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Re: [Xen-devel] [RFC][PATCH] Emulate instructions in vm86 mode

To: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] [RFC][PATCH] Emulate instructions in vm86 mode
From: Bastian Blank <bastian@xxxxxxxxxxxx>
Date: Fri, 8 Sep 2006 22:58:44 +0200
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On Fri, Sep 08, 2006 at 09:37:44PM +0200, Bastian Blank wrote:
> On Thu, Sep 07, 2006 at 06:17:58PM +0100, Keir Fraser wrote:
> > The trap bounce code clears fs and gs too, just as native hardware does on
> > an exception while in vm86 mode. The real values are saved on the exception
> > stack frame (hopefully!).
> Hmm, the code write 0 for this values to the exception frame in VM86
> mode, lets check if this is the problem.

It seems that this is the problem.

The following patch always bounces traps in vm86 mode to the guest
kernel and don't longer clears the segment register values in the
exception frame.

Signed-off-by: Bastian Blank <waldi@xxxxxxxxxx>


The sooner our happiness together begins, the longer it will last.
                -- Miramanee, "The Paradise Syndrome", stardate 4842.6

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