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=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 28645C433E1 for ; Fri, 14 Aug 2020 10:09:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0270B2074D for ; Fri, 14 Aug 2020 10:09:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726678AbgHNKJn (ORCPT ); Fri, 14 Aug 2020 06:09:43 -0400 Received: from mga02.intel.com ([134.134.136.20]:39212 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726012AbgHNKJk (ORCPT ); Fri, 14 Aug 2020 06:09:40 -0400 IronPort-SDR: v9olPLzJFE8/D8EMOYiRzvBhLxyrqkWLDiVOc4HoyjvaYaCwpZ9V+Y+NH4RlhBbvm5TiXUaFaJ /W9bzwc20Hyg== X-IronPort-AV: E=McAfee;i="6000,8403,9712"; a="142225727" X-IronPort-AV: E=Sophos;i="5.76,311,1592895600"; d="scan'208";a="142225727" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Aug 2020 03:09:40 -0700 IronPort-SDR: Ybx8mk0552li0bdHdUB5/dPO86kL96paT7UAUsymjTxWeEEFMaHNyg4TVfG+hdQR/GllgXHLp9 0J1o/mhb1tUA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,311,1592895600"; d="scan'208";a="325687704" Received: from cqiang-mobl.ccr.corp.intel.com (HELO [10.238.2.93]) ([10.238.2.93]) by orsmga008.jf.intel.com with ESMTP; 14 Aug 2020 03:09:37 -0700 Subject: Re: [RFC 7/7] KVM: VMX: Enable PKS for nested VM To: Jim Mattson Cc: Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Joerg Roedel , Xiaoyao Li , kvm list , LKML References: <20200807084841.7112-1-chenyi.qiang@intel.com> <20200807084841.7112-8-chenyi.qiang@intel.com> <1481a482-c20b-5531-736c-de0c5d3d611c@intel.com> From: Chenyi Qiang Message-ID: Date: Fri, 14 Aug 2020 18:07:52 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/14/2020 1:52 AM, Jim Mattson wrote: > On Wed, Aug 12, 2020 at 9:54 PM Chenyi Qiang wrote: >> >> >> >> On 8/11/2020 8:05 AM, Jim Mattson wrote: >>> On Fri, Aug 7, 2020 at 1:47 AM Chenyi Qiang wrote: >>>> >>>> PKS MSR passes through guest directly. Configure the MSR to match the >>>> L0/L1 settings so that nested VM runs PKS properly. >>>> >>>> Signed-off-by: Chenyi Qiang >>>> --- > >>>> + (!vmx->nested.nested_run_pending || >>>> + !(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PKRS))) >>>> + vmcs_write64(GUEST_IA32_PKRS, vmx->nested.vmcs01_guest_pkrs); >>> >>> This doesn't seem right to me. On the target of a live migration, with >>> L2 active at the time the snapshot was taken (i.e., >>> vmx->nested.nested_run_pending=0), it looks like we're going to try to >>> overwrite the current L2 PKRS value with L1's PKRS value (except that >>> in this situation, vmx->nested.vmcs01_guest_pkrs should actually be >>> 0). Am I missing something? >>> >> >> We overwrite the L2 PKRS with L1's value when L2 doesn't support PKS. >> Because the L1's VM_ENTRY_LOAD_IA32_PKRS is off, we need to migrate L1's >> PKRS to L2. > > I'm thinking of the case where vmx->nested.nested_run_pending is > false, and we are processing a KVM_SET_NESTED_STATE ioctl, yet > VM_ENTRY_LOAD_IA32_PKRS *is* set in the vmcs12. > Oh, I miss this case. What I'm still confused here is that the restoration for GUEST_IA32_DEBUGCTL and GUEST_BNDCFGS have the same issue, right? or I miss something.