root/arch/x86/include/asm/sgx.h
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright(c) 2016-20 Intel Corporation.
 *
 * Intel Software Guard Extensions (SGX) support.
 */
#ifndef _ASM_X86_SGX_H
#define _ASM_X86_SGX_H

#include <linux/bits.h>
#include <linux/types.h>

/*
 * This file contains both data structures defined by SGX architecture and Linux
 * defined software data structures and functions.  The two should not be mixed
 * together for better readability.  The architectural definitions come first.
 */

/* The SGX specific CPUID function. */
#define SGX_CPUID               0x12
/* EPC enumeration. */
#define SGX_CPUID_EPC           2
/* An invalid EPC section, i.e. the end marker. */
#define SGX_CPUID_EPC_INVALID   0x0
/* A valid EPC section. */
#define SGX_CPUID_EPC_SECTION   0x1
/* The bitmask for the EPC section type. */
#define SGX_CPUID_EPC_MASK      GENMASK(3, 0)

enum sgx_encls_function {
        ECREATE         = 0x00,
        EADD            = 0x01,
        EINIT           = 0x02,
        EREMOVE         = 0x03,
        EDGBRD          = 0x04,
        EDGBWR          = 0x05,
        EEXTEND         = 0x06,
        ELDU            = 0x08,
        EBLOCK          = 0x09,
        EPA             = 0x0A,
        EWB             = 0x0B,
        ETRACK          = 0x0C,
        EAUG            = 0x0D,
        EMODPR          = 0x0E,
        EMODT           = 0x0F,
        EUPDATESVN      = 0x18,
};

/**
 * SGX_ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr
 *
 * ENCLS has its own (positive value) error codes and also generates
 * ENCLS specific #GP and #PF faults.  And the ENCLS values get munged
 * with system error codes as everything percolates back up the stack.
 * Unfortunately (for us), we need to precisely identify each unique
 * error code, e.g. the action taken if EWB fails varies based on the
 * type of fault and on the exact SGX error code, i.e. we can't simply
 * convert all faults to -EFAULT.
 *
 * To make all three error types coexist, we set bit 30 to identify an
 * ENCLS fault.  Bit 31 (technically bits N:31) is used to differentiate
 * between positive (faults and SGX error codes) and negative (system
 * error codes) values.
 */
#define SGX_ENCLS_FAULT_FLAG 0x40000000

/**
 * enum sgx_return_code - The return code type for ENCLS, ENCLU and ENCLV
 * @SGX_EPC_PAGE_CONFLICT:      Page is being written by other ENCLS function.
 * @SGX_NOT_TRACKED:            Previous ETRACK's shootdown sequence has not
 *                              been completed yet.
 * @SGX_CHILD_PRESENT:          SECS has child pages present in the EPC.
 * @SGX_INVALID_EINITTOKEN:     EINITTOKEN is invalid and enclave signer's
 *                              public key does not match IA32_SGXLEPUBKEYHASH.
 * @SGX_PAGE_NOT_MODIFIABLE:    The EPC page cannot be modified because it
 *                              is in the PENDING or MODIFIED state.
 * @SGX_INSUFFICIENT_ENTROPY:   Insufficient entropy in RNG.
 * @SGX_NO_UPDATE:              EUPDATESVN could not update the CPUSVN because the
 *                              current SVN was not newer than CPUSVN. This is the most
 *                              common error code returned by EUPDATESVN.
 * @SGX_UNMASKED_EVENT:         An unmasked event, e.g. INTR, was received
 */
enum sgx_return_code {
        SGX_EPC_PAGE_CONFLICT           = 7,
        SGX_NOT_TRACKED                 = 11,
        SGX_CHILD_PRESENT               = 13,
        SGX_INVALID_EINITTOKEN          = 16,
        SGX_PAGE_NOT_MODIFIABLE         = 20,
        SGX_INSUFFICIENT_ENTROPY        = 29,
        SGX_NO_UPDATE                   = 31,
        SGX_UNMASKED_EVENT              = 128,
};

/* The modulus size for 3072-bit RSA keys. */
#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               184
#define SGX_SSA_MISC_EXINFO_SIZE        16

/**
 * enum sgx_attribute - 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.
 * @SGX_ATTR_ASYNC_EXIT_NOTIFY: Allow enclaves to be notified after an
 *                              asynchronous exit has occurred.
 */
enum sgx_attribute {
        SGX_ATTR_INIT              = BIT(0),
        SGX_ATTR_DEBUG             = BIT(1),
        SGX_ATTR_MODE64BIT         = BIT(2),
                                  /* BIT(3) is reserved */
        SGX_ATTR_PROVISIONKEY      = BIT(4),
        SGX_ATTR_EINITTOKENKEY     = BIT(5),
                                  /* BIT(6) is for CET */
        SGX_ATTR_KSS               = BIT(7),
                                  /* BIT(8) is reserved */
                                  /* BIT(9) is reserved */
        SGX_ATTR_ASYNC_EXIT_NOTIFY = BIT(10),
};

#define SGX_ATTR_RESERVED_MASK  (BIT_ULL(3) | \
                                 BIT_ULL(6) | \
                                 BIT_ULL(8) | \
                                 BIT_ULL(9) | \
                                 GENMASK_ULL(63, 11))

#define SGX_ATTR_UNPRIV_MASK    (SGX_ATTR_DEBUG     | \
                                 SGX_ATTR_MODE64BIT | \
                                 SGX_ATTR_KSS       | \
                                 SGX_ATTR_ASYNC_EXIT_NOTIFY)

#define SGX_ATTR_PRIV_MASK      (SGX_ATTR_PROVISIONKEY  | \
                                 SGX_ATTR_EINITTOKENKEY)

/**
 * 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
 * @config_id:          a user-defined value that is used in key derivation
 * @isv_prod_id:        a user-defined value that is used in key derivation
 * @isv_svn:            a user-defined value that is used in key derivation
 * @config_svn:         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] function.
 */
struct sgx_secs {
        u64 size;
        u64 base;
        u32 ssa_frame_size;
        u32 miscselect;
        u8  reserved1[24];
        u64 attributes;
        u64 xfrm;
        u32 mrenclave[8];
        u8  reserved2[32];
        u32 mrsigner[8];
        u8  reserved3[32];
        u32 config_id[16];
        u16 isv_prod_id;
        u16 isv_svn;
        u16 config_svn;
        u8  reserved4[3834];
} __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
 *
 * Make sure when making changes to this enum that its values can still fit
 * in the bitfield within &struct sgx_encl_page
 */
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:            constant 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_LAUNCH_TOKEN_SIZE 304

/*
 * Do not put any hardware-defined SGX structure representations below this
 * comment!
 */

#ifdef CONFIG_X86_SGX_KVM
int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs,
                     int *trapnr);
int sgx_virt_einit(void __user *sigstruct, void __user *token,
                   void __user *secs, u64 *lepubkeyhash, int *trapnr);
#endif

int sgx_set_attribute(unsigned long *allowed_attributes,
                      unsigned int attribute_fd);

#endif /* _ASM_X86_SGX_H */