From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Byrne Subject: Re: Live migration leaves page tables read-only? Date: Tue, 28 Nov 2006 18:52:41 -0800 Message-ID: <456CF5F9.7070009@hp.com> References: <456CD0A5.1060701@hp.com> <456CD2DC.2020201@hp.com> <8A87A9A84C201449A0C56B728ACF491E01FA12@liverpoolst.ad.cl.cam.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <8A87A9A84C201449A0C56B728ACF491E01FA12@liverpoolst.ad.cl.cam.ac.uk> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ian Pratt Cc: xen-devel List-Id: xen-devel@lists.xenproject.org Ian Pratt wrote: >> I forgot to mention that a very simple test case I wrote using shared >> memory and the mprotect call didn't fail. So, the only test case I > have >> at the moment is to run SAP. > > What happens if you use non-live relo? I thought I had tested that way back at the beginning without seeing the problem, but I must not have, because I just retested it to be sure and it died the same way. (Now I am truly confused and I need to go back and re-examine some of my earlier experiments.) In the meantime, any ideas where to look? > > Also, can you repro on 32b? I am doing this on behalf of someone else, so I'd have to ask them to do the setup if they have the time. I am reluctant to do so at this point. Thanks, John > > Thanks, > Ian > > >> John Byrne >> >> John Byrne wrote: >>> I have been trying to debug a problem live-migrating SAP on > Xen-3.0.3 >>> x86-64 (I also tested Xen-unstable changeset 12548) without success. >>> >>> SAP seems to run fine on a given host; live-migrating it to another > host >>> causes the guest to almost immediately panic in the mprotect() call > in >>> the change_pte_range() routine in the set_pte_at() macro because the >>> page table page it is trying to update is write-protected. >>> >>> My attempts at understanding where this is coming from have come to >>> naught. Any help in running this down would be appreciated. I am >>> perfectly willing/able to write some debugging code if I am given a > few >>> clues what to look for. >>> >>> Thanks, >>> >>> John Byrne >>> >>> >>> >>> >>> _______________________________________________ >>> Xen-devel mailing list >>> Xen-devel@lists.xensource.com >>> http://lists.xensource.com/xen-devel >>> >> >> _______________________________________________ >> Xen-devel mailing list >> Xen-devel@lists.xensource.com >> http://lists.xensource.com/xen-devel >