optarg)); | 
 |     } | 
 |     else { | 
 |         size_t l; | 
 |         const char *p; | 
 |         char *e; | 
 |         int bad_card = 0; | 
 |  | 
 |         if (!strcmp(optarg, "all")) { | 
 |             for (c = soundhw; c->name; ++c) { | 
 |                 c->enabled = 1; | 
 |             } | 
 |             return; | 
 |         } | 
 |  | 
 |         p = optarg; | 
 |         while (*p) { | 
 |             e = strchr(p, ','); | 
 |             l = !e ? strlen(p) : (size_t) (e - p); | 
 |  | 
 |             for (c = soundhw; c->name; ++c) { | 
 |                 if (!strncmp(c->name, p, l) && !c->name[l]) { | 
 |                     c->enabled = 1; | 
 |                     break; | 
 |                 } | 
 |             } | 
 |  | 
 |             if (!c->name) { | 
 |                 if (l > 80) { | 
 |                     fprintf(stderr, | 
 |                             "Unknown sound card name (too big to show)\n"); | 
 |                 } | 
 |                 else { | 
 |                     fprintf(stderr, "Unknown sound card name `%.*s'\n", | 
 |                             (int) l, p); | 
 |                 } | 
 |                 bad_card = 1; | 
 |             } | 
 |             p += l + (e != NULL); | 
 |         } | 
 |  | 
 |         if (bad_card) { | 
 |             goto show_valid_cards; | 
 |         } | 
 |     } | 
 | } | 
 |  | 
 | void audio_init(void) | 
 | { | 
 |     struct soundhw *c; | 
 |     ISABus *isa_bus = (ISABus *) object_resolve_path_type("", TYPE_ISA_BUS, NULL); | 
 |     PCIBus *pci_bus = (PCIBus *) object_resolve_path_type("", TYPE_PCI_BUS, NULL); | 
 |  | 
 |     for (c = soundhw; c->name; ++c) { | 
 |         if (c->enabled) { | 
 |             if (c->isa) { | 
 |                 if (!isa_bus) { | 
 |                     fprintf(stderr, "ISA bus not available for %s\n", c->name); | 
 |                     exit(1); | 
 |                 } | 
 |                 c->init.init_isa(isa_bus); | 
 |             } else { | 
 |                 if (!pci_bus) { | 
 |                     fprintf(stderr, "PCI bus not available for %s\n", c->name); | 
 |                     exit(1); | 
 |                 } | 
 |                 c->init.init_pci(pci_bus); | 
 |             } | 
 |         } | 
 |     } | 
 | } | 
 |  | 
 | int qemu_uuid_parse(const char *str, uint8_t *uuid) | 
 | { | 
 |     int ret; | 
 |  | 
 |     if (strlen(str) != 36) { | 
 |         return -1; | 
 |     } | 
 |  | 
 |     ret = sscanf(str, UUID_FMT, &uuid[0], &uuid[1], &uuid[2], &uuid[3], | 
 |                  &uuid[4], &uuid[5], &uuid[6], &uuid[7], &uuid[8], &uuid[9], | 
 |                  &uuid[10], &uuid[11], &uuid[12], &uuid[13], &uuid[14], | 
 |                  &uuid[15]); | 
 |  | 
 |     if (ret != 16) { | 
 |         return -1; | 
 |     } | 
 |     return 0; | 
 | } | 
 |  | 
 | void do_acpitable_option(const QemuOpts *opts) | 
 | { | 
 | #ifdef TARGET_I386 | 
 |     Error *err = NULL; | 
 |  | 
 |     acpi_table_add(opts, &err); | 
 |     if (err) { | 
 |         error_report("Wrong acpi table provided: %s", | 
 |                      error_get_pretty(err)); | 
 |         error_free(err); | 
 |         exit(1); | 
 |     } | 
 | #endif | 
 | } | 
 |  | 
 | void do_smbios_option(QemuOpts *opts) | 
 | { | 
 | #ifdef TARGET_I386 | 
 |     smbios_entry_add(opts); | 
 | #endif | 
 | } | 
 |  | 
 | void cpudef_init(void) | 
 | { | 
 | #if defined(cpudef_setup) | 
 |     cpudef_setup(); /* parse cpu definitions in target config file */ | 
 | #endif | 
 | } | 
 |  | 
 | int tcg_available(void) | 
 | { | 
 |     return 1; | 
 | } | 
 |  | 
 | int kvm_available(void) | 
 | { | 
 | #ifdef CONFIG_KVM | 
 |     return 1; | 
 | #else | 
 |     return 0; | 
 | #endif | 
 | } | 
 |  | 
 | int xen_available(void) | 
 | { | 
 | #ifdef CONFIG_XEN | 
 |     return 1; | 
 | #else | 
 |     return 0; | 
 | #endif | 
 | } | 
 |  | 
 |  | 
 | TargetInfo *qmp_query_target(Error **errp) | 
 | { | 
 |     TargetInfo *info = g_malloc0(sizeof(*info)); | 
 |  | 
 |     info->arch = g_strdup(TARGET_NAME); | 
 |  | 
 |     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; | 
 |     } | 
 | } |