From patchwork Mon Nov 13 02:23:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= X-Patchwork-Id: 13453521 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 059165232 for ; Mon, 13 Nov 2023 02:24:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=digikod.net header.i=@digikod.net header.b="bV4lvDvQ" Received: from smtp-190a.mail.infomaniak.ch (smtp-190a.mail.infomaniak.ch [IPv6:2001:1600:4:17::190a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA6581BF7 for ; Sun, 12 Nov 2023 18:24:00 -0800 (PST) Received: from smtp-3-0000.mail.infomaniak.ch (unknown [10.4.36.107]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4STCsp5jGkzMpvS5; Mon, 13 Nov 2023 02:23:58 +0000 (UTC) Received: from unknown by smtp-3-0000.mail.infomaniak.ch (Postfix) with ESMTPA id 4STCsn4w8yz3W; Mon, 13 Nov 2023 03:23:57 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=digikod.net; s=20191114; t=1699842238; bh=tY8hlJfPopuy154H09Cr6nqcw/h0DUTJ1/nUw09u9eU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bV4lvDvQTCac2IMzSmZNNLVBOtTqAuS2XLzxMp+OAzsv+rke/FG2TXyxhi8G9+60p uVBBHLsVIDwfgY2jYAyUCw2LIYtSt/u33MBaH9fX9Ljjyq03aPdOVNbFjYzptoLzUl mUsHCWJz6tf9YxVBhc8meVQg8fYV2sX1kdkepvvo= From: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= To: Borislav Petkov , Dave Hansen , "H . Peter Anvin" , Ingo Molnar , Kees Cook , Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Vitaly Kuznetsov , Wanpeng Li Cc: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= , Alexander Graf , Chao Peng , "Edgecombe, Rick P" , Forrest Yuan Yu , James Gowans , James Morris , John Andersen , "Madhavan T . Venkataraman" , Marian Rotariu , =?utf-8?q?Mihai_Don=C8=9Bu?= , =?utf-8?b?TmljdciZ?= =?utf-8?b?b3IgQ8OuyJt1?= , Thara Gopinath , Trilok Soni , Wei Liu , Will Deacon , Yu Zhang , Zahra Tarkhani , =?utf-8?q?=C8=98tefan_=C8=98icler?= =?utf-8?q?u?= , dev@lists.cloudhypervisor.org, kvm@vger.kernel.org, linux-hardening@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, x86@kernel.org, xen-devel@lists.xenproject.org Subject: [RFC PATCH v2 01/19] virt: Introduce Hypervisor Enforced Kernel Integrity (Heki) Date: Sun, 12 Nov 2023 21:23:08 -0500 Message-ID: <20231113022326.24388-2-mic@digikod.net> In-Reply-To: <20231113022326.24388-1-mic@digikod.net> References: <20231113022326.24388-1-mic@digikod.net> Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Infomaniak-Routing: alpha From: Madhavan T. Venkataraman Hypervisor Enforced Kernel Integrity (Heki) is a feature that will use the hypervisor to enhance guest virtual machine security. Implement minimal code to introduce Heki: - Define the config variables. - Define a kernel command line parameter "heki" to turn the feature on or off. By default, Heki is on. - Define heki_early_init() and call it in start_kernel(). Currently, this function only prints the value of the "heki" command line parameter. Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Kees Cook Cc: Paolo Bonzini Cc: Sean Christopherson Cc: Thomas Gleixner Cc: Vitaly Kuznetsov Cc: Wanpeng Li Co-developed-by: Mickaël Salaün Signed-off-by: Mickaël Salaün Signed-off-by: Madhavan T. Venkataraman --- Changes since v1: * Shrinked this patch to only contain the minimal common parts. * Moved heki_early_init() to start_kernel(). --- Kconfig | 2 ++ arch/x86/Kconfig | 1 + include/linux/heki.h | 31 +++++++++++++++++++++++++++++++ init/main.c | 2 ++ mm/mm_init.c | 1 + virt/Makefile | 1 + virt/heki/Kconfig | 19 +++++++++++++++++++ virt/heki/Makefile | 3 +++ virt/heki/common.h | 16 ++++++++++++++++ virt/heki/main.c | 32 ++++++++++++++++++++++++++++++++ 10 files changed, 108 insertions(+) create mode 100644 include/linux/heki.h create mode 100644 virt/heki/Kconfig create mode 100644 virt/heki/Makefile create mode 100644 virt/heki/common.h create mode 100644 virt/heki/main.c diff --git a/Kconfig b/Kconfig index 745bc773f567..0c844d9bcb03 100644 --- a/Kconfig +++ b/Kconfig @@ -29,4 +29,6 @@ source "lib/Kconfig" source "lib/Kconfig.debug" +source "virt/heki/Kconfig" + source "Documentation/Kconfig" diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 66bfabae8814..424f949442bd 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -35,6 +35,7 @@ config X86_64 select SWIOTLB select ARCH_HAS_ELFCORE_COMPAT select ZONE_DMA32 + select ARCH_SUPPORTS_HEKI config FORCE_DYNAMIC_FTRACE def_bool y diff --git a/include/linux/heki.h b/include/linux/heki.h new file mode 100644 index 000000000000..4c18d2283392 --- /dev/null +++ b/include/linux/heki.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Hypervisor Enforced Kernel Integrity (Heki) - Definitions + * + * Copyright © 2023 Microsoft Corporation + */ + +#ifndef __HEKI_H__ +#define __HEKI_H__ + +#include +#include +#include +#include +#include + +#ifdef CONFIG_HEKI + +extern bool heki_enabled; + +void heki_early_init(void); + +#else /* !CONFIG_HEKI */ + +static inline void heki_early_init(void) +{ +} + +#endif /* CONFIG_HEKI */ + +#endif /* __HEKI_H__ */ diff --git a/init/main.c b/init/main.c index 436d73261810..0d28301c5402 100644 --- a/init/main.c +++ b/init/main.c @@ -99,6 +99,7 @@ #include #include #include +#include #include #include @@ -1047,6 +1048,7 @@ void start_kernel(void) uts_ns_init(); key_init(); security_init(); + heki_early_init(); dbg_late_init(); net_ns_init(); vfs_caches_init(); diff --git a/mm/mm_init.c b/mm/mm_init.c index 50f2f34745af..896977383cc3 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -26,6 +26,7 @@ #include #include #include +#include #include "internal.h" #include "slab.h" #include "shuffle.h" diff --git a/virt/Makefile b/virt/Makefile index 1cfea9436af9..4550dc624466 100644 --- a/virt/Makefile +++ b/virt/Makefile @@ -1,2 +1,3 @@ # SPDX-License-Identifier: GPL-2.0-only obj-y += lib/ +obj-$(CONFIG_HEKI) += heki/ diff --git a/virt/heki/Kconfig b/virt/heki/Kconfig new file mode 100644 index 000000000000..49695fff6d21 --- /dev/null +++ b/virt/heki/Kconfig @@ -0,0 +1,19 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Hypervisor Enforced Kernel Integrity (Heki) + +config HEKI + bool "Hypervisor Enforced Kernel Integrity (Heki)" + depends on ARCH_SUPPORTS_HEKI + help + This feature enhances guest virtual machine security by taking + advantage of security features provided by the hypervisor for guests. + This feature is helpful in maintaining guest virtual machine security + even after the guest kernel has been compromised. + +config ARCH_SUPPORTS_HEKI + bool "Architecture support for Heki" + help + An architecture should select this when it can successfully build + and run with CONFIG_HEKI. That is, it should provide all of the + architecture support required for the HEKI feature. diff --git a/virt/heki/Makefile b/virt/heki/Makefile new file mode 100644 index 000000000000..354e567df71c --- /dev/null +++ b/virt/heki/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only + +obj-y += main.o diff --git a/virt/heki/common.h b/virt/heki/common.h new file mode 100644 index 000000000000..edd98fc650a8 --- /dev/null +++ b/virt/heki/common.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Hypervisor Enforced Kernel Integrity (Heki) - Common header + * + * Copyright © 2023 Microsoft Corporation + */ + +#ifndef _HEKI_COMMON_H + +#ifdef pr_fmt +#undef pr_fmt +#endif + +#define pr_fmt(fmt) "heki-guest: " fmt + +#endif /* _HEKI_COMMON_H */ diff --git a/virt/heki/main.c b/virt/heki/main.c new file mode 100644 index 000000000000..f005dd74d586 --- /dev/null +++ b/virt/heki/main.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Hypervisor Enforced Kernel Integrity (Heki) - Common code + * + * Copyright © 2023 Microsoft Corporation + */ + +#include + +#include "common.h" + +bool heki_enabled __ro_after_init = true; + +/* + * Must be called after kmem_cache_init(). + */ +__init void heki_early_init(void) +{ + if (!heki_enabled) { + pr_warn("Heki is not enabled\n"); + return; + } + pr_warn("Heki is enabled\n"); +} + +static int __init heki_parse_config(char *str) +{ + if (strtobool(str, &heki_enabled)) + pr_warn("Invalid option string for heki: '%s'\n", str); + return 1; +} +__setup("heki=", heki_parse_config);