Comment 4 for bug 1920602

Attached is a minimal FreeDOS floppy disk to reproduce the TCG crash. Still reproducible with QEMU v6.0.0:

WARNING: Image format was not specified for 'test-floppy.img' and probing guessed raw.
         Automatically detecting the format is dangerous for raw images, write operations on block 0 will be restricted.
         Specify the 'raw' format explicitly to remove the restrictions.
SeaBIOS (version rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org)
Booting from Floppy...
................................................123
FreeDOS kernel 2042 (build 2042 OEM:0xfd) [compiled May 11 2016]
Kernel compatibility 7.10 - WATCOMC - FAT32 support

(C) Copyright 1995-2012 Pasquale J. Villani and The FreeDOS Project.
All Rights Reserved. This is free software and comes with ABSOLUTELY NO
WARRANTY; you can redistribute it and/or modify it under the terms of the
GNU General Public License as published by the Free Software Foundation;
either version 2, or (at your option) any later version.
 - InitDiskno hard disks detected

FreeCom version 0.84-pre2 XMS_Swap [Aug 28 2006 00:29:00]
A:\>KILLER.EXE
**
ERROR:../accel/tcg/tcg-accel-ops.c:80:tcg_handle_interrupt: assertion failed: (qemu_mutex_iothread_locked())
Bail out! ERROR:../accel/tcg/tcg-accel-ops.c:80:tcg_handle_interrupt: assertion failed: (qemu_mutex_iothread_locked())
Aborted