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=-7.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 174E3C2B9F4 for ; Fri, 25 Jun 2021 08:57:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E3B8C61429 for ; Fri, 25 Jun 2021 08:57:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230523AbhFYJAR (ORCPT ); Fri, 25 Jun 2021 05:00:17 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:58501 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229839AbhFYJAQ (ORCPT ); Fri, 25 Jun 2021 05:00:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624611475; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Z7hC2aDaEZMwZuCypCIswjUuv9JA1ZXi3BbgeUjua2c=; b=JLWESkJ1kRXWyQdhixV4wsvckfdw5rgISRfpADGxDC5gWyNvFzOWugTkqv9SY9hyQBVEKL CKJe2eqRqMxGsHZZcm5M8o0zYs5XodsHpyb9crcaidhgguHGTpPH6NxBhyFBzZXZ9Id7NM ydWUlILCUDE4mKUK5yULM5EywMwfkzw= Received: from mail-ej1-f72.google.com (mail-ej1-f72.google.com [209.85.218.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-154-wWElaZP-O0COHkluV0XNfQ-1; Fri, 25 Jun 2021 04:57:54 -0400 X-MC-Unique: wWElaZP-O0COHkluV0XNfQ-1 Received: by mail-ej1-f72.google.com with SMTP id q14-20020a1709066aceb029049fa6bee56fso2841437ejs.21 for ; Fri, 25 Jun 2021 01:57:54 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=Z7hC2aDaEZMwZuCypCIswjUuv9JA1ZXi3BbgeUjua2c=; b=IUV0X/eD0NlFv2dPiCBEURQ2fWXwaEvNhlfX0v0iLchLVmfaL+SE78zOILp87rciq4 7qF0n52KLG0DU1q0bOcZfATmKg5bg5aMJKOouwEKGqsTcHsVSaSLWS0XvioBld7TeSYE wu/vU2+8aj8+SXlE9svb9puemLy2zxo6y5gf5u+FzIaQSlawhqQSk6dbDuw0leKg5Mmu HwqGNVXQDKqCOhMxqPGCByPs0A49OXCXpCw6nTeYta+ZkS3ftrhbZ3oOMzxOE/3M8y2d V2RbzD8B5oWsQgTFJNzwuVnXrt9aW64NtpbVCDXPNrmphb3jRNI7gZLHpgbto0AvYpqV +9HA== X-Gm-Message-State: AOAM530XGEGNrgrFVNVP0a9Pj/QKjpD/RlL4z1+EO4flrIlAfbb/aBsm rUYgzGeSmSz0H6Jgi/W76NiK6SEB9YfXU3b6P7dvZtZ8tkxfKF0mJULLuPNb4yAbzyBXfhM4m9g RP12wytzw/meY X-Received: by 2002:aa7:c648:: with SMTP id z8mr1097312edr.384.1624611473118; Fri, 25 Jun 2021 01:57:53 -0700 (PDT) X-Google-Smtp-Source: ABdhPJysSqfGdK5bBctBEQT5D4lGEIgTGtqG/WbIFUmNaQcm+60RoRS+vvF3iacOwH1FhxuIliPxYA== X-Received: by 2002:aa7:c648:: with SMTP id z8mr1097302edr.384.1624611473014; Fri, 25 Jun 2021 01:57:53 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.gmail.com with ESMTPSA id qq26sm2408826ejb.6.2021.06.25.01.57.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 25 Jun 2021 01:57:52 -0700 (PDT) Subject: Re: [PATCH 05/54] Revert "KVM: x86/mmu: Drop kvm_mmu_extended_role.cr4_la57 hack" To: Yu Zhang , Sean Christopherson Cc: Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Maxim Levitsky References: <20210622175739.3610207-1-seanjc@google.com> <20210622175739.3610207-6-seanjc@google.com> <20210625084644.ort4oojvd27oy4ca@linux.intel.com> From: Paolo Bonzini Message-ID: <09a49caf-6ff5-295b-d1ab-023549f6a23b@redhat.com> Date: Fri, 25 Jun 2021 10:57:51 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <20210625084644.ort4oojvd27oy4ca@linux.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 25/06/21 10:47, Yu Zhang wrote: >> But if L1 is crafty, it can load a new CR4 on VM-Exit and toggle LA57 >> without having to bounce through an unpaged section. L1 can also load a > > May I ask how this is done by the guest? Thanks! It can set HOST_CR3 and HOST_CR4 to a value that is different from the one on vmentry. Paolo