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=-6.6 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 3F03EC4363D for ; Wed, 23 Sep 2020 15:19:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECA8421D43 for ; Wed, 23 Sep 2020 15:19:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="M+OmTQ0j" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726721AbgIWPTx (ORCPT ); Wed, 23 Sep 2020 11:19:53 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:32802 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726265AbgIWPTx (ORCPT ); Wed, 23 Sep 2020 11:19:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600874392; 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=VP/uPxlVn+VO8OSs/cXXYD6CRLQQniKKhgRTFTtzIRU=; b=M+OmTQ0jCuGVjTUAXx2Tn0oAXoNEeuHUi87msS1s75acSwtd0PgkS9Y99XXtbps6uRnGyl OQSKZhFTHI/dTvHYsdqavag74Lm6igWo3vmwW/ryOvXX7RZ8yDRvOah1oc9IEYN+o01Nl1 kzbnYG5VnrraThBMAUfk2zfgIHh0hnk= 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-141-1xsYwNAbPrS5sBBfeI8p9w-1; Wed, 23 Sep 2020 11:19:50 -0400 X-MC-Unique: 1xsYwNAbPrS5sBBfeI8p9w-1 Received: by mail-wr1-f70.google.com with SMTP id l9so8916037wrq.20 for ; Wed, 23 Sep 2020 08:19:49 -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=VP/uPxlVn+VO8OSs/cXXYD6CRLQQniKKhgRTFTtzIRU=; b=q+nt+LgFOZHDPef0pEbgTB5RecAL9PNr6OFBu6C5OlFPTStTKs1ZX8iKfV4TOEiiGp VQGhTnRAVJtMgyqCB/C1aw51AenmflGwSsvZTHzuPPupQoGRW44NJYeCqS3HmbqsDRei 7H2BHdVyQNMUphK6J5T3NFuLUk6MdQQ1PeELdX8QKFIp4K8YBryd0A5/2Qrw9WIX91Pj VNscigeZHOGjbZzOWBHSsxCY9/ssOBCFGRGqNjls+tLNbLpPNnf+Y+YlLlbtLZ+zYx5c WbFHTQKzIqY+KaV7t2QJ0zUeEA3F3QCKEoXIEPUoy5qkLRYyNYfrwqSBRG6i+jmQ0B45 MLrQ== X-Gm-Message-State: AOAM531Z52rFGGp28Q0GPLQ8j7i3I6fKMiamun9uo0RpQytj6GOhpLrc oySh034m9sH3lk7tG1TKyFCPGkmqK7a8nrzM6/syod3hhGW4VG0hX1vG4asxPcu9tAlxwAwQwLT 7N4eD3QzrquZlrovEbgLyHgYO X-Received: by 2002:a05:600c:22d2:: with SMTP id 18mr25121wmg.145.1600874389035; Wed, 23 Sep 2020 08:19:49 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzbgMoWwfq+neyAnsK0EaJ4ibs2pkKiG4LrxWCZ5IbM3u5TcuDmjgY1SOIQ3UTsK1K+EpMxkg== X-Received: by 2002:a05:600c:22d2:: with SMTP id 18mr25098wmg.145.1600874388795; Wed, 23 Sep 2020 08:19:48 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:15f1:648d:7de6:bad9? ([2001:b07:6468:f312:15f1:648d:7de6:bad9]) by smtp.gmail.com with ESMTPSA id c4sm120226wme.27.2020.09.23.08.19.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 23 Sep 2020 08:19:48 -0700 (PDT) Subject: Re: [PATCH] KVM: x86: VMX: Make smaller physical guest address space support user-configurable To: Jim Mattson Cc: Mohammed Gamal , joro@8bytes.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, sean.j.christopherson@intel.com, vkuznets@redhat.com, wanpengli@tencent.com References: <20200903141122.72908-1-mgamal@redhat.com> <8c7ce8ff-a212-a974-3829-c45eb5335651@redhat.com> From: Paolo Bonzini Message-ID: <79277092-a5b8-ebb0-8a9f-e41d094ed05b@redhat.com> Date: Wed, 23 Sep 2020 17:19:46 +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: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 23/09/20 16:32, Jim Mattson wrote: > You don’t buy my argument that this should be per-VM, then? I’d bet that > we have very close to 0 customers who care about emulating the reserved > bits properly for 46-but wide VMs, but there may be someone out there > using shadow paging in a nested kvm.  > I do buy it but I prefer not to have a released version of Linux where this is enabled by default. I procrastinated hoping to cobble something together but I didn't have time. Paolo