[Qemu-devel] Bug report: qmp_stop() freezes QEMU

[Programmingkid]

From the cocoa interface when I select pause QEMU doesn't pause. Instead QEMU 
freezes. I have traced the problem to the qmp_stop() function. Here is the 
stack trace:

+                                                                               
                    2433 -[QemuCocoaAppController pauseQEMU:]  (in 
qemu-system-ppc) + 30  [0x1003c9a34]  cocoa.m:1049
    +                                                                           
                          2433 qmp_stop  (in qemu-system-ppc) + 105  
[0x100203b0d]  qmp.c:102
    +                                                                           
                            2433 vm_stop  (in qemu-system-ppc) + 57  
[0x100059326]  cpus.c:1798
    +                                                                           
                              2433 do_vm_stop  (in qemu-system-ppc) + 37  
[0x100057bf3]  cpus.c:930
    +                                                                           
                                2433 pause_all_vcpus  (in qemu-system-ppc) + 
119  [0x100058c36]  cpus.c:1611
    +                                                                           
                                  2433 qemu_cond_wait  (in qemu-system-ppc) + 
47  [0x1004f1855]
    +                                                                           
                                    2433 _pthread_cond_wait  (in 
libSystem.B.dylib) + 1286  [0x7fff82521881]
    +                                                                           
                                      2433 __semwait_signal  (in 
libSystem.B.dylib) + 10  [0x7fff8251da6a]

I did use git bisect to find the problem but there were several patches that 
seem to prevent OpenBIOS from running so finding the exact cause of the problem 
is difficult. The closest problem patch that may be related to this issue is 
this one:

commit 8bb93c6f99a42c2e0943bc904b283cd622d302c5
Author: Alex Bennée <address@hidden>
Date:   Wed Mar 15 14:48:25 2017 +0000

    ui/console: ensure graphic updates don't race with TCG vCPUs