From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: State of current pv_ops backend for KVM? Date: Wed, 30 May 2007 16:04:28 +1000 Message-ID: <1180505068.30202.88.camel@localhost.localdomain> References: <465B87CE.6030801@codemonkey.ws> <465C12C0.9030906@qumranet.com> <465C2F75.3080603@codemonkey.ws> <465C31F2.8080007@qumranet.com> <1180492544.30202.72.camel@localhost.localdomain> <465D051F.20706@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel To: Avi Kivity Return-path: In-Reply-To: <465D051F.20706-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org On Wed, 2007-05-30 at 08:01 +0300, Avi Kivity wrote: > Rusty Russell wrote: > > but it's not clear to me that verifying PTEs is that > > much faster than shadowing them if you're prepared to be that invasive > > in the guest anyway. > > > This can probably be measured on Xen which can switch from direct to > shadow mode on runtime. Sorry, I was a little oblique here. The Xen shadow mode code is aimed at supporting full virtualization, so it's not really a fair comparison. Their direct page access code hooks deep into the guest; the outstanding question is how efficient would a shadow implementation which made similar guest changes be? Unfortunately, there's a lot of coding between here and the answer 8) Rusty. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/