From patchwork Wed Mar 20 16:21:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 10862175 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A7F591708 for ; Wed, 20 Mar 2019 16:24:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 87A6828807 for ; Wed, 20 Mar 2019 16:24:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7B1542891A; Wed, 20 Mar 2019 16:24:20 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9DEC62888D for ; Wed, 20 Mar 2019 16:24:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726860AbfCTQYT (ORCPT ); Wed, 20 Mar 2019 12:24:19 -0400 Received: from mga18.intel.com ([134.134.136.126]:42019 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726295AbfCTQYT (ORCPT ); Wed, 20 Mar 2019 12:24:19 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Mar 2019 09:23:47 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,249,1549958400"; d="scan'208";a="135715117" Received: from sorenthe-mobl1.ger.corp.intel.com (HELO localhost) ([10.249.254.203]) by orsmga003.jf.intel.com with ESMTP; 20 Mar 2019 09:23:37 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, serge.ayoun@intel.com, shay.katz-zamir@intel.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, Jarkko Sakkinen , Suresh Siddha Subject: [PATCH v19,RESEND 12/27] x86/sgx: Enumerate and track EPC sections Date: Wed, 20 Mar 2019 18:21:04 +0200 Message-Id: <20190320162119.4469-13-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190320162119.4469-1-jarkko.sakkinen@linux.intel.com> References: <20190320162119.4469-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Sean Christopherson Enumerate Enclave Page Cache (EPC) sections via CPUID and add the data structures necessary to track EPC pages so that they can be allocated, freed and managed. As a system may have multiple EPC sections, invoke CPUID on SGX sub-leafs until an invalid leaf is encountered. On NUMA systems, a node can have at most one bank. A bank can be at most part of two nodes. SGX supports both nodes with a single memory controller and also sub-cluster nodes with severals memory controllers on a single die. For simplicity, support a maximum of eight EPC sections. Current client hardware supports only a single section, while upcoming server hardware will support at most eight sections. Bounding the number of sections also allows the section ID to be embedded along with a page's offset in a single unsigned long, enabling easy retrieval of both the VA and PA for a given page. Signed-off-by: Sean Christopherson Co-developed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Co-developed-by: Suresh Siddha Signed-off-by: Suresh Siddha Co-developed-by: Serge Ayoun Signed-off-by: Serge Ayoun --- arch/x86/Kconfig | 19 ++++ arch/x86/kernel/cpu/Makefile | 1 + arch/x86/kernel/cpu/sgx/Makefile | 1 + arch/x86/kernel/cpu/sgx/main.c | 149 +++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 62 +++++++++++++ 5 files changed, 232 insertions(+) create mode 100644 arch/x86/kernel/cpu/sgx/Makefile create mode 100644 arch/x86/kernel/cpu/sgx/main.c create mode 100644 arch/x86/kernel/cpu/sgx/sgx.h diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index c1f9b3cf437c..dc630208003f 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1921,6 +1921,25 @@ config X86_INTEL_MEMORY_PROTECTION_KEYS If unsure, say y. +config INTEL_SGX + bool "Intel SGX core functionality" + depends on X86_64 && CPU_SUP_INTEL + help + + Intel(R) SGX is a set of CPU instructions that can be used by + applications to set aside private regions of code and data. The code + outside the enclave is disallowed to access the memory inside the + enclave by the CPU access control. + + The firmware uses PRMRR registers to reserve an area of physical memory + called Enclave Page Cache (EPC). There is a hardware unit in the + processor called Memory Encryption Engine. The MEE encrypts and decrypts + the EPC pages as they enter and leave the processor package. + + For details, see Documentation/x86/intel_sgx.rst + + If unsure, say N. + config EFI bool "EFI runtime service support" depends on ACPI diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile index cfd24f9f7614..d1163c0fd5d6 100644 --- a/arch/x86/kernel/cpu/Makefile +++ b/arch/x86/kernel/cpu/Makefile @@ -40,6 +40,7 @@ obj-$(CONFIG_X86_MCE) += mce/ obj-$(CONFIG_MTRR) += mtrr/ obj-$(CONFIG_MICROCODE) += microcode/ obj-$(CONFIG_X86_CPU_RESCTRL) += resctrl/ +obj-$(CONFIG_INTEL_SGX) += sgx/ obj-$(CONFIG_X86_LOCAL_APIC) += perfctr-watchdog.o diff --git a/arch/x86/kernel/cpu/sgx/Makefile b/arch/x86/kernel/cpu/sgx/Makefile new file mode 100644 index 000000000000..b666967fd570 --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/Makefile @@ -0,0 +1 @@ +obj-y += main.o diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c new file mode 100644 index 000000000000..18ce4acdd7ef --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) +// Copyright(c) 2016-17 Intel Corporation. + +#include +#include +#include +#include +#include +#include +#include +#include "arch.h" +#include "sgx.h" + +struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS]; +EXPORT_SYMBOL_GPL(sgx_epc_sections); + +static int sgx_nr_epc_sections; + +static void sgx_section_put_page(struct sgx_epc_section *section, + struct sgx_epc_page *page) +{ + list_add_tail(&page->list, §ion->page_list); + section->free_cnt++; +} + +static __init void sgx_free_epc_section(struct sgx_epc_section *section) +{ + struct sgx_epc_page *page; + + while (!list_empty(§ion->page_list)) { + page = list_first_entry(§ion->page_list, + struct sgx_epc_page, list); + list_del(&page->list); + kfree(page); + } + memunmap(section->va); +} + +static __init int sgx_init_epc_section(u64 addr, u64 size, unsigned long index, + struct sgx_epc_section *section) +{ + unsigned long nr_pages = size >> PAGE_SHIFT; + struct sgx_epc_page *page; + unsigned long i; + + section->va = memremap(addr, size, MEMREMAP_WB); + if (!section->va) + return -ENOMEM; + + section->pa = addr; + spin_lock_init(§ion->lock); + INIT_LIST_HEAD(§ion->page_list); + + for (i = 0; i < nr_pages; i++) { + page = kzalloc(sizeof(*page), GFP_KERNEL); + if (!page) + goto out; + page->desc = (addr + (i << PAGE_SHIFT)) | index; + sgx_section_put_page(section, page); + } + + return 0; +out: + sgx_free_epc_section(section); + return -ENOMEM; +} + +static __init void sgx_page_cache_teardown(void) +{ + int i; + + for (i = 0; i < sgx_nr_epc_sections; i++) + sgx_free_epc_section(&sgx_epc_sections[i]); +} + +/** + * A section metric is concatenated in a way that @low bits 12-31 define the + * bits 12-31 of the metric and @high bits 0-19 define the bits 32-51 of the + * metric. + */ +static inline u64 sgx_calc_section_metric(u64 low, u64 high) +{ + return (low & GENMASK_ULL(31, 12)) + + ((high & GENMASK_ULL(19, 0)) << 32); +} + +static __init int sgx_page_cache_init(void) +{ + u32 eax, ebx, ecx, edx, type; + u64 pa, size; + int ret; + int i; + + BUILD_BUG_ON(SGX_MAX_EPC_SECTIONS > (SGX_EPC_SECTION_MASK + 1)); + + for (i = 0; i < (SGX_MAX_EPC_SECTIONS + 1); i++) { + cpuid_count(SGX_CPUID, i + SGX_CPUID_FIRST_VARIABLE_SUB_LEAF, + &eax, &ebx, &ecx, &edx); + + type = eax & SGX_CPUID_SUB_LEAF_TYPE_MASK; + if (type == SGX_CPUID_SUB_LEAF_INVALID) + break; + if (type != SGX_CPUID_SUB_LEAF_EPC_SECTION) { + pr_err_once("sgx: Unknown sub-leaf type: %u\n", type); + return -ENODEV; + } + if (i == SGX_MAX_EPC_SECTIONS) { + pr_warn("sgx: More than " + __stringify(SGX_MAX_EPC_SECTIONS) + " EPC sections\n"); + break; + } + + pa = sgx_calc_section_metric(eax, ebx); + size = sgx_calc_section_metric(ecx, edx); + pr_info("sgx: EPC section 0x%llx-0x%llx\n", pa, pa + size - 1); + + ret = sgx_init_epc_section(pa, size, i, &sgx_epc_sections[i]); + if (ret) { + sgx_page_cache_teardown(); + return ret; + } + + sgx_nr_epc_sections++; + } + + if (!sgx_nr_epc_sections) { + pr_err("sgx: There are zero EPC sections.\n"); + return -ENODEV; + } + + return 0; +} + +static __init int sgx_init(void) +{ + int ret; + + if (!boot_cpu_has(X86_FEATURE_SGX)) + return false; + + ret = sgx_page_cache_init(); + if (ret) + return ret; + + return 0; +} + +arch_initcall(sgx_init); diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h new file mode 100644 index 000000000000..228e3dae360d --- /dev/null +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */ +#ifndef _X86_SGX_H +#define _X86_SGX_H + +#include +#include +#include +#include +#include +#include +#include + +struct sgx_epc_page { + unsigned long desc; + struct list_head list; +}; + +/** + * struct sgx_epc_section + * + * The firmware can define multiple chunks of EPC to the different areas of the + * physical memory e.g. for memory areas of the each node. This structure is + * used to store EPC pages for one EPC section and virtual memory area where + * the pages have been mapped. + */ +struct sgx_epc_section { + unsigned long pa; + void *va; + struct list_head page_list; + unsigned long free_cnt; + spinlock_t lock; +}; + +#define SGX_MAX_EPC_SECTIONS 8 + +extern struct sgx_epc_section sgx_epc_sections[SGX_MAX_EPC_SECTIONS]; + +/** + * enum sgx_epc_page_desc - bits and masks for an EPC page's descriptor + * %SGX_EPC_SECTION_MASK: SGX allows to have multiple EPC sections in the + * physical memory. The existing and near-future + * hardware defines at most eight sections, hence + * three bits to hold a section. + */ +enum sgx_epc_page_desc { + SGX_EPC_SECTION_MASK = GENMASK_ULL(3, 0), + /* bits 12-63 are reserved for the physical page address of the page */ +}; + +static inline struct sgx_epc_section *sgx_epc_section(struct sgx_epc_page *page) +{ + return &sgx_epc_sections[page->desc & SGX_EPC_SECTION_MASK]; +} + +static inline void *sgx_epc_addr(struct sgx_epc_page *page) +{ + struct sgx_epc_section *section = sgx_epc_section(page); + + return section->va + (page->desc & PAGE_MASK) - section->pa; +} + +#endif /* _X86_SGX_H */