From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH v7 06/11] pvqspinlock, x86: Allow unfair queue spinlock in a KVM guest Date: Thu, 20 Mar 2014 23:40:08 +0100 Message-ID: <532B6E48.2070205@redhat.com> References: <1395260049-30839-1-git-send-email-Waiman.Long@hp.com> <1395260049-30839-7-git-send-email-Waiman.Long@hp.com> <532B6543.7050707@redhat.com> <532B6BC8.8010502@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <532B6BC8.8010502@zytor.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: "H. Peter Anvin" , Waiman Long , Thomas Gleixner , Ingo Molnar , Arnd Bergmann , Peter Zijlstra Cc: Jeremy Fitzhardinge , Raghavendra K T , kvm@vger.kernel.org, Aswin Chandramouleeswaran , Andi Kleen , Michel Lespinasse , Alok Kataria , linux-arch@vger.kernel.org, Gleb Natapov , x86@kernel.org, xen-devel@lists.xenproject.org, "Paul E. McKenney" , Scott J Norton , Steven Rostedt , Chris Wright , Boris Ostrovsky , virtualization@lists.linux-foundation.org, Chegu Vinod , Oleg Nesterov , linux-kernel@vger.kernel.org, David Vrabel , Andrew Morton List-Id: linux-arch.vger.kernel.org Il 20/03/2014 23:29, H. Peter Anvin ha scritto: > > No! Please do what I asked you to do. You are not handling Hyper-V or > > VMWare. Just use X86_FEATURE_HYPERVISOR and it will cover all > > hypervisors that actually follow Intel's guidelines. > > And for those that don't, we should turn on X86_FEATURE_HYPERVISOR in > the Linux enumeration code as we do for other features we detect > independently. Yeah, but all the hypervisors we detect right now are fine. Not surprising, since Microsoft won't certify Windows on your hypervisor unless you set the bit, and KVM/Xen/VMware are all certified (Hyper-V does not go through the same certification, but sets it anyway). I got a second-hand report that VirtualBox doesn't set it---and I haven't verified that yet---but we don't even try to detect vbox right now. Paolo From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qc0-f175.google.com ([209.85.216.175]:40493 "EHLO mail-qc0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759160AbaCTWkR (ORCPT ); Thu, 20 Mar 2014 18:40:17 -0400 Message-ID: <532B6E48.2070205@redhat.com> Date: Thu, 20 Mar 2014 23:40:08 +0100 From: Paolo Bonzini MIME-Version: 1.0 Subject: Re: [PATCH v7 06/11] pvqspinlock, x86: Allow unfair queue spinlock in a KVM guest References: <1395260049-30839-1-git-send-email-Waiman.Long@hp.com> <1395260049-30839-7-git-send-email-Waiman.Long@hp.com> <532B6543.7050707@redhat.com> <532B6BC8.8010502@zytor.com> In-Reply-To: <532B6BC8.8010502@zytor.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: "H. Peter Anvin" , Waiman Long , Thomas Gleixner , Ingo Molnar , Arnd Bergmann , Peter Zijlstra Cc: Jeremy Fitzhardinge , Raghavendra K T , Gleb Natapov , Aswin Chandramouleeswaran , Andi Kleen , Michel Lespinasse , Boris Ostrovsky , linux-arch@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, xen-devel@lists.xenproject.org, "Paul E. McKenney" , Scott J Norton , Steven Rostedt , Chris Wright , Alok Kataria , virtualization@lists.linux-foundation.org, Chegu Vinod , Oleg Nesterov , linux-kernel@vger.kernel.org, David Vrabel , Andrew Morton Message-ID: <20140320224008.SKOr-cPajT3krJi_8W7C19zaMM3bm2CgQ1ys32NYuKI@z> Il 20/03/2014 23:29, H. Peter Anvin ha scritto: > > No! Please do what I asked you to do. You are not handling Hyper-V or > > VMWare. Just use X86_FEATURE_HYPERVISOR and it will cover all > > hypervisors that actually follow Intel's guidelines. > > And for those that don't, we should turn on X86_FEATURE_HYPERVISOR in > the Linux enumeration code as we do for other features we detect > independently. Yeah, but all the hypervisors we detect right now are fine. Not surprising, since Microsoft won't certify Windows on your hypervisor unless you set the bit, and KVM/Xen/VMware are all certified (Hyper-V does not go through the same certification, but sets it anyway). I got a second-hand report that VirtualBox doesn't set it---and I haven't verified that yet---but we don't even try to detect vbox right now. Paolo