Re: [RFC PATCH 5/5] tests: stop skipping migration test on s390x/ppc64

[Thomas Huth <thuth@redhat.com>]

On 28/06/2022 12.54, Daniel P. Berrangé wrote:
> There have been checks put into the migration test which skip it in a
> few scenarios
> 
>   * ppc64 TCG
>   * ppc64 KVM with kvm-pr
>   * s390x TCG
> 
> In the original commits there are references to unexplained hangs in
> the test. There is no record of details of where it was hanging, but
> it is suspected that these were all a result of the max downtime limit
> being set at too low a value to guarantee convergance.
> 
> Since a previous commit bumped the value from 1 second to 30 seconds,
> it is believed that hangs due to non-convergance should be eliminated
> and thus worth trying to remove the skipped scenarios.
> 
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>   tests/qtest/migration-test.c | 21 ---------------------
>   1 file changed, 21 deletions(-)
> 
> diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
> index 9e64125f02..500169f687 100644
> --- a/tests/qtest/migration-test.c
> +++ b/tests/qtest/migration-test.c
> @@ -2085,7 +2085,6 @@ static bool kvm_dirty_ring_supported(void)
>   int main(int argc, char **argv)
>   {
>       char template[] = "/tmp/migration-test-XXXXXX";
> -    const bool has_kvm = qtest_has_accel("kvm");
>       int ret;
>   
>       g_test_init(&argc, &argv, NULL);
> @@ -2094,26 +2093,6 @@ int main(int argc, char **argv)
>           return g_test_run();
>       }
>   
> -    /*
> -     * 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(qtest_get_arch(), "ppc64") &&
> -        (!has_kvm || access("/sys/module/kvm_hv", F_OK))) {
> -        g_test_message("Skipping test: kvm_hv not available");
> -        return g_test_run();
> -    }
> -
> -    /*
> -     * Similar to ppc64, s390x seems to be touchy with TCG, so disable it
> -     * there until the problems are resolved
> -     */
> -    if (g_str_equal(qtest_get_arch(), "s390x") && !has_kvm) {
> -        g_test_message("Skipping test: s390x host with KVM is required");
> -        return g_test_run();
> -    }

I'm in favor of giving this now a try ... we still can revert the patch if 
it does not work out.

Reviewed-by: Thomas Huth <thuth@redhat.com>