]> Git Repo - qemu.git/blobdiff - migration/ram.c
migration: fix migrate_cancel leads live_migration thread endless loop
[qemu.git] / migration / ram.c
index cd7a446c95afac0f01a1cab8d924ba0f84503a33..52a2d498e4d40e7ae5c061dc37fb95e2cb141269 100644 (file)
@@ -159,18 +159,44 @@ out:
     return ret;
 }
 
+static bool ramblock_is_ignored(RAMBlock *block)
+{
+    return !qemu_ram_is_migratable(block) ||
+           (migrate_ignore_shared() && qemu_ram_is_shared(block));
+}
+
 /* Should be holding either ram_list.mutex, or the RCU lock. */
+#define RAMBLOCK_FOREACH_NOT_IGNORED(block)            \
+    INTERNAL_RAMBLOCK_FOREACH(block)                   \
+        if (ramblock_is_ignored(block)) {} else
+
 #define RAMBLOCK_FOREACH_MIGRATABLE(block)             \
     INTERNAL_RAMBLOCK_FOREACH(block)                   \
         if (!qemu_ram_is_migratable(block)) {} else
 
 #undef RAMBLOCK_FOREACH
 
+int foreach_not_ignored_block(RAMBlockIterFunc func, void *opaque)
+{
+    RAMBlock *block;
+    int ret = 0;
+
+    rcu_read_lock();
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
+        ret = func(block, opaque);
+        if (ret) {
+            break;
+        }
+    }
+    rcu_read_unlock();
+    return ret;
+}
+
 static void ramblock_recv_map_init(void)
 {
     RAMBlock *rb;
 
-    RAMBLOCK_FOREACH_MIGRATABLE(rb) {
+    RAMBLOCK_FOREACH_NOT_IGNORED(rb) {
         assert(!rb->receivedmap);
         rb->receivedmap = bitmap_new(rb->max_length >> qemu_target_page_bits());
     }
@@ -290,6 +316,8 @@ struct RAMState {
     uint32_t last_version;
     /* We are in the first round */
     bool ram_bulk_stage;
+    /* The free page optimization is enabled */
+    bool fpo_enabled;
     /* How many times we have dirty too many pages */
     int dirty_rate_high_cnt;
     /* these variables are used for bitmap sync */
@@ -316,18 +344,53 @@ struct RAMState {
     uint64_t target_page_count;
     /* number of dirty bits in the bitmap */
     uint64_t migration_dirty_pages;
-    /* protects modification of the bitmap */
+    /* Protects modification of the bitmap and migration dirty pages */
     QemuMutex bitmap_mutex;
     /* The RAMBlock used in the last src_page_requests */
     RAMBlock *last_req_rb;
     /* Queue of outstanding page requests from the destination */
     QemuMutex src_page_req_mutex;
-    QSIMPLEQ_HEAD(src_page_requests, RAMSrcPageRequest) src_page_requests;
+    QSIMPLEQ_HEAD(, RAMSrcPageRequest) src_page_requests;
 };
 typedef struct RAMState RAMState;
 
 static RAMState *ram_state;
 
+static NotifierWithReturnList precopy_notifier_list;
+
+void precopy_infrastructure_init(void)
+{
+    notifier_with_return_list_init(&precopy_notifier_list);
+}
+
+void precopy_add_notifier(NotifierWithReturn *n)
+{
+    notifier_with_return_list_add(&precopy_notifier_list, n);
+}
+
+void precopy_remove_notifier(NotifierWithReturn *n)
+{
+    notifier_with_return_remove(n);
+}
+
+int precopy_notify(PrecopyNotifyReason reason, Error **errp)
+{
+    PrecopyNotifyData pnd;
+    pnd.reason = reason;
+    pnd.errp = errp;
+
+    return notifier_with_return_list_notify(&precopy_notifier_list, &pnd);
+}
+
+void precopy_enable_free_page_optimization(void)
+{
+    if (!ram_state) {
+        return;
+    }
+
+    ram_state->fpo_enabled = true;
+}
+
 uint64_t ram_bytes_remaining(void)
 {
     return ram_state ? (ram_state->migration_dirty_pages * TARGET_PAGE_SIZE) :
@@ -520,20 +583,29 @@ exit:
 
 #define MULTIFD_FLAG_SYNC (1 << 0)
 
+/* This value needs to be a multiple of qemu_target_page_size() */
+#define MULTIFD_PACKET_SIZE (512 * 1024)
+
 typedef struct {
     uint32_t magic;
     uint32_t version;
     unsigned char uuid[16]; /* QemuUUID */
     uint8_t id;
+    uint8_t unused1[7];     /* Reserved for future use */
+    uint64_t unused2[4];    /* Reserved for future use */
 } __attribute__((packed)) MultiFDInit_t;
 
 typedef struct {
     uint32_t magic;
     uint32_t version;
     uint32_t flags;
-    uint32_t size;
-    uint32_t used;
+    /* maximum number of allocated pages */
+    uint32_t pages_alloc;
+    uint32_t pages_used;
+    /* size of the next packet that contains pages */
+    uint32_t next_packet_size;
     uint64_t packet_num;
+    uint64_t unused[4];    /* Reserved for future use */
     char ramblock[256];
     uint64_t offset[];
 } __attribute__((packed)) MultiFDPacket_t;
@@ -580,6 +652,8 @@ typedef struct {
     MultiFDPacket_t *packet;
     /* multifd flags for each packet */
     uint32_t flags;
+    /* size of the next packet that contains pages */
+    uint32_t next_packet_size;
     /* global number of generated multifd packets */
     uint64_t packet_num;
     /* thread local variables */
@@ -587,8 +661,6 @@ typedef struct {
     uint64_t num_packets;
     /* pages sent through this channel */
     uint64_t num_pages;
-    /* syncs main thread and channels */
-    QemuSemaphore sem_sync;
 }  MultiFDSendParams;
 
 typedef struct {
@@ -616,6 +688,8 @@ typedef struct {
     /* global number of generated multifd packets */
     uint64_t packet_num;
     /* thread local variables */
+    /* size of the next packet that contains pages */
+    uint32_t next_packet_size;
     /* packets sent through this channel */
     uint64_t num_packets;
     /* pages sent through this channel */
@@ -713,13 +787,15 @@ static void multifd_pages_clear(MultiFDPages_t *pages)
 static void multifd_send_fill_packet(MultiFDSendParams *p)
 {
     MultiFDPacket_t *packet = p->packet;
+    uint32_t page_max = MULTIFD_PACKET_SIZE / qemu_target_page_size();
     int i;
 
     packet->magic = cpu_to_be32(MULTIFD_MAGIC);
     packet->version = cpu_to_be32(MULTIFD_VERSION);
     packet->flags = cpu_to_be32(p->flags);
-    packet->size = cpu_to_be32(migrate_multifd_page_count());
-    packet->used = cpu_to_be32(p->pages->used);
+    packet->pages_alloc = cpu_to_be32(page_max);
+    packet->pages_used = cpu_to_be32(p->pages->used);
+    packet->next_packet_size = cpu_to_be32(p->next_packet_size);
     packet->packet_num = cpu_to_be64(p->packet_num);
 
     if (p->pages->block) {
@@ -734,6 +810,7 @@ static void multifd_send_fill_packet(MultiFDSendParams *p)
 static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
 {
     MultiFDPacket_t *packet = p->packet;
+    uint32_t pages_max = MULTIFD_PACKET_SIZE / qemu_target_page_size();
     RAMBlock *block;
     int i;
 
@@ -755,22 +832,35 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
 
     p->flags = be32_to_cpu(packet->flags);
 
-    packet->size = be32_to_cpu(packet->size);
-    if (packet->size > migrate_multifd_page_count()) {
+    packet->pages_alloc = be32_to_cpu(packet->pages_alloc);
+    /*
+     * If we recevied a packet that is 100 times bigger than expected
+     * just stop migration.  It is a magic number.
+     */
+    if (packet->pages_alloc > pages_max * 100) {
         error_setg(errp, "multifd: received packet "
-                   "with size %d and expected maximum size %d",
-                   packet->size, migrate_multifd_page_count()) ;
+                   "with size %d and expected a maximum size of %d",
+                   packet->pages_alloc, pages_max * 100) ;
         return -1;
     }
+    /*
+     * We received a packet that is bigger than expected but inside
+     * reasonable limits (see previous comment).  Just reallocate.
+     */
+    if (packet->pages_alloc > p->pages->allocated) {
+        multifd_pages_clear(p->pages);
+        p->pages = multifd_pages_init(packet->pages_alloc);
+    }
 
-    p->pages->used = be32_to_cpu(packet->used);
-    if (p->pages->used > packet->size) {
+    p->pages->used = be32_to_cpu(packet->pages_used);
+    if (p->pages->used > packet->pages_alloc) {
         error_setg(errp, "multifd: received packet "
-                   "with size %d and expected maximum size %d",
-                   p->pages->used, packet->size) ;
+                   "with %d pages and expected maximum pages are %d",
+                   p->pages->used, packet->pages_alloc) ;
         return -1;
     }
 
+    p->next_packet_size = be32_to_cpu(packet->next_packet_size);
     p->packet_num = be64_to_cpu(packet->packet_num);
 
     if (p->pages->used) {
@@ -802,8 +892,6 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
 
 struct {
     MultiFDSendParams *params;
-    /* number of created threads */
-    int count;
     /* array of pages to sent */
     MultiFDPages_t *pages;
     /* syncs main thread and channels */
@@ -825,14 +913,14 @@ struct {
  *    - to make easier to know what to free at the end of migration
  *
  * This way we always know who is the owner of each "pages" struct,
- * and we don't need any loocking.  It belongs to the migration thread
+ * and we don't need any locking.  It belongs to the migration thread
  * or to the channel thread.  Switching is safe because the migration
  * thread is using the channel mutex when changing it, and the channel
  * have to had finish with its own, otherwise pending_job can't be
  * false.
  */
 
-static void multifd_send_pages(void)
+static int multifd_send_pages(void)
 {
     int i;
     static int next_channel;
@@ -845,6 +933,11 @@ static void multifd_send_pages(void)
         p = &multifd_send_state->params[i];
 
         qemu_mutex_lock(&p->mutex);
+        if (p->quit) {
+            error_report("%s: channel %d has already quit!", __func__, i);
+            qemu_mutex_unlock(&p->mutex);
+            return -1;
+        }
         if (!p->pending_job) {
             p->pending_job++;
             next_channel = (i + 1) % migrate_multifd_channels();
@@ -863,9 +956,11 @@ static void multifd_send_pages(void)
     ram_counters.transferred += transferred;;
     qemu_mutex_unlock(&p->mutex);
     qemu_sem_post(&p->sem);
+
+    return 1;
 }
 
-static void multifd_queue_page(RAMBlock *block, ram_addr_t offset)
+static int multifd_queue_page(RAMBlock *block, ram_addr_t offset)
 {
     MultiFDPages_t *pages = multifd_send_state->pages;
 
@@ -880,15 +975,19 @@ static void multifd_queue_page(RAMBlock *block, ram_addr_t offset)
         pages->used++;
 
         if (pages->used < pages->allocated) {
-            return;
+            return 1;
         }
     }
 
-    multifd_send_pages();
+    if (multifd_send_pages() < 0) {
+        return -1;
+    }
 
     if (pages->block != block) {
-        multifd_queue_page(block, offset);
+        return  multifd_queue_page(block, offset);
     }
+
+    return 1;
 }
 
 static void multifd_send_terminate_threads(Error *err)
@@ -917,13 +1016,12 @@ static void multifd_send_terminate_threads(Error *err)
     }
 }
 
-int multifd_save_cleanup(Error **errp)
+void multifd_save_cleanup(void)
 {
     int i;
-    int ret = 0;
 
     if (!migrate_use_multifd()) {
-        return 0;
+        return;
     }
     multifd_send_terminate_threads(NULL);
     for (i = 0; i < migrate_multifd_channels(); i++) {
@@ -936,7 +1034,6 @@ int multifd_save_cleanup(Error **errp)
         p->c = NULL;
         qemu_mutex_destroy(&p->mutex);
         qemu_sem_destroy(&p->sem);
-        qemu_sem_destroy(&p->sem_sync);
         g_free(p->name);
         p->name = NULL;
         multifd_pages_clear(p->pages);
@@ -953,7 +1050,6 @@ int multifd_save_cleanup(Error **errp)
     multifd_send_state->pages = NULL;
     g_free(multifd_send_state);
     multifd_send_state = NULL;
-    return ret;
 }
 
 static void multifd_send_sync_main(void)
@@ -964,7 +1060,10 @@ static void multifd_send_sync_main(void)
         return;
     }
     if (multifd_send_state->pages->used) {
-        multifd_send_pages();
+        if (multifd_send_pages() < 0) {
+            error_report("%s: multifd_send_pages fail", __func__);
+            return;
+        }
     }
     for (i = 0; i < migrate_multifd_channels(); i++) {
         MultiFDSendParams *p = &multifd_send_state->params[i];
@@ -973,6 +1072,12 @@ static void multifd_send_sync_main(void)
 
         qemu_mutex_lock(&p->mutex);
 
+        if (p->quit) {
+            error_report("%s: channel %d has already quit", __func__, i);
+            qemu_mutex_unlock(&p->mutex);
+            return;
+        }
+
         p->packet_num = multifd_send_state->packet_num++;
         p->flags |= MULTIFD_FLAG_SYNC;
         p->pending_job++;
@@ -1012,6 +1117,7 @@ static void *multifd_send_thread(void *opaque)
             uint64_t packet_num = p->packet_num;
             uint32_t flags = p->flags;
 
+            p->next_packet_size = used * qemu_target_page_size();
             multifd_send_fill_packet(p);
             p->flags = 0;
             p->num_packets++;
@@ -1019,7 +1125,8 @@ static void *multifd_send_thread(void *opaque)
             p->pages->used = 0;
             qemu_mutex_unlock(&p->mutex);
 
-            trace_multifd_send(p->id, packet_num, used, flags);
+            trace_multifd_send(p->id, packet_num, used, flags,
+                               p->next_packet_size);
 
             ret = qio_channel_write_all(p->c, (void *)p->packet,
                                         p->packet_len, &local_err);
@@ -1027,9 +1134,12 @@ static void *multifd_send_thread(void *opaque)
                 break;
             }
 
-            ret = qio_channel_writev_all(p->c, p->pages->iov, used, &local_err);
-            if (ret != 0) {
-                break;
+            if (used) {
+                ret = qio_channel_writev_all(p->c, p->pages->iov,
+                                             used, &local_err);
+                if (ret != 0) {
+                    break;
+                }
             }
 
             qemu_mutex_lock(&p->mutex);
@@ -1071,24 +1181,21 @@ static void multifd_new_send_channel_async(QIOTask *task, gpointer opaque)
     Error *local_err = NULL;
 
     if (qio_task_propagate_error(task, &local_err)) {
-        if (multifd_save_cleanup(&local_err) != 0) {
-            migrate_set_error(migrate_get_current(), local_err);
-        }
+        migrate_set_error(migrate_get_current(), local_err);
+        multifd_save_cleanup();
     } else {
         p->c = QIO_CHANNEL(sioc);
         qio_channel_set_delay(p->c, false);
         p->running = true;
         qemu_thread_create(&p->thread, p->name, multifd_send_thread, p,
                            QEMU_THREAD_JOINABLE);
-
-        atomic_inc(&multifd_send_state->count);
     }
 }
 
 int multifd_save_setup(void)
 {
     int thread_count;
-    uint32_t page_count = migrate_multifd_page_count();
+    uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size();
     uint8_t i;
 
     if (!migrate_use_multifd()) {
@@ -1097,7 +1204,6 @@ int multifd_save_setup(void)
     thread_count = migrate_multifd_channels();
     multifd_send_state = g_malloc0(sizeof(*multifd_send_state));
     multifd_send_state->params = g_new0(MultiFDSendParams, thread_count);
-    atomic_set(&multifd_send_state->count, 0);
     multifd_send_state->pages = multifd_pages_init(page_count);
     qemu_sem_init(&multifd_send_state->sem_sync, 0);
     qemu_sem_init(&multifd_send_state->channels_ready, 0);
@@ -1107,7 +1213,6 @@ int multifd_save_setup(void)
 
         qemu_mutex_init(&p->mutex);
         qemu_sem_init(&p->sem, 0);
-        qemu_sem_init(&p->sem_sync, 0);
         p->quit = false;
         p->pending_job = 0;
         p->id = i;
@@ -1206,15 +1311,15 @@ static void multifd_recv_sync_main(void)
 
         trace_multifd_recv_sync_main_wait(p->id);
         qemu_sem_wait(&multifd_recv_state->sem_sync);
+    }
+    for (i = 0; i < migrate_multifd_channels(); i++) {
+        MultiFDRecvParams *p = &multifd_recv_state->params[i];
+
         qemu_mutex_lock(&p->mutex);
         if (multifd_recv_state->packet_num < p->packet_num) {
             multifd_recv_state->packet_num = p->packet_num;
         }
         qemu_mutex_unlock(&p->mutex);
-    }
-    for (i = 0; i < migrate_multifd_channels(); i++) {
-        MultiFDRecvParams *p = &multifd_recv_state->params[i];
-
         trace_multifd_recv_sync_main_signal(p->id);
         qemu_sem_post(&p->sem_sync);
     }
@@ -1252,14 +1357,18 @@ static void *multifd_recv_thread(void *opaque)
 
         used = p->pages->used;
         flags = p->flags;
-        trace_multifd_recv(p->id, p->packet_num, used, flags);
+        trace_multifd_recv(p->id, p->packet_num, used, flags,
+                           p->next_packet_size);
         p->num_packets++;
         p->num_pages += used;
         qemu_mutex_unlock(&p->mutex);
 
-        ret = qio_channel_readv_all(p->c, p->pages->iov, used, &local_err);
-        if (ret != 0) {
-            break;
+        if (used) {
+            ret = qio_channel_readv_all(p->c, p->pages->iov,
+                                        used, &local_err);
+            if (ret != 0) {
+                break;
+            }
         }
 
         if (flags & MULTIFD_FLAG_SYNC) {
@@ -1284,7 +1393,7 @@ static void *multifd_recv_thread(void *opaque)
 int multifd_load_setup(void)
 {
     int thread_count;
-    uint32_t page_count = migrate_multifd_page_count();
+    uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size();
     uint8_t i;
 
     if (!migrate_use_multifd()) {
@@ -1322,8 +1431,13 @@ bool multifd_recv_all_channels_created(void)
     return thread_count == atomic_read(&multifd_recv_state->count);
 }
 
-/* Return true if multifd is ready for the migration, otherwise false */
-bool multifd_recv_new_channel(QIOChannel *ioc)
+/*
+ * Try to receive all multifd channels to get ready for the migration.
+ * - Return true and do not set @errp when correctly receving all channels;
+ * - Return false and do not set @errp when correctly receiving the current one;
+ * - Return false and set @errp when failing to receive the current channel.
+ */
+bool multifd_recv_new_channel(QIOChannel *ioc, Error **errp)
 {
     MultiFDRecvParams *p;
     Error *local_err = NULL;
@@ -1332,6 +1446,10 @@ bool multifd_recv_new_channel(QIOChannel *ioc)
     id = multifd_recv_initial_packet(ioc, &local_err);
     if (id < 0) {
         multifd_recv_terminate_threads(local_err);
+        error_propagate_prepend(errp, local_err,
+                                "failed to receive packet"
+                                " via multifd channel %d: ",
+                                atomic_read(&multifd_recv_state->count));
         return false;
     }
 
@@ -1340,6 +1458,7 @@ bool multifd_recv_new_channel(QIOChannel *ioc)
         error_setg(&local_err, "multifd: received id '%d' already setup'",
                    id);
         multifd_recv_terminate_threads(local_err);
+        error_propagate(errp, local_err);
         return false;
     }
     p->c = ioc;
@@ -1351,7 +1470,8 @@ bool multifd_recv_new_channel(QIOChannel *ioc)
     qemu_thread_create(&p->thread, p->name, multifd_recv_thread, p,
                        QEMU_THREAD_JOINABLE);
     atomic_inc(&multifd_recv_state->count);
-    return multifd_recv_state->count == migrate_multifd_channels();
+    return atomic_read(&multifd_recv_state->count) ==
+           migrate_multifd_channels();
 }
 
 /**
@@ -1485,25 +1605,30 @@ static int save_xbzrle_page(RAMState *rs, uint8_t **current_data,
     encoded_len = xbzrle_encode_buffer(prev_cached_page, XBZRLE.current_buf,
                                        TARGET_PAGE_SIZE, XBZRLE.encoded_buf,
                                        TARGET_PAGE_SIZE);
+
+    /*
+     * Update the cache contents, so that it corresponds to the data
+     * sent, in all cases except where we skip the page.
+     */
+    if (!last_stage && encoded_len != 0) {
+        memcpy(prev_cached_page, XBZRLE.current_buf, TARGET_PAGE_SIZE);
+        /*
+         * In the case where we couldn't compress, ensure that the caller
+         * sends the data from the cache, since the guest might have
+         * changed the RAM since we copied it.
+         */
+        *current_data = prev_cached_page;
+    }
+
     if (encoded_len == 0) {
         trace_save_xbzrle_page_skipping();
         return 0;
     } else if (encoded_len == -1) {
         trace_save_xbzrle_page_overflow();
         xbzrle_counters.overflow++;
-        /* 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(rs, rs->f, block,
                                     offset | RAM_SAVE_FLAG_XBZRLE);
@@ -1521,9 +1646,7 @@ static int save_xbzrle_page(RAMState *rs, uint8_t **current_data,
 /**
  * migration_bitmap_find_dirty: find the next dirty page from start
  *
- * Called with rcu_read_lock() to protect migration_bitmap
- *
- * Returns the byte offset within memory region of the start of a dirty page
+ * Returns the page offset within memory region of the start of a dirty page
  *
  * @rs: current RAM state
  * @rb: RAMBlock where to search for dirty pages
@@ -1537,11 +1660,15 @@ unsigned long migration_bitmap_find_dirty(RAMState *rs, RAMBlock *rb,
     unsigned long *bitmap = rb->bmap;
     unsigned long next;
 
-    if (!qemu_ram_is_migratable(rb)) {
+    if (ramblock_is_ignored(rb)) {
         return size;
     }
 
-    if (rs->ram_bulk_stage && start > 0) {
+    /*
+     * When the free page optimization is enabled, we need to check the bitmap
+     * to send the non-free pages rather than all the pages in the bulk stage.
+     */
+    if (!rs->fpo_enabled && rs->ram_bulk_stage && start > 0) {
         next = start + 1;
     } else {
         next = find_next_bit(bitmap, size, start);
@@ -1556,19 +1683,50 @@ static inline bool migration_bitmap_clear_dirty(RAMState *rs,
 {
     bool ret;
 
+    qemu_mutex_lock(&rs->bitmap_mutex);
+
+    /*
+     * Clear dirty bitmap if needed.  This _must_ be called before we
+     * send any of the page in the chunk because we need to make sure
+     * we can capture further page content changes when we sync dirty
+     * log the next time.  So as long as we are going to send any of
+     * the page in the chunk we clear the remote dirty bitmap for all.
+     * Clearing it earlier won't be a problem, but too late will.
+     */
+    if (rb->clear_bmap && clear_bmap_test_and_clear(rb, page)) {
+        uint8_t shift = rb->clear_bmap_shift;
+        hwaddr size = 1ULL << (TARGET_PAGE_BITS + shift);
+        hwaddr start = (page << TARGET_PAGE_BITS) & (-size);
+
+        /*
+         * CLEAR_BITMAP_SHIFT_MIN should always guarantee this... this
+         * can make things easier sometimes since then start address
+         * of the small chunk will always be 64 pages aligned so the
+         * bitmap will always be aligned to unsigned long.  We should
+         * even be able to remove this restriction but I'm simply
+         * keeping it.
+         */
+        assert(shift >= 6);
+        trace_migration_bitmap_clear_dirty(rb->idstr, start, size, page);
+        memory_region_clear_dirty_bitmap(rb->mr, start, size);
+    }
+
     ret = test_and_clear_bit(page, rb->bmap);
 
     if (ret) {
         rs->migration_dirty_pages--;
     }
+    qemu_mutex_unlock(&rs->bitmap_mutex);
+
     return ret;
 }
 
+/* Called with RCU critical section */
 static void migration_bitmap_sync_range(RAMState *rs, RAMBlock *rb,
-                                        ram_addr_t start, ram_addr_t length)
+                                        ram_addr_t length)
 {
     rs->migration_dirty_pages +=
-        cpu_physical_memory_sync_dirty_bitmap(rb, start, length,
+        cpu_physical_memory_sync_dirty_bitmap(rb, 0, length,
                                               &rs->num_dirty_pages_period);
 }
 
@@ -1586,13 +1744,19 @@ uint64_t ram_pagesize_summary(void)
     RAMBlock *block;
     uint64_t summary = 0;
 
-    RAMBLOCK_FOREACH_MIGRATABLE(block) {
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
         summary |= block->page_size;
     }
 
     return summary;
 }
 
+uint64_t ram_get_total_transferred_pages(void)
+{
+    return  ram_counters.normal + ram_counters.duplicate +
+                compression_counters.pages + xbzrle_counters.pages;
+}
+
 static void migration_update_rates(RAMState *rs, int64_t end_time)
 {
     uint64_t page_count = rs->target_page_count - rs->target_page_count_prev;
@@ -1650,8 +1814,8 @@ static void migration_bitmap_sync(RAMState *rs)
 
     qemu_mutex_lock(&rs->bitmap_mutex);
     rcu_read_lock();
-    RAMBLOCK_FOREACH_MIGRATABLE(block) {
-        migration_bitmap_sync_range(rs, block, 0, block->used_length);
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
+        migration_bitmap_sync_range(rs, block, block->used_length);
     }
     ram_counters.remaining = ram_bytes_remaining();
     rcu_read_unlock();
@@ -1698,6 +1862,25 @@ static void migration_bitmap_sync(RAMState *rs)
     }
 }
 
+static void migration_bitmap_sync_precopy(RAMState *rs)
+{
+    Error *local_err = NULL;
+
+    /*
+     * The current notifier usage is just an optimization to migration, so we
+     * don't stop the normal migration process in the error case.
+     */
+    if (precopy_notify(PRECOPY_NOTIFY_BEFORE_BITMAP_SYNC, &local_err)) {
+        error_report_err(local_err);
+    }
+
+    migration_bitmap_sync(rs);
+
+    if (precopy_notify(PRECOPY_NOTIFY_AFTER_BITMAP_SYNC, &local_err)) {
+        error_report_err(local_err);
+    }
+}
+
 /**
  * save_zero_page_to_file: send the zero page to the file
  *
@@ -1870,7 +2053,9 @@ static int ram_save_page(RAMState *rs, PageSearchStatus *pss, bool last_stage)
 static int ram_save_multifd_page(RAMState *rs, RAMBlock *block,
                                  ram_addr_t offset)
 {
-    multifd_queue_page(block, offset);
+    if (multifd_queue_page(block, offset) < 0) {
+        return -1;
+    }
     ram_counters.normal++;
 
     return 1;
@@ -2005,7 +2190,7 @@ retry:
  * find_dirty_block: find the next dirty page and update any state
  * associated with the search process.
  *
- * Returns if a page is found
+ * Returns true if a page is found
  *
  * @rs: current RAM state
  * @pss: data about the state of the current dirty page scan
@@ -2097,11 +2282,11 @@ static RAMBlock *unqueue_page(RAMState *rs, ram_addr_t *offset)
 }
 
 /**
- * get_queued_page: unqueue a page from the postocpy requests
+ * get_queued_page: unqueue a page from the postcopy requests
  *
  * Skips pages that are already sent (!dirty)
  *
- * Returns if a queued page is found
+ * Returns true if a queued page is found
  *
  * @rs: current RAM state
  * @pss: data about the state of the current dirty page scan
@@ -2151,6 +2336,12 @@ static bool get_queued_page(RAMState *rs, PageSearchStatus *pss)
          */
         pss->block = block;
         pss->page = offset >> TARGET_PAGE_BITS;
+
+        /*
+         * This unqueued page would break the "one round" check, even is
+         * really rare.
+         */
+        pss->complete_round = false;
     }
 
     return !!block;
@@ -2374,7 +2565,7 @@ static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss,
     size_t pagesize_bits =
         qemu_ram_pagesize(pss->block) >> TARGET_PAGE_BITS;
 
-    if (!qemu_ram_is_migratable(pss->block)) {
+    if (ramblock_is_ignored(pss->block)) {
         error_report("block %s should not be migrated !", pss->block->idstr);
         return 0;
     }
@@ -2472,19 +2663,30 @@ void acct_update_position(QEMUFile *f, size_t size, bool zero)
     }
 }
 
-uint64_t ram_bytes_total(void)
+static uint64_t ram_bytes_total_common(bool count_ignored)
 {
     RAMBlock *block;
     uint64_t total = 0;
 
     rcu_read_lock();
-    RAMBLOCK_FOREACH_MIGRATABLE(block) {
-        total += block->used_length;
+    if (count_ignored) {
+        RAMBLOCK_FOREACH_MIGRATABLE(block) {
+            total += block->used_length;
+        }
+    } else {
+        RAMBLOCK_FOREACH_NOT_IGNORED(block) {
+            total += block->used_length;
+        }
     }
     rcu_read_unlock();
     return total;
 }
 
+uint64_t ram_bytes_total(void)
+{
+    return ram_bytes_total_common(false);
+}
+
 static void xbzrle_load_setup(void)
 {
     XBZRLE.decoded_buf = g_malloc(TARGET_PAGE_SIZE);
@@ -2529,11 +2731,13 @@ static void ram_save_cleanup(void *opaque)
     RAMBlock *block;
 
     /* caller have hold iothread lock or is in a bh, so there is
-     * no writing race against this migration_bitmap
+     * no writing race against the migration bitmap
      */
     memory_global_dirty_log_stop();
 
-    RAMBLOCK_FOREACH_MIGRATABLE(block) {
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
+        g_free(block->clear_bmap);
+        block->clear_bmap = NULL;
         g_free(block->bmap);
         block->bmap = NULL;
         g_free(block->unsentmap);
@@ -2552,6 +2756,7 @@ static void ram_state_reset(RAMState *rs)
     rs->last_page = 0;
     rs->last_version = ram_list.version;
     rs->ram_bulk_stage = true;
+    rs->fpo_enabled = false;
 }
 
 #define MAX_WAIT 50 /* ms, half buffered_file limit */
@@ -2596,7 +2801,7 @@ void ram_postcopy_migrated_memory_release(MigrationState *ms)
 {
     struct RAMBlock *block;
 
-    RAMBLOCK_FOREACH_MIGRATABLE(block) {
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
         unsigned long *bitmap = block->bmap;
         unsigned long range = block->used_length >> TARGET_PAGE_BITS;
         unsigned long run_start = find_next_zero_bit(bitmap, range, 0);
@@ -2621,8 +2826,7 @@ void ram_postcopy_migrated_memory_release(MigrationState *ms)
  *
  * @ms: current migration state
  * @pds: state for postcopy
- * @start: RAMBlock starting page
- * @length: RAMBlock size
+ * @block: RAMBlock to discard
  */
 static int postcopy_send_discard_bm_ram(MigrationState *ms,
                                         PostcopyDiscardState *pds,
@@ -2674,7 +2878,7 @@ static int postcopy_each_ram_send_discard(MigrationState *ms)
     struct RAMBlock *block;
     int ret;
 
-    RAMBLOCK_FOREACH_MIGRATABLE(block) {
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
         PostcopyDiscardState *pds =
             postcopy_discard_send_init(ms, block->idstr);
 
@@ -2821,7 +3025,7 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
 }
 
 /**
- * postcopy_chuck_hostpages: discrad any partially sent host page
+ * postcopy_chunk_hostpages: discard any partially sent host page
  *
  * Utility for the outgoing postcopy code.
  *
@@ -2882,7 +3086,7 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms)
     rs->last_sent_block = NULL;
     rs->last_page = 0;
 
-    RAMBLOCK_FOREACH_MIGRATABLE(block) {
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
         unsigned long pages = block->used_length >> TARGET_PAGE_BITS;
         unsigned long *bitmap = block->bmap;
         unsigned long *unsentmap = block->unsentmap;
@@ -3033,9 +3237,9 @@ static int ram_state_init(RAMState **rsp)
     /*
      * Count the total number of pages used by ram blocks not including any
      * gaps due to alignment or unplugs.
+     * This must match with the initial values of dirty bitmap.
      */
     (*rsp)->migration_dirty_pages = ram_bytes_total() >> TARGET_PAGE_BITS;
-
     ram_state_reset(*rsp);
 
     return 0;
@@ -3043,15 +3247,39 @@ static int ram_state_init(RAMState **rsp)
 
 static void ram_list_init_bitmaps(void)
 {
+    MigrationState *ms = migrate_get_current();
     RAMBlock *block;
     unsigned long pages;
+    uint8_t shift;
 
     /* Skip setting bitmap if there is no RAM */
     if (ram_bytes_total()) {
-        RAMBLOCK_FOREACH_MIGRATABLE(block) {
+        shift = ms->clear_bitmap_shift;
+        if (shift > CLEAR_BITMAP_SHIFT_MAX) {
+            error_report("clear_bitmap_shift (%u) too big, using "
+                         "max value (%u)", shift, CLEAR_BITMAP_SHIFT_MAX);
+            shift = CLEAR_BITMAP_SHIFT_MAX;
+        } else if (shift < CLEAR_BITMAP_SHIFT_MIN) {
+            error_report("clear_bitmap_shift (%u) too small, using "
+                         "min value (%u)", shift, CLEAR_BITMAP_SHIFT_MIN);
+            shift = CLEAR_BITMAP_SHIFT_MIN;
+        }
+
+        RAMBLOCK_FOREACH_NOT_IGNORED(block) {
             pages = block->max_length >> TARGET_PAGE_BITS;
+            /*
+             * The initial dirty bitmap for migration must be set with all
+             * ones to make sure we'll migrate every guest RAM page to
+             * destination.
+             * Here we set RAMBlock.bmap all to 1 because when rebegin a
+             * new migration after a failed migration, ram_list.
+             * dirty_memory[DIRTY_MEMORY_MIGRATION] don't include the whole
+             * guest memory.
+             */
             block->bmap = bitmap_new(pages);
             bitmap_set(block->bmap, 0, pages);
+            block->clear_bmap_shift = shift;
+            block->clear_bmap = bitmap_new(clear_bmap_size(pages, shift));
             if (migrate_postcopy_ram()) {
                 block->unsentmap = bitmap_new(pages);
                 bitmap_set(block->unsentmap, 0, pages);
@@ -3069,7 +3297,7 @@ static void ram_init_bitmaps(RAMState *rs)
 
     ram_list_init_bitmaps();
     memory_global_dirty_log_start();
-    migration_bitmap_sync(rs);
+    migration_bitmap_sync_precopy(rs);
 
     rcu_read_unlock();
     qemu_mutex_unlock_ramlist();
@@ -3103,7 +3331,7 @@ static void ram_state_resume_prepare(RAMState *rs, QEMUFile *out)
      * about dirty page logging as well.
      */
 
-    RAMBLOCK_FOREACH_MIGRATABLE(block) {
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
         pages += bitmap_count_one(block->bmap,
                                   block->used_length >> TARGET_PAGE_BITS);
     }
@@ -3127,6 +3355,53 @@ static void ram_state_resume_prepare(RAMState *rs, QEMUFile *out)
     trace_ram_state_resume_prepare(pages);
 }
 
+/*
+ * This function clears bits of the free pages reported by the caller from the
+ * migration dirty bitmap. @addr is the host address corresponding to the
+ * start of the continuous guest free pages, and @len is the total bytes of
+ * those pages.
+ */
+void qemu_guest_free_page_hint(void *addr, size_t len)
+{
+    RAMBlock *block;
+    ram_addr_t offset;
+    size_t used_len, start, npages;
+    MigrationState *s = migrate_get_current();
+
+    /* This function is currently expected to be used during live migration */
+    if (!migration_is_setup_or_active(s->state)) {
+        return;
+    }
+
+    for (; len > 0; len -= used_len, addr += used_len) {
+        block = qemu_ram_block_from_host(addr, false, &offset);
+        if (unlikely(!block || offset >= block->used_length)) {
+            /*
+             * The implementation might not support RAMBlock resize during
+             * live migration, but it could happen in theory with future
+             * updates. So we add a check here to capture that case.
+             */
+            error_report_once("%s unexpected error", __func__);
+            return;
+        }
+
+        if (len <= block->used_length - offset) {
+            used_len = len;
+        } else {
+            used_len = block->used_length - offset;
+        }
+
+        start = offset >> TARGET_PAGE_BITS;
+        npages = used_len >> TARGET_PAGE_BITS;
+
+        qemu_mutex_lock(&ram_state->bitmap_mutex);
+        ram_state->migration_dirty_pages -=
+                      bitmap_count_one_with_offset(block->bmap, start, npages);
+        bitmap_clear(block->bmap, start, npages);
+        qemu_mutex_unlock(&ram_state->bitmap_mutex);
+    }
+}
+
 /*
  * Each of ram_save_setup, ram_save_iterate and ram_save_complete has
  * long-running RCU critical section.  When rcu-reclaims in the code
@@ -3162,7 +3437,7 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
 
     rcu_read_lock();
 
-    qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
+    qemu_put_be64(f, ram_bytes_total_common(true) | RAM_SAVE_FLAG_MEM_SIZE);
 
     RAMBLOCK_FOREACH_MIGRATABLE(block) {
         qemu_put_byte(f, strlen(block->idstr));
@@ -3171,6 +3446,9 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
         if (migrate_postcopy_ram() && block->page_size != qemu_host_page_size) {
             qemu_put_be64(f, block->page_size);
         }
+        if (migrate_ignore_shared()) {
+            qemu_put_be64(f, block->mr->addr);
+        }
     }
 
     rcu_read_unlock();
@@ -3245,7 +3523,7 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
 
         /* 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
+           qemu_clock_get_ns() is a bit expensive, so we only check each some
            iterations
         */
         if ((i & 63) == 0) {
@@ -3265,8 +3543,8 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
      */
     ram_control_after_iterate(f, RAM_CONTROL_ROUND);
 
-    multifd_send_sync_main();
 out:
+    multifd_send_sync_main();
     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
     qemu_fflush(f);
     ram_counters.transferred += 8;
@@ -3298,7 +3576,7 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
     rcu_read_lock();
 
     if (!migration_in_postcopy()) {
-        migration_bitmap_sync(rs);
+        migration_bitmap_sync_precopy(rs);
     }
 
     ram_control_before_iterate(f, RAM_CONTROL_FINISH);
@@ -3347,7 +3625,7 @@ static void ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size,
         remaining_size < max_size) {
         qemu_mutex_lock_iothread();
         rcu_read_lock();
-        migration_bitmap_sync(rs);
+        migration_bitmap_sync_precopy(rs);
         rcu_read_unlock();
         qemu_mutex_unlock_iothread();
         remaining_size = rs->migration_dirty_pages * TARGET_PAGE_SIZE;
@@ -3429,7 +3707,7 @@ static inline RAMBlock *ram_block_from_stream(QEMUFile *f, int flags)
         return NULL;
     }
 
-    if (!qemu_ram_is_migratable(block)) {
+    if (ramblock_is_ignored(block)) {
         error_report("block %s should not be migrated !", id);
         return NULL;
     }
@@ -3458,6 +3736,15 @@ static inline void *colo_cache_from_block_offset(RAMBlock *block,
                      __func__, block->idstr);
         return NULL;
     }
+
+    /*
+    * During colo checkpoint, we need bitmap of these migrated pages.
+    * It help us to decide which pages in ram cache should be flushed
+    * into VM's RAM later.
+    */
+    if (!test_and_set_bit(offset >> TARGET_PAGE_BITS, block->bmap)) {
+        ram_state->migration_dirty_pages++;
+    }
     return block->colo_cache + offset;
 }
 
@@ -3675,7 +3962,7 @@ int colo_init_ram_cache(void)
     RAMBlock *block;
 
     rcu_read_lock();
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
         block->colo_cache = qemu_anon_ram_alloc(block->used_length,
                                                 NULL,
                                                 false);
@@ -3688,10 +3975,31 @@ int colo_init_ram_cache(void)
         memcpy(block->colo_cache, block->host, block->used_length);
     }
     rcu_read_unlock();
+    /*
+    * Record the dirty pages that sent by PVM, we use this dirty bitmap together
+    * with to decide which page in cache should be flushed into SVM's RAM. Here
+    * we use the same name 'ram_bitmap' as for migration.
+    */
+    if (ram_bytes_total()) {
+        RAMBlock *block;
+
+        RAMBLOCK_FOREACH_NOT_IGNORED(block) {
+            unsigned long pages = block->max_length >> TARGET_PAGE_BITS;
+
+            block->bmap = bitmap_new(pages);
+            bitmap_set(block->bmap, 0, pages);
+        }
+    }
+    ram_state = g_new0(RAMState, 1);
+    ram_state->migration_dirty_pages = 0;
+    qemu_mutex_init(&ram_state->bitmap_mutex);
+    memory_global_dirty_log_start();
+
     return 0;
 
 out_locked:
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
         if (block->colo_cache) {
             qemu_anon_ram_free(block->colo_cache, block->used_length);
             block->colo_cache = NULL;
@@ -3707,14 +4015,25 @@ void colo_release_ram_cache(void)
 {
     RAMBlock *block;
 
+    memory_global_dirty_log_stop();
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
+        g_free(block->bmap);
+        block->bmap = NULL;
+    }
+
     rcu_read_lock();
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
         if (block->colo_cache) {
             qemu_anon_ram_free(block->colo_cache, block->used_length);
             block->colo_cache = NULL;
         }
     }
+
     rcu_read_unlock();
+    qemu_mutex_destroy(&ram_state->bitmap_mutex);
+    g_free(ram_state);
+    ram_state = NULL;
 }
 
 /**
@@ -3741,7 +4060,7 @@ static int ram_load_cleanup(void *opaque)
 {
     RAMBlock *rb;
 
-    RAMBLOCK_FOREACH_MIGRATABLE(rb) {
+    RAMBLOCK_FOREACH_NOT_IGNORED(rb) {
         if (ramblock_is_pmem(rb)) {
             pmem_persist(rb->host, rb->used_length);
         }
@@ -3750,7 +4069,7 @@ static int ram_load_cleanup(void *opaque)
     xbzrle_load_cleanup();
     compress_threads_load_cleanup();
 
-    RAMBLOCK_FOREACH_MIGRATABLE(rb) {
+    RAMBLOCK_FOREACH_NOT_IGNORED(rb) {
         g_free(rb->receivedmap);
         rb->receivedmap = NULL;
     }
@@ -3937,6 +4256,46 @@ static bool postcopy_is_running(void)
     return ps >= POSTCOPY_INCOMING_LISTENING && ps < POSTCOPY_INCOMING_END;
 }
 
+/*
+ * Flush content of RAM cache into SVM's memory.
+ * Only flush the pages that be dirtied by PVM or SVM or both.
+ */
+static void colo_flush_ram_cache(void)
+{
+    RAMBlock *block = NULL;
+    void *dst_host;
+    void *src_host;
+    unsigned long offset = 0;
+
+    memory_global_dirty_log_sync();
+    rcu_read_lock();
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
+        migration_bitmap_sync_range(ram_state, block, block->used_length);
+    }
+    rcu_read_unlock();
+
+    trace_colo_flush_ram_cache_begin(ram_state->migration_dirty_pages);
+    rcu_read_lock();
+    block = QLIST_FIRST_RCU(&ram_list.blocks);
+
+    while (block) {
+        offset = migration_bitmap_find_dirty(ram_state, block, offset);
+
+        if (offset << TARGET_PAGE_BITS >= block->used_length) {
+            offset = 0;
+            block = QLIST_NEXT_RCU(block, next);
+        } else {
+            migration_bitmap_clear_dirty(ram_state, block, offset);
+            dst_host = block->host + (offset << TARGET_PAGE_BITS);
+            src_host = block->colo_cache + (offset << TARGET_PAGE_BITS);
+            memcpy(dst_host, src_host, TARGET_PAGE_SIZE);
+        }
+    }
+
+    rcu_read_unlock();
+    trace_colo_flush_ram_cache_end();
+}
+
 static int ram_load(QEMUFile *f, void *opaque, int version_id)
 {
     int flags = 0, ret = 0, invalid_flags = 0;
@@ -4053,6 +4412,17 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
                             ret = -EINVAL;
                         }
                     }
+                    if (migrate_ignore_shared()) {
+                        hwaddr addr = qemu_get_be64(f);
+                        if (ramblock_is_ignored(block) &&
+                            block->mr->addr != addr) {
+                            error_report("Mismatched GPAs for block %s "
+                                         "%" PRId64 "!= %" PRId64,
+                                         id, (uint64_t)addr,
+                                         (uint64_t)block->mr->addr);
+                            ret = -EINVAL;
+                        }
+                    }
                     ram_control_load_hook(f, RAM_CONTROL_BLOCK_REG,
                                           block->idstr);
                 } else {
@@ -4113,13 +4483,17 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
     ret |= wait_for_decompress_done();
     rcu_read_unlock();
     trace_ram_load_complete(ret, seq_iter);
+
+    if (!ret  && migration_incoming_in_colo_state()) {
+        colo_flush_ram_cache();
+    }
     return ret;
 }
 
 static bool ram_has_postcopy(void *opaque)
 {
     RAMBlock *rb;
-    RAMBLOCK_FOREACH_MIGRATABLE(rb) {
+    RAMBLOCK_FOREACH_NOT_IGNORED(rb) {
         if (ramblock_is_pmem(rb)) {
             info_report("Block: %s, host: %p is a nvdimm memory, postcopy"
                          "is not supported now!", rb->idstr, rb->host);
@@ -4139,7 +4513,7 @@ static int ram_dirty_bitmap_sync_all(MigrationState *s, RAMState *rs)
 
     trace_ram_dirty_bitmap_sync_start();
 
-    RAMBLOCK_FOREACH_MIGRATABLE(block) {
+    RAMBLOCK_FOREACH_NOT_IGNORED(block) {
         qemu_savevm_send_recv_bitmap(file, block->idstr);
         trace_ram_dirty_bitmap_request(block->idstr);
         ramblock_count++;
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