Comment 10 for bug 1964777

Thread spawn for the spice worker:

Thread 1 "qemu-system-x86" hit Breakpoint 5, __pthread_create_2_1 (newthread=0x5555572d1690, attr=0x0, start_routine=0x7ffff7e3d140, arg=0x5555572d1690) at pthread_create.c:597
597 in pthread_create.c
(gdb) info threads
  Id Target Id Frame
* 1 Thread 0x7ffff6bb5c40 (LWP 730722) "qemu-system-x86" __pthread_create_2_1 (newthread=0x5555572d1690, attr=0x0, start_routine=0x7ffff7e3d140, arg=0x5555572d1690)
    at pthread_create.c:597
  2 Thread 0x7ffff6243640 (LWP 731428) "qemu-system-x86" futex_wait (private=0, expected=2, futex_word=0x55555650df40 <qemu_global_mutex>) at ../sysdeps/nptl/futex-internal.h:146
  3 Thread 0x7ffff53c2640 (LWP 731429) "qemu-system-x86" __futex_abstimed_wait_common64 (private=0, cancel=true, abstime=0x0, op=393, expected=0, futex_word=0x5555567d4928)
    at futex-internal.c:57
(gdb) bt
#0 __pthread_create_2_1 (newthread=0x5555572d1690, attr=0x0, start_routine=0x7ffff7e3d140, arg=0x5555572d1690) at pthread_create.c:597
#1 0x00007ffff7e362f0 in spice_server_add_interface () from /lib/x86_64-linux-gnu/libspice-server.so.1
#2 0x0000555555a8c078 in qemu_spice_add_interface (sin=0x555557191c08) at ../ui/spice-core.c:874
#3 0x0000555555a8c2d1 in qemu_spice_add_display_interface (qxlin=0x555557191c08, con=0x5555567d3450) at ../ui/spice-core.c:944
#4 0x0000555555a9d533 in qxl_realize_common (qxl=0x555557191210, errp=0x7fffffffdbd0) at ../hw/display/qxl.c:2167
#5 0x0000555555a9d9bd in qxl_realize_primary (dev=0x555557191210, errp=0x7fffffffdc28) at ../hw/display/qxl.c:2218
#6 0x00005555559d1479 in pci_qdev_realize (qdev=0x555557191210, errp=0x7fffffffdca0) at ../hw/pci/pci.c:2143
#7 0x0000555555be14bf in device_set_realized (obj=0x555557191210, value=true, errp=0x7fffffffddb0) at ../hw/core/qdev.c:531
#8 0x0000555555beb318 in property_set_bool (obj=0x555557191210, v=0x55555718ee70, name=0x555555ee76a9 "realized", opaque=0x5555565a94e0, errp=0x7fffffffddb0) at ../qom/object.c:2268
#9 0x0000555555be92e7 in object_property_set (obj=0x555557191210, name=0x555555ee76a9 "realized", v=0x55555718ee70, errp=0x7fffffffddb0) at ../qom/object.c:1403
#10 0x0000555555bed785 in object_property_set_qobject (obj=0x555557191210, name=0x555555ee76a9 "realized", value=0x55555718edd0, errp=0x5555565137d0 <error_fatal>) at ../qom/qom-qobject.c:28
#11 0x0000555555be9652 in object_property_set_bool (obj=0x555557191210, name=0x555555ee76a9 "realized", value=true, errp=0x5555565137d0 <error_fatal>) at ../qom/object.c:1472
#12 0x0000555555be0d53 in qdev_realize (dev=0x555557191210, bus=0x555556935580, errp=0x5555565137d0 <error_fatal>) at ../hw/core/qdev.c:333
#13 0x0000555555be0d80 in qdev_realize_and_unref (dev=0x555557191210, bus=0x555556935580, errp=0x5555565137d0 <error_fatal>) at ../hw/core/qdev.c:340
#14 0x00005555559d176a in pci_realize_and_unref (dev=0x555557191210, bus=0x555556935580, errp=0x5555565137d0 <error_fatal>) at ../hw/pci/pci.c:2210
#15 0x00005555559d17b6 in pci_create_simple_multifunction (bus=0x555556935580, devfn=-1, multifunction=false, name=0x555555e6fb8f "qxl-vga") at ../hw/pci/pci.c:2218
#16 0x00005555559d17ea in pci_create_simple (bus=0x555556935580, devfn=-1, name=0x555555e6fb8f "qxl-vga") at ../hw/pci/pci.c:2224
#17 0x00005555559d0fb2 in pci_vga_init (bus=0x555556935580) at ../hw/pci/pci.c:1996
#18 0x0000555555aeb9a7 in pc_vga_init (isa_bus=0x555556835400, pci_bus=0x555556935580) at ../hw/i386/pc.c:981
#19 0x0000555555ad7654 in pc_q35_init (machine=0x55555676f400) at ../hw/i386/pc_q35.c:321
#20 0x0000555555ad7872 in pc_init_v6_2 (machine=0x55555676f400) at ../hw/i386/pc_q35.c:371
#21 0x00005555558e7ada in machine_run_board_init (machine=0x55555676f400) at ../hw/core/machine.c:1181
#22 0x0000555555b386e1 in qemu_init_board () at ../softmmu/vl.c:2652
#23 0x0000555555b38920 in qmp_x_exit_preconfig (errp=0x5555565137d0 <error_fatal>) at ../softmmu/vl.c:2740
#24 0x0000555555b3b1a8 in qemu_init (argc=13, argv=0x7fffffffe4a8, envp=0x7fffffffe518) at ../softmmu/vl.c:3775
#25 0x000055555580bd81 in main (argc=13, argv=0x7fffffffe4a8, envp=0x7fffffffe518) at ../softmmu/main.c:49