Re: [RFC PATCH] tests/functional/s390x: Add reverse debugging test for s390x

[Ilya Leoshkevich <iii@linux.ibm.com>]

On Fri, 2025-11-28 at 14:39 +0100, Thomas Huth wrote:
> From: Thomas Huth <thuth@redhat.com>
> 
> We just have to make sure that we can set the endianness to big
> endian,
> then we can also run this test on s390x.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  Marked as RFC since it depends on the fix for this bug (so it cannot
>  be merged yet):
>  
> https://lore.kernel.org/qemu-devel/a0accce9-6042-4a7b-a7c7-218212818891@redhat.com
> /
> 
>  tests/functional/reverse_debugging.py        |  4 +++-
>  tests/functional/s390x/meson.build           |  1 +
>  tests/functional/s390x/test_reverse_debug.py | 21
> ++++++++++++++++++++
>  3 files changed, 25 insertions(+), 1 deletion(-)
>  create mode 100755 tests/functional/s390x/test_reverse_debug.py

Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>


I have a simple fix which helps with your original report, but not
with this test. I'm still investigating.

--- a/target/s390x/machine.c
+++ b/target/s390x/machine.c
@@ -52,6 +52,14 @@ static int cpu_pre_save(void *opaque)
         kvm_s390_vcpu_interrupt_pre_save(cpu);
     }
 
+    if (tcg_enabled()) {
+        /*
+         * Ensure symmetry with cpu_post_load() with respect to
+         * CHECKPOINT_CLOCK_VIRTUAL.
+         */
+        tcg_s390_tod_updated(CPU(cpu), RUN_ON_CPU_NULL);
+    }
+
     return 0;
 }