[Qemu-devel] [RFC PATCH v6 17/32] cpu: replay instructions sequence

[Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>]

This patch adds calls to replay functions into the icount setup block.
In record mode number of executed instructions is written to the log.
In replay mode number of istructions to execute is taken from the replay log.

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
---
 cpu-exec.c      |    1 +
 cpus.c          |   28 ++++++++++++++++++----------
 replay/replay.c |   21 +++++++++++++++++++++
 replay/replay.h |    4 ++++
 4 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/cpu-exec.c b/cpu-exec.c
index 38c9d60..bd80a0e 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -530,6 +530,7 @@ int cpu_exec(CPUArchState *env)
                             }
                             cpu->exception_index = EXCP_INTERRUPT;
                             next_tb = 0;
+                            qemu_notify_event();
                             cpu_loop_exit(cpu);
                         }
                         break;
diff --git a/cpus.c b/cpus.c
index 6602acc..af863e6 100644
--- a/cpus.c
+++ b/cpus.c
@@ -41,6 +41,7 @@
 #include "qemu/seqlock.h"
 #include "qapi-event.h"
 #include "hw/nmi.h"
+#include "replay/replay.h"
 
 #ifndef _WIN32
 #include "qemu/compatfd.h"
@@ -1346,18 +1347,22 @@ static int tcg_cpu_exec(CPUArchState *env)
                                     + cpu->icount_extra);
         cpu->icount_decr.u16.low = 0;
         cpu->icount_extra = 0;
-        deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL);
+        if (replay_mode != REPLAY_MODE_PLAY) {
+            deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL);
 
-        /* Maintain prior (possibly buggy) behaviour where if no deadline
-         * was set (as there is no QEMU_CLOCK_VIRTUAL timer) or it is more than
-         * INT32_MAX nanoseconds ahead, we still use INT32_MAX
-         * nanoseconds.
-         */
-        if ((deadline < 0) || (deadline > INT32_MAX)) {
-            deadline = INT32_MAX;
-        }
+            /* Maintain prior (possibly buggy) behaviour where if no deadline
+             * was set (as there is no QEMU_CLOCK_VIRTUAL timer) or it is more than
+             * INT32_MAX nanoseconds ahead, we still use INT32_MAX
+             * nanoseconds.
+             */
+            if ((deadline < 0) || (deadline > INT32_MAX)) {
+                deadline = INT32_MAX;
+            }
 
-        count = qemu_icount_round(deadline);
+            count = qemu_icount_round(deadline);
+        } else {
+            count = replay_get_instructions();
+        }
         timers_state.qemu_icount += count;
         decr = (count > 0xffff) ? 0xffff : count;
         count -= decr;
@@ -1375,6 +1380,9 @@ static int tcg_cpu_exec(CPUArchState *env)
                         + cpu->icount_extra);
         cpu->icount_decr.u32 = 0;
         cpu->icount_extra = 0;
+        if (replay_mode == REPLAY_MODE_PLAY) {
+            replay_exec_instructions();
+        }
     }
     return ret;
 }
diff --git a/replay/replay.c b/replay/replay.c
index 93d3d7e..18a4a29 100755
--- a/replay/replay.c
+++ b/replay/replay.c
@@ -68,3 +68,24 @@ uint64_t replay_get_current_step(void)
 {
     return cpu_get_icount_raw();
 }
+
+int replay_get_instructions(void)
+{
+    if (skip_async_events(EVENT_INSTRUCTION)) {
+        return replay_state.instructions_count;
+    }
+    return 0;
+}
+
+void replay_exec_instructions(void)
+{
+    if (replay_state.instructions_count > 0) {
+        int count = (int)(replay_get_current_step()
+                          - replay_state.current_step);
+        replay_state.instructions_count -= count;
+        replay_state.current_step += count;
+        if (replay_state.instructions_count == 0 && count != 0) {
+            replay_has_unread_data = 0;
+        }
+    }
+}
diff --git a/replay/replay.h b/replay/replay.h
index e40daf5..382dc7b 100755
--- a/replay/replay.h
+++ b/replay/replay.h
@@ -26,5 +26,9 @@ ReplaySubmode replay_get_play_submode(void);
 
 /*! Returns number of executed instructions. */
 uint64_t replay_get_current_step(void);
+/*! Returns number of instructions to execute in replay mode. */
+int replay_get_instructions(void);
+/*! Updates instructions counter in replay mode. */
+void replay_exec_instructions(void);
 
 #endif