From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: Re: [PATCH v2 3/10] KVM: MMU: fix direct sp's access corruptted Date: Mon, 28 Jun 2010 18:02:26 +0800 Message-ID: <4C287332.5080803@cn.fujitsu.com> References: <4C2498EC.2010006@cn.fujitsu.com> <4C249BAD.6000609@cn.fujitsu.com> <4C287081.40300@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , LKML , KVM list To: Avi Kivity Return-path: In-Reply-To: <4C287081.40300@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Avi Kivity wrote: > > Instead of adding a new bit, can you encode the protection in the direct > sp's access bits? So we'll have one sp for read-only or > writeable-but-not-dirty small pages, and another sp for > writeable-and-dirty small pages. > It looks like it can't solve all problems, it fix the access corrupted, but will cause D bit losed: mapping A and mapping B both are writable-and-dirty, when mapping A write #PF occurs, the mapping is writable, then we can't set B's D bit anymore. Anyway, i think we should re-intall the mapping when the state is changed. :-(