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[Xen-devel] Paravirtualization of the "HLT" instruction (for example) on

To: Xen Mailing List <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: [Xen-devel] Paravirtualization of the "HLT" instruction (for example) on x386
From: Ian Brown <ianbrn@xxxxxxxxx>
Date: Thu, 12 Jan 2006 11:27:31 +0200
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I am trying to understand a little more the paravirtualization
implementation in Xen.
As I understand, when using paravirtualization, we want to
change the behavior of certain instructions.
So for example, we don't want to enable guest domains to
perform "HLT" instruction (which will stop the machine).
And there are other instructions which their
default behavior in ring 1 should  be modified.

So I tried to find where in the Xen-3.0 code it is done.
I saw in vmx.c the vmx_vmexit_do_hlt() method ,which is called
when "HLT" is performed,  but this is relevant when running a
platform with VT-x.
I am looking for tracing where this handling or modifying of
the HLT instruction is done in a usual x386 (non-VTX) processor.

Can anybody please point where in the code of Xen 3.0 this is done
(for x86 processors)?

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