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


[Xen-devel] New patch was Re: follow-up to guest debug support patches

To: Ian Pratt <m+Ian.Pratt@xxxxxxxxxxxx>
Subject: [Xen-devel] New patch was Re: follow-up to guest debug support patches
From: Kip Macy <kip.macy@xxxxxxxxx>
Date: Sat, 12 Mar 2005 13:22:48 -0800
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxxx, Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>, Ian.Pratt@xxxxxxxxxxxx, Christian Limpach <Christian.Limpach@xxxxxxxxxxxx>, ian.pratt@xxxxxxxxxxxx
Delivery-date: Sat, 12 Mar 2005 21:25:11 +0000
Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:references; b=UbfR2RnmR4crql9Y3m5806gzEVzPWXQbHJ6ztmXMAaEARZRJreHJDJGKK/bB/ZFrhUILNFZXY2B23c69wEIKHmDCVK4LMMGqvIRnx2zro6a0/ZYyt5e8gcyALm76+k2BkmNtuWkWt6d+cZKvxPcEWaR/fpOX91j1FITcST2rv58=
Envelope-to: xen+James.Bulpin@xxxxxxxxxxxx
In-reply-to: <A95E2296287EAD4EB592B5DEEFCE0E9D1E35F7@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
List-archive: <http://sourceforge.net/mailarchive/forum.php?forum=xen-devel>
List-help: <mailto:xen-devel-request@lists.sourceforge.net?subject=help>
List-id: List for Xen developers <xen-devel.lists.sourceforge.net>
List-post: <mailto:xen-devel@lists.sourceforge.net>
List-subscribe: <https://lists.sourceforge.net/lists/listinfo/xen-devel>, <mailto:xen-devel-request@lists.sourceforge.net?subject=subscribe>
List-unsubscribe: <https://lists.sourceforge.net/lists/listinfo/xen-devel>, <mailto:xen-devel-request@lists.sourceforge.net?subject=unsubscribe>
References: <A95E2296287EAD4EB592B5DEEFCE0E9D1E35F7@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Reply-to: Kip Macy <kip.macy@xxxxxxxxx>
Sender: xen-devel-admin@xxxxxxxxxxxxxxxxxxxxx
Updated single patch for inspection is at:


> patch1:
> It seems to be missing a way to undo the foreign mappings on exit?
No change.

> The memcpy copying the user_ctxt is now after if gets used (addtl.
> VMX checks)  Looks like he wasn't too careful when forward
> porting -- scary :-(  Maybe the VMX check should just look at the
> context passed in.

Fixed. FYI the callers don't correctly handle the EINVAL returned there.

 > Not sure why he's skipping setting DONEFPUINIT, kernel mode and clearing
> IOPL bits though.
> Doesn't the change in traps.c break in-guest debugger support?  It seems
> to always pause the domain if it is in kernel, an in-guest debugger
> which has set a breakpoint in the kernel will never get the int3.  I
> think
> this needs some kind of flag to enable/disable this behaviour.

Long term this will be a guest boot-time / run-time settable option.
Right now, for the sake of expediency, it is xen compile-time option -
see Rules.mk.

> I think the order in arch_final_setup_guest should be:
> - check cs/ss in passed in cpu_ctxt (before doing anything)
> - update DONEFPUINIT and TF_kernel_mode flags
> - copy user_ctxt
> - copy fpu ctxt
> - clear iopl
> - exit if updating (EDF_DONEINIT)


Let me know if there is anything else I missed. Thanks.


SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
Xen-devel mailing list