This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-devel] How to generate a HW NMI

To: Roger Cruz <roger.cruz@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] How to generate a HW NMI
From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Date: Fri, 1 Oct 2010 10:15:23 -0400
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Fri, 01 Oct 2010 07:16:48 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <EACA7CA90354A849B1315959042A052C01146B37@xxxxxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <EACA7CA90354A849B1315959042A052C01146B37@xxxxxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.20 (2009-06-14)
On Thu, Sep 30, 2010 at 12:59:25PM -0500, Roger Cruz wrote:
> Hi fellow Xen developers,
> I continue to get system hangs where the watchdog NMI in Xen is not
> doing its job.  I am completely blind as to what is getting jammed.
> Tried multiple experiments to force the hang and in each, the watchdog
> has kicked in, so I know the mechanism works 99% of the time except in
> my one hang.
> So in the old days of PCI bus, I used to be able to generate a HW NMI by
> asserting the SERR signal in the connector.  With the advent of PCIe, I


> believe that signal is no longer present, so I am looking for any other
> way to cause a system error.    I have examined the PCI express

What about the Mini PCI-e to PCI-e adapter:

And then plug in a PCI to PCI-e adapter:


And then assert the SERR#?

> mini-card specification looking for a signal I can use in the internal
> WiFi connector, but alas, none of the signals I read about seem like
> they would do what I need.  I am not sure if there is anything I can
> short in the PCIe signals that could have a similar effect as the SERR

Per this slide deck:
it looks as if you can program the PCIe bridge to fall to "legacy" mode.

And per some folks post:

it looks as if the SERR# signal is asserted on SMBus controller?
Maybe there is a way to do it via that?

> signal.  The platform is a Lenovo T500 laptop so the number of
> connectors to play with is limited.

IBM on the server sides used to have NMI buttons - it could be that Lenova
hadn't completly gotten rid of them. Since you are open to looking at the
motherboard, maybe there is a spot marked #NMI ?

> I also thought of causing a parity/ECC error but the GM45 chipset used
> in this laptop does not support ECC memory.

> So I'm basically looking for any other ideas on how to cause a fault by
> probing somewhere in the motherboard.  This MB has a docking station
> connector but I have not been able to find the pinout list so I don't
> know what is brought out there.  At this point, I have no problem

How about just shorting the pins randomly :-)

> cracking up the case and soldering something on to the motherboard.. I
> just need to know what chips and signals to tap.
> Thanks in advance.
> Roger R. Cruz

> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel

Xen-devel mailing list

<Prev in Thread] Current Thread [Next in Thread>