From patchwork Tue Sep 28 19:10:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Borislav Petkov X-Patchwork-Id: 12523613 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4F6D0C433EF for ; Tue, 28 Sep 2021 19:10:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36DE46136F for ; Tue, 28 Sep 2021 19:10:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242411AbhI1TME (ORCPT ); Tue, 28 Sep 2021 15:12:04 -0400 Received: from mail.skyhub.de ([5.9.137.197]:41122 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242218AbhI1TMB (ORCPT ); Tue, 28 Sep 2021 15:12:01 -0400 Received: from zn.tnic (p200300ec2f13b20078349fd04295260b.dip0.t-ipconnect.de [IPv6:2003:ec:2f13:b200:7834:9fd0:4295:260b]) (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 03EEF1EC0731; Tue, 28 Sep 2021 21:10:20 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1632856220; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=J+XdhoQGzIN8rz2Q4VHmTGzW5OUUAI4zbVurx/C+SFw=; b=Yo909OX92n3M/cGLqS77ordtgA2tox4iPDFQFfqj90ti7VPQU2IrUuYwnMJGopwHyUg8Ex 7pnCy6+oJgxD0E3vHZ0scxdMTXevKG3dVm9jvPA9z/Saeugp83kcj6Kifc6iNEhP1gH4KW aK+6e6Rz0t6QBeUqkA4X9sqEff7rZcg= From: Borislav Petkov To: LKML Cc: Andi Kleen , Kuppuswamy Sathyanarayanan , Andy Lutomirski , Ard Biesheuvel , Baoquan He , Benjamin Herrenschmidt , Christian Borntraeger , Daniel Vetter , Dave Young , David Airlie , Heiko Carstens , Joerg Roedel , "Kirill A. Shutemov" , Maarten Lankhorst , Maxime Ripard , Michael Ellerman , Paul Mackerras , Tom Lendacky , Thomas Zimmermann , Vasily Gorbik , VMware Graphics , Will Deacon , Christoph Hellwig , x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, iommu@lists.linux-foundation.org, kvm@vger.kernel.org, linux-efi@vger.kernel.org, platform-driver-x86@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, kexec@lists.infradead.org Subject: [PATCH 2/8] arch/cc: Introduce a function to check for confidential computing features Date: Tue, 28 Sep 2021 21:10:03 +0200 Message-Id: <20210928191009.32551-3-bp@alien8.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210928191009.32551-1-bp@alien8.de> References: <20210928191009.32551-1-bp@alien8.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org From: Tom Lendacky In preparation for other confidential computing technologies, introduce a generic helper function, cc_platform_has(), that can be used to check for specific active confidential computing attributes, like memory encryption. This is intended to eliminate having to add multiple technology-specific checks to the code (e.g. if (sev_active() || tdx_active() || ... ). [ bp: s/_CC_PLATFORM_H/_LINUX_CC_PLATFORM_H/g ] Co-developed-by: Andi Kleen Signed-off-by: Andi Kleen Co-developed-by: Kuppuswamy Sathyanarayanan Signed-off-by: Kuppuswamy Sathyanarayanan Signed-off-by: Tom Lendacky Signed-off-by: Borislav Petkov --- arch/Kconfig | 3 ++ include/linux/cc_platform.h | 88 +++++++++++++++++++++++++++++++++++++ 2 files changed, 91 insertions(+) create mode 100644 include/linux/cc_platform.h diff --git a/arch/Kconfig b/arch/Kconfig index 8df1c7102643..d1e69d6e8498 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1234,6 +1234,9 @@ config RELR config ARCH_HAS_MEM_ENCRYPT bool +config ARCH_HAS_CC_PLATFORM + bool + config HAVE_SPARSE_SYSCALL_NR bool help diff --git a/include/linux/cc_platform.h b/include/linux/cc_platform.h new file mode 100644 index 000000000000..a075b70b9a70 --- /dev/null +++ b/include/linux/cc_platform.h @@ -0,0 +1,88 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Confidential Computing Platform Capability checks + * + * Copyright (C) 2021 Advanced Micro Devices, Inc. + * + * Author: Tom Lendacky + */ + +#ifndef _LINUX_CC_PLATFORM_H +#define _LINUX_CC_PLATFORM_H + +#include +#include + +/** + * enum cc_attr - Confidential computing attributes + * + * These attributes represent confidential computing features that are + * currently active. + */ +enum cc_attr { + /** + * @CC_ATTR_MEM_ENCRYPT: Memory encryption is active + * + * The platform/OS is running with active memory encryption. This + * includes running either as a bare-metal system or a hypervisor + * and actively using memory encryption or as a guest/virtual machine + * and actively using memory encryption. + * + * Examples include SME, SEV and SEV-ES. + */ + CC_ATTR_MEM_ENCRYPT, + + /** + * @CC_ATTR_HOST_MEM_ENCRYPT: Host memory encryption is active + * + * The platform/OS is running as a bare-metal system or a hypervisor + * and actively using memory encryption. + * + * Examples include SME. + */ + CC_ATTR_HOST_MEM_ENCRYPT, + + /** + * @CC_ATTR_GUEST_MEM_ENCRYPT: Guest memory encryption is active + * + * The platform/OS is running as a guest/virtual machine and actively + * using memory encryption. + * + * Examples include SEV and SEV-ES. + */ + CC_ATTR_GUEST_MEM_ENCRYPT, + + /** + * @CC_ATTR_GUEST_STATE_ENCRYPT: Guest state encryption is active + * + * The platform/OS is running as a guest/virtual machine and actively + * using memory encryption and register state encryption. + * + * Examples include SEV-ES. + */ + CC_ATTR_GUEST_STATE_ENCRYPT, +}; + +#ifdef CONFIG_ARCH_HAS_CC_PLATFORM + +/** + * cc_platform_has() - Checks if the specified cc_attr attribute is active + * @attr: Confidential computing attribute to check + * + * The cc_platform_has() function will return an indicator as to whether the + * specified Confidential Computing attribute is currently active. + * + * Context: Any context + * Return: + * * TRUE - Specified Confidential Computing attribute is active + * * FALSE - Specified Confidential Computing attribute is not active + */ +bool cc_platform_has(enum cc_attr attr); + +#else /* !CONFIG_ARCH_HAS_CC_PLATFORM */ + +static inline bool cc_platform_has(enum cc_attr attr) { return false; } + +#endif /* CONFIG_ARCH_HAS_CC_PLATFORM */ + +#endif /* _LINUX_CC_PLATFORM_H */