[PATCH V2 06/10] tests/qtest: migration events

[Steve Sistare]

Define a state object to capture events seen by migration tests, to allow
more events to be captured in a subsequent patch, and simplify event
checking in wait_for_migration_pass.  No functional change.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 tests/qtest/migration-helpers.c | 24 +++++----------
 tests/qtest/migration-helpers.h |  8 +++--
 tests/qtest/migration-test.c    | 68 +++++++++++++++++++----------------------
 3 files changed, 44 insertions(+), 56 deletions(-)

diff --git a/tests/qtest/migration-helpers.c b/tests/qtest/migration-helpers.c
index be00c52..b541108 100644
--- a/tests/qtest/migration-helpers.c
+++ b/tests/qtest/migration-helpers.c
@@ -23,26 +23,16 @@
  */
 #define MIGRATION_STATUS_WAIT_TIMEOUT 120
 
-bool migrate_watch_for_stop(QTestState *who, const char *name,
-                            QDict *event, void *opaque)
-{
-    bool *seen = opaque;
-
-    if (g_str_equal(name, "STOP")) {
-        *seen = true;
-        return true;
-    }
-
-    return false;
-}
-
-bool migrate_watch_for_resume(QTestState *who, const char *name,
+bool migrate_watch_for_events(QTestState *who, const char *name,
                               QDict *event, void *opaque)
 {
-    bool *seen = opaque;
+    QTestMigrationState *state = opaque;
 
-    if (g_str_equal(name, "RESUME")) {
-        *seen = true;
+    if (g_str_equal(name, "STOP")) {
+        state->stop_seen = true;
+        return true;
+    } else if (g_str_equal(name, "RESUME")) {
+        state->resume_seen = true;
         return true;
     }
 
diff --git a/tests/qtest/migration-helpers.h b/tests/qtest/migration-helpers.h
index 009e250..59fbb83 100644
--- a/tests/qtest/migration-helpers.h
+++ b/tests/qtest/migration-helpers.h
@@ -15,9 +15,11 @@
 
 #include "libqtest.h"
 
-bool migrate_watch_for_stop(QTestState *who, const char *name,
-                            QDict *event, void *opaque);
-bool migrate_watch_for_resume(QTestState *who, const char *name,
+typedef struct QTestMigrationState {
+    bool stop_seen, resume_seen;
+} QTestMigrationState;
+
+bool migrate_watch_for_events(QTestState *who, const char *name,
                               QDict *event, void *opaque);
 
 G_GNUC_PRINTF(3, 4)
diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index b0c355b..2dde3af 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -43,8 +43,8 @@
 unsigned start_address;
 unsigned end_address;
 static bool uffd_feature_thread_id;
-static bool got_src_stop;
-static bool got_dst_resume;
+static QTestMigrationState src_state;
+static QTestMigrationState dst_state;
 
 /*
  * Dirtylimit stop working if dirty page rate error
@@ -174,6 +174,13 @@ static void wait_for_serial(const char *side)
     } while (true);
 }
 
+static void wait_for_stop(QTestState *who, QTestMigrationState *state)
+{
+    if (!state->stop_seen) {
+        qtest_qmp_eventwait(who, "STOP");
+    }
+}
+
 /*
  * It's tricky to use qemu's migration event capability with qtest,
  * events suddenly appearing confuse the qmp()/hmp() responses.
@@ -221,21 +228,19 @@ static void read_blocktime(QTestState *who)
     qobject_unref(rsp_return);
 }
 
+/*
+ * Wait for two changes in the migration pass count, but bail if we stop.
+ */
 static void wait_for_migration_pass(QTestState *who)
 {
-    uint64_t initial_pass = get_migration_pass(who);
-    uint64_t pass;
+    uint64_t pass, prev_pass = 0, changes = 0;
 
-    /* Wait for the 1st sync */
-    while (!got_src_stop && !initial_pass) {
-        usleep(1000);
-        initial_pass = get_migration_pass(who);
-    }
-
-    do {
+    while (changes < 2 && !src_state.stop_seen) {
         usleep(1000);
         pass = get_migration_pass(who);
-    } while (pass == initial_pass && !got_src_stop);
+        changes += (pass != prev_pass);
+        prev_pass = pass;
+    }
 }
 
 static void check_guests_ram(QTestState *who)
@@ -487,10 +492,7 @@ static void migrate_postcopy_start(QTestState *from, 
QTestState *to)
 {
     qtest_qmp_assert_success(from, "{ 'execute': 'migrate-start-postcopy' }");
 
-    if (!got_src_stop) {
-        qtest_qmp_eventwait(from, "STOP");
-    }
-
+    wait_for_stop(from, &src_state);
     qtest_qmp_eventwait(to, "RESUME");
 }
 
@@ -617,8 +619,9 @@ static int test_migrate_start(QTestState **from, QTestState 
**to,
         }
     }
 
-    got_src_stop = false;
-    got_dst_resume = false;
+    dst_state = (QTestMigrationState) { };
+    src_state = (QTestMigrationState) { };
+
     bootpath = g_strdup_printf("%s/bootsect", tmpfs);
     if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
         /* the assembled x86 boot sector should be exactly one sector large */
@@ -705,8 +708,8 @@ static int test_migrate_start(QTestState **from, QTestState 
**to,
     if (!args->only_target) {
         *from = qtest_init(cmd_source);
         qtest_qmp_set_event_callback(*from,
-                                     migrate_watch_for_stop,
-                                     &got_src_stop);
+                                     migrate_watch_for_events,
+                                     &src_state);
     }
 
     cmd_target = g_strdup_printf("-accel kvm%s -accel tcg%s%s "
@@ -725,8 +728,8 @@ static int test_migrate_start(QTestState **from, QTestState 
**to,
                                  ignore_stderr);
     *to = qtest_init(cmd_target);
     qtest_qmp_set_event_callback(*to,
-                                 migrate_watch_for_resume,
-                                 &got_dst_resume);
+                                 migrate_watch_for_events,
+                                 &dst_state);
 
     /*
      * Remove shmem file immediately to avoid memory leak in test failed case.
@@ -1422,9 +1425,7 @@ static void test_precopy_common(MigrateCommon *args)
          */
         if (args->result == MIG_TEST_SUCCEED) {
             qtest_qmp_assert_success(from, "{ 'execute' : 'stop'}");
-            if (!got_src_stop) {
-                qtest_qmp_eventwait(from, "STOP");
-            }
+            wait_for_stop(from, &src_state);
             migrate_ensure_converge(from);
         }
     }
@@ -1463,9 +1464,8 @@ static void test_precopy_common(MigrateCommon *args)
              */
             wait_for_migration_complete(from);
 
-            if (!got_src_stop) {
-                qtest_qmp_eventwait(from, "STOP");
-            }
+            wait_for_stop(from, &src_state);
+
         } else {
             wait_for_migration_complete(from);
             /*
@@ -1478,7 +1478,7 @@ static void test_precopy_common(MigrateCommon *args)
             qtest_qmp_assert_success(to, "{ 'execute' : 'cont'}");
         }
 
-        if (!got_dst_resume) {
+        if (!dst_state.resume_seen) {
             qtest_qmp_eventwait(to, "RESUME");
         }
 
@@ -1596,9 +1596,7 @@ static void test_ignore_shared(void)
 
     wait_for_migration_pass(from);
 
-    if (!got_src_stop) {
-        qtest_qmp_eventwait(from, "STOP");
-    }
+    wait_for_stop(from, &src_state);
 
     qtest_qmp_eventwait(to, "RESUME");
 
@@ -2012,7 +2010,7 @@ static void test_migrate_auto_converge(void)
             break;
         }
         usleep(20);
-        g_assert_false(got_src_stop);
+        g_assert_false(src_state.stop_seen);
     } while (true);
     /* The first percentage of throttling should be at least init_pct */
     g_assert_cmpint(percentage, >=, init_pct);
@@ -2351,9 +2349,7 @@ static void test_multifd_tcp_cancel(void)
 
     wait_for_migration_pass(from);
 
-    if (!got_src_stop) {
-        qtest_qmp_eventwait(from, "STOP");
-    }
+    wait_for_stop(from, &src_state);
     qtest_qmp_eventwait(to2, "RESUME");
 
     wait_for_serial("dest_serial");
-- 
1.8.3.1