replay: fix icount request when replaying clock access

Record/replay provides REPLAY_CLOCK_LOCKED macro to access
the clock when vm_clock_seqlock is locked. This macro is
needed because replay internals operate icount. In locked case
replay use icount_get_raw_locked for icount request, which prevents
excess locking which leads to deadlock. But previously only
record code used *_locked function and replay did not.
Therefore sometimes clock access lead to deadlocks.
This patch fixes clock access for replay too and uses *_locked
icount access function.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Message-Id: <161347990483.1313189.8371838968343494161.stgit@pasha-ThinkPad-X280>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 25 insertions, 4 deletions

diff --git a/replay/replay-internal.c b/replay/replay-internal.c
index 2e8a3e9..77d0c82 100644
--- a/replay/replay-internal.c
+++ b/replay/replay-internal.c
@@ -247,10 +247,31 @@ void replay_advance_current_icount(uint64_t current_icount)
     /* Time can only go forward */
     assert(diff >= 0);
 
-    if (diff > 0) {
-        replay_put_event(EVENT_INSTRUCTION);
-        replay_put_dword(diff);
-        replay_state.current_icount += diff;
+    if (replay_mode == REPLAY_MODE_RECORD) {
+        if (diff > 0) {
+            replay_put_event(EVENT_INSTRUCTION);
+            replay_put_dword(diff);
+            replay_state.current_icount += diff;
+        }
+    } else if (replay_mode == REPLAY_MODE_PLAY) {
+        if (diff > 0) {
+            replay_state.instruction_count -= diff;
+            replay_state.current_icount += diff;
+            if (replay_state.instruction_count == 0) {
+                assert(replay_state.data_kind == EVENT_INSTRUCTION);
+                replay_finish_event();
+                /* Wake up iothread. This is required because
+                    timers will not expire until clock counters
+                    will be read from the log. */
+                qemu_notify_event();
+            }
+        }
+        /* Execution reached the break step */
+        if (replay_break_icount == replay_state.current_icount) {
+            /* Cannot make callback directly from the vCPU thread */
+            timer_mod_ns(replay_break_timer,
+                qemu_clock_get_ns(QEMU_CLOCK_REALTIME));
+        }
     }
 }