migration/multifd: Add new migration test cases for legacy zero page checking.

Now that zero page checking is done on the multifd sender threads by
default, we still provide an option for backward compatibility. This
change adds a qtest migration test case to set the zero-page-detection
option to "legacy" and run multifd migration with zero page checking on the
migration main thread.

Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/20240311180015.3359271-8-hao.xiang@linux.dev
Signed-off-by: Peter Xu <peterx@redhat.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index 4023d808f9..71895abb7f 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -2772,6 +2772,24 @@ test_migrate_precopy_tcp_multifd_start(QTestState *from,
 }
 
 static void *
+test_migrate_precopy_tcp_multifd_start_zero_page_legacy(QTestState *from,
+                                                        QTestState *to)
+{
+    test_migrate_precopy_tcp_multifd_start_common(from, to, "none");
+    migrate_set_parameter_str(from, "zero-page-detection", "legacy");
+    return NULL;
+}
+
+static void *
+test_migration_precopy_tcp_multifd_start_no_zero_page(QTestState *from,
+                                                      QTestState *to)
+{
+    test_migrate_precopy_tcp_multifd_start_common(from, to, "none");
+    migrate_set_parameter_str(from, "zero-page-detection", "none");
+    return NULL;
+}
+
+static void *
 test_migrate_precopy_tcp_multifd_zlib_start(QTestState *from,
                                             QTestState *to)
 {
@@ -2812,6 +2830,36 @@ static void test_multifd_tcp_none(void)
     test_precopy_common(&args);
 }
 
+static void test_multifd_tcp_zero_page_legacy(void)
+{
+    MigrateCommon args = {
+        .listen_uri = "defer",
+        .start_hook = test_migrate_precopy_tcp_multifd_start_zero_page_legacy,
+        /*
+         * Multifd is more complicated than most of the features, it
+         * directly takes guest page buffers when sending, make sure
+         * everything will work alright even if guest page is changing.
+         */
+        .live = true,
+    };
+    test_precopy_common(&args);
+}
+
+static void test_multifd_tcp_no_zero_page(void)
+{
+    MigrateCommon args = {
+        .listen_uri = "defer",
+        .start_hook = test_migration_precopy_tcp_multifd_start_no_zero_page,
+        /*
+         * Multifd is more complicated than most of the features, it
+         * directly takes guest page buffers when sending, make sure
+         * everything will work alright even if guest page is changing.
+         */
+        .live = true,
+    };
+    test_precopy_common(&args);
+}
+
 static void test_multifd_tcp_zlib(void)
 {
     MigrateCommon args = {
@@ -3729,6 +3777,10 @@ int main(int argc, char **argv)
     }
     migration_test_add("/migration/multifd/tcp/plain/none",
                        test_multifd_tcp_none);
+    migration_test_add("/migration/multifd/tcp/plain/zero-page/legacy",
+                       test_multifd_tcp_zero_page_legacy);
+    migration_test_add("/migration/multifd/tcp/plain/zero-page/none",
+                       test_multifd_tcp_no_zero_page);
     migration_test_add("/migration/multifd/tcp/plain/cancel",
                        test_multifd_tcp_cancel);
     migration_test_add("/migration/multifd/tcp/plain/zlib",