From mboxrd@z Thu Jan 1 00:00:00 1970 From: jeet Subject: Re: page fault handling in Xen Date: Tue, 6 Mar 2007 18:46:17 +0530 (IST) Message-ID: <247205.9650.qm@web8815.mail.in.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser , Tim Deegan Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org =0A=0A>Above code will execute and in inner unlikely condition will be true= as PT=0A> table is read only and error is write_access=0A> and control wi= ll go to not_a_shadow_fault?=0A> =0A> so when the emulation code would be e= xecuted for the write that has been=0A> performed on read only guest PT for= adding entry in=0A> guest page table by guest?=0A> =0A> Have I missed some= thing here in understanding=0A=0A| Yes: guest PTs are mapped with write pe= rmissions in the guest PTs. It's only=0A| in the shadow PTs that the guest = PTs are mapped read-only. The test on=0A| accumulated_gflags is looking at = the access permissions in the guest PTs.=0A|=0A| -- Keir=0A=0A=0ADoes this = mean that on every new entry in level 4 guest page table will cause recursi= ve page faults =0A=0Ato create all the entries from level 4 till level 1 sh= adow page table?=0A=0AJeet=0A=0A___________________________________________= ____=0AXen-devel mailing list=0AXen-devel@lists.xensource.com=0Ahttp://list= s.xensource.com/xen-devel=0A=0A=0A=0A=0A=0A=09=09=0A_______________________= ___________________________________=0AYahoo! India Answers: Share what you = know. Learn something new=0Ahttp://in.answers.yahoo.com/