Merge remote-tracking branch 'remotes/amit-migration/tags/migration-for-2.7-7' into staging

Migration:
 - couple of bug fixes
 - couple of typo fixes

# gpg: Signature made Thu 11 Aug 2016 12:36:00 BST
# gpg:                using RSA key 0xEB0B4DFC657EF670
# gpg: Good signature from "Amit Shah <amit@amitshah.net>"
# gpg:                 aka "Amit Shah <amit@kernel.org>"
# gpg:                 aka "Amit Shah <amitshah@gmx.net>"
# Primary key fingerprint: 48CA 3722 5FE7 F4A8 B337  2735 1E9A 3B5F 8540 83B6
#      Subkey fingerprint: CC63 D332 AB8F 4617 4529  6534 EB0B 4DFC 657E F670

* remotes/amit-migration/tags/migration-for-2.7-7:
  migration/socket: fix typo in file header
  migration: fix live migration failure with compression
  migration: mmap error check fix
  migration/ram: fix typo
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

migration/postcopy-ram.c

@@ -604,7 +604,8 @@ void *postcopy_get_tmp_page(MigrationIncomingState *mis)
         mis->postcopy_tmp_page = mmap(NULL, getpagesize(),
                              PROT_READ | PROT_WRITE, MAP_PRIVATE |
                              MAP_ANONYMOUS, -1, 0);
-        if (!mis->postcopy_tmp_page) {
+        if (mis->postcopy_tmp_page == MAP_FAILED) {
+            mis->postcopy_tmp_page = NULL;
             error_report("%s: %s", __func__, strerror(errno));
             return NULL;
         }

migration/qemu-file.c

@@ -668,6 +668,7 @@ int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src)
         len = f_src->buf_index;
         qemu_put_buffer(f_des, f_src->buf, f_src->buf_index);
         f_src->buf_index = 0;
+        f_src->iovcnt = 0;
     }
     return len;
 }

migration/ram.c

@@ -375,8 +375,8 @@ void migrate_compress_threads_create(void)
     qemu_cond_init(&comp_done_cond);
     qemu_mutex_init(&comp_done_lock);
     for (i = 0; i < thread_count; i++) {
-        /* com_param[i].file is just used as a dummy buffer to save data, set
-         * it's ops to empty.
+        /* comp_param[i].file is just used as a dummy buffer to save data,
+         * set its ops to empty.
          */
         comp_param[i].file = qemu_fopen_ops(NULL, &empty_ops);
         comp_param[i].done = true;

migration/socket.c

 /*
- * QEMU live migration via Unix Domain Sockets
+ * QEMU live migration via socket
  *
  * Copyright Red Hat, Inc. 2009-2016
  *
@@ -94,10 +94,12 @@ static void socket_start_outgoing_migration(MigrationState *s,
 {
     QIOChannelSocket *sioc = qio_channel_socket_new();
     struct SocketConnectData *data = g_new0(struct SocketConnectData, 1);
+
     data->s = s;
     if (saddr->type == SOCKET_ADDRESS_KIND_INET) {
         data->hostname = g_strdup(saddr->u.inet.data->host);
     }
+
     qio_channel_socket_connect_async(sioc,
                                      saddr,
                                      socket_outgoing_migration,