[Qemu-devel] [PULL 27/57] Modify save_live_pending for postcopy

[Juan Quintela <quintela@redhat.com>]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Modify save_live_pending to return separate postcopiable and
non-postcopiable counts.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 include/migration/vmstate.h |  5 +++--
 include/sysemu/sysemu.h     |  4 +++-
 migration/block.c           |  7 +++++--
 migration/migration.c       |  9 +++++++--
 migration/ram.c             |  8 ++++++--
 migration/savevm.c          | 17 +++++++++++++----
 trace-events                |  2 +-
 7 files changed, 38 insertions(+), 14 deletions(-)

diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index 9986ccc..7f16a38 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -54,8 +54,9 @@ typedef struct SaveVMHandlers {

     /* This runs outside the iothread lock!  */
     int (*save_live_setup)(QEMUFile *f, void *opaque);
-    uint64_t (*save_live_pending)(QEMUFile *f, void *opaque, uint64_t max_size);
-
+    void (*save_live_pending)(QEMUFile *f, void *opaque, uint64_t max_size,
+                              uint64_t *non_postcopiable_pending,
+                              uint64_t *postcopiable_pending);
     LoadStateHandler *load_state;
 } SaveVMHandlers;

diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index c27b926..70835d0 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -112,7 +112,9 @@ void qemu_savevm_state_header(QEMUFile *f);
 int qemu_savevm_state_iterate(QEMUFile *f);
 void qemu_savevm_state_cleanup(void);
 void qemu_savevm_state_complete_precopy(QEMUFile *f);
-uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size);
+void qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size,
+                               uint64_t *res_non_postcopiable,
+                               uint64_t *res_postcopiable);
 void qemu_savevm_command_send(QEMUFile *f, enum qemu_vm_cmd command,
                               uint16_t len, uint8_t *data);
 void qemu_savevm_send_ping(QEMUFile *f, uint32_t value);
diff --git a/migration/block.c b/migration/block.c
index 4fb9b7c..310e2b3 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -748,7 +748,9 @@ static int block_save_complete(QEMUFile *f, void *opaque)
     return 0;
 }

-static uint64_t block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
+static void block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size,
+                               uint64_t *non_postcopiable_pending,
+                               uint64_t *postcopiable_pending)
 {
     /* Estimate pending number of bytes to send */
     uint64_t pending;
@@ -767,7 +769,8 @@ static uint64_t block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
     qemu_mutex_unlock_iothread();

     DPRINTF("Enter save live pending  %" PRIu64 "\n", pending);
-    return pending;
+    /* We don't do postcopy */
+    *non_postcopiable_pending += pending;
 }

 static int block_load(QEMUFile *f, void *opaque, int version_id)
diff --git a/migration/migration.c b/migration/migration.c
index 74477a0..28eaf4b 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1288,8 +1288,13 @@ static void *migration_thread(void *opaque)
         uint64_t pending_size;

         if (!qemu_file_rate_limit(s->file)) {
-            pending_size = qemu_savevm_state_pending(s->file, max_size);
-            trace_migrate_pending(pending_size, max_size);
+            uint64_t pend_post, pend_nonpost;
+
+            qemu_savevm_state_pending(s->file, max_size, &pend_nonpost,
+                                      &pend_post);
+            pending_size = pend_nonpost + pend_post;
+            trace_migrate_pending(pending_size, max_size,
+                                  pend_post, pend_nonpost);
             if (pending_size && pending_size >= max_size) {
                 qemu_savevm_state_iterate(s->file);
             } else {
diff --git a/migration/ram.c b/migration/ram.c
index 4fa44a7..0e53325 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1383,7 +1383,9 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
     return 0;
 }

-static uint64_t ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
+static void ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size,
+                             uint64_t *non_postcopiable_pending,
+                             uint64_t *postcopiable_pending)
 {
     uint64_t remaining_size;

@@ -1397,7 +1399,9 @@ static uint64_t ram_save_pending(QEMUFile *f, void *opaque, uint64_t max_size)
         qemu_mutex_unlock_iothread();
         remaining_size = ram_save_remaining() * TARGET_PAGE_SIZE;
     }
-    return remaining_size;
+
+    /* We can do postcopy, and all the data is postcopiable */
+    *postcopiable_pending += remaining_size;
 }

 static int load_xbzrle(QEMUFile *f, ram_addr_t addr, void *host)
diff --git a/migration/savevm.c b/migration/savevm.c
index 01fdc72..44f4ded 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1053,10 +1053,19 @@ void qemu_savevm_state_complete_precopy(QEMUFile *f)
     qemu_fflush(f);
 }

-uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size)
+/* Give an estimate of the amount left to be transferred,
+ * the result is split into the amount for units that can and
+ * for units that can't do postcopy.
+ */
+void qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size,
+                               uint64_t *res_non_postcopiable,
+                               uint64_t *res_postcopiable)
 {
     SaveStateEntry *se;
-    uint64_t ret = 0;
+
+    *res_non_postcopiable = 0;
+    *res_postcopiable = 0;
+

     QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
         if (!se->ops || !se->ops->save_live_pending) {
@@ -1067,9 +1076,9 @@ uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size)
                 continue;
             }
         }
-        ret += se->ops->save_live_pending(f, se->opaque, max_size);
+        se->ops->save_live_pending(f, se->opaque, max_size,
+                                   res_non_postcopiable, res_postcopiable);
     }
-    return ret;
 }

 void qemu_savevm_state_cleanup(void)
diff --git a/trace-events b/trace-events
index b908c19..d319cf8 100644
--- a/trace-events
+++ b/trace-events
@@ -1450,7 +1450,7 @@ migrate_set_state(int new_state) "new state %d"
 migrate_fd_cleanup(void) ""
 migrate_fd_error(void) ""
 migrate_fd_cancel(void) ""
-migrate_pending(uint64_t size, uint64_t max) "pending size %" PRIu64 " max %" PRIu64
+migrate_pending(uint64_t size, uint64_t max, uint64_t post, uint64_t nonpost) "pending size %" PRIu64 " max %" PRIu64 " (post=%" PRIu64 " nonpost=%" PRIu64 ")"
 migrate_send_rp_message(int msg_type, uint16_t len) "%d: len %d"
 open_return_path_on_source(void) ""
 open_return_path_on_source_continue(void) ""
-- 
2.5.0