From c4bfb4900b95e13bef2d86b83c33786c7c4f6289 Mon Sep 17 00:00:00 2001
From: Juan Quintela <quintela@redhat.com>
Date: Tue, 21 Jun 2022 12:21:32 +0200
Subject: [PATCH 06/12] multifd: Protect multifd_send_sync_main() calls
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RH-Author: quintela1 <quintela@redhat.com>
RH-MergeRequest: 186: Multifd flushes its channels 10 times per second
RH-Bugzilla: 2196295
RH-Acked-by: Peter Xu <peterx@redhat.com>
RH-Acked-by: Leonardo BrĂ¡s <leobras@redhat.com>
RH-Commit: [2/3] a91adf59c6b2f39bf4a308f566b00e39cae6e0ae (juan.quintela/c9s-qemu-kvm)

We only need to do that on the ram_save_iterate() call on sending and
on destination when we get a RAM_SAVE_FLAG_EOS.

In setup() and complete() we need to synch in both new and old cases,
so don't add a check there.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>

---

Remove the wrappers that we take out on patch 5.

(cherry picked from commit b05292c237030343516d073b1a1e5f49ffc017a8)
---
 migration/ram.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 01356f60a4..1e2414d681 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -3394,9 +3394,11 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
 out:
     if (ret >= 0
         && migration_is_setup_or_active(migrate_get_current()->state)) {
-        ret = multifd_send_sync_main(rs->pss[RAM_CHANNEL_PRECOPY].pss_channel);
-        if (ret < 0) {
-            return ret;
+        if (migrate_multifd_flush_after_each_section()) {
+            ret = multifd_send_sync_main(rs->pss[RAM_CHANNEL_PRECOPY].pss_channel);
+            if (ret < 0) {
+                return ret;
+            }
         }
 
         qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
@@ -4153,7 +4155,9 @@ int ram_load_postcopy(QEMUFile *f, int channel)
 
         case RAM_SAVE_FLAG_EOS:
             /* normal exit */
-            multifd_recv_sync_main();
+            if (migrate_multifd_flush_after_each_section()) {
+                multifd_recv_sync_main();
+            }
             break;
         default:
             error_report("Unknown combination of migration flags: 0x%x"
@@ -4424,7 +4428,9 @@ static int ram_load_precopy(QEMUFile *f)
             break;
         case RAM_SAVE_FLAG_EOS:
             /* normal exit */
-            multifd_recv_sync_main();
+            if (migrate_multifd_flush_after_each_section()) {
+                multifd_recv_sync_main();
+            }
             break;
         default:
             if (flags & RAM_SAVE_FLAG_HOOK) {
-- 
2.39.3