migration test fails for aarch64 target (was: Re: [PULL 08/30] tests: Add dirty page rate limit test)

[Thomas Huth]

On 20/07/2022 13.19, Dr. David Alan Gilbert (git) wrote:
> From: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
>
> Add dirty page rate limit test if kernel support dirty ring,
>
> The following qmp commands are covered by this test case:
> "calc-dirty-rate", "query-dirty-rate", "set-vcpu-dirty-limit",
> "cancel-vcpu-dirty-limit" and "query-vcpu-dirty-limit".
>
> Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
> Acked-by: Peter Xu <peterx@redhat.com>
> Message-Id: 
> <eed5b847a6ef0a9c02a36383dbdd7db367dd1e7e.1656177590.git.huangy81@chinatelecom.cn>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
>   tests/qtest/migration-helpers.c |  22 +++
>   tests/qtest/migration-helpers.h |   2 +
>   tests/qtest/migration-test.c    | 256 ++++++++++++++++++++++++++++++++
>   3 files changed, 280 insertions(+)
[...]
> +static QTestState *dirtylimit_start_vm(void)
> +{
> +    QTestState *vm = NULL;
> +    g_autofree gchar *cmd = NULL;
> +    const char *arch = qtest_get_arch();
> +    g_autofree char *bootpath = NULL;
> +
> +    assert((strcmp(arch, "x86_64") == 0));

 Hi!

This assert triggers on my x86 laptop when I run "make check" there. More 
precisely, it triggers when qemu-system-aarch64 is getting tested:

$ QTEST_QEMU_BINARY=./qemu-system-aarch64 tests/qtest/migration-test
/aarch64/migration/bad_dest: OK
/aarch64/migration/fd_proto: OK
/aarch64/migration/validate_uuid: OK
/aarch64/migration/validate_uuid_error: OK
/aarch64/migration/validate_uuid_src_not_set: OK
/aarch64/migration/validate_uuid_dst_not_set: OK
/aarch64/migration/auto_converge: OK
/aarch64/migration/dirty_ring: OK
/aarch64/migration/vcpu_dirty_limit: migration-test: 
../../devel/qemu/tests/qtest/migration-test.c:2304: dirtylimit_start_vm: 
Assertion `(strcmp(arch, "x86_64") == 0)' failed.
Aborted (core dumped)

>   static bool kvm_dirty_ring_supported(void)
>   {
>   #if defined(__linux__) && defined(HOST_X86_64)
> @@ -2204,6 +2458,8 @@ int main(int argc, char **argv)
>       if (kvm_dirty_ring_supported()) {
>           qtest_add_func("/migration/dirty_ring",
>                          test_precopy_unix_dirty_ring);
> +        qtest_add_func("/migration/vcpu_dirty_limit",
> +                       test_vcpu_dirty_limit);
>       }

kvm_dirty_ring_supported() returns "true" if the KVM of the *host* is x86 
and has the dirty ring support, but it does *not* check the target 
architecture that is currently tested, so you also get here "true" for 
qemu-system-aarch64 being tested on a x86 host... Thus I guess 
kvm_dirty_ring_supported() needs also a check for the right target architecture?

 Thomas