WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] Re: [patch 05/21] Xen-paravirt: paravirt_ops: allocate a

To: Jan Beulich <jbeulich@xxxxxxxxxx>
Subject: Re: [Xen-devel] Re: [patch 05/21] Xen-paravirt: paravirt_ops: allocate a fixmap slot
From: Andi Kleen <ak@xxxxxx>
Date: 14 Feb 2007 10:15:04 +0100
Date: Wed, 14 Feb 2007 10:15:04 +0100
Cc: Andrew Morton <akpm@xxxxxxxx>, Jeremy Fitzhardinge <jeremy@xxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxx, Dan Hecht <dhecht@xxxxxxxxxx>, linux-kernel@xxxxxxxxxxxxxxx, Chris Wright <chrisw@xxxxxxxxxxxx>, virtualization@xxxxxxxxxxxxxx
Delivery-date: Wed, 14 Feb 2007 01:14:54 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <45D2D856.76E4.0078.0@xxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <20070213221729.772002682@xxxxxxxx> <20070213221829.845132535@xxxxxxxx> <45D2649D.4080508@xxxxxxxxxx> <45D26797.5090600@xxxxxxxx> <45D2D856.76E4.0078.0@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.4.1i
On Wed, Feb 14, 2007 at 08:37:26AM +0000, Jan Beulich wrote:
> >>> Jeremy Fitzhardinge <jeremy@xxxxxxxx> 14.02.07 02:36 >>>
> >Dan Hecht wrote:
> >> Why doesn't Xen allocate the shared_info page from the pseudo-physical
> >> space?  Doesn't it already have to steal pages from the
> >> pseudo-physical space for e.g. initial page tables, console, etc?  Why
> >> not do the same for shared_info, and then you don't need a reserve the
> >> fixmap slot.
> >
> >Unlike the pagetable pages or the console page, the shared info page
> >doesn't have a pseudo-physical address, so in order to map it we need to
> >directly construct a pte containing the mfn for that page.  Inserting
> >this mapping into the fixmap space seems like the easiest way to do
> >this.  It's not like a fixmap slot costs anything.
> 
> Otoh there are many fixmap slots not used under Xen, perhaps it would
> be possible to use one of those... One slot certainly doesn't cost a lot,

I don't have a problem with reserving one page for this.

-Andi

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

<Prev in Thread] Current Thread [Next in Thread>