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=-6.1 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 EAD9AC4363D for ; Wed, 30 Sep 2020 23:35:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92D552076A for ; Wed, 30 Sep 2020 23:35:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cUZ7TufY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731171AbgI3XfA (ORCPT ); Wed, 30 Sep 2020 19:35:00 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:53019 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730338AbgI3XfA (ORCPT ); Wed, 30 Sep 2020 19:35:00 -0400 Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601508898; 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=wlnOJSN7jtIyA5UuOYpzxC90dJDluDPDVDlZFnKVX1I=; b=cUZ7TufYvN3QKs01Abt3+g8NRdulpNZjryJujG+pZBQSFTQI6HceGyUSOq3jj9cBaKTejq Go/a3J7SMdXxRSTGIj52ooO4+XAfyy1km+GJl3hv4iUgHRbERl4v0XatN3m2JdZHKOiCRH uWiyx2VovtE8sZ+hGIYHyFcaMV2Jrp0= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-466-01K0kZz9N7ifeV08zx0AdA-1; Wed, 30 Sep 2020 19:34:57 -0400 X-MC-Unique: 01K0kZz9N7ifeV08zx0AdA-1 Received: by mail-wr1-f70.google.com with SMTP id v5so1236777wrs.17 for ; Wed, 30 Sep 2020 16:34:56 -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=wlnOJSN7jtIyA5UuOYpzxC90dJDluDPDVDlZFnKVX1I=; b=gCM94/LPIZUeoW5fW8s8g/JGITtdfb1DnihtK7pBgNfqR7NS7Ua7iVlPOoX3cR/mB7 Ojap1V/XlnAD5AwJiL0Z6u3EbPdPtAnhLF3KZrLepSsWBm+OQYN04+Yb3Fh9pKGorujT koTd68dORNTPtYBayRJ9YbJ0Y+qgWAxNPEpH1jb21tTqy6z9UCnY7+er4Q7nibRHh+47 04YFHVI5YyQcCl+FYjClR7DFaCD9lvcXG2LrQ7cgGh2FLwX0yTVdGsjZTWYGMvPLCwkY zszL4eN5L+/SJ4Uy5nOiML+jIo18/864HoO/6xW925MecoCm6YAJridnb/5HHYu/w79H WR4Q== X-Gm-Message-State: AOAM532keS892VYEdbmQ2kwqgaYtQQSvxiOtY7rcD+Y+7saM+mkXyfTe IxG1camPXkeqidC6maR2e61BYgaf3walN9DMBms5iMCuqHjUyPi9Jx17g/0V+OJsTw9yhJMPHm0 g1Y1vUW/gkJul X-Received: by 2002:a1c:c906:: with SMTP id f6mr5669767wmb.9.1601508895756; Wed, 30 Sep 2020 16:34:55 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxKn6uKUCblewMLqqfaHFaoCFp4t4CwvbbE55rUiCAz+ic2k4Fli2bDYK8jRAyxLTah9/YmTA== X-Received: by 2002:a1c:c906:: with SMTP id f6mr5669750wmb.9.1601508895573; Wed, 30 Sep 2020 16:34:55 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:75e3:aaa7:77d6:f4e4? ([2001:b07:6468:f312:75e3:aaa7:77d6:f4e4]) by smtp.gmail.com with ESMTPSA id f23sm1425248wmc.3.2020.09.30.16.34.54 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 30 Sep 2020 16:34:55 -0700 (PDT) Subject: Re: [PATCH 02/22] kvm: mmu: Introduce tdp_iter To: Eric van Tassell , Ben Gardon , linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Cannon Matthews , Peter Xu , Sean Christopherson , Peter Shier , Peter Feiner , Junaid Shahid , Jim Mattson , Yulei Zhang , Wanpeng Li , Vitaly Kuznetsov , Xiao Guangrong References: <20200925212302.3979661-1-bgardon@google.com> <20200925212302.3979661-3-bgardon@google.com> <4a74aafe-9613-4bf2-47a1-cad0aad34323@amd.com> From: Paolo Bonzini Message-ID: <2d43d29f-d29c-3dd7-1709-4414f34d27da@redhat.com> Date: Thu, 1 Oct 2020 01:34:53 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <4a74aafe-9613-4bf2-47a1-cad0aad34323@amd.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 01/10/20 01:20, Eric van Tassell wrote: >> >> +int is_shadow_present_pte(u64 pte) >>   { >>       return (pte != 0) && !is_mmio_spte(pte); > From
the manual I don't have at my fingertips right now, I believe you should > only check the low 3 bits(mask = 0x7). Since the upper bits are ignored, > might that not mean they're not guaranteed to be 0? No, this a property of the KVM MMU (and how it builds its PTEs) rather than the hardware present check. Paolo