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

[Top] [All Lists]
<prev [Date] next>
[Advanced]
 <prev [Thread] next>

Re: [Xen-devel] Testing nested virtualization on Intel CPUs

from [Tim Deegan] [Permanent Link][Original]
To: AP <apxeng@xxxxxxxxx>
Subject: Re: [Xen-devel] Testing nested virtualization on Intel CPUs
From: Tim Deegan <tim@xxxxxxx>
Date: Wed, 21 Sep 2011 17:38:10 +0100
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx, Eddie Dong <eddie.dong@xxxxxxxxx>
Delivery-date: Wed, 21 Sep 2011 09:39:38 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <CAGU+autdJ0fXw2w4xmhe1Z7YZe_7H+XVr11k1-yjj9eyWMW1cA@xxxxxxxxxxxxxx>
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/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <CAGU+autjPnjevraC5vhX4RAMC2XrqkfKUN_ZuJz1r0r3078=0Q@xxxxxxxxxxxxxx> <20110920175712.GB35343@xxxxxxxxxxxxxxxxxxxxx> <CAGU+autdJ0fXw2w4xmhe1Z7YZe_7H+XVr11k1-yjj9eyWMW1cA@xxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.4.2.1i 
At 22:18 -0700 on 20 Sep (1316557136), AP wrote:
> > Yes, booting Xen as a nested guest is very slow at startup, because of
> > how Xen relocates the bottom 1MB at boot time.  You might find that
> > 32-bit Xen boots faster.
> 
> Could please expand a little on why the relocation causes it to slow down?

IIRC, the relocation itself is very slow because Xen just copies the low
1MB, which includes the VGA hole, so there are a lot of emulated reads.

Tim.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
[More with this subject...]
<Prev in Thread] Current Thread [Next in Thread>
Previous by Date:  [Xen-devel] [xen-unstable test] 8991: tolerable FAIL - PUSHED, xen . org
Next by Date:  Re: [Xen-devel] Testing nested virtualization on Intel CPUs, Alan Cox
Previous by Thread:  Re: [Xen-devel] Testing nested virtualization on Intel CPUs, AP
Next by Thread:  Re: [Xen-devel] Testing nested virtualization on Intel CPUs, Alan Cox
Indexes:  [Date] [Thread] [Top] [All Lists]
 
   

Copyright , Citrix Systems Inc. All rights reserved. Legal and Privacy