WARNING - OLD ARCHIVES

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/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

RE: [Xen-devel] debug logging in windows

To: "Steven Smith" <steven.smith@xxxxxxxxxx>
Subject: RE: [Xen-devel] debug logging in windows
From: "James Harper" <james.harper@xxxxxxxxxxxxxxxx>
Date: Thu, 13 Nov 2008 14:08:43 +1100
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Wed, 12 Nov 2008 19:09:09 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <20081113030128.GA18035@xxxxxxxxxxxxxxxxxxxxxxxxxx>
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: <AEC6C66638C05B468B556EA548C1A77D0154FB11@trantor> <20081110181659.GC8252@xxxxxxxxxxxxxxxxxxxxxxxxxx> <AEC6C66638C05B468B556EA548C1A77D0154FB44@trantor> <20081113030128.GA18035@xxxxxxxxxxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AclFPG8nawy+9gREQg25GEk4k28qJQAADlbg
Thread-topic: [Xen-devel] debug logging in windows
> 
> > Is there something similar implemented via hvm/qemu that can log via
hvm
> > log files? That would make life easier. If not, I'll implement it.
> There isn't at the moment, at least not in the xenbits repositories.
> There is one in the XenServer version of qemu, though.  I've attached
> the relevant patch.  If you apply this and rebuild qemu then you
> should be able to send stuff to the qemu logfile by writing bytes to
> port 0x12.  Note that this is rate limited, though, and if you hit the
> limiter the domain will be quite severely punished.
> 
> I've checked that this applies against qemu-xen-unstable.git, and that
> the resulting tree at least builds, but I've not actually checked that
> it works.  Upstream qemu is pretty similar to XenServer qemu at the
> moment, though, so it should be okay.

I'll have a look at that one. I have actually just implemented the same
sort of thing but trapping writes to the platform pci io space. It's
just for debugging so I haven't done rate limiting or anything.

A port 0x12 debugger would be better as I could log stuff even before
the Xen PCI ioport range is mapped.

> 
> > Currently, 'xm save' appears to work but after 'xm restore' the DomU
is
> > hanging at some really strange points (eg between one KdPrint
statement
> > and the next), so I suspect that something else is going on but I'm
> > never getting the debug output because it's crashed so hard that
even
> > the windows debugger can't talk to me anymore. At least if I was
doing
> > outb's the logging would be done synchronously and I wouldn't have
the
> > debugger connected which I think is introducing a heisenbug
effect...
> Can't help you with that, sorry.
> 

Well hopefully you have :)

Thanks

James

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