From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1E84C433DF for ; Wed, 27 May 2020 01:05:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9054F2088E for ; Wed, 27 May 2020 01:05:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="AW8Ue0LA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728055AbgE0BFS (ORCPT ); Tue, 26 May 2020 21:05:18 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:36878 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727897AbgE0BFR (ORCPT ); Tue, 26 May 2020 21:05:17 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 04R0xDgx055249; Wed, 27 May 2020 01:03:49 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2020-01-29; bh=85pK4/81/vdgWfeIJ9uroYFrDxnQQi6IhHVRzvciCac=; b=AW8Ue0LA7LdmoDkdjWSZjA5spDniRFTQgW4ssrBQgJDwI8YIY2i1Y8PXWqEUsHlVjJwS nqYYyyhHmpoxXnqQOhdyAphWhvDOmWeQS67kKlZzMpDzWR4/c9Cui0h4ZA7jhZI6f4aU YbFwKxtwcg7oM6nKdKsBAaB2b44yW6d0bXBZ0jxQXj6B8yk25mu0I+6PS5a3WbetQ1MG CZAvuCZjaXHrtvKQH9MXiLkQ069OcqTZdJPEZJo5FulJpiTIlPvumEUI/jU3YOQGOtu1 TWA6LmUxsd2s+4/l0FGWKsg/9B0hCDc+1vfcLpxLjQ1ncgC4eeJAH/Xe/xHuJrP0uS1N Yg== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 318xe1cskk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 27 May 2020 01:03:49 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 04R0vXX6129965; Wed, 27 May 2020 01:03:48 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3020.oracle.com with ESMTP id 317dktf6jn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 27 May 2020 01:03:48 +0000 Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 04R13eJA007736; Wed, 27 May 2020 01:03:40 GMT Received: from localhost.localdomain (/10.159.156.18) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 26 May 2020 18:03:40 -0700 Subject: Re: [PATCH 0/2] Fix issue with not starting nesting guests on my system To: Maxim Levitsky , kvm@vger.kernel.org Cc: Paolo Bonzini , "H. Peter Anvin" , Tao Xu , Sean Christopherson , Jim Mattson , linux-kernel@vger.kernel.org, Joerg Roedel , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , Wanpeng Li , Ingo Molnar , Thomas Gleixner , Borislav Petkov , Vitaly Kuznetsov , Jingqi Liu References: <20200523161455.3940-1-mlevitsk@redhat.com> From: Krish Sadhukhan Message-ID: Date: Tue, 26 May 2020 18:03:32 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20200523161455.3940-1-mlevitsk@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9633 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 malwarescore=0 bulkscore=0 spamscore=0 suspectscore=0 mlxscore=0 adultscore=0 mlxlogscore=984 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2005270002 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9633 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 mlxlogscore=999 adultscore=0 cotscore=-2147483648 mlxscore=0 bulkscore=0 priorityscore=1501 phishscore=0 lowpriorityscore=0 malwarescore=0 clxscore=1011 impostorscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2005270002 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 5/23/20 9:14 AM, Maxim Levitsky wrote: > On my AMD machine I noticed that I can't start any nested guests, > because nested KVM (everything from master git branches) complains > that it can't find msr MSR_IA32_UMWAIT_CONTROL which my system doesn't support > at all anyway. > > I traced it to the recently added UMWAIT support to qemu and kvm. > The kvm portion exposed the new MSR in KVM_GET_MSR_INDEX_LIST without > checking that it the underlying feature is supported in CPUID. > It happened to work when non nested because as a precation kvm, > tries to read each MSR on host before adding it to that list, > and when read gets a #GP it ignores it. > > When running nested, the L1 hypervisor can be set to ignore unknown > msr read/writes (I need this for some other guests), thus this safety > check doesn't work anymore. > > V2: * added a patch to setup correctly the X86_FEATURE_WAITPKG kvm capability > * dropped the cosmetic fix patch as it is now fixed in kvm/queue > > Best regards, > Maxim Levitsky > > Maxim Levitsky (2): > kvm/x86/vmx: enable X86_FEATURE_WAITPKG in KVM capabilities > kvm/x86: don't expose MSR_IA32_UMWAIT_CONTROL unconditionally > > arch/x86/kvm/vmx/vmx.c | 3 +++ > arch/x86/kvm/x86.c | 4 ++++ > 2 files changed, 7 insertions(+) > Nit: The added 'break' statement in patch# 2 is not required. Reviewed-by: Krish Sadhukhan