On 2012-09-19, at 7:45 AM, Jan Kiszka <[email protected]> wrote:

> On 2012-09-19 16:38, Avi Kivity wrote:
>> On 09/17/2012 10:36 PM, Dean Pucsek wrote:
>>> Hello,
>>> 
>>> For my Masters thesis I am investigating the usage of Intel VT-x and branch 
>>> tracing in the domain of malware analysis.  Essentially what I'm aiming to 
>>> do is trace the execution of a guest VM and then pass that trace on to some 
>>> other tools.  I've been playing KVM for a couple weeks now but from 
>>> comments such as (in arch/x86/kvm/vmx.c): 
>>> 
>>>       /*
>>>        * Forward all other exceptions that are valid in real mode.
>>>        * FIXME: Breaks guest debugging in real mode, needs to be fixed with
>>>        *        the required debugging infrastructure rework.
>>>        */
>>> 
>>> And (from an email sent to the list in July 2008): 
>>> 
>>>        Note that guest debugging in real mode is broken now. This has to be
>>>        fixed by the scheduled debugging infrastructure rework (will be done
>>>        once base patches for QEMU have been accepted).
>>> 
>>> it is unclear to me how much support there is for guest debugging in KVM 
>>> currently (I wasn't able to find any recent documentation on it) and what 
>>> the debugging infrastructure referred to by these comments is.  I am 
>>> interested in becoming involved with the KVM project in this respect 
>>> however some guidance and direction on the guest debugging facilities would 
>>> be greatly appreciated.
>> 
>> Guest debugging works (but not in real mode due to the issue above).
> 
> That doesn't apply to CPUs with "Unrestricted Guest" support, right? At
> least I didn't notice any limitations recently. [I did notice some other
> corner-case issue with guest debugging, still need to dig into that...]
> 
>> You can set hardware and software breakpoints and kvm will forward them
>> to userspace, and from there to the debugger.  I'll be happy to help, as
>> I'm sure Jan (as the author of most of the guest debugging code) will as
>> well.
>> 

Is there a roadmap or plan for how the KVM project envisions the debugging 
facilities evolving? 

> 
> This may help as a starter:
> 
> http://chemnitzer.linux-tage.de/2012/vortraege/folien/1061-VirtualDebugging.pdf
> 

That is a huge help, thanks!

> Jan
> 
> -- 
> Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
> Corporate Competence Center Embedded Linux

--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to