Re: hw-display-qxl.so: undefined symbol: qemu_qxl_io_log_semaphore

[Cole Robinson <crobinso@redhat.com>]

On 8/17/20 1:39 AM, Gerd Hoffmann wrote:
>   Hi,
> 
>> FWIW I'm still hitting issues with qemu-5.1.0 GA but maybe it's
>> unrelated to that specific fix. Issues reproduce on fedora 33+, not
>> fedora 32.
> 
>> +Failed to open module:
>> /builddir/build/BUILD/qemu-5.1.0-rc3/build-dynamic/x86_64-softmmu/../hw-display-qxl.so:
>> undefined symbol: qemu_qxl_client_monitors_config_crc_semaphore
> 
>> /builddir/build/BUILD/qemu-5.1.0/build-dynamic/s390x-softmmu/../hw-usb-smartcard.so:
>> undefined symbol: ccid_card_send_apdu_to_guest
> 
>> So maybe there's a more general problem. FWIW Fedora 33 started using
>> LTO by default, but it was disabled for the qemu package.
> 
> Hmm, the first looks like a problem.  I'm wondering why it happens on
> f33 only, not f32.  LTO could explain that (optimizing away symbols used
> by modules but not main qemu), but with that already turned off I have
> no clue offhand.
> 

I stripped down the reproducer. Dropping --enable-trace-backend=dtrace
makes things work AFAICT. This is on f33

dnf builddep -y qemu  # to get all the fedora package build deps
cd qemu.git
git checkout v5.1.0
./configure --target-list=x86_64-softmmu --disable-werror
--enable-modules --enable-trace-backend=dtrace
make
./x86_64-softmmu/qemu-system-x86_64 -vga qxl

# ./x86_64-softmmu/qemu-system-x86_64 -vga qxl
Failed to open module: /root/qemu.git/x86_64-softmmu/../ui-gtk.so:
undefined symbol: qemu_xkeymap_keymap_semaphore
Failed to open module: /root/qemu.git/x86_64-softmmu/../ui-sdl.so:
undefined symbol: qemu_sdl2_process_key_semaphore
Failed to open module:
/root/qemu.git/x86_64-softmmu/../hw-display-qxl.so: undefined symbol:
qemu_qxl_render_blit_semaphore
qemu-system-x86_64: QXL VGA not available

So nothing specific to qxl, seems all modules are busted.
I tried downgrading gcc to f32 versions, no difference. Same after
downgrading binutils. Downgrading glibc downgrades the whole distro so I
didn't attempt it

Output of this looks similar on f33 and f32:

nm {hw-display-qxl.so,x86_64-softmmu/qemu-system-x86_64} | grep
qemu_qxl_spice_destroy_surfaces_complete_semaphore

Any suggestions?

Thanks,
Cole