use inet_listen()/inet_connect() to support ipv6 migration

Use help functions in qemu-socket.c for tcp migration,
which already support ipv6 addresses.

Currently errp will be set to UNDEFINED_ERROR when migration fails,
qemu would output "migration failed: ...", and current user can
see a message("An undefined error has occurred") in monitor.

This patch changed tcp_start_outgoing_migration()/inet_connect()
/inet_connect_opts(), socket error would be passed back,
then current user can see a meaningful err message in monitor.

Qemu will exit if listening fails, so output socket error
to qemu stderr.

For IPv6 brackets must be mandatory if you require a port.
Referencing to RFC5952, the recommended format is:
  [2312::8274]:5200

test status: Successed
listen side: qemu-kvm .... -incoming tcp:[2312::8274]:5200
client side: qemu-kvm ...
             (qemu) migrate -d tcp:[2312::8274]:5200

Signed-off-by: Amos Kong <akong@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/migration.c b/migration.c
index f9e968ee2a..3f485d33a5 100644
--- a/migration.c
+++ b/migration.c
@@ -60,13 +60,13 @@ static MigrationState *migrate_get_current(void)
     return &current_migration;
 }
 
-int qemu_start_incoming_migration(const char *uri)
+int qemu_start_incoming_migration(const char *uri, Error **errp)
 {
     const char *p;
     int ret;
 
     if (strstart(uri, "tcp:", &p))
-        ret = tcp_start_incoming_migration(p);
+        ret = tcp_start_incoming_migration(p, errp);
 #if !defined(WIN32)
     else if (strstart(uri, "exec:", &p))
         ret =  exec_start_incoming_migration(p);
@@ -414,7 +414,7 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
     s = migrate_init(blk, inc);
 
     if (strstart(uri, "tcp:", &p)) {
-        ret = tcp_start_outgoing_migration(s, p);
+        ret = tcp_start_outgoing_migration(s, p, errp);
 #if !defined(WIN32)
     } else if (strstart(uri, "exec:", &p)) {
         ret = exec_start_outgoing_migration(s, p);
@@ -429,9 +429,11 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
     }
 
     if (ret < 0) {
-        DPRINTF("migration failed: %s\n", strerror(-ret));
-        /* FIXME: we should return meaningful errors */
-        error_set(errp, QERR_UNDEFINED_ERROR);
+        if (!error_is_set(errp)) {
+            DPRINTF("migration failed: %s\n", strerror(-ret));
+            /* FIXME: we should return meaningful errors */
+            error_set(errp, QERR_UNDEFINED_ERROR);
+        }
         return;
     }