[Qemu-devel] [RFC 2/3] icount: sync vm_clock on the next event.

[fred.konrad@greensocs.com]

From: KONRAD Frederic <fred.konrad@greensocs.com>

We don't want vm_clock to be synchronized with rt_clock as it is
not deterministic for replay.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
---
 cpus.c      | 11 +++++++++--
 main-loop.c |  5 +++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/cpus.c b/cpus.c
index 46504d0..fb83153 100644
--- a/cpus.c
+++ b/cpus.c
@@ -64,6 +64,8 @@
 
 static CPUArchState *next_cpu;
 
+void icount_warp_rt(void *opaque);
+
 static bool cpu_thread_is_idle(CPUState *cpu)
 {
     if (cpu->stop || cpu->queued_work_first) {
@@ -277,7 +279,7 @@ static int64_t qemu_icount_round(int64_t count)
     return (count + (1 << icount_time_shift) - 1) >> icount_time_shift;
 }
 
-static void icount_warp_rt(void *opaque)
+void icount_warp_rt(void *opaque)
 {
     if (vm_clock_warp_start == -1) {
         return;
@@ -286,8 +288,13 @@ static void icount_warp_rt(void *opaque)
     if (runstate_is_running()) {
         int64_t clock = qemu_get_clock_ns(rt_clock);
         int64_t warp_delta = clock - vm_clock_warp_start;
+        int64_t next_vm_deadline = qemu_clock_deadline(vm_clock);
         if (use_icount == 1) {
-            qemu_icount_bias += warp_delta;
+            if (next_vm_deadline > 0) {
+                qemu_icount_bias += next_vm_deadline;
+            } else {
+                qemu_notify_event();
+            }
         } else {
             /*
              * In adaptive mode, do not let the vm_clock run too
diff --git a/main-loop.c b/main-loop.c
index a44fff6..16c9b85 100644
--- a/main-loop.c
+++ b/main-loop.c
@@ -33,6 +33,8 @@
 
 #include "qemu/compatfd.h"
 
+void icount_warp_rt(void *opaque);
+
 /* If we have signalfd, we mask out the signals we want to handle and then
  * use signalfd to listen for them.  We rely on whatever the current signal
  * handler is to dispatch the signals when we receive them.
@@ -470,6 +472,9 @@ int main_loop_wait(int nonblocking)
 
     qemu_run_all_timers();
 
+    if (use_icount == 1) {
+        icount_warp_rt(NULL);
+    }
     return ret;
 }
 
-- 
1.8.1.4