From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Yang, Sheng" Subject: Re: [PATCH] mask out clflush Date: Thu, 10 Jul 2008 18:43:57 +0800 Message-ID: <200807101843.57902.sheng.yang@intel.com> References: <1215541784-26539-1-git-send-email-gcosta@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: Glauber Costa , glommer@gmail.com, avi@qumranet.com To: kvm@vger.kernel.org Return-path: Received: from mga11.intel.com ([192.55.52.93]:31690 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753758AbYGJKml (ORCPT ); Thu, 10 Jul 2008 06:42:41 -0400 In-Reply-To: <1215541784-26539-1-git-send-email-gcosta@redhat.com> Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: On Wednesday 09 July 2008 02:29:44 Glauber Costa wrote: > clflush is a non-privileged instruction that flushes the cacheline > given by its parameter, in terms of linear address. As it is > non-privileged, it is quite tricky, because a guest doing clflush > will actually be trying to flush a host kernel address. The linear address was convert to host physical address, then cache line was flushed. Of course the host physical address was used by guest at the time. I don't understand why we need to prevent guest from flushing cache line related to itself... -- Thanks Yang, Sheng