Re: [Qemu-devel] in_asm substitute for accel=kvm:tcg

[Andreas Färber]

Hi,

Am 17.09.2013 13:37, schrieb Andriy Gapon:
> 
> It seems that when qemu is run with accel=kvm:tcg then -d in_asm does not
> produce anything.  At least, with the qemu and kvm that I have access to.

Are you saying that with accel=kvm:tcg when falling back to TCG, -d
in_asm does not work?

For accel=kvm it's expected not to produce any output since QEMU does
not process any Translation Blocks then.

> Is there any way to obtain equivalent logging in such a configuration?
> A note: a host and a guest are both amd64 (x86_64).

Under Linux, trace options for the kvm kernel module can be enabled via
the file system.

Regards,
Andreas

> 
> Some background.  I am trying to debug a problem with booting a FreeBSD VM.  
> If
> acceleration is not used then the VM boots just fine.  But with acceleration 
> the
> boot process hangs somewhere in FreeBSD boot loader, judging from what I see 
> on
> a screen.
> I suspect that there could be a problem with jumping from real to protected 
> mode
> or some such "exotic" environment.  To narrow down the possibilities I would
> like to examine execution trace and see where execution goes into the weeds.
> 
> Thank you very much in advance.
> 


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