From patchwork Thu Oct 7 06:18:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dov Murik X-Patchwork-Id: 12540981 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 42E85C433FE for ; Thu, 7 Oct 2021 06:19:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2CA156113E for ; Thu, 7 Oct 2021 06:19:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240253AbhJGGVF (ORCPT ); Thu, 7 Oct 2021 02:21:05 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:19770 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240216AbhJGGVC (ORCPT ); Thu, 7 Oct 2021 02:21:02 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 1975dRF5008889; Thu, 7 Oct 2021 02:18:45 -0400 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=VZIyRqthO6pl/kMcGKnVcZFJWGn3auCwdoSboG+e8xA=; b=kEOfxVEA3mRWYeNMpr4XeUnQc328vUwKZVqGjNYVxvwX2kcM8sTc27rioVpCirQPk143 eP/qDoJ0IC6E8fEmmccLrs7vJrnt65H/YfZ1EmVgw2m+nvYaQh9SkcIwqwuM7y8Wmw2g p/qB8m8KSbwuyVMxFALXk5EKVpkGL1brturEJ5EaV0yPUrlwfaHY9Gx0dnwFqGEaqfg4 dlCxMhmqNWOJ3e+Ds7I62eTvMBNQk7bKR3zyXlkeIjSTHEuyzNn2OC8D25zxOGxwGQG1 17JAmzsvjma6oDOfSdF5qo56OlRQs6UcD6zjtJYXap5H/WXQbrCgmZstOMLPVxKiB+MA yg== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3bhkcx17mg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 07 Oct 2021 02:18:45 -0400 Received: from m0098396.ppops.net (m0098396.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 1975mPqG007928; Thu, 7 Oct 2021 02:18:44 -0400 Received: from ppma01wdc.us.ibm.com (fd.55.37a9.ip4.static.sl-reverse.com [169.55.85.253]) by mx0a-001b2d01.pphosted.com with ESMTP id 3bhkcx17ky-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 07 Oct 2021 02:18:44 -0400 Received: from pps.filterd (ppma01wdc.us.ibm.com [127.0.0.1]) by ppma01wdc.us.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 1976Hsq1032341; Thu, 7 Oct 2021 06:18:43 GMT Received: from b01cxnp23034.gho.pok.ibm.com (b01cxnp23034.gho.pok.ibm.com [9.57.198.29]) by ppma01wdc.us.ibm.com with ESMTP id 3bef2bsuep-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 07 Oct 2021 06:18:43 +0000 Received: from b01ledav005.gho.pok.ibm.com (b01ledav005.gho.pok.ibm.com [9.57.199.110]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 1976Ifpe42533262 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 7 Oct 2021 06:18:41 GMT Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 76468AE063; Thu, 7 Oct 2021 06:18:41 +0000 (GMT) Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1F9FCAE066; Thu, 7 Oct 2021 06:18:41 +0000 (GMT) Received: from amdrome3.watson.ibm.com (unknown [9.2.130.16]) by b01ledav005.gho.pok.ibm.com (Postfix) with ESMTP; Thu, 7 Oct 2021 06:18:41 +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 , "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 v2 1/4] x86: Export clean_cache_range() Date: Thu, 7 Oct 2021 06:18:35 +0000 Message-Id: <20211007061838.1381129-2-dovmurik@linux.ibm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211007061838.1381129-1-dovmurik@linux.ibm.com> References: <20211007061838.1381129-1-dovmurik@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: nS7OZlRa22gZYQdylIC3i34dfCSB_Jfc X-Proofpoint-ORIG-GUID: c_LBawc6OxqucSbZGPuFu_Nd6JHtSM-9 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.182.1,Aquarius:18.0.790,Hydra:6.0.391,FMLib:17.0.607.475 definitions=2021-10-06_04,2021-10-07_01,2020-04-07_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 mlxscore=0 suspectscore=0 bulkscore=0 lowpriorityscore=0 malwarescore=0 mlxlogscore=999 priorityscore=1501 phishscore=0 spamscore=0 impostorscore=0 clxscore=1011 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2109230001 definitions=main-2110070039 Precedence: bulk List-ID: Export clean_cache_range() which is similar to the existing clflush_cache_range() but uses the CLWB (cache line write back) instruction instead of CLFLUSH. Remove existing implementation of clean_cache_range() from arch/x86/lib/usercopy_64.c . Signed-off-by: Dov Murik --- arch/x86/include/asm/cacheflush.h | 1 + arch/x86/lib/usercopy_64.c | 21 --------------------- arch/x86/mm/pat/set_memory.c | 30 ++++++++++++++++++++++++++++++ 3 files changed, 31 insertions(+), 21 deletions(-) diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h index b192d917a6d0..76452ba1bafb 100644 --- a/arch/x86/include/asm/cacheflush.h +++ b/arch/x86/include/asm/cacheflush.h @@ -9,5 +9,6 @@ #include void clflush_cache_range(void *addr, unsigned int size); +void clean_cache_range(void *vaddr, unsigned int size); #endif /* _ASM_X86_CACHEFLUSH_H */ diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c index 508c81e97ab1..ffd39f1d4251 100644 --- a/arch/x86/lib/usercopy_64.c +++ b/arch/x86/lib/usercopy_64.c @@ -57,27 +57,6 @@ unsigned long clear_user(void __user *to, unsigned long n) EXPORT_SYMBOL(clear_user); #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE -/** - * clean_cache_range - write back a cache range with CLWB - * @vaddr: virtual start address - * @size: number of bytes to write back - * - * Write back a cache range using the CLWB (cache line write back) - * instruction. Note that @size is internally rounded up to be cache - * line size aligned. - */ -static void clean_cache_range(void *addr, size_t size) -{ - u16 x86_clflush_size = boot_cpu_data.x86_clflush_size; - unsigned long clflush_mask = x86_clflush_size - 1; - void *vend = addr + size; - void *p; - - for (p = (void *)((unsigned long)addr & ~clflush_mask); - p < vend; p += x86_clflush_size) - clwb(p); -} - void arch_wb_cache_pmem(void *addr, size_t size) { clean_cache_range(addr, size); diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index ad8a5c586a35..8de029a21e03 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -319,6 +319,36 @@ void clflush_cache_range(void *vaddr, unsigned int size) } EXPORT_SYMBOL_GPL(clflush_cache_range); +static void clean_cache_range_opt(void *vaddr, unsigned int size) +{ + const unsigned long clflush_size = boot_cpu_data.x86_clflush_size; + void *p = (void *)((unsigned long)vaddr & ~(clflush_size - 1)); + void *vend = vaddr + size; + + if (p >= vend) + return; + + for (; p < vend; p += clflush_size) + clwb(p); +} + +/** + * clean_cache_range - write back a cache range with CLWB + * @vaddr: virtual start address + * @size: number of bytes to write back + * + * CLWB (cache line write back) is an unordered instruction which needs fencing + * with MFENCE or SFENCE to avoid ordering issues. Note that @size is + * internally rounded up to be cache line size aligned. + */ +void clean_cache_range(void *vaddr, unsigned int size) +{ + mb(); + clean_cache_range_opt(vaddr, size); + mb(); +} +EXPORT_SYMBOL_GPL(clean_cache_range); + #ifdef CONFIG_ARCH_HAS_PMEM_API void arch_invalidate_pmem(void *addr, size_t size) { From patchwork Thu Oct 7 06:18:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dov Murik X-Patchwork-Id: 12540977 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 E7FAEC4332F for ; Thu, 7 Oct 2021 06:19:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE9D16113E for ; Thu, 7 Oct 2021 06:19:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240223AbhJGGVD (ORCPT ); Thu, 7 Oct 2021 02:21:03 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:37398 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240206AbhJGGVC (ORCPT ); Thu, 7 Oct 2021 02:21:02 -0400 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 19760pg4019114; Thu, 7 Oct 2021 02:18:46 -0400 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=mSMhS5KuMYXSCCHFWTjt0J4W3hRXJ0JBE2fkifaGDT8=; b=S9thM2fBstQ1dV8TTl2IEO1jyhAWp0kv2ctbccncOmHdW/a04TzGzqUwa1QcJxV0/VA3 Tsk9S3cTwCS+4DIb6pwjSwrz0mKsKZvZe3HeUH8BPUmkt9y3oR4F8J/zCDAX86b5LOnD X37DisBTELK7qVVSPjd1W/FIXir43mhoo8vlbpTupqucKAvi4p7TZkv3scwFO/iU2FUA X+J9xp05QGFswKqv43T9StxTgE0HppzpXBMM8CSzISl2C4ORrL7rLUvj/9TYnrJR8V7M GnGAC52lkaV/b/hCvO2pKuhFIw3EZC7ML7Kh/3K6HsclqUK5sPc2IIBi4wziAxHHrvM3 fA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3bhu8j8e7d-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 07 Oct 2021 02:18:45 -0400 Received: from m0098404.ppops.net (m0098404.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 19761QwB024728; Thu, 7 Oct 2021 02:18:45 -0400 Received: from ppma04dal.us.ibm.com (7a.29.35a9.ip4.static.sl-reverse.com [169.53.41.122]) by mx0a-001b2d01.pphosted.com with ESMTP id 3bhu8j8e6y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 07 Oct 2021 02:18:45 -0400 Received: from pps.filterd (ppma04dal.us.ibm.com [127.0.0.1]) by ppma04dal.us.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 1976I7x5031350; Thu, 7 Oct 2021 06:18:44 GMT Received: from b01cxnp23032.gho.pok.ibm.com (b01cxnp23032.gho.pok.ibm.com [9.57.198.27]) by ppma04dal.us.ibm.com with ESMTP id 3bef2cyknu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 07 Oct 2021 06:18:44 +0000 Received: from b01ledav005.gho.pok.ibm.com (b01ledav005.gho.pok.ibm.com [9.57.199.110]) by b01cxnp23032.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 1976IgUm54133066 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 7 Oct 2021 06:18:42 GMT Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F095BAE05F; Thu, 7 Oct 2021 06:18:41 +0000 (GMT) Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8E9F8AE064; Thu, 7 Oct 2021 06:18:41 +0000 (GMT) Received: from amdrome3.watson.ibm.com (unknown [9.2.130.16]) by b01ledav005.gho.pok.ibm.com (Postfix) with ESMTP; Thu, 7 Oct 2021 06:18:41 +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 , "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 v2 2/4] efi/libstub: Copy confidential computing secret area Date: Thu, 7 Oct 2021 06:18:36 +0000 Message-Id: <20211007061838.1381129-3-dovmurik@linux.ibm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211007061838.1381129-1-dovmurik@linux.ibm.com> References: <20211007061838.1381129-1-dovmurik@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: aXPd9KLgSM6987QEM81IlMJW7PW4i6Gx X-Proofpoint-ORIG-GUID: DCueUGmmh6tIu1B6G7fscqprUCAqstzE X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.182.1,Aquarius:18.0.790,Hydra:6.0.391,FMLib:17.0.607.475 definitions=2021-10-06_04,2021-10-07_01,2020-04-07_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 suspectscore=0 mlxlogscore=999 bulkscore=0 lowpriorityscore=0 phishscore=0 spamscore=0 clxscore=1015 priorityscore=1501 impostorscore=0 adultscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2109230001 definitions=main-2110070039 Precedence: bulk List-ID: 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. However, OVMF doesn't force the guest OS to keep this memory area reserved. If EFI exposes such a table entry, efi/libstub will copy this area to a reserved memory for future use inside the kernel. A pointer to the new copy is kept in the EFI table under LINUX_EFI_COCO_SECRET_AREA_GUID. Signed-off-by: Dov Murik --- drivers/firmware/efi/libstub/Makefile | 2 +- drivers/firmware/efi/libstub/coco.c | 68 +++++++++++++++++++++++++ drivers/firmware/efi/libstub/efi-stub.c | 2 + drivers/firmware/efi/libstub/efistub.h | 2 + drivers/firmware/efi/libstub/x86-stub.c | 2 + include/linux/efi.h | 6 +++ 6 files changed, 81 insertions(+), 1 deletion(-) create mode 100644 drivers/firmware/efi/libstub/coco.c diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index d0537573501e..d77690b7dfb9 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -55,7 +55,7 @@ KCOV_INSTRUMENT := n lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o \ file.o mem.o random.o randomalloc.o pci.o \ skip_spaces.o lib-cmdline.o lib-ctype.o \ - alignedmem.o relocate.o vsprintf.o + alignedmem.o relocate.o vsprintf.o coco.o # include the stub's generic dependencies from lib/ when building for ARM/arm64 efi-deps-y := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c diff --git a/drivers/firmware/efi/libstub/coco.c b/drivers/firmware/efi/libstub/coco.c new file mode 100644 index 000000000000..bf546b6a3f72 --- /dev/null +++ b/drivers/firmware/efi/libstub/coco.c @@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Confidential computing (coco) secret area handling + * + * Copyright (C) 2021 IBM Corporation + * Author: Dov Murik + */ + +#include +#include +#include + +#include "efistub.h" + +#define LINUX_EFI_COCO_SECRET_TABLE_GUID \ + EFI_GUID(0xadf956ad, 0xe98c, 0x484c, 0xae, 0x11, 0xb5, 0x1c, 0x7d, 0x33, 0x64, 0x47) + +/** + * struct efi_coco_secret_table - EFI config table that points to the + * confidential computing secret area. The guid + * LINUX_EFI_COCO_SECRET_TABLE_GUID holds this table. + * @base: Physical address of the EFI secret area + * @size: Size (in bytes) of the EFI secret area + */ +struct efi_coco_secret_table { + u64 base; + u64 size; +} __attribute((packed)); + +/* + * Create a copy of EFI's confidential computing secret area (if available) so + * that the secrets are accessible in the kernel after ExitBootServices. + */ +void efi_copy_coco_secret_area(void) +{ + efi_guid_t linux_secret_area_guid = LINUX_EFI_COCO_SECRET_AREA_GUID; + efi_status_t status; + struct efi_coco_secret_table *secret_table; + struct linux_efi_coco_secret_area *secret_area; + + secret_table = get_efi_config_table(LINUX_EFI_COCO_SECRET_TABLE_GUID); + if (!secret_table) + return; + + if (secret_table->size == 0 || secret_table->size >= SZ_4G) + return; + + /* Allocate space for the secret area and copy it */ + status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, + sizeof(*secret_area) + secret_table->size, (void **)&secret_area); + + if (status != EFI_SUCCESS) { + efi_err("Unable to allocate memory for confidential computing secret area copy\n"); + return; + } + + secret_area->size = secret_table->size; + memcpy(secret_area->area, (void *)(unsigned long)secret_table->base, secret_table->size); + + status = efi_bs_call(install_configuration_table, &linux_secret_area_guid, secret_area); + if (status != EFI_SUCCESS) + goto err_free; + + return; + +err_free: + efi_bs_call(free_pool, secret_area); +} diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c index 26e69788f27a..18b3acd15c85 100644 --- a/drivers/firmware/efi/libstub/efi-stub.c +++ b/drivers/firmware/efi/libstub/efi-stub.c @@ -205,6 +205,8 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle, efi_retrieve_tpm2_eventlog(); + efi_copy_coco_secret_area(); + /* Ask the firmware to clear memory on unclean shutdown */ efi_enable_reset_attack_mitigation(); diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index cde0a2ef507d..d604c6744cef 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -858,4 +858,6 @@ efi_enable_reset_attack_mitigation(void) { } void efi_retrieve_tpm2_eventlog(void); +void efi_copy_coco_secret_area(void); + #endif diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c index f14c4ff5839f..4ad85e1b6191 100644 --- a/drivers/firmware/efi/libstub/x86-stub.c +++ b/drivers/firmware/efi/libstub/x86-stub.c @@ -793,6 +793,8 @@ unsigned long efi_main(efi_handle_t handle, efi_retrieve_tpm2_eventlog(); + efi_copy_coco_secret_area(); + setup_graphics(boot_params); setup_efi_pci(boot_params); diff --git a/include/linux/efi.h b/include/linux/efi.h index 6b5d36babfcc..9021dd521302 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(0x940ed1e9, 0xd3da, 0x408b, 0xb3, 0x07, 0xe3, 0x2d, 0x25, 0x4a, 0x65, 0x16) /* OEM GUIDs */ #define DELLEMC_EFI_RCI2_TABLE_GUID EFI_GUID(0x2d9f28a2, 0xa886, 0x456a, 0x97, 0xa8, 0xf1, 0x1e, 0xf2, 0x4f, 0xf4, 0x55) @@ -1282,4 +1283,9 @@ static inline struct efi_mokvar_table_entry *efi_mokvar_entry_find( } #endif +struct linux_efi_coco_secret_area { + u32 size; + u8 area[]; +}; + #endif /* _LINUX_EFI_H */ From patchwork Thu Oct 7 06:18:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dov Murik X-Patchwork-Id: 12540979 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 995AFC4321E for ; Thu, 7 Oct 2021 06:19:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8019461245 for ; Thu, 7 Oct 2021 06:19:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240203AbhJGGVE (ORCPT ); Thu, 7 Oct 2021 02:21:04 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:36662 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231797AbhJGGVC (ORCPT ); Thu, 7 Oct 2021 02:21:02 -0400 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 19766soG026300; 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Thu, 7 Oct 2021 06:18:41 +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 , "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 v2 3/4] efi: Reserve confidential computing secret area Date: Thu, 7 Oct 2021 06:18:37 +0000 Message-Id: <20211007061838.1381129-4-dovmurik@linux.ibm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211007061838.1381129-1-dovmurik@linux.ibm.com> References: <20211007061838.1381129-1-dovmurik@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: hZ96oJHV3vQGjRymjLpIbmcL8kOMJltl X-Proofpoint-ORIG-GUID: n3XjYuVTlvd4cF0KPusrhhj-yEbMPyTd X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.182.1,Aquarius:18.0.790,Hydra:6.0.391,FMLib:17.0.607.475 definitions=2021-10-06_04,2021-10-07_01,2020-04-07_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 spamscore=0 malwarescore=0 suspectscore=0 mlxscore=0 phishscore=0 adultscore=0 clxscore=1015 priorityscore=1501 mlxlogscore=999 lowpriorityscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2109230001 definitions=main-2110070039 Precedence: bulk List-ID: When efi-stub copies an EFI-provided confidential computing (coco) secret area, reserve that memory block for future use within the kernel. Signed-off-by: Dov Murik --- arch/x86/platform/efi/efi.c | 1 + drivers/firmware/efi/Makefile | 2 +- drivers/firmware/efi/coco.c | 41 +++++++++++++++++++++++++++++++++++ drivers/firmware/efi/efi.c | 3 +++ include/linux/efi.h | 3 +++ 5 files changed, 49 insertions(+), 1 deletion(-) create mode 100644 drivers/firmware/efi/coco.c diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 147c30a81f15..35e082e5f603 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -93,6 +93,7 @@ static const unsigned long * const efi_tables[] = { #ifdef CONFIG_LOAD_UEFI_KEYS &efi.mokvar_table, #endif + &efi.coco_secret, }; u64 efi_setup; /* efi setup_data physical address */ diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index c02ff25dd477..bfd35294703e 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -12,7 +12,7 @@ KASAN_SANITIZE_runtime-wrappers.o := n obj-$(CONFIG_ACPI_BGRT) += efi-bgrt.o obj-$(CONFIG_EFI) += efi.o vars.o reboot.o memattr.o tpm.o -obj-$(CONFIG_EFI) += memmap.o +obj-$(CONFIG_EFI) += memmap.o coco.o ifneq ($(CONFIG_EFI_CAPSULE_LOADER),) obj-$(CONFIG_EFI) += capsule.o endif diff --git a/drivers/firmware/efi/coco.c b/drivers/firmware/efi/coco.c new file mode 100644 index 000000000000..42f477d6188c --- /dev/null +++ b/drivers/firmware/efi/coco.c @@ -0,0 +1,41 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Confidential computing (coco) secret area handling + * + * Copyright (C) 2021 IBM Corporation + * Author: Dov Murik + */ + +#define pr_fmt(fmt) "efi: " fmt + +#include +#include +#include +#include + +/* + * Reserve the confidential computing secret area memory + */ +int __init efi_coco_secret_area_reserve(void) +{ + struct linux_efi_coco_secret_area *secret_area; + unsigned long secret_area_size; + + if (efi.coco_secret == EFI_INVALID_TABLE_ADDR) + return 0; + + secret_area = early_memremap(efi.coco_secret, sizeof(*secret_area)); + if (!secret_area) { + pr_err("Failed to map confidential computing secret area\n"); + efi.coco_secret = EFI_INVALID_TABLE_ADDR; + return -ENOMEM; + } + + secret_area_size = sizeof(*secret_area) + secret_area->size; + memblock_reserve(efi.coco_secret, secret_area_size); + + pr_info("Reserved memory of EFI-provided confidential computing secret area"); + + early_memunmap(secret_area, sizeof(*secret_area)); + return 0; +} diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 847f33ffc4ae..07e17ad225a6 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -526,6 +526,7 @@ static const efi_config_table_type_t common_tables[] __initconst = { #ifdef CONFIG_LOAD_UEFI_KEYS {LINUX_EFI_MOK_VARIABLE_TABLE_GUID, &efi.mokvar_table, "MOKvar" }, #endif + {LINUX_EFI_COCO_SECRET_AREA_GUID, &efi.coco_secret, "CocoSecret" }, {}, }; @@ -613,6 +614,8 @@ int __init efi_config_parse_tables(const efi_config_table_t *config_tables, efi_tpm_eventlog_init(); + efi_coco_secret_area_reserve(); + if (mem_reserve != EFI_INVALID_TABLE_ADDR) { unsigned long prsv = mem_reserve; diff --git a/include/linux/efi.h b/include/linux/efi.h index 9021dd521302..e86600af5dfd 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -550,6 +550,7 @@ 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; @@ -1189,6 +1190,8 @@ extern int efi_tpm_final_log_size; extern unsigned long rci2_table_phys; +extern int efi_coco_secret_area_reserve(void); + /* * efi_runtime_service() function identifiers. * "NONE" is used by efi_recover_from_page_fault() to check if the page From patchwork Thu Oct 7 06:18:38 2021 Content-Type: text/plain; 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Thu, 7 Oct 2021 06:18:42 +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 , "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 v2 4/4] virt: Add sev_secret module to expose confidential computing secrets Date: Thu, 7 Oct 2021 06:18:38 +0000 Message-Id: <20211007061838.1381129-5-dovmurik@linux.ibm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211007061838.1381129-1-dovmurik@linux.ibm.com> References: <20211007061838.1381129-1-dovmurik@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: oOheJ8YoSQWwcvHU0B3MBjXJFNTRLnGC X-Proofpoint-GUID: N426yvYS7aM6ZUceUJU6FoCXpVaxsrx2 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.182.1,Aquarius:18.0.790,Hydra:6.0.391,FMLib:17.0.607.475 definitions=2021-10-06_04,2021-10-07_01,2020-04-07_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 lowpriorityscore=0 bulkscore=0 mlxscore=0 malwarescore=0 suspectscore=0 phishscore=0 adultscore=0 mlxlogscore=999 impostorscore=0 spamscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2109230001 definitions=main-2110070039 Precedence: bulk List-ID: The new sev_secret module exposes the confidential computing (coco) secret area via securityfs interface. When the module is loaded (and securityfs is mounted, typically under /sys/kernel/security), a "coco/sev_secret" directory is created in securityfs. In it, a file is created for each secret entry. The name of each such file is the GUID of the secret entry, and its content is the secret data. This allows applications running in a confidential computing setting to read secrets provided by the guest owner via a secure secret injection mechanism (such as AMD SEV's LAUNCH_SECRET command). Removing (unlinking) files in the "coco/sev_secret" directory will zero out the secret in memory, and remove the filesystem entry. If the module is removed and loaded again, that secret will not appear in the filesystem. Signed-off-by: Dov Murik --- .../ABI/testing/securityfs-coco-sev_secret | 49 +++ drivers/virt/Kconfig | 3 + drivers/virt/Makefile | 1 + drivers/virt/coco/sev_secret/Kconfig | 11 + drivers/virt/coco/sev_secret/Makefile | 2 + drivers/virt/coco/sev_secret/sev_secret.c | 320 ++++++++++++++++++ 6 files changed, 386 insertions(+) create mode 100644 Documentation/ABI/testing/securityfs-coco-sev_secret create mode 100644 drivers/virt/coco/sev_secret/Kconfig create mode 100644 drivers/virt/coco/sev_secret/Makefile create mode 100644 drivers/virt/coco/sev_secret/sev_secret.c diff --git a/Documentation/ABI/testing/securityfs-coco-sev_secret b/Documentation/ABI/testing/securityfs-coco-sev_secret new file mode 100644 index 000000000000..3db1a66ff5c4 --- /dev/null +++ b/Documentation/ABI/testing/securityfs-coco-sev_secret @@ -0,0 +1,49 @@ +What: security/coco/sev_secret +Date: October 2021 +Contact: Dov Murik +Description: + Exposes SEV confidential computing (coco) secrets to + userspace via securityfs. + + AMD SEV and SEV-ES allow the Guest Owner to inject secrets + during VM's launch. The secrets are encrypted by the Guest + Owner and decrypted by the AMD-SP (secure processor), and + therefore are not readable by the untrusted host. + + The sev_secret module exposes the secrets to userspace. Each + secret appears as a file under /coco/sev_secret, + where the filename is the GUID of the entry in the secrets + table. + + Two operations are supported for the files: read and unlink. + Reading the file returns the content of secret entry. + Unlinking the file overwrites the secret data with zeroes and + removes the entry from the filesystem. A secret cannot be read + after it has been unlinked. + + For example, listing the available secrets:: + + # modprobe sev_secret + # ls -l /sys/kernel/security/coco/sev_secret + -r--r----- 1 root root 0 Jun 28 11:54 736870e5-84f0-4973-92ec-06879ce3da0b + -r--r----- 1 root root 0 Jun 28 11:54 83c83f7f-1356-4975-8b7e-d3a0b54312c6 + -r--r----- 1 root root 0 Jun 28 11:54 9553f55d-3da2-43ee-ab5d-ff17f78864d2 + -r--r----- 1 root root 0 Jun 28 11:54 e6f5a162-d67f-4750-a67c-5d065f2a9910 + + Reading the secret data by reading a file:: + + # cat /sys/kernel/security/coco/sev_secret/e6f5a162-d67f-4750-a67c-5d065f2a9910 + the-content-of-the-secret-data + + Wiping a secret by unlinking a file:: + + # rm /sys/kernel/security/coco/sev_secret/e6f5a162-d67f-4750-a67c-5d065f2a9910 + # ls -l /sys/kernel/security/coco/sev_secret + -r--r----- 1 root root 0 Jun 28 11:54 736870e5-84f0-4973-92ec-06879ce3da0b + -r--r----- 1 root root 0 Jun 28 11:54 83c83f7f-1356-4975-8b7e-d3a0b54312c6 + -r--r----- 1 root root 0 Jun 28 11:54 9553f55d-3da2-43ee-ab5d-ff17f78864d2 + + Note: The binary format of the secrets table injected by the + Guest Owner is described in + drivers/virt/coco/sev_secret/sev_secret.c under "Structure of + the SEV secret area". diff --git a/drivers/virt/Kconfig b/drivers/virt/Kconfig index 8061e8ef449f..6f73672f593f 100644 --- a/drivers/virt/Kconfig +++ b/drivers/virt/Kconfig @@ -36,4 +36,7 @@ source "drivers/virt/vboxguest/Kconfig" source "drivers/virt/nitro_enclaves/Kconfig" source "drivers/virt/acrn/Kconfig" + +source "drivers/virt/coco/sev_secret/Kconfig" + endif diff --git a/drivers/virt/Makefile b/drivers/virt/Makefile index 3e272ea60cd9..2a7d472478bd 100644 --- a/drivers/virt/Makefile +++ b/drivers/virt/Makefile @@ -8,3 +8,4 @@ obj-y += vboxguest/ obj-$(CONFIG_NITRO_ENCLAVES) += nitro_enclaves/ obj-$(CONFIG_ACRN_HSM) += acrn/ +obj-$(CONFIG_AMD_SEV_SECRET) += coco/sev_secret/ diff --git a/drivers/virt/coco/sev_secret/Kconfig b/drivers/virt/coco/sev_secret/Kconfig new file mode 100644 index 000000000000..76cfb4f405e0 --- /dev/null +++ b/drivers/virt/coco/sev_secret/Kconfig @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0-only +config AMD_SEV_SECRET + tristate "AMD SEV secret area securityfs support" + depends on AMD_MEM_ENCRYPT && EFI + select SECURITYFS + help + This is a driver for accessing the AMD SEV secret area via + securityfs. + + To compile this driver as a module, choose M here. + The module will be called sev_secret. diff --git a/drivers/virt/coco/sev_secret/Makefile b/drivers/virt/coco/sev_secret/Makefile new file mode 100644 index 000000000000..dca0ed3f8f94 --- /dev/null +++ b/drivers/virt/coco/sev_secret/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_AMD_SEV_SECRET) += sev_secret.o diff --git a/drivers/virt/coco/sev_secret/sev_secret.c b/drivers/virt/coco/sev_secret/sev_secret.c new file mode 100644 index 000000000000..3c83aa80f981 --- /dev/null +++ b/drivers/virt/coco/sev_secret/sev_secret.c @@ -0,0 +1,320 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * sev_secret module + * + * Copyright (C) 2021 IBM Corporation + * Author: Dov Murik + */ + +/** + * DOC: sev_secret: Allow reading confidential computing (coco) secret area via + * securityfs interface. + * + * When the module is loaded (and securityfs is mounted, typically under + * /sys/kernel/security), a "coco/sev_secret" directory is created in + * securityfs. In it, a file is created for each secret entry. The name of + * each such file is the GUID of the secret entry, and its content is the + * secret data. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define SEV_SECRET_NUM_FILES 64 + +#define EFI_SEVSECRET_TABLE_HEADER_GUID \ + EFI_GUID(0x1e74f542, 0x71dd, 0x4d66, 0x96, 0x3e, 0xef, 0x42, 0x87, 0xff, 0x17, 0x3b) + +struct sev_secret { + struct dentry *coco_dir; + struct dentry *fs_dir; + struct dentry *fs_files[SEV_SECRET_NUM_FILES]; + struct linux_efi_coco_secret_area *secret_area; +}; + +/* + * Structure of the SEV secret area + * + * Offset Length + * (bytes) (bytes) Usage + * ------- ------- ----- + * 0 16 Secret table header GUID (must be 1e74f542-71dd-4d66-963e-ef4287ff173b) + * 16 4 Length of bytes of the entire secret area + * + * 20 16 First secret entry's GUID + * 36 4 First secret entry's length in bytes (= 16 + 4 + x) + * 40 x First secret entry's data + * + * 40+x 16 Second secret entry's GUID + * 56+x 4 Second secret entry's length in bytes (= 16 + 4 + y) + * 60+x y Second secret entry's data + * + * (... and so on for additional entries) + * + * The GUID of each secret entry designates the usage of the secret data. + */ + +/** + * struct secret_header - Header of entire secret area; this should be followed + * by instances of struct secret_entry. + * @guid: Must be EFI_SEVSECRET_TABLE_HEADER_GUID + * @len: Length in bytes of entire secret area, including header + */ +struct secret_header { + efi_guid_t guid; + u32 len; +} __attribute((packed)); + +/** + * struct secret_entry - Holds one secret entry + * @guid: Secret-specific GUID (or NULL_GUID if this secret entry was deleted) + * @len: Length of secret entry, including its guid and len fields + * @data: The secret data (full of zeros if this secret entry was deleted) + */ +struct secret_entry { + efi_guid_t guid; + u32 len; + u8 data[]; +} __attribute((packed)); + +static size_t secret_entry_data_len(struct secret_entry *e) +{ + return e->len - sizeof(*e); +} + +static struct sev_secret the_sev_secret; + +static inline struct sev_secret *sev_secret_get(void) +{ + return &the_sev_secret; +} + +static int sev_secret_bin_file_show(struct seq_file *file, void *data) +{ + struct secret_entry *e = file->private; + + if (e) + seq_write(file, e->data, secret_entry_data_len(e)); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(sev_secret_bin_file); + +static void wipe_memory(void *addr, size_t size) +{ + memzero_explicit(addr, size); + clean_cache_range(addr, size); +} + +static int sev_secret_unlink(struct inode *dir, struct dentry *dentry) +{ + struct sev_secret *s = sev_secret_get(); + struct inode *inode = d_inode(dentry); + struct secret_entry *e = (struct secret_entry *)inode->i_private; + int i; + + if (e) { + /* Zero out the secret data */ + wipe_memory(e->data, secret_entry_data_len(e)); + e->guid = NULL_GUID; + } + + inode->i_private = NULL; + + for (i = 0; i < SEV_SECRET_NUM_FILES; i++) + if (s->fs_files[i] == dentry) + s->fs_files[i] = NULL; + + /* + * securityfs_remove tries to lock the directory's inode, but we reach + * the unlink callback when it's already locked + */ + inode_unlock(dir); + securityfs_remove(dentry); + inode_lock(dir); + + return 0; +} + +static const struct inode_operations sev_secret_dir_inode_operations = { + .lookup = simple_lookup, + .unlink = sev_secret_unlink, +}; + +static int sev_secret_map_area(void) +{ + struct sev_secret *s = sev_secret_get(); + struct linux_efi_coco_secret_area *secret_area; + u32 secret_area_size; + + if (efi.coco_secret == EFI_INVALID_TABLE_ADDR) { + pr_err("Secret area address is not available\n"); + return -EINVAL; + } + + secret_area = memremap(efi.coco_secret, sizeof(*secret_area), MEMREMAP_WB); + if (secret_area == NULL) { + pr_err("Could not map secret area header\n"); + return -ENOMEM; + } + + secret_area_size = sizeof(*secret_area) + secret_area->size; + memunmap(secret_area); + + secret_area = memremap(efi.coco_secret, secret_area_size, MEMREMAP_WB); + if (secret_area == NULL) { + pr_err("Could not map secret area\n"); + return -ENOMEM; + } + + s->secret_area = secret_area; + return 0; +} + +static void sev_secret_securityfs_teardown(void) +{ + struct sev_secret *s = sev_secret_get(); + int i; + + for (i = (SEV_SECRET_NUM_FILES - 1); i >= 0; i--) { + securityfs_remove(s->fs_files[i]); + s->fs_files[i] = NULL; + } + + securityfs_remove(s->fs_dir); + s->fs_dir = NULL; + + securityfs_remove(s->coco_dir); + s->coco_dir = NULL; + + pr_debug("Removed sev_secret securityfs entries\n"); +} + +static int sev_secret_securityfs_setup(void) +{ + efi_guid_t tableheader_guid = EFI_SEVSECRET_TABLE_HEADER_GUID; + struct sev_secret *s = sev_secret_get(); + int ret = 0, i = 0, bytes_left; + unsigned char *ptr; + struct secret_header *h; + struct secret_entry *e; + struct dentry *dent; + char guid_str[EFI_VARIABLE_GUID_LEN + 1]; + + s->coco_dir = NULL; + s->fs_dir = NULL; + memset(s->fs_files, 0, sizeof(s->fs_files)); + + dent = securityfs_create_dir("coco", NULL); + if (IS_ERR(dent)) { + pr_err("Error creating coco securityfs directory entry err=%ld\n", PTR_ERR(dent)); + return PTR_ERR(dent); + } + s->coco_dir = dent; + + dent = securityfs_create_dir("sev_secret", s->coco_dir); + if (IS_ERR(dent)) { + pr_err("Error creating SEV secret securityfs directory entry err=%ld\n", + PTR_ERR(dent)); + return PTR_ERR(dent); + } + d_inode(dent)->i_op = &sev_secret_dir_inode_operations; + s->fs_dir = dent; + + ptr = s->secret_area->area; + h = (struct secret_header *)ptr; + if (memcmp(&h->guid, &tableheader_guid, sizeof(h->guid))) { + pr_err("SEV secret area does not start with correct GUID\n"); + ret = -EINVAL; + goto err_cleanup; + } + if (h->len < sizeof(*h)) { + pr_err("SEV secret area reported length is too small\n"); + ret = -EINVAL; + goto err_cleanup; + } + + bytes_left = h->len - sizeof(*h); + ptr += sizeof(*h); + while (bytes_left >= (int)sizeof(*e) && i < SEV_SECRET_NUM_FILES) { + e = (struct secret_entry *)ptr; + if (e->len < sizeof(*e) || e->len > (unsigned int)bytes_left) { + pr_err("SEV secret area is corrupted\n"); + ret = -EINVAL; + goto err_cleanup; + } + + /* Skip deleted entries (which will have NULL_GUID) */ + if (efi_guidcmp(e->guid, NULL_GUID)) { + efi_guid_to_str(&e->guid, guid_str); + + dent = securityfs_create_file(guid_str, 0440, s->fs_dir, (void *)e, + &sev_secret_bin_file_fops); + if (IS_ERR(dent)) { + pr_err("Error creating SEV secret securityfs entry\n"); + ret = PTR_ERR(dent); + goto err_cleanup; + } + + s->fs_files[i++] = dent; + } + ptr += e->len; + bytes_left -= e->len; + } + + pr_debug("Created %d entries in sev_secret securityfs\n", i); + return 0; + +err_cleanup: + sev_secret_securityfs_teardown(); + return ret; +} + +static void sev_secret_unmap_area(void) +{ + struct sev_secret *s = sev_secret_get(); + + if (s->secret_area) { + memunmap(s->secret_area); + s->secret_area = NULL; + } +} + +static int __init sev_secret_init(void) +{ + int ret; + + ret = sev_secret_map_area(); + if (ret) + return ret; + + ret = sev_secret_securityfs_setup(); + if (ret) + goto err_unmap; + + return ret; + +err_unmap: + sev_secret_unmap_area(); + return ret; +} + +static void __exit sev_secret_exit(void) +{ + sev_secret_securityfs_teardown(); + sev_secret_unmap_area(); +} + +module_init(sev_secret_init); +module_exit(sev_secret_exit); + +MODULE_DESCRIPTION("AMD SEV confidential computing secret area access"); +MODULE_AUTHOR("IBM"); +MODULE_LICENSE("GPL");