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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21F12C433EF for ; Tue, 23 Nov 2021 07:19:08 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4A2796B0071; Tue, 23 Nov 2021 02:18:52 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 42BBE6B0072; Tue, 23 Nov 2021 02:18:52 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2CBF06B0073; Tue, 23 Nov 2021 02:18:52 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0160.hostedemail.com [216.40.44.160]) by kanga.kvack.org (Postfix) with ESMTP id 19E4F6B0071 for ; Tue, 23 Nov 2021 02:18:52 -0500 (EST) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id D2D33180A6F4D for ; Tue, 23 Nov 2021 07:18:41 +0000 (UTC) X-FDA: 78839342442.06.836A779 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by imf07.hostedemail.com (Postfix) with ESMTP id A77E910002CB for ; Tue, 23 Nov 2021 07:18:30 +0000 (UTC) Received: from zn.tnic (p200300ec2f0afc00fb97e1ddac48f93a.dip0.t-ipconnect.de [IPv6:2003:ec:2f0a:fc00:fb97:e1dd:ac48:f93a]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 74C2F1EC0503; Tue, 23 Nov 2021 08:18:31 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1637651911; 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:in-reply-to:in-reply-to: references:references; bh=KqJTOgCp6HK0xHGH7GIW9dclHLRFLBvb7WQynOhv4Zo=; b=J8LWB4M2a2e8olPCNC2yFwCVo2FyCyLjyNvF0yIltKhimu2h8lvvuDckvz0d43x38j5PXn Fcci+px1bFHWiwV3UVCCecTqW5fzZ77yo4D9lYtDWn8TBi4ahZCKf/BZ6p4Jtvcn/2hdjS OxWBvL/fpLbqF+YML+r3YW6GrqG9+To= Date: Tue, 23 Nov 2021 08:18:31 +0100 From: Borislav Petkov To: Dave Hansen Cc: Brijesh Singh , Peter Gonda , x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org, linux-crypto@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Joerg Roedel , Tom Lendacky , "H. Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Andy Lutomirski , Dave Hansen , Sergio Lopez , Peter Zijlstra , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Michael Roth , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com Subject: Re: [PATCH Part2 v5 00/45] Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support Message-ID: References: <20210820155918.7518-1-brijesh.singh@amd.com> <5f3b3aab-9ec2-c489-eefd-9136874762ee@intel.com> <38282b0c-7eb5-6a91-df19-2f4cfa8549ce@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <38282b0c-7eb5-6a91-df19-2f4cfa8549ce@intel.com> X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: A77E910002CB Authentication-Results: imf07.hostedemail.com; dkim=temperror ("DNS error when getting key") header.d=alien8.de header.s=dkim header.b=J8LWB4M2; dmarc=temperror reason="query timed out" header.from=alien8.de (policy=temperror); spf=pass (imf07.hostedemail.com: domain of bp@alien8.de designates 5.9.137.197 as permitted sender) smtp.mailfrom=bp@alien8.de X-Stat-Signature: nq3dk35p6pmqm9ane5xbrazn3cfg9t38 X-HE-Tag: 1637651910-892404 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 Mon, Nov 22, 2021 at 02:51:35PM -0800, Dave Hansen wrote: > By "supporting", do you mean doing something functional? I don't really > care if ptrace() to guest private memory returns -EINVAL or whatever. > The most important thing is not crashing the host. > > Also, as Sean mentioned, this isn't really about ptrace() itself. It's > really about ensuring that no kernel or devices accesses to guest > private memory can induce bad behavior. I keep repeating this suggestion of mine that we should treat guest-private pages as hw-poisoned pages which have experienced a uncorrectable error in the past. mm already knows how to stay away from those. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette