From patchwork Mon Nov 29 11:42:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dov Murik X-Patchwork-Id: 517008 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BBB38C4332F for ; Mon, 29 Nov 2021 11:45:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243110AbhK2Lsu (ORCPT ); Mon, 29 Nov 2021 06:48:50 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:24310 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S233088AbhK2Lqq (ORCPT ); Mon, 29 Nov 2021 06:46:46 -0500 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 1ATAlrwu012306; Mon, 29 Nov 2021 11:43:04 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=kamyNYTZdW+Ck7AYBaVkPVYS8nretLoAiG2thK5BPGY=; b=dMoUlmYDgVpW/kBKnHx1lrec//qCnAruvtkoWl9MYRZhwKZY/LqSNm2wYea5jPoUlDMn dCAQXtD6yWgThDUlH24cenPfKxxD+2q9mlfGtEtG7i5GDYSNeEZzzf1PCC/Gqr1iLkO6 9ZZHpaiuBnUk+65RhuI7IqiZN/YJe729n62tb9q76UIkQXPS3ZiHUrQaa57cfdWrq3Z4 rnbedHM6fEko1JF1PgnVb+rp5xME2s5pjjvJe+J4ajgSXVtOwZdeFSCy+mI03dFG2gZn Q3CBo01FuvAkLpIUmHcIOlvD7R2Iyud+WpNmpckdB+DxDIAP423DcYHgs4AOT/fNJwTv /w== Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 3cmwdv1608-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Nov 2021 11:43:03 +0000 Received: from m0098414.ppops.net (m0098414.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 1ATBVcr6023959; Mon, 29 Nov 2021 11:43:03 GMT Received: from ppma04wdc.us.ibm.com (1a.90.2fa9.ip4.static.sl-reverse.com [169.47.144.26]) by mx0b-001b2d01.pphosted.com with ESMTP id 3cmwdv15yx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Nov 2021 11:43:03 +0000 Received: from pps.filterd (ppma04wdc.us.ibm.com [127.0.0.1]) by ppma04wdc.us.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 1ATBXRWa002634; Mon, 29 Nov 2021 11:43:02 GMT Received: from b01cxnp22034.gho.pok.ibm.com (b01cxnp22034.gho.pok.ibm.com [9.57.198.24]) by ppma04wdc.us.ibm.com with ESMTP id 3ckcaafcbu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Nov 2021 11:43:02 +0000 Received: from b01ledav002.gho.pok.ibm.com (b01ledav002.gho.pok.ibm.com [9.57.199.107]) by b01cxnp22034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 1ATBgxNW23921104 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 29 Nov 2021 11:43:00 GMT Received: from b01ledav002.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D7F2E124052; Mon, 29 Nov 2021 11:42:59 +0000 (GMT) Received: from b01ledav002.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 816FC124054; Mon, 29 Nov 2021 11:42:59 +0000 (GMT) Received: from amdrome3.watson.ibm.com (unknown [9.2.130.16]) by b01ledav002.gho.pok.ibm.com (Postfix) with ESMTP; Mon, 29 Nov 2021 11:42:59 +0000 (GMT) From: Dov Murik To: linux-efi@vger.kernel.org Cc: Dov Murik , Borislav Petkov , Ashish Kalra , Brijesh Singh , Tom Lendacky , Ard Biesheuvel , James Morris , "Serge E. Hallyn" , Andi Kleen , Greg KH , Andrew Scull , Dave Hansen , "Dr. David Alan Gilbert" , James Bottomley , Tobin Feldman-Fitzthum , Jim Cadden , Daniele Buono , linux-coco@lists.linux.dev, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v6 1/5] efi: Save location of EFI confidential computing area Date: Mon, 29 Nov 2021 11:42:47 +0000 Message-Id: <20211129114251.3741721-2-dovmurik@linux.ibm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211129114251.3741721-1-dovmurik@linux.ibm.com> References: <20211129114251.3741721-1-dovmurik@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: gmJJhpFDY0Y2T656Hx657pOgYmlBh7p0 X-Proofpoint-ORIG-GUID: pYB7Mhmv87wke79CMI8-RAysp07vTqKK X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.0.607.475 definitions=2021-11-29_07,2021-11-28_01,2020-04-07_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 mlxscore=0 spamscore=0 adultscore=0 phishscore=0 malwarescore=0 mlxlogscore=999 suspectscore=0 clxscore=1015 impostorscore=0 bulkscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000 definitions=main-2111290058 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Confidential computing (coco) hardware such as AMD SEV (Secure Encrypted Virtualization) allows a guest owner to inject secrets into the VMs memory without the host/hypervisor being able to read them. Firmware support for secret injection is available in OVMF, which reserves a memory area for secret injection and includes a pointer to it the in EFI config table entry LINUX_EFI_COCO_SECRET_TABLE_GUID. If EFI exposes such a table entry, uefi_init() will keep a pointer to the EFI config table entry in efi.coco_secret, so it can be used later by the kernel (specifically drivers/virt/coco/efi_secret). It will also appear in the kernel log as "CocoSecret=ADDRESS"; for example: [ 0.000000] efi: EFI v2.70 by EDK II [ 0.000000] efi: CocoSecret=0x7f22e680 SMBIOS=0x7f541000 ACPI=0x7f77e000 ACPI 2.0=0x7f77e014 MEMATTR=0x7ea0c018 The new functionality can be enabled with CONFIG_EFI_COCO_SECRET=y. Signed-off-by: Dov Murik --- arch/x86/platform/efi/efi.c | 3 +++ drivers/firmware/efi/Kconfig | 16 ++++++++++++++++ drivers/firmware/efi/efi.c | 6 ++++++ include/linux/efi.h | 10 ++++++++++ 4 files changed, 35 insertions(+) diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 147c30a81f15..1591d67e0bcd 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -93,6 +93,9 @@ static const unsigned long * const efi_tables[] = { #ifdef CONFIG_LOAD_UEFI_KEYS &efi.mokvar_table, #endif +#ifdef CONFIG_EFI_COCO_SECRET + &efi.coco_secret, +#endif }; u64 efi_setup; /* efi setup_data physical address */ diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 2c3dac5ecb36..6fa251b3709f 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -284,3 +284,19 @@ config EFI_CUSTOM_SSDT_OVERLAYS See Documentation/admin-guide/acpi/ssdt-overlays.rst for more information. + +config EFI_COCO_SECRET + bool "EFI Confidential Computing Secret Area Support" + depends on EFI + help + Confidential Computing platforms (such as AMD SEV) allow the + Guest Owner to securely inject secrets during guest VM launch. + The secrets are placed in a designated EFI reserved memory area. + + In order to use the secrets in the kernel, the location of the secret + area (as published in the EFI config table) must be kept. + + If you say Y here, the address of the EFI secret area will be kept + for usage inside the kernel. This will allow the + virt/coco/efi_secret module to access the secrets, which in turn + allows userspace programs to access the injected secrets. diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index ae79c3300129..3cc3a7449c64 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -46,6 +46,9 @@ struct efi __read_mostly efi = { #ifdef CONFIG_LOAD_UEFI_KEYS .mokvar_table = EFI_INVALID_TABLE_ADDR, #endif +#ifdef CONFIG_EFI_COCO_SECRET + .coco_secret = EFI_INVALID_TABLE_ADDR, +#endif }; EXPORT_SYMBOL(efi); @@ -528,6 +531,9 @@ static const efi_config_table_type_t common_tables[] __initconst = { #endif #ifdef CONFIG_LOAD_UEFI_KEYS {LINUX_EFI_MOK_VARIABLE_TABLE_GUID, &efi.mokvar_table, "MOKvar" }, +#endif +#ifdef CONFIG_EFI_COCO_SECRET + {LINUX_EFI_COCO_SECRET_AREA_GUID, &efi.coco_secret, "CocoSecret" }, #endif {}, }; diff --git a/include/linux/efi.h b/include/linux/efi.h index dbd39b20e034..f68aa768a4e2 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -359,6 +359,7 @@ void efi_native_runtime_setup(void); #define LINUX_EFI_MEMRESERVE_TABLE_GUID EFI_GUID(0x888eb0c6, 0x8ede, 0x4ff5, 0xa8, 0xf0, 0x9a, 0xee, 0x5c, 0xb9, 0x77, 0xc2) #define LINUX_EFI_INITRD_MEDIA_GUID EFI_GUID(0x5568e427, 0x68fc, 0x4f3d, 0xac, 0x74, 0xca, 0x55, 0x52, 0x31, 0xcc, 0x68) #define LINUX_EFI_MOK_VARIABLE_TABLE_GUID EFI_GUID(0xc451ed2b, 0x9694, 0x45d3, 0xba, 0xba, 0xed, 0x9f, 0x89, 0x88, 0xa3, 0x89) +#define LINUX_EFI_COCO_SECRET_AREA_GUID EFI_GUID(0xadf956ad, 0xe98c, 0x484c, 0xae, 0x11, 0xb5, 0x1c, 0x7d, 0x33, 0x64, 0x47) /* OEM GUIDs */ #define DELLEMC_EFI_RCI2_TABLE_GUID EFI_GUID(0x2d9f28a2, 0xa886, 0x456a, 0x97, 0xa8, 0xf1, 0x1e, 0xf2, 0x4f, 0xf4, 0x55) @@ -550,6 +551,7 @@ extern struct efi { unsigned long tpm_log; /* TPM2 Event Log table */ unsigned long tpm_final_log; /* TPM2 Final Events Log table */ unsigned long mokvar_table; /* MOK variable config table */ + unsigned long coco_secret; /* Confidential computing secret table */ efi_get_time_t *get_time; efi_set_time_t *set_time; @@ -1283,4 +1285,12 @@ static inline struct efi_mokvar_table_entry *efi_mokvar_entry_find( } #endif +struct linux_efi_coco_secret_area { + u64 base_pa; + u64 size; +}; + +/* Header of a populated EFI secret area */ +#define EFI_SECRET_TABLE_HEADER_GUID EFI_GUID(0x1e74f542, 0x71dd, 0x4d66, 0x96, 0x3e, 0xef, 0x42, 0x87, 0xff, 0x17, 0x3b) + #endif /* _LINUX_EFI_H */