From owner-freebsd-amd64@FreeBSD.ORG  Tue Nov  4 08:46:38 2014
Return-Path: <owner-freebsd-amd64@FreeBSD.ORG>
Delivered-To: freebsd-amd64@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id 7DB10AF8;
 Tue,  4 Nov 2014 08:46:38 +0000 (UTC)
Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1])
 (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id E17737EE;
 Tue,  4 Nov 2014 08:46:37 +0000 (UTC)
Received: from tom.home (kostik@localhost [127.0.0.1])
 by kib.kiev.ua (8.14.9/8.14.9) with ESMTP id sA48kU5o057730
 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO);
 Tue, 4 Nov 2014 10:46:30 +0200 (EET)
 (envelope-from kostikbel@gmail.com)
DKIM-Filter: OpenDKIM Filter v2.9.2 kib.kiev.ua sA48kU5o057730
Received: (from kostik@localhost)
 by tom.home (8.14.9/8.14.9/Submit) id sA48kSZF057727;
 Tue, 4 Nov 2014 10:46:28 +0200 (EET)
 (envelope-from kostikbel@gmail.com)
X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com
 using -f
Date: Tue, 4 Nov 2014 10:46:28 +0200
From: Konstantin Belousov <kostikbel@gmail.com>
To: John Baldwin <jhb@freebsd.org>
Subject: Re: memory type e820
Message-ID: <20141104084628.GN53947@kib.kiev.ua>
References: <CABv3qbEuggLT=9vsHAs5Rdp8a0V-=DG7DnPO1BQk4Ghn4r_9Dw@mail.gmail.com>
 <201410301353.05185.jhb@freebsd.org>
 <CABv3qbHQEFZiQ4p+HWZNLt0MiNnHBmDW1aTFhWB7vhr4J3BGfQ@mail.gmail.com>
 <3381641.WgZAz21Lfu@pippin.baldwin.cx>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <3381641.WgZAz21Lfu@pippin.baldwin.cx>
User-Agent: Mutt/1.5.23 (2014-03-12)
X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00,
 DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no
 autolearn_force=no version=3.4.0
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on tom.home
Cc: freebsd-amd64@freebsd.org
X-BeenThere: freebsd-amd64@freebsd.org
X-Mailman-Version: 2.1.18-1
Precedence: list
List-Id: Porting FreeBSD to the AMD64 platform <freebsd-amd64.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-amd64>,
 <mailto:freebsd-amd64-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-amd64/>
List-Post: <mailto:freebsd-amd64@freebsd.org>
List-Help: <mailto:freebsd-amd64-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-amd64>,
 <mailto:freebsd-amd64-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 04 Nov 2014 08:46:38 -0000

On Mon, Nov 03, 2014 at 01:52:44PM -0500, John Baldwin wrote:
> On Saturday 01 November 2014 18:55:53 Sourish Mazumder wrote:
> > Hi John,
> > 
> > I tried the pmap_mapdev() as suggested by you. Works perfectly. Thanks for
> > the information.
> 
> Sure.
> 
> > What is required, If I want to add this nvram memory to VM pages?
> 
> Hmm.  If this is device memory you generally don't want that.  I'm not 
> actually sure how to do this at runtime.  If you don't mind having a local
> hack you can add a change in the MD startup code (e.g. in hammer_time()
> in sys/amd64/amd64/machdep.c) to adjust the ranges added to
> phys_avail[] and dump_avail[].

The facility exists to do this.  It is OBJT_MGTDEVICE pager and
vm_phys_fictitious_reg_range().  This is used by i915 and TTM for
aperture, and seems XEN dom0 code uses it for mapping pages from
other domains into dom0.