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=-8.0 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 118A9C433B4 for ; Tue, 4 May 2021 20:26:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D73B861059 for ; Tue, 4 May 2021 20:26:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232596AbhEDU1X (ORCPT ); Tue, 4 May 2021 16:27:23 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:29803 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229542AbhEDU1W (ORCPT ); Tue, 4 May 2021 16:27:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620159986; 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=NmaFtxsE0S5qvJK+FcOeAQOG1JYRVA5bDwB/1VM2dIk=; b=QqAvEi4FNbgdlCddsw6m88UPDAxj6Wrpsxgo8CdKS2PsdAFhGMPonsRL6pzhmfQzS+4ubj pkF15OpCS2HZft+N4hWlGSqWqCqwuuLI32Lczews0Yoae222RxY4GKyGEYtMHkvYmDUlb7 hA7zvrYaKAXMXb1t4BEE8FlQp6MG7Zg= Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-226-ZogSY5DJPc2kNS68Ssw1_Q-1; Tue, 04 May 2021 16:26:24 -0400 X-MC-Unique: ZogSY5DJPc2kNS68Ssw1_Q-1 Received: by mail-ed1-f72.google.com with SMTP id g7-20020aa7c5870000b02903888f809d62so6056639edq.23 for ; Tue, 04 May 2021 13:26:24 -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=NmaFtxsE0S5qvJK+FcOeAQOG1JYRVA5bDwB/1VM2dIk=; b=AnGxo+qSM86zoKHGZZhUh81YeUdnbZ/MLyZclji7PLgjnMUXzYlOzWfbt8bR+RucDY zUM0QsKhg3AcANedBqguOnSMV96Rvm59FcgAWs1rJavauTcQrG7mJmcqsSOwJRa8YVRT S6uRfcAvGCe52A9t15iDYxym1KEXw+ccjzwLPn5n1WeLIHDGQLe44qlWJ02B1ZyUXEKZ 8sw23nNSXrLNEbeajRQ6MHWI2R2i6WXQHb0iQ4g44E3+3r1w+5mc0FBe4f9iFUYZz998 X2VDObPGvGYr//rnwEUXOryki+n2TmqAaxOZsbhS9gOdxrpvCumb6TfpSjfW0nvvCdA2 p+Dw== X-Gm-Message-State: AOAM530gkWn6p5pzs9hLxs6O5lTfCAAmK+tsyvUNnvvcDT/OHlAmrWbZ c2Q9/XZUYSI4S/Vmqmhhcit0XYS5TqduhtjM1oeMTavq6gdp/Fex1LCY51zQ087mZN6UpSDC9Yq +f/SWT1A1R5au X-Received: by 2002:a17:906:fcd6:: with SMTP id qx22mr24014615ejb.529.1620159983342; Tue, 04 May 2021 13:26:23 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxh1zbFHg9vwi2oHIGX5YBErFcyt0Oodg4Od0An9+HOszlBG2A+myYeCIIk2cSbkE0RAwV6gQ== X-Received: by 2002:a17:906:fcd6:: with SMTP id qx22mr24014595ejb.529.1620159983133; Tue, 04 May 2021 13:26:23 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:5e2c:eb9a:a8b6:fd3e? ([2001:b07:6468:f312:5e2c:eb9a:a8b6:fd3e]) by smtp.gmail.com with ESMTPSA id ca20sm1907157ejb.84.2021.05.04.13.26.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 04 May 2021 13:26:22 -0700 (PDT) Subject: Re: [PATCH v2 1/7] KVM: x86/mmu: Track if shadow MMU active To: Sean Christopherson , Ben Gardon Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Peter Xu , Peter Shier , Junaid Shahid , Jim Mattson , Yulei Zhang , Wanpeng Li , Vitaly Kuznetsov , Xiao Guangrong References: <20210429211833.3361994-1-bgardon@google.com> <20210429211833.3361994-2-bgardon@google.com> From: Paolo Bonzini Message-ID: Date: Tue, 4 May 2021 22:26:18 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: 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 04/05/21 21:55, Sean Christopherson wrote: > But, I think we we can avoid bikeshedding by simply eliminating this flag. More > in later patches. Are you thinking of checking slot->arch.rmap[0] directly? That should work indeed. >> - kvm_mmu_init_tdp_mmu(kvm); >> + if (!kvm_mmu_init_tdp_mmu(kvm)) >> + activate_shadow_mmu(kvm); > Doesn't come into play yet, but I would strongly prefer to open code setting the > necessary flag instead of relying on the helper to never fail. > You mean kvm->arch.shadow_mmu_active = !kvm_mmu_init_tdp_mmu(kvm); (which would assign to alloc_memslot_rmaps instead if shadow_mmu_active is removed)? That makes sense. Paolo