ppc64 with TCG seems to no longer be failing this test, perhaps since
commit 03bfc2188f061 ("physmem: Fix migration dirty bitmap coherency
with TCG memory access") which is not ppc specific but was seen to hit
ppc64 quite easily.

Let's enable it again.

The s390x problem has been identified so mention it while we are
adjusting the comment.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 tests/qtest/migration-test.c | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index 48f59822f4..ef9ddef1c8 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -3454,19 +3454,9 @@ int main(int argc, char **argv)
 #endif
 
     /*
-     * On ppc64, the test only works with kvm-hv, but not with kvm-pr and TCG
-     * is touchy due to race conditions on dirty bits (especially on PPC for
-     * some reason)
-     */
-    if (g_str_equal(arch, "ppc64") &&
-        (!has_kvm || access("/sys/module/kvm_hv", F_OK))) {
-        g_test_message("Skipping tests: kvm_hv not available");
-        goto test_add_done;
-    }
-
-    /*
-     * Similar to ppc64, s390x seems to be touchy with TCG, so disable it
-     * there until the problems are resolved
+     * On s390x with TCG, migration is observed to hang due to the 'pending'
+     * state of the flic interrupt controller not being migrated or
+     * reconstructed post-migration. Disable it until the problem is resolved.
      */
     if (g_str_equal(arch, "s390x") && !has_kvm) {
         g_test_message("Skipping tests: s390x host with KVM is required");
-- 
2.43.0

On Thu, 30 May 2024 at 13:17, Nicholas Piggin <npiggin@gmail.com> wrote:
> diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
>      /*
> -     * On ppc64, the test only works with kvm-hv, but not with kvm-pr and TCG
> -     * is touchy due to race conditions on dirty bits (especially on PPC for
> -     * some reason)
> -     */
> -    if (g_str_equal(arch, "ppc64") &&
> -        (!has_kvm || access("/sys/module/kvm_hv", F_OK))) {
> -        g_test_message("Skipping tests: kvm_hv not available");
> -        goto test_add_done;
> -    }
> -
> -    /*
> -     * Similar to ppc64, s390x seems to be touchy with TCG, so disable it
> -     * there until the problems are resolved
> +     * On s390x with TCG, migration is observed to hang due to the 'pending'
> +     * state of the flic interrupt controller not being migrated or
> +     * reconstructed post-migration. Disable it until the problem is resolved.
>       */
>      if (g_str_equal(arch, "s390x") && !has_kvm) {
>          g_test_message("Skipping tests: s390x host with KVM is required");
> --
> 2.43.0

Reviewed-by: Prasad Pandit <pjp@fedoraproject.org>

Thank you.
---
  - Prasad