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] [PATCH 18/21] xenpaging: prevent page-out of first 16MB

To: "Olaf Hering" <olaf@xxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH 18/21] xenpaging: prevent page-out of first 16MB
From: "Jan Beulich" <JBeulich@xxxxxxxxxx>
Date: Fri, 17 Dec 2010 09:28:37 +0000
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Fri, 17 Dec 2010 01:31:15 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <20101216165942.GA17353@xxxxxxxxx>
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: <20101126134901.384130351@xxxxxxxxx> <20101126134907.311234491@xxxxxxxxx> <20101216165942.GA17353@xxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
>>> On 16.12.10 at 17:59, Olaf Hering <olaf@xxxxxxxxx> wrote:
> On Fri, Nov 26, Olaf Hering wrote:
> 
>> This is more a workaround than a bugfix:
>> Don't page out first 16MB of memory.
>> When the BIOS does its initialization process and xenpaging removes pages,
>> crashes will occour due to lack of support of xenpaging.
> 
> While looking at this again, I came up with this change. Any idea whats
> at 512K during BIOS startup?
> 
> 
>  Subject: xenpaging: prevent page-out of gfn 0x80
> 
> Add a workaround for missing handling of paged-out pages during BIOS 
> startup.
> For some reason, only gfn 0x80 is affected.
> 
> (XEN) HVM3: HVM Loader
> (XEN) traps.c:649:d3 Bad GMFN 80 (MFN ffffffffff) to MSR 40000000

This clearly is another place where page-in needs to be triggered.
Isn't it the case that *any* gmfn_to_mfn() needs this special
treatment? Couldn't therefore the translation function itself deal
with requesting the page-in (and waiting for its completion, now
that this can be done)?

Jan


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

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