RE: [Qemu-devel] [PATCH 1/5] single step with no IRQs and timers

RE: [Qemu-devel] [PATCH 1/5] single step with no IRQs and timers

[Wessel, Jason]

The patch is completely arch independent and should work with any of the
targets that use the gdb-stub.

Cheers,
Jason. 

> -----Original Message-----
> From: Mulyadi Santosa [mailto:a_mulyadi@softhome.net] 
> Sent: Sunday, May 21, 2006 1:54 AM
> To: qemu-devel@nongnu.org; Wessel, Jason
> Subject: Re: [Qemu-devel] [PATCH 1/5] single step with no 
> IRQs and timers
> 
> Hi Jason...
> 
> > This patch adds the functionality to the gdb-stub to single 
> step with 
> > the IRQs and timers disabled.  It greatly improves gdb's ability to 
> > perform run control while running a linux kernel and 
> stepping off of 
> > breakpoints or stepping into certain types of functions.  I 
> have also 
> > included individual controls for IRQs and timers to restore the 
> > original behavior, since it is useful as well.
> 
> Thank you very much for posting this patch. I was getting 
> trouble when doing single stepping when running linux guest 
> (2.6.14) using qemu 0.8.0, so maybe this is the right time to 
> test your patch.
> 
> BTW, this patch is non arch specific patch, right? I mean, 
> since I am using i386-softmmu, does your patch also work on 
> x86 full system emulation too?
> 
> NB: Putting this patch on qemu forum (qemu.dad-answers.com) 
> is nice while awaiting Fabrice's approval.
> 
> regards,
> 
> Mulyadi
> 
> 

Re: RE: [Qemu-devel] [PATCH 1/5] single step with no IRQs and timers

[Mulyadi Santosa]

Hi Jason..

> The patch is completely arch independent and should work with any of
> the targets that use the gdb-stub.

Just want to report that I gave it a try and it works great.

However, I am just courious, what happen if I use stepbit=0x6? That 
means: IRQ off, timer off, but single step disabled, right? Does that 
mean I am no longer able to single step? 

I tested that mask and single step still work as expected. maybe it is 
better to just ignore this specific bit (single step enabled)?

regards,

Mulyadi.

RE: RE: [Qemu-devel] [PATCH 1/5] single step with no IRQs and timers

[Wessel, Jason]

The single stepping actually only gets turned off if you do:

Qqemu.sstep=0

I am guessing you probably don't want to do this.  But as with anything
there are reasons you might, such as debugging internals of QEMU.  The
bit is in there for future use more than anything, and to maintain
compatibility with what is out there.  

I am glad to hear it works.

Jason.

> -----Original Message-----
> From: Mulyadi Santosa [mailto:a_mulyadi@softhome.net] 
> Sent: Monday, May 22, 2006 2:43 PM
> To: Wessel, Jason; qemu-devel@nongnu.org
> Subject: Re: RE: [Qemu-devel] [PATCH 1/5] single step with no 
> IRQs and timers
> 
> Hi Jason..
> 
> > The patch is completely arch independent and should work 
> with any of 
> > the targets that use the gdb-stub.
> 
> Just want to report that I gave it a try and it works great.
> 
> However, I am just courious, what happen if I use stepbit=0x6? That
> means: IRQ off, timer off, but single step disabled, right? 
> Does that mean I am no longer able to single step? 
> 
> I tested that mask and single step still work as expected. 
> maybe it is better to just ignore this specific bit (single 
> step enabled)?
> 
> regards,
> 
> Mulyadi.
> 
>