From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: ms_sysenter_eip zero value Date: Wed, 26 Jan 2011 13:24:10 +0200 Message-ID: <4D40045A.2010806@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Matteo Signorini Return-path: Received: from mx1.redhat.com ([209.132.183.28]:25575 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753113Ab1AZLYP (ORCPT ); Wed, 26 Jan 2011 06:24:15 -0500 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 01/23/2011 01:25 PM, Matteo Signorini wrote: > Hi, > > I'm having some problems understanding the sysenter instruction. > As far as I know, in order to successfully call the sysenter instruction, > MSR_IA32_SYSENTER_CS and MSR_IA32_SYSENTER_EIP registers have to be > correctly set. > > So I printed the value of such registers while the VM was running but > the output is 0 for both. > > now: > > 1) I'm having this problem ONLY with the Intel CPU (vmx.c source code). > When I run the same code on an AMD CPU (svm.c source code) > MSR_IA32_SYSENTER_EIP and MSR_IA32_SYSENTER_CS contain nonzero values. > > 2) I am 100% sure the guest is not executing an int80 but a sysenter > > so there is something here I can't understand... > please help me solving this problem. How are you printing out the values? Maybe the problem is there? -- error compiling committee.c: too many arguments to function