[Qemu-devel] [RFC PATCH 16/20] Introduce event_tap fucntions and ft_tranx_ready().

[Yoshiaki Tamura]

event_tap controls when to start ft transaction.  do_event_tap()
should be instered to the device emulators.
ft_tranx_ready() kicks the transaction.

Signed-off-by: Yoshiaki Tamura <address@hidden>
---
 migration.c   |   77 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 migration.h   |    2 +
 qemu-common.h |   19 ++++++++++++++
 3 files changed, 98 insertions(+), 0 deletions(-)

diff --git a/migration.c b/migration.c
index 4eed0b7..3cc47fc 100644
--- a/migration.c
+++ b/migration.c
@@ -39,6 +39,45 @@ static uint32_t max_throttle = (32 << 20);
 
 static MigrationState *current_migration;
 
+#ifdef CONFIG_FT_MODE
+static enum EVENT_TAP_STATE event_tap_state = EVENT_TAP_OFF;
+
+void event_tap_on(void)
+{
+    event_tap_state = EVENT_TAP_ON;
+}
+
+void event_tap_off(void)
+{
+    event_tap_state = EVENT_TAP_OFF;
+}
+
+void event_tap_suspend(void)
+{
+    if (event_tap_state == EVENT_TAP_ON)
+        event_tap_state = EVENT_TAP_SUSPEND;
+}
+
+void event_tap_resume(void)
+{
+    if (event_tap_state == EVENT_TAP_SUSPEND)
+        event_tap_state = EVENT_TAP_ON;
+}
+
+void do_event_tap(void)
+{
+    if (event_tap_state != EVENT_TAP_ON)
+        return;
+
+    if (ft_mode == FT_TRANSACTION || ft_mode == FT_INIT) {
+        if (ft_tranx_ready(current_migration) < 0) {
+            event_tap_off();
+            vm_start();
+        }
+    }
+}
+#endif
+
 void qemu_start_incoming_migration(const char *uri)
 {
     const char *p;
@@ -390,6 +429,44 @@ void migrate_fd_connect(FdMigrationState *s)
     migrate_fd_put_ready(s);
 }
 
+int ft_tranx_ready(void *opaque)
+{
+    FdMigrationState *s = migrate_to_fms(opaque);
+    int ret = -1;
+    
+    if (qemu_transaction_begin(s->file) < 0) {
+        fprintf(stderr, "tranx_begin failed\n");
+        goto error_out;
+    }
+
+    /* make the VM state consistent by flushing outstanding requests. */
+    vm_stop(0);
+    qemu_aio_flush();
+    bdrv_flush_all();
+
+    if (qemu_savevm_state_all(s->mon, s->file) < 0) {
+        fprintf(stderr, "savevm_state_all failed\n");
+        goto error_out;
+    }
+
+    if (qemu_transaction_commit(s->file) < 0) {
+        fprintf(stderr, "tranx_commit failed\n");
+        goto error_out;
+    }
+
+    ret = 0;
+    vm_start();
+
+    return ret;
+
+error_out:
+    ft_mode = FT_OFF;
+    qemu_savevm_state_cancel(s->mon, s->file);
+    migrate_fd_cleanup(s);
+
+    return ret;
+}
+
 void migrate_fd_put_ready(void *opaque)
 {
     FdMigrationState *s = opaque;
diff --git a/migration.h b/migration.h
index ddc1d42..41ee3fe 100644
--- a/migration.h
+++ b/migration.h
@@ -133,6 +133,8 @@ void migrate_fd_wait_for_unfreeze(void *opaque);
 
 int migrate_fd_close(void *opaque);
 
+int ft_tranx_ready(void *opaque);
+
 static inline FdMigrationState *migrate_to_fms(MigrationState *mig_state)
 {
     return container_of(mig_state, FdMigrationState, mig_state);
diff --git a/qemu-common.h b/qemu-common.h
index 0af30d2..5753af2 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -294,4 +294,23 @@ static inline uint8_t from_bcd(uint8_t val)
 
 #endif /* dyngen-exec.h hack */
 
+#ifdef CONFIG_FT_MODE
+enum EVENT_TAP_STATE {
+    EVENT_TAP_OFF,
+    EVENT_TAP_ON,
+    EVENT_TAP_SUSPEND,
+};
+void event_tap_on(void);
+void event_tap_off(void);
+void event_tap_suspend(void);
+void event_tap_resume(void);
+void do_event_tap(void);
+#else
+#define event_tap_on() do { } while (0)
+#define event_tap_off() do { } while (0)
+#define event_tap_suspend() do { } while (0)
+#define event_tap_resume() do { } while (0)
+#define do_event_tap() do { } while (0)
+#endif
+
 #endif
-- 
1.7.0.31.g1df487