diff mbox series

[V4,18/19] migration-test: cpr-transfer

Message ID 1733145611-62315-19-git-send-email-steven.sistare@oracle.com (mailing list archive)
State New, archived
Headers show
Series Live update: cpr-transfer | expand

Commit Message

Steven Sistare Dec. 2, 2024, 1:20 p.m. UTC
Add a migration test for cpr-transfer mode.  Defer the connection to the
target monitor, else the test hangs because in cpr-transfer mode QEMU does
not listen for monitor connections until we send the migrate command to
source QEMU.

To test -incoming defer, send a migrate incoming command to the target,
after sending the migrate command to the source, as required by
cpr-transfer mode.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 tests/qtest/migration-test.c | 72 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 71 insertions(+), 1 deletion(-)

Comments

Steven Sistare Dec. 18, 2024, 9:03 p.m. UTC | #1
If someone is bored, this needs review, else let it ride until V5.

- Steve

On 12/2/2024 8:20 AM, Steve Sistare wrote:
> Add a migration test for cpr-transfer mode.  Defer the connection to the
> target monitor, else the test hangs because in cpr-transfer mode QEMU does
> not listen for monitor connections until we send the migrate command to
> source QEMU.
> 
> To test -incoming defer, send a migrate incoming command to the target,
> after sending the migrate command to the source, as required by
> cpr-transfer mode.
> 
> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
> ---
>   tests/qtest/migration-test.c | 72 +++++++++++++++++++++++++++++++++++++++++++-
>   1 file changed, 71 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
> index 8bc665d..4eb641c 100644
> --- a/tests/qtest/migration-test.c
> +++ b/tests/qtest/migration-test.c
> @@ -1729,6 +1729,7 @@ static void test_precopy_common(MigrateCommon *args)
>   {
>       QTestState *from, *to;
>       void *data_hook = NULL;
> +    const char *connect_uri;
>   
>       if (test_migrate_start(&from, &to, args->listen_uri, &args->start)) {
>           return;
> @@ -1766,11 +1767,16 @@ static void test_precopy_common(MigrateCommon *args)
>           goto finish;
>       }
>   
> -    migrate_qmp(from, to, args->connect_uri, args->connect_channels, "{}");
> +    /* If has channels, then connect_uri is only used for listen defer */
> +    connect_uri = args->connect_channels ? NULL : args->connect_uri;
> +    migrate_qmp(from, to, connect_uri, args->connect_channels, "{}");
>   
>       if (args->start.defer_target_connect) {
>           qtest_connect_deferred(to);
>           qtest_qmp_handshake(to);
> +        if (!strcmp(args->listen_uri, "defer")) {
> +            migrate_incoming_qmp(to, args->connect_uri, "{}");
> +        }
>       }
>   
>       if (args->result != MIG_TEST_SUCCEED) {
> @@ -2415,6 +2421,66 @@ static void test_multifd_file_mapped_ram_fdset_dio(void)
>   }
>   #endif /* !_WIN32 */
>   
> +static void *test_mode_transfer_start(QTestState *from, QTestState *to)
> +{
> +    migrate_set_parameter_str(from, "mode", "cpr-transfer");
> +    return NULL;
> +}
> +
> +/*
> + * cpr-transfer mode cannot use the target monitor prior to starting the
> + * migration, and cannot connect synchronously to the monitor, so defer
> + * the target connection.
> + */
> +static void test_mode_transfer_common(bool incoming_defer)
> +{
> +    g_autofree char *cpr_path = g_strdup_printf("%s/cpr.sock", tmpfs);
> +    g_autofree char *mig_path = g_strdup_printf("%s/migsocket", tmpfs);
> +    g_autofree char *uri = g_strdup_printf("unix:%s", mig_path);
> +
> +    const char *opts = "-machine aux-ram-share=on -nodefaults";
> +    g_autofree char *opts_target = g_strdup_printf(
> +        "-incoming \\{\\\'channel-type\\\':\\\'cpr\\\',"
> +        "\\\'addr\\\':\\{\\\'transport\\\':\\\'socket\\\',"
> +        "\\\'type\\\':\\\'unix\\\',\\\'path\\\':\\\'%s\\\'\\}\\} %s",
> +        cpr_path, opts);
> +
> +    g_autofree char *channels = g_strdup_printf(
> +        "[ { 'channel-type': 'main',"
> +        "    'addr': { 'transport': 'socket',"
> +        "              'type': 'unix',"
> +        "              'path': '%s' } },"
> +        "  { 'channel-type': 'cpr',"
> +        "    'addr': { 'transport': 'socket',"
> +        "              'type': 'unix',"
> +        "              'path': '%s' } } ]",
> +        mig_path, cpr_path);
> +
> +    MigrateCommon args = {
> +        .start.opts_source = opts,
> +        .start.opts_target = opts_target,
> +        .start.defer_target_connect = true,
> +        .start.memory_backend = "-object memory-backend-memfd,id=pc.ram,size=%s"
> +                                " -machine memory-backend=pc.ram",
> +        .listen_uri = incoming_defer ? "defer" : uri,
> +        .connect_uri = incoming_defer ? uri : NULL,
> +        .connect_channels = channels,
> +        .start_hook = test_mode_transfer_start,
> +    };
> +
> +    test_precopy_common(&args);
> +}
> +
> +static void test_mode_transfer(void)
> +{
> +    test_mode_transfer_common(NULL);
> +}
> +
> +static void test_mode_transfer_defer(void)
> +{
> +    test_mode_transfer_common(true);
> +}
> +
>   static void test_precopy_tcp_plain(void)
>   {
>       MigrateCommon args = {
> @@ -3905,6 +3971,10 @@ int main(int argc, char **argv)
>           migration_test_add("/migration/mode/reboot", test_mode_reboot);
>       }
>   
> +    migration_test_add("/migration/mode/transfer", test_mode_transfer);
> +    migration_test_add("/migration/mode/transfer/defer",
> +                       test_mode_transfer_defer);
> +
>       migration_test_add("/migration/precopy/file/mapped-ram",
>                          test_precopy_file_mapped_ram);
>       migration_test_add("/migration/precopy/file/mapped-ram/live",
Peter Xu Dec. 19, 2024, 4:56 p.m. UTC | #2
On Mon, Dec 02, 2024 at 05:20:10AM -0800, Steve Sistare wrote:
> Add a migration test for cpr-transfer mode.  Defer the connection to the
> target monitor, else the test hangs because in cpr-transfer mode QEMU does
> not listen for monitor connections until we send the migrate command to
> source QEMU.
> 
> To test -incoming defer, send a migrate incoming command to the target,
> after sending the migrate command to the source, as required by
> cpr-transfer mode.
> 
> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
> ---
>  tests/qtest/migration-test.c | 72 +++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 71 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
> index 8bc665d..4eb641c 100644
> --- a/tests/qtest/migration-test.c
> +++ b/tests/qtest/migration-test.c
> @@ -1729,6 +1729,7 @@ static void test_precopy_common(MigrateCommon *args)
>  {
>      QTestState *from, *to;
>      void *data_hook = NULL;
> +    const char *connect_uri;
>  
>      if (test_migrate_start(&from, &to, args->listen_uri, &args->start)) {
>          return;
> @@ -1766,11 +1767,16 @@ static void test_precopy_common(MigrateCommon *args)
>          goto finish;
>      }
>  
> -    migrate_qmp(from, to, args->connect_uri, args->connect_channels, "{}");
> +    /* If has channels, then connect_uri is only used for listen defer */
> +    connect_uri = args->connect_channels ? NULL : args->connect_uri;
> +    migrate_qmp(from, to, connect_uri, args->connect_channels, "{}");

This smells like abuse.

If the test case sets connect_uri only because of below...

>  
>      if (args->start.defer_target_connect) {
>          qtest_connect_deferred(to);
>          qtest_qmp_handshake(to);
> +        if (!strcmp(args->listen_uri, "defer")) {
> +            migrate_incoming_qmp(to, args->connect_uri, "{}");

... here, then IMHO it's abusing connect_uri to start service incoming
ports.

We do have solution for "delay" incoming, right?   Shouldn't we use
migrate_get_connect_uri() instead, then never set connect_uri in
cpr-transfer tests?

> +        }
>      }
>  
>      if (args->result != MIG_TEST_SUCCEED) {
> @@ -2415,6 +2421,66 @@ static void test_multifd_file_mapped_ram_fdset_dio(void)
>  }
>  #endif /* !_WIN32 */
>  
> +static void *test_mode_transfer_start(QTestState *from, QTestState *to)
> +{
> +    migrate_set_parameter_str(from, "mode", "cpr-transfer");
> +    return NULL;
> +}
> +
> +/*
> + * cpr-transfer mode cannot use the target monitor prior to starting the
> + * migration, and cannot connect synchronously to the monitor, so defer
> + * the target connection.
> + */
> +static void test_mode_transfer_common(bool incoming_defer)
> +{
> +    g_autofree char *cpr_path = g_strdup_printf("%s/cpr.sock", tmpfs);
> +    g_autofree char *mig_path = g_strdup_printf("%s/migsocket", tmpfs);
> +    g_autofree char *uri = g_strdup_printf("unix:%s", mig_path);
> +
> +    const char *opts = "-machine aux-ram-share=on -nodefaults";
> +    g_autofree char *opts_target = g_strdup_printf(
> +        "-incoming \\{\\\'channel-type\\\':\\\'cpr\\\',"
> +        "\\\'addr\\\':\\{\\\'transport\\\':\\\'socket\\\',"
> +        "\\\'type\\\':\\\'unix\\\',\\\'path\\\':\\\'%s\\\'\\}\\} %s",
> +        cpr_path, opts);

Nobody will be able to change this easily.. Maybe use g_strescape()?

> +
> +    g_autofree char *channels = g_strdup_printf(
> +        "[ { 'channel-type': 'main',"
> +        "    'addr': { 'transport': 'socket',"
> +        "              'type': 'unix',"
> +        "              'path': '%s' } },"
> +        "  { 'channel-type': 'cpr',"
> +        "    'addr': { 'transport': 'socket',"
> +        "              'type': 'unix',"
> +        "              'path': '%s' } } ]",
> +        mig_path, cpr_path);
> +
> +    MigrateCommon args = {
> +        .start.opts_source = opts,
> +        .start.opts_target = opts_target,
> +        .start.defer_target_connect = true,
> +        .start.memory_backend = "-object memory-backend-memfd,id=pc.ram,size=%s"
> +                                " -machine memory-backend=pc.ram",
> +        .listen_uri = incoming_defer ? "defer" : uri,
> +        .connect_uri = incoming_defer ? uri : NULL,
> +        .connect_channels = channels,
> +        .start_hook = test_mode_transfer_start,
> +    };
> +
> +    test_precopy_common(&args);
> +}
> +
> +static void test_mode_transfer(void)
> +{
> +    test_mode_transfer_common(NULL);
> +}
> +
> +static void test_mode_transfer_defer(void)
> +{
> +    test_mode_transfer_common(true);
> +}
> +
>  static void test_precopy_tcp_plain(void)
>  {
>      MigrateCommon args = {
> @@ -3905,6 +3971,10 @@ int main(int argc, char **argv)
>          migration_test_add("/migration/mode/reboot", test_mode_reboot);
>      }
>  
> +    migration_test_add("/migration/mode/transfer", test_mode_transfer);
> +    migration_test_add("/migration/mode/transfer/defer",
> +                       test_mode_transfer_defer);
> +
>      migration_test_add("/migration/precopy/file/mapped-ram",
>                         test_precopy_file_mapped_ram);
>      migration_test_add("/migration/precopy/file/mapped-ram/live",
> -- 
> 1.8.3.1
>
Steven Sistare Dec. 19, 2024, 10:34 p.m. UTC | #3
On 12/19/2024 11:56 AM, Peter Xu wrote:
> On Mon, Dec 02, 2024 at 05:20:10AM -0800, Steve Sistare wrote:
>> Add a migration test for cpr-transfer mode.  Defer the connection to the
>> target monitor, else the test hangs because in cpr-transfer mode QEMU does
>> not listen for monitor connections until we send the migrate command to
>> source QEMU.
>>
>> To test -incoming defer, send a migrate incoming command to the target,
>> after sending the migrate command to the source, as required by
>> cpr-transfer mode.
>>
>> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
>> ---
>>   tests/qtest/migration-test.c | 72 +++++++++++++++++++++++++++++++++++++++++++-
>>   1 file changed, 71 insertions(+), 1 deletion(-)
>>
>> diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
>> index 8bc665d..4eb641c 100644
>> --- a/tests/qtest/migration-test.c
>> +++ b/tests/qtest/migration-test.c
>> @@ -1729,6 +1729,7 @@ static void test_precopy_common(MigrateCommon *args)
>>   {
>>       QTestState *from, *to;
>>       void *data_hook = NULL;
>> +    const char *connect_uri;
>>   
>>       if (test_migrate_start(&from, &to, args->listen_uri, &args->start)) {
>>           return;
>> @@ -1766,11 +1767,16 @@ static void test_precopy_common(MigrateCommon *args)
>>           goto finish;
>>       }
>>   
>> -    migrate_qmp(from, to, args->connect_uri, args->connect_channels, "{}");
>> +    /* If has channels, then connect_uri is only used for listen defer */
>> +    connect_uri = args->connect_channels ? NULL : args->connect_uri;
>> +    migrate_qmp(from, to, connect_uri, args->connect_channels, "{}");
> 
> This smells like abuse.
> 
> If the test case sets connect_uri only because of below...
> 
>>   
>>       if (args->start.defer_target_connect) {
>>           qtest_connect_deferred(to);
>>           qtest_qmp_handshake(to);
>> +        if (!strcmp(args->listen_uri, "defer")) {
>> +            migrate_incoming_qmp(to, args->connect_uri, "{}");
> 
> ... here, then IMHO it's abusing connect_uri to start service incoming
> ports.
> 
> We do have solution for "delay" incoming, right?   Shouldn't we use
> migrate_get_connect_uri() instead, then never set connect_uri in
> cpr-transfer tests?

We cannot use migrate_get_connect_uri() to get the URI to pass to
migrate_incoming_qmp, because the migrate_incoming_qmp sets the URI
returned by query-migrate.  chicken-and-egg problem.

I'll add channels support to migrate_incoming_qmp, like migrate_qmp.
The cpr-transfer test will set listen_uri and connect_channels but
will not set connect_uri.

>> +        }
>>       }
>>   
>>       if (args->result != MIG_TEST_SUCCEED) {
>> @@ -2415,6 +2421,66 @@ static void test_multifd_file_mapped_ram_fdset_dio(void)
>>   }
>>   #endif /* !_WIN32 */
>>   
>> +static void *test_mode_transfer_start(QTestState *from, QTestState *to)
>> +{
>> +    migrate_set_parameter_str(from, "mode", "cpr-transfer");
>> +    return NULL;
>> +}
>> +
>> +/*
>> + * cpr-transfer mode cannot use the target monitor prior to starting the
>> + * migration, and cannot connect synchronously to the monitor, so defer
>> + * the target connection.
>> + */
>> +static void test_mode_transfer_common(bool incoming_defer)
>> +{
>> +    g_autofree char *cpr_path = g_strdup_printf("%s/cpr.sock", tmpfs);
>> +    g_autofree char *mig_path = g_strdup_printf("%s/migsocket", tmpfs);
>> +    g_autofree char *uri = g_strdup_printf("unix:%s", mig_path);
>> +
>> +    const char *opts = "-machine aux-ram-share=on -nodefaults";
>> +    g_autofree char *opts_target = g_strdup_printf(
>> +        "-incoming \\{\\\'channel-type\\\':\\\'cpr\\\',"
>> +        "\\\'addr\\\':\\{\\\'transport\\\':\\\'socket\\\',"
>> +        "\\\'type\\\':\\\'unix\\\',\\\'path\\\':\\\'%s\\\'\\}\\} %s",
>> +        cpr_path, opts);
> 
> Nobody will be able to change this easily.. Maybe use g_strescape()?

Agreed. Fortunately incoming now accepts dotted keys after a suggestion from
Markus, so this can be:
   -incoming cpr,addr.transport=socket,addr.type=unix,addr.path=%s

- Steve

>> +
>> +    g_autofree char *channels = g_strdup_printf(
>> +        "[ { 'channel-type': 'main',"
>> +        "    'addr': { 'transport': 'socket',"
>> +        "              'type': 'unix',"
>> +        "              'path': '%s' } },"
>> +        "  { 'channel-type': 'cpr',"
>> +        "    'addr': { 'transport': 'socket',"
>> +        "              'type': 'unix',"
>> +        "              'path': '%s' } } ]",
>> +        mig_path, cpr_path);
>> +
>> +    MigrateCommon args = {
>> +        .start.opts_source = opts,
>> +        .start.opts_target = opts_target,
>> +        .start.defer_target_connect = true,
>> +        .start.memory_backend = "-object memory-backend-memfd,id=pc.ram,size=%s"
>> +                                " -machine memory-backend=pc.ram",
>> +        .listen_uri = incoming_defer ? "defer" : uri,
>> +        .connect_uri = incoming_defer ? uri : NULL,
>> +        .connect_channels = channels,
>> +        .start_hook = test_mode_transfer_start,
>> +    };
>> +
>> +    test_precopy_common(&args);
>> +}
>> +
>> +static void test_mode_transfer(void)
>> +{
>> +    test_mode_transfer_common(NULL);
>> +}
>> +
>> +static void test_mode_transfer_defer(void)
>> +{
>> +    test_mode_transfer_common(true);
>> +}
>> +
>>   static void test_precopy_tcp_plain(void)
>>   {
>>       MigrateCommon args = {
>> @@ -3905,6 +3971,10 @@ int main(int argc, char **argv)
>>           migration_test_add("/migration/mode/reboot", test_mode_reboot);
>>       }
>>   
>> +    migration_test_add("/migration/mode/transfer", test_mode_transfer);
>> +    migration_test_add("/migration/mode/transfer/defer",
>> +                       test_mode_transfer_defer);
>> +
>>       migration_test_add("/migration/precopy/file/mapped-ram",
>>                          test_precopy_file_mapped_ram);
>>       migration_test_add("/migration/precopy/file/mapped-ram/live",
>> -- 
>> 1.8.3.1
>>
>
Peter Xu Dec. 20, 2024, 3:41 p.m. UTC | #4
On Thu, Dec 19, 2024 at 05:34:59PM -0500, Steven Sistare wrote:
> > > @@ -1766,11 +1767,16 @@ static void test_precopy_common(MigrateCommon *args)
> > >           goto finish;
> > >       }
> > > -    migrate_qmp(from, to, args->connect_uri, args->connect_channels, "{}");
> > > +    /* If has channels, then connect_uri is only used for listen defer */
> > > +    connect_uri = args->connect_channels ? NULL : args->connect_uri;
> > > +    migrate_qmp(from, to, connect_uri, args->connect_channels, "{}");
> > 
> > This smells like abuse.
> > 
> > If the test case sets connect_uri only because of below...
> > 
> > >       if (args->start.defer_target_connect) {
> > >           qtest_connect_deferred(to);
> > >           qtest_qmp_handshake(to);
> > > +        if (!strcmp(args->listen_uri, "defer")) {
> > > +            migrate_incoming_qmp(to, args->connect_uri, "{}");
> > 
> > ... here, then IMHO it's abusing connect_uri to start service incoming
> > ports.
> > 
> > We do have solution for "delay" incoming, right?   Shouldn't we use
> > migrate_get_connect_uri() instead, then never set connect_uri in
> > cpr-transfer tests?
> 
> We cannot use migrate_get_connect_uri() to get the URI to pass to
> migrate_incoming_qmp, because the migrate_incoming_qmp sets the URI
> returned by query-migrate.  chicken-and-egg problem.

Oh yes, stupid me.

> 
> I'll add channels support to migrate_incoming_qmp, like migrate_qmp.
> The cpr-transfer test will set listen_uri and connect_channels but
> will not set connect_uri.

That's still a lightweight abuse, but better than connect_uri indeed.

Hopefully cpr is the only one that uses defer_target_connect, so yeah we
can go with it at least for now..
diff mbox series

Patch

diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index 8bc665d..4eb641c 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -1729,6 +1729,7 @@  static void test_precopy_common(MigrateCommon *args)
 {
     QTestState *from, *to;
     void *data_hook = NULL;
+    const char *connect_uri;
 
     if (test_migrate_start(&from, &to, args->listen_uri, &args->start)) {
         return;
@@ -1766,11 +1767,16 @@  static void test_precopy_common(MigrateCommon *args)
         goto finish;
     }
 
-    migrate_qmp(from, to, args->connect_uri, args->connect_channels, "{}");
+    /* If has channels, then connect_uri is only used for listen defer */
+    connect_uri = args->connect_channels ? NULL : args->connect_uri;
+    migrate_qmp(from, to, connect_uri, args->connect_channels, "{}");
 
     if (args->start.defer_target_connect) {
         qtest_connect_deferred(to);
         qtest_qmp_handshake(to);
+        if (!strcmp(args->listen_uri, "defer")) {
+            migrate_incoming_qmp(to, args->connect_uri, "{}");
+        }
     }
 
     if (args->result != MIG_TEST_SUCCEED) {
@@ -2415,6 +2421,66 @@  static void test_multifd_file_mapped_ram_fdset_dio(void)
 }
 #endif /* !_WIN32 */
 
+static void *test_mode_transfer_start(QTestState *from, QTestState *to)
+{
+    migrate_set_parameter_str(from, "mode", "cpr-transfer");
+    return NULL;
+}
+
+/*
+ * cpr-transfer mode cannot use the target monitor prior to starting the
+ * migration, and cannot connect synchronously to the monitor, so defer
+ * the target connection.
+ */
+static void test_mode_transfer_common(bool incoming_defer)
+{
+    g_autofree char *cpr_path = g_strdup_printf("%s/cpr.sock", tmpfs);
+    g_autofree char *mig_path = g_strdup_printf("%s/migsocket", tmpfs);
+    g_autofree char *uri = g_strdup_printf("unix:%s", mig_path);
+
+    const char *opts = "-machine aux-ram-share=on -nodefaults";
+    g_autofree char *opts_target = g_strdup_printf(
+        "-incoming \\{\\\'channel-type\\\':\\\'cpr\\\',"
+        "\\\'addr\\\':\\{\\\'transport\\\':\\\'socket\\\',"
+        "\\\'type\\\':\\\'unix\\\',\\\'path\\\':\\\'%s\\\'\\}\\} %s",
+        cpr_path, opts);
+
+    g_autofree char *channels = g_strdup_printf(
+        "[ { 'channel-type': 'main',"
+        "    'addr': { 'transport': 'socket',"
+        "              'type': 'unix',"
+        "              'path': '%s' } },"
+        "  { 'channel-type': 'cpr',"
+        "    'addr': { 'transport': 'socket',"
+        "              'type': 'unix',"
+        "              'path': '%s' } } ]",
+        mig_path, cpr_path);
+
+    MigrateCommon args = {
+        .start.opts_source = opts,
+        .start.opts_target = opts_target,
+        .start.defer_target_connect = true,
+        .start.memory_backend = "-object memory-backend-memfd,id=pc.ram,size=%s"
+                                " -machine memory-backend=pc.ram",
+        .listen_uri = incoming_defer ? "defer" : uri,
+        .connect_uri = incoming_defer ? uri : NULL,
+        .connect_channels = channels,
+        .start_hook = test_mode_transfer_start,
+    };
+
+    test_precopy_common(&args);
+}
+
+static void test_mode_transfer(void)
+{
+    test_mode_transfer_common(NULL);
+}
+
+static void test_mode_transfer_defer(void)
+{
+    test_mode_transfer_common(true);
+}
+
 static void test_precopy_tcp_plain(void)
 {
     MigrateCommon args = {
@@ -3905,6 +3971,10 @@  int main(int argc, char **argv)
         migration_test_add("/migration/mode/reboot", test_mode_reboot);
     }
 
+    migration_test_add("/migration/mode/transfer", test_mode_transfer);
+    migration_test_add("/migration/mode/transfer/defer",
+                       test_mode_transfer_defer);
+
     migration_test_add("/migration/precopy/file/mapped-ram",
                        test_precopy_file_mapped_ram);
     migration_test_add("/migration/precopy/file/mapped-ram/live",