Commit | Line | Data |
---|---|---|
7a338472 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
0ea9e1d3 AH |
2 | /* |
3 | * virtio transport for vsock | |
4 | * | |
5 | * Copyright (C) 2013-2015 Red Hat, Inc. | |
6 | * Author: Asias He <asias@redhat.com> | |
7 | * Stefan Hajnoczi <stefanha@redhat.com> | |
8 | * | |
9 | * Some of the code is take from Gerd Hoffmann <kraxel@redhat.com>'s | |
10 | * early virtio-vsock proof-of-concept bits. | |
0ea9e1d3 AH |
11 | */ |
12 | #include <linux/spinlock.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/list.h> | |
15 | #include <linux/atomic.h> | |
16 | #include <linux/virtio.h> | |
17 | #include <linux/virtio_ids.h> | |
18 | #include <linux/virtio_config.h> | |
19 | #include <linux/virtio_vsock.h> | |
20 | #include <net/sock.h> | |
21 | #include <linux/mutex.h> | |
22 | #include <net/af_vsock.h> | |
23 | ||
24 | static struct workqueue_struct *virtio_vsock_workqueue; | |
25 | static struct virtio_vsock *the_virtio_vsock; | |
26 | static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */ | |
27 | ||
28 | struct virtio_vsock { | |
29 | struct virtio_device *vdev; | |
30 | struct virtqueue *vqs[VSOCK_VQ_MAX]; | |
31 | ||
32 | /* Virtqueue processing is deferred to a workqueue */ | |
33 | struct work_struct tx_work; | |
34 | struct work_struct rx_work; | |
35 | struct work_struct event_work; | |
36 | ||
37 | /* The following fields are protected by tx_lock. vqs[VSOCK_VQ_TX] | |
38 | * must be accessed with tx_lock held. | |
39 | */ | |
40 | struct mutex tx_lock; | |
b917507e | 41 | bool tx_run; |
0ea9e1d3 AH |
42 | |
43 | struct work_struct send_pkt_work; | |
44 | spinlock_t send_pkt_list_lock; | |
45 | struct list_head send_pkt_list; | |
46 | ||
b9116823 SH |
47 | struct work_struct loopback_work; |
48 | spinlock_t loopback_list_lock; /* protects loopback_list */ | |
49 | struct list_head loopback_list; | |
50 | ||
0ea9e1d3 AH |
51 | atomic_t queued_replies; |
52 | ||
53 | /* The following fields are protected by rx_lock. vqs[VSOCK_VQ_RX] | |
54 | * must be accessed with rx_lock held. | |
55 | */ | |
56 | struct mutex rx_lock; | |
b917507e | 57 | bool rx_run; |
0ea9e1d3 AH |
58 | int rx_buf_nr; |
59 | int rx_buf_max_nr; | |
60 | ||
61 | /* The following fields are protected by event_lock. | |
62 | * vqs[VSOCK_VQ_EVENT] must be accessed with event_lock held. | |
63 | */ | |
64 | struct mutex event_lock; | |
b917507e | 65 | bool event_run; |
0ea9e1d3 AH |
66 | struct virtio_vsock_event event_list[8]; |
67 | ||
68 | u32 guest_cid; | |
69 | }; | |
70 | ||
0ea9e1d3 AH |
71 | static u32 virtio_transport_get_local_cid(void) |
72 | { | |
0deab087 SG |
73 | struct virtio_vsock *vsock; |
74 | u32 ret; | |
0ea9e1d3 | 75 | |
0deab087 SG |
76 | rcu_read_lock(); |
77 | vsock = rcu_dereference(the_virtio_vsock); | |
78 | if (!vsock) { | |
79 | ret = VMADDR_CID_ANY; | |
80 | goto out_rcu; | |
81 | } | |
22b5c0b6 | 82 | |
0deab087 SG |
83 | ret = vsock->guest_cid; |
84 | out_rcu: | |
85 | rcu_read_unlock(); | |
86 | return ret; | |
0ea9e1d3 AH |
87 | } |
88 | ||
b9116823 SH |
89 | static int virtio_transport_send_pkt_loopback(struct virtio_vsock *vsock, |
90 | struct virtio_vsock_pkt *pkt) | |
91 | { | |
92 | int len = pkt->len; | |
93 | ||
94 | spin_lock_bh(&vsock->loopback_list_lock); | |
95 | list_add_tail(&pkt->list, &vsock->loopback_list); | |
96 | spin_unlock_bh(&vsock->loopback_list_lock); | |
97 | ||
98 | queue_work(virtio_vsock_workqueue, &vsock->loopback_work); | |
99 | ||
100 | return len; | |
101 | } | |
102 | ||
0ea9e1d3 AH |
103 | static void |
104 | virtio_transport_send_pkt_work(struct work_struct *work) | |
105 | { | |
106 | struct virtio_vsock *vsock = | |
107 | container_of(work, struct virtio_vsock, send_pkt_work); | |
108 | struct virtqueue *vq; | |
109 | bool added = false; | |
110 | bool restart_rx = false; | |
111 | ||
112 | mutex_lock(&vsock->tx_lock); | |
113 | ||
b917507e SG |
114 | if (!vsock->tx_run) |
115 | goto out; | |
116 | ||
0ea9e1d3 AH |
117 | vq = vsock->vqs[VSOCK_VQ_TX]; |
118 | ||
0ea9e1d3 AH |
119 | for (;;) { |
120 | struct virtio_vsock_pkt *pkt; | |
121 | struct scatterlist hdr, buf, *sgs[2]; | |
122 | int ret, in_sg = 0, out_sg = 0; | |
123 | bool reply; | |
124 | ||
125 | spin_lock_bh(&vsock->send_pkt_list_lock); | |
126 | if (list_empty(&vsock->send_pkt_list)) { | |
127 | spin_unlock_bh(&vsock->send_pkt_list_lock); | |
0ea9e1d3 AH |
128 | break; |
129 | } | |
130 | ||
131 | pkt = list_first_entry(&vsock->send_pkt_list, | |
132 | struct virtio_vsock_pkt, list); | |
133 | list_del_init(&pkt->list); | |
134 | spin_unlock_bh(&vsock->send_pkt_list_lock); | |
135 | ||
82dfb540 GG |
136 | virtio_transport_deliver_tap_pkt(pkt); |
137 | ||
0ea9e1d3 AH |
138 | reply = pkt->reply; |
139 | ||
140 | sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr)); | |
141 | sgs[out_sg++] = &hdr; | |
142 | if (pkt->buf) { | |
143 | sg_init_one(&buf, pkt->buf, pkt->len); | |
144 | sgs[out_sg++] = &buf; | |
145 | } | |
146 | ||
147 | ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt, GFP_KERNEL); | |
21bc54fc GG |
148 | /* Usually this means that there is no more space available in |
149 | * the vq | |
150 | */ | |
0ea9e1d3 AH |
151 | if (ret < 0) { |
152 | spin_lock_bh(&vsock->send_pkt_list_lock); | |
153 | list_add(&pkt->list, &vsock->send_pkt_list); | |
154 | spin_unlock_bh(&vsock->send_pkt_list_lock); | |
0ea9e1d3 AH |
155 | break; |
156 | } | |
157 | ||
158 | if (reply) { | |
159 | struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX]; | |
160 | int val; | |
161 | ||
162 | val = atomic_dec_return(&vsock->queued_replies); | |
163 | ||
164 | /* Do we now have resources to resume rx processing? */ | |
165 | if (val + 1 == virtqueue_get_vring_size(rx_vq)) | |
166 | restart_rx = true; | |
167 | } | |
168 | ||
169 | added = true; | |
170 | } | |
171 | ||
172 | if (added) | |
173 | virtqueue_kick(vq); | |
174 | ||
b917507e | 175 | out: |
0ea9e1d3 AH |
176 | mutex_unlock(&vsock->tx_lock); |
177 | ||
178 | if (restart_rx) | |
179 | queue_work(virtio_vsock_workqueue, &vsock->rx_work); | |
180 | } | |
181 | ||
182 | static int | |
183 | virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt) | |
184 | { | |
185 | struct virtio_vsock *vsock; | |
186 | int len = pkt->len; | |
187 | ||
0deab087 SG |
188 | rcu_read_lock(); |
189 | vsock = rcu_dereference(the_virtio_vsock); | |
0ea9e1d3 AH |
190 | if (!vsock) { |
191 | virtio_transport_free_pkt(pkt); | |
0deab087 SG |
192 | len = -ENODEV; |
193 | goto out_rcu; | |
0ea9e1d3 AH |
194 | } |
195 | ||
0deab087 SG |
196 | if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid) { |
197 | len = virtio_transport_send_pkt_loopback(vsock, pkt); | |
198 | goto out_rcu; | |
199 | } | |
b9116823 | 200 | |
0ea9e1d3 AH |
201 | if (pkt->reply) |
202 | atomic_inc(&vsock->queued_replies); | |
203 | ||
204 | spin_lock_bh(&vsock->send_pkt_list_lock); | |
205 | list_add_tail(&pkt->list, &vsock->send_pkt_list); | |
206 | spin_unlock_bh(&vsock->send_pkt_list_lock); | |
207 | ||
208 | queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work); | |
0deab087 SG |
209 | |
210 | out_rcu: | |
211 | rcu_read_unlock(); | |
0ea9e1d3 AH |
212 | return len; |
213 | } | |
214 | ||
073b4f2c PT |
215 | static int |
216 | virtio_transport_cancel_pkt(struct vsock_sock *vsk) | |
217 | { | |
218 | struct virtio_vsock *vsock; | |
219 | struct virtio_vsock_pkt *pkt, *n; | |
0deab087 | 220 | int cnt = 0, ret; |
073b4f2c PT |
221 | LIST_HEAD(freeme); |
222 | ||
0deab087 SG |
223 | rcu_read_lock(); |
224 | vsock = rcu_dereference(the_virtio_vsock); | |
073b4f2c | 225 | if (!vsock) { |
0deab087 SG |
226 | ret = -ENODEV; |
227 | goto out_rcu; | |
073b4f2c PT |
228 | } |
229 | ||
230 | spin_lock_bh(&vsock->send_pkt_list_lock); | |
231 | list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) { | |
232 | if (pkt->vsk != vsk) | |
233 | continue; | |
234 | list_move(&pkt->list, &freeme); | |
235 | } | |
236 | spin_unlock_bh(&vsock->send_pkt_list_lock); | |
237 | ||
238 | list_for_each_entry_safe(pkt, n, &freeme, list) { | |
239 | if (pkt->reply) | |
240 | cnt++; | |
241 | list_del(&pkt->list); | |
242 | virtio_transport_free_pkt(pkt); | |
243 | } | |
244 | ||
245 | if (cnt) { | |
246 | struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX]; | |
247 | int new_cnt; | |
248 | ||
249 | new_cnt = atomic_sub_return(cnt, &vsock->queued_replies); | |
250 | if (new_cnt + cnt >= virtqueue_get_vring_size(rx_vq) && | |
251 | new_cnt < virtqueue_get_vring_size(rx_vq)) | |
252 | queue_work(virtio_vsock_workqueue, &vsock->rx_work); | |
253 | } | |
254 | ||
0deab087 SG |
255 | ret = 0; |
256 | ||
257 | out_rcu: | |
258 | rcu_read_unlock(); | |
259 | return ret; | |
073b4f2c PT |
260 | } |
261 | ||
0ea9e1d3 AH |
262 | static void virtio_vsock_rx_fill(struct virtio_vsock *vsock) |
263 | { | |
264 | int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE; | |
265 | struct virtio_vsock_pkt *pkt; | |
266 | struct scatterlist hdr, buf, *sgs[2]; | |
267 | struct virtqueue *vq; | |
268 | int ret; | |
269 | ||
270 | vq = vsock->vqs[VSOCK_VQ_RX]; | |
271 | ||
272 | do { | |
273 | pkt = kzalloc(sizeof(*pkt), GFP_KERNEL); | |
274 | if (!pkt) | |
275 | break; | |
276 | ||
277 | pkt->buf = kmalloc(buf_len, GFP_KERNEL); | |
278 | if (!pkt->buf) { | |
279 | virtio_transport_free_pkt(pkt); | |
280 | break; | |
281 | } | |
282 | ||
473c7391 | 283 | pkt->buf_len = buf_len; |
0ea9e1d3 AH |
284 | pkt->len = buf_len; |
285 | ||
286 | sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr)); | |
287 | sgs[0] = &hdr; | |
288 | ||
289 | sg_init_one(&buf, pkt->buf, buf_len); | |
290 | sgs[1] = &buf; | |
291 | ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL); | |
292 | if (ret) { | |
293 | virtio_transport_free_pkt(pkt); | |
294 | break; | |
295 | } | |
296 | vsock->rx_buf_nr++; | |
297 | } while (vq->num_free); | |
298 | if (vsock->rx_buf_nr > vsock->rx_buf_max_nr) | |
299 | vsock->rx_buf_max_nr = vsock->rx_buf_nr; | |
300 | virtqueue_kick(vq); | |
301 | } | |
302 | ||
303 | static void virtio_transport_tx_work(struct work_struct *work) | |
304 | { | |
305 | struct virtio_vsock *vsock = | |
306 | container_of(work, struct virtio_vsock, tx_work); | |
307 | struct virtqueue *vq; | |
308 | bool added = false; | |
309 | ||
310 | vq = vsock->vqs[VSOCK_VQ_TX]; | |
311 | mutex_lock(&vsock->tx_lock); | |
b917507e SG |
312 | |
313 | if (!vsock->tx_run) | |
314 | goto out; | |
315 | ||
0ea9e1d3 AH |
316 | do { |
317 | struct virtio_vsock_pkt *pkt; | |
318 | unsigned int len; | |
319 | ||
320 | virtqueue_disable_cb(vq); | |
321 | while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) { | |
322 | virtio_transport_free_pkt(pkt); | |
323 | added = true; | |
324 | } | |
325 | } while (!virtqueue_enable_cb(vq)); | |
b917507e SG |
326 | |
327 | out: | |
0ea9e1d3 AH |
328 | mutex_unlock(&vsock->tx_lock); |
329 | ||
330 | if (added) | |
331 | queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work); | |
332 | } | |
333 | ||
334 | /* Is there space left for replies to rx packets? */ | |
335 | static bool virtio_transport_more_replies(struct virtio_vsock *vsock) | |
336 | { | |
337 | struct virtqueue *vq = vsock->vqs[VSOCK_VQ_RX]; | |
338 | int val; | |
339 | ||
340 | smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */ | |
341 | val = atomic_read(&vsock->queued_replies); | |
342 | ||
343 | return val < virtqueue_get_vring_size(vq); | |
344 | } | |
345 | ||
0ea9e1d3 AH |
346 | /* event_lock must be held */ |
347 | static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock, | |
348 | struct virtio_vsock_event *event) | |
349 | { | |
350 | struct scatterlist sg; | |
351 | struct virtqueue *vq; | |
352 | ||
353 | vq = vsock->vqs[VSOCK_VQ_EVENT]; | |
354 | ||
355 | sg_init_one(&sg, event, sizeof(*event)); | |
356 | ||
357 | return virtqueue_add_inbuf(vq, &sg, 1, event, GFP_KERNEL); | |
358 | } | |
359 | ||
360 | /* event_lock must be held */ | |
361 | static void virtio_vsock_event_fill(struct virtio_vsock *vsock) | |
362 | { | |
363 | size_t i; | |
364 | ||
365 | for (i = 0; i < ARRAY_SIZE(vsock->event_list); i++) { | |
366 | struct virtio_vsock_event *event = &vsock->event_list[i]; | |
367 | ||
368 | virtio_vsock_event_fill_one(vsock, event); | |
369 | } | |
370 | ||
371 | virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]); | |
372 | } | |
373 | ||
374 | static void virtio_vsock_reset_sock(struct sock *sk) | |
375 | { | |
376 | lock_sock(sk); | |
3b4477d2 | 377 | sk->sk_state = TCP_CLOSE; |
0ea9e1d3 AH |
378 | sk->sk_err = ECONNRESET; |
379 | sk->sk_error_report(sk); | |
380 | release_sock(sk); | |
381 | } | |
382 | ||
383 | static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock) | |
384 | { | |
385 | struct virtio_device *vdev = vsock->vdev; | |
6c7efafd | 386 | __le64 guest_cid; |
0ea9e1d3 AH |
387 | |
388 | vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid), | |
389 | &guest_cid, sizeof(guest_cid)); | |
390 | vsock->guest_cid = le64_to_cpu(guest_cid); | |
391 | } | |
392 | ||
393 | /* event_lock must be held */ | |
394 | static void virtio_vsock_event_handle(struct virtio_vsock *vsock, | |
395 | struct virtio_vsock_event *event) | |
396 | { | |
397 | switch (le32_to_cpu(event->id)) { | |
398 | case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET: | |
399 | virtio_vsock_update_guest_cid(vsock); | |
400 | vsock_for_each_connected_socket(virtio_vsock_reset_sock); | |
401 | break; | |
402 | } | |
403 | } | |
404 | ||
405 | static void virtio_transport_event_work(struct work_struct *work) | |
406 | { | |
407 | struct virtio_vsock *vsock = | |
408 | container_of(work, struct virtio_vsock, event_work); | |
409 | struct virtqueue *vq; | |
410 | ||
411 | vq = vsock->vqs[VSOCK_VQ_EVENT]; | |
412 | ||
413 | mutex_lock(&vsock->event_lock); | |
414 | ||
b917507e SG |
415 | if (!vsock->event_run) |
416 | goto out; | |
417 | ||
0ea9e1d3 AH |
418 | do { |
419 | struct virtio_vsock_event *event; | |
420 | unsigned int len; | |
421 | ||
422 | virtqueue_disable_cb(vq); | |
423 | while ((event = virtqueue_get_buf(vq, &len)) != NULL) { | |
424 | if (len == sizeof(*event)) | |
425 | virtio_vsock_event_handle(vsock, event); | |
426 | ||
427 | virtio_vsock_event_fill_one(vsock, event); | |
428 | } | |
429 | } while (!virtqueue_enable_cb(vq)); | |
430 | ||
431 | virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]); | |
b917507e | 432 | out: |
0ea9e1d3 AH |
433 | mutex_unlock(&vsock->event_lock); |
434 | } | |
435 | ||
436 | static void virtio_vsock_event_done(struct virtqueue *vq) | |
437 | { | |
438 | struct virtio_vsock *vsock = vq->vdev->priv; | |
439 | ||
440 | if (!vsock) | |
441 | return; | |
442 | queue_work(virtio_vsock_workqueue, &vsock->event_work); | |
443 | } | |
444 | ||
445 | static void virtio_vsock_tx_done(struct virtqueue *vq) | |
446 | { | |
447 | struct virtio_vsock *vsock = vq->vdev->priv; | |
448 | ||
449 | if (!vsock) | |
450 | return; | |
451 | queue_work(virtio_vsock_workqueue, &vsock->tx_work); | |
452 | } | |
453 | ||
454 | static void virtio_vsock_rx_done(struct virtqueue *vq) | |
455 | { | |
456 | struct virtio_vsock *vsock = vq->vdev->priv; | |
457 | ||
458 | if (!vsock) | |
459 | return; | |
460 | queue_work(virtio_vsock_workqueue, &vsock->rx_work); | |
461 | } | |
462 | ||
463 | static struct virtio_transport virtio_transport = { | |
464 | .transport = { | |
465 | .get_local_cid = virtio_transport_get_local_cid, | |
466 | ||
467 | .init = virtio_transport_do_socket_init, | |
468 | .destruct = virtio_transport_destruct, | |
469 | .release = virtio_transport_release, | |
470 | .connect = virtio_transport_connect, | |
471 | .shutdown = virtio_transport_shutdown, | |
073b4f2c | 472 | .cancel_pkt = virtio_transport_cancel_pkt, |
0ea9e1d3 AH |
473 | |
474 | .dgram_bind = virtio_transport_dgram_bind, | |
475 | .dgram_dequeue = virtio_transport_dgram_dequeue, | |
476 | .dgram_enqueue = virtio_transport_dgram_enqueue, | |
477 | .dgram_allow = virtio_transport_dgram_allow, | |
478 | ||
479 | .stream_dequeue = virtio_transport_stream_dequeue, | |
480 | .stream_enqueue = virtio_transport_stream_enqueue, | |
481 | .stream_has_data = virtio_transport_stream_has_data, | |
482 | .stream_has_space = virtio_transport_stream_has_space, | |
483 | .stream_rcvhiwat = virtio_transport_stream_rcvhiwat, | |
484 | .stream_is_active = virtio_transport_stream_is_active, | |
485 | .stream_allow = virtio_transport_stream_allow, | |
486 | ||
487 | .notify_poll_in = virtio_transport_notify_poll_in, | |
488 | .notify_poll_out = virtio_transport_notify_poll_out, | |
489 | .notify_recv_init = virtio_transport_notify_recv_init, | |
490 | .notify_recv_pre_block = virtio_transport_notify_recv_pre_block, | |
491 | .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue, | |
492 | .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue, | |
493 | .notify_send_init = virtio_transport_notify_send_init, | |
494 | .notify_send_pre_block = virtio_transport_notify_send_pre_block, | |
495 | .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, | |
496 | .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, | |
b9f2b0ff | 497 | .notify_buffer_size = virtio_transport_notify_buffer_size, |
0ea9e1d3 AH |
498 | }, |
499 | ||
500 | .send_pkt = virtio_transport_send_pkt, | |
501 | }; | |
502 | ||
4c7246dc SG |
503 | static void virtio_transport_loopback_work(struct work_struct *work) |
504 | { | |
505 | struct virtio_vsock *vsock = | |
506 | container_of(work, struct virtio_vsock, loopback_work); | |
507 | LIST_HEAD(pkts); | |
508 | ||
509 | spin_lock_bh(&vsock->loopback_list_lock); | |
510 | list_splice_init(&vsock->loopback_list, &pkts); | |
511 | spin_unlock_bh(&vsock->loopback_list_lock); | |
512 | ||
513 | mutex_lock(&vsock->rx_lock); | |
514 | ||
515 | if (!vsock->rx_run) | |
516 | goto out; | |
517 | ||
518 | while (!list_empty(&pkts)) { | |
519 | struct virtio_vsock_pkt *pkt; | |
520 | ||
521 | pkt = list_first_entry(&pkts, struct virtio_vsock_pkt, list); | |
522 | list_del_init(&pkt->list); | |
523 | ||
524 | virtio_transport_recv_pkt(&virtio_transport, pkt); | |
525 | } | |
526 | out: | |
527 | mutex_unlock(&vsock->rx_lock); | |
528 | } | |
529 | ||
530 | static void virtio_transport_rx_work(struct work_struct *work) | |
531 | { | |
532 | struct virtio_vsock *vsock = | |
533 | container_of(work, struct virtio_vsock, rx_work); | |
534 | struct virtqueue *vq; | |
535 | ||
536 | vq = vsock->vqs[VSOCK_VQ_RX]; | |
537 | ||
538 | mutex_lock(&vsock->rx_lock); | |
539 | ||
540 | if (!vsock->rx_run) | |
541 | goto out; | |
542 | ||
543 | do { | |
544 | virtqueue_disable_cb(vq); | |
545 | for (;;) { | |
546 | struct virtio_vsock_pkt *pkt; | |
547 | unsigned int len; | |
548 | ||
549 | if (!virtio_transport_more_replies(vsock)) { | |
550 | /* Stop rx until the device processes already | |
551 | * pending replies. Leave rx virtqueue | |
552 | * callbacks disabled. | |
553 | */ | |
554 | goto out; | |
555 | } | |
556 | ||
557 | pkt = virtqueue_get_buf(vq, &len); | |
558 | if (!pkt) { | |
559 | break; | |
560 | } | |
561 | ||
562 | vsock->rx_buf_nr--; | |
563 | ||
564 | /* Drop short/long packets */ | |
565 | if (unlikely(len < sizeof(pkt->hdr) || | |
566 | len > sizeof(pkt->hdr) + pkt->len)) { | |
567 | virtio_transport_free_pkt(pkt); | |
568 | continue; | |
569 | } | |
570 | ||
571 | pkt->len = len - sizeof(pkt->hdr); | |
572 | virtio_transport_deliver_tap_pkt(pkt); | |
573 | virtio_transport_recv_pkt(&virtio_transport, pkt); | |
574 | } | |
575 | } while (!virtqueue_enable_cb(vq)); | |
576 | ||
577 | out: | |
578 | if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2) | |
579 | virtio_vsock_rx_fill(vsock); | |
580 | mutex_unlock(&vsock->rx_lock); | |
581 | } | |
582 | ||
0ea9e1d3 AH |
583 | static int virtio_vsock_probe(struct virtio_device *vdev) |
584 | { | |
585 | vq_callback_t *callbacks[] = { | |
586 | virtio_vsock_rx_done, | |
587 | virtio_vsock_tx_done, | |
588 | virtio_vsock_event_done, | |
589 | }; | |
590 | static const char * const names[] = { | |
591 | "rx", | |
592 | "tx", | |
593 | "event", | |
594 | }; | |
595 | struct virtio_vsock *vsock = NULL; | |
596 | int ret; | |
597 | ||
598 | ret = mutex_lock_interruptible(&the_virtio_vsock_mutex); | |
599 | if (ret) | |
600 | return ret; | |
601 | ||
602 | /* Only one virtio-vsock device per guest is supported */ | |
0deab087 SG |
603 | if (rcu_dereference_protected(the_virtio_vsock, |
604 | lockdep_is_held(&the_virtio_vsock_mutex))) { | |
0ea9e1d3 AH |
605 | ret = -EBUSY; |
606 | goto out; | |
607 | } | |
608 | ||
609 | vsock = kzalloc(sizeof(*vsock), GFP_KERNEL); | |
610 | if (!vsock) { | |
611 | ret = -ENOMEM; | |
612 | goto out; | |
613 | } | |
614 | ||
615 | vsock->vdev = vdev; | |
616 | ||
9b2bbdb2 MT |
617 | ret = virtio_find_vqs(vsock->vdev, VSOCK_VQ_MAX, |
618 | vsock->vqs, callbacks, names, | |
619 | NULL); | |
0ea9e1d3 AH |
620 | if (ret < 0) |
621 | goto out; | |
622 | ||
623 | virtio_vsock_update_guest_cid(vsock); | |
624 | ||
0ea9e1d3 AH |
625 | vsock->rx_buf_nr = 0; |
626 | vsock->rx_buf_max_nr = 0; | |
627 | atomic_set(&vsock->queued_replies, 0); | |
628 | ||
0ea9e1d3 AH |
629 | mutex_init(&vsock->tx_lock); |
630 | mutex_init(&vsock->rx_lock); | |
631 | mutex_init(&vsock->event_lock); | |
632 | spin_lock_init(&vsock->send_pkt_list_lock); | |
633 | INIT_LIST_HEAD(&vsock->send_pkt_list); | |
b9116823 SH |
634 | spin_lock_init(&vsock->loopback_list_lock); |
635 | INIT_LIST_HEAD(&vsock->loopback_list); | |
0ea9e1d3 AH |
636 | INIT_WORK(&vsock->rx_work, virtio_transport_rx_work); |
637 | INIT_WORK(&vsock->tx_work, virtio_transport_tx_work); | |
638 | INIT_WORK(&vsock->event_work, virtio_transport_event_work); | |
639 | INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work); | |
b9116823 | 640 | INIT_WORK(&vsock->loopback_work, virtio_transport_loopback_work); |
0ea9e1d3 | 641 | |
b917507e SG |
642 | mutex_lock(&vsock->tx_lock); |
643 | vsock->tx_run = true; | |
644 | mutex_unlock(&vsock->tx_lock); | |
645 | ||
0ea9e1d3 AH |
646 | mutex_lock(&vsock->rx_lock); |
647 | virtio_vsock_rx_fill(vsock); | |
b917507e | 648 | vsock->rx_run = true; |
0ea9e1d3 AH |
649 | mutex_unlock(&vsock->rx_lock); |
650 | ||
651 | mutex_lock(&vsock->event_lock); | |
652 | virtio_vsock_event_fill(vsock); | |
b917507e | 653 | vsock->event_run = true; |
0ea9e1d3 AH |
654 | mutex_unlock(&vsock->event_lock); |
655 | ||
0deab087 SG |
656 | vdev->priv = vsock; |
657 | rcu_assign_pointer(the_virtio_vsock, vsock); | |
658 | ||
0ea9e1d3 AH |
659 | mutex_unlock(&the_virtio_vsock_mutex); |
660 | return 0; | |
661 | ||
0ea9e1d3 AH |
662 | out: |
663 | kfree(vsock); | |
664 | mutex_unlock(&the_virtio_vsock_mutex); | |
665 | return ret; | |
666 | } | |
667 | ||
668 | static void virtio_vsock_remove(struct virtio_device *vdev) | |
669 | { | |
670 | struct virtio_vsock *vsock = vdev->priv; | |
671 | struct virtio_vsock_pkt *pkt; | |
672 | ||
0deab087 SG |
673 | mutex_lock(&the_virtio_vsock_mutex); |
674 | ||
675 | vdev->priv = NULL; | |
676 | rcu_assign_pointer(the_virtio_vsock, NULL); | |
677 | synchronize_rcu(); | |
678 | ||
85965487 SG |
679 | /* Reset all connected sockets when the device disappear */ |
680 | vsock_for_each_connected_socket(virtio_vsock_reset_sock); | |
681 | ||
b917507e SG |
682 | /* Stop all work handlers to make sure no one is accessing the device, |
683 | * so we can safely call vdev->config->reset(). | |
684 | */ | |
685 | mutex_lock(&vsock->rx_lock); | |
686 | vsock->rx_run = false; | |
687 | mutex_unlock(&vsock->rx_lock); | |
688 | ||
689 | mutex_lock(&vsock->tx_lock); | |
690 | vsock->tx_run = false; | |
691 | mutex_unlock(&vsock->tx_lock); | |
692 | ||
693 | mutex_lock(&vsock->event_lock); | |
694 | vsock->event_run = false; | |
695 | mutex_unlock(&vsock->event_lock); | |
696 | ||
697 | /* Flush all device writes and interrupts, device will not use any | |
698 | * more buffers. | |
699 | */ | |
0ea9e1d3 AH |
700 | vdev->config->reset(vdev); |
701 | ||
702 | mutex_lock(&vsock->rx_lock); | |
703 | while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX]))) | |
704 | virtio_transport_free_pkt(pkt); | |
705 | mutex_unlock(&vsock->rx_lock); | |
706 | ||
707 | mutex_lock(&vsock->tx_lock); | |
708 | while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX]))) | |
709 | virtio_transport_free_pkt(pkt); | |
710 | mutex_unlock(&vsock->tx_lock); | |
711 | ||
712 | spin_lock_bh(&vsock->send_pkt_list_lock); | |
713 | while (!list_empty(&vsock->send_pkt_list)) { | |
714 | pkt = list_first_entry(&vsock->send_pkt_list, | |
715 | struct virtio_vsock_pkt, list); | |
716 | list_del(&pkt->list); | |
717 | virtio_transport_free_pkt(pkt); | |
718 | } | |
719 | spin_unlock_bh(&vsock->send_pkt_list_lock); | |
720 | ||
b9116823 SH |
721 | spin_lock_bh(&vsock->loopback_list_lock); |
722 | while (!list_empty(&vsock->loopback_list)) { | |
723 | pkt = list_first_entry(&vsock->loopback_list, | |
724 | struct virtio_vsock_pkt, list); | |
725 | list_del(&pkt->list); | |
726 | virtio_transport_free_pkt(pkt); | |
727 | } | |
728 | spin_unlock_bh(&vsock->loopback_list_lock); | |
729 | ||
b917507e | 730 | /* Delete virtqueues and flush outstanding callbacks if any */ |
0ea9e1d3 AH |
731 | vdev->config->del_vqs(vdev); |
732 | ||
e226121f SG |
733 | /* Other works can be queued before 'config->del_vqs()', so we flush |
734 | * all works before to free the vsock object to avoid use after free. | |
735 | */ | |
736 | flush_work(&vsock->loopback_work); | |
737 | flush_work(&vsock->rx_work); | |
738 | flush_work(&vsock->tx_work); | |
739 | flush_work(&vsock->event_work); | |
740 | flush_work(&vsock->send_pkt_work); | |
741 | ||
0deab087 SG |
742 | mutex_unlock(&the_virtio_vsock_mutex); |
743 | ||
0ea9e1d3 AH |
744 | kfree(vsock); |
745 | } | |
746 | ||
747 | static struct virtio_device_id id_table[] = { | |
748 | { VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID }, | |
749 | { 0 }, | |
750 | }; | |
751 | ||
752 | static unsigned int features[] = { | |
753 | }; | |
754 | ||
755 | static struct virtio_driver virtio_vsock_driver = { | |
756 | .feature_table = features, | |
757 | .feature_table_size = ARRAY_SIZE(features), | |
758 | .driver.name = KBUILD_MODNAME, | |
759 | .driver.owner = THIS_MODULE, | |
760 | .id_table = id_table, | |
761 | .probe = virtio_vsock_probe, | |
762 | .remove = virtio_vsock_remove, | |
763 | }; | |
764 | ||
765 | static int __init virtio_vsock_init(void) | |
766 | { | |
767 | int ret; | |
768 | ||
769 | virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0); | |
770 | if (!virtio_vsock_workqueue) | |
771 | return -ENOMEM; | |
22b5c0b6 | 772 | |
ba95e5df | 773 | ret = vsock_core_init(&virtio_transport.transport); |
0ea9e1d3 | 774 | if (ret) |
22b5c0b6 SG |
775 | goto out_wq; |
776 | ||
ba95e5df | 777 | ret = register_virtio_driver(&virtio_vsock_driver); |
22b5c0b6 | 778 | if (ret) |
ba95e5df | 779 | goto out_vci; |
22b5c0b6 SG |
780 | |
781 | return 0; | |
782 | ||
ba95e5df JM |
783 | out_vci: |
784 | vsock_core_exit(); | |
22b5c0b6 SG |
785 | out_wq: |
786 | destroy_workqueue(virtio_vsock_workqueue); | |
0ea9e1d3 AH |
787 | return ret; |
788 | } | |
789 | ||
790 | static void __exit virtio_vsock_exit(void) | |
791 | { | |
792 | unregister_virtio_driver(&virtio_vsock_driver); | |
ba95e5df | 793 | vsock_core_exit(); |
0ea9e1d3 AH |
794 | destroy_workqueue(virtio_vsock_workqueue); |
795 | } | |
796 | ||
797 | module_init(virtio_vsock_init); | |
798 | module_exit(virtio_vsock_exit); | |
799 | MODULE_LICENSE("GPL v2"); | |
800 | MODULE_AUTHOR("Asias He"); | |
801 | MODULE_DESCRIPTION("virtio transport for vsock"); | |
802 | MODULE_DEVICE_TABLE(virtio, id_table); |