net/announce: Add optional ID

Previously there was a single instance of the timer used by
monitor triggered announces, that's OK, but when combined with the
previous change that lets you have announces for subsets of interfaces
it's a bit restrictive if you want to do different things to different
interfaces.

Add an 'id' field to the announce, and maintain a list of the
timers based on id.

This allows you to for example:
    a) Start an announce going on interface eth0 for a long time
    b) Start an announce going on interface eth1 for a long time
    c) Kill the announce on eth0 while leaving eth1 going.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

hw/net/virtio-net.c

@@ -2360,7 +2360,7 @@ static int virtio_net_post_load_device(void *opaque, int version_id)
             timer_mod(n->announce_timer.tm,
                       qemu_clock_get_ms(n->announce_timer.type));
         } else {
-            qemu_announce_timer_del(&n->announce_timer);
+            qemu_announce_timer_del(&n->announce_timer, false);
         }
     }
 
@@ -2784,7 +2784,7 @@ static void virtio_net_device_unrealize(DeviceState *dev, Error **errp)
         virtio_net_del_queue(n, i);
     }
 
-    qemu_announce_timer_del(&n->announce_timer);
+    qemu_announce_timer_del(&n->announce_timer, false);
     g_free(n->vqs);
     qemu_del_nic(n->nic);
     virtio_net_rsc_cleanup(n);

include/net/announce.h

@@ -22,8 +22,12 @@ struct AnnounceTimer {
 /* Returns: update the timer to the next time point */
 int64_t qemu_announce_timer_step(AnnounceTimer *timer);
 
-/* Delete the underlying timer and other data */
-void qemu_announce_timer_del(AnnounceTimer *timer);
+/*
+ * Delete the underlying timer and other data
+ * If 'free_named' true and the timer is a named timer, then remove
+ * it from the list of named timers and free the AnnounceTimer itself.
+ */
+void qemu_announce_timer_del(AnnounceTimer *timer, bool free_named);
 
 /*
  * Under BQL/main thread

net/announce.c

@@ -15,6 +15,8 @@
 #include "qapi/qapi-commands-net.h"
 #include "trace.h"
 
+static GData *named_timers;
+
 int64_t qemu_announce_timer_step(AnnounceTimer *timer)
 {
     int64_t step;
@@ -31,8 +33,13 @@ int64_t qemu_announce_timer_step(AnnounceTimer *timer)
     return step;
 }
 
-void qemu_announce_timer_del(AnnounceTimer *timer)
+/*
+ * If 'free_named' is true, then remove the timer from the list
+ * and free the timer itself.
+ */
+void qemu_announce_timer_del(AnnounceTimer *timer, bool free_named)
 {
+    bool free_timer = false;
     if (timer->tm) {
         timer_del(timer->tm);
         timer_free(timer->tm);
@@ -40,6 +47,24 @@ void qemu_announce_timer_del(AnnounceTimer *timer)
     }
     qapi_free_strList(timer->params.interfaces);
     timer->params.interfaces = NULL;
+    if (free_named && timer->params.has_id) {
+        AnnounceTimer *list_timer;
+        /*
+         * Sanity check: There should only be one timer on the list with
+         * the id.
+         */
+        list_timer = g_datalist_get_data(&named_timers, timer->params.id);
+        assert(timer == list_timer);
+        free_timer = true;
+        g_datalist_remove_data(&named_timers, timer->params.id);
+    }
+    trace_qemu_announce_timer_del(free_named, free_timer, timer->params.id);
+    g_free(timer->params.id);
+    timer->params.id = NULL;
+
+    if (free_timer) {
+        g_free(timer);
+    }
 }
 
 /*
@@ -56,7 +81,7 @@ void qemu_announce_timer_reset(AnnounceTimer *timer,
      * We're under the BQL, so the current timer can't
      * be firing, so we should be able to delete it.
      */
-    qemu_announce_timer_del(timer);
+    qemu_announce_timer_del(timer, false);
 
     QAPI_CLONE_MEMBERS(AnnounceParameters, &timer->params, params);
     timer->round = params->rounds;
@@ -120,7 +145,8 @@ static void qemu_announce_self_iter(NICState *nic, void *opaque)
         skip = false;
     }
 
-    trace_qemu_announce_self_iter(nic->ncs->name,
+    trace_qemu_announce_self_iter(timer->params.has_id ? timer->params.id : "_",
+                                  nic->ncs->name,
                                   qemu_ether_ntoa(&nic->conf->macaddr), skip);
 
     if (!skip) {
@@ -143,7 +169,7 @@ static void qemu_announce_self_once(void *opaque)
     if (--timer->round) {
         qemu_announce_timer_step(timer);
     } else {
-        qemu_announce_timer_del(timer);
+        qemu_announce_timer_del(timer, true);
     }
 }
 
@@ -154,12 +180,24 @@ void qemu_announce_self(AnnounceTimer *timer, AnnounceParameters *params)
     if (params->rounds) {
         qemu_announce_self_once(timer);
     } else {
-        qemu_announce_timer_del(timer);
+        qemu_announce_timer_del(timer, true);
     }
 }
 
 void qmp_announce_self(AnnounceParameters *params, Error **errp)
 {
-    static AnnounceTimer announce_timer;
-    qemu_announce_self(&announce_timer, params);
+    AnnounceTimer *named_timer;
+    if (!params->has_id) {
+        params->id = g_strdup("");
+        params->has_id = true;
+    }
+
+    named_timer = g_datalist_get_data(&named_timers, params->id);
+
+    if (!named_timer) {
+        named_timer = g_new0(AnnounceTimer, 1);
+        g_datalist_set_data(&named_timers, params->id, named_timer);
+    }
+
+    qemu_announce_self(named_timer, params);
 }

net/trace-events

@@ -1,7 +1,8 @@
 # See docs/devel/tracing.txt for syntax documentation.
 
 # announce.c
-qemu_announce_self_iter(const char *name, const char *mac, int skip) "%s:%s skip: %d"
+qemu_announce_self_iter(const char *id, const char *name, const char *mac, int skip) "%s:%s:%s skip: %d"
+qemu_announce_timer_del(bool free_named, bool free_timer, char *id) "free named: %d free timer: %d id: %s"
 
 # vhost-user.c
 vhost_user_event(const char *chr, int event) "chr: %s got event: %d"

qapi/net.json

@@ -702,6 +702,10 @@
 # @interfaces: An optional list of interface names, which restricts the
 #        announcement to the listed interfaces. (Since 4.1)
 #
+# @id: A name to be used to identify an instance of announce-timers
+#        and to allow it to modified later.  Not for use as
+#        part of the migration parameters. (Since 4.1)
+#
 # Since: 4.0
 ##
 
@@ -710,7 +714,8 @@
             'max': 'int',
             'rounds': 'int',
             'step': 'int',
-            '*interfaces': ['str'] } }
+            '*interfaces': ['str'],
+            '*id' : 'str' } }
 
 ##
 # @announce-self:
@@ -725,7 +730,7 @@
 # -> { "execute": "announce-self",
 #      "arguments": {
 #          "initial": 50, "max": 550, "rounds": 10, "step": 50,
-#          "interfaces": ["vn2", "vn3"] } }
+#          "interfaces": ["vn2", "vn3"], "id": "bob" } }
 # <- { "return": {} }
 #
 # Since: 4.0