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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A7EFC35274 for ; Mon, 7 Feb 2022 14:21:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1391202AbiBGOT1 (ORCPT ); Mon, 7 Feb 2022 09:19:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43744 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1389029AbiBGNvD (ORCPT ); Mon, 7 Feb 2022 08:51:03 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 7CA92C0401C0 for ; Mon, 7 Feb 2022 05:51:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1644241861; 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=msKQIf5m3RNJ8ndoRLO0bGCg3f8WFhwpKNN7KVs8sjk=; b=H/BBLsEau9tMutIpd1EYmv++jkFa+p+tgr3Z45IWnJfLf25I0xbVtge+GiGUrXmM2LFBOZ kFwNwgubg5up33J6nEuJB+PC0EF3+QnjrsFIgL/J8pKRf1C0IvLDWoXxDEyZv5rx1+R7C5 eFcaNzecQCap7jwm5Q+eWGXnuNEvzMU= Received: from mail-ej1-f71.google.com (mail-ej1-f71.google.com [209.85.218.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-611-y9qTajqZOvKmpr-7Y9xD7A-1; Mon, 07 Feb 2022 08:51:00 -0500 X-MC-Unique: y9qTajqZOvKmpr-7Y9xD7A-1 Received: by mail-ej1-f71.google.com with SMTP id o7-20020a170906860700b006cbe6deec1bso649761ejx.22 for ; Mon, 07 Feb 2022 05:51:00 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=msKQIf5m3RNJ8ndoRLO0bGCg3f8WFhwpKNN7KVs8sjk=; b=yLjjsnhYwBwOZ+RFThPdcQl+nMQHsnUVx0EMNS8vyyOGI8K7bhybUQI+TrudmC/GMu 8SCkMpnSI93YdT/pf2S9Gn4DOYNXB1ndhVZGYv/QwKdP8cudrB4jUtOXQv1RabmPRCXD J3BYaJQkGFMI6hirSSoMiRMI1CQqPQn1N0R4gAWK/D0tCmAPyXak92pr7LKk+5W6DiKd ONQ2ooPnYMn4D0H/066uz+5U5m3nOMKyRXtwMlxOwdrzqtMitnLNQrqDbJlhPRbiVQZn eg8rUxkzry0Mtwx8c4Y/5fhTACWR4tGeJCZ6KJGb1Ylv5nQvwfr1eay1xt+kyueliZWq 5c2g== X-Gm-Message-State: AOAM533CiUMRSZWAZPh2wCQBx0HJM0X4HYLk4egH5RzLLqV2Et5rXyED KehN+ef74EZ0FXigRCg9ymIeay371YdNxMImYwActM5SKfrV4i4jBYwLpoPvZHKhv4a0yS2Pc4y wnqoVq1KR5PyXA/ndruHVLC1m X-Received: by 2002:a17:907:e9e:: with SMTP id ho30mr9943362ejc.648.1644241859351; Mon, 07 Feb 2022 05:50:59 -0800 (PST) X-Google-Smtp-Source: ABdhPJyy7q7L46GUgvrZDsUs7fcdkR+jHAnTyhwBqS2NTRUYS3qbGsv1f/ky1Xjl5fOHHMMPa2/MXg== X-Received: by 2002:a17:907:e9e:: with SMTP id ho30mr9943343ejc.648.1644241859035; Mon, 07 Feb 2022 05:50:59 -0800 (PST) Received: from ?IPV6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.googlemail.com with ESMTPSA id qh12sm225724ejb.172.2022.02.07.05.50.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 07 Feb 2022 05:50:58 -0800 (PST) Message-ID: <180d7f0f-8c58-2a52-02a7-bd014d81d7a3@redhat.com> Date: Mon, 7 Feb 2022 14:50:57 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH 06/23] KVM: MMU: load new PGD once nested two-dimensional paging is initialized Content-Language: en-US To: David Matlack Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, seanjc@google.com, vkuznets@redhat.com References: <20220204115718.14934-1-pbonzini@redhat.com> <20220204115718.14934-7-pbonzini@redhat.com> From: Paolo Bonzini In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/4/22 20:18, David Matlack wrote: > On Fri, Feb 04, 2022 at 06:57:01AM -0500, Paolo Bonzini wrote: >> __kvm_mmu_new_pgd looks at the MMU's root_level and shadow_root_level >> via fast_pgd_switch. > Those checks are just for performance correct (to skip iterating through > the list of roots)? > > Either way, it's probably worth including a Fixes tag below. > There's no bug because __kvm_mmu_new_pgd is passed a correct new_role. But it's unnecessarily complex as shown by patches 7 and 9. Paolo