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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 1AC32C432BE for ; Tue, 17 Aug 2021 20:44:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 04CA66103A for ; Tue, 17 Aug 2021 20:44:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234461AbhHQUou (ORCPT ); Tue, 17 Aug 2021 16:44:50 -0400 Received: from mail.skyhub.de ([5.9.137.197]:39396 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229847AbhHQUos (ORCPT ); Tue, 17 Aug 2021 16:44:48 -0400 Received: from zn.tnic (p200300ec2f117500b0ae8110978caeec.dip0.t-ipconnect.de [IPv6:2003:ec:2f11:7500:b0ae:8110:978c:aeec]) (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 72BF51EC054F; Tue, 17 Aug 2021 22:44:08 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1629233048; 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=kGYRnAMSLbjZ/FPl31T/5mLxunyqniOXuhCt9CoiNRU=; b=idhoqaoyNMw69THb+H9A2bvcCKeTLrJJEVDaSQEOLre37KzokOn5QvSNWIaUINNWyKXzfL zFyPuHjYKuUCSBTfF15vmrp6mLt5UlEQXw1zBkbpwbbgFtKjzb2XpHf60liU/yGOXA4AeB oQBWI2rcyv8ZFE0Nkd6kyFS0kkGo3J4= Date: Tue, 17 Aug 2021 22:44:48 +0200 From: Borislav Petkov To: Brijesh Singh Cc: x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-efi@vger.kernel.org, platform-driver-x86@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 Gonda , Peter Zijlstra , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Michael Roth , Vlastimil Babka , tony.luck@intel.com, npmccallum@redhat.com, brijesh.ksingh@gmail.com Subject: Re: [PATCH Part1 RFC v4 15/36] x86/mm: Add support to validate memory when changing C-bit Message-ID: References: <20210707181506.30489-1-brijesh.singh@amd.com> <20210707181506.30489-16-brijesh.singh@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Aug 17, 2021 at 03:34:41PM -0500, Brijesh Singh wrote: > I am not seeing any strong reason to sanity check the reserved bit in the > psc_entry. The fields in the psc_entry are input from guest to the > hypervisor. The hypervisor cannot trick a guest by changing anything in the > psc_entry because guest does not read the hypervisor filled value. I am okay > with the psc_hdr because we need to read the current and end entry after the > PSC completes to determine whether it was successful and sanity checking PSC > header makes much more sense. Let me know if you are okay with it ? Ok, fair enough. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette