vfio/migration: Enhance VFIO migration state tracing

Move trace_vfio_migration_set_state() to the top of the function, add
recover_state to it, and add a new trace event to
vfio_migration_set_device_state().

This improves tracing of device state changes as state changes are now
also logged when vfio_migration_set_state() fails (covering recover
state and device reset transitions) and in no-op state transitions to
the same state.

Suggested-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

hw/vfio/migration.c

@@ -129,6 +129,9 @@ static void vfio_migration_set_device_state(VFIODevice *vbasedev,
 {
     VFIOMigration *migration = vbasedev->migration;
 
+    trace_vfio_migration_set_device_state(vbasedev->name,
+                                          mig_state_to_str(state));
+
     migration->device_state = state;
     vfio_migration_send_event(vbasedev);
 }
@@ -150,6 +153,9 @@ static int vfio_migration_set_state(VFIODevice *vbasedev,
         g_strdup_printf("%s: Failed setting device state to %s.",
                         vbasedev->name, mig_state_to_str(new_state));
 
+    trace_vfio_migration_set_state(vbasedev->name, mig_state_to_str(new_state),
+                                   mig_state_to_str(recover_state));
+
     if (new_state == migration->device_state) {
         return 0;
     }
@@ -209,8 +215,6 @@ static int vfio_migration_set_state(VFIODevice *vbasedev,
         migration->data_fd = mig_state->data_fd;
     }
 
-    trace_vfio_migration_set_state(vbasedev->name, mig_state_to_str(new_state));
-
     return 0;
 
 reset_device:

hw/vfio/trace-events

@@ -152,7 +152,8 @@ vfio_load_device_config_state(const char *name) " (%s)"
 vfio_load_state(const char *name, uint64_t data) " (%s) data 0x%"PRIx64
 vfio_load_state_device_data(const char *name, uint64_t data_size, int ret) " (%s) size 0x%"PRIx64" ret %d"
 vfio_migration_realize(const char *name) " (%s)"
-vfio_migration_set_state(const char *name, const char *state) " (%s) state %s"
+vfio_migration_set_device_state(const char *name, const char *state) " (%s) state %s"
+vfio_migration_set_state(const char *name, const char *new_state, const char *recover_state) " (%s) new state %s, recover state %s"
 vfio_migration_state_notifier(const char *name, int state) " (%s) state %d"
 vfio_save_block(const char *name, int data_size) " (%s) data_size %d"
 vfio_save_cleanup(const char *name) " (%s)"