[PATCH v10 11/31] tools/libxl: write checkpoint_state records into the stream

[Wen Congyang <wency@cn.fujitsu.com>]

write checkpoint_state records into the stream, used by both
primary and secondary to send colo context.

Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
---
 tools/libxl/libxl_internal.h     |  5 ++++
 tools/libxl/libxl_stream_write.c | 60 +++++++++++++++++++++++++++++++++++++++-
 2 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index e02e554..cdf6751 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -3056,6 +3056,7 @@ struct libxl__stream_write_state {
     bool running;
     bool in_checkpoint;
     bool sync_teardown;  /* Only used to coordinate shutdown on error path. */
+    bool in_checkpoint_state;
     libxl__save_helper_state shs;
 
     /* Main stream-writing data. */
@@ -3079,6 +3080,10 @@ _hidden void libxl__stream_write_start(libxl__egc *egc,
 _hidden void
 libxl__stream_write_start_checkpoint(libxl__egc *egc,
                                      libxl__stream_write_state *stream);
+_hidden void
+libxl__stream_write_checkpoint_state(libxl__egc *egc,
+                                     libxl__stream_write_state *stream,
+                                     libxl_sr_checkpoint_state *srcs);
 _hidden void libxl__stream_write_abort(libxl__egc *egc,
                                        libxl__stream_write_state *stream,
                                        int rc);
diff --git a/tools/libxl/libxl_stream_write.c b/tools/libxl/libxl_stream_write.c
index 5379126..8e0e57e 100644
--- a/tools/libxl/libxl_stream_write.c
+++ b/tools/libxl/libxl_stream_write.c
@@ -98,6 +98,12 @@ static void write_checkpoint_end_record(libxl__egc *egc,
 static void checkpoint_end_record_done(libxl__egc *egc,
                                        libxl__stream_write_state *stream);
 
+/* checkpoint state */
+static void write_checkpoint_state_done(libxl__egc *egc,
+                                        libxl__stream_write_state *stream);
+static void checkpoint_state_done(libxl__egc *egc,
+                                  libxl__stream_write_state *stream, int rc);
+
 /*----- Helpers -----*/
 
 static void write_done(libxl__egc *egc,
@@ -589,6 +595,21 @@ static void stream_complete(libxl__egc *egc,
         return;
     }
 
+    if (stream->in_checkpoint_state) {
+        assert(rc);
+
+        /*
+         * If an error is encountered while in a checkpoint, pass it
+         * back to libxc.  The failure will come back around to us via
+         * 1. normal stream
+         *    libxl__xc_domain_save_done()
+         * 2. back_channel stream
+         *    libxl__stream_write_abort()
+         */
+        checkpoint_state_done(egc, stream, rc);
+        return;
+    }
+
     stream_done(egc, stream, rc);
 }
 
@@ -596,6 +617,7 @@ static void stream_done(libxl__egc *egc,
                         libxl__stream_write_state *stream, int rc)
 {
     assert(stream->running);
+    assert(!stream->in_checkpoint_state);
     stream->running = false;
 
     if (stream->emu_carefd)
@@ -656,7 +678,43 @@ static void check_all_finished(libxl__egc *egc,
         libxl__save_helper_inuse(&stream->shs))
         return;
 
-    stream->completion_callback(egc, stream, stream->rc);
+    if (stream->completion_callback)
+        /* back channel stream doesn't have completion_callback() */
+        stream->completion_callback(egc, stream, stream->rc);
+}
+
+/*----- checkpoint state -----*/
+void libxl__stream_write_checkpoint_state(libxl__egc *egc,
+                                          libxl__stream_write_state *stream,
+                                          libxl_sr_checkpoint_state *srcs)
+{
+    struct libxl__sr_rec_hdr rec;
+
+    assert(stream->running);
+    assert(!stream->in_checkpoint);
+    assert(!stream->in_checkpoint_state);
+    stream->in_checkpoint_state = true;
+
+    FILLZERO(rec);
+    rec.type = REC_TYPE_CHECKPOINT_STATE;
+    rec.length = sizeof(*srcs);
+
+    setup_write(egc, stream, "checkpoint state", &rec,
+                srcs, write_checkpoint_state_done);
+}
+
+static void write_checkpoint_state_done(libxl__egc *egc,
+                                        libxl__stream_write_state *stream)
+{
+    checkpoint_state_done(egc, stream, 0);
+}
+
+static void checkpoint_state_done(libxl__egc *egc,
+                                  libxl__stream_write_state *stream, int rc)
+{
+    assert(stream->in_checkpoint_state);
+    stream->in_checkpoint_state = false;
+    stream->checkpoint_callback(egc, stream, rc);
 }
 
 /*
-- 
2.5.0