[Qemu-devel] [PATCH] replay: check icount in cpu exec loop

[Qemu-devel] [PATCH] replay: check icount in cpu exec loop

[Pavel Dovgalyuk]

This patch adds check to break cpu loop when icount expires without
setting the TB_EXIT_ICOUNT_EXPIRED flag. It happens when there is no
available translated blocks and all instructions were executed.
In icount replay mode unnecessary tb_find will be called (which may
cause an exception) and execution will be non-deterministic.

This patch should be applied over Paolo's series:
https://www.mail-archive.com/qemu-devel@nongnu.org/msg426058.html

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
---
 cpu-exec.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/cpu-exec.c b/cpu-exec.c
index 3838eb8..5cef8bc 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -519,7 +519,8 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
     }
 
     /* Finally, check if we need to exit to the main loop.  */
-    if (unlikely(atomic_read(&cpu->exit_request) || replay_has_interrupt())) {
+    if (unlikely(atomic_read(&cpu->exit_request)
+        || (use_icount && cpu->icount_decr.u16.low + cpu->icount_extra == 0))) {
         atomic_set(&cpu->exit_request, 0);
         cpu->exception_index = EXCP_INTERRUPT;
         return true;
-- 
2.8.1