From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48684) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WrXks-00066i-Ab for qemu-devel@nongnu.org; Mon, 02 Jun 2014 15:18:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WrXkh-0004nR-Cv for qemu-devel@nongnu.org; Mon, 02 Jun 2014 15:18:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:19865) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WrXkh-0004nK-0w for qemu-devel@nongnu.org; Mon, 02 Jun 2014 15:18:35 -0400 Message-ID: <1401736713.9207.143.camel@ul30vt.home> From: Alex Williamson Date: Mon, 02 Jun 2014 13:18:33 -0600 In-Reply-To: References: <20140601162414.28708.22775.stgit@bling.home> <538C52AF.4010105@msgid.tls.msk.ru> <1401715821.9207.20.camel@ul30vt.home> <538CBC0D.8000704@msgid.tls.msk.ru> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH] kvm: Enable -cpu option to hide KVM List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Bandan Das Cc: Michael Tokarev , qemu-devel@nongnu.org, kvm@vger.kernel.org On Mon, 2014-06-02 at 15:03 -0400, Bandan Das wrote: > Michael Tokarev writes: > > > 02.06.2014 17:30, Alex Williamson wrote: > >> On Mon, 2014-06-02 at 14:32 +0400, Michael Tokarev wrote: > >>> 01.06.2014 20:25, Alex Williamson wrote: > >>>> The latest Nvidia driver (337.88) specifically checks for KVM as the > >>>> hypervisor and reports Code 43 for the driver in a Windows guest when > >>>> found. Removing or changing the KVM signature is sufficient to allow > >>>> the driver to load. > >>> > >>> Hmm.. Why does it do such thing? Is it in order to prevent the driver > >>> to work in a virtualized windows, ie to prevent vga passthough to work? > >>> > >>> If that's the case, I think it is a lost game. Because they'll be adding > >>> more, cleverer, checks in the next version. > >> > >> Then they'll be pissing off more users and driving them to AMD by doing > >> so. In any case, having the ability to hide the hypervisor seems to > >> stand on it's own. What if we want to test whether a guest behavior is > >> the result of a paravirtual interface? What if a user wants to hide the > >> hypervisor in order to further reduce the exposure surface to the VM? > >> There are reasons beyond an arms race with Nvidia to want a feature like > >> this. Thanks, > > > > You answer as if I were strongly against the change. I'm not. > > What I'm against is about the reasoning. This way you're just > > accepting the arm race. > > Couldn't the arms race be a little less explicit if the commit message > is changed :) ? Why mention Nvidia at all ? Just state that the intended > application is for cases where the user might still want to run a piece > of software that bails out when KVM is detected. Would we be helping our users by omitting that from the commitlog though? Thanks, Alex