Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751975AbdHGRMi (ORCPT ); Mon, 7 Aug 2017 13:12:38 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:35156 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751453AbdHGRMg (ORCPT ); Mon, 7 Aug 2017 13:12:36 -0400 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 10.3 \(3273\)) Subject: Re: kvm_intel fails to load on Conroe CPUs running Linux 4.12 From: Nadav Amit In-Reply-To: <596b1df7-7fec-4acf-f19a-67ed4e1ba150@redhat.com> Date: Mon, 7 Aug 2017 10:12:33 -0700 Cc: Sebastian Rachuj , rkrcmar@redhat.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: 7bit Message-Id: References: <27ee7b1f-0390-fca2-4b9c-cfea715328e9@web.de> <596b1df7-7fec-4acf-f19a-67ed4e1ba150@redhat.com> To: Paolo Bonzini X-Mailer: Apple Mail (2.3273) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1296 Lines: 30 Paolo Bonzini wrote: > On 06/08/2017 23:23, Sebastian Rachuj wrote: >> On 06.08.2017 23:10, Paolo Bonzini wrote: >>> On 05/08/2017 21:26, Sebastian Rachuj wrote: >>>> Dear linux developers, >>>> >>>> since my upgrade from linux 4.11 to linux 4.12 the "kvm_intel" module >>>> does not load correctly anymore. "Modprobing" the kernel module gives an >>>> Input/Output error. It seems to be related to the CPU architecture and >>>> (to my knowledge) affects Conroe CPUs. I did a bisect and found the >>>> following commit as the guilty one: >>> >>> What is your cpuinfo? I tested on a Conroe Xeon X3220 (family 6, >>> model 15, stepping 11) when I posted that patch, and it did have virtual >>> NMIs. >> >> Thank you for looking into the issue. My cpuinfo is as follows: > > Looks like Intel was already differentiating virtualization features > across SKUs. Please run the attached script as root to see what other > things are different (apparently) between non-Xeon and Xeon Conroes. There may be another explanation. If I remember correctly from my days in Intel, Intel initially sold CMWA (Conroe) B-step. The next step, E-step, introduced a couple of new features, which may have included vNMI. The CPU of Sebastian appears to be B1 according to cpuinfo. Nadav