replay: recording and replaying clock ticks

Clock ticks are considered as the sources of non-deterministic data for
virtual machine. This patch implements saving the clock values when they
are acquired (virtual, host clock).
When replaying the execution corresponding values are read from log and
transfered to the module, which wants to read the values.
Such a design required the clock polling to be synchronized. Sometimes
it is not true - e.g. when timeouts for timer lists are checked. In this case
we use a cached value of the clock, passing it to the client code.

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162427.8676.36558.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>

1 files changed, 13 insertions, 0 deletions

diff --git a/stubs/replay.c b/stubs/replay.c
index 12c1a7557d..f0d95b05f1 100644
--- a/stubs/replay.c
+++ b/stubs/replay.c
@@ -1,3 +1,16 @@
 #include "sysemu/replay.h"
+#include <stdlib.h>
 
 ReplayMode replay_mode;
+
+int64_t replay_save_clock(unsigned int kind, int64_t clock)
+{
+    abort();
+    return 0;
+}
+
+int64_t replay_read_clock(unsigned int kind)
+{
+    abort();
+    return 0;
+}