colo-compare: implement the process of checkpoint

While do checkpoint, we need to flush all the unhandled packets,
By using the filter notifier mechanism, we can easily to notify
every compare object to do this process, which runs inside
of compare threads as a coroutine.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Zhang Chen <zhangckid@gmail.com>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

1 files changed, 78 insertions, 0 deletions

diff --git a/net/colo-compare.c b/net/colo-compare.c
index dd745a491b..80e6532e8b 100644
--- a/net/colo-compare.c
+++ b/net/colo-compare.c
@@ -27,11 +27,16 @@
 #include "qemu/sockets.h"
 #include "colo.h"
 #include "sysemu/iothread.h"
+#include "net/colo-compare.h"
+#include "migration/colo.h"
 
 #define TYPE_COLO_COMPARE "colo-compare"
 #define COLO_COMPARE(obj) \
     OBJECT_CHECK(CompareState, (obj), TYPE_COLO_COMPARE)
 
+static QTAILQ_HEAD(, CompareState) net_compares =
+       QTAILQ_HEAD_INITIALIZER(net_compares);
+
 #define COMPARE_READ_LEN_MAX NET_BUFSIZE
 #define MAX_QUEUE_SIZE 1024
 
@@ -41,6 +46,10 @@
 /* TODO: Should be configurable */
 #define REGULAR_PACKET_CHECK_MS 3000
 
+static QemuMutex event_mtx;
+static QemuCond event_complete_cond;
+static int event_unhandled_count;
+
 /*
  *  + CompareState ++
  *  |               |
@@ -87,6 +96,11 @@ typedef struct CompareState {
     IOThread *iothread;
     GMainContext *worker_context;
     QEMUTimer *packet_check_timer;
+
+    QEMUBH *event_bh;
+    enum colo_event event;
+
+    QTAILQ_ENTRY(CompareState) next;
 } CompareState;
 
 typedef struct CompareClass {
@@ -736,6 +750,25 @@ static void check_old_packet_regular(void *opaque)
                 REGULAR_PACKET_CHECK_MS);
 }
 
+/* Public API, Used for COLO frame to notify compare event */
+void colo_notify_compares_event(void *opaque, int event, Error **errp)
+{
+    CompareState *s;
+
+    qemu_mutex_lock(&event_mtx);
+    QTAILQ_FOREACH(s, &net_compares, next) {
+        s->event = event;
+        qemu_bh_schedule(s->event_bh);
+        event_unhandled_count++;
+    }
+    /* Wait all compare threads to finish handling this event */
+    while (event_unhandled_count > 0) {
+        qemu_cond_wait(&event_complete_cond, &event_mtx);
+    }
+
+    qemu_mutex_unlock(&event_mtx);
+}
+
 static void colo_compare_timer_init(CompareState *s)
 {
     AioContext *ctx = iothread_get_aio_context(s->iothread);
@@ -756,6 +789,30 @@ static void colo_compare_timer_del(CompareState *s)
     }
  }
 
+static void colo_flush_packets(void *opaque, void *user_data);
+
+static void colo_compare_handle_event(void *opaque)
+{
+    CompareState *s = opaque;
+
+    switch (s->event) {
+    case COLO_EVENT_CHECKPOINT:
+        g_queue_foreach(&s->conn_list, colo_flush_packets, s);
+        break;
+    case COLO_EVENT_FAILOVER:
+        break;
+    default:
+        break;
+    }
+
+    assert(event_unhandled_count > 0);
+
+    qemu_mutex_lock(&event_mtx);
+    event_unhandled_count--;
+    qemu_cond_broadcast(&event_complete_cond);
+    qemu_mutex_unlock(&event_mtx);
+}
+
 static void colo_compare_iothread(CompareState *s)
 {
     object_ref(OBJECT(s->iothread));
@@ -769,6 +826,7 @@ static void colo_compare_iothread(CompareState *s)
                              s, s->worker_context, true);
 
     colo_compare_timer_init(s);
+    s->event_bh = qemu_bh_new(colo_compare_handle_event, s);
 }
 
 static char *compare_get_pri_indev(Object *obj, Error **errp)
@@ -926,8 +984,13 @@ static void colo_compare_complete(UserCreatable *uc, Error **errp)
     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s->vnet_hdr);
     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, s->vnet_hdr);
 
+    QTAILQ_INSERT_TAIL(&net_compares, s, next);
+
     g_queue_init(&s->conn_list);
 
+    qemu_mutex_init(&event_mtx);
+    qemu_cond_init(&event_complete_cond);
+
     s->connection_track_table = g_hash_table_new_full(connection_key_hash,
                                                       connection_key_equal,
                                                       g_free,
@@ -990,6 +1053,7 @@ static void colo_compare_init(Object *obj)
 static void colo_compare_finalize(Object *obj)
 {
     CompareState *s = COLO_COMPARE(obj);
+    CompareState *tmp = NULL;
 
     qemu_chr_fe_deinit(&s->chr_pri_in, false);
     qemu_chr_fe_deinit(&s->chr_sec_in, false);
@@ -997,6 +1061,16 @@ static void colo_compare_finalize(Object *obj)
     if (s->iothread) {
         colo_compare_timer_del(s);
     }
+
+    qemu_bh_delete(s->event_bh);
+
+    QTAILQ_FOREACH(tmp, &net_compares, next) {
+        if (tmp == s) {
+            QTAILQ_REMOVE(&net_compares, s, next);
+            break;
+        }
+    }
+
     /* Release all unhandled packets after compare thead exited */
     g_queue_foreach(&s->conn_list, colo_flush_packets, s);
 
@@ -1009,6 +1083,10 @@ static void colo_compare_finalize(Object *obj)
     if (s->iothread) {
         object_unref(OBJECT(s->iothread));
     }
+
+    qemu_mutex_destroy(&event_mtx);
+    qemu_cond_destroy(&event_complete_cond);
+
     g_free(s->pri_indev);
     g_free(s->sec_indev);
     g_free(s->outdev);