spice migration: add QEVENT_SPICE_MIGRATE_COMPLETED

When migrating, libvirt queries the migration status, and upon migration
completions, it closes the migration src. On the other hand, when
migration is completed, spice transfers data from the src to destination
via the client. This data is required for keeping the spice session
after migration, without suffering from data loss and inconsistencies.
In order to allow this data transfer, we add QEVENT for signaling
libvirt that spice migration has completed, and libvirt needs to wait
for this event before quitting the src process.
Signed-off-by: NYonit Halperin <yhalperi@redhat.com>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

monitor.c

@@ -455,6 +455,7 @@ static const char *monitor_event_names[] = {
     [QEVENT_SUSPEND_DISK] = "SUSPEND_DISK",
     [QEVENT_WAKEUP] = "WAKEUP",
     [QEVENT_BALLOON_CHANGE] = "BALLOON_CHANGE",
+    [QEVENT_SPICE_MIGRATE_COMPLETED] = "SPICE_MIGRATE_COMPLETED",
 };
 QEMU_BUILD_BUG_ON(ARRAY_SIZE(monitor_event_names) != QEVENT_MAX)
 

monitor.h

@@ -43,6 +43,7 @@ typedef enum MonitorEvent {
     QEVENT_SUSPEND_DISK,
     QEVENT_WAKEUP,
     QEVENT_BALLOON_CHANGE,
+    QEVENT_SPICE_MIGRATE_COMPLETED,
 
     /* Add to 'monitor_event_names' array in monitor.c when
      * defining new events here */

ui/spice-core.c

@@ -285,6 +285,7 @@ typedef struct SpiceMigration {
 } SpiceMigration;
 
 static void migrate_connect_complete_cb(SpiceMigrateInstance *sin);
+static void migrate_end_complete_cb(SpiceMigrateInstance *sin);
 
 static const SpiceMigrateInterface migrate_interface = {
     .base.type = SPICE_INTERFACE_MIGRATION,
@@ -292,7 +293,7 @@ static const SpiceMigrateInterface migrate_interface = {
     .base.major_version = SPICE_INTERFACE_MIGRATION_MAJOR,
     .base.minor_version = SPICE_INTERFACE_MIGRATION_MINOR,
     .migrate_connect_complete = migrate_connect_complete_cb,
-    .migrate_end_complete = NULL,
+    .migrate_end_complete = migrate_end_complete_cb,
 };
 
 static SpiceMigration spice_migrate;
@@ -305,6 +306,11 @@ static void migrate_connect_complete_cb(SpiceMigrateInstance *sin)
     }
     sm->connect_complete.cb = NULL;
 }
+
+static void migrate_end_complete_cb(SpiceMigrateInstance *sin)
+{
+    monitor_protocol_event(QEVENT_SPICE_MIGRATE_COMPLETED, NULL);
+}
 #endif
 
 /* config string parsing */
@@ -489,6 +495,7 @@ static void migration_state_notifier(Notifier *notifier, void *data)
     } else if (migration_has_finished(s)) {
 #ifndef SPICE_INTERFACE_MIGRATION
         spice_server_migrate_switch(spice_server);
+        monitor_protocol_event(QEVENT_SPICE_MIGRATE_COMPLETED, NULL);
 #else
         spice_server_migrate_end(spice_server, true);
     } else if (migration_has_failed(s)) {