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][HVM][SVM] Reintroduce ASIDs.

To: "Biemueller, Sebastian" <Sebastian.Biemueller@xxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH][HVM][SVM] Reintroduce ASIDs.
From: Keir Fraser <keir@xxxxxxxxxxxxx>
Date: Tue, 15 May 2007 12:59:50 +0100
Delivery-date: Tue, 15 May 2007 04:58:20 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <C58DE21F058E2641A69D2FB2E49223A9AAA292@xxxxxxxxxxxxxxxxx>
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>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AceW195aW8skL4OXRuq5UwVa+odMXQAEKvso
Thread-topic: [Xen-devel] [PATCH][HVM][SVM] Reintroduce ASIDs.
User-agent: Microsoft-Entourage/11.3.3.061214
On 15/5/07 11:00, "Biemueller, Sebastian" <Sebastian.Biemueller@xxxxxxx>
wrote:

> This patch reintroduces ASID management for AMD-V.

A few more comments:
 1. Rather than adding an extra hook at every use of paging_update_cr3(),
paging_update_paging_modes(), paging_invlpg(), move those original calls
into your hook functions. Then the original invocation is simply replaced
with a call to your function, which can hide the extra work more neatly.

 2. Adding an extra function call on every vmentry is unfortunate. Why not
guarantee that any running SVM VCPU has a valid ASID at all times, even
while running inside Xen? This would mean that you would greedily allocate
an ASID as soon as you context-switch to a SVM VCPU, and also when the old
ASID becomes invalid. Then you could do your tests and VMCB-twiddling on
those less common paths, and avoid extra cost on the much more common
vmentry path.

 -- Keir


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

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