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Vector Packet Processing
ssvm.c
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1 /*
2  * Copyright (c) 2015 Cisco and/or its affiliates.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 #include "ssvm.h"
16 #include "svm_common.h"
17 
18 int
19 ssvm_master_init (ssvm_private_t * ssvm, u32 master_index)
20 {
22  int ssvm_fd;
23  u8 *ssvm_filename;
24  u8 junk = 0;
25  int flags;
27  u64 ticks = clib_cpu_time_now ();
28  u64 randomize_baseva;
29  void *oldheap;
30 
31  if (ssvm->ssvm_size == 0)
32  return SSVM_API_ERROR_NO_SIZE;
33 
34  if (CLIB_DEBUG > 1)
35  clib_warning ("[%d] creating segment '%s'", getpid (), ssvm->name);
36 
38  ssvm_filename = format (0, "/dev/shm/%s%c", ssvm->name, 0);
39 
40  unlink ((char *) ssvm_filename);
41 
42  vec_free (ssvm_filename);
43 
44  ssvm_fd = shm_open ((char *) ssvm->name, O_RDWR | O_CREAT | O_EXCL, 0777);
45 
46  if (ssvm_fd < 0)
47  {
48  clib_unix_warning ("create segment '%s'", ssvm->name);
49  return SSVM_API_ERROR_CREATE_FAILURE;
50  }
51 
52  if (fchmod (ssvm_fd, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP) < 0)
53  clib_unix_warning ("ssvm segment chmod");
54  if (fchown (ssvm_fd, smr->uid, smr->gid) < 0)
55  clib_unix_warning ("ssvm segment chown");
56 
57  if (lseek (ssvm_fd, ssvm->ssvm_size, SEEK_SET) < 0)
58  {
59  clib_unix_warning ("lseek");
60  close (ssvm_fd);
61  return SSVM_API_ERROR_SET_SIZE;
62  }
63 
64  if (write (ssvm_fd, &junk, 1) != 1)
65  {
66  clib_unix_warning ("set ssvm size");
67  close (ssvm_fd);
68  return SSVM_API_ERROR_SET_SIZE;
69  }
70 
71  flags = MAP_SHARED;
72  if (ssvm->requested_va)
73  flags |= MAP_FIXED;
74 
75  randomize_baseva = (ticks & 15) * MMAP_PAGESIZE;
76 
77  if (ssvm->requested_va)
78  ssvm->requested_va += randomize_baseva;
79 
80  sh = ssvm->sh =
81  (ssvm_shared_header_t *) mmap ((void *) ssvm->requested_va,
82  ssvm->ssvm_size, PROT_READ | PROT_WRITE,
83  flags, ssvm_fd, 0);
84 
85  if (ssvm->sh == MAP_FAILED)
86  {
87  clib_unix_warning ("mmap");
88  close (ssvm_fd);
89  return SSVM_API_ERROR_MMAP;
90  }
91 
92  close (ssvm_fd);
93 
94  ssvm->my_pid = getpid ();
95  sh->master_pid = ssvm->my_pid;
96  sh->ssvm_size = ssvm->ssvm_size;
98  (((u8 *) sh) + MMAP_PAGESIZE, ssvm->ssvm_size - MMAP_PAGESIZE,
100 
101  sh->ssvm_va = pointer_to_uword (sh);
102  sh->master_index = master_index;
103 
104  oldheap = ssvm_push_heap (sh);
105  sh->name = format (0, "%s%c", ssvm->name, 0);
106  ssvm_pop_heap (oldheap);
107 
108  ssvm->i_am_master = 1;
109 
110  /* The application has to set set sh->ready... */
111  return 0;
112 }
113 
114 int
115 ssvm_slave_init (ssvm_private_t * ssvm, int timeout_in_seconds)
116 {
117  struct stat stat;
118  int ssvm_fd = -1;
120 
122  ssvm->i_am_master = 0;
123 
124  while (timeout_in_seconds-- > 0)
125  {
126  if (ssvm_fd < 0)
127  ssvm_fd = shm_open ((char *) ssvm->name, O_RDWR, 0777);
128  if (ssvm_fd < 0)
129  {
130  sleep (1);
131  continue;
132  }
133  if (fstat (ssvm_fd, &stat) < 0)
134  {
135  sleep (1);
136  continue;
137  }
138 
139  if (stat.st_size > 0)
140  goto map_it;
141  }
142  clib_warning ("slave timeout");
143  return SSVM_API_ERROR_SLAVE_TIMEOUT;
144 
145 map_it:
146  sh = (void *) mmap (0, MMAP_PAGESIZE, PROT_READ | PROT_WRITE, MAP_SHARED,
147  ssvm_fd, 0);
148  if (sh == MAP_FAILED)
149  {
150  clib_unix_warning ("slave research mmap");
151  close (ssvm_fd);
152  return SSVM_API_ERROR_MMAP;
153  }
154 
155  while (timeout_in_seconds-- > 0)
156  {
157  if (sh->ready)
158  goto re_map_it;
159  }
160  close (ssvm_fd);
161  munmap (sh, MMAP_PAGESIZE);
162  clib_warning ("slave timeout 2");
163  return SSVM_API_ERROR_SLAVE_TIMEOUT;
164 
165 re_map_it:
166  ssvm->requested_va = (u64) sh->ssvm_va;
167  ssvm->ssvm_size = sh->ssvm_size;
168  munmap (sh, MMAP_PAGESIZE);
169 
170  sh = ssvm->sh = (void *) mmap ((void *) ssvm->requested_va, ssvm->ssvm_size,
171  PROT_READ | PROT_WRITE,
172  MAP_SHARED | MAP_FIXED, ssvm_fd, 0);
173 
174  if (sh == MAP_FAILED)
175  {
176  clib_unix_warning ("slave final mmap");
177  close (ssvm_fd);
178  return SSVM_API_ERROR_MMAP;
179  }
180  sh->slave_pid = getpid ();
181  return 0;
182 }
183 
184 void
186 {
187  u8 *fn;
188 
189  fn = format (0, "/dev/shm/%s%c", ssvm->name, 0);
190 
191  if (CLIB_DEBUG > 1)
192  clib_warning ("[%d] unlinking ssvm (%s) backing file '%s'", getpid (),
193  ssvm->name, fn);
194 
195  /* Throw away the backing file */
196  if (unlink ((char *) fn) < 0)
197  clib_unix_warning ("unlink segment '%s'", ssvm->name);
198 
199  vec_free (fn);
200  vec_free (ssvm->name);
201 
202  munmap ((void *) ssvm->requested_va, ssvm->ssvm_size);
203 }
204 
205 
206 /*
207  * fd.io coding-style-patch-verification: ON
208  *
209  * Local Variables:
210  * eval: (c-set-style "gnu")
211  * End:
212  */
u64 ssvm_size
Definition: ssvm.h:77
svm_region_t * svm_get_root_rp(void)
Definition: svm.c:54
uword requested_va
Definition: ssvm.h:81
#define vec_c_string_is_terminated(V)
Test whether a vector is a NULL terminated c-string.
Definition: vec.h:982
int ssvm_master_init(ssvm_private_t *ssvm, u32 master_index)
Definition: ssvm.c:19
volatile u32 ready
Definition: ssvm.h:68
static u64 clib_cpu_time_now(void)
Definition: time.h:73
ssvm_shared_header_t * sh
Definition: ssvm.h:76
u8 * format(u8 *s, const char *fmt,...)
Definition: format.c:419
#define MHEAP_FLAG_THREAD_SAFE
void ssvm_delete(ssvm_private_t *ssvm)
Definition: ssvm.c:185
#define MMAP_PAGESIZE
Definition: memfd.h:44
#define MHEAP_FLAG_DISABLE_VM
static void * ssvm_push_heap(ssvm_shared_header_t *sh)
Definition: ssvm.h:134
unsigned long u64
Definition: types.h:89
static void ssvm_pop_heap(void *oldheap)
Definition: ssvm.h:142
static uword pointer_to_uword(const void *p)
Definition: types.h:131
void * data_base
Definition: svm_common.h:45
int ssvm_slave_init(ssvm_private_t *ssvm, int timeout_in_seconds)
Definition: ssvm.c:115
#define vec_free(V)
Free vector&#39;s memory (no header).
Definition: vec.h:336
#define clib_warning(format, args...)
Definition: error.h:59
u32 my_pid
Definition: ssvm.h:78
void * mheap_alloc_with_flags(void *memory, uword memory_size, uword flags)
Definition: mheap.c:869
#define ASSERT(truth)
unsigned int u32
Definition: types.h:88
u8 * name
Definition: ssvm.h:80
unsigned char u8
Definition: types.h:56
#define clib_unix_warning(format, args...)
Definition: error.h:68
u32 flags
Definition: vhost-user.h:77
int i_am_master
Definition: ssvm.h:82