From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from NAM01-SN1-obe.outbound.protection.outlook.com (mail-sn1nam01on0077.outbound.protection.outlook.com [104.47.32.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3xYDmP6l09zDqlm for ; Fri, 18 Aug 2017 04:11:01 +1000 (AEST) Subject: Re: [RFC Part1 PATCH v3 07/17] x86/mm: Include SEV for encryption memory attribute changes To: Borislav Petkov , Brijesh Singh Cc: linux-kernel@vger.kernel.org, x86@kernel.org, linux-efi@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Andy Lutomirski , Tony Luck , Piotr Luc , Fenghua Yu , Lu Baolu , Reza Arbab , David Howells , Matt Fleming , "Kirill A . Shutemov" , Laura Abbott , Ard Biesheuvel , Andrew Morton , Eric Biederman , Benjamin Herrenschmidt , Paul Mackerras , Konrad Rzeszutek Wilk , Jonathan Corbet , Dave Airlie , Kees Cook , Paolo Bonzini , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Arnd Bergmann , Tejun Heo , Christoph Lameter References: <20170724190757.11278-1-brijesh.singh@amd.com> <20170724190757.11278-8-brijesh.singh@amd.com> <20170727145841.GG28553@nazgul.tnic> From: Tom Lendacky Message-ID: Date: Thu, 17 Aug 2017 13:10:45 -0500 MIME-Version: 1.0 In-Reply-To: <20170727145841.GG28553@nazgul.tnic> Content-Type: text/plain; charset=utf-8; format=flowed List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 7/27/2017 9:58 AM, Borislav Petkov wrote: > On Mon, Jul 24, 2017 at 02:07:47PM -0500, Brijesh Singh wrote: >> From: Tom Lendacky >> >> The current code checks only for sme_active() when determining whether >> to perform the encryption attribute change. Include sev_active() in this >> check so that memory attribute changes can occur under SME and SEV. >> >> Signed-off-by: Tom Lendacky >> Signed-off-by: Brijesh Singh >> --- >> arch/x86/mm/pageattr.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c >> index dfb7d65..b726b23 100644 >> --- a/arch/x86/mm/pageattr.c >> +++ b/arch/x86/mm/pageattr.c >> @@ -1781,8 +1781,8 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) >> unsigned long start; >> int ret; >> >> - /* Nothing to do if the SME is not active */ >> - if (!sme_active()) >> + /* Nothing to do if SME and SEV are not active */ >> + if (!sme_active() && !sev_active()) > > This is the second place which does > > if (!SME && !SEV) > > I wonder if, instead of sprinking those, we should have a > > if (mem_enc_active()) > > or so which unifies all those memory encryption logic tests and makes > the code more straightforward for readers who don't have to pay > attention to SME vs SEV ... Yup, that will make things look cleaner and easier to understand. Thanks, Tom > > Just a thought. >