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] Is machine_to_phys_mapping a 4MB 'superpage'?

To: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] Is machine_to_phys_mapping a 4MB 'superpage'?
From: Jacob Gorm Hansen <jacobg@xxxxxxx>
Date: Thu, 31 Mar 2005 00:47:52 -0800
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Thu, 31 Mar 2005 08:49:07 +0000
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <0bed8e482147a6f9f1ca051edf6b03b5@xxxxxxxxxxxx>
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: <424B6D94.1080900@xxxxxxx> <0bed8e482147a6f9f1ca051edf6b03b5@xxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mozilla Thunderbird 1.0 (X11/20050302)
Keir Fraser wrote:

On 31 Mar 2005, at 04:25, Jacob Gorm Hansen wrote:

The machine_to_phys_mapping table is mapped permanently at 0xFC000000 (on x86-32). I would like to experiment with letting the domU map it at other locations in its virtual address space, but I suppose that for performance it is mapped as a 4MB 'super' page, and as such needs special treatment, is this correct?


It doesn't *have* to be mapped as a superpage -- control tools don't when doing suspend/resume, for example. Fixing the permission checking so that other than domain0 can remap the m2p table shouldn't be very hard, but I'm not sure what the cleanest method would be.

actually I would just like for domUs to be able to map it in different locations, in order to get a little more flexible memory layout.

I will probably just try and hack something up for my immediate needs.

Jacob


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

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