From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: Passing information from HVM to Xen hypervisor Date: Thu, 16 Sep 2010 16:04:49 +0100 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Priyanka Tembey Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org 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 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@lists.xensource.com > http://lists.xensource.com/xen-devel > >