Alex Bennée <alex.ben...@linaro.org> writes:
> Hi, > <snip> > I can replicate some of the other failures I've been seeing in CI by > running: > > ../../meson/meson.py test --repeat 10 --print-errorlogs qtest-arm/qos-test > > however this seems to run everything in parallel and maybe is better > at exposing race conditions. Perhaps the CI system makes those races > easier to hit? Unfortunately I've not been able to figure out exactly > how things go wrong in the failure case. > <snip> There is a circular call - we are in vu_gpio_stop which triggers a write to vhost-user which allows us to catch a disconnect event: #0 vhost_dev_is_started (hdev=0x557adf80d878) at /home/alex/lsrc/qemu.git/include/hw/virtio/vhost.h:199 #1 0x0000557adbe0518a in vu_gpio_stop (vdev=0x557adf80d640) at ../../hw/virtio/vhost-user-gpio.c:138 #2 0x0000557adbe04d56 in vu_gpio_disconnect (dev=0x557adf80d640) at ../../hw/virtio/vhost-user-gpio.c:255 #3 0x0000557adbe049bb in vu_gpio_event (opaque=0x557adf80d640, event=CHR_EVENT_CLOSED) at ../../hw/virtio/vhost-user-gpio.c:274 #4 0x0000557adc0539ef in chr_be_event (s=0x557adea51f10, event=CHR_EVENT_CLOSED) at ../../chardev/char.c:61 #5 0x0000557adc0506aa in qemu_chr_be_event (s=0x557adea51f10, event=CHR_EVENT_CLOSED) at ../../chardev/char.c:81 #6 0x0000557adc04f666 in tcp_chr_disconnect_locked (chr=0x557adea51f10) at ../../chardev/char-socket.c:470 #7 0x0000557adc04c81a in tcp_chr_write (chr=0x557adea51f10, buf=0x7ffe8588cce0 "\v", len=20) at ../../chardev/char-socket.c:129 #8 0x0000557adc050999 in qemu_chr_write_buffer (s=0x557adea51f10, buf=0x7ffe8588cce0 "\v", len=20, offset=0x7ffe8588cbe4, write_all=true) at ../../chardev/char.c:121 #9 0x0000557adc0507c7 in qemu_chr_write (s=0x557adea51f10, buf=0x7ffe8588cce0 "\v", len=20, write_all=true) at ../../chardev/char.c:173 #10 0x0000557adc046f3a in qemu_chr_fe_write_all (be=0x557adf80d830, buf=0x7ffe8588cce0 "\v", len=20) at ../../chardev/char-fe.c:53 #11 0x0000557adbddc02f in vhost_user_write (dev=0x557adf80d878, msg=0x7ffe8588cce0, fds=0x0, fd_num=0) at ../../hw/virtio/vhost-user.c:490 #12 0x0000557adbddd48f in vhost_user_get_vring_base (dev=0x557adf80d878, ring=0x7ffe8588d000) at ../../hw/virtio/vhost-user.c:1260 #13 0x0000557adbdd4bd6 in vhost_virtqueue_stop (dev=0x557adf80d878, vdev=0x557adf80d640, vq=0x557adf843570, idx=0) at ../../hw/virtio/vhost.c:1220 #14 0x0000557adbdd7eda in vhost_dev_stop (hdev=0x557adf80d878, vdev=0x557adf80d640, vrings=false) at ../../hw/virtio/vhost.c:1916 #15 0x0000557adbe051a6 in vu_gpio_stop (vdev=0x557adf80d640) at ../../hw/virtio/vhost-user-gpio.c:142 #16 0x0000557adbe04849 in vu_gpio_set_status (vdev=0x557adf80d640, status=15 '\017') at ../../hw/virtio/vhost-user-gpio.c:173 #17 0x0000557adbdc87ff in virtio_set_status (vdev=0x557adf80d640, val=15 '\017') at ../../hw/virtio/virtio.c:2442 #18 0x0000557adbdcbfa0 in virtio_vmstate_change (opaque=0x557adf80d640, running=false, state=RUN_STATE_SHUTDOWN) at ../../hw/virtio/virtio.c:3736 #19 0x0000557adb91ad27 in vm_state_notify (running=false, state=RUN_STATE_SHUTDOWN) at ../../softmmu/runstate.c:334 #20 0x0000557adb910e88 in do_vm_stop (state=RUN_STATE_SHUTDOWN, send_stop=false) at ../../softmmu/cpus.c:262 #21 0x0000557adb910e30 in vm_shutdown () at ../../softmmu/cpus.c:280 #22 0x0000557adb91b9c3 in qemu_cleanup () at ../../softmmu/runstate.c:827 #23 0x0000557adb522975 in qemu_default_main () at ../../softmmu/main.c:38 #24 0x0000557adb5229a8 in main (argc=27, argv=0x7ffe8588d2f8) at ../../softmmu/main.c:48 (rr) p hdev->started $9 = true (rr) info thread Id Target Id Frame * 1 Thread 2140414.2140414 (qemu-system-aar) vhost_dev_is_started (hdev=0x557adf80d878) at /home/alex/lsrc/qemu.git/include/hw/virtio/vhost.h:199 2 Thread 2140414.2140439 (qemu-system-aar) 0x0000000070000002 in syscall_traced () 3 Thread 2140414.2140442 (qemu-system-aar) 0x0000000070000002 in syscall_traced () 4 Thread 2140414.2140443 (qemu-system-aar) 0x0000000070000002 in syscall_traced () During which we eliminate the vhost_dev with a memset: Thread 1 hit Hardware watchpoint 2: *(unsigned int *) 0x557adf80da30 Old value = 2 New value = 0 __memset_avx2_unaligned_erms () at ../sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S:220 Download failed: Invalid argument. Continuing without source file ./string/../sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S. 220 ../sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S: No such file or directory. (rr) bt #0 __memset_avx2_unaligned_erms () at ../sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S:220 #1 0x0000557adbdd67f8 in vhost_dev_cleanup (hdev=0x557adf80d878) at ../../hw/virtio/vhost.c:1501 #2 0x0000557adbe04d68 in vu_gpio_disconnect (dev=0x557adf80d640) at ../../hw/virtio/vhost-user-gpio.c:256 #3 0x0000557adbe049bb in vu_gpio_event (opaque=0x557adf80d640, event=CHR_EVENT_CLOSED) at ../../hw/virtio/vhost-user-gpio.c:274 #4 0x0000557adc0539ef in chr_be_event (s=0x557adea51f10, event=CHR_EVENT_CLOSED) at ../../chardev/char.c:61 #5 0x0000557adc0506aa in qemu_chr_be_event (s=0x557adea51f10, event=CHR_EVENT_CLOSED) at ../../chardev/char.c:81 #6 0x0000557adc04f666 in tcp_chr_disconnect_locked (chr=0x557adea51f10) at ../../chardev/char-socket.c:470 #7 0x0000557adc04c81a in tcp_chr_write (chr=0x557adea51f10, buf=0x7ffe8588cce0 "\v", len=20) at ../../chardev/char-socket.c:129 #8 0x0000557adc050999 in qemu_chr_write_buffer (s=0x557adea51f10, buf=0x7ffe8588cce0 "\v", len=20, offset=0x7ffe8588cbe4, write_all=true) at ../../chardev/char.c:121 #9 0x0000557adc0507c7 in qemu_chr_write (s=0x557adea51f10, buf=0x7ffe8588cce0 "\v", len=20, write_all=true) at ../../chardev/char.c:173 #10 0x0000557adc046f3a in qemu_chr_fe_write_all (be=0x557adf80d830, buf=0x7ffe8588cce0 "\v", len=20) at ../../chardev/char-fe.c:53 #11 0x0000557adbddc02f in vhost_user_write (dev=0x557adf80d878, msg=0x7ffe8588cce0, fds=0x0, fd_num=0) at ../../hw/virtio/vhost-user.c:490 #12 0x0000557adbddd48f in vhost_user_get_vring_base (dev=0x557adf80d878, ring=0x7ffe8588d000) at ../../hw/virtio/vhost-user.c:1260 #13 0x0000557adbdd4bd6 in vhost_virtqueue_stop (dev=0x557adf80d878, vdev=0x557adf80d640, vq=0x557adf843570, idx=0) at ../../hw/virtio/vhost.c:1220 #14 0x0000557adbdd7eda in vhost_dev_stop (hdev=0x557adf80d878, vdev=0x557adf80d640, vrings=false) at ../../hw/virtio/vhost.c:1916 #15 0x0000557adbe051a6 in vu_gpio_stop (vdev=0x557adf80d640) at ../../hw/virtio/vhost-user-gpio.c:142 #16 0x0000557adbe04849 in vu_gpio_set_status (vdev=0x557adf80d640, status=15 '\017') at ../../hw/virtio/vhost-user-gpio.c:173 #17 0x0000557adbdc87ff in virtio_set_status (vdev=0x557adf80d640, val=15 '\017') at ../../hw/virtio/virtio.c:2442 #18 0x0000557adbdcbfa0 in virtio_vmstate_change (opaque=0x557adf80d640, running=false, state=RUN_STATE_SHUTDOWN) at ../../hw/virtio/virtio.c:3736 #19 0x0000557adb91ad27 in vm_state_notify (running=false, state=RUN_STATE_SHUTDOWN) at ../../softmmu/runstate.c:334 #20 0x0000557adb910e88 in do_vm_stop (state=RUN_STATE_SHUTDOWN, send_stop=false) at ../../softmmu/cpus.c:262 #21 0x0000557adb910e30 in vm_shutdown () at ../../softmmu/cpus.c:280 #22 0x0000557adb91b9c3 in qemu_cleanup () at ../../softmmu/runstate.c:827 #23 0x0000557adb522975 in qemu_default_main () at ../../softmmu/main.c:38 #24 0x0000557adb5229a8 in main (argc=27, argv=0x7ffe8588d2f8) at ../../softmmu/main.c:48 Before finally: #0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50 #1 0x00007f24dc269537 in __GI_abort () at abort.c:79 #2 0x00007f24dc26940f in __assert_fail_base (fmt=0x7f24dc3e16a8 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x557adc28d8f5 "assign || nvqs == proxy->nvqs_with_notifiers", file=0x557adc28d7ab "../../hw/virtio/virtio-pci.c", line=1029, function=<optimized out>) at assert.c:92 #3 0x00007f24dc278662 in __GI___assert_fail (assertion=0x557adc28d8f5 "assign || nvqs == proxy->nvqs_with_notifiers", file=0x557adc28d7ab "../../hw/virtio/virtio-pci.c", line=1029, function=0x557adc28d922 "int virtio_pci_set_guest_notifiers(DeviceState *, int, _Bool)") at assert.c:101 #4 0x0000557adb8e97f1 in virtio_pci_set_guest_notifiers (d=0x557adf805280, nvqs=0, assign=false) at ../../hw/virtio/virtio-pci.c:1029 #5 0x0000557adbe051c7 in vu_gpio_stop (vdev=0x557adf80d640) at ../../hw/virtio/vhost-user-gpio.c:144 #6 0x0000557adbe04849 in vu_gpio_set_status (vdev=0x557adf80d640, status=15 '\017') at ../../hw/virtio/vhost-user-gpio.c:173 #7 0x0000557adbdc87ff in virtio_set_status (vdev=0x557adf80d640, val=15 '\017') at ../../hw/virtio/virtio.c:2442 #8 0x0000557adbdcbfa0 in virtio_vmstate_change (opaque=0x557adf80d640, running=false, state=RUN_STATE_SHUTDOWN) at ../../hw/virtio/virtio.c:3736 #9 0x0000557adb91ad27 in vm_state_notify (running=false, state=RUN_STATE_SHUTDOWN) at ../../softmmu/runstate.c:334 #10 0x0000557adb910e88 in do_vm_stop (state=RUN_STATE_SHUTDOWN, send_stop=false) at ../../softmmu/cpus.c:262 #11 0x0000557adb910e30 in vm_shutdown () at ../../softmmu/cpus.c:280 #12 0x0000557adb91b9c3 in qemu_cleanup () at ../../softmmu/runstate.c:827 #13 0x0000557adb522975 in qemu_default_main () at ../../softmmu/main.c:38 #14 0x0000557adb5229a8 in main (argc=27, argv=0x7ffe8588d2f8) at ../../softmmu/main.c:48 Because of course we've just done that on disconnect. Not sure what the cleanest way to avoid that is yet. Maybe it will be clearer on Monday morning. -- Alex Bennée