From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9CC36C4338F for ; Thu, 29 Jul 2021 19:38:36 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E76EE60C40 for ; Thu, 29 Jul 2021 19:38:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org E76EE60C40 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:49970 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m9BrW-0006Bt-LH for qemu-devel@archiver.kernel.org; Thu, 29 Jul 2021 15:38:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44644) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m9Bqt-0005Vr-Qj for qemu-devel@nongnu.org; Thu, 29 Jul 2021 15:37:55 -0400 Received: from mail-ej1-x629.google.com ([2a00:1450:4864:20::629]:39930) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1m9Bqq-0001Fr-Bn for qemu-devel@nongnu.org; Thu, 29 Jul 2021 15:37:55 -0400 Received: by mail-ej1-x629.google.com with SMTP id go31so12543688ejc.6 for ; Thu, 29 Jul 2021 12:37:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:from:date:message-id:subject:to:cc; bh=6smfPIq9jTabxQ8aVriiipvfU9ORfFONyqjF4INPnUg=; b=ZUdEBfUHHi+9M4bOaEtrSY3OJ19dNNBhAUWJ5l7c7jMHGyZu4AdOuZ/q+6fjdqoLGT AcyVfcD26253zrAIvHhcvTOiFogi10L0goj0Pa8Li37pRmkE06pioZ0azDCAx2VMW5ky BceAFqCi6W0ToDPYedteyikZWUpo3S3h9qdzOdffq82/x38e7a06yBE7r2B8KuTCQI40 zIqMPlLG6EL8G2RJi+b7AJRrOXcLBA1pxmFCXceriuynSfB5iqQaViURqv1VlHzhcDM8 epNdc7pFZy/xFs0h+M3dvsPGDbFcHnn/WJppkXFCl+6xpzD96wBGR12pAMJr3vcbo2Lx UYnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=6smfPIq9jTabxQ8aVriiipvfU9ORfFONyqjF4INPnUg=; b=DfYT17KdxQDZBwFM+fzGBIodhbvP0u/n96iei2fG/L3+Qyu7oAerBM/DxiZ/TerbYn IiFu2JUsV64NtDRm8NcgHN+dcOohNF4uruIoCGEuJM9F9nhJDXKt5DrrHOVoxeyZC1FV YhAnlhy12f2latCbu6WVydJxgwSZsUe8fMPHUIdzM3QUEhkt4I5ce6IE3IFuuZHZM0DC vH6CY4Vs+bKGbfOPz9UmeL2+Hiu7L4Q9XMa+1tBxB+23tYg4OmjLiAqJIUbQR916ol3B DVm0d7fRp5gv7IpYVxcbBwd7mLWVOQ/sPNhK7JcWUc0a4gWffjBTU6tPoytS5CfW37Tx EweQ== X-Gm-Message-State: AOAM533+CxU30hhGS00kDhSviMht6mOTVvHt8hC3OnY3D24NPK4qdEBy YhiiY3Jxivp+Rum27bWUOf8jovZI77c6yuTxqiReYLbfcVkU+A== X-Google-Smtp-Source: ABdhPJzBadgHzwygxwroURvk0G/RtzXoQATDIxUQPd1ADJGAg4P3Bd8bVcw6nvd+WU1fMjJA9JYUR+gC5Y7eNHYHATU= X-Received: by 2002:a17:906:948f:: with SMTP id t15mr6209186ejx.85.1627587470291; Thu, 29 Jul 2021 12:37:50 -0700 (PDT) MIME-Version: 1.0 From: Peter Maydell Date: Thu, 29 Jul 2021 20:37:07 +0100 Message-ID: Subject: migration-test hang, s390x host, aarch64 guest To: QEMU Developers Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2a00:1450:4864:20::629; envelope-from=peter.maydell@linaro.org; helo=mail-ej1-x629.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Richard Henderson , "Dr. David Alan Gilbert" , Juan Quintela Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" migration-test hung again during 'make check'. Process tree: ubuntu 42067 0.0 0.0 5460 3156 ? S 13:55 0:00 \_ bash -o pipefail -c echo 'MALLOC_PERTURB_=${MALLOC_PERTURB_:-$(( ${RANDOM:-0} % 255 + 1))} QTEST_QEMU_IMG=./qemu-img G_TEST_DBUS_DAEMON=/home/ubuntu/qemu/tests/dbus-vmstate-daemon.sh QTEST_QEMU_BINARY=./qemu-system-aarch64 QTEST_QEMU_STORAGE_DAEMON_BINARY=./storage-daemon/qemu-storage-daemon tests/qtest/migration-test --tap -k' && MALLOC_PERTURB_=${MALLOC_PERTURB_:-$(( ${RANDOM:-0} % 255 + 1))} QTEST_QEMU_IMG=./qemu-img G_TEST_DBUS_DAEMON=/home/ubuntu/qemu/tests/dbus-vmstate-daemon.sh QTEST_QEMU_BINARY=./qemu-system-aarch64 QTEST_QEMU_STORAGE_DAEMON_BINARY=./storage-daemon/qemu-storage-daemon tests/qtest/migration-test --tap -k -m quick < /dev/null | ./scripts/tap-driver.pl --test-name="qtest-aarch64/migration-test" ubuntu 42070 0.0 0.0 78844 3184 ? Sl 13:55 0:01 \_ tests/qtest/migration-test --tap -k -m quick ubuntu 43248 0.0 4.1 1401368 160852 ? Sl 13:55 0:03 | \_ ./qemu-system-aarch64 -qtest unix:/tmp/qtest-42070.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-42070.qmp,id=char0 -mon chardev=char0,mode=control -display none -accel kvm -accel tcg -machine virt,gic-version=max -name source,debug-threads=on -m 150M -serial file:/tmp/migration-test-SL7EkN/src_serial -cpu max -kernel /tmp/migration-test-SL7EkN/bootsect -accel qtest ubuntu 43256 0.0 1.4 1394208 57648 ? Sl 13:55 0:00 | \_ ./qemu-system-aarch64 -qtest unix:/tmp/qtest-42070.sock -qtest-log /dev/null -chardev socket,path=/tmp/qtest-42070.qmp,id=char0 -mon chardev=char0,mode=control -display none -accel kvm -accel tcg -machine virt,gic-version=max -name target,debug-threads=on -m 150M -serial file:/tmp/migration-test-SL7EkN/dest_serial -incoming unix:/tmp/migration-test-SL7EkN/migsocket -cpu max -kernel /tmp/migration-test-SL7EkN/bootsect -accel qtest ubuntu 42071 0.0 0.2 14116 11372 ? S 13:55 0:00 \_ perl ./scripts/tap-driver.pl --test-name=qtest-aarch64/migration-test Backtrace, migration-test process: Thread 2 (Thread 0x3ff8ff7f910 (LWP 42075)): #0 syscall () at ../sysdeps/unix/sysv/linux/s390/s390-64/syscall.S:53 #1 0x000002aa1d0d1c1c in qemu_futex_wait (val=, f=) at /home/ubuntu/qemu/include/qemu/futex.h:29 #2 qemu_event_wait (ev=ev@entry=0x2aa1d0fda58 ) at ../../util/qemu-thread-posix.c:480 #3 0x000002aa1d0d0884 in call_rcu_thread (opaque=opaque@entry=0x0) at ../../util/rcu.c:258 #4 0x000002aa1d0d0c32 in qemu_thread_start (args=) at ../../util/qemu-thread-posix.c:541 #5 0x000003ff90207aa8 in start_thread (arg=0x3ff8ff7f910) at pthread_create.c:463 #6 0x000003ff900fa11e in thread_start () at ../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65 Thread 1 (Thread 0x3ff905f7c00 (LWP 42070)): #0 0x000003ff90212978 in __waitpid (pid=, stat_loc=stat_loc@entry=0x2aa1d5e06bc, options=options@entry=0) at ../sysdeps/unix/sysv/linux/waitpid.c:30 #1 0x000002aa1d0a2176 in qtest_kill_qemu (s=0x2aa1d5e06b0) at ../../tests/qtest/libqtest.c:144 #2 0x000003ff903c0de6 in g_hook_list_invoke () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0 #3 #4 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:51 #5 0x000003ff9003f3ca in __GI_abort () at abort.c:79 #6 0x000003ff903fcbb2 in g_assertion_message () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0 #7 0x000003ff903fd2b4 in g_assertion_message_cmpstr () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0 #8 0x000002aa1d0a10f6 in check_migration_status (ungoals=0x3ffffdfe198, goal=0x2aa1d0d75c0 "postcopy-paused", who=0x2aa1d5dee90) at ../../tests/qtest/migration-helpers.c:146 #9 wait_for_migration_status (who=0x2aa1d5dee90, goal=, ungoals=0x3ffffdfe198) at ../../tests/qtest/migration-helpers.c:156 #10 0x000002aa1d09f610 in test_postcopy_recovery () at ../../tests/qtest/migration-test.c:773 #11 0x000003ff903fc70c in ?? () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0 #12 0x000003ff903fc648 in ?? () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0 #13 0x000003ff903fc648 in ?? () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0 #14 0x000003ff903fc648 in ?? () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0 #15 0x000003ff903fc8ee in g_test_run_suite () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0 #16 0x000003ff903fc928 in g_test_run () from /usr/lib/s390x-linux-gnu/libglib-2.0.so.0 #17 0x000002aa1d09d8f2 in main (argc=, argv=) at ../../tests/qtest/migration-test.c:1495 Backtrace, QEMU process 43248: Thread 5 (Thread 0x3ff8d7fe910 (LWP 43361)): #0 0x000003ff9d110582 in futex_abstimed_wait_cancelable (private=0, abstime=0x0, expected=0, futex_word=0x2aa1e27dfac) at ../sysdeps/unix/sysv/linux/futex-internal.h:205 #1 0x000003ff9d110582 in do_futex_wait (sem=sem@entry=0x2aa1e27dfa8, abstime=0x0) at sem_waitcommon.c:111 #2 0x000003ff9d11068c in __new_sem_wait_slow (sem=sem@entry=0x2aa1e27dfa8, abstime=0x0) at sem_waitcommon.c:181 #3 0x000003ff9d110734 in __new_sem_wait (sem=sem@entry=0x2aa1e27dfa8) at sem_wait.c:42 #4 0x000002aa1b6dfb96 in qemu_sem_wait (sem=0x2aa1e27dfa8, sem@entry=) at ../../util/qemu-thread-posix.c:357 #5 0x000002aa1aefe5b0 in postcopy_pause_return_path_thread (s=0x2aa1e27dc00) at ../../migration/migration.c:2654 #6 0x000002aa1aefe5b0 in source_return_path_thread (opaque=opaque@entry=0x2aa1e27dc00) at ../../migration/migration.c:2854 #7 0x000002aa1b6ded72 in qemu_thread_start (args=) at ../../util/qemu-thread-posix.c:541 #8 0x000003ff9d107aa8 in start_thread (arg=0x3ff8d7fe910) at pthread_create.c:463 #9 0x000003ff9cffa11e in thread_start () at ../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65 Thread 4 (Thread 0x3ff8ed42910 (LWP 43252)): #0 0x000003ff9d10d9fe in futex_wait_cancelable (private=, expected=0, futex_word=0x2aa1e49ca68) at ../sysdeps/unix/sysv/linux/futex-internal.h:88 #1 0x000003ff9d10d9fe in __pthread_cond_wait_common (abstime=0x0, mutex=0x2aa1c1a4840 , cond=0x2aa1e49ca40) at pthread_cond_wait.c:502 #2 0x000003ff9d10d9fe in __pthread_cond_wait (cond=cond@entry=0x2aa1e49ca40, mutex=mutex@entry=0x2aa1c1a4840 ) at pthread_cond_wait.c:655 #3 0x000002aa1b6df59e in qemu_cond_wait_impl (cond=0x2aa1e49ca40, mutex=0x2aa1c1a4840 , file=0x2aa1b8a93c6 "../../softmmu/cpus.c", line=) at ../../util/qemu-thread-posix.c:194 #4 0x000002aa1b40764e in qemu_wait_io_event (cpu=cpu@entry=0x2aa1e43aa50) at ../../softmmu/cpus.c:419 #5 0x000002aa1b406916 in mttcg_cpu_thread_fn (arg=arg@entry=0x2aa1e43aa50) at ../../accel/tcg/tcg-accel-ops-mttcg.c:98 #6 0x000002aa1b6ded72 in qemu_thread_start (args=) at ../../util/qemu-thread-posix.c:541 #7 0x000003ff9d107aa8 in start_thread (arg=0x3ff8ed42910) at pthread_create.c:463 #8 0x000003ff9cffa11e in thread_start () at ../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65 Thread 3 (Thread 0x3ff8f735910 (LWP 43251)): #0 0x000003ff9cfef1b0 in __GI___poll (fds=0x3ff64003620, nfds=3, timeout=) at ../sysdeps/unix/sysv/linux/poll.c:29 #1 0x000003ff9e852624 in () at /usr/lib/s390x-linux-gnu/libglib-2.0.so.0 #2 0x000003ff9e852aa8 in g_main_loop_run () at /usr/lib/s390x-linux-gnu/libglib-2.0.so.0 #3 0x000002aa1b4eaf0e in iothread_run (opaque=opaque@entry=0x2aa1df83b80) at ../../iothread.c:73 #4 0x000002aa1b6ded72 in qemu_thread_start (args=) at ../../util/qemu-thread-posix.c:541 #5 0x000003ff9d107aa8 in start_thread (arg=0x3ff8f735910) at pthread_create.c:463 #6 0x000003ff9cffa11e in thread_start () at ../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65 Thread 2 (Thread 0x3ff90037910 (LWP 43250)): #0 0x000003ff9cff52ea in syscall () at ../sysdeps/unix/sysv/linux/s390/s390-64/syscall.S:53 #1 0x000002aa1b6dfd5c in qemu_futex_wait (val=, f=) at /home/ubuntu/qemu/include/qemu/futex.h:29 #2 0x000002aa1b6dfd5c in qemu_event_wait (ev=ev@entry=0x2aa1c1c3888 ) at ../../util/qemu-thread-posix.c:480 #3 0x000002aa1b6d917c in call_rcu_thread (opaque=opaque@entry=0x0) at ../../util/rcu.c:258 #4 0x000002aa1b6ded72 in qemu_thread_start (args=) at ../../util/qemu-thread-posix.c:541 #5 0x000003ff9d107aa8 in start_thread (arg=0x3ff90037910) at pthread_create.c:463 #6 0x000003ff9cffa11e in thread_start () at ../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65 Thread 1 (Thread 0x3ff9feb5470 (LWP 43248)): #0 0x000003ff9cfef302 in __GI_ppoll (fds=0x2aa1ed28d00, nfds=6, timeout=, timeout@entry=0x3fff517ecf8, sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39 #1 0x000002aa1b701fec in ppoll (__ss=0x0, __timeout=0x3fff517ecf8, __nfds=, __fds=) at /usr/include/s390x-linux-gnu/bits/poll2.h:77 #2 0x000002aa1b701fec in qemu_poll_ns (fds=, nfds=, timeout=timeout@entry=1000000000) at ../../util/qemu-timer.c:348 #3 0x000002aa1b6d2f98 in os_host_main_loop_wait (timeout=1000000000) at ../../util/main-loop.c:250 #4 0x000002aa1b6d2f98 in main_loop_wait (nonblocking=nonblocking@entry=0) at ../../util/main-loop.c:531 #5 0x000002aa1b496d44 in qemu_main_loop () at ../../softmmu/runstate.c:726 #6 0x000002aa1ae6d3f0 in main (argc=, argv=, envp=) at ../../softmmu/main.c:50 Backtrace, QEMU process 43256: Thread 6 (Thread 0x3ff726ff910 (LWP 43440)): #0 0x000003ffb9f10582 in futex_abstimed_wait_cancelable (private=0, abstime=0x0, expected=0, futex_word=0x2aa1a75d2d4) at ../sysdeps/unix/sysv/linux/futex-internal.h:205 #1 0x000003ffb9f10582 in do_futex_wait (sem=sem@entry=0x2aa1a75d2d0, abstime=0x0) at sem_waitcommon.c:111 #2 0x000003ffb9f1068c in __new_sem_wait_slow (sem=sem@entry=0x2aa1a75d2d0, abstime=0x0) at sem_waitcommon.c:181 #3 0x000003ffb9f10734 in __new_sem_wait (sem=sem@entry=0x2aa1a75d2d0) at sem_wait.c:42 #4 0x000002aa17ddfb96 in qemu_sem_wait (sem=sem@entry=0x2aa1a75d2d0) at ../../util/qemu-thread-posix.c:357 #5 0x000002aa17599f06 in postcopy_pause_incoming (mis=) at ../../migration/savevm.c:2600 #6 0x000002aa17599f06 in qemu_loadvm_state_main (f=f@entry=0x2aa1a751610, mis=mis@entry=0x2aa1a75d130) at ../../migration/savevm.c:2674 #7 0x000002aa1759af4a in postcopy_ram_listen_thread (opaque=opaque@entry=0x0) at ../../migration/savevm.c:1872 #8 0x000002aa17dded72 in qemu_thread_start (args=) at ../../util/qemu-thread-posix.c:541 #9 0x000003ffb9f07aa8 in start_thread (arg=0x3ff726ff910) at pthread_create.c:463 #10 0x000003ffb9dfa11e in thread_start () at ../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65 Thread 5 (Thread 0x3ff88ffe910 (LWP 43439)): #0 0x000003ffb9f10582 in futex_abstimed_wait_cancelable (private=0, abstime=0x0, expected=0, futex_word=0x2aa1a75d2fc) at ../sysdeps/unix/sysv/linux/futex-internal.h:205 #1 0x000003ffb9f10582 in do_futex_wait (sem=sem@entry=0x2aa1a75d2f8, abstime=0x0) at sem_waitcommon.c:111 #2 0x000003ffb9f1068c in __new_sem_wait_slow (sem=sem@entry=0x2aa1a75d2f8, abstime=0x0) at sem_waitcommon.c:181 #3 0x000003ffb9f10734 in __new_sem_wait (sem=sem@entry=0x2aa1a75d2f8) at sem_wait.c:42 #4 0x000002aa17ddfb96 in qemu_sem_wait (sem=0x2aa1a75d2f8, sem@entry=) at ../../util/qemu-thread-posix.c:357 #5 0x000002aa177ae6aa in postcopy_pause_fault_thread (mis=) at ../../migration/postcopy-ram.c:847 #6 0x000002aa177ae6aa in postcopy_ram_fault_thread (opaque=opaque@entry=0x2aa1a75d130) at ../../migration/postcopy-ram.c:911 #7 0x000002aa17dded72 in qemu_thread_start (args=) at ../../util/qemu-thread-posix.c:541 #8 0x000003ffb9f07aa8 in start_thread (arg=0x3ff88ffe910) at pthread_create.c:463 #9 0x000003ffb9dfa11e in thread_start () at ../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65 Thread 4 (Thread 0x3ff89b18910 (LWP 43271)): Python Exception PC not saved: Thread 3 (Thread 0x3ff8a319910 (LWP 43270)): #0 0x000003ffb9def1b0 in __GI___poll (fds=0x3ff84003620, nfds=3, timeout=) at ../sysdeps/unix/sysv/linux/poll.c:29 #1 0x000003ffbb652624 in () at /usr/lib/s390x-linux-gnu/libglib-2.0.so.0 #2 0x000003ffbb652aa8 in g_main_loop_run () at /usr/lib/s390x-linux-gnu/libglib-2.0.so.0 #3 0x000002aa17beaf0e in iothread_run (opaque=opaque@entry=0x2aa1a3aeb80) at ../../iothread.c:73 #4 0x000002aa17dded72 in qemu_thread_start (args=) at ../../util/qemu-thread-posix.c:541 #5 0x000003ffb9f07aa8 in start_thread (arg=0x3ff8a319910) at pthread_create.c:463 #6 0x000003ffb9dfa11e in thread_start () at ../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65 Thread 2 (Thread 0x3fface37910 (LWP 43267)): #0 0x000003ffb9df52ea in syscall () at ../sysdeps/unix/sysv/linux/s390/s390-64/syscall.S:53 #1 0x000002aa17ddfd5c in qemu_futex_wait (val=, f=) at /home/ubuntu/qemu/include/qemu/futex.h:29 #2 0x000002aa17ddfd5c in qemu_event_wait (ev=ev@entry=0x2aa188c3888 ) at ../../util/qemu-thread-posix.c:480 #3 0x000002aa17dd917c in call_rcu_thread (opaque=opaque@entry=0x0) at ../../util/rcu.c:258 #4 0x000002aa17dded72 in qemu_thread_start (args=) at ../../util/qemu-thread-posix.c:541 #5 0x000003ffb9f07aa8 in start_thread (arg=0x3fface37910) at pthread_create.c:463 #6 0x000003ffb9dfa11e in thread_start () at ../sysdeps/unix/sysv/linux/s390/s390-64/clone.S:65 Thread 1 (Thread 0x3ffbccb5470 (LWP 43256)): #0 0x000003ffb9f0d9fe in futex_wait_cancelable (private=, expected=0, futex_word=0x2aa188a47e8 ) at ../sysdeps/unix/sysv/linux/futex-internal.h:88 #1 0x000003ffb9f0d9fe in __pthread_cond_wait_common (abstime=0x0, mutex=0x2aa188a4840 , cond=0x2aa188a47c0 ) at pthread_cond_wait.c:502 #2 0x000003ffb9f0d9fe in __pthread_cond_wait (cond=cond@entry=0x2aa188a47c0 , mutex=mutex@entry=0x2aa188a4840 ) at pthread_cond_wait.c:655 #3 0x000002aa17ddf59e in qemu_cond_wait_impl (cond=0x2aa188a47c0 , mutex=0x2aa188a4840 , file=0x2aa17fa93c6 "../../softmmu/cpus.c", line=) at ../../util/qemu-thread-posix.c:194 #4 0x000002aa17b079e2 in pause_all_vcpus () at ../../softmmu/cpus.c:562 #5 0x000002aa17b07aec in do_vm_stop (state=state@entry=RUN_STATE_SHUTDOWN, send_stop=send_stop@entry=false) at ../../softmmu/cpus.c:261 #6 0x000002aa17b07bb6 in vm_shutdown () at ../../softmmu/cpus.c:280 #7 0x000002aa17b9716e in qemu_cleanup () at ../../softmmu/runstate.c:812 #8 0x000002aa1756d3f6 in main (argc=, argv=, envp=) at ../../softmmu/main.c:51 No, I dunno why thread 4 was odd. Backtracing that thread seems to only work about one time in two. Here's the backtrace from a success: #0 0x000002aa17b1ca2e in load_memop (op=MO_8, haddr=0x3ff80c6d000) at ../../accel/tcg/cputlb.c:1860 #1 0x000002aa17b1ca2e in load_helper (full_load=, code_read=false, op=MO_8, retaddr=4396070052416, oi=, addr=1177997312, env=0x2aa1a86f890) at ../../accel/tcg/cputlb.c:1980 #2 0x000002aa17b1ca2e in full_ldub_mmu (env=0x2aa1a86f890, addr=1177997312, oi=, retaddr=4396070052416) at ../../accel/tcg/cputlb.c:1996 #3 0x000003ff8a31a35e in code_gen_buffer () #4 0x000002aa17bbabb4 in cpu_tb_exec (tb_exit=, itb=, cpu=) at ../../accel/tcg/cpu-exec.c:353 #5 0x000002aa17bbabb4 in cpu_loop_exec_tb (tb_exit=, last_tb=, tb=, cpu=) at ../../accel/tcg/cpu-exec.c:812 #6 0x000002aa17bbabb4 in cpu_exec (cpu=) at ../../accel/tcg/cpu-exec.c:970 #7 0x000002aa18764620 in () -- PMM