Question about tracking istructions with TCG plugin

[anton . trapanese]

Hi,
I'm running Qemu 7.0.0 in system mode, in particular I'm emulating a  
MPC8548 Power PC board, which is running an hypervisor, which is  
running two virtual boards on top.

Right now I'm interested in tracking the crashes of one of these  
virtual boards, so I inserted inside of it a bug on purpose, knowing  
that when the execution arrives at that point that specific VB is  
going to crash. When this happens, I know that the hypervisor between  
the MPC board and the VBs call a certain function, so I'm tracking  
that specific istruction with the already existing plugin "execlog"  
with the "afilter=myaddress" option.

All of this works, but there's something strange: The function i'm  
tracking shows up only when I interrupt the Qemu emulation. So just to  
be clear:

When I execute the system WITH the bug, after that specific VB crashes  
(I know when that happens because it stops printing on the serial  
port) and AFTER i manually interrupt the Qemu emulation of the full  
system, the fuction tracked shows up.

When I execute the system WITHOUT the bug, whenever I interrupt the  
Qemu emulation that fuction does not appear, beacuse of course it  
wasn't called since nothing crashed.

So as you can see, it works as intended but I do have a small problem:  
I wanted to track the execution of that instruction WHILE the system  
is still running. Honestly I don't really understand why that fuction  
gets logged only after I stop the entire system... Theoretically, when  
that specific VB crashes, the hypervisor calls that function to handle  
the VB's crash, so why does it shows up inside the log only after I  
stop the system altogether? As i mentioned earlier, I'm using the  
execlog.c plugin that is already included in Qemu without changing  
anything (i'm just filtering for a specific address using the  
'afilter' option) and if I execute that plugin without the filtering,  
it prints a lot of output WHILE the emulation is running. It's not  
like it start to print after I stop emulating.

So I wanted to hear some opinions about this. Do you think the mistake  
I'm doing lies behind Qemu itself, the plugin, or the system I'm  
emulating?

Thank you for your time, regards,
Antonio