From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757371Ab3BGA7I (ORCPT ); Wed, 6 Feb 2013 19:59:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:3084 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757228Ab3BGA7F (ORCPT ); Wed, 6 Feb 2013 19:59:05 -0500 Date: Wed, 6 Feb 2013 22:28:16 -0200 From: Marcelo Tosatti To: Xiao Guangrong Cc: Avi Kivity , Gleb Natapov , LKML , KVM Subject: Re: [PATCH v3] KVM: MMU: lazily drop large spte Message-ID: <20130207002816.GA16685@amt.cnet> References: <5110B08D.9080600@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5110B08D.9080600@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 05, 2013 at 03:11:09PM +0800, Xiao Guangrong wrote: > Currently, kvm zaps the large spte if write-protected is needed, the later > read can fault on that spte. Actually, we can make the large spte readonly > instead of making them un-present, the page fault caused by read access can > be avoid > > The idea is from Avi: > | As I mentioned before, write-protecting a large spte is a good idea, > | since it moves some work from protect-time to fault-time, so it reduces > | jitter. This removes the need for the return value. > > Signed-off-by: Xiao Guangrong Applied, thanks.