Commit | Line | Data |
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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
416efba0 SS |
2 | /* |
3 | * (c) 2017 Stefano Stabellini <stefano@aporeto.com> | |
416efba0 SS |
4 | */ |
5 | ||
6 | #include <linux/module.h> | |
2195046b SS |
7 | #include <linux/net.h> |
8 | #include <linux/socket.h> | |
9 | ||
10 | #include <net/sock.h> | |
416efba0 SS |
11 | |
12 | #include <xen/events.h> | |
13 | #include <xen/grant_table.h> | |
14 | #include <xen/xen.h> | |
15 | #include <xen/xenbus.h> | |
16 | #include <xen/interface/io/pvcalls.h> | |
17 | ||
2195046b SS |
18 | #include "pvcalls-front.h" |
19 | ||
aa7ba376 SS |
20 | #define PVCALLS_INVALID_ID UINT_MAX |
21 | #define PVCALLS_RING_ORDER XENBUS_MAX_RING_GRANT_ORDER | |
22 | #define PVCALLS_NR_RSP_PER_RING __CONST_RING_SIZE(xen_pvcalls, XEN_PAGE_SIZE) | |
45ddce21 | 23 | #define PVCALLS_FRONT_MAX_SPIN 5000 |
aa7ba376 | 24 | |
beee1fbe SS |
25 | static struct proto pvcalls_proto = { |
26 | .name = "PVCalls", | |
27 | .owner = THIS_MODULE, | |
28 | .obj_size = sizeof(struct sock), | |
29 | }; | |
30 | ||
aa7ba376 SS |
31 | struct pvcalls_bedata { |
32 | struct xen_pvcalls_front_ring ring; | |
33 | grant_ref_t ref; | |
34 | int irq; | |
35 | ||
36 | struct list_head socket_mappings; | |
37 | spinlock_t socket_lock; | |
38 | ||
39 | wait_queue_head_t inflight_req; | |
40 | struct xen_pvcalls_response rsp[PVCALLS_NR_RSP_PER_RING]; | |
41 | }; | |
42 | /* Only one front/back connection supported. */ | |
43 | static struct xenbus_device *pvcalls_front_dev; | |
44 | static atomic_t pvcalls_refcount; | |
45 | ||
46 | /* first increment refcount, then proceed */ | |
47 | #define pvcalls_enter() { \ | |
48 | atomic_inc(&pvcalls_refcount); \ | |
49 | } | |
50 | ||
51 | /* first complete other operations, then decrement refcount */ | |
52 | #define pvcalls_exit() { \ | |
53 | atomic_dec(&pvcalls_refcount); \ | |
54 | } | |
55 | ||
56 | struct sock_mapping { | |
57 | bool active_socket; | |
58 | struct list_head list; | |
59 | struct socket *sock; | |
64d68718 | 60 | atomic_t refcount; |
cb1c7d9b SS |
61 | union { |
62 | struct { | |
63 | int irq; | |
64 | grant_ref_t ref; | |
65 | struct pvcalls_data_intf *ring; | |
66 | struct pvcalls_data data; | |
67 | struct mutex in_mutex; | |
68 | struct mutex out_mutex; | |
69 | ||
70 | wait_queue_head_t inflight_conn_req; | |
71 | } active; | |
67ea9893 | 72 | struct { |
d811bcee SS |
73 | /* |
74 | * Socket status, needs to be 64-bit aligned due to the | |
75 | * test_and_* functions which have this requirement on arm64. | |
76 | */ | |
67ea9893 SS |
77 | #define PVCALLS_STATUS_UNINITALIZED 0 |
78 | #define PVCALLS_STATUS_BIND 1 | |
79 | #define PVCALLS_STATUS_LISTEN 2 | |
d811bcee | 80 | uint8_t status __attribute__((aligned(8))); |
9774c6cc SS |
81 | /* |
82 | * Internal state-machine flags. | |
83 | * Only one accept operation can be inflight for a socket. | |
84 | * Only one poll operation can be inflight for a given socket. | |
d811bcee SS |
85 | * flags needs to be 64-bit aligned due to the test_and_* |
86 | * functions which have this requirement on arm64. | |
9774c6cc SS |
87 | */ |
88 | #define PVCALLS_FLAG_ACCEPT_INFLIGHT 0 | |
5842c835 SS |
89 | #define PVCALLS_FLAG_POLL_INFLIGHT 1 |
90 | #define PVCALLS_FLAG_POLL_RET 2 | |
d811bcee | 91 | uint8_t flags __attribute__((aligned(8))); |
9774c6cc SS |
92 | uint32_t inflight_req_id; |
93 | struct sock_mapping *accept_map; | |
94 | wait_queue_head_t inflight_accept_req; | |
67ea9893 | 95 | } passive; |
cb1c7d9b | 96 | }; |
aa7ba376 SS |
97 | }; |
98 | ||
64d68718 SS |
99 | static inline struct sock_mapping *pvcalls_enter_sock(struct socket *sock) |
100 | { | |
101 | struct sock_mapping *map; | |
102 | ||
103 | if (!pvcalls_front_dev || | |
104 | dev_get_drvdata(&pvcalls_front_dev->dev) == NULL) | |
105 | return ERR_PTR(-ENOTCONN); | |
106 | ||
107 | map = (struct sock_mapping *)sock->sk->sk_send_head; | |
108 | if (map == NULL) | |
109 | return ERR_PTR(-ENOTSOCK); | |
110 | ||
111 | pvcalls_enter(); | |
112 | atomic_inc(&map->refcount); | |
113 | return map; | |
114 | } | |
115 | ||
116 | static inline void pvcalls_exit_sock(struct socket *sock) | |
117 | { | |
118 | struct sock_mapping *map; | |
119 | ||
120 | map = (struct sock_mapping *)sock->sk->sk_send_head; | |
121 | atomic_dec(&map->refcount); | |
122 | pvcalls_exit(); | |
123 | } | |
124 | ||
2195046b SS |
125 | static inline int get_request(struct pvcalls_bedata *bedata, int *req_id) |
126 | { | |
127 | *req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1); | |
128 | if (RING_FULL(&bedata->ring) || | |
129 | bedata->rsp[*req_id].req_id != PVCALLS_INVALID_ID) | |
130 | return -EAGAIN; | |
131 | return 0; | |
132 | } | |
133 | ||
45ddce21 SS |
134 | static bool pvcalls_front_write_todo(struct sock_mapping *map) |
135 | { | |
136 | struct pvcalls_data_intf *intf = map->active.ring; | |
137 | RING_IDX cons, prod, size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
138 | int32_t error; | |
139 | ||
140 | error = intf->out_error; | |
141 | if (error == -ENOTCONN) | |
142 | return false; | |
143 | if (error != 0) | |
144 | return true; | |
145 | ||
146 | cons = intf->out_cons; | |
147 | prod = intf->out_prod; | |
148 | return !!(size - pvcalls_queued(prod, cons, size)); | |
149 | } | |
150 | ||
ae0d0405 SS |
151 | static bool pvcalls_front_read_todo(struct sock_mapping *map) |
152 | { | |
153 | struct pvcalls_data_intf *intf = map->active.ring; | |
154 | RING_IDX cons, prod; | |
155 | int32_t error; | |
156 | ||
157 | cons = intf->in_cons; | |
158 | prod = intf->in_prod; | |
159 | error = intf->in_error; | |
160 | return (error != 0 || | |
161 | pvcalls_queued(prod, cons, | |
162 | XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER)) != 0); | |
163 | } | |
164 | ||
aa7ba376 SS |
165 | static irqreturn_t pvcalls_front_event_handler(int irq, void *dev_id) |
166 | { | |
2195046b SS |
167 | struct xenbus_device *dev = dev_id; |
168 | struct pvcalls_bedata *bedata; | |
169 | struct xen_pvcalls_response *rsp; | |
170 | uint8_t *src, *dst; | |
171 | int req_id = 0, more = 0, done = 0; | |
172 | ||
173 | if (dev == NULL) | |
174 | return IRQ_HANDLED; | |
175 | ||
176 | pvcalls_enter(); | |
177 | bedata = dev_get_drvdata(&dev->dev); | |
178 | if (bedata == NULL) { | |
179 | pvcalls_exit(); | |
180 | return IRQ_HANDLED; | |
181 | } | |
182 | ||
183 | again: | |
184 | while (RING_HAS_UNCONSUMED_RESPONSES(&bedata->ring)) { | |
185 | rsp = RING_GET_RESPONSE(&bedata->ring, bedata->ring.rsp_cons); | |
186 | ||
187 | req_id = rsp->req_id; | |
5842c835 SS |
188 | if (rsp->cmd == PVCALLS_POLL) { |
189 | struct sock_mapping *map = (struct sock_mapping *)(uintptr_t) | |
190 | rsp->u.poll.id; | |
191 | ||
192 | clear_bit(PVCALLS_FLAG_POLL_INFLIGHT, | |
193 | (void *)&map->passive.flags); | |
194 | /* | |
195 | * clear INFLIGHT, then set RET. It pairs with | |
196 | * the checks at the beginning of | |
197 | * pvcalls_front_poll_passive. | |
198 | */ | |
199 | smp_wmb(); | |
200 | set_bit(PVCALLS_FLAG_POLL_RET, | |
201 | (void *)&map->passive.flags); | |
202 | } else { | |
203 | dst = (uint8_t *)&bedata->rsp[req_id] + | |
204 | sizeof(rsp->req_id); | |
205 | src = (uint8_t *)rsp + sizeof(rsp->req_id); | |
206 | memcpy(dst, src, sizeof(*rsp) - sizeof(rsp->req_id)); | |
207 | /* | |
208 | * First copy the rest of the data, then req_id. It is | |
209 | * paired with the barrier when accessing bedata->rsp. | |
210 | */ | |
211 | smp_wmb(); | |
212 | bedata->rsp[req_id].req_id = req_id; | |
213 | } | |
2195046b SS |
214 | |
215 | done = 1; | |
216 | bedata->ring.rsp_cons++; | |
217 | } | |
218 | ||
219 | RING_FINAL_CHECK_FOR_RESPONSES(&bedata->ring, more); | |
220 | if (more) | |
221 | goto again; | |
222 | if (done) | |
223 | wake_up(&bedata->inflight_req); | |
224 | pvcalls_exit(); | |
aa7ba376 SS |
225 | return IRQ_HANDLED; |
226 | } | |
227 | ||
f57034ce OM |
228 | static void free_active_ring(struct sock_mapping *map); |
229 | ||
c66bb48e JG |
230 | static void pvcalls_front_destroy_active(struct pvcalls_bedata *bedata, |
231 | struct sock_mapping *map) | |
aa7ba376 | 232 | { |
235a71c5 SS |
233 | int i; |
234 | ||
235 | unbind_from_irqhandler(map->active.irq, map); | |
236 | ||
c66bb48e JG |
237 | if (bedata) { |
238 | spin_lock(&bedata->socket_lock); | |
239 | if (!list_empty(&map->list)) | |
240 | list_del_init(&map->list); | |
241 | spin_unlock(&bedata->socket_lock); | |
242 | } | |
235a71c5 SS |
243 | |
244 | for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++) | |
49f8b459 JG |
245 | gnttab_end_foreign_access(map->active.ring->ref[i], NULL); |
246 | gnttab_end_foreign_access(map->active.ref, NULL); | |
f57034ce | 247 | free_active_ring(map); |
c66bb48e JG |
248 | } |
249 | ||
250 | static void pvcalls_front_free_map(struct pvcalls_bedata *bedata, | |
251 | struct sock_mapping *map) | |
252 | { | |
253 | pvcalls_front_destroy_active(bedata, map); | |
235a71c5 SS |
254 | |
255 | kfree(map); | |
aa7ba376 SS |
256 | } |
257 | ||
cb1c7d9b SS |
258 | static irqreturn_t pvcalls_front_conn_handler(int irq, void *sock_map) |
259 | { | |
260 | struct sock_mapping *map = sock_map; | |
261 | ||
262 | if (map == NULL) | |
263 | return IRQ_HANDLED; | |
264 | ||
265 | wake_up_interruptible(&map->active.inflight_conn_req); | |
266 | ||
267 | return IRQ_HANDLED; | |
268 | } | |
269 | ||
2195046b SS |
270 | int pvcalls_front_socket(struct socket *sock) |
271 | { | |
272 | struct pvcalls_bedata *bedata; | |
273 | struct sock_mapping *map = NULL; | |
274 | struct xen_pvcalls_request *req; | |
275 | int notify, req_id, ret; | |
276 | ||
277 | /* | |
278 | * PVCalls only supports domain AF_INET, | |
279 | * type SOCK_STREAM and protocol 0 sockets for now. | |
280 | * | |
281 | * Check socket type here, AF_INET and protocol checks are done | |
282 | * by the caller. | |
283 | */ | |
284 | if (sock->type != SOCK_STREAM) | |
285 | return -EOPNOTSUPP; | |
286 | ||
287 | pvcalls_enter(); | |
288 | if (!pvcalls_front_dev) { | |
289 | pvcalls_exit(); | |
290 | return -EACCES; | |
291 | } | |
292 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); | |
293 | ||
294 | map = kzalloc(sizeof(*map), GFP_KERNEL); | |
295 | if (map == NULL) { | |
296 | pvcalls_exit(); | |
297 | return -ENOMEM; | |
298 | } | |
299 | ||
300 | spin_lock(&bedata->socket_lock); | |
301 | ||
302 | ret = get_request(bedata, &req_id); | |
303 | if (ret < 0) { | |
304 | kfree(map); | |
305 | spin_unlock(&bedata->socket_lock); | |
306 | pvcalls_exit(); | |
307 | return ret; | |
308 | } | |
309 | ||
310 | /* | |
311 | * sock->sk->sk_send_head is not used for ip sockets: reuse the | |
312 | * field to store a pointer to the struct sock_mapping | |
313 | * corresponding to the socket. This way, we can easily get the | |
314 | * struct sock_mapping from the struct socket. | |
315 | */ | |
316 | sock->sk->sk_send_head = (void *)map; | |
317 | list_add_tail(&map->list, &bedata->socket_mappings); | |
318 | ||
319 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
320 | req->req_id = req_id; | |
321 | req->cmd = PVCALLS_SOCKET; | |
322 | req->u.socket.id = (uintptr_t) map; | |
323 | req->u.socket.domain = AF_INET; | |
324 | req->u.socket.type = SOCK_STREAM; | |
325 | req->u.socket.protocol = IPPROTO_IP; | |
326 | ||
327 | bedata->ring.req_prod_pvt++; | |
328 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
329 | spin_unlock(&bedata->socket_lock); | |
330 | if (notify) | |
331 | notify_remote_via_irq(bedata->irq); | |
332 | ||
333 | wait_event(bedata->inflight_req, | |
334 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
335 | ||
336 | /* read req_id, then the content */ | |
337 | smp_rmb(); | |
338 | ret = bedata->rsp[req_id].ret; | |
339 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
340 | ||
341 | pvcalls_exit(); | |
342 | return ret; | |
343 | } | |
344 | ||
9f51c05d WY |
345 | static void free_active_ring(struct sock_mapping *map) |
346 | { | |
b4711098 WY |
347 | if (!map->active.ring) |
348 | return; | |
349 | ||
b0576cc9 JG |
350 | free_pages_exact(map->active.data.in, |
351 | PAGE_SIZE << map->active.ring->ring_order); | |
9f51c05d WY |
352 | free_page((unsigned long)map->active.ring); |
353 | } | |
354 | ||
355 | static int alloc_active_ring(struct sock_mapping *map) | |
356 | { | |
357 | void *bytes; | |
358 | ||
359 | map->active.ring = (struct pvcalls_data_intf *) | |
360 | get_zeroed_page(GFP_KERNEL); | |
361 | if (!map->active.ring) | |
362 | goto out; | |
363 | ||
364 | map->active.ring->ring_order = PVCALLS_RING_ORDER; | |
b0576cc9 JG |
365 | bytes = alloc_pages_exact(PAGE_SIZE << PVCALLS_RING_ORDER, |
366 | GFP_KERNEL | __GFP_ZERO); | |
9f51c05d WY |
367 | if (!bytes) |
368 | goto out; | |
369 | ||
370 | map->active.data.in = bytes; | |
371 | map->active.data.out = bytes + | |
372 | XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
373 | ||
374 | return 0; | |
375 | ||
376 | out: | |
377 | free_active_ring(map); | |
378 | return -ENOMEM; | |
379 | } | |
380 | ||
0102e4ef | 381 | static int create_active(struct sock_mapping *map, evtchn_port_t *evtchn) |
cb1c7d9b SS |
382 | { |
383 | void *bytes; | |
bba91dd6 | 384 | int ret, irq = -1, i; |
cb1c7d9b | 385 | |
0102e4ef | 386 | *evtchn = 0; |
cb1c7d9b SS |
387 | init_waitqueue_head(&map->active.inflight_conn_req); |
388 | ||
9f51c05d | 389 | bytes = map->active.data.in; |
cb1c7d9b SS |
390 | for (i = 0; i < (1 << PVCALLS_RING_ORDER); i++) |
391 | map->active.ring->ref[i] = gnttab_grant_foreign_access( | |
392 | pvcalls_front_dev->otherend_id, | |
393 | pfn_to_gfn(virt_to_pfn(bytes) + i), 0); | |
394 | ||
395 | map->active.ref = gnttab_grant_foreign_access( | |
396 | pvcalls_front_dev->otherend_id, | |
397 | pfn_to_gfn(virt_to_pfn((void *)map->active.ring)), 0); | |
398 | ||
cb1c7d9b SS |
399 | ret = xenbus_alloc_evtchn(pvcalls_front_dev, evtchn); |
400 | if (ret) | |
401 | goto out_error; | |
402 | irq = bind_evtchn_to_irqhandler(*evtchn, pvcalls_front_conn_handler, | |
403 | 0, "pvcalls-frontend", map); | |
404 | if (irq < 0) { | |
405 | ret = irq; | |
406 | goto out_error; | |
407 | } | |
408 | ||
409 | map->active.irq = irq; | |
410 | map->active_socket = true; | |
411 | mutex_init(&map->active.in_mutex); | |
412 | mutex_init(&map->active.out_mutex); | |
413 | ||
414 | return 0; | |
415 | ||
416 | out_error: | |
0102e4ef | 417 | if (*evtchn > 0) |
cb1c7d9b | 418 | xenbus_free_evtchn(pvcalls_front_dev, *evtchn); |
cb1c7d9b SS |
419 | return ret; |
420 | } | |
421 | ||
422 | int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr, | |
423 | int addr_len, int flags) | |
424 | { | |
425 | struct pvcalls_bedata *bedata; | |
426 | struct sock_mapping *map = NULL; | |
427 | struct xen_pvcalls_request *req; | |
0102e4ef YY |
428 | int notify, req_id, ret; |
429 | evtchn_port_t evtchn; | |
cb1c7d9b SS |
430 | |
431 | if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM) | |
432 | return -EOPNOTSUPP; | |
433 | ||
64d68718 SS |
434 | map = pvcalls_enter_sock(sock); |
435 | if (IS_ERR(map)) | |
436 | return PTR_ERR(map); | |
cb1c7d9b SS |
437 | |
438 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); | |
9f51c05d WY |
439 | ret = alloc_active_ring(map); |
440 | if (ret < 0) { | |
441 | pvcalls_exit_sock(sock); | |
442 | return ret; | |
443 | } | |
c66bb48e | 444 | ret = create_active(map, &evtchn); |
cb1c7d9b | 445 | if (ret < 0) { |
9f51c05d | 446 | free_active_ring(map); |
64d68718 | 447 | pvcalls_exit_sock(sock); |
cb1c7d9b SS |
448 | return ret; |
449 | } | |
c66bb48e JG |
450 | |
451 | spin_lock(&bedata->socket_lock); | |
452 | ret = get_request(bedata, &req_id); | |
cb1c7d9b SS |
453 | if (ret < 0) { |
454 | spin_unlock(&bedata->socket_lock); | |
c66bb48e | 455 | pvcalls_front_destroy_active(NULL, map); |
64d68718 | 456 | pvcalls_exit_sock(sock); |
cb1c7d9b SS |
457 | return ret; |
458 | } | |
459 | ||
460 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
461 | req->req_id = req_id; | |
462 | req->cmd = PVCALLS_CONNECT; | |
463 | req->u.connect.id = (uintptr_t)map; | |
464 | req->u.connect.len = addr_len; | |
465 | req->u.connect.flags = flags; | |
466 | req->u.connect.ref = map->active.ref; | |
467 | req->u.connect.evtchn = evtchn; | |
468 | memcpy(req->u.connect.addr, addr, sizeof(*addr)); | |
469 | ||
470 | map->sock = sock; | |
471 | ||
472 | bedata->ring.req_prod_pvt++; | |
473 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
474 | spin_unlock(&bedata->socket_lock); | |
475 | ||
476 | if (notify) | |
477 | notify_remote_via_irq(bedata->irq); | |
478 | ||
479 | wait_event(bedata->inflight_req, | |
480 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
481 | ||
482 | /* read req_id, then the content */ | |
483 | smp_rmb(); | |
484 | ret = bedata->rsp[req_id].ret; | |
485 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
64d68718 | 486 | pvcalls_exit_sock(sock); |
cb1c7d9b SS |
487 | return ret; |
488 | } | |
489 | ||
45ddce21 SS |
490 | static int __write_ring(struct pvcalls_data_intf *intf, |
491 | struct pvcalls_data *data, | |
492 | struct iov_iter *msg_iter, | |
493 | int len) | |
494 | { | |
495 | RING_IDX cons, prod, size, masked_prod, masked_cons; | |
496 | RING_IDX array_size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
497 | int32_t error; | |
498 | ||
499 | error = intf->out_error; | |
500 | if (error < 0) | |
501 | return error; | |
502 | cons = intf->out_cons; | |
503 | prod = intf->out_prod; | |
504 | /* read indexes before continuing */ | |
505 | virt_mb(); | |
506 | ||
507 | size = pvcalls_queued(prod, cons, array_size); | |
d90a1ca6 | 508 | if (size > array_size) |
45ddce21 | 509 | return -EINVAL; |
d90a1ca6 SS |
510 | if (size == array_size) |
511 | return 0; | |
45ddce21 SS |
512 | if (len > array_size - size) |
513 | len = array_size - size; | |
514 | ||
515 | masked_prod = pvcalls_mask(prod, array_size); | |
516 | masked_cons = pvcalls_mask(cons, array_size); | |
517 | ||
518 | if (masked_prod < masked_cons) { | |
519 | len = copy_from_iter(data->out + masked_prod, len, msg_iter); | |
520 | } else { | |
521 | if (len > array_size - masked_prod) { | |
522 | int ret = copy_from_iter(data->out + masked_prod, | |
523 | array_size - masked_prod, msg_iter); | |
524 | if (ret != array_size - masked_prod) { | |
525 | len = ret; | |
526 | goto out; | |
527 | } | |
528 | len = ret + copy_from_iter(data->out, len - ret, msg_iter); | |
529 | } else { | |
530 | len = copy_from_iter(data->out + masked_prod, len, msg_iter); | |
531 | } | |
532 | } | |
533 | out: | |
534 | /* write to ring before updating pointer */ | |
535 | virt_wmb(); | |
536 | intf->out_prod += len; | |
537 | ||
538 | return len; | |
539 | } | |
540 | ||
541 | int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg, | |
542 | size_t len) | |
543 | { | |
45ddce21 SS |
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 | 555 | |
45ddce21 SS |
556 | mutex_lock(&map->active.out_mutex); |
557 | if ((flags & MSG_DONTWAIT) && !pvcalls_front_write_todo(map)) { | |
558 | mutex_unlock(&map->active.out_mutex); | |
64d68718 | 559 | pvcalls_exit_sock(sock); |
45ddce21 SS |
560 | return -EAGAIN; |
561 | } | |
562 | if (len > INT_MAX) | |
563 | len = INT_MAX; | |
564 | ||
565 | again: | |
566 | count++; | |
567 | sent = __write_ring(map->active.ring, | |
568 | &map->active.data, &msg->msg_iter, | |
569 | len); | |
570 | if (sent > 0) { | |
571 | len -= sent; | |
572 | tot_sent += sent; | |
573 | notify_remote_via_irq(map->active.irq); | |
574 | } | |
575 | if (sent >= 0 && len > 0 && count < PVCALLS_FRONT_MAX_SPIN) | |
576 | goto again; | |
577 | if (sent < 0) | |
578 | tot_sent = sent; | |
579 | ||
580 | mutex_unlock(&map->active.out_mutex); | |
64d68718 | 581 | pvcalls_exit_sock(sock); |
45ddce21 SS |
582 | return tot_sent; |
583 | } | |
584 | ||
ae0d0405 SS |
585 | static int __read_ring(struct pvcalls_data_intf *intf, |
586 | struct pvcalls_data *data, | |
587 | struct iov_iter *msg_iter, | |
588 | size_t len, int flags) | |
589 | { | |
590 | RING_IDX cons, prod, size, masked_prod, masked_cons; | |
591 | RING_IDX array_size = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
592 | int32_t error; | |
593 | ||
594 | cons = intf->in_cons; | |
595 | prod = intf->in_prod; | |
596 | error = intf->in_error; | |
597 | /* get pointers before reading from the ring */ | |
598 | virt_rmb(); | |
ae0d0405 SS |
599 | |
600 | size = pvcalls_queued(prod, cons, array_size); | |
601 | masked_prod = pvcalls_mask(prod, array_size); | |
602 | masked_cons = pvcalls_mask(cons, array_size); | |
603 | ||
604 | if (size == 0) | |
b79470b6 | 605 | return error ?: size; |
ae0d0405 SS |
606 | |
607 | if (len > size) | |
608 | len = size; | |
609 | ||
610 | if (masked_prod > masked_cons) { | |
611 | len = copy_to_iter(data->in + masked_cons, len, msg_iter); | |
612 | } else { | |
613 | if (len > (array_size - masked_cons)) { | |
614 | int ret = copy_to_iter(data->in + masked_cons, | |
615 | array_size - masked_cons, msg_iter); | |
616 | if (ret != array_size - masked_cons) { | |
617 | len = ret; | |
618 | goto out; | |
619 | } | |
620 | len = ret + copy_to_iter(data->in, len - ret, msg_iter); | |
621 | } else { | |
622 | len = copy_to_iter(data->in + masked_cons, len, msg_iter); | |
623 | } | |
624 | } | |
625 | out: | |
626 | /* read data from the ring before increasing the index */ | |
627 | virt_mb(); | |
628 | if (!(flags & MSG_PEEK)) | |
629 | intf->in_cons += len; | |
630 | ||
631 | return len; | |
632 | } | |
633 | ||
634 | int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, | |
635 | int flags) | |
636 | { | |
ae0d0405 SS |
637 | int ret; |
638 | struct sock_mapping *map; | |
639 | ||
640 | if (flags & (MSG_CMSG_CLOEXEC|MSG_ERRQUEUE|MSG_OOB|MSG_TRUNC)) | |
641 | return -EOPNOTSUPP; | |
642 | ||
64d68718 SS |
643 | map = pvcalls_enter_sock(sock); |
644 | if (IS_ERR(map)) | |
645 | return PTR_ERR(map); | |
ae0d0405 | 646 | |
ae0d0405 SS |
647 | mutex_lock(&map->active.in_mutex); |
648 | if (len > XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER)) | |
649 | len = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER); | |
650 | ||
651 | while (!(flags & MSG_DONTWAIT) && !pvcalls_front_read_todo(map)) { | |
652 | wait_event_interruptible(map->active.inflight_conn_req, | |
653 | pvcalls_front_read_todo(map)); | |
654 | } | |
655 | ret = __read_ring(map->active.ring, &map->active.data, | |
656 | &msg->msg_iter, len, flags); | |
657 | ||
658 | if (ret > 0) | |
659 | notify_remote_via_irq(map->active.irq); | |
660 | if (ret == 0) | |
661 | ret = (flags & MSG_DONTWAIT) ? -EAGAIN : 0; | |
662 | if (ret == -ENOTCONN) | |
663 | ret = 0; | |
664 | ||
665 | mutex_unlock(&map->active.in_mutex); | |
64d68718 | 666 | pvcalls_exit_sock(sock); |
ae0d0405 SS |
667 | return ret; |
668 | } | |
669 | ||
67ea9893 SS |
670 | int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len) |
671 | { | |
672 | struct pvcalls_bedata *bedata; | |
673 | struct sock_mapping *map = NULL; | |
674 | struct xen_pvcalls_request *req; | |
675 | int notify, req_id, ret; | |
676 | ||
677 | if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM) | |
678 | return -EOPNOTSUPP; | |
679 | ||
64d68718 SS |
680 | map = pvcalls_enter_sock(sock); |
681 | if (IS_ERR(map)) | |
682 | return PTR_ERR(map); | |
67ea9893 SS |
683 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
684 | ||
67ea9893 SS |
685 | spin_lock(&bedata->socket_lock); |
686 | ret = get_request(bedata, &req_id); | |
687 | if (ret < 0) { | |
688 | spin_unlock(&bedata->socket_lock); | |
64d68718 | 689 | pvcalls_exit_sock(sock); |
67ea9893 SS |
690 | return ret; |
691 | } | |
692 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
693 | req->req_id = req_id; | |
694 | map->sock = sock; | |
695 | req->cmd = PVCALLS_BIND; | |
696 | req->u.bind.id = (uintptr_t)map; | |
697 | memcpy(req->u.bind.addr, addr, sizeof(*addr)); | |
698 | req->u.bind.len = addr_len; | |
699 | ||
9774c6cc SS |
700 | init_waitqueue_head(&map->passive.inflight_accept_req); |
701 | ||
67ea9893 SS |
702 | map->active_socket = false; |
703 | ||
704 | bedata->ring.req_prod_pvt++; | |
705 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
706 | spin_unlock(&bedata->socket_lock); | |
707 | if (notify) | |
708 | notify_remote_via_irq(bedata->irq); | |
709 | ||
710 | wait_event(bedata->inflight_req, | |
711 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
712 | ||
713 | /* read req_id, then the content */ | |
714 | smp_rmb(); | |
715 | ret = bedata->rsp[req_id].ret; | |
716 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
717 | ||
718 | map->passive.status = PVCALLS_STATUS_BIND; | |
64d68718 | 719 | pvcalls_exit_sock(sock); |
67ea9893 SS |
720 | return 0; |
721 | } | |
722 | ||
1853f11d SS |
723 | int pvcalls_front_listen(struct socket *sock, int backlog) |
724 | { | |
725 | struct pvcalls_bedata *bedata; | |
726 | struct sock_mapping *map; | |
727 | struct xen_pvcalls_request *req; | |
728 | int notify, req_id, ret; | |
729 | ||
64d68718 SS |
730 | map = pvcalls_enter_sock(sock); |
731 | if (IS_ERR(map)) | |
732 | return PTR_ERR(map); | |
1853f11d SS |
733 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
734 | ||
1853f11d | 735 | if (map->passive.status != PVCALLS_STATUS_BIND) { |
64d68718 | 736 | pvcalls_exit_sock(sock); |
1853f11d SS |
737 | return -EOPNOTSUPP; |
738 | } | |
739 | ||
740 | spin_lock(&bedata->socket_lock); | |
741 | ret = get_request(bedata, &req_id); | |
742 | if (ret < 0) { | |
743 | spin_unlock(&bedata->socket_lock); | |
64d68718 | 744 | pvcalls_exit_sock(sock); |
1853f11d SS |
745 | return ret; |
746 | } | |
747 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
748 | req->req_id = req_id; | |
749 | req->cmd = PVCALLS_LISTEN; | |
750 | req->u.listen.id = (uintptr_t) map; | |
751 | req->u.listen.backlog = backlog; | |
752 | ||
753 | bedata->ring.req_prod_pvt++; | |
754 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
755 | spin_unlock(&bedata->socket_lock); | |
756 | if (notify) | |
757 | notify_remote_via_irq(bedata->irq); | |
758 | ||
759 | wait_event(bedata->inflight_req, | |
760 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
761 | ||
762 | /* read req_id, then the content */ | |
763 | smp_rmb(); | |
764 | ret = bedata->rsp[req_id].ret; | |
765 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
766 | ||
767 | map->passive.status = PVCALLS_STATUS_LISTEN; | |
64d68718 | 768 | pvcalls_exit_sock(sock); |
1853f11d SS |
769 | return ret; |
770 | } | |
771 | ||
9774c6cc SS |
772 | int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags) |
773 | { | |
774 | struct pvcalls_bedata *bedata; | |
775 | struct sock_mapping *map; | |
776 | struct sock_mapping *map2 = NULL; | |
777 | struct xen_pvcalls_request *req; | |
0102e4ef YY |
778 | int notify, req_id, ret, nonblock; |
779 | evtchn_port_t evtchn; | |
9774c6cc | 780 | |
64d68718 SS |
781 | map = pvcalls_enter_sock(sock); |
782 | if (IS_ERR(map)) | |
783 | return PTR_ERR(map); | |
9774c6cc SS |
784 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
785 | ||
9774c6cc | 786 | if (map->passive.status != PVCALLS_STATUS_LISTEN) { |
64d68718 | 787 | pvcalls_exit_sock(sock); |
9774c6cc SS |
788 | return -EINVAL; |
789 | } | |
790 | ||
791 | nonblock = flags & SOCK_NONBLOCK; | |
792 | /* | |
793 | * Backend only supports 1 inflight accept request, will return | |
794 | * errors for the others | |
795 | */ | |
796 | if (test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
797 | (void *)&map->passive.flags)) { | |
798 | req_id = READ_ONCE(map->passive.inflight_req_id); | |
799 | if (req_id != PVCALLS_INVALID_ID && | |
800 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id) { | |
801 | map2 = map->passive.accept_map; | |
802 | goto received; | |
803 | } | |
804 | if (nonblock) { | |
64d68718 | 805 | pvcalls_exit_sock(sock); |
9774c6cc SS |
806 | return -EAGAIN; |
807 | } | |
808 | if (wait_event_interruptible(map->passive.inflight_accept_req, | |
809 | !test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
810 | (void *)&map->passive.flags))) { | |
64d68718 | 811 | pvcalls_exit_sock(sock); |
9774c6cc SS |
812 | return -EINTR; |
813 | } | |
814 | } | |
815 | ||
9f51c05d WY |
816 | map2 = kzalloc(sizeof(*map2), GFP_KERNEL); |
817 | if (map2 == NULL) { | |
9774c6cc SS |
818 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, |
819 | (void *)&map->passive.flags); | |
9f51c05d WY |
820 | pvcalls_exit_sock(sock); |
821 | return -ENOMEM; | |
822 | } | |
823 | ret = alloc_active_ring(map2); | |
824 | if (ret < 0) { | |
825 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
826 | (void *)&map->passive.flags); | |
827 | kfree(map2); | |
64d68718 | 828 | pvcalls_exit_sock(sock); |
9774c6cc SS |
829 | return ret; |
830 | } | |
c66bb48e | 831 | ret = create_active(map2, &evtchn); |
9f51c05d | 832 | if (ret < 0) { |
9f51c05d WY |
833 | free_active_ring(map2); |
834 | kfree(map2); | |
c66bb48e JG |
835 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, |
836 | (void *)&map->passive.flags); | |
64d68718 | 837 | pvcalls_exit_sock(sock); |
9f51c05d | 838 | return ret; |
9774c6cc | 839 | } |
9f51c05d | 840 | |
c66bb48e JG |
841 | spin_lock(&bedata->socket_lock); |
842 | ret = get_request(bedata, &req_id); | |
9774c6cc | 843 | if (ret < 0) { |
9774c6cc SS |
844 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, |
845 | (void *)&map->passive.flags); | |
846 | spin_unlock(&bedata->socket_lock); | |
c66bb48e | 847 | pvcalls_front_free_map(bedata, map2); |
64d68718 | 848 | pvcalls_exit_sock(sock); |
9774c6cc SS |
849 | return ret; |
850 | } | |
c66bb48e | 851 | |
9774c6cc SS |
852 | list_add_tail(&map2->list, &bedata->socket_mappings); |
853 | ||
854 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
855 | req->req_id = req_id; | |
856 | req->cmd = PVCALLS_ACCEPT; | |
857 | req->u.accept.id = (uintptr_t) map; | |
858 | req->u.accept.ref = map2->active.ref; | |
859 | req->u.accept.id_new = (uintptr_t) map2; | |
860 | req->u.accept.evtchn = evtchn; | |
861 | map->passive.accept_map = map2; | |
862 | ||
863 | bedata->ring.req_prod_pvt++; | |
864 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
865 | spin_unlock(&bedata->socket_lock); | |
866 | if (notify) | |
867 | notify_remote_via_irq(bedata->irq); | |
868 | /* We could check if we have received a response before returning. */ | |
869 | if (nonblock) { | |
870 | WRITE_ONCE(map->passive.inflight_req_id, req_id); | |
64d68718 | 871 | pvcalls_exit_sock(sock); |
9774c6cc SS |
872 | return -EAGAIN; |
873 | } | |
874 | ||
875 | if (wait_event_interruptible(bedata->inflight_req, | |
876 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id)) { | |
64d68718 | 877 | pvcalls_exit_sock(sock); |
9774c6cc SS |
878 | return -EINTR; |
879 | } | |
880 | /* read req_id, then the content */ | |
881 | smp_rmb(); | |
882 | ||
883 | received: | |
884 | map2->sock = newsock; | |
beee1fbe | 885 | newsock->sk = sk_alloc(sock_net(sock->sk), PF_INET, GFP_KERNEL, &pvcalls_proto, false); |
9774c6cc SS |
886 | if (!newsock->sk) { |
887 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
888 | map->passive.inflight_req_id = PVCALLS_INVALID_ID; | |
889 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
890 | (void *)&map->passive.flags); | |
891 | pvcalls_front_free_map(bedata, map2); | |
64d68718 | 892 | pvcalls_exit_sock(sock); |
9774c6cc SS |
893 | return -ENOMEM; |
894 | } | |
895 | newsock->sk->sk_send_head = (void *)map2; | |
896 | ||
897 | ret = bedata->rsp[req_id].ret; | |
898 | bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID; | |
899 | map->passive.inflight_req_id = PVCALLS_INVALID_ID; | |
900 | ||
901 | clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, (void *)&map->passive.flags); | |
902 | wake_up(&map->passive.inflight_accept_req); | |
903 | ||
64d68718 | 904 | pvcalls_exit_sock(sock); |
9774c6cc SS |
905 | return ret; |
906 | } | |
907 | ||
afc9a42b | 908 | static __poll_t pvcalls_front_poll_passive(struct file *file, |
5842c835 SS |
909 | struct pvcalls_bedata *bedata, |
910 | struct sock_mapping *map, | |
911 | poll_table *wait) | |
912 | { | |
913 | int notify, req_id, ret; | |
914 | struct xen_pvcalls_request *req; | |
915 | ||
916 | if (test_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, | |
917 | (void *)&map->passive.flags)) { | |
918 | uint32_t req_id = READ_ONCE(map->passive.inflight_req_id); | |
919 | ||
920 | if (req_id != PVCALLS_INVALID_ID && | |
921 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id) | |
a9a08845 | 922 | return EPOLLIN | EPOLLRDNORM; |
5842c835 SS |
923 | |
924 | poll_wait(file, &map->passive.inflight_accept_req, wait); | |
925 | return 0; | |
926 | } | |
927 | ||
928 | if (test_and_clear_bit(PVCALLS_FLAG_POLL_RET, | |
929 | (void *)&map->passive.flags)) | |
a9a08845 | 930 | return EPOLLIN | EPOLLRDNORM; |
5842c835 SS |
931 | |
932 | /* | |
933 | * First check RET, then INFLIGHT. No barriers necessary to | |
934 | * ensure execution ordering because of the conditional | |
935 | * instructions creating control dependencies. | |
936 | */ | |
937 | ||
938 | if (test_and_set_bit(PVCALLS_FLAG_POLL_INFLIGHT, | |
939 | (void *)&map->passive.flags)) { | |
940 | poll_wait(file, &bedata->inflight_req, wait); | |
941 | return 0; | |
942 | } | |
943 | ||
944 | spin_lock(&bedata->socket_lock); | |
945 | ret = get_request(bedata, &req_id); | |
946 | if (ret < 0) { | |
947 | spin_unlock(&bedata->socket_lock); | |
948 | return ret; | |
949 | } | |
950 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
951 | req->req_id = req_id; | |
952 | req->cmd = PVCALLS_POLL; | |
953 | req->u.poll.id = (uintptr_t) map; | |
954 | ||
955 | bedata->ring.req_prod_pvt++; | |
956 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
957 | spin_unlock(&bedata->socket_lock); | |
958 | if (notify) | |
959 | notify_remote_via_irq(bedata->irq); | |
960 | ||
961 | poll_wait(file, &bedata->inflight_req, wait); | |
962 | return 0; | |
963 | } | |
964 | ||
afc9a42b | 965 | static __poll_t pvcalls_front_poll_active(struct file *file, |
5842c835 SS |
966 | struct pvcalls_bedata *bedata, |
967 | struct sock_mapping *map, | |
968 | poll_table *wait) | |
969 | { | |
afc9a42b | 970 | __poll_t mask = 0; |
5842c835 SS |
971 | int32_t in_error, out_error; |
972 | struct pvcalls_data_intf *intf = map->active.ring; | |
973 | ||
974 | out_error = intf->out_error; | |
975 | in_error = intf->in_error; | |
976 | ||
977 | poll_wait(file, &map->active.inflight_conn_req, wait); | |
978 | if (pvcalls_front_write_todo(map)) | |
a9a08845 | 979 | mask |= EPOLLOUT | EPOLLWRNORM; |
5842c835 | 980 | if (pvcalls_front_read_todo(map)) |
a9a08845 | 981 | mask |= EPOLLIN | EPOLLRDNORM; |
5842c835 | 982 | if (in_error != 0 || out_error != 0) |
a9a08845 | 983 | mask |= EPOLLERR; |
5842c835 SS |
984 | |
985 | return mask; | |
986 | } | |
987 | ||
afc9a42b | 988 | __poll_t pvcalls_front_poll(struct file *file, struct socket *sock, |
5842c835 SS |
989 | poll_table *wait) |
990 | { | |
991 | struct pvcalls_bedata *bedata; | |
992 | struct sock_mapping *map; | |
afc9a42b | 993 | __poll_t ret; |
5842c835 | 994 | |
64d68718 SS |
995 | map = pvcalls_enter_sock(sock); |
996 | if (IS_ERR(map)) | |
a9a08845 | 997 | return EPOLLNVAL; |
5842c835 SS |
998 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
999 | ||
5842c835 SS |
1000 | if (map->active_socket) |
1001 | ret = pvcalls_front_poll_active(file, bedata, map, wait); | |
1002 | else | |
1003 | ret = pvcalls_front_poll_passive(file, bedata, map, wait); | |
64d68718 | 1004 | pvcalls_exit_sock(sock); |
5842c835 SS |
1005 | return ret; |
1006 | } | |
1007 | ||
235a71c5 SS |
1008 | int pvcalls_front_release(struct socket *sock) |
1009 | { | |
1010 | struct pvcalls_bedata *bedata; | |
1011 | struct sock_mapping *map; | |
1012 | int req_id, notify, ret; | |
1013 | struct xen_pvcalls_request *req; | |
1014 | ||
1015 | if (sock->sk == NULL) | |
1016 | return 0; | |
1017 | ||
64d68718 SS |
1018 | map = pvcalls_enter_sock(sock); |
1019 | if (IS_ERR(map)) { | |
1020 | if (PTR_ERR(map) == -ENOTCONN) | |
1021 | return -EIO; | |
1022 | else | |
1023 | return 0; | |
235a71c5 | 1024 | } |
235a71c5 SS |
1025 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); |
1026 | ||
235a71c5 SS |
1027 | spin_lock(&bedata->socket_lock); |
1028 | ret = get_request(bedata, &req_id); | |
1029 | if (ret < 0) { | |
1030 | spin_unlock(&bedata->socket_lock); | |
64d68718 | 1031 | pvcalls_exit_sock(sock); |
235a71c5 SS |
1032 | return ret; |
1033 | } | |
1034 | sock->sk->sk_send_head = NULL; | |
1035 | ||
1036 | req = RING_GET_REQUEST(&bedata->ring, req_id); | |
1037 | req->req_id = req_id; | |
1038 | req->cmd = PVCALLS_RELEASE; | |
1039 | req->u.release.id = (uintptr_t)map; | |
1040 | ||
1041 | bedata->ring.req_prod_pvt++; | |
1042 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); | |
1043 | spin_unlock(&bedata->socket_lock); | |
1044 | if (notify) | |
1045 | notify_remote_via_irq(bedata->irq); | |
1046 | ||
1047 | wait_event(bedata->inflight_req, | |
1048 | READ_ONCE(bedata->rsp[req_id].req_id) == req_id); | |
1049 | ||
1050 | if (map->active_socket) { | |
1051 | /* | |
1052 | * Set in_error and wake up inflight_conn_req to force | |
1053 | * recvmsg waiters to exit. | |
1054 | */ | |
1055 | map->active.ring->in_error = -EBADF; | |
1056 | wake_up_interruptible(&map->active.inflight_conn_req); | |
1057 | ||
1058 | /* | |
646d944c SS |
1059 | * We need to make sure that sendmsg/recvmsg on this socket have |
1060 | * not started before we've cleared sk_send_head here. The | |
64d68718 SS |
1061 | * easiest way to guarantee this is to see that no pvcalls |
1062 | * (other than us) is in progress on this socket. | |
235a71c5 | 1063 | */ |
64d68718 | 1064 | while (atomic_read(&map->refcount) > 1) |
235a71c5 SS |
1065 | cpu_relax(); |
1066 | ||
1067 | pvcalls_front_free_map(bedata, map); | |
1068 | } else { | |
d1a75e08 SS |
1069 | wake_up(&bedata->inflight_req); |
1070 | wake_up(&map->passive.inflight_accept_req); | |
1071 | ||
1072 | while (atomic_read(&map->refcount) > 1) | |
1073 | cpu_relax(); | |
1074 | ||
235a71c5 SS |
1075 | spin_lock(&bedata->socket_lock); |
1076 | list_del(&map->list); | |
1077 | spin_unlock(&bedata->socket_lock); | |
96283f9a SS |
1078 | if (READ_ONCE(map->passive.inflight_req_id) != PVCALLS_INVALID_ID && |
1079 | READ_ONCE(map->passive.inflight_req_id) != 0) { | |
235a71c5 SS |
1080 | pvcalls_front_free_map(bedata, |
1081 | map->passive.accept_map); | |
1082 | } | |
1083 | kfree(map); | |
1084 | } | |
1085 | WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID); | |
1086 | ||
1087 | pvcalls_exit(); | |
1088 | return 0; | |
1089 | } | |
1090 | ||
416efba0 SS |
1091 | static const struct xenbus_device_id pvcalls_front_ids[] = { |
1092 | { "pvcalls" }, | |
1093 | { "" } | |
1094 | }; | |
1095 | ||
7cffcade | 1096 | static void pvcalls_front_remove(struct xenbus_device *dev) |
416efba0 | 1097 | { |
aa7ba376 SS |
1098 | struct pvcalls_bedata *bedata; |
1099 | struct sock_mapping *map = NULL, *n; | |
1100 | ||
1101 | bedata = dev_get_drvdata(&pvcalls_front_dev->dev); | |
1102 | dev_set_drvdata(&dev->dev, NULL); | |
1103 | pvcalls_front_dev = NULL; | |
1104 | if (bedata->irq >= 0) | |
1105 | unbind_from_irqhandler(bedata->irq, dev); | |
1106 | ||
cb1c7d9b SS |
1107 | list_for_each_entry_safe(map, n, &bedata->socket_mappings, list) { |
1108 | map->sock->sk->sk_send_head = NULL; | |
1109 | if (map->active_socket) { | |
1110 | map->active.ring->in_error = -EBADF; | |
1111 | wake_up_interruptible(&map->active.inflight_conn_req); | |
1112 | } | |
1113 | } | |
1114 | ||
aa7ba376 SS |
1115 | smp_mb(); |
1116 | while (atomic_read(&pvcalls_refcount) > 0) | |
1117 | cpu_relax(); | |
1118 | list_for_each_entry_safe(map, n, &bedata->socket_mappings, list) { | |
1119 | if (map->active_socket) { | |
1120 | /* No need to lock, refcount is 0 */ | |
1121 | pvcalls_front_free_map(bedata, map); | |
1122 | } else { | |
1123 | list_del(&map->list); | |
1124 | kfree(map); | |
1125 | } | |
1126 | } | |
1ab134ca | 1127 | if (bedata->ref != -1) |
49f8b459 | 1128 | gnttab_end_foreign_access(bedata->ref, NULL); |
aa7ba376 SS |
1129 | kfree(bedata->ring.sring); |
1130 | kfree(bedata); | |
1131 | xenbus_switch_state(dev, XenbusStateClosed); | |
416efba0 SS |
1132 | } |
1133 | ||
1134 | static int pvcalls_front_probe(struct xenbus_device *dev, | |
1135 | const struct xenbus_device_id *id) | |
1136 | { | |
0102e4ef YY |
1137 | int ret = -ENOMEM, i; |
1138 | evtchn_port_t evtchn; | |
21968190 SS |
1139 | unsigned int max_page_order, function_calls, len; |
1140 | char *versions; | |
1141 | grant_ref_t gref_head = 0; | |
1142 | struct xenbus_transaction xbt; | |
1143 | struct pvcalls_bedata *bedata = NULL; | |
1144 | struct xen_pvcalls_sring *sring; | |
1145 | ||
1146 | if (pvcalls_front_dev != NULL) { | |
1147 | dev_err(&dev->dev, "only one PV Calls connection supported\n"); | |
1148 | return -EINVAL; | |
1149 | } | |
1150 | ||
1151 | versions = xenbus_read(XBT_NIL, dev->otherend, "versions", &len); | |
8c71fa88 DC |
1152 | if (IS_ERR(versions)) |
1153 | return PTR_ERR(versions); | |
21968190 SS |
1154 | if (!len) |
1155 | return -EINVAL; | |
1156 | if (strcmp(versions, "1")) { | |
1157 | kfree(versions); | |
1158 | return -EINVAL; | |
1159 | } | |
1160 | kfree(versions); | |
1161 | max_page_order = xenbus_read_unsigned(dev->otherend, | |
1162 | "max-page-order", 0); | |
1163 | if (max_page_order < PVCALLS_RING_ORDER) | |
1164 | return -ENODEV; | |
1165 | function_calls = xenbus_read_unsigned(dev->otherend, | |
1166 | "function-calls", 0); | |
1167 | /* See XENBUS_FUNCTIONS_CALLS in pvcalls.h */ | |
1168 | if (function_calls != 1) | |
1169 | return -ENODEV; | |
1170 | pr_info("%s max-page-order is %u\n", __func__, max_page_order); | |
1171 | ||
1172 | bedata = kzalloc(sizeof(struct pvcalls_bedata), GFP_KERNEL); | |
1173 | if (!bedata) | |
1174 | return -ENOMEM; | |
1175 | ||
1176 | dev_set_drvdata(&dev->dev, bedata); | |
1177 | pvcalls_front_dev = dev; | |
1178 | init_waitqueue_head(&bedata->inflight_req); | |
1179 | INIT_LIST_HEAD(&bedata->socket_mappings); | |
1180 | spin_lock_init(&bedata->socket_lock); | |
1181 | bedata->irq = -1; | |
1182 | bedata->ref = -1; | |
1183 | ||
1184 | for (i = 0; i < PVCALLS_NR_RSP_PER_RING; i++) | |
1185 | bedata->rsp[i].req_id = PVCALLS_INVALID_ID; | |
1186 | ||
1187 | sring = (struct xen_pvcalls_sring *) __get_free_page(GFP_KERNEL | | |
1188 | __GFP_ZERO); | |
1189 | if (!sring) | |
1190 | goto error; | |
1191 | SHARED_RING_INIT(sring); | |
1192 | FRONT_RING_INIT(&bedata->ring, sring, XEN_PAGE_SIZE); | |
1193 | ||
1194 | ret = xenbus_alloc_evtchn(dev, &evtchn); | |
1195 | if (ret) | |
1196 | goto error; | |
1197 | ||
1198 | bedata->irq = bind_evtchn_to_irqhandler(evtchn, | |
1199 | pvcalls_front_event_handler, | |
1200 | 0, "pvcalls-frontend", dev); | |
1201 | if (bedata->irq < 0) { | |
1202 | ret = bedata->irq; | |
1203 | goto error; | |
1204 | } | |
1205 | ||
1206 | ret = gnttab_alloc_grant_references(1, &gref_head); | |
1207 | if (ret < 0) | |
1208 | goto error; | |
95110ac8 CIK |
1209 | ret = gnttab_claim_grant_reference(&gref_head); |
1210 | if (ret < 0) | |
21968190 | 1211 | goto error; |
95110ac8 | 1212 | bedata->ref = ret; |
21968190 SS |
1213 | gnttab_grant_foreign_access_ref(bedata->ref, dev->otherend_id, |
1214 | virt_to_gfn((void *)sring), 0); | |
1215 | ||
1216 | again: | |
1217 | ret = xenbus_transaction_start(&xbt); | |
1218 | if (ret) { | |
1219 | xenbus_dev_fatal(dev, ret, "starting transaction"); | |
1220 | goto error; | |
1221 | } | |
1222 | ret = xenbus_printf(xbt, dev->nodename, "version", "%u", 1); | |
1223 | if (ret) | |
1224 | goto error_xenbus; | |
1225 | ret = xenbus_printf(xbt, dev->nodename, "ring-ref", "%d", bedata->ref); | |
1226 | if (ret) | |
1227 | goto error_xenbus; | |
1228 | ret = xenbus_printf(xbt, dev->nodename, "port", "%u", | |
1229 | evtchn); | |
1230 | if (ret) | |
1231 | goto error_xenbus; | |
1232 | ret = xenbus_transaction_end(xbt, 0); | |
1233 | if (ret) { | |
1234 | if (ret == -EAGAIN) | |
1235 | goto again; | |
1236 | xenbus_dev_fatal(dev, ret, "completing transaction"); | |
1237 | goto error; | |
1238 | } | |
1239 | xenbus_switch_state(dev, XenbusStateInitialised); | |
1240 | ||
416efba0 | 1241 | return 0; |
21968190 SS |
1242 | |
1243 | error_xenbus: | |
1244 | xenbus_transaction_end(xbt, 1); | |
1245 | xenbus_dev_fatal(dev, ret, "writing xenstore"); | |
1246 | error: | |
1247 | pvcalls_front_remove(dev); | |
1248 | return ret; | |
416efba0 SS |
1249 | } |
1250 | ||
1251 | static void pvcalls_front_changed(struct xenbus_device *dev, | |
1252 | enum xenbus_state backend_state) | |
1253 | { | |
21968190 SS |
1254 | switch (backend_state) { |
1255 | case XenbusStateReconfiguring: | |
1256 | case XenbusStateReconfigured: | |
1257 | case XenbusStateInitialising: | |
1258 | case XenbusStateInitialised: | |
1259 | case XenbusStateUnknown: | |
1260 | break; | |
1261 | ||
1262 | case XenbusStateInitWait: | |
1263 | break; | |
1264 | ||
1265 | case XenbusStateConnected: | |
1266 | xenbus_switch_state(dev, XenbusStateConnected); | |
1267 | break; | |
1268 | ||
1269 | case XenbusStateClosed: | |
1270 | if (dev->state == XenbusStateClosed) | |
1271 | break; | |
3d8765d4 | 1272 | /* Missed the backend's CLOSING state */ |
df561f66 | 1273 | fallthrough; |
21968190 SS |
1274 | case XenbusStateClosing: |
1275 | xenbus_frontend_closed(dev); | |
1276 | break; | |
1277 | } | |
416efba0 SS |
1278 | } |
1279 | ||
1280 | static struct xenbus_driver pvcalls_front_driver = { | |
1281 | .ids = pvcalls_front_ids, | |
1282 | .probe = pvcalls_front_probe, | |
1283 | .remove = pvcalls_front_remove, | |
1284 | .otherend_changed = pvcalls_front_changed, | |
03e143b2 | 1285 | .not_essential = true, |
416efba0 SS |
1286 | }; |
1287 | ||
1288 | static int __init pvcalls_frontend_init(void) | |
1289 | { | |
1290 | if (!xen_domain()) | |
1291 | return -ENODEV; | |
1292 | ||
1293 | pr_info("Initialising Xen pvcalls frontend driver\n"); | |
1294 | ||
1295 | return xenbus_register_frontend(&pvcalls_front_driver); | |
1296 | } | |
1297 | ||
1298 | module_init(pvcalls_frontend_init); | |
24e7f84d BO |
1299 | |
1300 | MODULE_DESCRIPTION("Xen PV Calls frontend driver"); | |
1301 | MODULE_AUTHOR("Stefano Stabellini <sstabellini@kernel.org>"); | |
1302 | MODULE_LICENSE("GPL"); |