From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Deegan Subject: Re: 3.1/2 live migration panic Date: Thu, 17 Jan 2008 09:24:45 +0000 Message-ID: <20080117092445.GA15867@york.uk.xensource.com> References: <20080116223718.GA29291@totally.trollied.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com Cc: John Levon List-Id: xen-devel@lists.xenproject.org At 23:01 +0000 on 16 Jan (1200524481), Keir Fraser wrote: > Well that's a lot saner even without being a debug build. Possibly Tim has > some insight into how this can happen... I expect the 'recursive shadow > fault' is simply a result of the fault in shadow_set_l1e() causing an > unexpected re-entry into shadow code. Yep, that's exactly it. It's there to stop an unexpected #PF in the shadow code itself from being even more confusing by having the shadow code try to handle it and then fail in some other, wierder, way later. Instead, we bail out and let the normal fatal-page-fault handler take over. Tim. -- Tim Deegan Principal Software Engineer, Citrix Systems (R&D) Ltd. [Company #02300071, SL9 0DZ, UK.]