[11/11] So we use multifd to transmit zero pages.

Commit Message

Juan Quintela Nov. 28, 2022, 10:04 a.m. UTC

Signed-off-by: Juan Quintela <[e-mail]>

---

- Check zero_page property before using new code (Dave)
---
 migration/migration.c |  3 +--
 migration/ram.c       | 32 +++++++++++++++++++++++++++++++-
 2 files changed, 32 insertions(+), 3 deletions(-)

Patch

diff --git a/migration/migration.c b/migration/migration.c
index 2a828764ed..1cdeeb19b8 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2616,8 +2616,7 @@  bool migrate_use_main_zero_page(void)
 {
     MigrationState *s = migrate_get_current();
 
-    /* We will enable this when we add the right code. */
-    return true || s->enabled_capabilities[MIGRATION_CAPABILITY_MAIN_ZERO_PAGE];
+    return s->enabled_capabilities[MIGRATION_CAPABILITY_MAIN_ZERO_PAGE];
 }
 
 bool migrate_pause_before_switchover(void)
diff --git a/migration/ram.c b/migration/ram.c
index f23a01719b..f14ee63728 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2404,6 +2404,31 @@  out:
     return ret;
 }
 
+/**
+ * ram_save_target_page_multifd: save one target page
+ *
+ * Returns the number of pages written
+ *
+ * @rs: current RAM state
+ * @pss: data about the page we want to send
+ */
+static int ram_save_target_page_multifd(RAMState *rs, PageSearchStatus *pss)
+{
+    RAMBlock *block = pss->block;
+    ram_addr_t offset = ((ram_addr_t)pss->page) << TARGET_PAGE_BITS;
+
+    if (!migration_in_postcopy()) {
+        return ram_save_multifd_page(pss->pss_channel, block, offset);
+    }
+
+    int res = save_zero_page(pss, block, offset);
+    if (res > 0) {
+        return res;
+    }
+
+    return ram_save_page(rs, pss);
+}
+
 /**
  * ram_save_host_page: save a whole host page
  *
@@ -3206,7 +3231,12 @@  static int ram_save_setup(QEMUFile *f, void *opaque)
     ram_control_after_iterate(f, RAM_CONTROL_SETUP);
 
     migration_ops = g_malloc0(sizeof(MigrationOps));
-    migration_ops->ram_save_target_page = ram_save_target_page_legacy;
+    if (migrate_use_multifd() && !migrate_use_main_zero_page()) {
+        migration_ops->ram_save_target_page = ram_save_target_page_multifd;
+    } else {
+        migration_ops->ram_save_target_page = ram_save_target_page_legacy;
+    }
+
     ret =  multifd_send_sync_main(f);
     if (ret < 0) {
         return ret;