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 6530FC433FE for ; Fri, 29 Apr 2022 14:42:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377679AbiD2Ops (ORCPT ); Fri, 29 Apr 2022 10:45:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52502 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377654AbiD2Opo (ORCPT ); Fri, 29 Apr 2022 10:45:44 -0400 Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F1D9968300 for ; Fri, 29 Apr 2022 07:42:25 -0700 (PDT) Received: by mail-pf1-x42d.google.com with SMTP id y38so7091569pfa.6 for ; Fri, 29 Apr 2022 07:42:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Q8Sf/GbjZKXQvTHW2LwW4qAGOz3b9F7JEp6h77YJ1Oo=; b=qkeV4CtdSEM5tiWHb1MIxWYVlPfLgGE7UevmkBnAbFH9057fEACF93fsFXKz4W78kT GolFOevTDcjA6d9cOVyV8wm7NnCDZpJ6qMGTbgJLEXqq7xa/3ulb+5ZzBKpxqGlXSq6d HdtRm0U0qlohOxBJOOLjb0QyzAAA1vC+e25Kdwxz+tYDp/PmNt/RK28EeG0VakCxkJJK tIn2Dj9i9H7HBZiiN7/80Ce64afhJkaLQ5tq338mVjJ18i/IyRjej+Bl2QfkoUPXP+lJ onZ+lHU0vcjwafKhTaKJtkxRFdBtVZeG362TZVEFKS87HvQrmMzWvPKqEKkT8HPhRqVV aosA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Q8Sf/GbjZKXQvTHW2LwW4qAGOz3b9F7JEp6h77YJ1Oo=; b=TP6jKW2mXeQCUO283Tjh8wS0vCJBC1mi6GMl4uQSjURKzWzQle6fkiQHjLqJwo6vYb wBqB2oWUotirNzRXERVBB4A94wS+7K0cvVXaaVwtJ55i9+F9ub5YdL+k1OwEn7TrGoup STZLpygkzEGrWV8XQx1MrM4cLxilSrlEj8OAtIXSdpKqi87dPDikeHz+JNetJdNTNbU0 WwEyrc6WkuPVg4ZTBlpNBzbku23obw1AaFNeWGY6KussszRAlXJ8v9Wiv2Fzzu/ddUhH BbqxijGkfpBsFiuL+K+1no0rkWGos/H2hJ1OFwUZdg/nD35Lt3X7m7GM8npuOghJ5WBE xJWQ== X-Gm-Message-State: AOAM531dFbxLXX3j7QGmVN9E4kOO3paJvlHFzpaAe46jGEveOkVtYM6J 6hrcMRrht8lwo9djsMp5xD6jo3EItxGw0Q== X-Google-Smtp-Source: ABdhPJzTZJpSp9OxdNz1eGasYYqmBNDjW6EMNn24fFlY6RotVQJetGMsjQZrSR30PRSCZy5b5WZcYA== X-Received: by 2002:a63:d758:0:b0:380:fba9:f6e5 with SMTP id w24-20020a63d758000000b00380fba9f6e5mr32765775pgi.330.1651243345281; Fri, 29 Apr 2022 07:42:25 -0700 (PDT) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id n2-20020aa79042000000b005057336554bsm3382348pfo.128.2022.04.29.07.42.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 29 Apr 2022 07:42:24 -0700 (PDT) Date: Fri, 29 Apr 2022 14:42:21 +0000 From: Sean Christopherson To: Paolo Bonzini Cc: Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Maxim Levitsky , Ben Gardon , David Matlack Subject: Re: [PATCH] KVM: x86/mmu: Do not create SPTEs for GFNs that exceed host.MAXPHYADDR Message-ID: References: <20220428233416.2446833-1-seanjc@google.com> <337332ca-835c-087c-c99b-92c35ea8dcd3@redhat.com> <20e1e7b1-ece7-e9e7-9085-999f7a916ac2@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20e1e7b1-ece7-e9e7-9085-999f7a916ac2@redhat.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Apr 29, 2022, Paolo Bonzini wrote: > On 4/29/22 16:24, Sean Christopherson wrote: > > I don't love the divergent memslot behavior, but it's technically correct, so I > > can't really argue. Do we want to "officially" document the memslot behavior? > > > > I don't know what you mean by officially document, Something in kvm/api.rst under KVM_SET_USER_MEMORY_REGION. > but at least I have relied on it to test KVM's MAXPHYADDR=52 cases before > such hardware existed. :) Ah, that's a very good reason to support this for shadow paging. Maybe throw something about testing in the changelog? Without considering the testing angle, it looks like KVM supports max=52 for !TDP just because it can, because practically speaking there's unlikely to be a use case for exposing that much memory to a guest when using shadow paging.