From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Joerg Roedel" Subject: Re: [PATCH] SVM: forbid guest to execute monitor/mwait Date: Thu, 22 Mar 2007 13:46:45 +0100 Message-ID: <20070322124645.GH20139@amd.com> References: <20070322095605.GB20139@amd.com> <46025528.5010707@qumranet.com> <20070322101729.GC20139@amd.com> <46025D94.8050606@qumranet.com> <20070322110733.GE20139@amd.com> <46026B2A.2080501@qumranet.com> <20070322115602.GF20139@amd.com> <4602700E.1030500@qumranet.com> <20070322122249.GG20139@amd.com> <460277AE.9040403@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: "Avi Kivity" Return-path: In-Reply-To: <460277AE.9040403-atKUWr5tajBWk0Htik3J/w@public.gmane.org> Content-Disposition: inline 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 Thu, Mar 22, 2007 at 02:33:50PM +0200, Avi Kivity wrote: > Joerg Roedel wrote: > >We agree that we should hide the monitor cpuid bit to the guest from the > >kernel level. Allowing the guest to use mwait if its available on the > >processor without proper virtualization would cause the processor to > >idle in the guest mode. > > > > I think it can be safely done from userspace, as long as host integrity is not compromised. Ok. This way is also most efficient because it does not require any further patching :) QEmu currently does not set this bit. -- Joerg Roedel Operating System Research Center AMD Saxony LLC & Co. KG ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV