Re: [Qemu-devel] [PULL 01/12] vl: Clean up user-creatable objects when exiting

[Christian Borntraeger]

This patch triggers the following crash on shutdown:


                Stack trace of thread 61598:
                #0  0x000003ff8990915e pthread_join (libpthread.so.0)
                #1  0x00000000014ddfda qemu_thread_join (qemu-system-s390x)
                #2  0x00000000011bbd68 iothread_stop (qemu-system-s390x)
                #3  0x00000000011bbe36 iothread_instance_finalize 
(qemu-system-s390x)
                #4  0x000000000135b4a4 object_deinit (qemu-system-s390x)
                #5  0x000000000135b548 object_finalize (qemu-system-s390x)
                #6  0x000000000135cc02 object_unref (qemu-system-s390x)
                #7  0x000000000135e61a object_finalize_child_property 
(qemu-system-s390x)
                #8  0x000000000135b16a object_property_del_all 
(qemu-system-s390x)
                #9  0x000000000135b536 object_finalize (qemu-system-s390x)
                #10 0x000000000135cc02 object_unref (qemu-system-s390x)
                #11 0x000000000135e61a object_finalize_child_property 
(qemu-system-s390x)
                #12 0x000000000135b2ea object_property_del_child 
(qemu-system-s390x)
                #13 0x000000000135b44a object_unparent (qemu-system-s390x)
                #14 0x0000000001362754 user_creatable_cleanup 
(qemu-system-s390x)
                #15 0x00000000011d012a main (qemu-system-s390x)
                #16 0x000003ff8972289a __libc_start_main (libc.so.6)
                #17 0x0000000001017646 _start (qemu-system-s390x)


command line parameters are long (one of my test systems)

-name guest=zhyp137,debug-threads=on -S -object 
secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-7-zhyp137/master-key.aes
 -machine 
s390-ccw-virtio-2.11,accel=kvm,usb=off,dump-guest-core=off,loadparm=PROMPT -m 
2048 -realtime mlock=off -smp 4,sockets=4,cores=1,threads=1 -object 
iothread,id=iothread1 -object iothread,id=iothread2 -object 
iothread,id=iothread3 -object iothread,id=iothread4 -object 
iothread,id=iothread5 -object iothread,id=iothread6 -object 
iothread,id=iothread7 -object iothread,id=iothread8 -object 
iothread,id=iothread9 -object iothread,id=iothread10 -object 
iothread,id=iothread11 -object iothread,id=iothread12 -object 
iothread,id=iothread13 -object iothread,id=iothread14 -object 
iothread,id=iothread15 -object iothread,id=iothread16 -object 
iothread,id=iothread17 -object iothread,id=iothread18 -object 
iothread,id=iothread19 -object iothread,id=iothread20 -uuid 
4c3ae636-529d-4d90-b203-c8d3d150f0d0 -display none -no-user-config -nodefaults 
-chardev 
socket,id=charmonitor,path=/var/lib/libvirt/qemu/domain-7-zhyp137/monitor.sock,server,nowait
 -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown 
-boot strict=on -drive 
file=/var/lib/libvirt/qemu/image.zhyp137,format=qcow2,if=none,id=drive-virtio-disk0,serial=skel,cache=none
 -device 
virtio-blk-ccw,iothread=iothread1,scsi=off,devno=fe.0.0000,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1
 -drive 
file=/var/lib/libvirt/qemu/image.zhyp137.old,format=qcow2,if=none,id=drive-virtio-disk1,serial=old,cache=none
 -device 
virtio-blk-ccw,iothread=iothread1,scsi=off,devno=fe.0.0001,drive=drive-virtio-disk1,id=virtio-disk1
 -netdev tap,fd=24,id=hostnet0,vhost=on,vhostfd=26 -device 
virtio-net-ccw,netdev=hostnet0,id=net0,mac=52:54:00:d1:cd:1c,devno=fe.0.000d 
-chardev pty,id=charconsole0 -device 
sclpconsole,chardev=charconsole0,id=console0 -device 
virtio-balloon-ccw,id=balloon0,devno=fe.3.ffba -drive 
driver=null-aio,id=null1,if=none,size=1500G -device 
virtio-blk-ccw,scsi=off,drive=null1,serial=null1,iothread=iothread16 -drive 
driver=null-aio,id=null2,if=none,size=1500G -device 
virtio-blk-ccw,scsi=off,drive=null2,serial=null2,iothread=iothread17 -drive 
driver=null-aio,id=null3,if=none,size=1500G -device 
virtio-blk-ccw,scsi=off,drive=null3,serial=null3,iothread=iothread18 -drive 
driver=null-aio,id=null4,if=none,size=1500G -device 
virtio-blk-ccw,scsi=off,drive=null4,serial=null4,iothread=iothread19 -drive 
driver=null-aio,id=null5,if=none,size=1500G -device 
virtio-blk-ccw,scsi=off,drive=null5,serial=null5,iothread=iothread20,num-queues=10
 -gdb tcp::1409 -msg timestamp=on

On 09/19/2017 10:18 PM, Eduardo Habkost wrote:
> Delete all user-creatable objects in /objects when exiting QEMU, so they
> can perform cleanup actions.
> 
> Signed-off-by: Eduardo Habkost <address@hidden>
> Message-Id: <address@hidden>
> Acked-by: Philippe Mathieu-Daudé <address@hidden>
> Tested-by: Zack Cornelius <address@hidden>
> Signed-off-by: Eduardo Habkost <address@hidden>
> ---
>  include/qom/object_interfaces.h | 8 ++++++++
>  qom/object_interfaces.c         | 5 +++++
>  vl.c                            | 1 +
>  3 files changed, 14 insertions(+)
> 
> diff --git a/include/qom/object_interfaces.h b/include/qom/object_interfaces.h
> index d63c1c28f8..d23e11bc53 100644
> --- a/include/qom/object_interfaces.h
> +++ b/include/qom/object_interfaces.h
> @@ -147,4 +147,12 @@ int user_creatable_add_opts_foreach(void *opaque,
>   */
>  void user_creatable_del(const char *id, Error **errp);
>  
> +/**
> + * user_creatable_cleanup:
> + *
> + * Delete all user-creatable objects and the user-creatable
> + * objects container.
> + */
> +void user_creatable_cleanup(void);
> +
>  #endif
> diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
> index 3bb8959f09..6824a88caa 100644
> --- a/qom/object_interfaces.c
> +++ b/qom/object_interfaces.c
> @@ -193,6 +193,11 @@ void user_creatable_del(const char *id, Error **errp)
>      object_unparent(obj);
>  }
>  
> +void user_creatable_cleanup(void)
> +{
> +    object_unparent(object_get_objects_root());
> +}
> +
>  static void register_types(void)
>  {
>      static const TypeInfo uc_interface_info = {
> diff --git a/vl.c b/vl.c
> index 9e62e92aea..ad49314608 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -4887,6 +4887,7 @@ int main(int argc, char **argv, char **envp)
>      audio_cleanup();
>      monitor_cleanup();
>      qemu_chr_cleanup();
> +    user_creatable_cleanup();
>      /* TODO: unref root container, check all devices are ok */
>  
>      return 0;
>