From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olaf Hering Subject: Re: [PATCH 0 of 5] update xenctx to dump pagetables Date: Mon, 20 Jun 2011 19:51:58 +0200 Message-ID: <20110620175158.GA17413@aepfle.de> References: <20110620173345.GO17634@whitby.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <20110620173345.GO17634@whitby.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Tim Deegan Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On Mon, Jun 20, Tim Deegan wrote: > Hi, > > At 17:26 +0200 on 20 Jun (1308590816), Olaf Hering wrote: > > The code to walk the pagetables is/was based on > > xc_translate_foreign_address(), but I still think I have some major bugs in > > there (the last patch). I cant figure out why some l3/l2/l1 entries can not be mapped. > > Any help with getting that output fixed for at least a a 64bit PV guest is much > > appreciated. > > I didn't spot anything broken in the walker (though it will need a bunch > of cleaning up) and the output looks very plausible. I take it this is > a PV guest? Is it a well-behaved one or a broken post-migrate one? Yes, its a PV guest. I cant reproduce the migrate crashes, it happens only on very few systems or on a certain configuration. The logs I posted are from my test system. Any ideas why some mfns are not accessible? Are there any other paging states maintained outside of the guests memory? > One thing that might be causing trouble is if the domain's not paused > while you do the walk, then you might see inconsistent tables, though > I'd expect them to be garbage rather than looking like this. Your patch > 3/5 does seem to make the pausing conditional where before it always > happened. It tries it preserve the state, if the guest was paused it probably should not be unpaused. Is the dominfo.paused flag somehow unreliable, I thought it comes right from struct domain?