From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Campbell Subject: Re: [BUG] XEN domU crash when PV grub chainloads 32-bit domU grub Date: Wed, 23 Sep 2015 15:18:42 +0100 Message-ID: <1443017922.10338.234.camel@citrix.com> References: <5600628A.20202@zappa.cx> <20150922223737.GK2964@var.home> <1442997251.10338.200.camel@citrix.com> <20150923124711.Horde.fWm6OM5grq3w6d8plIH4Fpd@apache.zappa.cx> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150923124711.Horde.fWm6OM5grq3w6d8plIH4Fpd@apache.zappa.cx> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Andreas Sundstrom Cc: Samuel Thibault , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On Wed, 2015-09-23 at 12:47 +0000, Andreas Sundstrom wrote: > Citerar Ian Campbell : > > > Along those lines, if the _host_ has buckets of RAM then might it be > > worth > > restricting it in case the issue is with getting MFNs which are not > > representably by the 32-bit PV interfaces? (IIRC the limit is ~160G due > > to > > the size of the m2p hole, a 32-bit MFN spans 16TB so it's unlikely to > > be > > that). > > > > Likewise maybe the issue is with full addresses which don't fit in a 32 > > -bit > > number (which is maybe more likely to happen if grub uses a 1:1 mapping > > like I would guess it does), so limiting the host to <4GB might also be > > interesting? > > > > If this was meant for me I will need more information to understand > what to test. > dom0 has either 12G or 8G memory in my test machines if that makes a > difference. It was, sorry for not being clear. How much memory do the test machines have? If it is more than 160G then try booting with "mem=160G" on the hypervisor (not Linux) command line. You can just edit that in via grub. Then try with mem=4G (which might require shrinking dom0 too of course). Ian.