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] Add VMX memory-mapped Local APIC access optimiza

To: "Keir Fraser" <keir@xxxxxxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: RE: [Xen-devel] [Patch] Add VMX memory-mapped Local APIC access optimization
From: "Cui, Dexuan" <dexuan.cui@xxxxxxxxx>
Date: Thu, 31 May 2007 12:00:38 +0800
Cc: "Li, Xin B" <xin.b.li@xxxxxxxxx>, "Dong, Eddie" <eddie.dong@xxxxxxxxx>, "Nakajima, Jun" <jun.nakajima@xxxxxxxxx>
Delivery-date: Wed, 30 May 2007 20:58:58 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <C2836599.FB71%keir@xxxxxxxxxxxxx>
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: AcdrXcumBW0XNoFFTVuT/E21U2H6Bws8RBpQAqJNTp4AF98f0A==
Thread-topic: [Xen-devel] [Patch] Add VMX memory-mapped Local APIC access optimization
Keir,
Thanks a lot for the simplification!  :)
I made some simple tests, and verified at least on my host the vTPR feature 
really works and the performance of SMP Windows 2003 Guest behaves much better.

-- Dexuan

-----Original Message-----
From: Keir Fraser [mailto:keir@xxxxxxxxxxxxx] 
Sent: 2007年5月31日 0:32
To: Cui, Dexuan; xen-devel@xxxxxxxxxxxxxxxxxxx
Cc: Li, Xin B; Dong, Eddie; Nakajima, Jun
Subject: Re: [Xen-devel] [Patch] Add VMX memory-mapped Local APIC access 
optimization

Applied but I've subsequently 'simplified' it quite a bit. :-) You'll want
to pull it from the staging tree and make sure it actually still works.

 -- Keir

On 17/5/07 07:52, "Cui, Dexuan" <dexuan.cui@xxxxxxxxx> wrote:

> Some operating systems access the local APIC TPR very frequently, and we
> handle that using software-based local APIC virtualization in Xen today.
> Such virtualization incurs a number of VM exits from the memory-access
> instructions against the APIC page in the guest.
> 
> The attached patch enables the TPR shadow feature that provides APIC TPR
> virtualization in hardware. Our tests indicate it can significantly
> boost the performance of such guests including 32-bit Windows XP/2003.
> 
> Moreover, with the patch, local APIC accesses other than TPR in guests
> are intercepted directly as APIC_ACCESS VM exits rather than PAGE_FAULT
> VM exits; this can lower the emulation cost of such accesses.
> 
> Signed-off-by: Dexuan Cui <dexuan.cui@xxxxxxxxx>
> 
> PS, the related document is available in the latest Intel SDM 3B:
> http://www.intel.com/products/processor/manuals/index.htm
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel

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

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