xref: /openbmc/linux/arch/x86/include/asm/sgx.h (revision 8ab59da2)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /**
3  * Copyright(c) 2016-20 Intel Corporation.
4  *
5  * Intel Software Guard Extensions (SGX) support.
6  */
7 #ifndef _ASM_X86_SGX_H
8 #define _ASM_X86_SGX_H
9 
10 #include <linux/bits.h>
11 #include <linux/types.h>
12 
13 /*
14  * This file contains both data structures defined by SGX architecture and Linux
15  * defined software data structures and functions.  The two should not be mixed
16  * together for better readability.  The architectural definitions come first.
17  */
18 
19 /* The SGX specific CPUID function. */
20 #define SGX_CPUID		0x12
21 /* EPC enumeration. */
22 #define SGX_CPUID_EPC		2
23 /* An invalid EPC section, i.e. the end marker. */
24 #define SGX_CPUID_EPC_INVALID	0x0
25 /* A valid EPC section. */
26 #define SGX_CPUID_EPC_SECTION	0x1
27 /* The bitmask for the EPC section type. */
28 #define SGX_CPUID_EPC_MASK	GENMASK(3, 0)
29 
30 enum sgx_encls_function {
31 	ECREATE	= 0x00,
32 	EADD	= 0x01,
33 	EINIT	= 0x02,
34 	EREMOVE	= 0x03,
35 	EDGBRD	= 0x04,
36 	EDGBWR	= 0x05,
37 	EEXTEND	= 0x06,
38 	ELDU	= 0x08,
39 	EBLOCK	= 0x09,
40 	EPA	= 0x0A,
41 	EWB	= 0x0B,
42 	ETRACK	= 0x0C,
43 	EAUG	= 0x0D,
44 	EMODPR	= 0x0E,
45 	EMODT	= 0x0F,
46 };
47 
48 /**
49  * SGX_ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr
50  *
51  * ENCLS has its own (positive value) error codes and also generates
52  * ENCLS specific #GP and #PF faults.  And the ENCLS values get munged
53  * with system error codes as everything percolates back up the stack.
54  * Unfortunately (for us), we need to precisely identify each unique
55  * error code, e.g. the action taken if EWB fails varies based on the
56  * type of fault and on the exact SGX error code, i.e. we can't simply
57  * convert all faults to -EFAULT.
58  *
59  * To make all three error types coexist, we set bit 30 to identify an
60  * ENCLS fault.  Bit 31 (technically bits N:31) is used to differentiate
61  * between positive (faults and SGX error codes) and negative (system
62  * error codes) values.
63  */
64 #define SGX_ENCLS_FAULT_FLAG 0x40000000
65 
66 /**
67  * enum sgx_return_code - The return code type for ENCLS, ENCLU and ENCLV
68  * %SGX_EPC_PAGE_CONFLICT:	Page is being written by other ENCLS function.
69  * %SGX_NOT_TRACKED:		Previous ETRACK's shootdown sequence has not
70  *				been completed yet.
71  * %SGX_CHILD_PRESENT		SECS has child pages present in the EPC.
72  * %SGX_INVALID_EINITTOKEN:	EINITTOKEN is invalid and enclave signer's
73  *				public key does not match IA32_SGXLEPUBKEYHASH.
74  * %SGX_PAGE_NOT_MODIFIABLE:	The EPC page cannot be modified because it
75  *				is in the PENDING or MODIFIED state.
76  * %SGX_UNMASKED_EVENT:		An unmasked event, e.g. INTR, was received
77  */
78 enum sgx_return_code {
79 	SGX_EPC_PAGE_CONFLICT		= 7,
80 	SGX_NOT_TRACKED			= 11,
81 	SGX_CHILD_PRESENT		= 13,
82 	SGX_INVALID_EINITTOKEN		= 16,
83 	SGX_PAGE_NOT_MODIFIABLE		= 20,
84 	SGX_UNMASKED_EVENT		= 128,
85 };
86 
87 /* The modulus size for 3072-bit RSA keys. */
88 #define SGX_MODULUS_SIZE 384
89 
90 /**
91  * enum sgx_miscselect - additional information to an SSA frame
92  * %SGX_MISC_EXINFO:	Report #PF or #GP to the SSA frame.
93  *
94  * Save State Area (SSA) is a stack inside the enclave used to store processor
95  * state when an exception or interrupt occurs. This enum defines additional
96  * information stored to an SSA frame.
97  */
98 enum sgx_miscselect {
99 	SGX_MISC_EXINFO		= BIT(0),
100 };
101 
102 #define SGX_MISC_RESERVED_MASK	GENMASK_ULL(63, 1)
103 
104 #define SGX_SSA_GPRS_SIZE		184
105 #define SGX_SSA_MISC_EXINFO_SIZE	16
106 
107 /**
108  * enum sgx_attributes - the attributes field in &struct sgx_secs
109  * %SGX_ATTR_INIT:		Enclave can be entered (is initialized).
110  * %SGX_ATTR_DEBUG:		Allow ENCLS(EDBGRD) and ENCLS(EDBGWR).
111  * %SGX_ATTR_MODE64BIT:		Tell that this a 64-bit enclave.
112  * %SGX_ATTR_PROVISIONKEY:      Allow to use provisioning keys for remote
113  *				attestation.
114  * %SGX_ATTR_KSS:		Allow to use key separation and sharing (KSS).
115  * %SGX_ATTR_EINITTOKENKEY:	Allow to use token signing key that is used to
116  *				sign cryptographic tokens that can be passed to
117  *				EINIT as an authorization to run an enclave.
118  */
119 enum sgx_attribute {
120 	SGX_ATTR_INIT		= BIT(0),
121 	SGX_ATTR_DEBUG		= BIT(1),
122 	SGX_ATTR_MODE64BIT	= BIT(2),
123 	SGX_ATTR_PROVISIONKEY	= BIT(4),
124 	SGX_ATTR_EINITTOKENKEY	= BIT(5),
125 	SGX_ATTR_KSS		= BIT(7),
126 };
127 
128 #define SGX_ATTR_RESERVED_MASK	(BIT_ULL(3) | BIT_ULL(6) | GENMASK_ULL(63, 8))
129 
130 /**
131  * struct sgx_secs - SGX Enclave Control Structure (SECS)
132  * @size:		size of the address space
133  * @base:		base address of the  address space
134  * @ssa_frame_size:	size of an SSA frame
135  * @miscselect:		additional information stored to an SSA frame
136  * @attributes:		attributes for enclave
137  * @xfrm:		XSave-Feature Request Mask (subset of XCR0)
138  * @mrenclave:		SHA256-hash of the enclave contents
139  * @mrsigner:		SHA256-hash of the public key used to sign the SIGSTRUCT
140  * @config_id:		a user-defined value that is used in key derivation
141  * @isv_prod_id:	a user-defined value that is used in key derivation
142  * @isv_svn:		a user-defined value that is used in key derivation
143  * @config_svn:		a user-defined value that is used in key derivation
144  *
145  * SGX Enclave Control Structure (SECS) is a special enclave page that is not
146  * visible in the address space. In fact, this structure defines the address
147  * range and other global attributes for the enclave and it is the first EPC
148  * page created for any enclave. It is moved from a temporary buffer to an EPC
149  * by the means of ENCLS[ECREATE] function.
150  */
151 struct sgx_secs {
152 	u64 size;
153 	u64 base;
154 	u32 ssa_frame_size;
155 	u32 miscselect;
156 	u8  reserved1[24];
157 	u64 attributes;
158 	u64 xfrm;
159 	u32 mrenclave[8];
160 	u8  reserved2[32];
161 	u32 mrsigner[8];
162 	u8  reserved3[32];
163 	u32 config_id[16];
164 	u16 isv_prod_id;
165 	u16 isv_svn;
166 	u16 config_svn;
167 	u8  reserved4[3834];
168 } __packed;
169 
170 /**
171  * enum sgx_tcs_flags - execution flags for TCS
172  * %SGX_TCS_DBGOPTIN:	If enabled allows single-stepping and breakpoints
173  *			inside an enclave. It is cleared by EADD but can
174  *			be set later with EDBGWR.
175  */
176 enum sgx_tcs_flags {
177 	SGX_TCS_DBGOPTIN	= 0x01,
178 };
179 
180 #define SGX_TCS_RESERVED_MASK	GENMASK_ULL(63, 1)
181 #define SGX_TCS_RESERVED_SIZE	4024
182 
183 /**
184  * struct sgx_tcs - Thread Control Structure (TCS)
185  * @state:		used to mark an entered TCS
186  * @flags:		execution flags (cleared by EADD)
187  * @ssa_offset:		SSA stack offset relative to the enclave base
188  * @ssa_index:		the current SSA frame index (cleard by EADD)
189  * @nr_ssa_frames:	the number of frame in the SSA stack
190  * @entry_offset:	entry point offset relative to the enclave base
191  * @exit_addr:		address outside the enclave to exit on an exception or
192  *			interrupt
193  * @fs_offset:		offset relative to the enclave base to become FS
194  *			segment inside the enclave
195  * @gs_offset:		offset relative to the enclave base to become GS
196  *			segment inside the enclave
197  * @fs_limit:		size to become a new FS-limit (only 32-bit enclaves)
198  * @gs_limit:		size to become a new GS-limit (only 32-bit enclaves)
199  *
200  * Thread Control Structure (TCS) is an enclave page visible in its address
201  * space that defines an entry point inside the enclave. A thread enters inside
202  * an enclave by supplying address of TCS to ENCLU(EENTER). A TCS can be entered
203  * by only one thread at a time.
204  */
205 struct sgx_tcs {
206 	u64 state;
207 	u64 flags;
208 	u64 ssa_offset;
209 	u32 ssa_index;
210 	u32 nr_ssa_frames;
211 	u64 entry_offset;
212 	u64 exit_addr;
213 	u64 fs_offset;
214 	u64 gs_offset;
215 	u32 fs_limit;
216 	u32 gs_limit;
217 	u8  reserved[SGX_TCS_RESERVED_SIZE];
218 } __packed;
219 
220 /**
221  * struct sgx_pageinfo - an enclave page descriptor
222  * @addr:	address of the enclave page
223  * @contents:	pointer to the page contents
224  * @metadata:	pointer either to a SECINFO or PCMD instance
225  * @secs:	address of the SECS page
226  */
227 struct sgx_pageinfo {
228 	u64 addr;
229 	u64 contents;
230 	u64 metadata;
231 	u64 secs;
232 } __packed __aligned(32);
233 
234 
235 /**
236  * enum sgx_page_type - bits in the SECINFO flags defining the page type
237  * %SGX_PAGE_TYPE_SECS:	a SECS page
238  * %SGX_PAGE_TYPE_TCS:	a TCS page
239  * %SGX_PAGE_TYPE_REG:	a regular page
240  * %SGX_PAGE_TYPE_VA:	a VA page
241  * %SGX_PAGE_TYPE_TRIM:	a page in trimmed state
242  *
243  * Make sure when making changes to this enum that its values can still fit
244  * in the bitfield within &struct sgx_encl_page
245  */
246 enum sgx_page_type {
247 	SGX_PAGE_TYPE_SECS,
248 	SGX_PAGE_TYPE_TCS,
249 	SGX_PAGE_TYPE_REG,
250 	SGX_PAGE_TYPE_VA,
251 	SGX_PAGE_TYPE_TRIM,
252 };
253 
254 #define SGX_NR_PAGE_TYPES	5
255 #define SGX_PAGE_TYPE_MASK	GENMASK(7, 0)
256 
257 /**
258  * enum sgx_secinfo_flags - the flags field in &struct sgx_secinfo
259  * %SGX_SECINFO_R:	allow read
260  * %SGX_SECINFO_W:	allow write
261  * %SGX_SECINFO_X:	allow execution
262  * %SGX_SECINFO_SECS:	a SECS page
263  * %SGX_SECINFO_TCS:	a TCS page
264  * %SGX_SECINFO_REG:	a regular page
265  * %SGX_SECINFO_VA:	a VA page
266  * %SGX_SECINFO_TRIM:	a page in trimmed state
267  */
268 enum sgx_secinfo_flags {
269 	SGX_SECINFO_R			= BIT(0),
270 	SGX_SECINFO_W			= BIT(1),
271 	SGX_SECINFO_X			= BIT(2),
272 	SGX_SECINFO_SECS		= (SGX_PAGE_TYPE_SECS << 8),
273 	SGX_SECINFO_TCS			= (SGX_PAGE_TYPE_TCS << 8),
274 	SGX_SECINFO_REG			= (SGX_PAGE_TYPE_REG << 8),
275 	SGX_SECINFO_VA			= (SGX_PAGE_TYPE_VA << 8),
276 	SGX_SECINFO_TRIM		= (SGX_PAGE_TYPE_TRIM << 8),
277 };
278 
279 #define SGX_SECINFO_PERMISSION_MASK	GENMASK_ULL(2, 0)
280 #define SGX_SECINFO_PAGE_TYPE_MASK	(SGX_PAGE_TYPE_MASK << 8)
281 #define SGX_SECINFO_RESERVED_MASK	~(SGX_SECINFO_PERMISSION_MASK | \
282 					  SGX_SECINFO_PAGE_TYPE_MASK)
283 
284 /**
285  * struct sgx_secinfo - describes attributes of an EPC page
286  * @flags:	permissions and type
287  *
288  * Used together with ENCLS leaves that add or modify an EPC page to an
289  * enclave to define page permissions and type.
290  */
291 struct sgx_secinfo {
292 	u64 flags;
293 	u8  reserved[56];
294 } __packed __aligned(64);
295 
296 #define SGX_PCMD_RESERVED_SIZE 40
297 
298 /**
299  * struct sgx_pcmd - Paging Crypto Metadata (PCMD)
300  * @enclave_id:	enclave identifier
301  * @mac:	MAC over PCMD, page contents and isvsvn
302  *
303  * PCMD is stored for every swapped page to the regular memory. When ELDU loads
304  * the page back it recalculates the MAC by using a isvsvn number stored in a
305  * VA page. Together these two structures bring integrity and rollback
306  * protection.
307  */
308 struct sgx_pcmd {
309 	struct sgx_secinfo secinfo;
310 	u64 enclave_id;
311 	u8  reserved[SGX_PCMD_RESERVED_SIZE];
312 	u8  mac[16];
313 } __packed __aligned(128);
314 
315 #define SGX_SIGSTRUCT_RESERVED1_SIZE 84
316 #define SGX_SIGSTRUCT_RESERVED2_SIZE 20
317 #define SGX_SIGSTRUCT_RESERVED3_SIZE 32
318 #define SGX_SIGSTRUCT_RESERVED4_SIZE 12
319 
320 /**
321  * struct sgx_sigstruct_header -  defines author of the enclave
322  * @header1:		constant byte string
323  * @vendor:		must be either 0x0000 or 0x8086
324  * @date:		YYYYMMDD in BCD
325  * @header2:		constant byte string
326  * @swdefined:		software defined value
327  */
328 struct sgx_sigstruct_header {
329 	u64 header1[2];
330 	u32 vendor;
331 	u32 date;
332 	u64 header2[2];
333 	u32 swdefined;
334 	u8  reserved1[84];
335 } __packed;
336 
337 /**
338  * struct sgx_sigstruct_body - defines contents of the enclave
339  * @miscselect:		additional information stored to an SSA frame
340  * @misc_mask:		required miscselect in SECS
341  * @attributes:		attributes for enclave
342  * @xfrm:		XSave-Feature Request Mask (subset of XCR0)
343  * @attributes_mask:	required attributes in SECS
344  * @xfrm_mask:		required XFRM in SECS
345  * @mrenclave:		SHA256-hash of the enclave contents
346  * @isvprodid:		a user-defined value that is used in key derivation
347  * @isvsvn:		a user-defined value that is used in key derivation
348  */
349 struct sgx_sigstruct_body {
350 	u32 miscselect;
351 	u32 misc_mask;
352 	u8  reserved2[20];
353 	u64 attributes;
354 	u64 xfrm;
355 	u64 attributes_mask;
356 	u64 xfrm_mask;
357 	u8  mrenclave[32];
358 	u8  reserved3[32];
359 	u16 isvprodid;
360 	u16 isvsvn;
361 } __packed;
362 
363 /**
364  * struct sgx_sigstruct - an enclave signature
365  * @header:		defines author of the enclave
366  * @modulus:		the modulus of the public key
367  * @exponent:		the exponent of the public key
368  * @signature:		the signature calculated over the fields except modulus,
369  * @body:		defines contents of the enclave
370  * @q1:			a value used in RSA signature verification
371  * @q2:			a value used in RSA signature verification
372  *
373  * Header and body are the parts that are actual signed. The remaining fields
374  * define the signature of the enclave.
375  */
376 struct sgx_sigstruct {
377 	struct sgx_sigstruct_header header;
378 	u8  modulus[SGX_MODULUS_SIZE];
379 	u32 exponent;
380 	u8  signature[SGX_MODULUS_SIZE];
381 	struct sgx_sigstruct_body body;
382 	u8  reserved4[12];
383 	u8  q1[SGX_MODULUS_SIZE];
384 	u8  q2[SGX_MODULUS_SIZE];
385 } __packed;
386 
387 #define SGX_LAUNCH_TOKEN_SIZE 304
388 
389 /*
390  * Do not put any hardware-defined SGX structure representations below this
391  * comment!
392  */
393 
394 #ifdef CONFIG_X86_SGX_KVM
395 int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs,
396 		     int *trapnr);
397 int sgx_virt_einit(void __user *sigstruct, void __user *token,
398 		   void __user *secs, u64 *lepubkeyhash, int *trapnr);
399 #endif
400 
401 int sgx_set_attribute(unsigned long *allowed_attributes,
402 		      unsigned int attribute_fd);
403 
404 #endif /* _ASM_X86_SGX_H */
405