Import QEMU upstream snapshot d2e570c

Upstream: https://gitlab.com/qemu-project/qemu.git

Upstream-Commit: d2e570cc0f97b936902a5b1b86b73c0f5998b475

replay/replay-snapshot.c

@@ -0,0 +1,99 @@
+/*
+ * replay-snapshot.c
+ *
+ * Copyright (c) 2010-2016 Institute for System Programming
+ *                         of the Russian Academy of Sciences.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "system/replay.h"
+#include "replay-internal.h"
+#include "monitor/monitor.h"
+#include "qobject/qstring.h"
+#include "qemu/error-report.h"
+#include "migration/vmstate.h"
+#include "migration/snapshot.h"
+
+static int replay_pre_save(void *opaque)
+{
+    ReplayState *state = opaque;
+    state->file_offset = ftell(replay_file);
+
+    return 0;
+}
+
+static int replay_post_load(void *opaque, int version_id)
+{
+    ReplayState *state = opaque;
+    if (replay_mode == REPLAY_MODE_PLAY) {
+        fseek(replay_file, state->file_offset, SEEK_SET);
+        /* If this was a vmstate, saved in recording mode,
+           we need to initialize replay data fields. */
+        replay_fetch_data_kind();
+    } else if (replay_mode == REPLAY_MODE_RECORD) {
+        /* This is only useful for loading the initial state.
+           Therefore reset all the counters. */
+        state->instruction_count = 0;
+        state->block_request_id = 0;
+    }
+
+    return 0;
+}
+
+static const VMStateDescription vmstate_replay = {
+    .name = "replay",
+    .version_id = 3,
+    .minimum_version_id = 3,
+    .pre_save = replay_pre_save,
+    .post_load = replay_post_load,
+    .fields = (const VMStateField[]) {
+        VMSTATE_INT64_ARRAY(cached_clock, ReplayState, REPLAY_CLOCK_COUNT),
+        VMSTATE_UINT64(current_icount, ReplayState),
+        VMSTATE_INT32(instruction_count, ReplayState),
+        VMSTATE_UINT32(current_event, ReplayState),
+        VMSTATE_UINT32(data_kind, ReplayState),
+        VMSTATE_BOOL(has_unread_data, ReplayState),
+        VMSTATE_UINT64(file_offset, ReplayState),
+        VMSTATE_UINT64(block_request_id, ReplayState),
+        VMSTATE_UINT64(read_event_id, ReplayState),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+void replay_vmstate_register(void)
+{
+    vmstate_register(NULL, 0, &vmstate_replay, &replay_state);
+}
+
+void replay_vmstate_init(void)
+{
+    Error *err = NULL;
+
+    if (replay_snapshot) {
+        if (replay_mode == REPLAY_MODE_RECORD) {
+            if (!save_snapshot(replay_snapshot,
+                               true, NULL, false, NULL, &err)) {
+                error_report_err(err);
+                error_report("Could not create snapshot for icount record");
+                exit(1);
+            }
+        } else if (replay_mode == REPLAY_MODE_PLAY) {
+            if (!load_snapshot(replay_snapshot, NULL, false, NULL, &err)) {
+                error_report_err(err);
+                error_report("Could not load snapshot for icount replay");
+                exit(1);
+            }
+        }
+    }
+}
+
+bool replay_can_snapshot(void)
+{
+    return replay_mode == REPLAY_MODE_NONE
+        || !replay_has_events();
+}