@@ -405,6 +405,7 @@ void libxl__domain_save(libxl__egc *egc, libxl__domain_save_state *dss)
dss->sws.ao = dss->ao;
dss->sws.dss = dss;
dss->sws.fd = dss->fd;
+ dss->sws.back_channel = false;
dss->sws.completion_callback = stream_done;
libxl__stream_write_start(egc, &dss->sws);
@@ -3042,6 +3042,7 @@ struct libxl__stream_write_state {
libxl__ao *ao;
libxl__domain_save_state *dss;
int fd;
+ bool back_channel;
void (*completion_callback)(libxl__egc *egc,
libxl__stream_write_state *sws,
int rc);
@@ -3053,6 +3054,7 @@ 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. */
@@ -3076,6 +3078,10 @@ _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);
@@ -49,6 +49,13 @@
* - if (hvm)
* - Emulator context record
* - Checkpoint end record
+ *
+ * For back channel stream:
+ * - libxl__stream_write_start()
+ * - Set up the stream to running state
+ *
+ * - Use libxl__stream_write_checkpoint_state to write the record. When the
+ * record is written out, call stream->checkpoint_callback() to return.
*/
/* Success/error/cleanup handling. */
@@ -91,6 +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,
@@ -225,6 +238,17 @@ void libxl__stream_write_start(libxl__egc *egc,
stream->running = true;
+ dc->ao = ao;
+ dc->readfd = -1;
+ dc->writewhat = "stream header";
+ dc->copywhat = "save v2 stream";
+ dc->writefd = stream->fd;
+ dc->maxsz = -1;
+ dc->callback = stream_header_done;
+
+ if (stream->back_channel)
+ return;
+
if (dss->type == LIBXL_DOMAIN_TYPE_HVM) {
stream->device_model_version =
libxl__device_model_version_running(gc, dss->domid);
@@ -249,14 +273,6 @@ void libxl__stream_write_start(libxl__egc *egc,
stream->emu_sub_hdr.index = 0;
}
- dc->ao = ao;
- dc->readfd = -1;
- dc->writewhat = "stream header";
- dc->copywhat = "save v2 stream";
- dc->writefd = stream->fd;
- dc->maxsz = -1;
- dc->callback = stream_header_done;
-
rc = libxl__datacopier_start(dc);
if (rc)
goto err;
@@ -279,6 +295,7 @@ void libxl__stream_write_start_checkpoint(libxl__egc *egc,
{
assert(stream->running);
assert(!stream->in_checkpoint);
+ assert(!stream->back_channel);
stream->in_checkpoint = true;
write_emulator_xenstore_record(egc, stream);
@@ -577,6 +594,21 @@ 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);
}
@@ -584,13 +616,24 @@ 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)
libxl__carefd_close(stream->emu_carefd);
free(stream->emu_body);
- check_all_finished(egc, stream, rc);
+ if (!stream->back_channel) {
+ /*
+ * 1. In stream_done(), stream->running is set to false, so
+ * the stream itself is not in use.
+ * 2. Write stream is a back channel stream, this means it
+ * is only used by secondary(restore side) to send records
+ * back, so it doesn't have save helper.
+ * So we don't need invoke check_all_finished here
+ */
+ check_all_finished(egc, stream, rc);
+ }
}
static void checkpoint_done(libxl__egc *egc,
@@ -642,7 +685,43 @@ 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);
}
/*