Merge remote-tracking branch 'remotes/amit-migration/tags/migration-for-2.6-1' into staging

migration fixes for postcopy, xbzrle, multithread decompression

# gpg: Signature made Wed 13 Jan 2016 10:34:49 GMT using RSA key ID 854083B6
# gpg: Good signature from "Amit Shah <amit@amitshah.net>"
# gpg:                 aka "Amit Shah <amit@kernel.org>"
# gpg:                 aka "Amit Shah <amitshah@gmx.net>"

* remotes/amit-migration/tags/migration-for-2.6-1:
  multithread decompression: Avoid one copy
  Use qemu_get_buffer_in_place for xbzrle data
  Migration: Emit event at start of pass
  Postcopy: Send events/change state on incoming side
  migration: Add state records for migration incoming
  migration: Export migrate_set_state()

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

6 files changed, 87 insertions, 38 deletions

diff --git a/docs/qmp-events.txt b/docs/qmp-events.txt
index d2f1ce497e..52eb7e2f5e 100644
--- a/docs/qmp-events.txt
+++ b/docs/qmp-events.txt
@@ -496,6 +496,20 @@ Example:
 {"timestamp": {"seconds": 1432121972, "microseconds": 744001},
  "event": "MIGRATION", "data": {"status": "completed"}}
 
+MIGRATION_PASS
+--------------
+
+Emitted from the source side of a migration at the start of each pass
+(when it syncs the dirty bitmap)
+
+Data: None.
+
+  - "pass": An incrementing count (starting at 1 on the first pass)
+
+Example:
+{"timestamp": {"seconds": 1449669631, "microseconds": 239225},
+ "event": "MIGRATION_PASS", "data": {"pass": 2}}
+
 STOP
 ----
 
diff --git a/include/migration/migration.h b/include/migration/migration.h
index d9494b895e..0fc1ffa9a9 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -105,6 +105,7 @@ struct MigrationIncomingState {
     QemuMutex rp_mutex;    /* We send replies from multiple threads */
     void     *postcopy_tmp_page;
 
+    int state;
     /* See savevm.c */
     LoadStateEntry_Head loadvm_handlers;
 };
@@ -169,6 +170,8 @@ struct MigrationState
     RAMBlock *last_req_rb;
 };
 
+void migrate_set_state(int *state, int old_state, int new_state);
+
 void process_incoming_migration(QEMUFile *f);
 
 void qemu_start_incoming_migration(const char *uri, Error **errp);
diff --git a/migration/migration.c b/migration/migration.c
index c842499575..bc611e453b 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -111,6 +111,7 @@ MigrationIncomingState *migration_incoming_state_new(QEMUFile* f)
 {
     mis_current = g_new0(MigrationIncomingState, 1);
     mis_current->from_src_file = f;
+    mis_current->state = MIGRATION_STATUS_NONE;
     QLIST_INIT(&mis_current->loadvm_handlers);
     qemu_mutex_init(&mis_current->rp_mutex);
     qemu_event_init(&mis_current->main_thread_load_event, false);
@@ -331,8 +332,8 @@ static void process_incoming_migration_co(void *opaque)
 
     mis = migration_incoming_state_new(f);
     postcopy_state_set(POSTCOPY_INCOMING_NONE);
-    migrate_generate_event(MIGRATION_STATUS_ACTIVE);
-
+    migrate_set_state(&mis->state, MIGRATION_STATUS_NONE,
+                      MIGRATION_STATUS_ACTIVE);
     ret = qemu_loadvm_state(f);
 
     ps = postcopy_state_get();
@@ -358,10 +359,10 @@ static void process_incoming_migration_co(void *opaque)
 
     qemu_fclose(f);
     free_xbzrle_decoded_buf();
-    migration_incoming_state_destroy();
 
     if (ret < 0) {
-        migrate_generate_event(MIGRATION_STATUS_FAILED);
+        migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
+                          MIGRATION_STATUS_FAILED);
         error_report("load of migration failed: %s", strerror(-ret));
         migrate_decompress_threads_join();
         exit(EXIT_FAILURE);
@@ -370,7 +371,8 @@ static void process_incoming_migration_co(void *opaque)
     /* Make sure all file formats flush their mutable metadata */
     bdrv_invalidate_cache_all(&local_err);
     if (local_err) {
-        migrate_generate_event(MIGRATION_STATUS_FAILED);
+        migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
+                          MIGRATION_STATUS_FAILED);
         error_report_err(local_err);
         migrate_decompress_threads_join();
         exit(EXIT_FAILURE);
@@ -402,7 +404,9 @@ static void process_incoming_migration_co(void *opaque)
      * observer sees this event they might start to prod at the VM assuming
      * it's ready to use.
      */
-    migrate_generate_event(MIGRATION_STATUS_COMPLETED);
+    migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
+                      MIGRATION_STATUS_COMPLETED);
+    migration_incoming_state_destroy();
 }
 
 void process_incoming_migration(QEMUFile *f)
@@ -787,9 +791,9 @@ void qmp_migrate_start_postcopy(Error **errp)
 
 /* shared migration helpers */
 
-static void migrate_set_state(MigrationState *s, int old_state, int new_state)
+void migrate_set_state(int *state, int old_state, int new_state)
 {
-    if (atomic_cmpxchg(&s->state, old_state, new_state) == old_state) {
+    if (atomic_cmpxchg(state, old_state, new_state) == old_state) {
         trace_migrate_set_state(new_state);
         migrate_generate_event(new_state);
     }
@@ -822,7 +826,7 @@ static void migrate_fd_cleanup(void *opaque)
            (s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE));
 
     if (s->state == MIGRATION_STATUS_CANCELLING) {
-        migrate_set_state(s, MIGRATION_STATUS_CANCELLING,
+        migrate_set_state(&s->state, MIGRATION_STATUS_CANCELLING,
                           MIGRATION_STATUS_CANCELLED);
     }
 
@@ -833,7 +837,8 @@ void migrate_fd_error(MigrationState *s)
 {
     trace_migrate_fd_error();
     assert(s->file == NULL);
-    migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_FAILED);
+    migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
+                      MIGRATION_STATUS_FAILED);
     notifier_list_notify(&migration_state_notifiers, s);
 }
 
@@ -853,7 +858,7 @@ static void migrate_fd_cancel(MigrationState *s)
         if (!migration_is_setup_or_active(old_state)) {
             break;
         }
-        migrate_set_state(s, old_state, MIGRATION_STATUS_CANCELLING);
+        migrate_set_state(&s->state, old_state, MIGRATION_STATUS_CANCELLING);
     } while (s->state != MIGRATION_STATUS_CANCELLING);
 
     /*
@@ -927,7 +932,7 @@ MigrationState *migrate_init(const MigrationParams *params)
     s->migration_thread_running = false;
     s->last_req_rb = NULL;
 
-    migrate_set_state(s, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
+    migrate_set_state(&s->state, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP);
 
     QSIMPLEQ_INIT(&s->src_page_requests);
 
@@ -1026,7 +1031,8 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
     } else {
         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "uri",
                    "a valid migration protocol");
-        migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_FAILED);
+        migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
+                          MIGRATION_STATUS_FAILED);
         return;
     }
 
@@ -1405,7 +1411,7 @@ static int postcopy_start(MigrationState *ms, bool *old_vm_running)
     int ret;
     const QEMUSizedBuffer *qsb;
     int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
-    migrate_set_state(ms, MIGRATION_STATUS_ACTIVE,
+    migrate_set_state(&ms->state, MIGRATION_STATUS_ACTIVE,
                       MIGRATION_STATUS_POSTCOPY_ACTIVE);
 
     trace_postcopy_start();
@@ -1496,7 +1502,7 @@ static int postcopy_start(MigrationState *ms, bool *old_vm_running)
     ret = qemu_file_get_error(ms->file);
     if (ret) {
         error_report("postcopy_start: Migration stream errored");
-        migrate_set_state(ms, MIGRATION_STATUS_POSTCOPY_ACTIVE,
+        migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
                               MIGRATION_STATUS_FAILED);
     }
 
@@ -1505,7 +1511,7 @@ static int postcopy_start(MigrationState *ms, bool *old_vm_running)
 fail_closefb:
     qemu_fclose(fb);
 fail:
-    migrate_set_state(ms, MIGRATION_STATUS_POSTCOPY_ACTIVE,
+    migrate_set_state(&ms->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
                           MIGRATION_STATUS_FAILED);
     qemu_mutex_unlock_iothread();
     return -1;
@@ -1574,11 +1580,13 @@ static void migration_completion(MigrationState *s, int current_active_state,
         goto fail;
     }
 
-    migrate_set_state(s, current_active_state, MIGRATION_STATUS_COMPLETED);
+    migrate_set_state(&s->state, current_active_state,
+                      MIGRATION_STATUS_COMPLETED);
     return;
 
 fail:
-    migrate_set_state(s, current_active_state, MIGRATION_STATUS_FAILED);
+    migrate_set_state(&s->state, current_active_state,
+                      MIGRATION_STATUS_FAILED);
 }
 
 /*
@@ -1623,7 +1631,8 @@ static void *migration_thread(void *opaque)
 
     s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
     current_active_state = MIGRATION_STATUS_ACTIVE;
-    migrate_set_state(s, MIGRATION_STATUS_SETUP, MIGRATION_STATUS_ACTIVE);
+    migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
+                      MIGRATION_STATUS_ACTIVE);
 
     trace_migration_thread_setup_complete();
 
@@ -1666,7 +1675,8 @@ static void *migration_thread(void *opaque)
         }
 
         if (qemu_file_get_error(s->file)) {
-            migrate_set_state(s, current_active_state, MIGRATION_STATUS_FAILED);
+            migrate_set_state(&s->state, current_active_state,
+                              MIGRATION_STATUS_FAILED);
             trace_migration_thread_file_err();
             break;
         }
@@ -1747,7 +1757,7 @@ void migrate_fd_connect(MigrationState *s)
     if (migrate_postcopy_ram()) {
         if (open_return_path_on_source(s)) {
             error_report("Unable to open return-path for postcopy");
-            migrate_set_state(s, MIGRATION_STATUS_SETUP,
+            migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
                               MIGRATION_STATUS_FAILED);
             migrate_fd_cleanup(s);
             return;
diff --git a/migration/ram.c b/migration/ram.c
index 0490f005dd..2da3b51e30 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -27,6 +27,7 @@
  */
 #include <stdint.h>
 #include <zlib.h>
+#include "qapi-event.h"
 #include "qemu/bitops.h"
 #include "qemu/bitmap.h"
 #include "qemu/timer.h"
@@ -285,7 +286,6 @@ static bool quit_comp_thread;
 static bool quit_decomp_thread;
 static DecompressParam *decomp_param;
 static QemuThread *decompress_threads;
-static uint8_t *compressed_data_buf;
 
 static int do_compress_ram_page(CompressParam *param);
 
@@ -682,6 +682,9 @@ static void migration_bitmap_sync(void)
         num_dirty_pages_period = 0;
     }
     s->dirty_sync_count = bitmap_sync_count;
+    if (migrate_use_events()) {
+        qapi_event_send_migration_pass(bitmap_sync_count, NULL);
+    }
 }
 
 /**
@@ -2084,10 +2087,12 @@ static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
 {
     unsigned int xh_len;
     int xh_flags;
+    uint8_t *loaded_data;
 
     if (!xbzrle_decoded_buf) {
         xbzrle_decoded_buf = g_malloc(TARGET_PAGE_SIZE);
     }
+    loaded_data = xbzrle_decoded_buf;
 
     /* extract RLE header */
     xh_flags = qemu_get_byte(f);
@@ -2103,10 +2108,10 @@ static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
         return -1;
     }
     /* load data and decode */
-    qemu_get_buffer(f, xbzrle_decoded_buf, xh_len);
+    qemu_get_buffer_in_place(f, &loaded_data, xh_len);
 
     /* decode RLE */
-    if (xbzrle_decode_buffer(xbzrle_decoded_buf, xh_len, host,
+    if (xbzrle_decode_buffer(loaded_data, xh_len, host,
                              TARGET_PAGE_SIZE) == -1) {
         error_report("Failed to load XBZRLE page - decode error!");
         return -1;
@@ -2201,7 +2206,6 @@ void migrate_decompress_threads_create(void)
     thread_count = migrate_decompress_threads();
     decompress_threads = g_new0(QemuThread, thread_count);
     decomp_param = g_new0(DecompressParam, thread_count);
-    compressed_data_buf = g_malloc0(compressBound(TARGET_PAGE_SIZE));
     quit_decomp_thread = false;
     for (i = 0; i < thread_count; i++) {
         qemu_mutex_init(&decomp_param[i].mutex);
@@ -2232,13 +2236,11 @@ void migrate_decompress_threads_join(void)
     }
     g_free(decompress_threads);
     g_free(decomp_param);
-    g_free(compressed_data_buf);
     decompress_threads = NULL;
     decomp_param = NULL;
-    compressed_data_buf = NULL;
 }
 
-static void decompress_data_with_multi_threads(uint8_t *compbuf,
+static void decompress_data_with_multi_threads(QEMUFile *f,
                                                void *host, int len)
 {
     int idx, thread_count;
@@ -2247,7 +2249,7 @@ static void decompress_data_with_multi_threads(uint8_t *compbuf,
     while (true) {
         for (idx = 0; idx < thread_count; idx++) {
             if (!decomp_param[idx].start) {
-                memcpy(decomp_param[idx].compbuf, compbuf, len);
+                qemu_get_buffer(f, decomp_param[idx].compbuf, len);
                 decomp_param[idx].des = host;
                 decomp_param[idx].len = len;
                 start_decompression(&decomp_param[idx]);
@@ -2492,8 +2494,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
                 ret = -EINVAL;
                 break;
             }
-            qemu_get_buffer(f, compressed_data_buf, len);
-            decompress_data_with_multi_threads(compressed_data_buf, host, len);
+            decompress_data_with_multi_threads(f, host, len);
             break;
 
         case RAM_SAVE_FLAG_XBZRLE:
diff --git a/migration/savevm.c b/migration/savevm.c
index 0ad1b93a8b..c469bad65c 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1399,6 +1399,8 @@ static void *postcopy_ram_listen_thread(void *opaque)
     MigrationIncomingState *mis = migration_incoming_get_current();
     int load_res;
 
+    migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
+                                   MIGRATION_STATUS_POSTCOPY_ACTIVE);
     qemu_sem_post(&mis->listen_thread_sem);
     trace_postcopy_ram_listen_thread_start();
 
@@ -1415,6 +1417,8 @@ static void *postcopy_ram_listen_thread(void *opaque)
     if (load_res < 0) {
         error_report("%s: loadvm failed: %d", __func__, load_res);
         qemu_file_set_error(f, load_res);
+        migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
+                                       MIGRATION_STATUS_FAILED);
     } else {
         /*
          * This looks good, but it's possible that the device loading in the
@@ -1424,13 +1428,6 @@ static void *postcopy_ram_listen_thread(void *opaque)
         qemu_event_wait(&mis->main_thread_load_event);
     }
     postcopy_ram_incoming_cleanup(mis);
-    /*
-     * If everything has worked fine, then the main thread has waited
-     * for us to start, and we're the last use of the mis.
-     * (If something broke then qemu will have to exit anyway since it's
-     * got a bad migration state).
-     */
-    migration_incoming_state_destroy();
 
     if (load_res < 0) {
         /*
@@ -1442,6 +1439,17 @@ static void *postcopy_ram_listen_thread(void *opaque)
         exit(EXIT_FAILURE);
     }
 
+    migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,
+                                   MIGRATION_STATUS_COMPLETED);
+    /*
+     * If everything has worked fine, then the main thread has waited
+     * for us to start, and we're the last use of the mis.
+     * (If something broke then qemu will have to exit anyway since it's
+     * got a bad migration state).
+     */
+    migration_incoming_state_destroy();
+
+
     return NULL;
 }
 
diff --git a/qapi/event.json b/qapi/event.json
index f0cef010f0..390fd45788 100644
--- a/qapi/event.json
+++ b/qapi/event.json
@@ -255,6 +255,19 @@
   'data': {'status': 'MigrationStatus'}}
 
 ##
+# @MIGRATION_PASS
+#
+# Emitted from the source side of a migration at the start of each pass
+# (when it syncs the dirty bitmap)
+#
+# @pass: An incrementing count (starting at 1 on the first pass)
+#
+# Since: 2.6
+##
+{ 'event': 'MIGRATION_PASS',
+  'data': { 'pass': 'int' } }
+
+##
 # @ACPI_DEVICE_OST
 #
 # Emitted when guest executes ACPI _OST method.