[Qemu-devel] [PATCH 1/3] stop dirty tracking just at the end of migration

[Glauber Costa <glommer@redhat.com>]

If there is still work to do, it is not safe to assume we
can end the dirty tracking. Specifically, kvm can update the dirty
tracking log inside ram_save_block(), leaving pages still out of sync
if we go with the current code.

Based on a patch by Yaniv Kamay

Signed-off-by: Glauber Costa <glommer@redhat.com>
CC: Yaniv Kamay <ykamay@redhat.com>
CC: Dor Laor <dlaor@redhat.com>
---
 vl.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/vl.c b/vl.c
index 5e6c621..1626f8a 100644
--- a/vl.c
+++ b/vl.c
@@ -3249,10 +3249,10 @@ static int ram_save_live(QEMUFile *f, int stage, void *opaque)
     /* try transferring iterative blocks of memory */
 
     if (stage == 3) {
-        cpu_physical_memory_set_dirty_tracking(0);
 
         /* flush all remaining blocks regardless of rate limiting */
         while (ram_save_block(f) != 0);
+        cpu_physical_memory_set_dirty_tracking(0);
     }
 
     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
-- 
1.5.6.6