From 0f7e704a4faa661583ea6d82659f206e561f23d4 Mon Sep 17 00:00:00 2001
From: Wei Yang <richardw.yang@linux.intel.com>
Date: Sat, 26 Oct 2019 07:19:59 +0800
Subject: [PATCH 3/8] migration/multifd: clean pages after filling packet

This is a preparation for the next patch:

    not use multifd during postcopy.

Without enabling postcopy, everything looks good. While after enabling
postcopy, migration may fail even not use multifd during postcopy. The
reason is the pages is not properly cleared and *old* target page will
continue to be transferred.

After clean pages, migration succeeds.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 migration/ram.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 840e354..c2eb1ed 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -947,10 +947,10 @@ static int multifd_send_pages(RAMState *rs)
         }
         qemu_mutex_unlock(&p->mutex);
     }
-    p->pages->used = 0;
+    assert(!p->pages->used);
+    assert(!p->pages->block);
 
     p->packet_num = multifd_send_state->packet_num++;
-    p->pages->block = NULL;
     multifd_send_state->pages = p->pages;
     p->pages = pages;
     transferred = ((uint64_t) pages->used) * TARGET_PAGE_SIZE + p->packet_len;
@@ -1137,6 +1137,7 @@ static void *multifd_send_thread(void *opaque)
             p->num_packets++;
             p->num_pages += used;
             p->pages->used = 0;
+            p->pages->block = NULL;
             qemu_mutex_unlock(&p->mutex);
 
             trace_multifd_send(p->id, packet_num, used, flags,
-- 
1.8.3.1