Subject: Re: pmap_remap_pages and protection (save/restore, part 1)
To: Jed Davis <jdev@panix.com>
From: Manuel Bouyer <bouyer@antioche.eu.org>
List: port-xen
Date: 09/08/2005 23:55:06
On Wed, Sep 07, 2005 at 09:20:00PM -0400, Jed Davis wrote:
> I notice that pmap_remap_pages unconditionally sets PG_RW and PG_M on
> the new PTE it creates for mapping in other domains' pages.  There
> looks to have been an attempt to copy these bits from the existing
> PTE, but that's #if 0'ed because it causes problems (the exact nature
> of which is hidden by xend, but the effect is that domain creation
> doesn't work), perhaps because in the case of IOCTL_PRIVCMD_MMAP the
> page usually hasn't been faulted in before this happens.  (My
> understanding of the i386 pmap module is not yet what it could be.)

Yes, that's probably the issue. And when I wrote it, I didn't find
a way to extract this information from UVM. As I didn't look at 
domain save/restore at this time, I just mapped it R/W.

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--