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 5C3D4C433EF for ; Tue, 15 Feb 2022 13:15:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A42206B0078; Tue, 15 Feb 2022 08:15:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9F22D6B007B; Tue, 15 Feb 2022 08:15:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8925F6B007D; Tue, 15 Feb 2022 08:15:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0143.hostedemail.com [216.40.44.143]) by kanga.kvack.org (Postfix) with ESMTP id 76AB66B0078 for ; Tue, 15 Feb 2022 08:15:18 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 2B846180AD837 for ; Tue, 15 Feb 2022 13:15:18 +0000 (UTC) X-FDA: 79145060316.25.42C1878 Received: from mail-lf1-f51.google.com (mail-lf1-f51.google.com [209.85.167.51]) by imf21.hostedemail.com (Postfix) with ESMTP id 69CFD1C0014 for ; Tue, 15 Feb 2022 13:14:31 +0000 (UTC) Received: by mail-lf1-f51.google.com with SMTP id b9so12616248lfv.7 for ; Tue, 15 Feb 2022 05:14:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=6lHSX3nDfvtiD3huNGIKRJsACSoavhTr9PgfPRk1Big=; b=ESudXjEoiYV67csMAz6wN1JL4hXkVwKkPOqRxXMFLxHapy+iAL6CtnAp5lJJKxftcc tnEuFlvih63DPCMc5rMm8JaRH/xZVy8acSSvr+UGE3IQQ501svmUL3McYgPNYlDWiNzG Tse3SmlGCSTcKPHd+PJNQYjoaLFm5XQEVVsiF5Nx2nsQqfOb8TS6CXG0S8KgWk0xkWmH 57y06dxQr31Od00TkqWsoE4vI7VaGSxiPmcouTy4BngG8hVxMt/dX4O7p0jhEkuEzuA8 WcRXRASzCPoJrQT99cPLKxNEsyWIcmdY70urf97+R+oah5HuBBpGYFe3aLxkP6kzdziV D9oQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=6lHSX3nDfvtiD3huNGIKRJsACSoavhTr9PgfPRk1Big=; b=NBM81wLXQ3HtRHEMplesH8FCFQlv+kO0+qfEup/Jo8Q9shapU1Kmhi+IgeUEv/Ba9F uLo5Qb5UTgC0/Suj4OhpMGuN3PCI57ehBTSScamERLm1KMk/yH1jqZZWfZAP2OTIGgJU WB4aYHJMESg6styZlF7Dxf/ICq363neksOtXfr9mY51+1brvYD0ukuMCu6gwX4g42Rp6 PMNQh9VzQyToYgvhjIbnlIYFoK/SnC6EgkFnkLo9F2nbCARJUKW3BmqECNlhFBXwCsHM nPYQ/rkZIJnHgPss6TkQfaOckAWJUd6D4Y/lH+shgqKS3cN0JG/jZP9q54wAHnAg687T SpwQ== X-Gm-Message-State: AOAM532qZo+pkVLpubxfalKXiVQt2AHxeDW7vsNNsoZvSgd85AgAb8Vb wqkzLtTj5R9Cdzy0mM+4QxWLmA== X-Google-Smtp-Source: ABdhPJwpX7fwVZjUgY2Y9Z1gaYIpMXSKBhynYSWG9vsJYiEN+wWS3V2I3ZjIJAY26pVz/jAP6abjnA== X-Received: by 2002:a05:6512:6c7:: with SMTP id u7mr3265230lff.128.1644930869890; Tue, 15 Feb 2022 05:14:29 -0800 (PST) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id y9sm4517142lfg.219.2022.02.15.05.14.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Feb 2022 05:14:29 -0800 (PST) Received: by box.localdomain (Postfix, from userid 1000) id DEEEF103F44; Tue, 15 Feb 2022 16:15:22 +0300 (+03) Date: Tue, 15 Feb 2022 16:15:22 +0300 From: "Kirill A. Shutemov" To: Borislav Petkov Cc: Brijesh Singh , 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, Thomas Gleixner , Ingo Molnar , Joerg Roedel , Tom Lendacky , "H. Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , 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 , Andi Kleen , "Dr . David Alan Gilbert" , brijesh.ksingh@gmail.com, tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com Subject: Re: [PATCH v10 21/45] x86/mm: Add support to validate memory when changing C-bit Message-ID: <20220215131522.l3xytgmy4ufrgnlb@box.shutemov.name> References: <20220209181039.1262882-1-brijesh.singh@amd.com> <20220209181039.1262882-22-brijesh.singh@amd.com> <0242e383-5406-7504-ff3d-cf2e8dfaf8a3@amd.com> <20220215124331.i4vgww733fv5owrx@box.shutemov.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 69CFD1C0014 X-Stat-Signature: 7pmd7c767e6euaq8ryg1oudpphjsxtex X-Rspam-User: Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=shutemov-name.20210112.gappssmtp.com header.s=20210112 header.b=ESudXjEo; spf=none (imf21.hostedemail.com: domain of kirill@shutemov.name has no SPF policy when checking 209.85.167.51) smtp.mailfrom=kirill@shutemov.name; dmarc=none X-HE-Tag: 1644930871-526211 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 Tue, Feb 15, 2022 at 01:54:48PM +0100, Borislav Petkov wrote: > On Tue, Feb 15, 2022 at 03:43:31PM +0300, Kirill A. Shutemov wrote: > > I don't think it works. TDX and SME/SEV has opposite polarity of the mask. > > SME/SEV has to clear the mask to share the page. TDX has to set it. > > > > Making a single global mask only increases confusion. > > Didn't you read the rest of the thread with Tom's suggestion? I think > there's a merit in having a cc_vendor or so which explicitly states what > type of HV the kernel runs on... I have no problem with cc_vendor idea. It looks good. Regarding the masks, if we want to have common ground here we can add two mask: cc_enc_mask and cc_dec_mask. And then pgprotval_t cc_enc(pgprotval_t protval) { protval |= cc_enc_mask; protval &= ~cc_dec_mask; return protval; } pgprotval_t cc_dec(pgprotval_t protval) { protval |= cc_dec_mask; protval &= ~cc_enc_mask; return protval; } It assumes (cc_enc_mask & cc_dec_mask) == 0. Any opinions? -- Kirill A. Shutemov