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=-7.3 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 A0D38C433FE for ; Wed, 9 Dec 2020 09:10:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 60FCE23B40 for ; Wed, 9 Dec 2020 09:10:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728803AbgLIJKW (ORCPT ); Wed, 9 Dec 2020 04:10:22 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:47693 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728381AbgLIJKV (ORCPT ); Wed, 9 Dec 2020 04:10:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607504935; 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=Z8HlquEoW4X2q/+qcVSM6H75qDDj8W+Dq9wZut/Sz5s=; b=OsZ0bIonnXTORI237wlYn5X4VKEJwgHmORSbvBSSG174d1mT+/9EWRvl5E08A/Z0O5ZBJb FhjqNVTgj84j3IN+WwCdF3GGKIy3UE2v2taWRflUX5753C4Z1Gz/w9fNzjiANvTGqWL5Oi OUiyVIc+q7rS4+ToXEJl1BMelfPUP84= 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-436-TGvgQEK_NFeHOwNgjZGB0A-1; Wed, 09 Dec 2020 04:08:53 -0500 X-MC-Unique: TGvgQEK_NFeHOwNgjZGB0A-1 Received: by mail-ej1-f72.google.com with SMTP id 2so351688ejv.4 for ; Wed, 09 Dec 2020 01:08:53 -0800 (PST) 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=Z8HlquEoW4X2q/+qcVSM6H75qDDj8W+Dq9wZut/Sz5s=; b=n1NqJyezInYgvenO3dQy7dgqdP/d1SZMDKCUo+gmaKOLCK36Z9LD+JsguMpfnctm9U PQa0F+4d8d1ihrsA1n7vEoY25LbKJnGLlmk62m9jNHqxtZXdO/gKS2+fCzVXwJ74QWqB sKohJQHeHzaCXnmM4DGKU80qdFCwjOgJYx5zD8BPcC1pcGNOkPWOw//5USRcSIf6VRR3 vdVa+rA4OuqQ9LTkhYLDZn8ZVRW2xKygemOvSZwXgso5tNDDjjnaqH5WWcoRood3wzT7 ht5Vzyxk3gTecEdsyIqxaWLUx7qlomOyK+8oD0e6yKbeUGNMFJS0XKf3AVsjKu3GXF7W 62nQ== X-Gm-Message-State: AOAM531y3h1+YEmh4MLkq0CqChWGDr16F3JmAwixKVwhMXGEQ/GgtVPU 7VwHTVMH3274w46f2ejsvjaZpDmF+6m8XAoJkzS/s9yMvoryZRoABz3gt/3h+veR7iud7/RXimh u4y5h2CGX96CcSy+3yQ7CeNu8nQIwUeYoyyiqrKQpDzIWs3mn1lZFD9hAKEEcSzEonKyM+L+Zy8 Ym X-Received: by 2002:a17:906:c193:: with SMTP id g19mr1169804ejz.393.1607504932129; Wed, 09 Dec 2020 01:08:52 -0800 (PST) X-Google-Smtp-Source: ABdhPJyyCALCpD/nDA8Lmv55gbFxBTmrGaC6FbUiJ6kN1W5/lZm38nY8tddFPlonjiINu/+QS9+lYQ== X-Received: by 2002:a17:906:c193:: with SMTP id g19mr1169784ejz.393.1607504931925; Wed, 09 Dec 2020 01:08:51 -0800 (PST) Received: from [192.168.1.124] ([93.56.170.5]) by smtp.gmail.com with ESMTPSA id m24sm868412ejo.52.2020.12.09.01.08.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 09 Dec 2020 01:08:51 -0800 (PST) Subject: Re: [PATCH] KVM: mmu: Fix SPTE encoding of MMIO generation upper half To: Sean Christopherson Cc: "Maciej S. Szmigiero" , Joerg Roedel , Jim Mattson , Wanpeng Li , Vitaly Kuznetsov , Jonathan Corbet , linux-doc@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org References: <156700708db2a5296c5ed7a8b9ac71f1e9765c85.1607129096.git.maciej.szmigiero@oracle.com> <370db207-7216-ae26-0c33-dab61e0fdaab@redhat.com> From: Paolo Bonzini Message-ID: <5e1dc1cd-b175-86be-b33e-0456ecbd50e8@redhat.com> Date: Wed, 9 Dec 2020 10:08:47 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/12/20 22:12, Sean Christopherson wrote: >> #define MMIO_SPTE_GEN_MASK GENMASK_ULL(MMIO_SPTE_GEN_LOW_BITS + MMIO_SPTE_GEN_HIGH_BITS - 1, 0) > What if we leave MMIO_SPTE_GEN_MASK as is, GENMASK_ULL(17, 0), and instead add a > BUILD_BUG_ON() to assert that it matches the above logic? It's really easy to > get lost when reading through the chain of defines, I find the explicit mask > helps provide an anchor/reference for understand what's going on. It'll require > an update if/when PT64_SECOND_AVAIL_BITS_SHIFT, but that's not necessarily a bad > thing, e.g. the comment above this block will also be stale. Sounds good. Paolo