xref: /openbmc/linux/arch/x86/include/asm/sgx.h (revision 1edd0337)
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  * %SGX_ATTR_ASYNC_EXIT_NOTIFY:	Allow enclaves to be notified after an
119  *				asynchronous exit has occurred.
120  */
121 enum sgx_attribute {
122 	SGX_ATTR_INIT		   = BIT(0),
123 	SGX_ATTR_DEBUG		   = BIT(1),
124 	SGX_ATTR_MODE64BIT	   = BIT(2),
125 				  /* BIT(3) is reserved */
126 	SGX_ATTR_PROVISIONKEY	   = BIT(4),
127 	SGX_ATTR_EINITTOKENKEY	   = BIT(5),
128 				  /* BIT(6) is for CET */
129 	SGX_ATTR_KSS		   = BIT(7),
130 				  /* BIT(8) is reserved */
131 				  /* BIT(9) is reserved */
132 	SGX_ATTR_ASYNC_EXIT_NOTIFY = BIT(10),
133 };
134 
135 #define SGX_ATTR_RESERVED_MASK	(BIT_ULL(3) | \
136 				 BIT_ULL(6) | \
137 				 BIT_ULL(8) | \
138 				 BIT_ULL(9) | \
139 				 GENMASK_ULL(63, 11))
140 
141 #define SGX_ATTR_UNPRIV_MASK	(SGX_ATTR_DEBUG	    | \
142 				 SGX_ATTR_MODE64BIT | \
143 				 SGX_ATTR_KSS	    | \
144 				 SGX_ATTR_ASYNC_EXIT_NOTIFY)
145 
146 #define SGX_ATTR_PRIV_MASK	(SGX_ATTR_PROVISIONKEY	| \
147 				 SGX_ATTR_EINITTOKENKEY)
148 
149 /**
150  * struct sgx_secs - SGX Enclave Control Structure (SECS)
151  * @size:		size of the address space
152  * @base:		base address of the  address space
153  * @ssa_frame_size:	size of an SSA frame
154  * @miscselect:		additional information stored to an SSA frame
155  * @attributes:		attributes for enclave
156  * @xfrm:		XSave-Feature Request Mask (subset of XCR0)
157  * @mrenclave:		SHA256-hash of the enclave contents
158  * @mrsigner:		SHA256-hash of the public key used to sign the SIGSTRUCT
159  * @config_id:		a user-defined value that is used in key derivation
160  * @isv_prod_id:	a user-defined value that is used in key derivation
161  * @isv_svn:		a user-defined value that is used in key derivation
162  * @config_svn:		a user-defined value that is used in key derivation
163  *
164  * SGX Enclave Control Structure (SECS) is a special enclave page that is not
165  * visible in the address space. In fact, this structure defines the address
166  * range and other global attributes for the enclave and it is the first EPC
167  * page created for any enclave. It is moved from a temporary buffer to an EPC
168  * by the means of ENCLS[ECREATE] function.
169  */
170 struct sgx_secs {
171 	u64 size;
172 	u64 base;
173 	u32 ssa_frame_size;
174 	u32 miscselect;
175 	u8  reserved1[24];
176 	u64 attributes;
177 	u64 xfrm;
178 	u32 mrenclave[8];
179 	u8  reserved2[32];
180 	u32 mrsigner[8];
181 	u8  reserved3[32];
182 	u32 config_id[16];
183 	u16 isv_prod_id;
184 	u16 isv_svn;
185 	u16 config_svn;
186 	u8  reserved4[3834];
187 } __packed;
188 
189 /**
190  * enum sgx_tcs_flags - execution flags for TCS
191  * %SGX_TCS_DBGOPTIN:	If enabled allows single-stepping and breakpoints
192  *			inside an enclave. It is cleared by EADD but can
193  *			be set later with EDBGWR.
194  */
195 enum sgx_tcs_flags {
196 	SGX_TCS_DBGOPTIN	= 0x01,
197 };
198 
199 #define SGX_TCS_RESERVED_MASK	GENMASK_ULL(63, 1)
200 #define SGX_TCS_RESERVED_SIZE	4024
201 
202 /**
203  * struct sgx_tcs - Thread Control Structure (TCS)
204  * @state:		used to mark an entered TCS
205  * @flags:		execution flags (cleared by EADD)
206  * @ssa_offset:		SSA stack offset relative to the enclave base
207  * @ssa_index:		the current SSA frame index (cleard by EADD)
208  * @nr_ssa_frames:	the number of frame in the SSA stack
209  * @entry_offset:	entry point offset relative to the enclave base
210  * @exit_addr:		address outside the enclave to exit on an exception or
211  *			interrupt
212  * @fs_offset:		offset relative to the enclave base to become FS
213  *			segment inside the enclave
214  * @gs_offset:		offset relative to the enclave base to become GS
215  *			segment inside the enclave
216  * @fs_limit:		size to become a new FS-limit (only 32-bit enclaves)
217  * @gs_limit:		size to become a new GS-limit (only 32-bit enclaves)
218  *
219  * Thread Control Structure (TCS) is an enclave page visible in its address
220  * space that defines an entry point inside the enclave. A thread enters inside
221  * an enclave by supplying address of TCS to ENCLU(EENTER). A TCS can be entered
222  * by only one thread at a time.
223  */
224 struct sgx_tcs {
225 	u64 state;
226 	u64 flags;
227 	u64 ssa_offset;
228 	u32 ssa_index;
229 	u32 nr_ssa_frames;
230 	u64 entry_offset;
231 	u64 exit_addr;
232 	u64 fs_offset;
233 	u64 gs_offset;
234 	u32 fs_limit;
235 	u32 gs_limit;
236 	u8  reserved[SGX_TCS_RESERVED_SIZE];
237 } __packed;
238 
239 /**
240  * struct sgx_pageinfo - an enclave page descriptor
241  * @addr:	address of the enclave page
242  * @contents:	pointer to the page contents
243  * @metadata:	pointer either to a SECINFO or PCMD instance
244  * @secs:	address of the SECS page
245  */
246 struct sgx_pageinfo {
247 	u64 addr;
248 	u64 contents;
249 	u64 metadata;
250 	u64 secs;
251 } __packed __aligned(32);
252 
253 
254 /**
255  * enum sgx_page_type - bits in the SECINFO flags defining the page type
256  * %SGX_PAGE_TYPE_SECS:	a SECS page
257  * %SGX_PAGE_TYPE_TCS:	a TCS page
258  * %SGX_PAGE_TYPE_REG:	a regular page
259  * %SGX_PAGE_TYPE_VA:	a VA page
260  * %SGX_PAGE_TYPE_TRIM:	a page in trimmed state
261  *
262  * Make sure when making changes to this enum that its values can still fit
263  * in the bitfield within &struct sgx_encl_page
264  */
265 enum sgx_page_type {
266 	SGX_PAGE_TYPE_SECS,
267 	SGX_PAGE_TYPE_TCS,
268 	SGX_PAGE_TYPE_REG,
269 	SGX_PAGE_TYPE_VA,
270 	SGX_PAGE_TYPE_TRIM,
271 };
272 
273 #define SGX_NR_PAGE_TYPES	5
274 #define SGX_PAGE_TYPE_MASK	GENMASK(7, 0)
275 
276 /**
277  * enum sgx_secinfo_flags - the flags field in &struct sgx_secinfo
278  * %SGX_SECINFO_R:	allow read
279  * %SGX_SECINFO_W:	allow write
280  * %SGX_SECINFO_X:	allow execution
281  * %SGX_SECINFO_SECS:	a SECS page
282  * %SGX_SECINFO_TCS:	a TCS page
283  * %SGX_SECINFO_REG:	a regular page
284  * %SGX_SECINFO_VA:	a VA page
285  * %SGX_SECINFO_TRIM:	a page in trimmed state
286  */
287 enum sgx_secinfo_flags {
288 	SGX_SECINFO_R			= BIT(0),
289 	SGX_SECINFO_W			= BIT(1),
290 	SGX_SECINFO_X			= BIT(2),
291 	SGX_SECINFO_SECS		= (SGX_PAGE_TYPE_SECS << 8),
292 	SGX_SECINFO_TCS			= (SGX_PAGE_TYPE_TCS << 8),
293 	SGX_SECINFO_REG			= (SGX_PAGE_TYPE_REG << 8),
294 	SGX_SECINFO_VA			= (SGX_PAGE_TYPE_VA << 8),
295 	SGX_SECINFO_TRIM		= (SGX_PAGE_TYPE_TRIM << 8),
296 };
297 
298 #define SGX_SECINFO_PERMISSION_MASK	GENMASK_ULL(2, 0)
299 #define SGX_SECINFO_PAGE_TYPE_MASK	(SGX_PAGE_TYPE_MASK << 8)
300 #define SGX_SECINFO_RESERVED_MASK	~(SGX_SECINFO_PERMISSION_MASK | \
301 					  SGX_SECINFO_PAGE_TYPE_MASK)
302 
303 /**
304  * struct sgx_secinfo - describes attributes of an EPC page
305  * @flags:	permissions and type
306  *
307  * Used together with ENCLS leaves that add or modify an EPC page to an
308  * enclave to define page permissions and type.
309  */
310 struct sgx_secinfo {
311 	u64 flags;
312 	u8  reserved[56];
313 } __packed __aligned(64);
314 
315 #define SGX_PCMD_RESERVED_SIZE 40
316 
317 /**
318  * struct sgx_pcmd - Paging Crypto Metadata (PCMD)
319  * @enclave_id:	enclave identifier
320  * @mac:	MAC over PCMD, page contents and isvsvn
321  *
322  * PCMD is stored for every swapped page to the regular memory. When ELDU loads
323  * the page back it recalculates the MAC by using a isvsvn number stored in a
324  * VA page. Together these two structures bring integrity and rollback
325  * protection.
326  */
327 struct sgx_pcmd {
328 	struct sgx_secinfo secinfo;
329 	u64 enclave_id;
330 	u8  reserved[SGX_PCMD_RESERVED_SIZE];
331 	u8  mac[16];
332 } __packed __aligned(128);
333 
334 #define SGX_SIGSTRUCT_RESERVED1_SIZE 84
335 #define SGX_SIGSTRUCT_RESERVED2_SIZE 20
336 #define SGX_SIGSTRUCT_RESERVED3_SIZE 32
337 #define SGX_SIGSTRUCT_RESERVED4_SIZE 12
338 
339 /**
340  * struct sgx_sigstruct_header -  defines author of the enclave
341  * @header1:		constant byte string
342  * @vendor:		must be either 0x0000 or 0x8086
343  * @date:		YYYYMMDD in BCD
344  * @header2:		constant byte string
345  * @swdefined:		software defined value
346  */
347 struct sgx_sigstruct_header {
348 	u64 header1[2];
349 	u32 vendor;
350 	u32 date;
351 	u64 header2[2];
352 	u32 swdefined;
353 	u8  reserved1[84];
354 } __packed;
355 
356 /**
357  * struct sgx_sigstruct_body - defines contents of the enclave
358  * @miscselect:		additional information stored to an SSA frame
359  * @misc_mask:		required miscselect in SECS
360  * @attributes:		attributes for enclave
361  * @xfrm:		XSave-Feature Request Mask (subset of XCR0)
362  * @attributes_mask:	required attributes in SECS
363  * @xfrm_mask:		required XFRM in SECS
364  * @mrenclave:		SHA256-hash of the enclave contents
365  * @isvprodid:		a user-defined value that is used in key derivation
366  * @isvsvn:		a user-defined value that is used in key derivation
367  */
368 struct sgx_sigstruct_body {
369 	u32 miscselect;
370 	u32 misc_mask;
371 	u8  reserved2[20];
372 	u64 attributes;
373 	u64 xfrm;
374 	u64 attributes_mask;
375 	u64 xfrm_mask;
376 	u8  mrenclave[32];
377 	u8  reserved3[32];
378 	u16 isvprodid;
379 	u16 isvsvn;
380 } __packed;
381 
382 /**
383  * struct sgx_sigstruct - an enclave signature
384  * @header:		defines author of the enclave
385  * @modulus:		the modulus of the public key
386  * @exponent:		the exponent of the public key
387  * @signature:		the signature calculated over the fields except modulus,
388  * @body:		defines contents of the enclave
389  * @q1:			a value used in RSA signature verification
390  * @q2:			a value used in RSA signature verification
391  *
392  * Header and body are the parts that are actual signed. The remaining fields
393  * define the signature of the enclave.
394  */
395 struct sgx_sigstruct {
396 	struct sgx_sigstruct_header header;
397 	u8  modulus[SGX_MODULUS_SIZE];
398 	u32 exponent;
399 	u8  signature[SGX_MODULUS_SIZE];
400 	struct sgx_sigstruct_body body;
401 	u8  reserved4[12];
402 	u8  q1[SGX_MODULUS_SIZE];
403 	u8  q2[SGX_MODULUS_SIZE];
404 } __packed;
405 
406 #define SGX_LAUNCH_TOKEN_SIZE 304
407 
408 /*
409  * Do not put any hardware-defined SGX structure representations below this
410  * comment!
411  */
412 
413 #ifdef CONFIG_X86_SGX_KVM
414 int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs,
415 		     int *trapnr);
416 int sgx_virt_einit(void __user *sigstruct, void __user *token,
417 		   void __user *secs, u64 *lepubkeyhash, int *trapnr);
418 #endif
419 
420 int sgx_set_attribute(unsigned long *allowed_attributes,
421 		      unsigned int attribute_fd);
422 
423 #endif /* _ASM_X86_SGX_H */
424