[PATCH 2/7] target/ppc: Fix timebase reset with record-replay

Nicholas Piggin posted 7 patches 2 years, 6 months ago
Maintainers: Daniel Henrique Barboza <danielhb413@gmail.com>, "Cédric Le Goater" <clg@kaod.org>, David Gibson <david@gibson.dropbear.id.au>, Greg Kurz <groug@kaod.org>, Nicholas Piggin <npiggin@gmail.com>, Harsh Prateek Bora <harshpb@linux.ibm.com>, Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>, Paolo Bonzini <pbonzini@redhat.com>, Cleber Rosa <crosa@redhat.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Wainer dos Santos Moschetta <wainersm@redhat.com>, Beraldo Leal <bleal@redhat.com>
[PATCH 2/7] target/ppc: Fix timebase reset with record-replay
Posted by Nicholas Piggin 2 years, 6 months ago
Timebase save uses a random number for a legacy vmstate field, which
makes rr snapshot loading unbalanced. The easiest way to deal with this
is just to skip the rng if record-replay is active.

Reviewed-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 hw/ppc/ppc.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c
index cd1993e9c1..2476c4c4d3 100644
--- a/hw/ppc/ppc.c
+++ b/hw/ppc/ppc.c
@@ -32,6 +32,7 @@
 #include "qemu/main-loop.h"
 #include "qemu/error-report.h"
 #include "sysemu/kvm.h"
+#include "sysemu/replay.h"
 #include "sysemu/runstate.h"
 #include "kvm_ppc.h"
 #include "migration/vmstate.h"
@@ -937,8 +938,14 @@ static void timebase_save(PPCTimebase *tb)
         return;
     }
 
-    /* not used anymore, we keep it for compatibility */
-    tb->time_of_the_day_ns = qemu_clock_get_ns(QEMU_CLOCK_HOST);
+    if (replay_mode == REPLAY_MODE_NONE) {
+        /* not used anymore, we keep it for compatibility */
+        tb->time_of_the_day_ns = qemu_clock_get_ns(QEMU_CLOCK_HOST);
+    } else {
+        /* simpler for record-replay to avoid this event, compat not needed */
+        tb->time_of_the_day_ns = 0;
+    }
+
     /*
      * tb_offset is only expected to be changed by QEMU so
      * there is no need to update it from KVM here
-- 
2.40.1