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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 6331DC4338F for ; Mon, 26 Jul 2021 18:55:30 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E6E6360F8F for ; Mon, 26 Jul 2021 18:55:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org E6E6360F8F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 37B398D0002; Mon, 26 Jul 2021 14:55:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 304018D0001; Mon, 26 Jul 2021 14:55:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1CC498D0002; Mon, 26 Jul 2021 14:55:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0031.hostedemail.com [216.40.44.31]) by kanga.kvack.org (Postfix) with ESMTP id F421F8D0001 for ; Mon, 26 Jul 2021 14:55:28 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 9BC531828D94E for ; Mon, 26 Jul 2021 18:55:28 +0000 (UTC) X-FDA: 78405642336.16.89C1CDD Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) by imf27.hostedemail.com (Postfix) with ESMTP id B8C607001F4B for ; Mon, 26 Jul 2021 18:55:27 +0000 (UTC) Received: by theia.8bytes.org (Postfix, from userid 1000) id 99991296; Mon, 26 Jul 2021 20:55:25 +0200 (CEST) Date: Mon, 26 Jul 2021 20:55:24 +0200 From: Joerg Roedel To: Marc Orr Cc: Andi Kleen , Erdem Aktas , Andy Lutomirski , Joerg Roedel , David Rientjes , Borislav Petkov , Sean Christopherson , Andrew Morton , Vlastimil Babka , "Kirill A. Shutemov" , Brijesh Singh , Tom Lendacky , Jon Grimm , Thomas Gleixner , Peter Zijlstra , Paolo Bonzini , Ingo Molnar , "Kaplan, David" , Varad Gautam , Dario Faggioli , x86 , linux-mm@kvack.org, linux-coco@lists.linux.dev Subject: Re: Runtime Memory Validation in Intel-TDX and AMD-SNP Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: Authentication-Results: imf27.hostedemail.com; dkim=none; spf=pass (imf27.hostedemail.com: domain of joro@8bytes.org designates 81.169.241.247 as permitted sender) smtp.mailfrom=joro@8bytes.org; dmarc=pass (policy=none) header.from=8bytes.org X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: B8C607001F4B X-Stat-Signature: afc53yj7cted1iko75cngwmd5fbaro1g X-HE-Tag: 1627325727-778055 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Jul 22, 2021 at 10:31:27AM -0700, Marc Orr wrote: > IMHO, we need to be completely certain that guest data cannot be > compromised if we're going to remove the requirement that guest memory > only be validated once in a certain state (e.g., from within a crash > kernel). Perhaps it is the case that we're certain that guest data > cannot be compromised from within a crash kernel -- but it's not what > I read in the email exchange. Right, at least SNP has a strict requirement that no memory could be validated or invalidated twice without giving up security guarantees for that memory. Regards, J=F6rg