Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'x86_sgx_for_6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SGX updates from Dave HansenL
"The main content here is adding support for the new EUPDATESVN SGX
ISA. Before this, folks who updated microcode had to reboot before
enclaves could attest to the new microcode. The new functionality lets
them do this without a reboot.
The rest are some nice, but relatively mundane comment and kernel-doc
fixups.
Summary:
- Allow security version (SVN) updates so enclaves can attest to new
microcode
- Fix kernel docs typos"
* tag 'x86_sgx_for_6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sgx: Fix a typo in the kernel-doc comment for enum sgx_attribute
x86/sgx: Remove superfluous asterisk from copyright comment in asm/sgx.h
x86/sgx: Document structs and enums with '@', not '%'
x86/sgx: Add kernel-doc descriptions for params passed to vDSO user handler
x86/sgx: Add a missing colon in kernel-doc markup for "struct sgx_enclave_run"
x86/sgx: Enable automatic SVN updates for SGX enclaves
x86/sgx: Implement ENCLS[EUPDATESVN]
x86/sgx: Define error codes for use by ENCLS[EUPDATESVN]
x86/cpufeatures: Add X86_FEATURE_SGX_EUPDATESVN feature flag
x86/sgx: Introduce functions to count the sgx_(vepc_)open()
+210
-49
+1
arch/x86/include/asm/cpufeatures.h
+1
arch/x86/include/asm/cpufeatures.h
···
499
499
#define X86_FEATURE_IBPB_EXIT_TO_USER (21*32+14) /* Use IBPB on exit-to-userspace, see VMSCAPE bug */
500
500
#define X86_FEATURE_ABMC (21*32+15) /* Assignable Bandwidth Monitoring Counters */
501
501
#define X86_FEATURE_MSR_IMM (21*32+16) /* MSR immediate form instructions */
502
+
#define X86_FEATURE_SGX_EUPDATESVN (21*32+17) /* Support for ENCLS[EUPDATESVN] instruction */
502
503
503
504
#define X86_FEATURE_SDCIAE (21*32+18) /* L3 Smart Data Cache Injection Allocation Enforcement */
504
505
+52
-45
arch/x86/include/asm/sgx.h
+52
-45
arch/x86/include/asm/sgx.h
···
1
1
/* SPDX-License-Identifier: GPL-2.0 */
2
-
/**
2
+
/*
3
3
* Copyright(c) 2016-20 Intel Corporation.
4
4
*
5
5
* Intel Software Guard Extensions (SGX) support.
···
28
28
#define SGX_CPUID_EPC_MASK GENMASK(3, 0)
29
29
30
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,
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,
46
47
};
47
48
48
49
/**
···
66
65
67
66
/**
68
67
* 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
68
+
* @SGX_EPC_PAGE_CONFLICT: Page is being written by other ENCLS function.
69
+
* @SGX_NOT_TRACKED: Previous ETRACK's shootdown sequence has not
71
70
* 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
71
+
* @SGX_CHILD_PRESENT: SECS has child pages present in the EPC.
72
+
* @SGX_INVALID_EINITTOKEN: EINITTOKEN is invalid and enclave signer's
74
73
* public key does not match IA32_SGXLEPUBKEYHASH.
75
-
* %SGX_PAGE_NOT_MODIFIABLE: The EPC page cannot be modified because it
74
+
* @SGX_PAGE_NOT_MODIFIABLE: The EPC page cannot be modified because it
76
75
* is in the PENDING or MODIFIED state.
77
-
* %SGX_UNMASKED_EVENT: An unmasked event, e.g. INTR, was received
76
+
* @SGX_INSUFFICIENT_ENTROPY: Insufficient entropy in RNG.
77
+
* @SGX_NO_UPDATE: EUPDATESVN could not update the CPUSVN because the
78
+
* current SVN was not newer than CPUSVN. This is the most
79
+
* common error code returned by EUPDATESVN.
80
+
* @SGX_UNMASKED_EVENT: An unmasked event, e.g. INTR, was received
78
81
*/
79
82
enum sgx_return_code {
80
83
SGX_EPC_PAGE_CONFLICT = 7,
···
86
81
SGX_CHILD_PRESENT = 13,
87
82
SGX_INVALID_EINITTOKEN = 16,
88
83
SGX_PAGE_NOT_MODIFIABLE = 20,
84
+
SGX_INSUFFICIENT_ENTROPY = 29,
85
+
SGX_NO_UPDATE = 31,
89
86
SGX_UNMASKED_EVENT = 128,
90
87
};
91
88
···
96
89
97
90
/**
98
91
* enum sgx_miscselect - additional information to an SSA frame
99
-
* %SGX_MISC_EXINFO: Report #PF or #GP to the SSA frame.
92
+
* @SGX_MISC_EXINFO: Report #PF or #GP to the SSA frame.
100
93
*
101
94
* Save State Area (SSA) is a stack inside the enclave used to store processor
102
95
* state when an exception or interrupt occurs. This enum defines additional
···
112
105
#define SGX_SSA_MISC_EXINFO_SIZE 16
113
106
114
107
/**
115
-
* enum sgx_attributes - 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
108
+
* enum sgx_attribute - 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
120
113
* 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
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
123
116
* sign cryptographic tokens that can be passed to
124
117
* EINIT as an authorization to run an enclave.
125
-
* %SGX_ATTR_ASYNC_EXIT_NOTIFY: Allow enclaves to be notified after an
118
+
* @SGX_ATTR_ASYNC_EXIT_NOTIFY: Allow enclaves to be notified after an
126
119
* asynchronous exit has occurred.
127
120
*/
128
121
enum sgx_attribute {
···
195
188
196
189
/**
197
190
* enum sgx_tcs_flags - execution flags for TCS
198
-
* %SGX_TCS_DBGOPTIN: If enabled allows single-stepping and breakpoints
191
+
* @SGX_TCS_DBGOPTIN: If enabled allows single-stepping and breakpoints
199
192
* inside an enclave. It is cleared by EADD but can
200
193
* be set later with EDBGWR.
201
194
*/
···
260
253
261
254
/**
262
255
* 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
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
268
261
*
269
262
* Make sure when making changes to this enum that its values can still fit
270
263
* in the bitfield within &struct sgx_encl_page
···
282
275
283
276
/**
284
277
* 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
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
293
286
*/
294
287
enum sgx_secinfo_flags {
295
288
SGX_SECINFO_R = BIT(0),
+8
-2
arch/x86/include/uapi/asm/sgx.h
+8
-2
arch/x86/include/uapi/asm/sgx.h
···
10
10
11
11
/**
12
12
* enum sgx_page_flags - page control flags
13
-
* %SGX_PAGE_MEASURE: Measure the page contents with a sequence of
13
+
* @SGX_PAGE_MEASURE: Measure the page contents with a sequence of
14
14
* ENCLS[EEXTEND] operations.
15
15
*/
16
16
enum sgx_page_flags {
···
143
143
/**
144
144
* typedef sgx_enclave_user_handler_t - Exit handler function accepted by
145
145
* __vdso_sgx_enter_enclave()
146
+
* @rdi: RDI at the time of EEXIT, undefined on AEX
147
+
* @rsi: RSI at the time of EEXIT, undefined on AEX
148
+
* @rdx: RDX at the time of EEXIT, undefined on AEX
149
+
* @rsp: RSP (untrusted) at the time of EEXIT or AEX
150
+
* @r8: R8 at the time of EEXIT, undefined on AEX
151
+
* @r9: R9 at the time of EEXIT, undefined on AEX
146
152
* @run: The run instance given by the caller
147
153
*
148
154
* The register parameters contain the snapshot of their values at enclave
···
172
166
* @exception_addr: The address that triggered the exception
173
167
* @user_handler: User provided callback run on exception
174
168
* @user_data: Data passed to the user handler
175
-
* @reserved Reserved for future extensions
169
+
* @reserved: Reserved for future extensions
176
170
*
177
171
* If @user_handler is provided, the handler will be invoked on all return paths
178
172
* of the normal flow. The user handler may transfer control, e.g. via a
+1
arch/x86/kernel/cpu/cpuid-deps.c
+1
arch/x86/kernel/cpu/cpuid-deps.c
···
80
80
{ X86_FEATURE_SGX_LC, X86_FEATURE_SGX },
81
81
{ X86_FEATURE_SGX1, X86_FEATURE_SGX },
82
82
{ X86_FEATURE_SGX2, X86_FEATURE_SGX1 },
83
+
{ X86_FEATURE_SGX_EUPDATESVN, X86_FEATURE_SGX1 },
83
84
{ X86_FEATURE_SGX_EDECCSSA, X86_FEATURE_SGX1 },
84
85
{ X86_FEATURE_XFD, X86_FEATURE_XSAVES },
85
86
{ X86_FEATURE_XFD, X86_FEATURE_XGETBV1 },
+1
arch/x86/kernel/cpu/scattered.c
+1
arch/x86/kernel/cpu/scattered.c
···
43
43
{ X86_FEATURE_PER_THREAD_MBA, CPUID_ECX, 0, 0x00000010, 3 },
44
44
{ X86_FEATURE_SGX1, CPUID_EAX, 0, 0x00000012, 0 },
45
45
{ X86_FEATURE_SGX2, CPUID_EAX, 1, 0x00000012, 0 },
46
+
{ X86_FEATURE_SGX_EUPDATESVN, CPUID_EAX, 10, 0x00000012, 0 },
46
47
{ X86_FEATURE_SGX_EDECCSSA, CPUID_EAX, 11, 0x00000012, 0 },
47
48
{ X86_FEATURE_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 },
48
49
{ X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 },
+18
-1
arch/x86/kernel/cpu/sgx/driver.c
+18
-1
arch/x86/kernel/cpu/sgx/driver.c
···
14
14
u64 sgx_xfrm_reserved_mask = ~0x3;
15
15
u32 sgx_misc_reserved_mask;
16
16
17
-
static int sgx_open(struct inode *inode, struct file *file)
17
+
static int __sgx_open(struct inode *inode, struct file *file)
18
18
{
19
19
struct sgx_encl *encl;
20
20
int ret;
···
37
37
}
38
38
39
39
file->private_data = encl;
40
+
41
+
return 0;
42
+
}
43
+
44
+
static int sgx_open(struct inode *inode, struct file *file)
45
+
{
46
+
int ret;
47
+
48
+
ret = sgx_inc_usage_count();
49
+
if (ret)
50
+
return ret;
51
+
52
+
ret = __sgx_open(inode, file);
53
+
if (ret) {
54
+
sgx_dec_usage_count();
55
+
return ret;
56
+
}
40
57
41
58
return 0;
42
59
}
+1
arch/x86/kernel/cpu/sgx/encl.c
+1
arch/x86/kernel/cpu/sgx/encl.c
+5
arch/x86/kernel/cpu/sgx/encls.h
+5
arch/x86/kernel/cpu/sgx/encls.h
+101
arch/x86/kernel/cpu/sgx/main.c
+101
arch/x86/kernel/cpu/sgx/main.c
···
16
16
#include <linux/vmalloc.h>
17
17
#include <asm/msr.h>
18
18
#include <asm/sgx.h>
19
+
#include <asm/archrandom.h>
19
20
#include "driver.h"
20
21
#include "encl.h"
21
22
#include "encls.h"
···
917
916
return 0;
918
917
}
919
918
EXPORT_SYMBOL_GPL(sgx_set_attribute);
919
+
920
+
/* Counter to count the active SGX users */
921
+
static int sgx_usage_count;
922
+
923
+
/**
924
+
* sgx_update_svn() - Attempt to call ENCLS[EUPDATESVN].
925
+
*
926
+
* This instruction attempts to update CPUSVN to the
927
+
* currently loaded microcode update SVN and generate new
928
+
* cryptographic assets.
929
+
*
930
+
* Return:
931
+
* * %0: - Success or not supported
932
+
* * %-EAGAIN: - Can be safely retried, failure is due to lack of
933
+
* * entropy in RNG
934
+
* * %-EIO: - Unexpected error, retries are not advisable
935
+
*/
936
+
static int sgx_update_svn(void)
937
+
{
938
+
int ret;
939
+
940
+
/*
941
+
* If EUPDATESVN is not available, it is ok to
942
+
* silently skip it to comply with legacy behavior.
943
+
*/
944
+
if (!cpu_feature_enabled(X86_FEATURE_SGX_EUPDATESVN))
945
+
return 0;
946
+
947
+
/*
948
+
* EPC is guaranteed to be empty when there are no users.
949
+
* Ensure we are on our first user before proceeding further.
950
+
*/
951
+
WARN(sgx_usage_count, "Elevated usage count when calling EUPDATESVN\n");
952
+
953
+
for (int i = 0; i < RDRAND_RETRY_LOOPS; i++) {
954
+
ret = __eupdatesvn();
955
+
956
+
/* Stop on success or unexpected errors: */
957
+
if (ret != SGX_INSUFFICIENT_ENTROPY)
958
+
break;
959
+
}
960
+
961
+
switch (ret) {
962
+
case 0:
963
+
/*
964
+
* SVN successfully updated.
965
+
* Let users know when the update was successful.
966
+
*/
967
+
pr_info("SVN updated successfully\n");
968
+
return 0;
969
+
case SGX_NO_UPDATE:
970
+
/*
971
+
* SVN update failed since the current SVN is
972
+
* not newer than CPUSVN. This is the most
973
+
* common case and indicates no harm.
974
+
*/
975
+
return 0;
976
+
case SGX_INSUFFICIENT_ENTROPY:
977
+
/*
978
+
* SVN update failed due to lack of entropy in DRNG.
979
+
* Indicate to userspace that it should retry.
980
+
*/
981
+
return -EAGAIN;
982
+
default:
983
+
break;
984
+
}
985
+
986
+
/*
987
+
* EUPDATESVN was called when EPC is empty, all other error
988
+
* codes are unexpected.
989
+
*/
990
+
ENCLS_WARN(ret, "EUPDATESVN");
991
+
return -EIO;
992
+
}
993
+
994
+
/* Mutex to ensure no concurrent EPC accesses during EUPDATESVN */
995
+
static DEFINE_MUTEX(sgx_svn_lock);
996
+
997
+
int sgx_inc_usage_count(void)
998
+
{
999
+
int ret;
1000
+
1001
+
guard(mutex)(&sgx_svn_lock);
1002
+
1003
+
if (!sgx_usage_count) {
1004
+
ret = sgx_update_svn();
1005
+
if (ret)
1006
+
return ret;
1007
+
}
1008
+
1009
+
sgx_usage_count++;
1010
+
1011
+
return 0;
1012
+
}
1013
+
1014
+
void sgx_dec_usage_count(void)
1015
+
{
1016
+
guard(mutex)(&sgx_svn_lock);
1017
+
sgx_usage_count--;
1018
+
}
920
1019
921
1020
static int __init sgx_init(void)
922
1021
{
+3
arch/x86/kernel/cpu/sgx/sgx.h
+3
arch/x86/kernel/cpu/sgx/sgx.h
+19
-1
arch/x86/kernel/cpu/sgx/virt.c
+19
-1
arch/x86/kernel/cpu/sgx/virt.c
···
255
255
xa_destroy(&vepc->page_array);
256
256
kfree(vepc);
257
257
258
+
sgx_dec_usage_count();
258
259
return 0;
259
260
}
260
261
261
-
static int sgx_vepc_open(struct inode *inode, struct file *file)
262
+
static int __sgx_vepc_open(struct inode *inode, struct file *file)
262
263
{
263
264
struct sgx_vepc *vepc;
264
265
···
270
269
xa_init(&vepc->page_array);
271
270
272
271
file->private_data = vepc;
272
+
273
+
return 0;
274
+
}
275
+
276
+
static int sgx_vepc_open(struct inode *inode, struct file *file)
277
+
{
278
+
int ret;
279
+
280
+
ret = sgx_inc_usage_count();
281
+
if (ret)
282
+
return ret;
283
+
284
+
ret = __sgx_vepc_open(inode, file);
285
+
if (ret) {
286
+
sgx_dec_usage_count();
287
+
return ret;
288
+
}
273
289
274
290
return 0;
275
291
}