[PATCH 1/2] net/colo-compare.c: Expose "compare_timeout" to user

[Zhang Chen <chen.zhang@intel.com >]

From: Zhang Chen <chen.zhang@intel.com>

The "compare_timeout" determines the max time to hold the primary net packet.
This patch expose the "compare_timeout", make user can
adjest this value according to the specific application scenario.

QMP command demo:
    { "execute": "qom-get",
         "arguments": { "path": "/objects/comp0",
                        "property": "compare_timeout" } }

    { "execute": "qom-set",
         "arguments": { "path": "/objects/comp0",
                        "property": "compare_timeout",
                        "value": 5000} }

Signed-off-by: Zhang Chen <chen.zhang@intel.com>
---
 net/colo-compare.c | 47 ++++++++++++++++++++++++++++++++++++++++++++--
 qemu-options.hx    |  5 +++--
 2 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/net/colo-compare.c b/net/colo-compare.c
index 7ee17f2cf8..ec09b2a524 100644
--- a/net/colo-compare.c
+++ b/net/colo-compare.c
@@ -50,6 +50,7 @@ static NotifierList colo_compare_notifiers =
 
 /* TODO: Should be configurable */
 #define REGULAR_PACKET_CHECK_MS 3000
+#define DEFAULT_TIME_OUT_MS 3000
 
 static QemuMutex event_mtx;
 static QemuCond event_complete_cond;
@@ -92,6 +93,7 @@ typedef struct CompareState {
     SocketReadState sec_rs;
     SocketReadState notify_rs;
     bool vnet_hdr;
+    uint32_t compare_timeout;
 
     /*
      * Record the connection that through the NIC
@@ -607,10 +609,9 @@ static int colo_old_packet_check_one_conn(Connection *conn,
                                           CompareState *s)
 {
     GList *result = NULL;
-    int64_t check_time = REGULAR_PACKET_CHECK_MS;
 
     result = g_queue_find_custom(&conn->primary_list,
-                                 &check_time,
+                                 &s->compare_timeout,
                                  (GCompareFunc)colo_old_packet_check_one);
 
     if (result) {
@@ -984,6 +985,39 @@ static void compare_set_notify_dev(Object *obj, const char *value, Error **errp)
     s->notify_dev = g_strdup(value);
 }
 
+static void compare_get_timeout(Object *obj, Visitor *v,
+                                const char *name, void *opaque,
+                                Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+    uint32_t value = s->compare_timeout;
+
+    visit_type_uint32(v, name, &value, errp);
+}
+
+static void compare_set_timeout(Object *obj, Visitor *v,
+                                const char *name, void *opaque,
+                                Error **errp)
+{
+    CompareState *s = COLO_COMPARE(obj);
+    Error *local_err = NULL;
+    uint32_t value;
+
+    visit_type_uint32(v, name, &value, &local_err);
+    if (local_err) {
+        goto out;
+    }
+    if (!value) {
+        error_setg(&local_err, "Property '%s.%s' requires a positive value",
+                   object_get_typename(obj), name);
+        goto out;
+    }
+    s->compare_timeout = value;
+
+out:
+    error_propagate(errp, local_err);
+}
+
 static void compare_pri_rs_finalize(SocketReadState *pri_rs)
 {
     CompareState *s = container_of(pri_rs, CompareState, pri_rs);
@@ -1090,6 +1124,11 @@ static void colo_compare_complete(UserCreatable *uc, Error **errp)
         return;
     }
 
+    if (!s->compare_timeout) {
+        /* Set default value to 3000 MS */
+        s->compare_timeout = DEFAULT_TIME_OUT_MS;
+    }
+
     if (find_and_check_chardev(&chr, s->pri_indev, errp) ||
         !qemu_chr_fe_init(&s->chr_pri_in, chr, errp)) {
         return;
@@ -1185,6 +1224,10 @@ static void colo_compare_init(Object *obj)
                             compare_get_notify_dev, compare_set_notify_dev,
                             NULL);
 
+    object_property_add(obj, "compare_timeout", "uint32",
+                        compare_get_timeout,
+                        compare_set_timeout, NULL, NULL, NULL);
+
     s->vnet_hdr = false;
     object_property_add_bool(obj, "vnet_hdr_support", compare_get_vnet_hdr,
                              compare_set_vnet_hdr, NULL);
diff --git a/qemu-options.hx b/qemu-options.hx
index ac315c1ac4..3832d0ae8a 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4598,7 +4598,7 @@ Dump the network traffic on netdev @var{dev} to the file specified by
 The file format is libpcap, so it can be analyzed with tools such as tcpdump
 or Wireshark.
 
-@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid},iothread=@var{id}[,vnet_hdr_support][,notify_dev=@var{id}]
+@item -object colo-compare,id=@var{id},primary_in=@var{chardevid},secondary_in=@var{chardevid},outdev=@var{chardevid},iothread=@var{id}[,vnet_hdr_support][,notify_dev=@var{id}][,compare_timeout=@var{ms}]
 
 Colo-compare gets packet from primary_in@var{chardevid} and secondary_in@var{chardevid}, than compare primary packet with
 secondary packet. If the packets are same, we will output primary
@@ -4606,7 +4606,8 @@ packet to outdev@var{chardevid}, else we will notify colo-frame
 do checkpoint and send primary packet to outdev@var{chardevid}.
 In order to improve efficiency, we need to put the task of comparison
 in another thread. If it has the vnet_hdr_support flag, colo compare
-will send/recv packet with vnet_hdr_len.
+will send/recv packet with vnet_hdr_len. The compare_timeout=@var{ms}
+determines the maximum time colo-compare wait for primary packet.
 If you want to use Xen COLO, will need the notify_dev to notify Xen
 colo-frame to do checkpoint.
 
-- 
2.17.1