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 D7123C48BC2 for ; Wed, 23 Jun 2021 14:01:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB80E6108E for ; Wed, 23 Jun 2021 14:01:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231252AbhFWODw (ORCPT ); Wed, 23 Jun 2021 10:03:52 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:56731 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230312AbhFWODv (ORCPT ); Wed, 23 Jun 2021 10:03:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624456893; 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=GI7BUvQGaSJTYs1XHkSa35D9gwv1cTj0EBhXSBIFL1M=; b=S1o6A23ECx4vq9DQGGQIOlNVBm08Y2mS+YNEnnH6LeJfkiyRmGqO0ZPtrAYuXOc840GDYd DklbtNMjI/+AR+s8tFAVspMAFUx6x6hcEVanSxTTenvxYDjLcCXmkg+sVfhXepsQ8+uBA8 cJ6etpy6WYVJNpLiC5JW4tpDiTKfrOc= Received: from mail-ej1-f69.google.com (mail-ej1-f69.google.com [209.85.218.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-522-xZkN8XtAO_yDNv0FmAPdvQ-1; Wed, 23 Jun 2021 10:01:31 -0400 X-MC-Unique: xZkN8XtAO_yDNv0FmAPdvQ-1 Received: by mail-ej1-f69.google.com with SMTP id o12-20020a17090611ccb02904876d1b5532so1019497eja.11 for ; Wed, 23 Jun 2021 07:01:31 -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=GI7BUvQGaSJTYs1XHkSa35D9gwv1cTj0EBhXSBIFL1M=; b=ByUFnflru4soufCvAB9xCi1BcsXqMB1lAPqF3iKyEqfa+SiDWLclVYdrb2y3KZ0Js+ bAy4pGJj0nSGs7iaAEANBzkQVzsWAKLcym7m2Fe04Ojv95i65dgOhx1CIFyPYi4Cp8Co 3wMJKcHWt2/9z7AAgoiSYM1OhYeWveAki3QcCiXRHG16sJyBtBDp+ovsCd6CXQzX6uvJ QoKWW0i1SULjXcv+/VMS0LJEFGzyWTJP7Y3lXcxtlmoWKUFF4LLHEw1Yyu+S6fD1i4Um a338CrITttOpwL/Cnl0FOJ9Y0JVFRWj8m5i7Gn/sMnNZJpQLH4SNkoEtf6P5AeT5RutT 1Fmw== X-Gm-Message-State: AOAM533ykCDR13alUJDAKH6eZ9DgsoieJLvNw5t9mHH6zAnnr8FRH9KH 4jSSF5X4BZnwCDC6gq7KlPF0+NBtb6K02EDe7QT7+PSPgowj9IvMPY1D11g/f9azJ6vnhXTriHr 9io0XIL2zs4bkXMIdN2cYCGsd X-Received: by 2002:a17:906:36d5:: with SMTP id b21mr181071ejc.258.1624456890705; Wed, 23 Jun 2021 07:01:30 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxVVzhqdfVDJJTFG6BriT0PEnR8sAnb90HHFIoMhWugO9e/5JQG8bPfqCAHNolqC3qdIS/oPg== X-Received: by 2002:a17:906:36d5:: with SMTP id b21mr181048ejc.258.1624456890517; Wed, 23 Jun 2021 07:01:30 -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 u12sm7382464eje.40.2021.06.23.07.01.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 23 Jun 2021 07:01:29 -0700 (PDT) Subject: Re: [PATCH 03/54] KVM: x86: Properly reset MMU context at vCPU RESET/INIT To: Sean Christopherson Cc: Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Yu Zhang , Maxim Levitsky References: <20210622175739.3610207-1-seanjc@google.com> <20210622175739.3610207-4-seanjc@google.com> From: Paolo Bonzini Message-ID: <3c3f9251-cab4-70ee-6e38-85fe8e6579f7@redhat.com> Date: Wed, 23 Jun 2021 16:01:28 +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: <20210622175739.3610207-4-seanjc@google.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: linux-kernel@vger.kernel.org On 22/06/21 19:56, Sean Christopherson wrote: > + /* > + * Reset the MMU context if paging was enabled prior to INIT (which is > + * implied if CR0.PG=1 as CR0 will be '0' prior to RESET). Unlike the > + * standard CR0/CR4/EFER modification paths, only CR0.PG needs to be > + * checked because it is unconditionally cleared on INIT and all other > + * paging related bits are ignored if paging is disabled, i.e. CR0.WP, > + * CR4, and EFER changes are all irrelevant if CR0.PG was '0'. > + */ > + if (old_cr0 & X86_CR0_PG) > + kvm_mmu_reset_context(vcpu); Hmm, I'll answer myself, is it because of the plan to add a vCPU reset ioctl? Paolo