FD.io VPP  v18.07-34-g55fbdb9
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 <svm/ssvm.h>
16 #include <svm/svm_common.h>
17 
18 typedef int (*init_fn) (ssvm_private_t *);
19 typedef void (*delete_fn) (ssvm_private_t *);
20 
27 
28 int
30 {
31  int ssvm_fd, mh_flags = MHEAP_FLAG_DISABLE_VM | MHEAP_FLAG_THREAD_SAFE;
32  clib_mem_vm_map_t mapa = { 0 };
33  u8 junk = 0, *ssvm_filename;
35  uword page_size, requested_va = 0;
36  void *oldheap;
37 
38  if (ssvm->ssvm_size == 0)
39  return SSVM_API_ERROR_NO_SIZE;
40 
41  if (CLIB_DEBUG > 1)
42  clib_warning ("[%d] creating segment '%s'", getpid (), ssvm->name);
43 
45  ssvm_filename = format (0, "/dev/shm/%s%c", ssvm->name, 0);
46  unlink ((char *) ssvm_filename);
47  vec_free (ssvm_filename);
48 
49  ssvm_fd = shm_open ((char *) ssvm->name, O_RDWR | O_CREAT | O_EXCL, 0777);
50  if (ssvm_fd < 0)
51  {
52  clib_unix_warning ("create segment '%s'", ssvm->name);
53  return SSVM_API_ERROR_CREATE_FAILURE;
54  }
55 
56  if (fchmod (ssvm_fd, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP) < 0)
57  clib_unix_warning ("ssvm segment chmod");
58  if (svm_get_root_rp ())
59  {
60  /* TODO: is this really needed? */
62  if (fchown (ssvm_fd, smr->uid, smr->gid) < 0)
63  clib_unix_warning ("ssvm segment chown");
64  }
65 
66  if (lseek (ssvm_fd, ssvm->ssvm_size, SEEK_SET) < 0)
67  {
68  clib_unix_warning ("lseek");
69  close (ssvm_fd);
70  return SSVM_API_ERROR_SET_SIZE;
71  }
72 
73  if (write (ssvm_fd, &junk, 1) != 1)
74  {
75  clib_unix_warning ("set ssvm size");
76  close (ssvm_fd);
77  return SSVM_API_ERROR_SET_SIZE;
78  }
79 
80  page_size = clib_mem_vm_get_page_size (ssvm_fd);
81  if (ssvm->requested_va)
82  {
83  requested_va = ssvm->requested_va;
84  clib_mem_vm_randomize_va (&requested_va, min_log2 (page_size));
85  }
86 
87  mapa.requested_va = requested_va;
88  mapa.size = ssvm->ssvm_size;
89  mapa.fd = ssvm_fd;
90  if (clib_mem_vm_ext_map (&mapa))
91  {
92  clib_unix_warning ("mmap");
93  close (ssvm_fd);
94  return SSVM_API_ERROR_MMAP;
95  }
96  close (ssvm_fd);
97 
98  sh = mapa.addr;
99  sh->master_pid = ssvm->my_pid;
100  sh->ssvm_size = ssvm->ssvm_size;
101  sh->ssvm_va = pointer_to_uword (sh);
102  sh->type = SSVM_SEGMENT_SHM;
103  sh->heap = mheap_alloc_with_flags (((u8 *) sh) + page_size,
104  ssvm->ssvm_size - page_size, mh_flags);
105 
106  oldheap = ssvm_push_heap (sh);
107  sh->name = format (0, "%s", ssvm->name, 0);
108  ssvm_pop_heap (oldheap);
109 
110  ssvm->sh = sh;
111  ssvm->my_pid = getpid ();
112  ssvm->i_am_master = 1;
113 
114  /* The application has to set set sh->ready... */
115  return 0;
116 }
117 
118 int
120 {
121  struct stat stat;
122  int ssvm_fd = -1;
124 
126  ssvm->i_am_master = 0;
127 
128  while (ssvm->attach_timeout-- > 0)
129  {
130  if (ssvm_fd < 0)
131  ssvm_fd = shm_open ((char *) ssvm->name, O_RDWR, 0777);
132  if (ssvm_fd < 0)
133  {
134  sleep (1);
135  continue;
136  }
137  if (fstat (ssvm_fd, &stat) < 0)
138  {
139  sleep (1);
140  continue;
141  }
142 
143  if (stat.st_size > 0)
144  goto map_it;
145  }
146  clib_warning ("slave timeout");
147  return SSVM_API_ERROR_SLAVE_TIMEOUT;
148 
149 map_it:
150  sh = (void *) mmap (0, MMAP_PAGESIZE, PROT_READ | PROT_WRITE, MAP_SHARED,
151  ssvm_fd, 0);
152  if (sh == MAP_FAILED)
153  {
154  clib_unix_warning ("slave research mmap");
155  close (ssvm_fd);
156  return SSVM_API_ERROR_MMAP;
157  }
158 
159  while (ssvm->attach_timeout-- > 0)
160  {
161  if (sh->ready)
162  goto re_map_it;
163  }
164  close (ssvm_fd);
165  munmap (sh, MMAP_PAGESIZE);
166  clib_warning ("slave timeout 2");
167  return SSVM_API_ERROR_SLAVE_TIMEOUT;
168 
169 re_map_it:
170  ssvm->requested_va = (u64) sh->ssvm_va;
171  ssvm->ssvm_size = sh->ssvm_size;
172  munmap (sh, MMAP_PAGESIZE);
173 
174  sh = ssvm->sh = (void *) mmap ((void *) ssvm->requested_va, ssvm->ssvm_size,
175  PROT_READ | PROT_WRITE,
176  MAP_SHARED | MAP_FIXED, ssvm_fd, 0);
177 
178  if (sh == MAP_FAILED)
179  {
180  clib_unix_warning ("slave final mmap");
181  close (ssvm_fd);
182  return SSVM_API_ERROR_MMAP;
183  }
184  sh->slave_pid = getpid ();
185  return 0;
186 }
187 
188 void
190 {
191  u8 *fn;
192 
193  fn = format (0, "/dev/shm/%s%c", ssvm->name, 0);
194 
195  if (CLIB_DEBUG > 1)
196  clib_warning ("[%d] unlinking ssvm (%s) backing file '%s'", getpid (),
197  ssvm->name, fn);
198 
199  /* Throw away the backing file */
200  if (unlink ((char *) fn) < 0)
201  clib_unix_warning ("unlink segment '%s'", ssvm->name);
202 
203  vec_free (fn);
204  vec_free (ssvm->name);
205 
206  munmap ((void *) ssvm->requested_va, ssvm->ssvm_size);
207 }
208 
209 /**
210  * Initialize memfd segment master
211  */
212 int
214 {
217  void *oldheap;
218  clib_mem_vm_alloc_t alloc = { 0 };
219  clib_error_t *err;
220 
221  if (memfd->ssvm_size == 0)
222  return SSVM_API_ERROR_NO_SIZE;
223 
225 
226  alloc.name = (char *) memfd->name;
227  alloc.size = memfd->ssvm_size;
228  alloc.flags = CLIB_MEM_VM_F_SHARED;
229  alloc.requested_va = memfd->requested_va;
230  if ((err = clib_mem_vm_ext_alloc (&alloc)))
231  {
232  clib_error_report (err);
233  return SSVM_API_ERROR_CREATE_FAILURE;
234  }
235 
236  memfd->fd = alloc.fd;
237  memfd->sh = (ssvm_shared_header_t *) alloc.addr;
238  memfd->my_pid = getpid ();
239  memfd->i_am_master = 1;
240 
241  page_size = 1 << alloc.log2_page_size;
242  sh = memfd->sh;
243  sh->master_pid = memfd->my_pid;
244  sh->ssvm_size = memfd->ssvm_size;
245  sh->ssvm_va = pointer_to_uword (sh);
246  sh->type = SSVM_SEGMENT_MEMFD;
247  sh->heap = mheap_alloc_with_flags (((u8 *) sh) + page_size,
248  memfd->ssvm_size - page_size, flags);
249 
250  oldheap = ssvm_push_heap (sh);
251  sh->name = format (0, "%s", memfd->name, 0);
252  ssvm_pop_heap (oldheap);
253 
254  /* The application has to set set sh->ready... */
255  return 0;
256 }
257 
258 /**
259  * Initialize memfd segment slave
260  *
261  * Subtly different than svm_slave_init. The caller needs to acquire
262  * a usable file descriptor for the memfd segment e.g. via
263  * vppinfra/socket.c:default_socket_recvmsg
264  */
265 int
267 {
268  clib_mem_vm_map_t mapa = { 0 };
270  uword page_size;
271 
272  memfd->i_am_master = 0;
273 
274  page_size = clib_mem_vm_get_page_size (memfd->fd);
275  if (!page_size)
276  {
277  clib_unix_warning ("page size unknown");
278  return SSVM_API_ERROR_MMAP;
279  }
280 
281  /*
282  * Map the segment once, to look at the shared header
283  */
284  mapa.fd = memfd->fd;
285  mapa.size = page_size;
286 
287  if (clib_mem_vm_ext_map (&mapa))
288  {
289  clib_unix_warning ("slave research mmap (fd %d)", mapa.fd);
290  close (memfd->fd);
291  return SSVM_API_ERROR_MMAP;
292  }
293 
294  sh = mapa.addr;
295  memfd->requested_va = sh->ssvm_va;
296  memfd->ssvm_size = sh->ssvm_size;
297  clib_mem_vm_free (sh, page_size);
298 
299  /*
300  * Remap the segment at the 'right' address
301  */
302  mapa.requested_va = memfd->requested_va;
303  mapa.size = memfd->ssvm_size;
304  if (clib_mem_vm_ext_map (&mapa))
305  {
306  clib_unix_warning ("slave final mmap");
307  close (memfd->fd);
308  return SSVM_API_ERROR_MMAP;
309  }
310 
311  sh = mapa.addr;
312  sh->slave_pid = getpid ();
313  memfd->sh = sh;
314  return 0;
315 }
316 
317 void
319 {
320  vec_free (memfd->name);
321  clib_mem_vm_free (memfd->sh, memfd->ssvm_size);
322  close (memfd->fd);
323 }
324 
325 /**
326  * Initialize segment in a private heap
327  */
328 int
330 {
331  u32 pagesize = clib_mem_get_page_size ();
334  u32 rnd_size = 0;
335  u8 *heap;
336 
337  rnd_size = (ssvm->ssvm_size + (pagesize - 1)) & ~pagesize;
338  heap = mheap_alloc (0, rnd_size);
339  if (heap == 0)
340  {
341  clib_unix_warning ("mheap alloc");
342  return -1;
343  }
344  heap_header = mheap_header (heap);
345  heap_header->flags |= MHEAP_FLAG_THREAD_SAFE;
346 
347  ssvm->ssvm_size = rnd_size;
348  ssvm->i_am_master = 1;
349  ssvm->my_pid = getpid ();
350  ssvm->requested_va = ~0;
351 
352  /* Allocate a [sic] shared memory header, in process memory... */
353  sh = clib_mem_alloc_aligned (sizeof (*sh), CLIB_CACHE_LINE_BYTES);
354  ssvm->sh = sh;
355 
356  memset (sh, 0, sizeof (*sh));
357  sh->heap = heap;
359 
360  return 0;
361 }
362 
363 int
365 {
366  clib_warning ("BUG: this should not be called!");
367  return -1;
368 }
369 
370 void
372 {
373  vec_free (ssvm->name);
374  mheap_free (ssvm->sh->heap);
375  clib_mem_free (ssvm->sh);
376 }
377 
378 int
380 {
381  return (master_init_fns[type]) (ssvm);
382 }
383 
384 int
386 {
387  return (slave_init_fns[type]) (ssvm);
388 }
389 
390 void
392 {
393  delete_fns[ssvm->sh->type] (ssvm);
394 }
395 
397 ssvm_type (const ssvm_private_t * ssvm)
398 {
399  return ssvm->sh->type;
400 }
401 
402 u8 *
403 ssvm_name (const ssvm_private_t * ssvm)
404 {
405  return ssvm->sh->name;
406 }
407 
408 /*
409  * fd.io coding-style-patch-verification: ON
410  *
411  * Local Variables:
412  * eval: (c-set-style "gnu")
413  * End:
414  */
u64 ssvm_size
Definition: ssvm.h:84
svm_region_t * svm_get_root_rp(void)
Definition: svm.c:54
static init_fn slave_init_fns[SSVM_N_SEGMENT_TYPES]
Definition: ssvm.c:23
static init_fn master_init_fns[SSVM_N_SEGMENT_TYPES]
Definition: ssvm.c:21
uword requested_va
Definition: ssvm.h:87
#define vec_c_string_is_terminated(V)
Test whether a vector is a NULL terminated c-string.
Definition: vec.h:1008
volatile u32 ready
Definition: ssvm.h:76
unsigned long u64
Definition: types.h:89
void * mheap_alloc(void *memory, uword size)
Definition: mheap.c:963
ssvm_segment_type_t type
Definition: ssvm.h:78
void * addr
Pointer to allocated memory, set on successful allocation.
Definition: mem.h:346
uword requested_va
Request fixed position mapping.
Definition: mem.h:350
void(* delete_fn)(ssvm_private_t *)
Definition: ssvm.c:19
static mheap_t * mheap_header(u8 *v)
int ssvm_slave_init_shm(ssvm_private_t *ssvm)
Definition: ssvm.c:119
ssvm_shared_header_t * sh
Definition: ssvm.h:83
u8 * format(u8 *s, const char *fmt,...)
Definition: format.c:419
#define MHEAP_FLAG_THREAD_SAFE
int ssvm_master_init_shm(ssvm_private_t *ssvm)
Definition: ssvm.c:29
unsigned char u8
Definition: types.h:56
static uword min_log2(uword x)
Definition: clib.h:138
void ssvm_delete(ssvm_private_t *ssvm)
Definition: ssvm.c:391
int ssvm_slave_init_private(ssvm_private_t *ssvm)
Definition: ssvm.c:364
u8 * ssvm_name(const ssvm_private_t *ssvm)
Definition: ssvm.c:403
enum ssvm_segment_type_ ssvm_segment_type_t
clib_error_t * clib_mem_vm_ext_map(clib_mem_vm_map_t *a)
Definition: mem.c:295
clib_error_t * clib_mem_vm_ext_alloc(clib_mem_vm_alloc_t *a)
Definition: mem.c:80
uword requested_va
Request fixed position mapping.
Definition: mem.h:362
int(* init_fn)(ssvm_private_t *)
Definition: ssvm.c:18
#define MHEAP_FLAG_DISABLE_VM
int ssvm_master_init_memfd(ssvm_private_t *memfd)
Initialize memfd segment master.
Definition: ssvm.c:213
char * name
Name for memory allocation, set by caller.
Definition: mem.h:343
static void * ssvm_push_heap(ssvm_shared_header_t *sh)
Definition: ssvm.h:144
uword size
Allocation size, set by caller.
Definition: mem.h:344
unsigned int u32
Definition: types.h:88
int attach_timeout
shm segments attach timeout (sec)
Definition: ssvm.h:93
#define mheap_free(v)
Definition: mheap.h:62
int ssvm_master_init(ssvm_private_t *ssvm, ssvm_segment_type_t type)
Definition: ssvm.c:379
static void ssvm_pop_heap(void *oldheap)
Definition: ssvm.h:152
#define CLIB_MEM_VM_F_SHARED
Definition: mem.h:326
void * data_base
Definition: svm_common.h:45
int fd
File descriptor, set on successful allocation if CLIB_MEM_VM_F_SHARED is set.
Definition: mem.h:347
uword clib_mem_vm_get_page_size(int fd)
Definition: mem.c:50
u32 flags
Definition: vhost_user.h:110
#define vec_free(V)
Free vector&#39;s memory (no header).
Definition: vec.h:339
#define clib_warning(format, args...)
Definition: error.h:59
int ssvm_slave_init(ssvm_private_t *ssvm, ssvm_segment_type_t type)
Definition: ssvm.c:385
u32 my_pid
Definition: ssvm.h:85
u32 flags
vm allocation flags: CLIB_MEM_VM_F_SHARED: request shared memory, file descriptor will be provided ...
Definition: mem.h:332
int fd
memfd segments
Definition: ssvm.h:92
void * mheap_alloc_with_flags(void *memory, uword memory_size, uword flags)
Definition: mheap.c:885
#define ASSERT(truth)
uword size
Map size.
Definition: mem.h:360
static void clib_mem_free(void *p)
Definition: mem.h:179
#define clib_error_report(e)
Definition: error.h:113
static heap_header_t * heap_header(void *v)
Definition: heap.h:161
static uword pointer_to_uword(const void *p)
Definition: types.h:131
u8 * name
Definition: ssvm.h:86
#define MMAP_PAGESIZE
Definition: ssvm.h:42
static void clib_mem_vm_free(void *addr, uword size)
Definition: mem.h:289
u64 uword
Definition: types.h:112
static delete_fn delete_fns[SSVM_N_SEGMENT_TYPES]
Definition: ssvm.c:25
#define clib_unix_warning(format, args...)
Definition: error.h:68
void ssvm_delete_memfd(ssvm_private_t *memfd)
Definition: ssvm.c:318
void clib_mem_vm_randomize_va(uword *requested_va, u32 log2_page_size)
Definition: mem.c:65
int ssvm_master_init_private(ssvm_private_t *ssvm)
Initialize segment in a private heap.
Definition: ssvm.c:329
static void * clib_mem_alloc_aligned(uword size, uword align)
Definition: mem.h:120
int fd
File descriptor to be mapped.
Definition: mem.h:361
void ssvm_delete_private(ssvm_private_t *ssvm)
Definition: ssvm.c:371
void ssvm_delete_shm(ssvm_private_t *ssvm)
Definition: ssvm.c:189
int log2_page_size
Definition: mem.h:348
#define CLIB_CACHE_LINE_BYTES
Definition: cache.h:62
Private segments.
Definition: ssvm.h:52
uword clib_mem_get_page_size(void)
Definition: mem_mheap.c:110
int i_am_master
Definition: ssvm.h:88
int ssvm_slave_init_memfd(ssvm_private_t *memfd)
Initialize memfd segment slave.
Definition: ssvm.c:266
void * addr
Pointer to mapped memory, if successful.
Definition: mem.h:363
ssvm_segment_type_t ssvm_type(const ssvm_private_t *ssvm)
Definition: ssvm.c:397