Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751031AbdGZE3Z (ORCPT ); Wed, 26 Jul 2017 00:29:25 -0400 Received: from mx2.suse.de ([195.135.220.15]:44819 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750813AbdGZE3X (ORCPT ); Wed, 26 Jul 2017 00:29:23 -0400 Date: Wed, 26 Jul 2017 06:28:40 +0200 From: Borislav Petkov To: 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 , Tom Lendacky , 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 , Radim =?utf-8?B?S3LEjW3DocWZ?= , Arnd Bergmann , Tejun Heo , Christoph Lameter Subject: Re: [RFC Part1 PATCH v3 03/17] x86/mm: Secure Encrypted Virtualization (SEV) support Message-ID: <20170726042840.GB30702@nazgul.tnic> References: <20170724190757.11278-1-brijesh.singh@amd.com> <20170724190757.11278-4-brijesh.singh@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170724190757.11278-4-brijesh.singh@amd.com> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2428 Lines: 78 On Mon, Jul 24, 2017 at 02:07:43PM -0500, Brijesh Singh wrote: > From: Tom Lendacky > > Provide support for Secure Encyrpted Virtualization (SEV). This initial Your subject misses a verb and patch subjects should have an active verb denoting what the patch does. The sentence above is a good example. > support defines a flag that is used by the kernel to determine if it is > running with SEV active. > > Signed-off-by: Tom Lendacky > Signed-off-by: Brijesh Singh > --- > arch/x86/include/asm/mem_encrypt.h | 2 ++ > arch/x86/mm/mem_encrypt.c | 3 +++ > include/linux/mem_encrypt.h | 8 +++++++- > 3 files changed, 12 insertions(+), 1 deletion(-) ... > diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c > index 0fbd092..1e4643e 100644 > --- a/arch/x86/mm/mem_encrypt.c > +++ b/arch/x86/mm/mem_encrypt.c > @@ -40,6 +40,9 @@ static char sme_cmdline_off[] __initdata = "off"; > unsigned long sme_me_mask __section(.data) = 0; > EXPORT_SYMBOL_GPL(sme_me_mask); > > +unsigned int sev_enabled __section(.data) = 0; > +EXPORT_SYMBOL_GPL(sev_enabled); So sev_enabled is a pure bool used only in bool context, not like sme_me_mask whose value is read too. Which means, you can make the former static and query it only through accessor functions. > /* Buffer used for early in-place encryption by BSP, no locking needed */ > static char sme_early_buffer[PAGE_SIZE] __aligned(PAGE_SIZE); > > diff --git a/include/linux/mem_encrypt.h b/include/linux/mem_encrypt.h > index 1255f09..ea0831a 100644 > --- a/include/linux/mem_encrypt.h > +++ b/include/linux/mem_encrypt.h > @@ -22,12 +22,18 @@ > #else /* !CONFIG_ARCH_HAS_MEM_ENCRYPT */ > > #define sme_me_mask 0UL > +#define sev_enabled 0 > > #endif /* CONFIG_ARCH_HAS_MEM_ENCRYPT */ > > static inline bool sme_active(void) > { > - return !!sme_me_mask; > + return (sme_me_mask && !sev_enabled); You don't need the brackets. Below too. > +} > + > +static inline bool sev_active(void) > +{ > + return (sme_me_mask && sev_enabled); > } So this is confusing, TBH. SME and SEV are not mutually exclusive and yet the logic here says so. Why? I mean, in the hypervisor context, sme_active() is still true. /me is confused. -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --