Re: tpm-tis-device-swtpm-test timeout

[Stefan Berger <stefanb@linux.ibm.com>]

On 10/15/24 7:35 PM, Stefan Berger wrote:
> 
> 
> On 10/15/24 6:02 PM, Fabiano Rosas wrote:
>> Stefan Berger <stefanb@linux.ibm.com> writes:
>>

>>>
>>
>> Yes, I've been using that method to reproduce live migration race
>> conditions as well. It's quite effective.
>>
>> If you don't think you'll be able to find the root cause due to the
>> unreproducibility on your side, maybe we could at least add an assert
>> that bcount is not larger than rsp_size. I think that would at least
>> give an explicit error instead of a buffer overflow.
>>
>> I can also try to dig deeper into this when I get some time. At the
>> moment I know nothing about the tpm device emulation.
>>
> 
> The loop has run 3000 times by itself so that part is stable. However, 
> it seems there is some other test case that the loop cannot run in 
> parallel with. So, yes there is 'something'. ... ... Just having all 
> CPUs in a system busy requires waiting for migration to be complete on 
> the dst_qemu side as well. Can you try it with this patch:
> 
> diff --git a/tests/qtest/tpm-tests.c b/tests/qtest/tpm-tests.c
> index fb94496bbd..b52cd44841 100644
> --- a/tests/qtest/tpm-tests.c
> +++ b/tests/qtest/tpm-tests.c
> @@ -115,6 +115,7 @@ void tpm_test_swtpm_migration_test(const char 
> *src_tpm_path,
> 
>       tpm_util_migrate(src_qemu, uri);
>       tpm_util_wait_for_migration_complete(src_qemu);
> +    tpm_util_wait_for_migration_complete(dst_qemu);
> 
>       tpm_util_pcrread(dst_qemu, tx, tpm_pcrread_resp,
>                        sizeof(tpm_pcrread_resp));
> 

Only waiting on the destination side is also possible:

diff --git a/tests/qtest/tpm-tests.c b/tests/qtest/tpm-tests.c
index fb94496bbd..197714f8d9 100644
--- a/tests/qtest/tpm-tests.c
+++ b/tests/qtest/tpm-tests.c
@@ -114,7 +114,7 @@ void tpm_test_swtpm_migration_test(const char 
*src_tpm_path,
                       sizeof(tpm_pcrread_resp));

      tpm_util_migrate(src_qemu, uri);
-    tpm_util_wait_for_migration_complete(src_qemu);
+    tpm_util_wait_for_migration_complete(dst_qemu);

      tpm_util_pcrread(dst_qemu, tx, tpm_pcrread_resp,
                       sizeof(tpm_pcrread_resp));