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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; | |
f961134a | 25 | static struct virtio_vsock __rcu *the_virtio_vsock; |
0ea9e1d3 AH |
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 | ||
47 | atomic_t queued_replies; | |
48 | ||
49 | /* The following fields are protected by rx_lock. vqs[VSOCK_VQ_RX] | |
50 | * must be accessed with rx_lock held. | |
51 | */ | |
52 | struct mutex rx_lock; | |
b917507e | 53 | bool rx_run; |
0ea9e1d3 AH |
54 | int rx_buf_nr; |
55 | int rx_buf_max_nr; | |
56 | ||
57 | /* The following fields are protected by event_lock. | |
58 | * vqs[VSOCK_VQ_EVENT] must be accessed with event_lock held. | |
59 | */ | |
60 | struct mutex event_lock; | |
b917507e | 61 | bool event_run; |
0ea9e1d3 AH |
62 | struct virtio_vsock_event event_list[8]; |
63 | ||
64 | u32 guest_cid; | |
53efbba1 | 65 | bool seqpacket_allow; |
0ea9e1d3 AH |
66 | }; |
67 | ||
0ea9e1d3 AH |
68 | static u32 virtio_transport_get_local_cid(void) |
69 | { | |
0deab087 SG |
70 | struct virtio_vsock *vsock; |
71 | u32 ret; | |
0ea9e1d3 | 72 | |
0deab087 SG |
73 | rcu_read_lock(); |
74 | vsock = rcu_dereference(the_virtio_vsock); | |
75 | if (!vsock) { | |
76 | ret = VMADDR_CID_ANY; | |
77 | goto out_rcu; | |
78 | } | |
22b5c0b6 | 79 | |
0deab087 SG |
80 | ret = vsock->guest_cid; |
81 | out_rcu: | |
82 | rcu_read_unlock(); | |
83 | return ret; | |
0ea9e1d3 AH |
84 | } |
85 | ||
86 | static void | |
87 | virtio_transport_send_pkt_work(struct work_struct *work) | |
88 | { | |
89 | struct virtio_vsock *vsock = | |
90 | container_of(work, struct virtio_vsock, send_pkt_work); | |
91 | struct virtqueue *vq; | |
92 | bool added = false; | |
93 | bool restart_rx = false; | |
94 | ||
95 | mutex_lock(&vsock->tx_lock); | |
96 | ||
b917507e SG |
97 | if (!vsock->tx_run) |
98 | goto out; | |
99 | ||
0ea9e1d3 AH |
100 | vq = vsock->vqs[VSOCK_VQ_TX]; |
101 | ||
0ea9e1d3 AH |
102 | for (;;) { |
103 | struct virtio_vsock_pkt *pkt; | |
104 | struct scatterlist hdr, buf, *sgs[2]; | |
105 | int ret, in_sg = 0, out_sg = 0; | |
106 | bool reply; | |
107 | ||
108 | spin_lock_bh(&vsock->send_pkt_list_lock); | |
109 | if (list_empty(&vsock->send_pkt_list)) { | |
110 | spin_unlock_bh(&vsock->send_pkt_list_lock); | |
0ea9e1d3 AH |
111 | break; |
112 | } | |
113 | ||
114 | pkt = list_first_entry(&vsock->send_pkt_list, | |
115 | struct virtio_vsock_pkt, list); | |
116 | list_del_init(&pkt->list); | |
117 | spin_unlock_bh(&vsock->send_pkt_list_lock); | |
118 | ||
82dfb540 GG |
119 | virtio_transport_deliver_tap_pkt(pkt); |
120 | ||
0ea9e1d3 AH |
121 | reply = pkt->reply; |
122 | ||
123 | sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr)); | |
124 | sgs[out_sg++] = &hdr; | |
125 | if (pkt->buf) { | |
126 | sg_init_one(&buf, pkt->buf, pkt->len); | |
127 | sgs[out_sg++] = &buf; | |
128 | } | |
129 | ||
130 | ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt, GFP_KERNEL); | |
21bc54fc GG |
131 | /* Usually this means that there is no more space available in |
132 | * the vq | |
133 | */ | |
0ea9e1d3 AH |
134 | if (ret < 0) { |
135 | spin_lock_bh(&vsock->send_pkt_list_lock); | |
136 | list_add(&pkt->list, &vsock->send_pkt_list); | |
137 | spin_unlock_bh(&vsock->send_pkt_list_lock); | |
0ea9e1d3 AH |
138 | break; |
139 | } | |
140 | ||
141 | if (reply) { | |
142 | struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX]; | |
143 | int val; | |
144 | ||
145 | val = atomic_dec_return(&vsock->queued_replies); | |
146 | ||
147 | /* Do we now have resources to resume rx processing? */ | |
148 | if (val + 1 == virtqueue_get_vring_size(rx_vq)) | |
149 | restart_rx = true; | |
150 | } | |
151 | ||
152 | added = true; | |
153 | } | |
154 | ||
155 | if (added) | |
156 | virtqueue_kick(vq); | |
157 | ||
b917507e | 158 | out: |
0ea9e1d3 AH |
159 | mutex_unlock(&vsock->tx_lock); |
160 | ||
161 | if (restart_rx) | |
162 | queue_work(virtio_vsock_workqueue, &vsock->rx_work); | |
163 | } | |
164 | ||
165 | static int | |
166 | virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt) | |
167 | { | |
168 | struct virtio_vsock *vsock; | |
169 | int len = pkt->len; | |
170 | ||
0deab087 SG |
171 | rcu_read_lock(); |
172 | vsock = rcu_dereference(the_virtio_vsock); | |
0ea9e1d3 AH |
173 | if (!vsock) { |
174 | virtio_transport_free_pkt(pkt); | |
0deab087 SG |
175 | len = -ENODEV; |
176 | goto out_rcu; | |
0ea9e1d3 AH |
177 | } |
178 | ||
0deab087 | 179 | if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid) { |
bf5432b1 SG |
180 | virtio_transport_free_pkt(pkt); |
181 | len = -ENODEV; | |
0deab087 SG |
182 | goto out_rcu; |
183 | } | |
b9116823 | 184 | |
0ea9e1d3 AH |
185 | if (pkt->reply) |
186 | atomic_inc(&vsock->queued_replies); | |
187 | ||
188 | spin_lock_bh(&vsock->send_pkt_list_lock); | |
189 | list_add_tail(&pkt->list, &vsock->send_pkt_list); | |
190 | spin_unlock_bh(&vsock->send_pkt_list_lock); | |
191 | ||
192 | queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work); | |
0deab087 SG |
193 | |
194 | out_rcu: | |
195 | rcu_read_unlock(); | |
0ea9e1d3 AH |
196 | return len; |
197 | } | |
198 | ||
073b4f2c PT |
199 | static int |
200 | virtio_transport_cancel_pkt(struct vsock_sock *vsk) | |
201 | { | |
202 | struct virtio_vsock *vsock; | |
203 | struct virtio_vsock_pkt *pkt, *n; | |
0deab087 | 204 | int cnt = 0, ret; |
073b4f2c PT |
205 | LIST_HEAD(freeme); |
206 | ||
0deab087 SG |
207 | rcu_read_lock(); |
208 | vsock = rcu_dereference(the_virtio_vsock); | |
073b4f2c | 209 | if (!vsock) { |
0deab087 SG |
210 | ret = -ENODEV; |
211 | goto out_rcu; | |
073b4f2c PT |
212 | } |
213 | ||
214 | spin_lock_bh(&vsock->send_pkt_list_lock); | |
215 | list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) { | |
216 | if (pkt->vsk != vsk) | |
217 | continue; | |
218 | list_move(&pkt->list, &freeme); | |
219 | } | |
220 | spin_unlock_bh(&vsock->send_pkt_list_lock); | |
221 | ||
222 | list_for_each_entry_safe(pkt, n, &freeme, list) { | |
223 | if (pkt->reply) | |
224 | cnt++; | |
225 | list_del(&pkt->list); | |
226 | virtio_transport_free_pkt(pkt); | |
227 | } | |
228 | ||
229 | if (cnt) { | |
230 | struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX]; | |
231 | int new_cnt; | |
232 | ||
233 | new_cnt = atomic_sub_return(cnt, &vsock->queued_replies); | |
234 | if (new_cnt + cnt >= virtqueue_get_vring_size(rx_vq) && | |
235 | new_cnt < virtqueue_get_vring_size(rx_vq)) | |
236 | queue_work(virtio_vsock_workqueue, &vsock->rx_work); | |
237 | } | |
238 | ||
0deab087 SG |
239 | ret = 0; |
240 | ||
241 | out_rcu: | |
242 | rcu_read_unlock(); | |
243 | return ret; | |
073b4f2c PT |
244 | } |
245 | ||
0ea9e1d3 AH |
246 | static void virtio_vsock_rx_fill(struct virtio_vsock *vsock) |
247 | { | |
248 | int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE; | |
249 | struct virtio_vsock_pkt *pkt; | |
250 | struct scatterlist hdr, buf, *sgs[2]; | |
251 | struct virtqueue *vq; | |
252 | int ret; | |
253 | ||
254 | vq = vsock->vqs[VSOCK_VQ_RX]; | |
255 | ||
256 | do { | |
257 | pkt = kzalloc(sizeof(*pkt), GFP_KERNEL); | |
258 | if (!pkt) | |
259 | break; | |
260 | ||
261 | pkt->buf = kmalloc(buf_len, GFP_KERNEL); | |
262 | if (!pkt->buf) { | |
263 | virtio_transport_free_pkt(pkt); | |
264 | break; | |
265 | } | |
266 | ||
473c7391 | 267 | pkt->buf_len = buf_len; |
0ea9e1d3 AH |
268 | pkt->len = buf_len; |
269 | ||
270 | sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr)); | |
271 | sgs[0] = &hdr; | |
272 | ||
273 | sg_init_one(&buf, pkt->buf, buf_len); | |
274 | sgs[1] = &buf; | |
275 | ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL); | |
276 | if (ret) { | |
277 | virtio_transport_free_pkt(pkt); | |
278 | break; | |
279 | } | |
280 | vsock->rx_buf_nr++; | |
281 | } while (vq->num_free); | |
282 | if (vsock->rx_buf_nr > vsock->rx_buf_max_nr) | |
283 | vsock->rx_buf_max_nr = vsock->rx_buf_nr; | |
284 | virtqueue_kick(vq); | |
285 | } | |
286 | ||
287 | static void virtio_transport_tx_work(struct work_struct *work) | |
288 | { | |
289 | struct virtio_vsock *vsock = | |
290 | container_of(work, struct virtio_vsock, tx_work); | |
291 | struct virtqueue *vq; | |
292 | bool added = false; | |
293 | ||
294 | vq = vsock->vqs[VSOCK_VQ_TX]; | |
295 | mutex_lock(&vsock->tx_lock); | |
b917507e SG |
296 | |
297 | if (!vsock->tx_run) | |
298 | goto out; | |
299 | ||
0ea9e1d3 AH |
300 | do { |
301 | struct virtio_vsock_pkt *pkt; | |
302 | unsigned int len; | |
303 | ||
304 | virtqueue_disable_cb(vq); | |
305 | while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) { | |
306 | virtio_transport_free_pkt(pkt); | |
307 | added = true; | |
308 | } | |
309 | } while (!virtqueue_enable_cb(vq)); | |
b917507e SG |
310 | |
311 | out: | |
0ea9e1d3 AH |
312 | mutex_unlock(&vsock->tx_lock); |
313 | ||
314 | if (added) | |
315 | queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work); | |
316 | } | |
317 | ||
318 | /* Is there space left for replies to rx packets? */ | |
319 | static bool virtio_transport_more_replies(struct virtio_vsock *vsock) | |
320 | { | |
321 | struct virtqueue *vq = vsock->vqs[VSOCK_VQ_RX]; | |
322 | int val; | |
323 | ||
324 | smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */ | |
325 | val = atomic_read(&vsock->queued_replies); | |
326 | ||
327 | return val < virtqueue_get_vring_size(vq); | |
328 | } | |
329 | ||
0ea9e1d3 AH |
330 | /* event_lock must be held */ |
331 | static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock, | |
332 | struct virtio_vsock_event *event) | |
333 | { | |
334 | struct scatterlist sg; | |
335 | struct virtqueue *vq; | |
336 | ||
337 | vq = vsock->vqs[VSOCK_VQ_EVENT]; | |
338 | ||
339 | sg_init_one(&sg, event, sizeof(*event)); | |
340 | ||
341 | return virtqueue_add_inbuf(vq, &sg, 1, event, GFP_KERNEL); | |
342 | } | |
343 | ||
344 | /* event_lock must be held */ | |
345 | static void virtio_vsock_event_fill(struct virtio_vsock *vsock) | |
346 | { | |
347 | size_t i; | |
348 | ||
349 | for (i = 0; i < ARRAY_SIZE(vsock->event_list); i++) { | |
350 | struct virtio_vsock_event *event = &vsock->event_list[i]; | |
351 | ||
352 | virtio_vsock_event_fill_one(vsock, event); | |
353 | } | |
354 | ||
355 | virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]); | |
356 | } | |
357 | ||
358 | static void virtio_vsock_reset_sock(struct sock *sk) | |
359 | { | |
49b0b6ff LM |
360 | /* vmci_transport.c doesn't take sk_lock here either. At least we're |
361 | * under vsock_table_lock so the sock cannot disappear while we're | |
362 | * executing. | |
363 | */ | |
364 | ||
3b4477d2 | 365 | sk->sk_state = TCP_CLOSE; |
0ea9e1d3 | 366 | sk->sk_err = ECONNRESET; |
e3ae2365 | 367 | sk_error_report(sk); |
0ea9e1d3 AH |
368 | } |
369 | ||
370 | static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock) | |
371 | { | |
372 | struct virtio_device *vdev = vsock->vdev; | |
6c7efafd | 373 | __le64 guest_cid; |
0ea9e1d3 AH |
374 | |
375 | vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid), | |
376 | &guest_cid, sizeof(guest_cid)); | |
377 | vsock->guest_cid = le64_to_cpu(guest_cid); | |
378 | } | |
379 | ||
380 | /* event_lock must be held */ | |
381 | static void virtio_vsock_event_handle(struct virtio_vsock *vsock, | |
382 | struct virtio_vsock_event *event) | |
383 | { | |
384 | switch (le32_to_cpu(event->id)) { | |
385 | case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET: | |
386 | virtio_vsock_update_guest_cid(vsock); | |
387 | vsock_for_each_connected_socket(virtio_vsock_reset_sock); | |
388 | break; | |
389 | } | |
390 | } | |
391 | ||
392 | static void virtio_transport_event_work(struct work_struct *work) | |
393 | { | |
394 | struct virtio_vsock *vsock = | |
395 | container_of(work, struct virtio_vsock, event_work); | |
396 | struct virtqueue *vq; | |
397 | ||
398 | vq = vsock->vqs[VSOCK_VQ_EVENT]; | |
399 | ||
400 | mutex_lock(&vsock->event_lock); | |
401 | ||
b917507e SG |
402 | if (!vsock->event_run) |
403 | goto out; | |
404 | ||
0ea9e1d3 AH |
405 | do { |
406 | struct virtio_vsock_event *event; | |
407 | unsigned int len; | |
408 | ||
409 | virtqueue_disable_cb(vq); | |
410 | while ((event = virtqueue_get_buf(vq, &len)) != NULL) { | |
411 | if (len == sizeof(*event)) | |
412 | virtio_vsock_event_handle(vsock, event); | |
413 | ||
414 | virtio_vsock_event_fill_one(vsock, event); | |
415 | } | |
416 | } while (!virtqueue_enable_cb(vq)); | |
417 | ||
418 | virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]); | |
b917507e | 419 | out: |
0ea9e1d3 AH |
420 | mutex_unlock(&vsock->event_lock); |
421 | } | |
422 | ||
423 | static void virtio_vsock_event_done(struct virtqueue *vq) | |
424 | { | |
425 | struct virtio_vsock *vsock = vq->vdev->priv; | |
426 | ||
427 | if (!vsock) | |
428 | return; | |
429 | queue_work(virtio_vsock_workqueue, &vsock->event_work); | |
430 | } | |
431 | ||
432 | static void virtio_vsock_tx_done(struct virtqueue *vq) | |
433 | { | |
434 | struct virtio_vsock *vsock = vq->vdev->priv; | |
435 | ||
436 | if (!vsock) | |
437 | return; | |
438 | queue_work(virtio_vsock_workqueue, &vsock->tx_work); | |
439 | } | |
440 | ||
441 | static void virtio_vsock_rx_done(struct virtqueue *vq) | |
442 | { | |
443 | struct virtio_vsock *vsock = vq->vdev->priv; | |
444 | ||
445 | if (!vsock) | |
446 | return; | |
447 | queue_work(virtio_vsock_workqueue, &vsock->rx_work); | |
448 | } | |
449 | ||
53efbba1 AK |
450 | static bool virtio_transport_seqpacket_allow(u32 remote_cid); |
451 | ||
0ea9e1d3 AH |
452 | static struct virtio_transport virtio_transport = { |
453 | .transport = { | |
6a2c0962 SG |
454 | .module = THIS_MODULE, |
455 | ||
0ea9e1d3 AH |
456 | .get_local_cid = virtio_transport_get_local_cid, |
457 | ||
458 | .init = virtio_transport_do_socket_init, | |
459 | .destruct = virtio_transport_destruct, | |
460 | .release = virtio_transport_release, | |
461 | .connect = virtio_transport_connect, | |
462 | .shutdown = virtio_transport_shutdown, | |
073b4f2c | 463 | .cancel_pkt = virtio_transport_cancel_pkt, |
0ea9e1d3 AH |
464 | |
465 | .dgram_bind = virtio_transport_dgram_bind, | |
466 | .dgram_dequeue = virtio_transport_dgram_dequeue, | |
467 | .dgram_enqueue = virtio_transport_dgram_enqueue, | |
468 | .dgram_allow = virtio_transport_dgram_allow, | |
469 | ||
470 | .stream_dequeue = virtio_transport_stream_dequeue, | |
471 | .stream_enqueue = virtio_transport_stream_enqueue, | |
472 | .stream_has_data = virtio_transport_stream_has_data, | |
473 | .stream_has_space = virtio_transport_stream_has_space, | |
474 | .stream_rcvhiwat = virtio_transport_stream_rcvhiwat, | |
475 | .stream_is_active = virtio_transport_stream_is_active, | |
476 | .stream_allow = virtio_transport_stream_allow, | |
477 | ||
53efbba1 AK |
478 | .seqpacket_dequeue = virtio_transport_seqpacket_dequeue, |
479 | .seqpacket_enqueue = virtio_transport_seqpacket_enqueue, | |
480 | .seqpacket_allow = virtio_transport_seqpacket_allow, | |
481 | .seqpacket_has_data = virtio_transport_seqpacket_has_data, | |
482 | ||
0ea9e1d3 AH |
483 | .notify_poll_in = virtio_transport_notify_poll_in, |
484 | .notify_poll_out = virtio_transport_notify_poll_out, | |
485 | .notify_recv_init = virtio_transport_notify_recv_init, | |
486 | .notify_recv_pre_block = virtio_transport_notify_recv_pre_block, | |
487 | .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue, | |
488 | .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue, | |
489 | .notify_send_init = virtio_transport_notify_send_init, | |
490 | .notify_send_pre_block = virtio_transport_notify_send_pre_block, | |
491 | .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, | |
492 | .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, | |
b9f2b0ff | 493 | .notify_buffer_size = virtio_transport_notify_buffer_size, |
0ea9e1d3 AH |
494 | }, |
495 | ||
496 | .send_pkt = virtio_transport_send_pkt, | |
497 | }; | |
498 | ||
53efbba1 AK |
499 | static bool virtio_transport_seqpacket_allow(u32 remote_cid) |
500 | { | |
501 | struct virtio_vsock *vsock; | |
502 | bool seqpacket_allow; | |
503 | ||
64295f0d | 504 | seqpacket_allow = false; |
53efbba1 AK |
505 | rcu_read_lock(); |
506 | vsock = rcu_dereference(the_virtio_vsock); | |
64295f0d ED |
507 | if (vsock) |
508 | seqpacket_allow = vsock->seqpacket_allow; | |
53efbba1 AK |
509 | rcu_read_unlock(); |
510 | ||
511 | return seqpacket_allow; | |
512 | } | |
513 | ||
4c7246dc SG |
514 | static void virtio_transport_rx_work(struct work_struct *work) |
515 | { | |
516 | struct virtio_vsock *vsock = | |
517 | container_of(work, struct virtio_vsock, rx_work); | |
518 | struct virtqueue *vq; | |
519 | ||
520 | vq = vsock->vqs[VSOCK_VQ_RX]; | |
521 | ||
522 | mutex_lock(&vsock->rx_lock); | |
523 | ||
524 | if (!vsock->rx_run) | |
525 | goto out; | |
526 | ||
527 | do { | |
528 | virtqueue_disable_cb(vq); | |
529 | for (;;) { | |
530 | struct virtio_vsock_pkt *pkt; | |
531 | unsigned int len; | |
532 | ||
533 | if (!virtio_transport_more_replies(vsock)) { | |
534 | /* Stop rx until the device processes already | |
535 | * pending replies. Leave rx virtqueue | |
536 | * callbacks disabled. | |
537 | */ | |
538 | goto out; | |
539 | } | |
540 | ||
541 | pkt = virtqueue_get_buf(vq, &len); | |
542 | if (!pkt) { | |
543 | break; | |
544 | } | |
545 | ||
546 | vsock->rx_buf_nr--; | |
547 | ||
548 | /* Drop short/long packets */ | |
549 | if (unlikely(len < sizeof(pkt->hdr) || | |
550 | len > sizeof(pkt->hdr) + pkt->len)) { | |
551 | virtio_transport_free_pkt(pkt); | |
552 | continue; | |
553 | } | |
554 | ||
555 | pkt->len = len - sizeof(pkt->hdr); | |
556 | virtio_transport_deliver_tap_pkt(pkt); | |
557 | virtio_transport_recv_pkt(&virtio_transport, pkt); | |
558 | } | |
559 | } while (!virtqueue_enable_cb(vq)); | |
560 | ||
561 | out: | |
562 | if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2) | |
563 | virtio_vsock_rx_fill(vsock); | |
564 | mutex_unlock(&vsock->rx_lock); | |
565 | } | |
566 | ||
0ea9e1d3 AH |
567 | static int virtio_vsock_probe(struct virtio_device *vdev) |
568 | { | |
569 | vq_callback_t *callbacks[] = { | |
570 | virtio_vsock_rx_done, | |
571 | virtio_vsock_tx_done, | |
572 | virtio_vsock_event_done, | |
573 | }; | |
574 | static const char * const names[] = { | |
575 | "rx", | |
576 | "tx", | |
577 | "event", | |
578 | }; | |
579 | struct virtio_vsock *vsock = NULL; | |
580 | int ret; | |
581 | ||
582 | ret = mutex_lock_interruptible(&the_virtio_vsock_mutex); | |
583 | if (ret) | |
584 | return ret; | |
585 | ||
586 | /* Only one virtio-vsock device per guest is supported */ | |
0deab087 SG |
587 | if (rcu_dereference_protected(the_virtio_vsock, |
588 | lockdep_is_held(&the_virtio_vsock_mutex))) { | |
0ea9e1d3 AH |
589 | ret = -EBUSY; |
590 | goto out; | |
591 | } | |
592 | ||
593 | vsock = kzalloc(sizeof(*vsock), GFP_KERNEL); | |
594 | if (!vsock) { | |
595 | ret = -ENOMEM; | |
596 | goto out; | |
597 | } | |
598 | ||
599 | vsock->vdev = vdev; | |
600 | ||
9b2bbdb2 MT |
601 | ret = virtio_find_vqs(vsock->vdev, VSOCK_VQ_MAX, |
602 | vsock->vqs, callbacks, names, | |
603 | NULL); | |
0ea9e1d3 AH |
604 | if (ret < 0) |
605 | goto out; | |
606 | ||
607 | virtio_vsock_update_guest_cid(vsock); | |
608 | ||
0ea9e1d3 AH |
609 | vsock->rx_buf_nr = 0; |
610 | vsock->rx_buf_max_nr = 0; | |
611 | atomic_set(&vsock->queued_replies, 0); | |
612 | ||
0ea9e1d3 AH |
613 | mutex_init(&vsock->tx_lock); |
614 | mutex_init(&vsock->rx_lock); | |
615 | mutex_init(&vsock->event_lock); | |
616 | spin_lock_init(&vsock->send_pkt_list_lock); | |
617 | INIT_LIST_HEAD(&vsock->send_pkt_list); | |
618 | INIT_WORK(&vsock->rx_work, virtio_transport_rx_work); | |
619 | INIT_WORK(&vsock->tx_work, virtio_transport_tx_work); | |
620 | INIT_WORK(&vsock->event_work, virtio_transport_event_work); | |
621 | INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work); | |
622 | ||
b917507e SG |
623 | mutex_lock(&vsock->tx_lock); |
624 | vsock->tx_run = true; | |
625 | mutex_unlock(&vsock->tx_lock); | |
626 | ||
0ea9e1d3 AH |
627 | mutex_lock(&vsock->rx_lock); |
628 | virtio_vsock_rx_fill(vsock); | |
b917507e | 629 | vsock->rx_run = true; |
0ea9e1d3 AH |
630 | mutex_unlock(&vsock->rx_lock); |
631 | ||
632 | mutex_lock(&vsock->event_lock); | |
633 | virtio_vsock_event_fill(vsock); | |
b917507e | 634 | vsock->event_run = true; |
0ea9e1d3 AH |
635 | mutex_unlock(&vsock->event_lock); |
636 | ||
53efbba1 AK |
637 | if (virtio_has_feature(vdev, VIRTIO_VSOCK_F_SEQPACKET)) |
638 | vsock->seqpacket_allow = true; | |
639 | ||
0deab087 SG |
640 | vdev->priv = vsock; |
641 | rcu_assign_pointer(the_virtio_vsock, vsock); | |
642 | ||
0ea9e1d3 | 643 | mutex_unlock(&the_virtio_vsock_mutex); |
53efbba1 | 644 | |
0ea9e1d3 AH |
645 | return 0; |
646 | ||
0ea9e1d3 AH |
647 | out: |
648 | kfree(vsock); | |
649 | mutex_unlock(&the_virtio_vsock_mutex); | |
650 | return ret; | |
651 | } | |
652 | ||
653 | static void virtio_vsock_remove(struct virtio_device *vdev) | |
654 | { | |
655 | struct virtio_vsock *vsock = vdev->priv; | |
656 | struct virtio_vsock_pkt *pkt; | |
657 | ||
0deab087 SG |
658 | mutex_lock(&the_virtio_vsock_mutex); |
659 | ||
660 | vdev->priv = NULL; | |
661 | rcu_assign_pointer(the_virtio_vsock, NULL); | |
662 | synchronize_rcu(); | |
663 | ||
85965487 SG |
664 | /* Reset all connected sockets when the device disappear */ |
665 | vsock_for_each_connected_socket(virtio_vsock_reset_sock); | |
666 | ||
b917507e SG |
667 | /* Stop all work handlers to make sure no one is accessing the device, |
668 | * so we can safely call vdev->config->reset(). | |
669 | */ | |
670 | mutex_lock(&vsock->rx_lock); | |
671 | vsock->rx_run = false; | |
672 | mutex_unlock(&vsock->rx_lock); | |
673 | ||
674 | mutex_lock(&vsock->tx_lock); | |
675 | vsock->tx_run = false; | |
676 | mutex_unlock(&vsock->tx_lock); | |
677 | ||
678 | mutex_lock(&vsock->event_lock); | |
679 | vsock->event_run = false; | |
680 | mutex_unlock(&vsock->event_lock); | |
681 | ||
682 | /* Flush all device writes and interrupts, device will not use any | |
683 | * more buffers. | |
684 | */ | |
0ea9e1d3 AH |
685 | vdev->config->reset(vdev); |
686 | ||
687 | mutex_lock(&vsock->rx_lock); | |
688 | while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX]))) | |
689 | virtio_transport_free_pkt(pkt); | |
690 | mutex_unlock(&vsock->rx_lock); | |
691 | ||
692 | mutex_lock(&vsock->tx_lock); | |
693 | while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX]))) | |
694 | virtio_transport_free_pkt(pkt); | |
695 | mutex_unlock(&vsock->tx_lock); | |
696 | ||
697 | spin_lock_bh(&vsock->send_pkt_list_lock); | |
698 | while (!list_empty(&vsock->send_pkt_list)) { | |
699 | pkt = list_first_entry(&vsock->send_pkt_list, | |
700 | struct virtio_vsock_pkt, list); | |
701 | list_del(&pkt->list); | |
702 | virtio_transport_free_pkt(pkt); | |
703 | } | |
704 | spin_unlock_bh(&vsock->send_pkt_list_lock); | |
705 | ||
b917507e | 706 | /* Delete virtqueues and flush outstanding callbacks if any */ |
0ea9e1d3 AH |
707 | vdev->config->del_vqs(vdev); |
708 | ||
e226121f SG |
709 | /* Other works can be queued before 'config->del_vqs()', so we flush |
710 | * all works before to free the vsock object to avoid use after free. | |
711 | */ | |
e226121f SG |
712 | flush_work(&vsock->rx_work); |
713 | flush_work(&vsock->tx_work); | |
714 | flush_work(&vsock->event_work); | |
715 | flush_work(&vsock->send_pkt_work); | |
716 | ||
0deab087 SG |
717 | mutex_unlock(&the_virtio_vsock_mutex); |
718 | ||
0ea9e1d3 AH |
719 | kfree(vsock); |
720 | } | |
721 | ||
722 | static struct virtio_device_id id_table[] = { | |
723 | { VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID }, | |
724 | { 0 }, | |
725 | }; | |
726 | ||
727 | static unsigned int features[] = { | |
53efbba1 | 728 | VIRTIO_VSOCK_F_SEQPACKET |
0ea9e1d3 AH |
729 | }; |
730 | ||
731 | static struct virtio_driver virtio_vsock_driver = { | |
732 | .feature_table = features, | |
733 | .feature_table_size = ARRAY_SIZE(features), | |
734 | .driver.name = KBUILD_MODNAME, | |
735 | .driver.owner = THIS_MODULE, | |
736 | .id_table = id_table, | |
737 | .probe = virtio_vsock_probe, | |
738 | .remove = virtio_vsock_remove, | |
739 | }; | |
740 | ||
741 | static int __init virtio_vsock_init(void) | |
742 | { | |
743 | int ret; | |
744 | ||
745 | virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0); | |
746 | if (!virtio_vsock_workqueue) | |
747 | return -ENOMEM; | |
22b5c0b6 | 748 | |
c0cfa2d8 SG |
749 | ret = vsock_core_register(&virtio_transport.transport, |
750 | VSOCK_TRANSPORT_F_G2H); | |
0ea9e1d3 | 751 | if (ret) |
22b5c0b6 SG |
752 | goto out_wq; |
753 | ||
ba95e5df | 754 | ret = register_virtio_driver(&virtio_vsock_driver); |
22b5c0b6 | 755 | if (ret) |
ba95e5df | 756 | goto out_vci; |
22b5c0b6 SG |
757 | |
758 | return 0; | |
759 | ||
ba95e5df | 760 | out_vci: |
c0cfa2d8 | 761 | vsock_core_unregister(&virtio_transport.transport); |
22b5c0b6 SG |
762 | out_wq: |
763 | destroy_workqueue(virtio_vsock_workqueue); | |
0ea9e1d3 AH |
764 | return ret; |
765 | } | |
766 | ||
767 | static void __exit virtio_vsock_exit(void) | |
768 | { | |
769 | unregister_virtio_driver(&virtio_vsock_driver); | |
c0cfa2d8 | 770 | vsock_core_unregister(&virtio_transport.transport); |
0ea9e1d3 AH |
771 | destroy_workqueue(virtio_vsock_workqueue); |
772 | } | |
773 | ||
774 | module_init(virtio_vsock_init); | |
775 | module_exit(virtio_vsock_exit); | |
776 | MODULE_LICENSE("GPL v2"); | |
777 | MODULE_AUTHOR("Asias He"); | |
778 | MODULE_DESCRIPTION("virtio transport for vsock"); | |
779 | MODULE_DEVICE_TABLE(virtio, id_table); |