[PATCH v22 06/24] x86/sgx: Add SGX microarchitectural data structures
From: Jarkko Sakkinen
Date: Tue Sep 03 2019 - 10:28:03 EST
Define the SGX microarchitectural data structures used by various SGX
opcodes. This is not an exhaustive representation of all SGX data
structures but only those needed by the kernel.
[1] Intel SDM: 37.6 INTELÂ SGX DATA STRUCTURES OVERVIEW
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Co-developed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/kernel/cpu/sgx/arch.h | 423 +++++++++++++++++++++++++++++++++
1 file changed, 423 insertions(+)
create mode 100644 arch/x86/kernel/cpu/sgx/arch.h
diff --git a/arch/x86/kernel/cpu/sgx/arch.h b/arch/x86/kernel/cpu/sgx/arch.h
new file mode 100644
index 000000000000..725a47f9f761
--- /dev/null
+++ b/arch/x86/kernel/cpu/sgx/arch.h
@@ -0,0 +1,423 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/**
+ * Copyright(c) 2016-18 Intel Corporation.
+ *
+ * Contains data structures defined by the SGX architecture. Data structures
+ * defined by the Linux software stack should not be placed here.
+ */
+#ifndef _ASM_X86_SGX_ARCH_H
+#define _ASM_X86_SGX_ARCH_H
+
+#include <linux/types.h>
+
+#define SGX_CPUID 0x12
+#define SGX_CPUID_FIRST_VARIABLE_SUB_LEAF 2
+
+/**
+ * enum sgx_sub_leaf_types - SGX CPUID variable sub-leaf types
+ * %SGX_CPUID_SUB_LEAF_INVALID: Indicates this sub-leaf is invalid.
+ * %SGX_CPUID_SUB_LEAF_EPC_SECTION: Sub-leaf enumerates an EPC section.
+ */
+enum sgx_sub_leaf_types {
+ SGX_CPUID_SUB_LEAF_INVALID = 0x0,
+ SGX_CPUID_SUB_LEAF_EPC_SECTION = 0x1,
+};
+
+#define SGX_CPUID_SUB_LEAF_TYPE_MASK GENMASK(3, 0)
+
+/**
+ * enum sgx_encls_leaves - ENCLS leaf functions
+ * %SGX_ECREATE: Create an enclave.
+ * %SGX_EADD: Add a page to an uninitialized enclave.
+ * %SGX_EINIT: Initialize an enclave, i.e. launch an enclave.
+ * %SGX_EREMOVE: Remove a page from an enclave.
+ * %SGX_EDBGRD: Read a word from an enclve (peek).
+ * %SGX_EDBGWR: Write a word to an enclave (poke).
+ * %SGX_EEXTEND: Measure 256 bytes of an added enclave page.
+ * %SGX_ELDB: Load a swapped page in blocked state.
+ * %SGX_ELDU: Load a swapped page in unblocked state.
+ * %SGX_EBLOCK: Change page state to blocked i.e. entering hardware
+ * threads cannot access it and create new TLB entries.
+ * %SGX_EPA: Create a Version Array (VA) page used to store isvsvn
+ * number for a swapped EPC page.
+ * %SGX_EWB: Swap an enclave page to the regular memory. Checks that
+ * all threads have exited that were in the previous
+ * shoot-down sequence.
+ * %SGX_ETRACK: Start a new shoot down sequence. Used to together with
+ * EBLOCK to make sure that a page is safe to swap.
+ * %SGX_EAUG: Add a page to an initialized enclave.
+ * %SGX_EMODPR: Restrict an EPC page's permissions.
+ * %SGX_EMODT: Modify the page type of an EPC page.
+ */
+enum sgx_encls_leaves {
+ SGX_ECREATE = 0x00,
+ SGX_EADD = 0x01,
+ SGX_EINIT = 0x02,
+ SGX_EREMOVE = 0x03,
+ SGX_EDGBRD = 0x04,
+ SGX_EDGBWR = 0x05,
+ SGX_EEXTEND = 0x06,
+ SGX_ELDB = 0x07,
+ SGX_ELDU = 0x08,
+ SGX_EBLOCK = 0x09,
+ SGX_EPA = 0x0A,
+ SGX_EWB = 0x0B,
+ SGX_ETRACK = 0x0C,
+ SGX_EAUG = 0x0D,
+ SGX_EMODPR = 0x0E,
+ SGX_EMODT = 0x0F,
+};
+
+#define SGX_MODULUS_SIZE 384
+
+/**
+ * enum sgx_miscselect - additional information to an SSA frame
+ * %SGX_MISC_EXINFO: Report #PF or #GP to the SSA frame.
+ *
+ * Save State Area (SSA) is a stack inside the enclave used to store processor
+ * state when an exception or interrupt occurs. This enum defines additional
+ * information stored to an SSA frame.
+ */
+enum sgx_miscselect {
+ SGX_MISC_EXINFO = BIT(0),
+};
+
+#define SGX_MISC_RESERVED_MASK GENMASK_ULL(63, 1)
+
+#define SGX_SSA_GPRS_SIZE 182
+#define SGX_SSA_MISC_EXINFO_SIZE 16
+
+/**
+ * enum sgx_attributes - the attributes field in &struct sgx_secs
+ * %SGX_ATTR_INIT: Enclave can be entered (is initialized).
+ * %SGX_ATTR_DEBUG: Allow ENCLS(EDBGRD) and ENCLS(EDBGWR).
+ * %SGX_ATTR_MODE64BIT: Tell that this a 64-bit enclave.
+ * %SGX_ATTR_PROVISIONKEY: Allow to use provisioning keys for remote
+ * attestation.
+ * %SGX_ATTR_KSS: Allow to use key separation and sharing (KSS).
+ * %SGX_ATTR_EINITTOKENKEY: Allow to use token signing key that is used to
+ * sign cryptographic tokens that can be passed to
+ * EINIT as an authorization to run an enclave.
+ */
+enum sgx_attribute {
+ SGX_ATTR_INIT = BIT(0),
+ SGX_ATTR_DEBUG = BIT(1),
+ SGX_ATTR_MODE64BIT = BIT(2),
+ SGX_ATTR_PROVISIONKEY = BIT(4),
+ SGX_ATTR_EINITTOKENKEY = BIT(5),
+ SGX_ATTR_KSS = BIT(7),
+};
+
+#define SGX_ATTR_RESERVED_MASK (BIT_ULL(3) | BIT_ULL(7) | GENMASK_ULL(63, 8))
+#define SGX_ATTR_ALLOWED_MASK (SGX_ATTR_DEBUG | SGX_ATTR_MODE64BIT | \
+ SGX_ATTR_KSS)
+#define SGX_SECS_RESERVED1_SIZE 24
+#define SGX_SECS_RESERVED2_SIZE 32
+#define SGX_SECS_RESERVED3_SIZE 96
+#define SGX_SECS_RESERVED4_SIZE 3836
+
+/**
+ * struct sgx_secs - SGX Enclave Control Structure (SECS)
+ * @size: size of the address space
+ * @base: base address of the address space
+ * @ssa_frame_size: size of an SSA frame
+ * @miscselect: additional information stored to an SSA frame
+ * @attributes: attributes for enclave
+ * @xfrm: XSave-Feature Request Mask (subset of XCR0)
+ * @mrenclave: SHA256-hash of the enclave contents
+ * @mrsigner: SHA256-hash of the public key used to sign the SIGSTRUCT
+ * @isvprodid: a user-defined value that is used in key derivation
+ * @isvsvn: a user-defined value that is used in key derivation
+ *
+ * SGX Enclave Control Structure (SECS) is a special enclave page that is not
+ * visible in the address space. In fact, this structure defines the address
+ * range and other global attributes for the enclave and it is the first EPC
+ * page created for any enclave. It is moved from a temporary buffer to an EPC
+ * by the means of ENCLS(ECREATE) leaf.
+ */
+struct sgx_secs {
+ u64 size;
+ u64 base;
+ u32 ssa_frame_size;
+ u32 miscselect;
+ u8 reserved1[SGX_SECS_RESERVED1_SIZE];
+ u64 attributes;
+ u64 xfrm;
+ u32 mrenclave[8];
+ u8 reserved2[SGX_SECS_RESERVED2_SIZE];
+ u32 mrsigner[8];
+ u8 reserved3[SGX_SECS_RESERVED3_SIZE];
+ u16 isvprodid;
+ u16 isvsvn;
+ u8 reserved4[SGX_SECS_RESERVED4_SIZE];
+} __packed;
+
+/**
+ * enum sgx_tcs_flags - execution flags for TCS
+ * %SGX_TCS_DBGOPTIN: If enabled allows single-stepping and breakpoints
+ * inside an enclave. It is cleared by EADD but can
+ * be set later with EDBGWR.
+ */
+enum sgx_tcs_flags {
+ SGX_TCS_DBGOPTIN = 0x01,
+};
+
+#define SGX_TCS_RESERVED_MASK GENMASK_ULL(63, 1)
+#define SGX_TCS_RESERVED_SIZE 4024
+
+/**
+ * struct sgx_tcs - Thread Control Structure (TCS)
+ * @state: used to mark an entered TCS
+ * @flags: execution flags (cleared by EADD)
+ * @ssa_offset: SSA stack offset relative to the enclave base
+ * @ssa_index: the current SSA frame index (cleard by EADD)
+ * @nr_ssa_frames: the number of frame in the SSA stack
+ * @entry_offset: entry point offset relative to the enclave base
+ * @exit_addr: address outside the enclave to exit on an exception or
+ * interrupt
+ * @fs_offset: offset relative to the enclave base to become FS
+ * segment inside the enclave
+ * @gs_offset: offset relative to the enclave base to become GS
+ * segment inside the enclave
+ * @fs_limit: size to become a new FS-limit (only 32-bit enclaves)
+ * @gs_limit: size to become a new GS-limit (only 32-bit enclaves)
+ *
+ * Thread Control Structure (TCS) is an enclave page visible in its address
+ * space that defines an entry point inside the enclave. A thread enters inside
+ * an enclave by supplying address of TCS to ENCLU(EENTER). A TCS can be entered
+ * by only one thread at a time.
+ */
+struct sgx_tcs {
+ u64 state;
+ u64 flags;
+ u64 ssa_offset;
+ u32 ssa_index;
+ u32 nr_ssa_frames;
+ u64 entry_offset;
+ u64 exit_addr;
+ u64 fs_offset;
+ u64 gs_offset;
+ u32 fs_limit;
+ u32 gs_limit;
+ u8 reserved[SGX_TCS_RESERVED_SIZE];
+} __packed;
+
+/**
+ * struct sgx_pageinfo - an enclave page descriptor
+ * @addr: address of the enclave page
+ * @contents: pointer to the page contents
+ * @metadata: pointer either to a SECINFO or PCMD instance
+ * @secs: address of the SECS page
+ */
+struct sgx_pageinfo {
+ u64 addr;
+ u64 contents;
+ u64 metadata;
+ u64 secs;
+} __packed __aligned(32);
+
+
+/**
+ * enum sgx_page_type - bits in the SECINFO flags defining the page type
+ * %SGX_PAGE_TYPE_SECS: a SECS page
+ * %SGX_PAGE_TYPE_TCS: a TCS page
+ * %SGX_PAGE_TYPE_REG: a regular page
+ * %SGX_PAGE_TYPE_VA: a VA page
+ * %SGX_PAGE_TYPE_TRIM: a page in trimmed state
+ */
+enum sgx_page_type {
+ SGX_PAGE_TYPE_SECS,
+ SGX_PAGE_TYPE_TCS,
+ SGX_PAGE_TYPE_REG,
+ SGX_PAGE_TYPE_VA,
+ SGX_PAGE_TYPE_TRIM,
+};
+
+#define SGX_NR_PAGE_TYPES 5
+#define SGX_PAGE_TYPE_MASK GENMASK(7, 0)
+
+/**
+ * enum sgx_secinfo_flags - the flags field in &struct sgx_secinfo
+ * %SGX_SECINFO_R: allow read
+ * %SGX_SECINFO_W: allow write
+ * %SGX_SECINFO_X: allow execution
+ * %SGX_SECINFO_SECS: a SECS page
+ * %SGX_SECINFO_TCS: a TCS page
+ * %SGX_SECINFO_REG: a regular page
+ * %SGX_SECINFO_VA: a VA page
+ * %SGX_SECINFO_TRIM: a page in trimmed state
+ */
+enum sgx_secinfo_flags {
+ SGX_SECINFO_R = BIT(0),
+ SGX_SECINFO_W = BIT(1),
+ SGX_SECINFO_X = BIT(2),
+ SGX_SECINFO_SECS = (SGX_PAGE_TYPE_SECS << 8),
+ SGX_SECINFO_TCS = (SGX_PAGE_TYPE_TCS << 8),
+ SGX_SECINFO_REG = (SGX_PAGE_TYPE_REG << 8),
+ SGX_SECINFO_VA = (SGX_PAGE_TYPE_VA << 8),
+ SGX_SECINFO_TRIM = (SGX_PAGE_TYPE_TRIM << 8),
+};
+
+#define SGX_SECINFO_PERMISSION_MASK GENMASK_ULL(2, 0)
+#define SGX_SECINFO_PAGE_TYPE_MASK (SGX_PAGE_TYPE_MASK << 8)
+#define SGX_SECINFO_RESERVED_MASK ~(SGX_SECINFO_PERMISSION_MASK | \
+ SGX_SECINFO_PAGE_TYPE_MASK)
+
+/**
+ * struct sgx_secinfo - describes attributes of an EPC page
+ * @flags: permissions and type
+ *
+ * Used together with ENCLS leaves that add or modify an EPC page to an
+ * enclave to define page permissions and type.
+ */
+struct sgx_secinfo {
+ u64 flags;
+ u8 reserved[56];
+} __packed __aligned(64);
+
+#define SGX_PCMD_RESERVED_SIZE 40
+
+/**
+ * struct sgx_pcmd - Paging Crypto Metadata (PCMD)
+ * @enclave_id: enclave identifier
+ * @mac: MAC over PCMD, page contents and isvsvn
+ *
+ * PCMD is stored for every swapped page to the regular memory. When ELDU loads
+ * the page back it recalculates the MAC by using a isvsvn number stored in a
+ * VA page. Together these two structures bring integrity and rollback
+ * protection.
+ */
+struct sgx_pcmd {
+ struct sgx_secinfo secinfo;
+ u64 enclave_id;
+ u8 reserved[SGX_PCMD_RESERVED_SIZE];
+ u8 mac[16];
+} __packed __aligned(128);
+
+#define SGX_SIGSTRUCT_RESERVED1_SIZE 84
+#define SGX_SIGSTRUCT_RESERVED2_SIZE 20
+#define SGX_SIGSTRUCT_RESERVED3_SIZE 32
+#define SGX_SIGSTRUCT_RESERVED4_SIZE 12
+
+/**
+ * struct sgx_sigstruct_header - defines author of the enclave
+ * @header1: constant byte string
+ * @vendor: must be either 0x0000 or 0x8086
+ * @date: YYYYMMDD in BCD
+ * @header2: costant byte string
+ * @swdefined: software defined value
+ */
+struct sgx_sigstruct_header {
+ u64 header1[2];
+ u32 vendor;
+ u32 date;
+ u64 header2[2];
+ u32 swdefined;
+ u8 reserved1[84];
+} __packed;
+
+/**
+ * struct sgx_sigstruct_body - defines contents of the enclave
+ * @miscselect: additional information stored to an SSA frame
+ * @misc_mask: required miscselect in SECS
+ * @attributes: attributes for enclave
+ * @xfrm: XSave-Feature Request Mask (subset of XCR0)
+ * @attributes_mask: required attributes in SECS
+ * @xfrm_mask: required XFRM in SECS
+ * @mrenclave: SHA256-hash of the enclave contents
+ * @isvprodid: a user-defined value that is used in key derivation
+ * @isvsvn: a user-defined value that is used in key derivation
+ */
+struct sgx_sigstruct_body {
+ u32 miscselect;
+ u32 misc_mask;
+ u8 reserved2[20];
+ u64 attributes;
+ u64 xfrm;
+ u64 attributes_mask;
+ u64 xfrm_mask;
+ u8 mrenclave[32];
+ u8 reserved3[32];
+ u16 isvprodid;
+ u16 isvsvn;
+} __packed;
+
+/**
+ * struct sgx_sigstruct - an enclave signature
+ * @header: defines author of the enclave
+ * @modulus: the modulus of the public key
+ * @exponent: the exponent of the public key
+ * @signature: the signature calculated over the fields except modulus,
+ * @body: defines contents of the enclave
+ * @q1: a value used in RSA signature verification
+ * @q2: a value used in RSA signature verification
+ *
+ * Header and body are the parts that are actual signed. The remaining fields
+ * define the signature of the enclave.
+ */
+struct sgx_sigstruct {
+ struct sgx_sigstruct_header header;
+ u8 modulus[SGX_MODULUS_SIZE];
+ u32 exponent;
+ u8 signature[SGX_MODULUS_SIZE];
+ struct sgx_sigstruct_body body;
+ u8 reserved4[12];
+ u8 q1[SGX_MODULUS_SIZE];
+ u8 q2[SGX_MODULUS_SIZE];
+} __packed;
+
+#define SGX_EINITTOKEN_RESERVED1_SIZE 11
+#define SGX_EINITTOKEN_RESERVED2_SIZE 32
+#define SGX_EINITTOKEN_RESERVED3_SIZE 32
+#define SGX_EINITTOKEN_RESERVED4_SIZE 24
+
+/**
+ * struct sgx_einittoken - a token permitting to launch an enclave
+ * @valid: one if valid and zero if invalid
+ * @attributes: attributes for enclave
+ * @xfrm: XSave-Feature Request Mask (subset of XCR0)
+ * @mrenclave: SHA256-hash of the enclave contents
+ * @mrsigner: SHA256-hash of the public key used to sign the
+ * SIGSTRUCT
+ * @le_cpusvn: a value that reflects the SGX implementation
+ * running in in the CPU
+ * @le_isvprodid: a user-defined value that is used in key
+ * derivation
+ * @le_isvsvn: a user-defined value that is used in key
+ * derivation
+ * @le_keyed_miscselect: LE's miscselect masked with the token keys
+ * miscselect
+ * @le_keyed_attributes: LE's attributes masked with the token keys
+ * attributes
+ * @le_keyed_xfrm: LE's XFRM masked with the token keys xfrm
+ * @salt: random salt for wear-out protection
+ * @mac: CMAC over the preceding fields
+ *
+ * An enclave with EINITTOKENKEY attribute can access a key with the same name
+ * by using ENCLS(EGETKEY) and use this to sign cryptographic tokens that can
+ * be passed to ENCLS(EINIT) to permit the launch of other enclaves. This is
+ * the only viable way to launch enclaves if IA32_SGXLEPUBKEYHASHn MSRs are
+ * locked assuming that there is a Launch Enclave (LE) available that can be
+ * used for generating these tokens.
+ */
+struct sgx_einittoken {
+ u32 valid;
+ u32 reserved1[SGX_EINITTOKEN_RESERVED1_SIZE];
+ u64 attributes;
+ u64 xfrm;
+ u8 mrenclave[32];
+ u8 reserved2[SGX_EINITTOKEN_RESERVED2_SIZE];
+ u8 mrsigner[32];
+ u8 reserved3[SGX_EINITTOKEN_RESERVED3_SIZE];
+ u8 le_cpusvn[16];
+ u16 le_isvprodid;
+ u16 le_isvsvn;
+ u8 reserved4[SGX_EINITTOKEN_RESERVED4_SIZE];
+ u32 le_keyed_miscselect;
+ u64 le_keyed_attributes;
+ u64 le_keyed_xfrm;
+ u8 salt[32];
+ u8 mac[16];
+} __packed __aligned(512);
+
+#endif /* _ASM_X86_SGX_ARCH_H */
--
2.20.1