1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
/**********************************************************************
Copyright(c) 2018 Intel Corporation All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
* Neither the name of Intel Corporation nor the names of its
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**********************************************************************/
/**
* @brief Provides access to MSR read & write operations
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef _WIN32
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#endif
#include "msr.h"
static int *m_msr_fd = NULL; /**< MSR driver file descriptors table */
static unsigned m_maxcores = 0; /**< max number of cores (size of the
table above too) */
int
machine_init(const unsigned max_core_id)
{
#ifndef _WIN32
unsigned i;
if (max_core_id == 0)
return MACHINE_RETVAL_PARAM;
m_maxcores = max_core_id + 1;
/**
* Allocate table to hold MSR driver file descriptors
* Each file descriptor is for a different core.
* Core id is an index to the table.
*/
m_msr_fd = (int *)malloc(m_maxcores * sizeof(m_msr_fd[0]));
if (m_msr_fd == NULL) {
m_maxcores = 0;
return MACHINE_RETVAL_ERROR;
}
for (i = 0; i < m_maxcores; i++)
m_msr_fd[i] = -1;
#endif /* _WIN32 */
return MACHINE_RETVAL_OK;
}
int
machine_fini(void)
{
#ifndef _WIN32
unsigned i;
ASSERT(m_msr_fd != NULL);
if (m_msr_fd == NULL)
return MACHINE_RETVAL_ERROR;
/**
* Close open file descriptors and free up table memory.
*/
for (i = 0; i < m_maxcores; i++)
if (m_msr_fd[i] != -1) {
close(m_msr_fd[i]);
m_msr_fd[i] = -1;
}
free(m_msr_fd);
m_msr_fd = NULL;
m_maxcores = 0;
#endif /* _WIN32 */
return MACHINE_RETVAL_OK;
}
#ifndef _WIN32
/**
* @brief Returns MSR driver file descriptor for given core id
*
* File descriptor could be previously open and comes from
* m_msr_fd table or is open (& cached) during the call.
*
* @param lcore logical core id
*
* @return MSR driver file descriptor corresponding \a lcore
*/
static int
msr_file_open(const unsigned lcore)
{
ASSERT(lcore < m_maxcores);
ASSERT(m_msr_fd != NULL);
int fd = m_msr_fd[lcore];
if (fd < 0) {
char fname[32];
memset(fname, 0, sizeof(fname));
snprintf(fname, sizeof(fname)-1,
"/dev/cpu/%u/msr", lcore);
fd = open(fname, O_RDWR);
if (fd < 0)
fprintf(stderr, "Error opening file '%s'!\n", fname);
else
m_msr_fd[lcore] = fd;
}
return fd;
}
#endif /* _WIN32 */
int
msr_read(const unsigned lcore,
const uint32_t reg,
uint64_t *value)
{
int ret = MACHINE_RETVAL_OK;
#ifndef _WIN32
int fd = -1;
ssize_t read_ret = 0;
ASSERT(value != NULL);
if (value == NULL)
return MACHINE_RETVAL_PARAM;
ASSERT(lcore < m_maxcores);
if (lcore >= m_maxcores)
return MACHINE_RETVAL_PARAM;
ASSERT(m_msr_fd != NULL);
if (m_msr_fd == NULL)
return MACHINE_RETVAL_ERROR;
fd = msr_file_open(lcore);
if (fd < 0)
return MACHINE_RETVAL_ERROR;
read_ret = pread(fd, value, sizeof(value[0]), (off_t)reg);
if (read_ret != sizeof(value[0])) {
fprintf(stderr, "RDMSR failed for reg[0x%x] on lcore %u\n",
(unsigned)reg, lcore);
ret = MACHINE_RETVAL_ERROR;
}
#endif /* _WIN32 */
return ret;
}
int
msr_write(const unsigned lcore,
const uint32_t reg,
const uint64_t value)
{
int ret = MACHINE_RETVAL_OK;
#ifndef _WIN32
int fd = -1;
ssize_t write_ret = 0;
ASSERT(lcore < m_maxcores);
if (lcore >= m_maxcores)
return MACHINE_RETVAL_PARAM;
ASSERT(m_msr_fd != NULL);
if (m_msr_fd == NULL)
return MACHINE_RETVAL_ERROR;
fd = msr_file_open(lcore);
if (fd < 0)
return MACHINE_RETVAL_ERROR;
write_ret = pwrite(fd, &value, sizeof(value), (off_t)reg);
if (write_ret != sizeof(value)) {
fprintf(stderr, "WRMSR failed for reg[0x%x] "
"<- value[0x%llx] on lcore %u\n",
(unsigned)reg, (unsigned long long)value, lcore);
ret = MACHINE_RETVAL_ERROR;
}
#endif /* _WIN32 */
return ret;
}
|
