xref: /linux/arch/x86/include/asm/sgx.h (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
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 	EUPDATESVN	= 0x18,
47 };
48 
49 /**
50  * SGX_ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr
51  *
52  * ENCLS has its own (positive value) error codes and also generates
53  * ENCLS specific #GP and #PF faults.  And the ENCLS values get munged
54  * with system error codes as everything percolates back up the stack.
55  * Unfortunately (for us), we need to precisely identify each unique
56  * error code, e.g. the action taken if EWB fails varies based on the
57  * type of fault and on the exact SGX error code, i.e. we can't simply
58  * convert all faults to -EFAULT.
59  *
60  * To make all three error types coexist, we set bit 30 to identify an
61  * ENCLS fault.  Bit 31 (technically bits N:31) is used to differentiate
62  * between positive (faults and SGX error codes) and negative (system
63  * error codes) values.
64  */
65 #define SGX_ENCLS_FAULT_FLAG 0x40000000
66 
67 /**
68  * enum sgx_return_code - The return code type for ENCLS, ENCLU and ENCLV
69  * @SGX_EPC_PAGE_CONFLICT:	Page is being written by other ENCLS function.
70  * @SGX_NOT_TRACKED:		Previous ETRACK's shootdown sequence has not
71  *				been completed yet.
72  * @SGX_CHILD_PRESENT:		SECS has child pages present in the EPC.
73  * @SGX_INVALID_EINITTOKEN:	EINITTOKEN is invalid and enclave signer's
74  *				public key does not match IA32_SGXLEPUBKEYHASH.
75  * @SGX_PAGE_NOT_MODIFIABLE:	The EPC page cannot be modified because it
76  *				is in the PENDING or MODIFIED state.
77  * @SGX_INSUFFICIENT_ENTROPY:	Insufficient entropy in RNG.
78  * @SGX_NO_UPDATE:		EUPDATESVN could not update the CPUSVN because the
79  *				current SVN was not newer than CPUSVN. This is the most
80  *				common error code returned by EUPDATESVN.
81  * @SGX_UNMASKED_EVENT:		An unmasked event, e.g. INTR, was received
82  */
83 enum sgx_return_code {
84 	SGX_EPC_PAGE_CONFLICT		= 7,
85 	SGX_NOT_TRACKED			= 11,
86 	SGX_CHILD_PRESENT		= 13,
87 	SGX_INVALID_EINITTOKEN		= 16,
88 	SGX_PAGE_NOT_MODIFIABLE		= 20,
89 	SGX_INSUFFICIENT_ENTROPY	= 29,
90 	SGX_NO_UPDATE			= 31,
91 	SGX_UNMASKED_EVENT		= 128,
92 };
93 
94 /* The modulus size for 3072-bit RSA keys. */
95 #define SGX_MODULUS_SIZE 384
96 
97 /**
98  * enum sgx_miscselect - additional information to an SSA frame
99  * @SGX_MISC_EXINFO:	Report #PF or #GP to the SSA frame.
100  *
101  * Save State Area (SSA) is a stack inside the enclave used to store processor
102  * state when an exception or interrupt occurs. This enum defines additional
103  * information stored to an SSA frame.
104  */
105 enum sgx_miscselect {
106 	SGX_MISC_EXINFO		= BIT(0),
107 };
108 
109 #define SGX_MISC_RESERVED_MASK	GENMASK_ULL(63, 1)
110 
111 #define SGX_SSA_GPRS_SIZE		184
112 #define SGX_SSA_MISC_EXINFO_SIZE	16
113 
114 /**
115  * enum sgx_attribute - the attributes field in &struct sgx_secs
116  * @SGX_ATTR_INIT:		Enclave can be entered (is initialized).
117  * @SGX_ATTR_DEBUG:		Allow ENCLS(EDBGRD) and ENCLS(EDBGWR).
118  * @SGX_ATTR_MODE64BIT:		Tell that this a 64-bit enclave.
119  * @SGX_ATTR_PROVISIONKEY:      Allow to use provisioning keys for remote
120  *				attestation.
121  * @SGX_ATTR_KSS:		Allow to use key separation and sharing (KSS).
122  * @SGX_ATTR_EINITTOKENKEY:	Allow to use token signing key that is used to
123  *				sign cryptographic tokens that can be passed to
124  *				EINIT as an authorization to run an enclave.
125  * @SGX_ATTR_ASYNC_EXIT_NOTIFY:	Allow enclaves to be notified after an
126  *				asynchronous exit has occurred.
127  */
128 enum sgx_attribute {
129 	SGX_ATTR_INIT		   = BIT(0),
130 	SGX_ATTR_DEBUG		   = BIT(1),
131 	SGX_ATTR_MODE64BIT	   = BIT(2),
132 				  /* BIT(3) is reserved */
133 	SGX_ATTR_PROVISIONKEY	   = BIT(4),
134 	SGX_ATTR_EINITTOKENKEY	   = BIT(5),
135 				  /* BIT(6) is for CET */
136 	SGX_ATTR_KSS		   = BIT(7),
137 				  /* BIT(8) is reserved */
138 				  /* BIT(9) is reserved */
139 	SGX_ATTR_ASYNC_EXIT_NOTIFY = BIT(10),
140 };
141 
142 #define SGX_ATTR_RESERVED_MASK	(BIT_ULL(3) | \
143 				 BIT_ULL(6) | \
144 				 BIT_ULL(8) | \
145 				 BIT_ULL(9) | \
146 				 GENMASK_ULL(63, 11))
147 
148 #define SGX_ATTR_UNPRIV_MASK	(SGX_ATTR_DEBUG	    | \
149 				 SGX_ATTR_MODE64BIT | \
150 				 SGX_ATTR_KSS	    | \
151 				 SGX_ATTR_ASYNC_EXIT_NOTIFY)
152 
153 #define SGX_ATTR_PRIV_MASK	(SGX_ATTR_PROVISIONKEY	| \
154 				 SGX_ATTR_EINITTOKENKEY)
155 
156 /**
157  * struct sgx_secs - SGX Enclave Control Structure (SECS)
158  * @size:		size of the address space
159  * @base:		base address of the  address space
160  * @ssa_frame_size:	size of an SSA frame
161  * @miscselect:		additional information stored to an SSA frame
162  * @attributes:		attributes for enclave
163  * @xfrm:		XSave-Feature Request Mask (subset of XCR0)
164  * @mrenclave:		SHA256-hash of the enclave contents
165  * @mrsigner:		SHA256-hash of the public key used to sign the SIGSTRUCT
166  * @config_id:		a user-defined value that is used in key derivation
167  * @isv_prod_id:	a user-defined value that is used in key derivation
168  * @isv_svn:		a user-defined value that is used in key derivation
169  * @config_svn:		a user-defined value that is used in key derivation
170  *
171  * SGX Enclave Control Structure (SECS) is a special enclave page that is not
172  * visible in the address space. In fact, this structure defines the address
173  * range and other global attributes for the enclave and it is the first EPC
174  * page created for any enclave. It is moved from a temporary buffer to an EPC
175  * by the means of ENCLS[ECREATE] function.
176  */
177 struct sgx_secs {
178 	u64 size;
179 	u64 base;
180 	u32 ssa_frame_size;
181 	u32 miscselect;
182 	u8  reserved1[24];
183 	u64 attributes;
184 	u64 xfrm;
185 	u32 mrenclave[8];
186 	u8  reserved2[32];
187 	u32 mrsigner[8];
188 	u8  reserved3[32];
189 	u32 config_id[16];
190 	u16 isv_prod_id;
191 	u16 isv_svn;
192 	u16 config_svn;
193 	u8  reserved4[3834];
194 } __packed;
195 
196 /**
197  * enum sgx_tcs_flags - execution flags for TCS
198  * @SGX_TCS_DBGOPTIN:	If enabled allows single-stepping and breakpoints
199  *			inside an enclave. It is cleared by EADD but can
200  *			be set later with EDBGWR.
201  */
202 enum sgx_tcs_flags {
203 	SGX_TCS_DBGOPTIN	= 0x01,
204 };
205 
206 #define SGX_TCS_RESERVED_MASK	GENMASK_ULL(63, 1)
207 #define SGX_TCS_RESERVED_SIZE	4024
208 
209 /**
210  * struct sgx_tcs - Thread Control Structure (TCS)
211  * @state:		used to mark an entered TCS
212  * @flags:		execution flags (cleared by EADD)
213  * @ssa_offset:		SSA stack offset relative to the enclave base
214  * @ssa_index:		the current SSA frame index (cleard by EADD)
215  * @nr_ssa_frames:	the number of frame in the SSA stack
216  * @entry_offset:	entry point offset relative to the enclave base
217  * @exit_addr:		address outside the enclave to exit on an exception or
218  *			interrupt
219  * @fs_offset:		offset relative to the enclave base to become FS
220  *			segment inside the enclave
221  * @gs_offset:		offset relative to the enclave base to become GS
222  *			segment inside the enclave
223  * @fs_limit:		size to become a new FS-limit (only 32-bit enclaves)
224  * @gs_limit:		size to become a new GS-limit (only 32-bit enclaves)
225  *
226  * Thread Control Structure (TCS) is an enclave page visible in its address
227  * space that defines an entry point inside the enclave. A thread enters inside
228  * an enclave by supplying address of TCS to ENCLU(EENTER). A TCS can be entered
229  * by only one thread at a time.
230  */
231 struct sgx_tcs {
232 	u64 state;
233 	u64 flags;
234 	u64 ssa_offset;
235 	u32 ssa_index;
236 	u32 nr_ssa_frames;
237 	u64 entry_offset;
238 	u64 exit_addr;
239 	u64 fs_offset;
240 	u64 gs_offset;
241 	u32 fs_limit;
242 	u32 gs_limit;
243 	u8  reserved[SGX_TCS_RESERVED_SIZE];
244 } __packed;
245 
246 /**
247  * struct sgx_pageinfo - an enclave page descriptor
248  * @addr:	address of the enclave page
249  * @contents:	pointer to the page contents
250  * @metadata:	pointer either to a SECINFO or PCMD instance
251  * @secs:	address of the SECS page
252  */
253 struct sgx_pageinfo {
254 	u64 addr;
255 	u64 contents;
256 	u64 metadata;
257 	u64 secs;
258 } __packed __aligned(32);
259 
260 
261 /**
262  * enum sgx_page_type - bits in the SECINFO flags defining the page type
263  * @SGX_PAGE_TYPE_SECS:	a SECS page
264  * @SGX_PAGE_TYPE_TCS:	a TCS page
265  * @SGX_PAGE_TYPE_REG:	a regular page
266  * @SGX_PAGE_TYPE_VA:	a VA page
267  * @SGX_PAGE_TYPE_TRIM:	a page in trimmed state
268  *
269  * Make sure when making changes to this enum that its values can still fit
270  * in the bitfield within &struct sgx_encl_page
271  */
272 enum sgx_page_type {
273 	SGX_PAGE_TYPE_SECS,
274 	SGX_PAGE_TYPE_TCS,
275 	SGX_PAGE_TYPE_REG,
276 	SGX_PAGE_TYPE_VA,
277 	SGX_PAGE_TYPE_TRIM,
278 };
279 
280 #define SGX_NR_PAGE_TYPES	5
281 #define SGX_PAGE_TYPE_MASK	GENMASK(7, 0)
282 
283 /**
284  * enum sgx_secinfo_flags - the flags field in &struct sgx_secinfo
285  * @SGX_SECINFO_R:	allow read
286  * @SGX_SECINFO_W:	allow write
287  * @SGX_SECINFO_X:	allow execution
288  * @SGX_SECINFO_SECS:	a SECS page
289  * @SGX_SECINFO_TCS:	a TCS page
290  * @SGX_SECINFO_REG:	a regular page
291  * @SGX_SECINFO_VA:	a VA page
292  * @SGX_SECINFO_TRIM:	a page in trimmed state
293  */
294 enum sgx_secinfo_flags {
295 	SGX_SECINFO_R			= BIT(0),
296 	SGX_SECINFO_W			= BIT(1),
297 	SGX_SECINFO_X			= BIT(2),
298 	SGX_SECINFO_SECS		= (SGX_PAGE_TYPE_SECS << 8),
299 	SGX_SECINFO_TCS			= (SGX_PAGE_TYPE_TCS << 8),
300 	SGX_SECINFO_REG			= (SGX_PAGE_TYPE_REG << 8),
301 	SGX_SECINFO_VA			= (SGX_PAGE_TYPE_VA << 8),
302 	SGX_SECINFO_TRIM		= (SGX_PAGE_TYPE_TRIM << 8),
303 };
304 
305 #define SGX_SECINFO_PERMISSION_MASK	GENMASK_ULL(2, 0)
306 #define SGX_SECINFO_PAGE_TYPE_MASK	(SGX_PAGE_TYPE_MASK << 8)
307 #define SGX_SECINFO_RESERVED_MASK	~(SGX_SECINFO_PERMISSION_MASK | \
308 					  SGX_SECINFO_PAGE_TYPE_MASK)
309 
310 /**
311  * struct sgx_secinfo - describes attributes of an EPC page
312  * @flags:	permissions and type
313  *
314  * Used together with ENCLS leaves that add or modify an EPC page to an
315  * enclave to define page permissions and type.
316  */
317 struct sgx_secinfo {
318 	u64 flags;
319 	u8  reserved[56];
320 } __packed __aligned(64);
321 
322 #define SGX_PCMD_RESERVED_SIZE 40
323 
324 /**
325  * struct sgx_pcmd - Paging Crypto Metadata (PCMD)
326  * @enclave_id:	enclave identifier
327  * @mac:	MAC over PCMD, page contents and isvsvn
328  *
329  * PCMD is stored for every swapped page to the regular memory. When ELDU loads
330  * the page back it recalculates the MAC by using a isvsvn number stored in a
331  * VA page. Together these two structures bring integrity and rollback
332  * protection.
333  */
334 struct sgx_pcmd {
335 	struct sgx_secinfo secinfo;
336 	u64 enclave_id;
337 	u8  reserved[SGX_PCMD_RESERVED_SIZE];
338 	u8  mac[16];
339 } __packed __aligned(128);
340 
341 #define SGX_SIGSTRUCT_RESERVED1_SIZE 84
342 #define SGX_SIGSTRUCT_RESERVED2_SIZE 20
343 #define SGX_SIGSTRUCT_RESERVED3_SIZE 32
344 #define SGX_SIGSTRUCT_RESERVED4_SIZE 12
345 
346 /**
347  * struct sgx_sigstruct_header -  defines author of the enclave
348  * @header1:		constant byte string
349  * @vendor:		must be either 0x0000 or 0x8086
350  * @date:		YYYYMMDD in BCD
351  * @header2:		constant byte string
352  * @swdefined:		software defined value
353  */
354 struct sgx_sigstruct_header {
355 	u64 header1[2];
356 	u32 vendor;
357 	u32 date;
358 	u64 header2[2];
359 	u32 swdefined;
360 	u8  reserved1[84];
361 } __packed;
362 
363 /**
364  * struct sgx_sigstruct_body - defines contents of the enclave
365  * @miscselect:		additional information stored to an SSA frame
366  * @misc_mask:		required miscselect in SECS
367  * @attributes:		attributes for enclave
368  * @xfrm:		XSave-Feature Request Mask (subset of XCR0)
369  * @attributes_mask:	required attributes in SECS
370  * @xfrm_mask:		required XFRM in SECS
371  * @mrenclave:		SHA256-hash of the enclave contents
372  * @isvprodid:		a user-defined value that is used in key derivation
373  * @isvsvn:		a user-defined value that is used in key derivation
374  */
375 struct sgx_sigstruct_body {
376 	u32 miscselect;
377 	u32 misc_mask;
378 	u8  reserved2[20];
379 	u64 attributes;
380 	u64 xfrm;
381 	u64 attributes_mask;
382 	u64 xfrm_mask;
383 	u8  mrenclave[32];
384 	u8  reserved3[32];
385 	u16 isvprodid;
386 	u16 isvsvn;
387 } __packed;
388 
389 /**
390  * struct sgx_sigstruct - an enclave signature
391  * @header:		defines author of the enclave
392  * @modulus:		the modulus of the public key
393  * @exponent:		the exponent of the public key
394  * @signature:		the signature calculated over the fields except modulus,
395  * @body:		defines contents of the enclave
396  * @q1:			a value used in RSA signature verification
397  * @q2:			a value used in RSA signature verification
398  *
399  * Header and body are the parts that are actual signed. The remaining fields
400  * define the signature of the enclave.
401  */
402 struct sgx_sigstruct {
403 	struct sgx_sigstruct_header header;
404 	u8  modulus[SGX_MODULUS_SIZE];
405 	u32 exponent;
406 	u8  signature[SGX_MODULUS_SIZE];
407 	struct sgx_sigstruct_body body;
408 	u8  reserved4[12];
409 	u8  q1[SGX_MODULUS_SIZE];
410 	u8  q2[SGX_MODULUS_SIZE];
411 } __packed;
412 
413 #define SGX_LAUNCH_TOKEN_SIZE 304
414 
415 /*
416  * Do not put any hardware-defined SGX structure representations below this
417  * comment!
418  */
419 
420 #ifdef CONFIG_X86_SGX_KVM
421 int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs,
422 		     int *trapnr);
423 int sgx_virt_einit(void __user *sigstruct, void __user *token,
424 		   void __user *secs, u64 *lepubkeyhash, int *trapnr);
425 #endif
426 
427 int sgx_set_attribute(unsigned long *allowed_attributes,
428 		      unsigned int attribute_fd);
429 
430 #endif /* _ASM_X86_SGX_H */
431