[Qemu-devel] [PATCH COLO-Frame v15 37/38] COLO: flush buffered packets in checkpoint process or exit COLO

[zhanghailiang <zhang.zhanghailiang@huawei.com>]

In COLO periodic mode, the packets from VM should not be sent
during the time interval of two checkpoints, we will release
all these buffered packets after the checkpoint process, before
VM is resumed.

In this way, we can ensure not to break the network services if
COLO goes into failover process.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Yang Hongyang <hongyang.yang@easystack.cn>
---
v15:
- Re-implement colo_flush_filter_packets() based on COLOBufferFilters list
---
 migration/colo.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/migration/colo.c b/migration/colo.c
index 4c39204..a2d489b 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -124,6 +124,17 @@ static void colo_set_filter_status(const char *status, Error **errp)
     }
 }
 
+static void colo_flush_filter_packets(Error **errp)
+{
+    struct COLOListNode *e, *next;
+    NetFilterState *nf;
+
+    QLIST_FOREACH_SAFE(e, &COLOBufferFilters, node, next) {
+        nf = e->opaque;
+        filter_buffer_flush(nf);
+    }
+}
+
 static void primary_vm_do_failover(void)
 {
     MigrationState *s = migrate_get_current();
@@ -157,6 +168,7 @@ static void primary_vm_do_failover(void)
     if (local_err) {
         error_report_err(local_err);
     }
+    colo_flush_filter_packets(NULL);
 
     /* Notify COLO thread that failover work is finished */
     qemu_sem_post(&s->colo_sem);
@@ -364,6 +376,8 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     if (local_err) {
         goto out;
     }
+    /* FIXME: Remove this after switch to use colo-proxy */
+    colo_flush_filter_packets(NULL);
 
     if (colo_shutdown_requested) {
         colo_put_cmd(s->to_dst_file, COLO_MESSAGE_GUEST_SHUTDOWN, &local_err);
-- 
1.8.3.1