From: Pavel Dovgalyuk <pavel.dovga...@gmail.com>
Commit 9458a9a1df1a4c719e24512394d548c1fc7abd22 added synchronization
of vCPU and migration operations through calling run_on_cpu operation.
However, in replay mode this synchronization is unneeded, because
I/O and vCPU threads are already synchronized.
This patch disables such synchronization for record/replay mode.
Signed-off-by: Pavel Dovgalyuk <pavel.dovga...@ispras.ru>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
Signed-off-by: Pavel Dovgalyuk <pavel.dovga...@gmail.com>
---
exec.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/exec.c b/exec.c
index 8a0a661..1d6e4d8 100644
--- a/exec.c
+++ b/exec.c
@@ -2959,8 +2959,17 @@ static void tcg_log_global_after_sync(MemoryListener
*listener)
* by pushing the migration thread's memory read after the vCPU thread has
* written the memory.
*/
- cpuas = container_of(listener, CPUAddressSpace, tcg_as_listener);
- run_on_cpu(cpuas->cpu, do_nothing, RUN_ON_CPU_NULL);
+ if (replay_mode == REPLAY_MODE_NONE) {
+ /*
+ * VGA can make calls to this function while updating the screen.
+ * In record/replay mode this causes a deadlock, because
+ * run_on_cpu waits for rr mutex. Therefore no races are possible
+ * in this case and no need for making run_on_cpu when
+ * record/replay is not enabled.
+ */
+ cpuas = container_of(listener, CPUAddressSpace, tcg_as_listener);
+ run_on_cpu(cpuas->cpu, do_nothing, RUN_ON_CPU_NULL);
+ }
}
static void tcg_commit(MemoryListener *listener)
--
1.8.3.1
