> On Thu, Feb 10, 2022 at 8:57 PM Parke <parke.nexus@gmail.com> wrote:
>> Is it possible to prevent QEMU from attempting to use dbus?
On Thu, Feb 10, 2022 at 9:07 AM Marc-André Lureau
<marcandre.lureau@gmail.com> wrote:
> Afaik, qemu shouldn't use dbus by default. But the gtk display might trigger a dbus path. Can you provide a backtrace of this hang?
Thanks for the tip! I tried running `strace qemu-system-x86_64
-display none`. It appears that qemu does not hang - strace prints
output indefinitely.
`-display none` may be a satisfactory workaround for me, as there is a
reasonable chance that my current project will work without a display.
Another thought I had is that maybe dbus itself is frozen and not
responding. If true, this is probably a result of the highly unusual
configuration of my system. (I generally don't use dbus. Almost all
of my GUI/X11 programs (but not qemu) are run inside custom
unprivileged user namespaces that deny access to the dbus socket.)
Below is (I think) the backtrace you requested. It appears to confirm
your suspicion of a gtk path.
(gdb) where
#0 0x00007ffff6ec8cdf in __GI___poll (fds=0x7fffffffd7e0, nfds=1,
timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x00007fffede48a73 in ?? () from /lib/x86_64-linux-gnu/libdbus-1.so.3
#2 0x00007fffede2d5ed in ?? () from /lib/x86_64-linux-gnu/libdbus-1.so.3
#3 0x00007fffede41ce4 in dbus_pending_call_block () from
/lib/x86_64-linux-gnu/libdbus-1.so.3
#4 0x00007fffede2f3be in dbus_connection_send_with_reply_and_block ()
from /lib/x86_64-linux-gnu/libdbus-1.so.3
#5 0x00007fffede2f65c in dbus_bus_register () from
/lib/x86_64-linux-gnu/libdbus-1.so.3
#6 0x00007fffeddf6da6 in atspi_get_a11y_bus () from
/lib/x86_64-linux-gnu/libatspi.so.0
#7 0x00007ffff40785cd in atk_bridge_adaptor_init () from
/lib/x86_64-linux-gnu/libatk-bridge-2.0.so.0
If you run gtk apps on a system without a bus, you probably want to remove/disable atk support. (this is pretty old code that is going away with gtk4 new accessiblity interface afaik)
#8 0x00007ffff4463710 in ?? () from /lib/x86_64-linux-gnu/libgtk-3.so.0
#9 0x00007ffff460feb7 in ?? () from /lib/x86_64-linux-gnu/libgtk-3.so.0
#10 0x00007ffff71e9c0f in g_closure_invoke () from
/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#11 0x00007ffff7205ea6 in ?? () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#12 0x00007ffff7207884 in g_signal_emit_valist () from
/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#13 0x00007ffff7207ad3 in g_signal_emit () from
/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#14 0x00007ffff71f12f4 in ?? () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#15 0x00007ffff71f992a in g_object_notify () from
/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#16 0x00007ffff42fb2eb in ?? () from /lib/x86_64-linux-gnu/libgdk-3.so.0
#17 0x00007ffff7207970 in g_signal_emit_valist () from
/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#18 0x00007ffff7207cfe in g_signal_emit_by_name () from
/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#19 0x00007ffff432cad4 in ?? () from /lib/x86_64-linux-gnu/libgdk-3.so.0
#20 0x00007ffff42fb6af in gdk_display_manager_open_display () from
/lib/x86_64-linux-gnu/libgdk-3.so.0
#21 0x00007ffff4616b7b in gtk_init_check () from
/lib/x86_64-linux-gnu/libgtk-3.so.0
#22 0x00007ffff4c8206e in ?? () from /usr/lib/x86_64-linux-gnu/qemu/ui-gtk.so
#23 0x0000555555d3547c in ?? ()
#24 0x0000555555d379bd in qemu_init ()
#25 0x000055555592dc3d in main ()