Commit | Line | Data |
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416efba0 SS |
1 | /* |
2 | * (c) 2017 Stefano Stabellini <stefano@aporeto.com> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | */ | |
14 | ||
15 | #include <linux/module.h> | |
2195046b SS |
16 | #include <linux/net.h> |
17 | #include <linux/socket.h> | |
18 | ||
19 | #include <net/sock.h> | |
416efba0 SS |
20 | |
21 | #include <xen/events.h> | |
22 | #include <xen/grant_table.h> | |
23 | #include <xen/xen.h> | |
24 | #include <xen/xenbus.h> | |
25 | #include <xen/interface/io/pvcalls.h> | |
26 | ||
2195046b SS |
27 | #include "pvcalls-front.h" |
28 | ||
aa7ba376 SS |
29 | #define PVCALLS_INVALID_ID UINT_MAX |
30 | #define PVCALLS_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER | |
31 | #define PVCALLS_NR_RSP_PER_RING __CONST_RING_SIZE(xen_pvcalls, XEN_PAGE_SIZE) | |
45ddce21 | 32 | #define PVCALLS_FRONT_MAX_SPIN 5000 |
aa7ba376 | 33 | |
beee1fbe SS |
34 | static struct proto pvcalls_proto = { |
35 | .name = "PVCalls", | |
36 | .owner = THIS_MODULE, | |
37 | .obj_size = sizeof(struct sock), | |
38 | }; | |
39 | ||
aa7ba376 SS |
40 | struct pvcalls_bedata { |
41 | struct xen_pvcalls_front_ring ring; | |
42 | grant_ref_t ref; | |
43 | int irq; | |
44 | ||
45 | struct list_head socket_mappings; | |
46 | spinlock_t socket_lock; | |
47 | ||
48 | wait_queue_head_t inflight_req; | |
49 | struct xen_pvcalls_response rsp[PVCALLS_NR_RSP_PER_RING]; | |
50 | }; | |
51 | /* Only one front/back connection supported. */ | |
52 | static struct xenbus_device *pvcalls_front_dev; | |
53 | static atomic_t pvcalls_refcount; | |
54 | ||
55 | /* first increment refcount, then proceed */ | |
56 | #define pvcalls_enter() { \ | |
57 | atomic_inc(&pvcalls_refcount); \ | |
58 | } | |
59 | ||
60 | /* first complete other operations, then decrement refcount */ | |
61 | #define pvcalls_exit() { \ | |
62 | atomic_dec(&pvcalls_refcount); \ | |
63 | } | |
64 | ||
65 | struct sock_mapping { | |
66 | bool active_socket; | |
67 | struct list_head list; | |
68 | struct socket *sock; | |
64d68718 | 69 | atomic_t refcount; |
cb1c7d9b SS |
70 | union { |
71 | struct { | |
72 | int irq; | |
73 | grant_ref_t ref; | |
74 | struct pvcalls_data_intf *ring; | |
75 | struct pvcalls_data data; | |
76 | struct mutex in_mutex; | |
77 | struct mutex out_mutex; | |
78 | ||
79 | wait_queue_head_t inflight_conn_req; | |
80 | } active; | |
67ea9893 | 81 | struct { |
d811bcee SS |
82 | /* |
83 | * Socket status, needs to be 64-bit aligned due to the | |
84 | * test_and_* functions which have this requirement on arm64. | |
85 | */ | |
67ea9893 SS |
86 | #define PVCALLS_STATUS_UNINITALIZED 0 |
87 | #define PVCALLS_STATUS_BIND 1 | |
88 | #define PVCALLS_STATUS_LISTEN 2 | |
d811bcee | 89 | uint8_t status __attribute__((aligned(8))); |
9774c6cc SS |
90 | /* |
91 | * Internal state-machine flags. | |
92 | * Only one accept operation can be inflight for a socket. | |
93 | * Only one poll operation can be inflight for a given socket. | |
d811bcee SS |
94 | * flags needs to be 64-bit aligned due to the test_and_* |
95 | * functions which have this requirement on arm64. | |
9774c6cc SS |
96 | */ |
97 | #define PVCALLS_FLAG_ACCEPT_INFLIGHT 0 | |
5842c835 SS |
98 | #define PVCALLS_FLAG_POLL_INFLIGHT 1 |
99 | #define PVCALLS_FLAG_POLL_RET 2 | |
d811bcee | 100 | uint8_t flags __attribute__((aligned(8))); |
9774c6cc SS |
101 | uint32_t inflight_req_id; |
102 | struct sock_mapping *accept_map; | |
103 | wait_queue_head_t inflight_accept_req; | |
67ea9893 | 104 | } passive; |
cb1c7d9b | 105 | }; |
aa7ba376 SS |
106 | }; |
107 | ||
64d68718 SS |
108 | static inline struct sock_mapping *pvcalls_enter_sock(struct socket *sock) |
109 | { | |
110 | struct sock_mapping *map; | |
111 | ||
112 | if (!pvcalls_front_dev || | |
113 | dev_get_drvdata(&pvcalls_front_dev->dev) == NULL) | |
114 | return ERR_PTR(-ENOTCONN); | |
115 | ||
116 | map = (struct sock_mapping *)sock->sk->sk_send_head; | |
117 | if (map == NULL) | |
118 | return ERR_PTR(-ENOTSOCK); | |
119 | ||
120 | pvcalls_enter(); | |
121 | atomic_inc(&map->refcount); | |
122 | return map; | |
123 | } | |
124 | ||
125 | static inline void pvcalls_exit_sock(struct socket *sock) | |
126 | { | |
127 | struct sock_mapping *map; | |
128 | ||
129 | map = (struct sock_mapping *)sock->sk->sk_send_head; | |
130 | atomic_dec(&map->refcount); | |
131 | pvcalls_exit(); | |
132 | } | |
133 | ||
2195046b SS |
134 | static inline int get_request(struct pvcalls_bedata *bedata, int *req_id) |
135 | { | |
136 | *req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1); | |
137 | if (RING_FULL(&bedata->ring) || | |
138 | bedata->rsp[*req_id].req_id != PVCALLS_INVALID_ID) | |
139 | return -EAGAIN; | |
140 | return 0; | |
141 | } | |
142 | ||
45ddce21 SS |
143 | static bool pvcalls_front_write_todo(struct sock_mapping *map) |
144 | { | |
145 | struct pvcalls_data_intf *intf = map->active.ring; | |
146 | RING_IDX cons, prod, size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
147 | int32_t error; | |
148 | ||
149 | error = intf->out_error; | |
150 | if (error == -ENOTCONN) | |
151 | return false; | |
152 | if (error != 0) | |
153 | return true; | |
154 | ||
155 | cons = intf->out_cons; | |
156 | prod = intf->out_prod; | |
157 | return !!(size - pvcalls_queued(prod, cons, size)); | |
158 | } | |
159 | ||
ae0d0405 SS |
160 | static bool pvcalls_front_read_todo(struct sock_mapping *map) |
161 | { | |
162 | struct pvcalls_data_intf *intf = map->active.ring; | |
163 | RING_IDX cons, prod; | |
164 | int32_t error; | |
165 | ||
166 | cons = intf->in_cons; | |
167 | prod = intf->in_prod; | |
168 | error = intf->in_error; | |
169 | return (error != 0 || | |
170 | pvcalls_queued(prod, cons, | |
171 | XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER)) != 0); | |
172 | } | |
173 | ||
aa7ba376 SS |
174 | static irqreturn_t pvcalls_front_event_handler(int irq, void *dev_id) |
175 | { | |
2195046b SS |
176 | struct xenbus_device *dev = dev_id; |
177 | struct pvcalls_bedata *bedata; | |
178 | struct xen_pvcalls_response *rsp; | |
179 | uint8_t *src, *dst; | |
180 | int req_id = 0, more = 0, done = 0; | |
181 | ||
182 | if (dev == NULL) | |
183 | return IRQ_HANDLED; | |
184 | ||
185 | pvcalls_enter(); | |
186 | bedata = dev_get_drvdata(&dev->dev); | |
187 | if (bedata == NULL) { | |
188 | pvcalls_exit(); | |
189 | return IRQ_HANDLED; | |
190 | } | |
191 | ||
192 | again: | |
193 | while (RING_HAS_UNCONSUMED_RESPONSES(&bedata->ring)) { | |
194 | rsp = RING_GET_RESPONSE(&bedata->ring, bedata->ring.rsp_cons); | |
195 | ||
196 | req_id = rsp->req_id; | |
5842c835 SS |
197 | if (rsp->cmd == PVCALLS_POLL) { |
198 | struct sock_mapping *map = (struct sock_mapping *)(uintptr_t) | |
199 | rsp->u.poll.id; | |
200 | ||
201 | clear_bit(PVCALLS_FLAG_POLL_INFLIGHT, | |
202 | (void *)&map->passive.flags); | |
203 | /* | |
204 | * clear INFLIGHT, then set RET. It pairs with | |
205 | * the checks at the beginning of | |
206 | * pvcalls_front_poll_passive. | |
207 | */ | |
208 | smp_wmb(); | |
209 | set_bit(PVCALLS_FLAG_POLL_RET, | |
210 | (void *)&map->passive.flags); | |
211 | } else { | |
212 | dst = (uint8_t *)&bedata->rsp[req_id] + | |
213 | sizeof(rsp->req_id); | |
214 | src = (uint8_t *)rsp + sizeof(rsp->req_id); | |
215 | memcpy(dst, src, sizeof(*rsp) - sizeof(rsp->req_id)); | |
216 | /* | |
217 | * First copy the rest of the data, then req_id. It is | |
218 | * paired with the barrier when accessing bedata->rsp. | |
219 | */ | |
220 | smp_wmb(); | |
221 | bedata->rsp[req_id].req_id = req_id; | |
222 | } | |
2195046b SS |
223 | |
224 | done = 1; | |
225 | bedata->ring.rsp_cons++; | |
226 | } | |
227 | ||
228 | RING_FINAL_CHECK_FOR_RESPONSES(&bedata->ring, more); | |
229 | if (more) | |
230 | goto again; | |
231 | if (done) | |
232 | wake_up(&bedata->inflight_req); | |
233 | pvcalls_exit(); | |
aa7ba376 SS |
234 | return IRQ_HANDLED; |
235 | } | |
236 | ||
237 | static void pvcalls_front_free_map(struct pvcalls_bedata *bedata, | |
238 | struct sock_mapping *map) | |
239 | { | |
235a71c5 SS |
240 | int i; |
241 | ||
242 | unbind_from_irqhandler(map->active.irq, map); | |
243 | ||
244 | spin_lock(&bedata->socket_lock); | |
245 | if (!list_empty(&map->list)) | |
246 | list_del_init(&map->list); | |
247 | spin_unlock(&bedata->socket_lock); | |
248 | ||
249 | for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++) | |
250 | gnttab_end_foreign_access(map->active.ring->ref[i], 0, 0); | |
251 | gnttab_end_foreign_access(map->active.ref, 0, 0); | |
252 | free_page((unsigned long)map->active.ring); | |
253 | ||
254 | kfree(map); | |
aa7ba376 SS |
255 | } |
256 | ||
cb1c7d9b SS |
257 | static irqreturn_t pvcalls_front_conn_handler(int irq, void *sock_map) |
258 | { | |
259 | struct sock_mapping *map = sock_map; | |
260 | ||
261 | if (map == NULL) | |
262 | return IRQ_HANDLED; | |
263 | ||
264 | wake_up_interruptible(&map->active.inflight_conn_req); | |
265 | ||
266 | return IRQ_HANDLED; | |
267 | } | |
268 | ||
2195046b SS |
269 | int pvcalls_front_socket(struct socket *sock) |
270 | { | |
271 | struct pvcalls_bedata *bedata; | |
272 | struct sock_mapping *map = NULL; | |
273 | struct xen_pvcalls_request *req; | |
274 | int notify, req_id, ret; | |
275 | ||
276 | /* | |
277 | * PVCalls only supports domain AF_INET, | |
278 | * type SOCK_STREAM and protocol 0 sockets for now. | |
279 | * | |
280 | * Check socket type here, AF_INET and protocol checks are done | |
281 | * by the caller. | |
282 | */ | |
283 | if (sock->type != SOCK_STREAM) | |
284 | return -EOPNOTSUPP; | |
285 | ||
286 | pvcalls_enter(); | |
287 | if (!pvcalls_front_dev) { | |
288 | pvcalls_exit(); | |
289 | return -EACCES; | |
290 | } | |
291 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); | |
292 | ||
293 | map = kzalloc(sizeof(*map), GFP_KERNEL); | |
294 | if (map == NULL) { | |
295 | pvcalls_exit(); | |
296 | return -ENOMEM; | |
297 | } | |
298 | ||
299 | spin_lock(&bedata->socket_lock); | |
300 | ||
301 | ret = get_request(bedata, &req_id); | |
302 | if (ret < 0) { | |
303 | kfree(map); | |
304 | spin_unlock(&bedata->socket_lock); | |
305 | pvcalls_exit(); | |
306 | return ret; | |
307 | } | |
308 | ||
309 | /* | |
310 | * sock->sk->sk_send_head is not used for ip sockets: reuse the | |
311 | * field to store a pointer to the struct sock_mapping | |
312 | * corresponding to the socket. This way, we can easily get the | |
313 | * struct sock_mapping from the struct socket. | |
314 | */ | |
315 | sock->sk->sk_send_head = (void *)map; | |
316 | list_add_tail(&map->list, &bedata->socket_mappings); | |
317 | ||
318 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
319 | req->req_id = req_id; | |
320 | req->cmd = PVCALLS_SOCKET; | |
321 | req->u.socket.id = (uintptr_t) map; | |
322 | req->u.socket.domain = AF_INET; | |
323 | req->u.socket.type = SOCK_STREAM; | |
324 | req->u.socket.protocol = IPPROTO_IP; | |
325 | ||
326 | bedata->ring.req_prod_pvt++; | |
327 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
328 | spin_unlock(&bedata->socket_lock); | |
329 | if (notify) | |
330 | notify_remote_via_irq(bedata->irq); | |
331 | ||
332 | wait_event(bedata->inflight_req, | |
333 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
334 | ||
335 | /* read req_id, then the content */ | |
336 | smp_rmb(); | |
337 | ret = bedata->rsp[req_id].ret; | |
338 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
339 | ||
340 | pvcalls_exit(); | |
341 | return ret; | |
342 | } | |
343 | ||
9f51c05d WY |
344 | static void free_active_ring(struct sock_mapping *map) |
345 | { | |
b4711098 WY |
346 | if (!map->active.ring) |
347 | return; | |
348 | ||
9f51c05d WY |
349 | free_pages((unsigned long)map->active.data.in, |
350 | map->active.ring->ring_order); | |
351 | free_page((unsigned long)map->active.ring); | |
352 | } | |
353 | ||
354 | static int alloc_active_ring(struct sock_mapping *map) | |
355 | { | |
356 | void *bytes; | |
357 | ||
358 | map->active.ring = (struct pvcalls_data_intf *) | |
359 | get_zeroed_page(GFP_KERNEL); | |
360 | if (!map->active.ring) | |
361 | goto out; | |
362 | ||
363 | map->active.ring->ring_order = PVCALLS_RING_ORDER; | |
364 | bytes = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, | |
365 | PVCALLS_RING_ORDER); | |
366 | if (!bytes) | |
367 | goto out; | |
368 | ||
369 | map->active.data.in = bytes; | |
370 | map->active.data.out = bytes + | |
371 | XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
372 | ||
373 | return 0; | |
374 | ||
375 | out: | |
376 | free_active_ring(map); | |
377 | return -ENOMEM; | |
378 | } | |
379 | ||
cb1c7d9b SS |
380 | static int create_active(struct sock_mapping *map, int *evtchn) |
381 | { | |
382 | void *bytes; | |
383 | int ret = -ENOMEM, irq = -1, i; | |
384 | ||
385 | *evtchn = -1; | |
386 | init_waitqueue_head(&map->active.inflight_conn_req); | |
387 | ||
9f51c05d | 388 | bytes = map->active.data.in; |
cb1c7d9b SS |
389 | for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++) |
390 | map->active.ring->ref[i] = gnttab_grant_foreign_access( | |
391 | pvcalls_front_dev->otherend_id, | |
392 | pfn_to_gfn(virt_to_pfn(bytes) + i), 0); | |
393 | ||
394 | map->active.ref = gnttab_grant_foreign_access( | |
395 | pvcalls_front_dev->otherend_id, | |
396 | pfn_to_gfn(virt_to_pfn((void *)map->active.ring)), 0); | |
397 | ||
cb1c7d9b SS |
398 | ret = xenbus_alloc_evtchn(pvcalls_front_dev, evtchn); |
399 | if (ret) | |
400 | goto out_error; | |
401 | irq = bind_evtchn_to_irqhandler(*evtchn, pvcalls_front_conn_handler, | |
402 | 0, "pvcalls-frontend", map); | |
403 | if (irq < 0) { | |
404 | ret = irq; | |
405 | goto out_error; | |
406 | } | |
407 | ||
408 | map->active.irq = irq; | |
409 | map->active_socket = true; | |
410 | mutex_init(&map->active.in_mutex); | |
411 | mutex_init(&map->active.out_mutex); | |
412 | ||
413 | return 0; | |
414 | ||
415 | out_error: | |
773aaadc | 416 | if (*evtchn >= 0) |
cb1c7d9b | 417 | xenbus_free_evtchn(pvcalls_front_dev, *evtchn); |
cb1c7d9b SS |
418 | return ret; |
419 | } | |
420 | ||
421 | int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr, | |
422 | int addr_len, int flags) | |
423 | { | |
424 | struct pvcalls_bedata *bedata; | |
425 | struct sock_mapping *map = NULL; | |
426 | struct xen_pvcalls_request *req; | |
427 | int notify, req_id, ret, evtchn; | |
428 | ||
429 | if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM) | |
430 | return -EOPNOTSUPP; | |
431 | ||
64d68718 SS |
432 | map = pvcalls_enter_sock(sock); |
433 | if (IS_ERR(map)) | |
434 | return PTR_ERR(map); | |
cb1c7d9b SS |
435 | |
436 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); | |
9f51c05d WY |
437 | ret = alloc_active_ring(map); |
438 | if (ret < 0) { | |
439 | pvcalls_exit_sock(sock); | |
440 | return ret; | |
441 | } | |
cb1c7d9b | 442 | |
cb1c7d9b SS |
443 | spin_lock(&bedata->socket_lock); |
444 | ret = get_request(bedata, &req_id); | |
445 | if (ret < 0) { | |
446 | spin_unlock(&bedata->socket_lock); | |
9f51c05d | 447 | free_active_ring(map); |
64d68718 | 448 | pvcalls_exit_sock(sock); |
cb1c7d9b SS |
449 | return ret; |
450 | } | |
451 | ret = create_active(map, &evtchn); | |
452 | if (ret < 0) { | |
453 | spin_unlock(&bedata->socket_lock); | |
9f51c05d | 454 | free_active_ring(map); |
64d68718 | 455 | pvcalls_exit_sock(sock); |
cb1c7d9b SS |
456 | return ret; |
457 | } | |
458 | ||
459 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
460 | req->req_id = req_id; | |
461 | req->cmd = PVCALLS_CONNECT; | |
462 | req->u.connect.id = (uintptr_t)map; | |
463 | req->u.connect.len = addr_len; | |
464 | req->u.connect.flags = flags; | |
465 | req->u.connect.ref = map->active.ref; | |
466 | req->u.connect.evtchn = evtchn; | |
467 | memcpy(req->u.connect.addr, addr, sizeof(*addr)); | |
468 | ||
469 | map->sock = sock; | |
470 | ||
471 | bedata->ring.req_prod_pvt++; | |
472 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
473 | spin_unlock(&bedata->socket_lock); | |
474 | ||
475 | if (notify) | |
476 | notify_remote_via_irq(bedata->irq); | |
477 | ||
478 | wait_event(bedata->inflight_req, | |
479 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
480 | ||
481 | /* read req_id, then the content */ | |
482 | smp_rmb(); | |
483 | ret = bedata->rsp[req_id].ret; | |
484 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
64d68718 | 485 | pvcalls_exit_sock(sock); |
cb1c7d9b SS |
486 | return ret; |
487 | } | |
488 | ||
45ddce21 SS |
489 | static int __write_ring(struct pvcalls_data_intf *intf, |
490 | struct pvcalls_data *data, | |
491 | struct iov_iter *msg_iter, | |
492 | int len) | |
493 | { | |
494 | RING_IDX cons, prod, size, masked_prod, masked_cons; | |
495 | RING_IDX array_size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
496 | int32_t error; | |
497 | ||
498 | error = intf->out_error; | |
499 | if (error < 0) | |
500 | return error; | |
501 | cons = intf->out_cons; | |
502 | prod = intf->out_prod; | |
503 | /* read indexes before continuing */ | |
504 | virt_mb(); | |
505 | ||
506 | size = pvcalls_queued(prod, cons, array_size); | |
d90a1ca6 | 507 | if (size > array_size) |
45ddce21 | 508 | return -EINVAL; |
d90a1ca6 SS |
509 | if (size == array_size) |
510 | return 0; | |
45ddce21 SS |
511 | if (len > array_size - size) |
512 | len = array_size - size; | |
513 | ||
514 | masked_prod = pvcalls_mask(prod, array_size); | |
515 | masked_cons = pvcalls_mask(cons, array_size); | |
516 | ||
517 | if (masked_prod < masked_cons) { | |
518 | len = copy_from_iter(data->out + masked_prod, len, msg_iter); | |
519 | } else { | |
520 | if (len > array_size - masked_prod) { | |
521 | int ret = copy_from_iter(data->out + masked_prod, | |
522 | array_size - masked_prod, msg_iter); | |
523 | if (ret != array_size - masked_prod) { | |
524 | len = ret; | |
525 | goto out; | |
526 | } | |
527 | len = ret + copy_from_iter(data->out, len - ret, msg_iter); | |
528 | } else { | |
529 | len = copy_from_iter(data->out + masked_prod, len, msg_iter); | |
530 | } | |
531 | } | |
532 | out: | |
533 | /* write to ring before updating pointer */ | |
534 | virt_wmb(); | |
535 | intf->out_prod += len; | |
536 | ||
537 | return len; | |
538 | } | |
539 | ||
540 | int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg, | |
541 | size_t len) | |
542 | { | |
543 | struct pvcalls_bedata *bedata; | |
544 | struct sock_mapping *map; | |
545 | int sent, tot_sent = 0; | |
546 | int count = 0, flags; | |
547 | ||
548 | flags = msg->msg_flags; | |
549 | if (flags & (MSG_CONFIRM|MSG_DONTROUTE|MSG_EOR|MSG_OOB)) | |
550 | return -EOPNOTSUPP; | |
551 | ||
64d68718 SS |
552 | map = pvcalls_enter_sock(sock); |
553 | if (IS_ERR(map)) | |
554 | return PTR_ERR(map); | |
45ddce21 SS |
555 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
556 | ||
45ddce21 SS |
557 | mutex_lock(&map->active.out_mutex); |
558 | if ((flags & MSG_DONTWAIT) && !pvcalls_front_write_todo(map)) { | |
559 | mutex_unlock(&map->active.out_mutex); | |
64d68718 | 560 | pvcalls_exit_sock(sock); |
45ddce21 SS |
561 | return -EAGAIN; |
562 | } | |
563 | if (len > INT_MAX) | |
564 | len = INT_MAX; | |
565 | ||
566 | again: | |
567 | count++; | |
568 | sent = __write_ring(map->active.ring, | |
569 | &map->active.data, &msg->msg_iter, | |
570 | len); | |
571 | if (sent > 0) { | |
572 | len -= sent; | |
573 | tot_sent += sent; | |
574 | notify_remote_via_irq(map->active.irq); | |
575 | } | |
576 | if (sent >= 0 && len > 0 && count < PVCALLS_FRONT_MAX_SPIN) | |
577 | goto again; | |
578 | if (sent < 0) | |
579 | tot_sent = sent; | |
580 | ||
581 | mutex_unlock(&map->active.out_mutex); | |
64d68718 | 582 | pvcalls_exit_sock(sock); |
45ddce21 SS |
583 | return tot_sent; |
584 | } | |
585 | ||
ae0d0405 SS |
586 | static int __read_ring(struct pvcalls_data_intf *intf, |
587 | struct pvcalls_data *data, | |
588 | struct iov_iter *msg_iter, | |
589 | size_t len, int flags) | |
590 | { | |
591 | RING_IDX cons, prod, size, masked_prod, masked_cons; | |
592 | RING_IDX array_size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
593 | int32_t error; | |
594 | ||
595 | cons = intf->in_cons; | |
596 | prod = intf->in_prod; | |
597 | error = intf->in_error; | |
598 | /* get pointers before reading from the ring */ | |
599 | virt_rmb(); | |
ae0d0405 SS |
600 | |
601 | size = pvcalls_queued(prod, cons, array_size); | |
602 | masked_prod = pvcalls_mask(prod, array_size); | |
603 | masked_cons = pvcalls_mask(cons, array_size); | |
604 | ||
605 | if (size == 0) | |
b79470b6 | 606 | return error ?: size; |
ae0d0405 SS |
607 | |
608 | if (len > size) | |
609 | len = size; | |
610 | ||
611 | if (masked_prod > masked_cons) { | |
612 | len = copy_to_iter(data->in + masked_cons, len, msg_iter); | |
613 | } else { | |
614 | if (len > (array_size - masked_cons)) { | |
615 | int ret = copy_to_iter(data->in + masked_cons, | |
616 | array_size - masked_cons, msg_iter); | |
617 | if (ret != array_size - masked_cons) { | |
618 | len = ret; | |
619 | goto out; | |
620 | } | |
621 | len = ret + copy_to_iter(data->in, len - ret, msg_iter); | |
622 | } else { | |
623 | len = copy_to_iter(data->in + masked_cons, len, msg_iter); | |
624 | } | |
625 | } | |
626 | out: | |
627 | /* read data from the ring before increasing the index */ | |
628 | virt_mb(); | |
629 | if (!(flags & MSG_PEEK)) | |
630 | intf->in_cons += len; | |
631 | ||
632 | return len; | |
633 | } | |
634 | ||
635 | int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, | |
636 | int flags) | |
637 | { | |
638 | struct pvcalls_bedata *bedata; | |
639 | int ret; | |
640 | struct sock_mapping *map; | |
641 | ||
642 | if (flags & (MSG_CMSG_CLOEXEC|MSG_ERRQUEUE|MSG_OOB|MSG_TRUNC)) | |
643 | return -EOPNOTSUPP; | |
644 | ||
64d68718 SS |
645 | map = pvcalls_enter_sock(sock); |
646 | if (IS_ERR(map)) | |
647 | return PTR_ERR(map); | |
ae0d0405 SS |
648 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
649 | ||
ae0d0405 SS |
650 | mutex_lock(&map->active.in_mutex); |
651 | if (len > XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER)) | |
652 | len = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
653 | ||
654 | while (!(flags & MSG_DONTWAIT) && !pvcalls_front_read_todo(map)) { | |
655 | wait_event_interruptible(map->active.inflight_conn_req, | |
656 | pvcalls_front_read_todo(map)); | |
657 | } | |
658 | ret = __read_ring(map->active.ring, &map->active.data, | |
659 | &msg->msg_iter, len, flags); | |
660 | ||
661 | if (ret > 0) | |
662 | notify_remote_via_irq(map->active.irq); | |
663 | if (ret == 0) | |
664 | ret = (flags & MSG_DONTWAIT) ? -EAGAIN : 0; | |
665 | if (ret == -ENOTCONN) | |
666 | ret = 0; | |
667 | ||
668 | mutex_unlock(&map->active.in_mutex); | |
64d68718 | 669 | pvcalls_exit_sock(sock); |
ae0d0405 SS |
670 | return ret; |
671 | } | |
672 | ||
67ea9893 SS |
673 | int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len) |
674 | { | |
675 | struct pvcalls_bedata *bedata; | |
676 | struct sock_mapping *map = NULL; | |
677 | struct xen_pvcalls_request *req; | |
678 | int notify, req_id, ret; | |
679 | ||
680 | if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM) | |
681 | return -EOPNOTSUPP; | |
682 | ||
64d68718 SS |
683 | map = pvcalls_enter_sock(sock); |
684 | if (IS_ERR(map)) | |
685 | return PTR_ERR(map); | |
67ea9893 SS |
686 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
687 | ||
67ea9893 SS |
688 | spin_lock(&bedata->socket_lock); |
689 | ret = get_request(bedata, &req_id); | |
690 | if (ret < 0) { | |
691 | spin_unlock(&bedata->socket_lock); | |
64d68718 | 692 | pvcalls_exit_sock(sock); |
67ea9893 SS |
693 | return ret; |
694 | } | |
695 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
696 | req->req_id = req_id; | |
697 | map->sock = sock; | |
698 | req->cmd = PVCALLS_BIND; | |
699 | req->u.bind.id = (uintptr_t)map; | |
700 | memcpy(req->u.bind.addr, addr, sizeof(*addr)); | |
701 | req->u.bind.len = addr_len; | |
702 | ||
9774c6cc SS |
703 | init_waitqueue_head(&map->passive.inflight_accept_req); |
704 | ||
67ea9893 SS |
705 | map->active_socket = false; |
706 | ||
707 | bedata->ring.req_prod_pvt++; | |
708 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
709 | spin_unlock(&bedata->socket_lock); | |
710 | if (notify) | |
711 | notify_remote_via_irq(bedata->irq); | |
712 | ||
713 | wait_event(bedata->inflight_req, | |
714 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
715 | ||
716 | /* read req_id, then the content */ | |
717 | smp_rmb(); | |
718 | ret = bedata->rsp[req_id].ret; | |
719 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
720 | ||
721 | map->passive.status = PVCALLS_STATUS_BIND; | |
64d68718 | 722 | pvcalls_exit_sock(sock); |
67ea9893 SS |
723 | return 0; |
724 | } | |
725 | ||
1853f11d SS |
726 | int pvcalls_front_listen(struct socket *sock, int backlog) |
727 | { | |
728 | struct pvcalls_bedata *bedata; | |
729 | struct sock_mapping *map; | |
730 | struct xen_pvcalls_request *req; | |
731 | int notify, req_id, ret; | |
732 | ||
64d68718 SS |
733 | map = pvcalls_enter_sock(sock); |
734 | if (IS_ERR(map)) | |
735 | return PTR_ERR(map); | |
1853f11d SS |
736 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
737 | ||
1853f11d | 738 | if (map->passive.status != PVCALLS_STATUS_BIND) { |
64d68718 | 739 | pvcalls_exit_sock(sock); |
1853f11d SS |
740 | return -EOPNOTSUPP; |
741 | } | |
742 | ||
743 | spin_lock(&bedata->socket_lock); | |
744 | ret = get_request(bedata, &req_id); | |
745 | if (ret < 0) { | |
746 | spin_unlock(&bedata->socket_lock); | |
64d68718 | 747 | pvcalls_exit_sock(sock); |
1853f11d SS |
748 | return ret; |
749 | } | |
750 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
751 | req->req_id = req_id; | |
752 | req->cmd = PVCALLS_LISTEN; | |
753 | req->u.listen.id = (uintptr_t) map; | |
754 | req->u.listen.backlog = backlog; | |
755 | ||
756 | bedata->ring.req_prod_pvt++; | |
757 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
758 | spin_unlock(&bedata->socket_lock); | |
759 | if (notify) | |
760 | notify_remote_via_irq(bedata->irq); | |
761 | ||
762 | wait_event(bedata->inflight_req, | |
763 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
764 | ||
765 | /* read req_id, then the content */ | |
766 | smp_rmb(); | |
767 | ret = bedata->rsp[req_id].ret; | |
768 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
769 | ||
770 | map->passive.status = PVCALLS_STATUS_LISTEN; | |
64d68718 | 771 | pvcalls_exit_sock(sock); |
1853f11d SS |
772 | return ret; |
773 | } | |
774 | ||
9774c6cc SS |
775 | int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags) |
776 | { | |
777 | struct pvcalls_bedata *bedata; | |
778 | struct sock_mapping *map; | |
779 | struct sock_mapping *map2 = NULL; | |
780 | struct xen_pvcalls_request *req; | |
781 | int notify, req_id, ret, evtchn, nonblock; | |
782 | ||
64d68718 SS |
783 | map = pvcalls_enter_sock(sock); |
784 | if (IS_ERR(map)) | |
785 | return PTR_ERR(map); | |
9774c6cc SS |
786 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
787 | ||
9774c6cc | 788 | if (map->passive.status != PVCALLS_STATUS_LISTEN) { |
64d68718 | 789 | pvcalls_exit_sock(sock); |
9774c6cc SS |
790 | return -EINVAL; |
791 | } | |
792 | ||
793 | nonblock = flags & SOCK_NONBLOCK; | |
794 | /* | |
795 | * Backend only supports 1 inflight accept request, will return | |
796 | * errors for the others | |
797 | */ | |
798 | if (test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
799 | (void *)&map->passive.flags)) { | |
800 | req_id = READ_ONCE(map->passive.inflight_req_id); | |
801 | if (req_id != PVCALLS_INVALID_ID && | |
802 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id) { | |
803 | map2 = map->passive.accept_map; | |
804 | goto received; | |
805 | } | |
806 | if (nonblock) { | |
64d68718 | 807 | pvcalls_exit_sock(sock); |
9774c6cc SS |
808 | return -EAGAIN; |
809 | } | |
810 | if (wait_event_interruptible(map->passive.inflight_accept_req, | |
811 | !test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
812 | (void *)&map->passive.flags))) { | |
64d68718 | 813 | pvcalls_exit_sock(sock); |
9774c6cc SS |
814 | return -EINTR; |
815 | } | |
816 | } | |
817 | ||
9f51c05d WY |
818 | map2 = kzalloc(sizeof(*map2), GFP_KERNEL); |
819 | if (map2 == NULL) { | |
9774c6cc SS |
820 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, |
821 | (void *)&map->passive.flags); | |
9f51c05d WY |
822 | pvcalls_exit_sock(sock); |
823 | return -ENOMEM; | |
824 | } | |
825 | ret = alloc_active_ring(map2); | |
826 | if (ret < 0) { | |
827 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
828 | (void *)&map->passive.flags); | |
829 | kfree(map2); | |
64d68718 | 830 | pvcalls_exit_sock(sock); |
9774c6cc SS |
831 | return ret; |
832 | } | |
9f51c05d WY |
833 | spin_lock(&bedata->socket_lock); |
834 | ret = get_request(bedata, &req_id); | |
835 | if (ret < 0) { | |
9774c6cc SS |
836 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, |
837 | (void *)&map->passive.flags); | |
838 | spin_unlock(&bedata->socket_lock); | |
9f51c05d WY |
839 | free_active_ring(map2); |
840 | kfree(map2); | |
64d68718 | 841 | pvcalls_exit_sock(sock); |
9f51c05d | 842 | return ret; |
9774c6cc | 843 | } |
9f51c05d | 844 | |
9774c6cc SS |
845 | ret = create_active(map2, &evtchn); |
846 | if (ret < 0) { | |
9f51c05d | 847 | free_active_ring(map2); |
9774c6cc SS |
848 | kfree(map2); |
849 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
850 | (void *)&map->passive.flags); | |
851 | spin_unlock(&bedata->socket_lock); | |
64d68718 | 852 | pvcalls_exit_sock(sock); |
9774c6cc SS |
853 | return ret; |
854 | } | |
855 | list_add_tail(&map2->list, &bedata->socket_mappings); | |
856 | ||
857 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
858 | req->req_id = req_id; | |
859 | req->cmd = PVCALLS_ACCEPT; | |
860 | req->u.accept.id = (uintptr_t) map; | |
861 | req->u.accept.ref = map2->active.ref; | |
862 | req->u.accept.id_new = (uintptr_t) map2; | |
863 | req->u.accept.evtchn = evtchn; | |
864 | map->passive.accept_map = map2; | |
865 | ||
866 | bedata->ring.req_prod_pvt++; | |
867 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
868 | spin_unlock(&bedata->socket_lock); | |
869 | if (notify) | |
870 | notify_remote_via_irq(bedata->irq); | |
871 | /* We could check if we have received a response before returning. */ | |
872 | if (nonblock) { | |
873 | WRITE_ONCE(map->passive.inflight_req_id, req_id); | |
64d68718 | 874 | pvcalls_exit_sock(sock); |
9774c6cc SS |
875 | return -EAGAIN; |
876 | } | |
877 | ||
878 | if (wait_event_interruptible(bedata->inflight_req, | |
879 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id)) { | |
64d68718 | 880 | pvcalls_exit_sock(sock); |
9774c6cc SS |
881 | return -EINTR; |
882 | } | |
883 | /* read req_id, then the content */ | |
884 | smp_rmb(); | |
885 | ||
886 | received: | |
887 | map2->sock = newsock; | |
beee1fbe | 888 | newsock->sk = sk_alloc(sock_net(sock->sk), PF_INET, GFP_KERNEL, &pvcalls_proto, false); |
9774c6cc SS |
889 | if (!newsock->sk) { |
890 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
891 | map->passive.inflight_req_id = PVCALLS_INVALID_ID; | |
892 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
893 | (void *)&map->passive.flags); | |
894 | pvcalls_front_free_map(bedata, map2); | |
64d68718 | 895 | pvcalls_exit_sock(sock); |
9774c6cc SS |
896 | return -ENOMEM; |
897 | } | |
898 | newsock->sk->sk_send_head = (void *)map2; | |
899 | ||
900 | ret = bedata->rsp[req_id].ret; | |
901 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
902 | map->passive.inflight_req_id = PVCALLS_INVALID_ID; | |
903 | ||
904 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, (void *)&map->passive.flags); | |
905 | wake_up(&map->passive.inflight_accept_req); | |
906 | ||
64d68718 | 907 | pvcalls_exit_sock(sock); |
9774c6cc SS |
908 | return ret; |
909 | } | |
910 | ||
afc9a42b | 911 | static __poll_t pvcalls_front_poll_passive(struct file *file, |
5842c835 SS |
912 | struct pvcalls_bedata *bedata, |
913 | struct sock_mapping *map, | |
914 | poll_table *wait) | |
915 | { | |
916 | int notify, req_id, ret; | |
917 | struct xen_pvcalls_request *req; | |
918 | ||
919 | if (test_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
920 | (void *)&map->passive.flags)) { | |
921 | uint32_t req_id = READ_ONCE(map->passive.inflight_req_id); | |
922 | ||
923 | if (req_id != PVCALLS_INVALID_ID && | |
924 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id) | |
a9a08845 | 925 | return EPOLLIN | EPOLLRDNORM; |
5842c835 SS |
926 | |
927 | poll_wait(file, &map->passive.inflight_accept_req, wait); | |
928 | return 0; | |
929 | } | |
930 | ||
931 | if (test_and_clear_bit(PVCALLS_FLAG_POLL_RET, | |
932 | (void *)&map->passive.flags)) | |
a9a08845 | 933 | return EPOLLIN | EPOLLRDNORM; |
5842c835 SS |
934 | |
935 | /* | |
936 | * First check RET, then INFLIGHT. No barriers necessary to | |
937 | * ensure execution ordering because of the conditional | |
938 | * instructions creating control dependencies. | |
939 | */ | |
940 | ||
941 | if (test_and_set_bit(PVCALLS_FLAG_POLL_INFLIGHT, | |
942 | (void *)&map->passive.flags)) { | |
943 | poll_wait(file, &bedata->inflight_req, wait); | |
944 | return 0; | |
945 | } | |
946 | ||
947 | spin_lock(&bedata->socket_lock); | |
948 | ret = get_request(bedata, &req_id); | |
949 | if (ret < 0) { | |
950 | spin_unlock(&bedata->socket_lock); | |
951 | return ret; | |
952 | } | |
953 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
954 | req->req_id = req_id; | |
955 | req->cmd = PVCALLS_POLL; | |
956 | req->u.poll.id = (uintptr_t) map; | |
957 | ||
958 | bedata->ring.req_prod_pvt++; | |
959 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
960 | spin_unlock(&bedata->socket_lock); | |
961 | if (notify) | |
962 | notify_remote_via_irq(bedata->irq); | |
963 | ||
964 | poll_wait(file, &bedata->inflight_req, wait); | |
965 | return 0; | |
966 | } | |
967 | ||
afc9a42b | 968 | static __poll_t pvcalls_front_poll_active(struct file *file, |
5842c835 SS |
969 | struct pvcalls_bedata *bedata, |
970 | struct sock_mapping *map, | |
971 | poll_table *wait) | |
972 | { | |
afc9a42b | 973 | __poll_t mask = 0; |
5842c835 SS |
974 | int32_t in_error, out_error; |
975 | struct pvcalls_data_intf *intf = map->active.ring; | |
976 | ||
977 | out_error = intf->out_error; | |
978 | in_error = intf->in_error; | |
979 | ||
980 | poll_wait(file, &map->active.inflight_conn_req, wait); | |
981 | if (pvcalls_front_write_todo(map)) | |
a9a08845 | 982 | mask |= EPOLLOUT | EPOLLWRNORM; |
5842c835 | 983 | if (pvcalls_front_read_todo(map)) |
a9a08845 | 984 | mask |= EPOLLIN | EPOLLRDNORM; |
5842c835 | 985 | if (in_error != 0 || out_error != 0) |
a9a08845 | 986 | mask |= EPOLLERR; |
5842c835 SS |
987 | |
988 | return mask; | |
989 | } | |
990 | ||
afc9a42b | 991 | __poll_t pvcalls_front_poll(struct file *file, struct socket *sock, |
5842c835 SS |
992 | poll_table *wait) |
993 | { | |
994 | struct pvcalls_bedata *bedata; | |
995 | struct sock_mapping *map; | |
afc9a42b | 996 | __poll_t ret; |
5842c835 | 997 | |
64d68718 SS |
998 | map = pvcalls_enter_sock(sock); |
999 | if (IS_ERR(map)) | |
a9a08845 | 1000 | return EPOLLNVAL; |
5842c835 SS |
1001 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
1002 | ||
5842c835 SS |
1003 | if (map->active_socket) |
1004 | ret = pvcalls_front_poll_active(file, bedata, map, wait); | |
1005 | else | |
1006 | ret = pvcalls_front_poll_passive(file, bedata, map, wait); | |
64d68718 | 1007 | pvcalls_exit_sock(sock); |
5842c835 SS |
1008 | return ret; |
1009 | } | |
1010 | ||
235a71c5 SS |
1011 | int pvcalls_front_release(struct socket *sock) |
1012 | { | |
1013 | struct pvcalls_bedata *bedata; | |
1014 | struct sock_mapping *map; | |
1015 | int req_id, notify, ret; | |
1016 | struct xen_pvcalls_request *req; | |
1017 | ||
1018 | if (sock->sk == NULL) | |
1019 | return 0; | |
1020 | ||
64d68718 SS |
1021 | map = pvcalls_enter_sock(sock); |
1022 | if (IS_ERR(map)) { | |
1023 | if (PTR_ERR(map) == -ENOTCONN) | |
1024 | return -EIO; | |
1025 | else | |
1026 | return 0; | |
235a71c5 | 1027 | } |
235a71c5 SS |
1028 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
1029 | ||
235a71c5 SS |
1030 | spin_lock(&bedata->socket_lock); |
1031 | ret = get_request(bedata, &req_id); | |
1032 | if (ret < 0) { | |
1033 | spin_unlock(&bedata->socket_lock); | |
64d68718 | 1034 | pvcalls_exit_sock(sock); |
235a71c5 SS |
1035 | return ret; |
1036 | } | |
1037 | sock->sk->sk_send_head = NULL; | |
1038 | ||
1039 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
1040 | req->req_id = req_id; | |
1041 | req->cmd = PVCALLS_RELEASE; | |
1042 | req->u.release.id = (uintptr_t)map; | |
1043 | ||
1044 | bedata->ring.req_prod_pvt++; | |
1045 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
1046 | spin_unlock(&bedata->socket_lock); | |
1047 | if (notify) | |
1048 | notify_remote_via_irq(bedata->irq); | |
1049 | ||
1050 | wait_event(bedata->inflight_req, | |
1051 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
1052 | ||
1053 | if (map->active_socket) { | |
1054 | /* | |
1055 | * Set in_error and wake up inflight_conn_req to force | |
1056 | * recvmsg waiters to exit. | |
1057 | */ | |
1058 | map->active.ring->in_error = -EBADF; | |
1059 | wake_up_interruptible(&map->active.inflight_conn_req); | |
1060 | ||
1061 | /* | |
646d944c SS |
1062 | * We need to make sure that sendmsg/recvmsg on this socket have |
1063 | * not started before we've cleared sk_send_head here. The | |
64d68718 SS |
1064 | * easiest way to guarantee this is to see that no pvcalls |
1065 | * (other than us) is in progress on this socket. | |
235a71c5 | 1066 | */ |
64d68718 | 1067 | while (atomic_read(&map->refcount) > 1) |
235a71c5 SS |
1068 | cpu_relax(); |
1069 | ||
1070 | pvcalls_front_free_map(bedata, map); | |
1071 | } else { | |
d1a75e08 SS |
1072 | wake_up(&bedata->inflight_req); |
1073 | wake_up(&map->passive.inflight_accept_req); | |
1074 | ||
1075 | while (atomic_read(&map->refcount) > 1) | |
1076 | cpu_relax(); | |
1077 | ||
235a71c5 SS |
1078 | spin_lock(&bedata->socket_lock); |
1079 | list_del(&map->list); | |
1080 | spin_unlock(&bedata->socket_lock); | |
96283f9a SS |
1081 | if (READ_ONCE(map->passive.inflight_req_id) != PVCALLS_INVALID_ID && |
1082 | READ_ONCE(map->passive.inflight_req_id) != 0) { | |
235a71c5 SS |
1083 | pvcalls_front_free_map(bedata, |
1084 | map->passive.accept_map); | |
1085 | } | |
1086 | kfree(map); | |
1087 | } | |
1088 | WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID); | |
1089 | ||
1090 | pvcalls_exit(); | |
1091 | return 0; | |
1092 | } | |
1093 | ||
416efba0 SS |
1094 | static const struct xenbus_device_id pvcalls_front_ids[] = { |
1095 | { "pvcalls" }, | |
1096 | { "" } | |
1097 | }; | |
1098 | ||
1099 | static int pvcalls_front_remove(struct xenbus_device *dev) | |
1100 | { | |
aa7ba376 SS |
1101 | struct pvcalls_bedata *bedata; |
1102 | struct sock_mapping *map = NULL, *n; | |
1103 | ||
1104 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); | |
1105 | dev_set_drvdata(&dev->dev, NULL); | |
1106 | pvcalls_front_dev = NULL; | |
1107 | if (bedata->irq >= 0) | |
1108 | unbind_from_irqhandler(bedata->irq, dev); | |
1109 | ||
cb1c7d9b SS |
1110 | list_for_each_entry_safe(map, n, &bedata->socket_mappings, list) { |
1111 | map->sock->sk->sk_send_head = NULL; | |
1112 | if (map->active_socket) { | |
1113 | map->active.ring->in_error = -EBADF; | |
1114 | wake_up_interruptible(&map->active.inflight_conn_req); | |
1115 | } | |
1116 | } | |
1117 | ||
aa7ba376 SS |
1118 | smp_mb(); |
1119 | while (atomic_read(&pvcalls_refcount) > 0) | |
1120 | cpu_relax(); | |
1121 | list_for_each_entry_safe(map, n, &bedata->socket_mappings, list) { | |
1122 | if (map->active_socket) { | |
1123 | /* No need to lock, refcount is 0 */ | |
1124 | pvcalls_front_free_map(bedata, map); | |
1125 | } else { | |
1126 | list_del(&map->list); | |
1127 | kfree(map); | |
1128 | } | |
1129 | } | |
1ab134ca | 1130 | if (bedata->ref != -1) |
aa7ba376 SS |
1131 | gnttab_end_foreign_access(bedata->ref, 0, 0); |
1132 | kfree(bedata->ring.sring); | |
1133 | kfree(bedata); | |
1134 | xenbus_switch_state(dev, XenbusStateClosed); | |
416efba0 SS |
1135 | return 0; |
1136 | } | |
1137 | ||
1138 | static int pvcalls_front_probe(struct xenbus_device *dev, | |
1139 | const struct xenbus_device_id *id) | |
1140 | { | |
21968190 SS |
1141 | int ret = -ENOMEM, evtchn, i; |
1142 | unsigned int max_page_order, function_calls, len; | |
1143 | char *versions; | |
1144 | grant_ref_t gref_head = 0; | |
1145 | struct xenbus_transaction xbt; | |
1146 | struct pvcalls_bedata *bedata = NULL; | |
1147 | struct xen_pvcalls_sring *sring; | |
1148 | ||
1149 | if (pvcalls_front_dev != NULL) { | |
1150 | dev_err(&dev->dev, "only one PV Calls connection supported\n"); | |
1151 | return -EINVAL; | |
1152 | } | |
1153 | ||
1154 | versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len); | |
8c71fa88 DC |
1155 | if (IS_ERR(versions)) |
1156 | return PTR_ERR(versions); | |
21968190 SS |
1157 | if (!len) |
1158 | return -EINVAL; | |
1159 | if (strcmp(versions, "1")) { | |
1160 | kfree(versions); | |
1161 | return -EINVAL; | |
1162 | } | |
1163 | kfree(versions); | |
1164 | max_page_order = xenbus_read_unsigned(dev->otherend, | |
1165 | "max-page-order", 0); | |
1166 | if (max_page_order < PVCALLS_RING_ORDER) | |
1167 | return -ENODEV; | |
1168 | function_calls = xenbus_read_unsigned(dev->otherend, | |
1169 | "function-calls", 0); | |
1170 | /* See XENBUS_FUNCTIONS_CALLS in pvcalls.h */ | |
1171 | if (function_calls != 1) | |
1172 | return -ENODEV; | |
1173 | pr_info("%s max-page-order is %u\n", __func__, max_page_order); | |
1174 | ||
1175 | bedata = kzalloc(sizeof(struct pvcalls_bedata), GFP_KERNEL); | |
1176 | if (!bedata) | |
1177 | return -ENOMEM; | |
1178 | ||
1179 | dev_set_drvdata(&dev->dev, bedata); | |
1180 | pvcalls_front_dev = dev; | |
1181 | init_waitqueue_head(&bedata->inflight_req); | |
1182 | INIT_LIST_HEAD(&bedata->socket_mappings); | |
1183 | spin_lock_init(&bedata->socket_lock); | |
1184 | bedata->irq = -1; | |
1185 | bedata->ref = -1; | |
1186 | ||
1187 | for (i = 0; i < PVCALLS_NR_RSP_PER_RING; i++) | |
1188 | bedata->rsp[i].req_id = PVCALLS_INVALID_ID; | |
1189 | ||
1190 | sring = (struct xen_pvcalls_sring *) __get_free_page(GFP_KERNEL | | |
1191 | __GFP_ZERO); | |
1192 | if (!sring) | |
1193 | goto error; | |
1194 | SHARED_RING_INIT(sring); | |
1195 | FRONT_RING_INIT(&bedata->ring, sring, XEN_PAGE_SIZE); | |
1196 | ||
1197 | ret = xenbus_alloc_evtchn(dev, &evtchn); | |
1198 | if (ret) | |
1199 | goto error; | |
1200 | ||
1201 | bedata->irq = bind_evtchn_to_irqhandler(evtchn, | |
1202 | pvcalls_front_event_handler, | |
1203 | 0, "pvcalls-frontend", dev); | |
1204 | if (bedata->irq < 0) { | |
1205 | ret = bedata->irq; | |
1206 | goto error; | |
1207 | } | |
1208 | ||
1209 | ret = gnttab_alloc_grant_references(1, &gref_head); | |
1210 | if (ret < 0) | |
1211 | goto error; | |
95110ac8 CIK |
1212 | ret = gnttab_claim_grant_reference(&gref_head); |
1213 | if (ret < 0) | |
21968190 | 1214 | goto error; |
95110ac8 | 1215 | bedata->ref = ret; |
21968190 SS |
1216 | gnttab_grant_foreign_access_ref(bedata->ref, dev->otherend_id, |
1217 | virt_to_gfn((void *)sring), 0); | |
1218 | ||
1219 | again: | |
1220 | ret = xenbus_transaction_start(&xbt); | |
1221 | if (ret) { | |
1222 | xenbus_dev_fatal(dev, ret, "starting transaction"); | |
1223 | goto error; | |
1224 | } | |
1225 | ret = xenbus_printf(xbt, dev->nodename, "version", "%u", 1); | |
1226 | if (ret) | |
1227 | goto error_xenbus; | |
1228 | ret = xenbus_printf(xbt, dev->nodename, "ring-ref", "%d", bedata->ref); | |
1229 | if (ret) | |
1230 | goto error_xenbus; | |
1231 | ret = xenbus_printf(xbt, dev->nodename, "port", "%u", | |
1232 | evtchn); | |
1233 | if (ret) | |
1234 | goto error_xenbus; | |
1235 | ret = xenbus_transaction_end(xbt, 0); | |
1236 | if (ret) { | |
1237 | if (ret == -EAGAIN) | |
1238 | goto again; | |
1239 | xenbus_dev_fatal(dev, ret, "completing transaction"); | |
1240 | goto error; | |
1241 | } | |
1242 | xenbus_switch_state(dev, XenbusStateInitialised); | |
1243 | ||
416efba0 | 1244 | return 0; |
21968190 SS |
1245 | |
1246 | error_xenbus: | |
1247 | xenbus_transaction_end(xbt, 1); | |
1248 | xenbus_dev_fatal(dev, ret, "writing xenstore"); | |
1249 | error: | |
1250 | pvcalls_front_remove(dev); | |
1251 | return ret; | |
416efba0 SS |
1252 | } |
1253 | ||
1254 | static void pvcalls_front_changed(struct xenbus_device *dev, | |
1255 | enum xenbus_state backend_state) | |
1256 | { | |
21968190 SS |
1257 | switch (backend_state) { |
1258 | case XenbusStateReconfiguring: | |
1259 | case XenbusStateReconfigured: | |
1260 | case XenbusStateInitialising: | |
1261 | case XenbusStateInitialised: | |
1262 | case XenbusStateUnknown: | |
1263 | break; | |
1264 | ||
1265 | case XenbusStateInitWait: | |
1266 | break; | |
1267 | ||
1268 | case XenbusStateConnected: | |
1269 | xenbus_switch_state(dev, XenbusStateConnected); | |
1270 | break; | |
1271 | ||
1272 | case XenbusStateClosed: | |
1273 | if (dev->state == XenbusStateClosed) | |
1274 | break; | |
3d8765d4 GS |
1275 | /* Missed the backend's CLOSING state */ |
1276 | /* fall through */ | |
21968190 SS |
1277 | case XenbusStateClosing: |
1278 | xenbus_frontend_closed(dev); | |
1279 | break; | |
1280 | } | |
416efba0 SS |
1281 | } |
1282 | ||
1283 | static struct xenbus_driver pvcalls_front_driver = { | |
1284 | .ids = pvcalls_front_ids, | |
1285 | .probe = pvcalls_front_probe, | |
1286 | .remove = pvcalls_front_remove, | |
1287 | .otherend_changed = pvcalls_front_changed, | |
1288 | }; | |
1289 | ||
1290 | static int __init pvcalls_frontend_init(void) | |
1291 | { | |
1292 | if (!xen_domain()) | |
1293 | return -ENODEV; | |
1294 | ||
1295 | pr_info("Initialising Xen pvcalls frontend driver\n"); | |
1296 | ||
1297 | return xenbus_register_frontend(&pvcalls_front_driver); | |
1298 | } | |
1299 | ||
1300 | module_init(pvcalls_frontend_init); | |
24e7f84d BO |
1301 | |
1302 | MODULE_DESCRIPTION("Xen PV Calls frontend driver"); | |
1303 | MODULE_AUTHOR("Stefano Stabellini <sstabellini@kernel.org>"); | |
1304 | MODULE_LICENSE("GPL"); |