[Qemu-devel] checking the number of target cpu cycles or instructions executed

[Qemu-devel] checking the number of target cpu cycles or instructions executed

[Stefano Bonifazi]

Hi all! :)
  how can I check the number of target cpu cycles or target instructions 
executed inside qemu-user (i.e. qemu-ppc)?
Is there any variable I can inspect for such informations?
Thank you very much in advance!
  Stefano B.

Re: [Qemu-devel] checking the number of target cpu cycles or instructions executed

[Andreas Färber]

Hi,

Am 22.12.2010 um 13:19 schrieb Stefano Bonifazi:

> how can I check the number of target cpu cycles or target  
> instructions executed inside qemu-user (i.e. qemu-ppc)?
> Is there any variable I can inspect for such informations?

QEMU's emulation is not cycle-accurate, so you will not be able to  
retrieve CPU cycle info to my knowledge.

As for instructions, take a look at the -icount option.

Andreas

Re: [Qemu-devel] checking the number of target cpu cycles or instructions executed

[Stefano Bonifazi]

On 12/23/2010 06:42 PM, Andreas Färber wrote:
> Hi,
>
> Am 22.12.2010 um 13:19 schrieb Stefano Bonifazi:
>
>> how can I check the number of target cpu cycles or target 
>> instructions executed inside qemu-user (i.e. qemu-ppc)?
>> Is there any variable I can inspect for such informations?
>
> QEMU's emulation is not cycle-accurate, so you will not be able to 
> retrieve CPU cycle info to my knowledge.
>
> As for instructions, take a look at the -icount option.
>
> Andreas
Hi!
  Thank You very much! I understood it was not a cycle accurate 
emulator.. In my case I am more interested in how many instructions the 
target machine would execute rather than how many host cycles or 
instructions..so I think counted fetched target instructions can be good..
Anyway how to switch on -icount option for user emulation? Setting 
use_icount to 1 (or2) into exec.c does not work: the execution hangs, 
and qemu_icount is not incremented..
Thank you!
Best Regards,
Stefano B.