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] Passing information from HVM to Xen hypervisor

To: Priyanka Tembey <tembey.priyanka@xxxxxxxxx>
Subject: Re: [Xen-devel] Passing information from HVM to Xen hypervisor
From: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
Date: Thu, 16 Sep 2010 16:04:49 +0100
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Thu, 16 Sep 2010 08:07:37 -0700
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:sender:received :in-reply-to:references:date:x-google-sender-auth:message-id:subject :from:to:cc:content-type; bh=LuqZZSgUGtbacNeYsx20sANQIlJuJqZbEcqAQs2phAA=; b=cafjTProOgnbzL/0r9M1GEiENffyzLYb1oz1+Ha56ZajH3bD3xmAtRmQMrFRN++YEa ib5dE0Z3euHKV+dzLOeh6kLAOaLHOtFx8/gHOtUE86a+s44GlI0oOJa+rJ0JO+WeHfRM XAHYVBFHkvKzMdT9sTW+4BGedgLVEL62lUIn8=
Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; b=aeH1Agsk6M7Qo40aou4+oJI2lNOAY+emJM/ICAnyJ8jJmsYTetJnP/C+6Z/wZXUMgV 68r4zYe01yHiDfPChPfj2E3TOeALyL6hZPc+BVLk5Etx5dlVg8UrPv7n8cjuGqYY4j3j efIxW618HT6eCre/Sh9MffhX5ranrC/krJ1Ao=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <AANLkTim+P8qwXV1Zwf9aSwATQfH2oe8fV8X+fE0j4Ce9@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: <AANLkTim+P8qwXV1Zwf9aSwATQfH2oe8fV8X+fE0j4Ce9@xxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
It depends on what information you want to pass.  Shared pages are
good to pass information to Xen if it's updated frequently, but Xen
doesn't necessarily need to know about each update.  (Paravirtualized
TPR would be a good example of this -- updated somtimes thoundands of
times per second, but only important if Xen is delivering an
interrupt.)

For simplicity, I'd probably say start with a hypercall, and switch to
a shared page only if the overhead of making the VMEXITs is causing a
measurable performance problem.

Are you doing scheduler work?

 -George

On Thu, Sep 16, 2010 at 3:51 PM, Priyanka Tembey
<tembey.priyanka@xxxxxxxxx> wrote:
> hello,
>
> I want to pass some information about the HVM guest kernel from the HVM
> guest to the hypervisor (specifically, the scheduler). What is the best way
> to implement this and how should I go about it (hypercall vs. shared page)?
> I was taking a look at an old post related to a similar issue
> [http://xen.1045712.n5.nabble.com/Hypercall-from-HVM-guest-td2525175.html],
> but it wasn't very conclusive.
>
> thanks,
> Priyanka
>
>
>
> _______________________________________________
> 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>