replay: introduce icount event

This patch adds icount event to the replay subsystem. This event corresponds
to execution of several instructions and used to synchronize input events
in the replay phase.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162354.8676.31351.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/replay/replay-internal.c b/replay/replay-internal.c
index efae672dfa..35cff44a36 100644
--- a/replay/replay-internal.c
+++ b/replay/replay-internal.c
@@ -10,6 +10,7 @@
  */
 
 #include "qemu-common.h"
+#include "sysemu/replay.h"
 #include "replay-internal.h"
 #include "qemu/error-report.h"
 #include "sysemu/sysemu.h"
@@ -36,6 +37,7 @@ void replay_put_byte(uint8_t byte)
 
 void replay_put_event(uint8_t event)
 {
+    assert(event < EVENT_COUNT);
     replay_put_byte(event);
 }
 
@@ -149,8 +151,15 @@ void replay_fetch_data_kind(void)
     if (replay_file) {
         if (!replay_has_unread_data) {
             replay_data_kind = replay_get_byte();
+            if (replay_data_kind == EVENT_INSTRUCTION) {
+                replay_state.instructions_count = replay_get_dword();
+            }
             replay_check_error();
             replay_has_unread_data = 1;
+            if (replay_data_kind >= EVENT_COUNT) {
+                error_report("Replay: unknown event kind %d", replay_data_kind);
+                exit(1);
+            }
         }
     }
 }
@@ -180,3 +189,18 @@ void replay_mutex_unlock(void)
 {
     qemu_mutex_unlock(&lock);
 }
+
+/*! Saves cached instructions. */
+void replay_save_instructions(void)
+{
+    if (replay_file && replay_mode == REPLAY_MODE_RECORD) {
+        replay_mutex_lock();
+        int diff = (int)(replay_get_current_step() - replay_state.current_step);
+        if (diff > 0) {
+            replay_put_event(EVENT_INSTRUCTION);
+            replay_put_dword(diff);
+            replay_state.current_step += diff;
+        }
+        replay_mutex_unlock();
+    }
+}