xref: /linux/arch/x86/include/uapi/asm/sgx.h (revision 942baad211336efefb93a8369478888ab845c450)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /*
3  * Copyright(c) 2016-20 Intel Corporation.
4  */
5 #ifndef _UAPI_ASM_X86_SGX_H
6 #define _UAPI_ASM_X86_SGX_H
7 
8 #include <linux/types.h>
9 #include <linux/ioctl.h>
10 
11 /**
12  * enum sgx_page_flags - page control flags
13  * %SGX_PAGE_MEASURE:	Measure the page contents with a sequence of
14  *			ENCLS[EEXTEND] operations.
15  */
16 enum sgx_page_flags {
17 	SGX_PAGE_MEASURE	= 0x01,
18 };
19 
20 #define SGX_MAGIC 0xA4
21 
22 #define SGX_IOC_ENCLAVE_CREATE \
23 	_IOW(SGX_MAGIC, 0x00, struct sgx_enclave_create)
24 #define SGX_IOC_ENCLAVE_ADD_PAGES \
25 	_IOWR(SGX_MAGIC, 0x01, struct sgx_enclave_add_pages)
26 #define SGX_IOC_ENCLAVE_INIT \
27 	_IOW(SGX_MAGIC, 0x02, struct sgx_enclave_init)
28 #define SGX_IOC_ENCLAVE_PROVISION \
29 	_IOW(SGX_MAGIC, 0x03, struct sgx_enclave_provision)
30 
31 /**
32  * struct sgx_enclave_create - parameter structure for the
33  *                             %SGX_IOC_ENCLAVE_CREATE ioctl
34  * @src:	address for the SECS page data
35  */
36 struct sgx_enclave_create  {
37 	__u64	src;
38 };
39 
40 /**
41  * struct sgx_enclave_add_pages - parameter structure for the
42  *                                %SGX_IOC_ENCLAVE_ADD_PAGE ioctl
43  * @src:	start address for the page data
44  * @offset:	starting page offset
45  * @length:	length of the data (multiple of the page size)
46  * @secinfo:	address for the SECINFO data
47  * @flags:	page control flags
48  * @count:	number of bytes added (multiple of the page size)
49  */
50 struct sgx_enclave_add_pages {
51 	__u64 src;
52 	__u64 offset;
53 	__u64 length;
54 	__u64 secinfo;
55 	__u64 flags;
56 	__u64 count;
57 };
58 
59 /**
60  * struct sgx_enclave_init - parameter structure for the
61  *                           %SGX_IOC_ENCLAVE_INIT ioctl
62  * @sigstruct:	address for the SIGSTRUCT data
63  */
64 struct sgx_enclave_init {
65 	__u64 sigstruct;
66 };
67 
68 /**
69  * struct sgx_enclave_provision - parameter structure for the
70  *				  %SGX_IOC_ENCLAVE_PROVISION ioctl
71  * @fd:		file handle of /dev/sgx_provision
72  */
73 struct sgx_enclave_provision {
74 	__u64 fd;
75 };
76 
77 struct sgx_enclave_run;
78 
79 /**
80  * typedef sgx_enclave_user_handler_t - Exit handler function accepted by
81  *					__vdso_sgx_enter_enclave()
82  * @run:	The run instance given by the caller
83  *
84  * The register parameters contain the snapshot of their values at enclave
85  * exit. An invalid ENCLU function number will cause -EINVAL to be returned
86  * to the caller.
87  *
88  * Return:
89  * - <= 0:	The given value is returned back to the caller.
90  * - > 0:	ENCLU function to invoke, either EENTER or ERESUME.
91  */
92 typedef int (*sgx_enclave_user_handler_t)(long rdi, long rsi, long rdx,
93 					  long rsp, long r8, long r9,
94 					  struct sgx_enclave_run *run);
95 
96 /**
97  * struct sgx_enclave_run - the execution context of __vdso_sgx_enter_enclave()
98  * @tcs:			TCS used to enter the enclave
99  * @function:			The last seen ENCLU function (EENTER, ERESUME or EEXIT)
100  * @exception_vector:		The interrupt vector of the exception
101  * @exception_error_code:	The exception error code pulled out of the stack
102  * @exception_addr:		The address that triggered the exception
103  * @user_handler:		User provided callback run on exception
104  * @user_data:			Data passed to the user handler
105  * @reserved			Reserved for future extensions
106  *
107  * If @user_handler is provided, the handler will be invoked on all return paths
108  * of the normal flow.  The user handler may transfer control, e.g. via a
109  * longjmp() call or a C++ exception, without returning to
110  * __vdso_sgx_enter_enclave().
111  */
112 struct sgx_enclave_run {
113 	__u64 tcs;
114 	__u32 function;
115 	__u16 exception_vector;
116 	__u16 exception_error_code;
117 	__u64 exception_addr;
118 	__u64 user_handler;
119 	__u64 user_data;
120 	__u8  reserved[216];
121 };
122 
123 /**
124  * typedef vdso_sgx_enter_enclave_t - Prototype for __vdso_sgx_enter_enclave(),
125  *				      a vDSO function to enter an SGX enclave.
126  * @rdi:	Pass-through value for RDI
127  * @rsi:	Pass-through value for RSI
128  * @rdx:	Pass-through value for RDX
129  * @function:	ENCLU function, must be EENTER or ERESUME
130  * @r8:		Pass-through value for R8
131  * @r9:		Pass-through value for R9
132  * @run:	struct sgx_enclave_run, must be non-NULL
133  *
134  * NOTE: __vdso_sgx_enter_enclave() does not ensure full compliance with the
135  * x86-64 ABI, e.g. doesn't handle XSAVE state.  Except for non-volatile
136  * general purpose registers, EFLAGS.DF, and RSP alignment, preserving/setting
137  * state in accordance with the x86-64 ABI is the responsibility of the enclave
138  * and its runtime, i.e. __vdso_sgx_enter_enclave() cannot be called from C
139  * code without careful consideration by both the enclave and its runtime.
140  *
141  * All general purpose registers except RAX, RBX and RCX are passed as-is to the
142  * enclave.  RAX, RBX and RCX are consumed by EENTER and ERESUME and are loaded
143  * with @function, asynchronous exit pointer, and @run.tcs respectively.
144  *
145  * RBP and the stack are used to anchor __vdso_sgx_enter_enclave() to the
146  * pre-enclave state, e.g. to retrieve @run.exception and @run.user_handler
147  * after an enclave exit.  All other registers are available for use by the
148  * enclave and its runtime, e.g. an enclave can push additional data onto the
149  * stack (and modify RSP) to pass information to the optional user handler (see
150  * below).
151  *
152  * Most exceptions reported on ENCLU, including those that occur within the
153  * enclave, are fixed up and reported synchronously instead of being delivered
154  * via a standard signal. Debug Exceptions (#DB) and Breakpoints (#BP) are
155  * never fixed up and are always delivered via standard signals. On synchronously
156  * reported exceptions, -EFAULT is returned and details about the exception are
157  * recorded in @run.exception, the optional sgx_enclave_exception struct.
158  *
159  * Return:
160  * - 0:		ENCLU function was successfully executed.
161  * - -EINVAL:	Invalid ENCL number (neither EENTER nor ERESUME).
162  */
163 typedef int (*vdso_sgx_enter_enclave_t)(unsigned long rdi, unsigned long rsi,
164 					unsigned long rdx, unsigned int function,
165 					unsigned long r8,  unsigned long r9,
166 					struct sgx_enclave_run *run);
167 
168 #endif /* _UAPI_ASM_X86_SGX_H */
169