From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sheng Yang Subject: Re: [PATCH V3] perf & kvm: Enhance perf to collect KVM guest os statistics from host side Date: Tue, 20 Apr 2010 11:32:55 +0800 Message-ID: <201004201132.56039.sheng@linux.intel.com> References: <1902387910.2078.435.camel@ymzhang.sh.intel.com> <4BC9FA19.2070602@redhat.com> <4BCC136D.503@redhat.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: Joerg Roedel , "Zhang, Yanmin" , Ingo Molnar , Peter Zijlstra , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Marcelo Tosatti , Jes Sorensen , Gleb Natapov , Zachary Amsden , zhiteng.huang@intel.com, tim.c.chen@intel.com, Arnaldo Carvalho de Melo To: Avi Kivity Return-path: Received: from mga05.intel.com ([192.55.52.89]:47439 "EHLO fmsmga101.fm.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753116Ab0DTDdK (ORCPT ); Mon, 19 Apr 2010 23:33:10 -0400 In-Reply-To: <4BCC136D.503@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Monday 19 April 2010 16:25:17 Avi Kivity wrote: > On 04/17/2010 09:12 PM, Avi Kivity wrote: > > I think you were right the first time around. > > Re-reading again (esp. the part about treatment of indirect NMI > vmexits), I think this was wrong, and that the code is correct. I am > now thoroughly confused. > My fault... To my understanding now, "If an event causes a VM exit directly, it does not update architectural state as it would have if it had it not caused the VM exit:", means: in NMI case, NMI would involve the NMI handler, and change the "architectural state" to NMI block. In VMX non-root mode, the behavior of calling NMI handler changed(determine by some VMCS fields), but not the affection to the "architectural state". So the NMI block state would remain the same. -- regards Yang, Sheng