[Qemu-devel] State of KVM guest debugging support on Power

[Qemu-devel] State of KVM guest debugging support on Power

[Jan Kiszka]

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Hi there,

I'm generating some slides on guest debugging via kvm. What's the
current state for Book-E and Book-S? Works out of box, mostly usable, or
to be implemented? Is anyone using it?

Thanks,
Jan


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Re: [Qemu-devel] State of KVM guest debugging support on Power

[Stuart Yoder]

On Tue, Nov 1, 2011 at 9:22 AM, Jan Kiszka <jan.kiszka@web.de> wrote:
> Hi there,
>
> I'm generating some slides on guest debugging via kvm. What's the
> current state for Book-E and Book-S? Works out of box, mostly usable, or
> to be implemented? Is anyone using it?

Are you talking about guest debug using the QEMU stub or using
the virtual CPU's debug registers and interrupts?    For Freescale
Book E we have both approaches working, and patches to be sent upstream
soon.

Stuart

Re: [Qemu-devel] State of KVM guest debugging support on Power

[Alexander Graf]

On 03.11.2011, at 11:59, Stuart Yoder <b08248@gmail.com> wrote:

> On Tue, Nov 1, 2011 at 9:22 AM, Jan Kiszka <jan.kiszka@web.de> wrote:
>> Hi there,
>> 
>> I'm generating some slides on guest debugging via kvm. What's the
>> current state for Book-E and Book-S? Works out of box, mostly usable, or
>> to be implemented? Is anyone using it?
> 
> Are you talking about guest debug using the QEMU stub or using
> the virtual CPU's debug registers and interrupts?    For Freescale
> Book E we have both approaches working, and patches to be sent upstream
> soon.

For BookS I had played around with soft breakpoints for a bit, but I don't think I ever sent that upstream.

Alex

> 
> Stuart

Re: [Qemu-devel] State of KVM guest debugging support on Power

[Jan Kiszka]

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On 2011-11-03 19:59, Stuart Yoder wrote:
> On Tue, Nov 1, 2011 at 9:22 AM, Jan Kiszka <jan.kiszka@web.de> wrote:
>> Hi there,
>>
>> I'm generating some slides on guest debugging via kvm. What's the
>> current state for Book-E and Book-S? Works out of box, mostly usable, or
>> to be implemented? Is anyone using it?
> 
> Are you talking about guest debug using the QEMU stub or using
> the virtual CPU's debug registers and interrupts?    For Freescale
> Book E we have both approaches working, and patches to be sent upstream
> soon.

It's good to see both features coming into mainline.

I'll talk about the former, ie. debugging without guest help/awareness
(virtual hardware debugger). Is gdb well prepared for it (all registers
available, real-mode support, etc.)?

Thanks,
Jan


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Re: [Qemu-devel] State of KVM guest debugging support on Power

[Stuart Yoder]

On Thu, Nov 3, 2011 at 2:14 PM, Jan Kiszka <jan.kiszka@web.de> wrote:
> On 2011-11-03 19:59, Stuart Yoder wrote:
>> On Tue, Nov 1, 2011 at 9:22 AM, Jan Kiszka <jan.kiszka@web.de> wrote:
>>> Hi there,
>>>
>>> I'm generating some slides on guest debugging via kvm. What's the
>>> current state for Book-E and Book-S? Works out of box, mostly usable, or
>>> to be implemented? Is anyone using it?
>>
>> Are you talking about guest debug using the QEMU stub or using
>> the virtual CPU's debug registers and interrupts?    For Freescale
>> Book E we have both approaches working, and patches to be sent upstream
>> soon.
>
> It's good to see both features coming into mainline.
>
> I'll talk about the former, ie. debugging without guest help/awareness
> (virtual hardware debugger). Is gdb well prepared for it (all registers
> available, real-mode support, etc.)?

Right now it looks like the basic register set is available, not SPRs but not
because of any gdb limitation as far as I know.   gdb supports additional
registers with the correct target description xml file passed back to
it when it connects to the target.

In the QEMU monitor, we currently show key SPRs for 'info registers'.

As far as real mode goes, don't have direct experience with it as
everything we are doing is bookE, which has no real mode.

Stuart