With Cosmic s390x KVM, 6 failures reported in our source tree and in the upstream source tree:
[ RUN      ] TRACE_syscall.ptrace_syscall_dropped
TRACE_syscall.ptrace_syscall_dropped: Test failed at step #127
[     FAIL ] TRACE_syscall.ptrace_syscall_dropped
[ RUN      ] TRACE_syscall.syscall_dropped
TRACE_syscall.syscall_dropped: Test failed at step #2
[     FAIL ] TRACE_syscall.syscall_dropped
[ RUN      ] TRACE_syscall.skip_after_RET_TRACE
seccomp_bpf.c:1884:TRACE_syscall.skip_after_RET_TRACE:Expected -1 (18446744073709551615) == syscall(20) (728)
seccomp_bpf.c:1885:TRACE_syscall.skip_after_RET_TRACE:Expected 1 (1) == (*__errno_location ()) (0)
TRACE_syscall.skip_after_RET_TRACE: Test failed at step #12
[     FAIL ] TRACE_syscall.skip_after_RET_TRACE
[ RUN      ] TRACE_syscall.kill_after_RET_TRACE
TRACE_syscall.kill_after_RET_TRACE: Test exited normally instead of by signal (code: 0)
[     FAIL ] TRACE_syscall.kill_after_RET_TRACE
[ RUN      ] TRACE_syscall.skip_after_ptrace
seccomp_bpf.c:1946:TRACE_syscall.skip_after_ptrace:Expected -1 (18446744073709551615) == syscall(20) (728)
seccomp_bpf.c:1947:TRACE_syscall.skip_after_ptrace:Expected 1 (1) == (*__errno_location ()) (0)
TRACE_syscall.skip_after_ptrace: Test failed at step #15
[     FAIL ] TRACE_syscall.skip_after_ptrace
[ RUN      ] TRACE_syscall.kill_after_ptrace
TRACE_syscall.kill_after_ptrace: Test exited normally instead of by signal (code: 0)
[     FAIL ] TRACE_syscall.kill_after_ptrace

With Xenail s390x KVM, the test suite is outdated and it will pass with 54 tests there. With the upstream source tree, there will be 8 failures:
[ RUN      ] global.KILL_process
seccomp_bpf.c:727:global.KILL_process:Expected 0 (0) != (((signed char) ((((__extension__ (((union { __typeof(status) __in; int __i; }) { .__in = (status) }).__i))) & 0x7f) + 1) >> 1) > 0) (0)
global.KILL_process: Test terminated by assertion
[     FAIL ] global.KILL_process
[ RUN      ] TRACE_syscall.ptrace_syscall_dropped
TRACE_syscall.ptrace_syscall_dropped: Test failed at step #223
[     FAIL ] TRACE_syscall.ptrace_syscall_dropped
[ RUN      ] TRACE_syscall.syscall_dropped
TRACE_syscall.syscall_dropped: Test failed at step #2
[     FAIL ] TRACE_syscall.syscall_dropped
[ RUN      ] TRACE_syscall.skip_after_RET_TRACE
seccomp_bpf.c:1884:TRACE_syscall.skip_after_RET_TRACE:Expected -1 (18446744073709551615) == syscall(20) (5486)
seccomp_bpf.c:1885:TRACE_syscall.skip_after_RET_TRACE:Expected 1 (1) == (*__errno_location ()) (0)
TRACE_syscall.skip_after_RET_TRACE: Test failed at step #12
[     FAIL ] TRACE_syscall.skip_after_RET_TRACE
[ RUN      ] TRACE_syscall.kill_after_RET_TRACE
TRACE_syscall.kill_after_RET_TRACE: Test exited normally instead of by signal (code: 0)
[     FAIL ] TRACE_syscall.kill_after_RET_TRACE
[ RUN      ] TRACE_syscall.skip_after_ptrace
seccomp_bpf.c:1946:TRACE_syscall.skip_after_ptrace:Expected -1 (18446744073709551615) == syscall(20) (5486)
seccomp_bpf.c:1947:TRACE_syscall.skip_after_ptrace:Expected 1 (1) == (*__errno_location ()) (0)
TRACE_syscall.skip_after_ptrace: Test failed at step #15
[     FAIL ] TRACE_syscall.skip_after_ptrace
[ RUN      ] TRACE_syscall.kill_after_ptrace
TRACE_syscall.kill_after_ptrace: Test exited normally instead of by signal (code: 0)
[     FAIL ] TRACE_syscall.kill_after_ptrace
[ RUN      ] global.get_metadata
seccomp_bpf.c:2923:global.get_metadata:Expected sizeof(md) (16) == ret (18446744073709551615)
seccomp_bpf.c:2933:global.get_metadata:Expected sizeof(md) (16) == ret (18446744073709551615)
seccomp_bpf.c:2934:global.get_metadata:Expected md.flags (2) == 0 (0)
global.get_metadata: Test failed at step #6
[     FAIL ] global.get_metadata