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=-8.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=unavailable 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 8610EC31E57 for ; Mon, 17 Jun 2019 11:25:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 540672084A for ; Mon, 17 Jun 2019 11:25:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=shutemov-name.20150623.gappssmtp.com header.i=@shutemov-name.20150623.gappssmtp.com header.b="uV36HBJj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728294AbfFQLZH (ORCPT ); Mon, 17 Jun 2019 07:25:07 -0400 Received: from mail-ed1-f66.google.com ([209.85.208.66]:33070 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728234AbfFQLZD (ORCPT ); Mon, 17 Jun 2019 07:25:03 -0400 Received: by mail-ed1-f66.google.com with SMTP id i11so15693091edq.0 for ; Mon, 17 Jun 2019 04:25:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=9AwinP98tyRtHdg0mJkLa6bfVqgtL4TsktjuNz76Who=; b=uV36HBJjLuM8IaSJ5lnIjDPz/NT6Ima0VTqA5XgxtXzYGLtD5Zk1oOFcZIOs5eNXNV pH0NKGr3K5PIEFLdfJ4QY5MASu8ZolMiISb4+T5+hLkqTyBzPrnUDdx/hU3vjrgigEg5 XFnoHWLNGGyz/u66QlR4uui8QiQ+svYc42qDT7NRAQYv6KgqnNwvy4xSWlxjmoYgo9KT ekxQsjh1gx+i56hFixjDbLIdHmzETZGZXB2016IB59YaBabg47ntq/77FeVXdTQW9Mw5 aQMao99SPvxYN97xvhncTxzUgIhypTKI32Gazqeb0JGoQgELhGOXdv5DquuY1RhnraGV TZKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=9AwinP98tyRtHdg0mJkLa6bfVqgtL4TsktjuNz76Who=; b=Hh0fXHvyyGlOL+yx6gorU0u74+e14eE4dRPlhYmNR0jNdJClC1OppF0Y1tPU3G2VJX gnBvf6QAYBNWlK9A2PFb6WPnqReQ/CBPFdCQu4j3XOxIx8Mbln+5nncEjIjJPyrYbqWh cEdZBV3BnJw09jSVOBJ8qo0ETDO7nLG4pMs/Q4U65NLG5T1/TMkGuj1o2O0Zg3PmZ0Q7 Cy7t6qUrvDcGpwCsygPEfjpW7rM3Vc4vsx5IL8wviw4bPQG9xm2n9q3f0mJCiiqJccHd 4e5loqv1V/rS3XOUHwMB203QcbBfMf7PFejNMeTsImUnxBlpbeXgGW9VrMhUtl6Dm1PD Alhg== X-Gm-Message-State: APjAAAXX5+gme083LugaOUybEH/NZZ86ui+Z0h1hWwEGl7RJ/qSdy7ev Zo8svikA1s9lg6Y/9B9rjRMY7g== X-Google-Smtp-Source: APXvYqwcK64TzeBKKN7Kf5JNSHie2auwQpGxruSpvU1WBTnyHll+7eGrNwcSGlsUpIC9SxKCjImLYg== X-Received: by 2002:a50:a48a:: with SMTP id w10mr11385422edb.1.1560770702235; Mon, 17 Jun 2019 04:25:02 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id w35sm1152436edd.32.2019.06.17.04.25.00 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 17 Jun 2019 04:25:01 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id 122F1100F6D; Mon, 17 Jun 2019 14:25:00 +0300 (+03) Date: Mon, 17 Jun 2019 14:25:00 +0300 From: "Kirill A. Shutemov" To: Kai Huang Cc: Peter Zijlstra , "Kirill A. Shutemov" , Andrew Morton , x86@kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Borislav Petkov , Andy Lutomirski , David Howells , Kees Cook , Dave Hansen , Jacob Pan , Alison Schofield , linux-mm@kvack.org, kvm@vger.kernel.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH, RFC 49/62] mm, x86: export several MKTME variables Message-ID: <20190617112500.vmuu4kcjoep34hwe@box> References: <20190508144422.13171-1-kirill.shutemov@linux.intel.com> <20190508144422.13171-50-kirill.shutemov@linux.intel.com> <20190614115647.GI3436@hirez.programming.kicks-ass.net> <1560741269.5187.7.camel@linux.intel.com> <20190617074643.GW3436@hirez.programming.kicks-ass.net> <1560760783.5187.10.camel@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1560760783.5187.10.camel@linux.intel.com> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 17, 2019 at 08:39:43PM +1200, Kai Huang wrote: > On Mon, 2019-06-17 at 09:46 +0200, Peter Zijlstra wrote: > > On Mon, Jun 17, 2019 at 03:14:29PM +1200, Kai Huang wrote: > > > On Fri, 2019-06-14 at 13:56 +0200, Peter Zijlstra wrote: > > > > On Wed, May 08, 2019 at 05:44:09PM +0300, Kirill A. Shutemov wrote: > > > > > From: Kai Huang > > > > > > > > > > KVM needs those variables to get/set memory encryption mask. > > > > > > > > > > Signed-off-by: Kai Huang > > > > > Signed-off-by: Kirill A. Shutemov > > > > > --- > > > > > arch/x86/mm/mktme.c | 3 +++ > > > > > 1 file changed, 3 insertions(+) > > > > > > > > > > diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c > > > > > index df70651816a1..12f4266cf7ea 100644 > > > > > --- a/arch/x86/mm/mktme.c > > > > > +++ b/arch/x86/mm/mktme.c > > > > > @@ -7,13 +7,16 @@ > > > > > > > > > > /* Mask to extract KeyID from physical address. */ > > > > > phys_addr_t mktme_keyid_mask; > > > > > +EXPORT_SYMBOL_GPL(mktme_keyid_mask); > > > > > /* > > > > > * Number of KeyIDs available for MKTME. > > > > > * Excludes KeyID-0 which used by TME. MKTME KeyIDs start from 1. > > > > > */ > > > > > int mktme_nr_keyids; > > > > > +EXPORT_SYMBOL_GPL(mktme_nr_keyids); > > > > > /* Shift of KeyID within physical address. */ > > > > > int mktme_keyid_shift; > > > > > +EXPORT_SYMBOL_GPL(mktme_keyid_shift); > > > > > > > > > > DEFINE_STATIC_KEY_FALSE(mktme_enabled_key); > > > > > EXPORT_SYMBOL_GPL(mktme_enabled_key); > > > > > > > > NAK, don't export variables. Who owns the values, who enforces this? > > > > > > > > > > Both KVM and IOMMU driver need page_keyid() and mktme_keyid_shift to set page's keyID to the > > > right > > > place in the PTE (of KVM EPT and VT-d DMA page table). > > > > > > MKTME key type code need to know mktme_nr_keyids in order to alloc/free keyID. > > > > > > Maybe better to introduce functions instead of exposing variables directly? > > > > > > Or instead of introducing page_keyid(), we use page_encrypt_mask(), which essentially holds > > > "page_keyid() << mktme_keyid_shift"? > > > > Yes, that's much better, because that strictly limits the access to R/O. > > > > Thanks. I think Kirill will be the one to handle your suggestion. :) > > Kirill? Will do. -- Kirill A. Shutemov