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>

diff --git a/include/sysemu/replay.h b/include/sysemu/replay.h
index d6b73c33046adb088fb7be5a8e98d096472f3849..a03c7485d4a2935507f35e796d23f173137261d6 100644 (file)
--- a/include/sysemu/replay.h
+++ b/include/sysemu/replay.h
@@ -12,8 +12,15 @@
  *
  */
 
+#include <stdbool.h>
+#include <stdint.h>
 #include "qapi-types.h"
 
 extern ReplayMode replay_mode;
 
+/* Processing the instructions */
+
+/*! Returns number of executed instructions. */
+uint64_t replay_get_current_step(void);
+
 #endif

diff --git a/replay/replay-internal.c b/replay/replay-internal.c
index efae672dfa57d57c89e21ecb715b3fa73470ecb7..35cff44a36fc391b095bc546db1d2d3dcb146728 100644 (file)
--- 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();
+    }
+}

diff --git a/replay/replay-internal.h b/replay/replay-internal.h
index 8a0de0d8d8b4e19d50e2a96be88253063fceacf4..ff4fabc3261ae353ca556ea566e8822e6cc14c42 100644 (file)
--- a/replay/replay-internal.h
+++ b/replay/replay-internal.h
@@ -14,6 +14,20 @@
 
 #include <stdio.h>
 
+enum ReplayEvents {
+    /* for instruction event */
+    EVENT_INSTRUCTION,
+    EVENT_COUNT
+};
+
+typedef struct ReplayState {
+    /*! Current step - number of processed instructions and timer events. */
+    uint64_t current_step;
+    /*! Number of instructions to be executed before other events happen. */
+    int instructions_count;
+} ReplayState;
+extern ReplayState replay_state;
+
 extern unsigned int replay_data_kind;
 
 /* File for replay writing */
@@ -50,4 +64,11 @@ void replay_finish_event(void);
     replay_data_kind variable. */
 void replay_fetch_data_kind(void);
 
+/*! Saves queued events (like instructions and sound). */
+void replay_save_instructions(void);
+
+/*! Skips async events until some sync event will be found.
+    \return true, if event was found */
+bool replay_next_event_is(int event);
+
 #endif

diff --git a/replay/replay.c b/replay/replay.c
index a0ef04f822a1412bdf3369611b3b9293e79bcc0a..62e8abaadf5366d8f389ae2fb60659e37e254bf6 100644 (file)
--- a/replay/replay.c
+++ b/replay/replay.c
@@ -9,6 +9,39 @@
  *
  */
 
+#include "qemu-common.h"
 #include "sysemu/replay.h"
+#include "replay-internal.h"
+#include "qemu/timer.h"
 
 ReplayMode replay_mode = REPLAY_MODE_NONE;
+
+ReplayState replay_state;
+
+bool replay_next_event_is(int event)
+{
+    bool res = false;
+
+    /* nothing to skip - not all instructions used */
+    if (replay_state.instructions_count != 0) {
+        assert(replay_data_kind == EVENT_INSTRUCTION);
+        return event == EVENT_INSTRUCTION;
+    }
+
+    while (true) {
+        if (event == replay_data_kind) {
+            res = true;
+        }
+        switch (replay_data_kind) {
+        default:
+            /* clock, time_t, checkpoint and other events */
+            return res;
+        }
+    }
+    return res;
+}
+
+uint64_t replay_get_current_step(void)
+{
+    return cpu_get_icount_raw();
+}