From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH v3] KVM: MMU: lazily drop large spte Date: Wed, 6 Feb 2013 22:28:16 -0200 Message-ID: <20130207002816.GA16685@amt.cnet> References: <5110B08D.9080600@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Avi Kivity , Gleb Natapov , LKML , KVM To: Xiao Guangrong Return-path: Content-Disposition: inline In-Reply-To: <5110B08D.9080600@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.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.