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 5D3D6C433FE for ; Tue, 23 Nov 2021 07:18:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233900AbhKWHVm (ORCPT ); Tue, 23 Nov 2021 02:21:42 -0500 Received: from mail.skyhub.de ([5.9.137.197]:47558 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233677AbhKWHVk (ORCPT ); Tue, 23 Nov 2021 02:21:40 -0500 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> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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