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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 1D72AC4332B for ; Wed, 27 Jan 2021 04:24:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA0DF20719 for ; Wed, 27 Jan 2021 04:24:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238478AbhA0EYC (ORCPT ); Tue, 26 Jan 2021 23:24:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59554 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390069AbhA0AOj (ORCPT ); Tue, 26 Jan 2021 19:14:39 -0500 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B6EBC061788 for ; Tue, 26 Jan 2021 16:13:56 -0800 (PST) Received: by mail-pf1-x435.google.com with SMTP id m6so48799pfk.1 for ; Tue, 26 Jan 2021 16:13:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Eg1+IXQ+KG25hfpLfWECGEtHCa9ZmmkTs6X5ipIqXso=; b=A3+wyR7Tw2RVfQ5N8CwLN9nmb2NGSUCXSUCy16AfW2YHvHVpbMca9k7+Uqg6BydcUP CD8uyf6CKxoeIIpz9A3BcpPdPpJtVaosFsS7U0+SLb6+V9bH1jH/dBrH5Z0Ue41dGrUH 5kY6RcLOjt0LlXl2Yew8J1x4Tf6aUy+yfb+yGSJ+yw7OX5K2e0UkIzcp1vPwQsOwjMYG qnzl4kORkTc51FIIR5EP0Pwz5it0Xgdi43WiS8Pc55RIw4FKim1ZMw8bl0bXbBmgf6b2 f/6SSEpJZbpEIMcA2LA6EBijbjGtXSGZBdkq1fN6oZbmQdhpMgS3sgzBCbBFIH/x1Ke5 G1Yw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Eg1+IXQ+KG25hfpLfWECGEtHCa9ZmmkTs6X5ipIqXso=; b=EcvDZCsrAAUxVnPZS7pXen5NlpObkPPp8l++ONPjSt6ozrsz4pJLVOZ3H+QddH1mgH f5YMFgZAOD85y/CXwN8QowDGuz8mN6nXDFaKetzL7j3NhAa4KpozbrV/griwrP+gUGVw YoEvGtcbQa0G4Mk9j0GoqvwhW1rBYgKlVQrU/Y1sq9ac8k70xl/LjIXI+UT2hsnj8zox xB/zA75oKGuzGCda6CbKt1MZt9Tps2ZudrCfKoLuoUUd/hzJyJG9Ae+yQDoaISE+bjXN QTbpuVs3ohOGOgmqI5hHDQPAyPyk+gwdbd9YfKbCmlhb91MbLUlBTkND3IIgVyQPCvqs kp0A== X-Gm-Message-State: AOAM530RqqZppYxPwPUj4cKQ0zHHgln3AJ7WL18jForwLW2ZMuyUeXBP D3hBC5gXCND2aongxmDAyGAiAQ== X-Google-Smtp-Source: ABdhPJwi/cjpRNck5xySzt/sdXxpPflSZCwPr7heWqTtNlCahUQS3RnLmA1I2IW5y20J/WIYUexGKg== X-Received: by 2002:a62:1a50:0:b029:1c5:112a:f42f with SMTP id a77-20020a621a500000b02901c5112af42fmr4242651pfa.77.1611706435561; Tue, 26 Jan 2021 16:13:55 -0800 (PST) Received: from google.com ([2620:15c:f:10:1ea0:b8ff:fe73:50f5]) by smtp.gmail.com with ESMTPSA id 21sm209985pfu.136.2021.01.26.16.13.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Jan 2021 16:13:54 -0800 (PST) Date: Tue, 26 Jan 2021 16:13:48 -0800 From: Sean Christopherson To: Babu Moger Cc: pbonzini@redhat.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, fenghua.yu@intel.com, tony.luck@intel.com, wanpengli@tencent.com, kvm@vger.kernel.org, thomas.lendacky@amd.com, peterz@infradead.org, joro@8bytes.org, x86@kernel.org, kyung.min.park@intel.com, linux-kernel@vger.kernel.org, krish.sadhukhan@oracle.com, hpa@zytor.com, mgross@linux.intel.com, vkuznets@redhat.com, kim.phillips@amd.com, wei.huang2@amd.com, jmattson@google.com Subject: Re: [PATCH v3 2/2] KVM: SVM: Add support for Virtual SPEC_CTRL Message-ID: References: <161073115461.13848.18035972823733547803.stgit@bmoger-ubuntu> <161073130040.13848.4508590528993822806.stgit@bmoger-ubuntu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Jan 20, 2021, Babu Moger wrote: > > On 1/19/21 5:45 PM, Sean Christopherson wrote: > > Potentially harebrained alternative... > > > > From an architectural SVM perspective, what are the rules for VMCB fields that > > don't exist (on the current hardware)? E.g. are they reserved MBZ? If not, > > does the SVM architecture guarantee that reserved fields will not be modified? > > I couldn't (quickly) find anything in the APM that explicitly states what > > happens with defined-but-not-existent fields. > > I checked with our hardware design team about this. They dont want > software to make any assumptions about these fields. Drat, I should have begged for forgiveness instead of asking for permission :-D