From mboxrd@z Thu Jan  1 00:00:00 1970
From: matteo <signorinimatteo@gmail.com>
Subject: monitoring guest sidt execution
Date: Sun, 15 Nov 2009 16:37:50 +0100
Message-ID: <4B00204E.20706@gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
To: kvm@vger.kernel.org
Return-path: <kvm-owner@vger.kernel.org>
Received: from mail-fx0-f221.google.com ([209.85.220.221]:40304 "EHLO
	mail-fx0-f221.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751754AbZKOPh7 (ORCPT <rfc822;kvm@vger.kernel.org>);
	Sun, 15 Nov 2009 10:37:59 -0500
Received: by fxm21 with SMTP id 21so1925220fxm.21
        for <kvm@vger.kernel.org>; Sun, 15 Nov 2009 07:38:03 -0800 (PST)
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

Hi to all,

 I'm trying to intercept the guest "sidt" instruction execution from the
host

i've added the bit to the control structure:


 control->intercept = | (1ULL << INTERCEPT_STORE_IDTR);

 then I have defined the sidt handler to manage the STORE_IDTR action:


 [SVM_EXIT_IDTR_READ]                    = idtr_write_interception,

 So, in the idtr_write_interception handler there is the invocation of
 the "emulate_instruction(&svm->
vcpu, kvm_run, 0, 0, 0);" function.
 Following the execution flow i found that the emulation failed in the

 x86_emulate.c source file and precisely in the "if (c->d == 0) "
 conditional statement but i really don't know why it happens and how to
 fix it.

could you please give me some hints with respect to this issue?

thanks in advance,

Matteo