From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kip Macy Subject: Re: [PATCH] disable writable pagetables on FreeBSD Date: Sat, 30 Apr 2005 08:12:46 -0700 Message-ID: References: <8b8c3df00717c8979b37a38909cc2ed0@cl.cam.ac.uk> Reply-To: Kip Macy Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <8b8c3df00717c8979b37a38909cc2ed0@cl.cam.ac.uk> Content-Disposition: inline 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 Cc: xen-devel List-Id: xen-devel@lists.xenproject.org On 4/30/05, Keir Fraser wrote: >=20 > On 30 Apr 2005, at 03:30, Kip Macy wrote: >=20 > > Presumably as a result of recent changes, FreeBSD no longer works with > > writable page tables. In the short-term I'm more interested in > > functionality than performance. This patch disables them and fixes a > > compile issue. >=20 > The obvious change is we reenabled batched wrpt mode. This requires the > guest to deal with reading page directory entries that have the present > bit (bit 0) cleared, even though that entry is logically present. :-) >=20 > You may hav eforgotten to handle this, since it was not required all > the while we were using emulation mode only. Entirely possible. There is only one place in the machine-independent code where we check for it. Removing it there doesn't help. It may require changing the machine-dependent code (I hope not, I'd rather it be a bug in my port or in xen). -Kip