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3a4d5c94 MT |
1 | /* Copyright (C) 2009 Red Hat, Inc. |
2 | * Author: Michael S. Tsirkin <mst@redhat.com> | |
3 | * | |
4 | * This work is licensed under the terms of the GNU GPL, version 2. | |
5 | * | |
6 | * virtio-net server in host kernel. | |
7 | */ | |
8 | ||
9 | #include <linux/compat.h> | |
10 | #include <linux/eventfd.h> | |
11 | #include <linux/vhost.h> | |
12 | #include <linux/virtio_net.h> | |
13 | #include <linux/mmu_context.h> | |
14 | #include <linux/miscdevice.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/mutex.h> | |
17 | #include <linux/workqueue.h> | |
18 | #include <linux/rcupdate.h> | |
19 | #include <linux/file.h> | |
5a0e3ad6 | 20 | #include <linux/slab.h> |
3a4d5c94 MT |
21 | |
22 | #include <linux/net.h> | |
23 | #include <linux/if_packet.h> | |
24 | #include <linux/if_arp.h> | |
25 | #include <linux/if_tun.h> | |
501c774c | 26 | #include <linux/if_macvlan.h> |
3a4d5c94 MT |
27 | |
28 | #include <net/sock.h> | |
29 | ||
30 | #include "vhost.h" | |
31 | ||
32 | /* Max number of bytes transferred before requeueing the job. | |
33 | * Using this limit prevents one virtqueue from starving others. */ | |
34 | #define VHOST_NET_WEIGHT 0x80000 | |
35 | ||
36 | enum { | |
37 | VHOST_NET_VQ_RX = 0, | |
38 | VHOST_NET_VQ_TX = 1, | |
39 | VHOST_NET_VQ_MAX = 2, | |
40 | }; | |
41 | ||
42 | enum vhost_net_poll_state { | |
43 | VHOST_NET_POLL_DISABLED = 0, | |
44 | VHOST_NET_POLL_STARTED = 1, | |
45 | VHOST_NET_POLL_STOPPED = 2, | |
46 | }; | |
47 | ||
48 | struct vhost_net { | |
49 | struct vhost_dev dev; | |
50 | struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX]; | |
51 | struct vhost_poll poll[VHOST_NET_VQ_MAX]; | |
52 | /* Tells us whether we are polling a socket for TX. | |
53 | * We only do this when socket buffer fills up. | |
54 | * Protected by tx vq lock. */ | |
55 | enum vhost_net_poll_state tx_poll_state; | |
56 | }; | |
57 | ||
58 | /* Pop first len bytes from iovec. Return number of segments used. */ | |
59 | static int move_iovec_hdr(struct iovec *from, struct iovec *to, | |
60 | size_t len, int iov_count) | |
61 | { | |
62 | int seg = 0; | |
63 | size_t size; | |
64 | while (len && seg < iov_count) { | |
65 | size = min(from->iov_len, len); | |
66 | to->iov_base = from->iov_base; | |
67 | to->iov_len = size; | |
68 | from->iov_len -= size; | |
69 | from->iov_base += size; | |
70 | len -= size; | |
71 | ++from; | |
72 | ++to; | |
73 | ++seg; | |
74 | } | |
75 | return seg; | |
76 | } | |
8dd014ad DS |
77 | /* Copy iovec entries for len bytes from iovec. */ |
78 | static void copy_iovec_hdr(const struct iovec *from, struct iovec *to, | |
79 | size_t len, int iovcount) | |
80 | { | |
81 | int seg = 0; | |
82 | size_t size; | |
83 | while (len && seg < iovcount) { | |
84 | size = min(from->iov_len, len); | |
85 | to->iov_base = from->iov_base; | |
86 | to->iov_len = size; | |
87 | len -= size; | |
88 | ++from; | |
89 | ++to; | |
90 | ++seg; | |
91 | } | |
92 | } | |
3a4d5c94 MT |
93 | |
94 | /* Caller must have TX VQ lock */ | |
95 | static void tx_poll_stop(struct vhost_net *net) | |
96 | { | |
97 | if (likely(net->tx_poll_state != VHOST_NET_POLL_STARTED)) | |
98 | return; | |
99 | vhost_poll_stop(net->poll + VHOST_NET_VQ_TX); | |
100 | net->tx_poll_state = VHOST_NET_POLL_STOPPED; | |
101 | } | |
102 | ||
103 | /* Caller must have TX VQ lock */ | |
104 | static void tx_poll_start(struct vhost_net *net, struct socket *sock) | |
105 | { | |
106 | if (unlikely(net->tx_poll_state != VHOST_NET_POLL_STOPPED)) | |
107 | return; | |
108 | vhost_poll_start(net->poll + VHOST_NET_VQ_TX, sock->file); | |
109 | net->tx_poll_state = VHOST_NET_POLL_STARTED; | |
110 | } | |
111 | ||
112 | /* Expects to be always run from workqueue - which acts as | |
113 | * read-size critical section for our kind of RCU. */ | |
114 | static void handle_tx(struct vhost_net *net) | |
115 | { | |
116 | struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX]; | |
d5675bd2 MT |
117 | unsigned out, in, s; |
118 | int head; | |
3a4d5c94 MT |
119 | struct msghdr msg = { |
120 | .msg_name = NULL, | |
121 | .msg_namelen = 0, | |
122 | .msg_control = NULL, | |
123 | .msg_controllen = 0, | |
124 | .msg_iov = vq->iov, | |
125 | .msg_flags = MSG_DONTWAIT, | |
126 | }; | |
127 | size_t len, total_len = 0; | |
128 | int err, wmem; | |
129 | size_t hdr_size; | |
28457ee6 AB |
130 | struct socket *sock; |
131 | ||
132 | sock = rcu_dereference_check(vq->private_data, | |
133 | lockdep_is_held(&vq->mutex)); | |
3a4d5c94 MT |
134 | if (!sock) |
135 | return; | |
136 | ||
137 | wmem = atomic_read(&sock->sk->sk_wmem_alloc); | |
39286fa4 SS |
138 | if (wmem >= sock->sk->sk_sndbuf) { |
139 | mutex_lock(&vq->mutex); | |
140 | tx_poll_start(net, sock); | |
141 | mutex_unlock(&vq->mutex); | |
3a4d5c94 | 142 | return; |
39286fa4 | 143 | } |
3a4d5c94 MT |
144 | |
145 | use_mm(net->dev.mm); | |
146 | mutex_lock(&vq->mutex); | |
147 | vhost_disable_notify(vq); | |
148 | ||
0e255572 | 149 | if (wmem < sock->sk->sk_sndbuf / 2) |
3a4d5c94 | 150 | tx_poll_stop(net); |
8dd014ad | 151 | hdr_size = vq->vhost_hlen; |
3a4d5c94 MT |
152 | |
153 | for (;;) { | |
154 | head = vhost_get_vq_desc(&net->dev, vq, vq->iov, | |
155 | ARRAY_SIZE(vq->iov), | |
156 | &out, &in, | |
157 | NULL, NULL); | |
d5675bd2 | 158 | /* On error, stop handling until the next kick. */ |
7b3384fc | 159 | if (unlikely(head < 0)) |
d5675bd2 | 160 | break; |
3a4d5c94 MT |
161 | /* Nothing new? Wait for eventfd to tell us they refilled. */ |
162 | if (head == vq->num) { | |
163 | wmem = atomic_read(&sock->sk->sk_wmem_alloc); | |
164 | if (wmem >= sock->sk->sk_sndbuf * 3 / 4) { | |
165 | tx_poll_start(net, sock); | |
166 | set_bit(SOCK_ASYNC_NOSPACE, &sock->flags); | |
167 | break; | |
168 | } | |
169 | if (unlikely(vhost_enable_notify(vq))) { | |
170 | vhost_disable_notify(vq); | |
171 | continue; | |
172 | } | |
173 | break; | |
174 | } | |
175 | if (in) { | |
176 | vq_err(vq, "Unexpected descriptor format for TX: " | |
177 | "out %d, int %d\n", out, in); | |
178 | break; | |
179 | } | |
180 | /* Skip header. TODO: support TSO. */ | |
181 | s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, out); | |
182 | msg.msg_iovlen = out; | |
183 | len = iov_length(vq->iov, out); | |
184 | /* Sanity check */ | |
185 | if (!len) { | |
186 | vq_err(vq, "Unexpected header len for TX: " | |
187 | "%zd expected %zd\n", | |
188 | iov_length(vq->hdr, s), hdr_size); | |
189 | break; | |
190 | } | |
191 | /* TODO: Check specific error and bomb out unless ENOBUFS? */ | |
192 | err = sock->ops->sendmsg(NULL, sock, &msg, len); | |
193 | if (unlikely(err < 0)) { | |
8dd014ad | 194 | vhost_discard_vq_desc(vq, 1); |
3a4d5c94 MT |
195 | tx_poll_start(net, sock); |
196 | break; | |
197 | } | |
198 | if (err != len) | |
95c0ec6a MT |
199 | pr_debug("Truncated TX packet: " |
200 | " len %d != %zd\n", err, len); | |
3a4d5c94 MT |
201 | vhost_add_used_and_signal(&net->dev, vq, head, 0); |
202 | total_len += len; | |
203 | if (unlikely(total_len >= VHOST_NET_WEIGHT)) { | |
204 | vhost_poll_queue(&vq->poll); | |
205 | break; | |
206 | } | |
207 | } | |
208 | ||
209 | mutex_unlock(&vq->mutex); | |
210 | unuse_mm(net->dev.mm); | |
211 | } | |
212 | ||
8dd014ad DS |
213 | static int peek_head_len(struct sock *sk) |
214 | { | |
215 | struct sk_buff *head; | |
216 | int len = 0; | |
217 | ||
218 | lock_sock(sk); | |
219 | head = skb_peek(&sk->sk_receive_queue); | |
220 | if (head) | |
221 | len = head->len; | |
222 | release_sock(sk); | |
223 | return len; | |
224 | } | |
225 | ||
226 | /* This is a multi-buffer version of vhost_get_desc, that works if | |
227 | * vq has read descriptors only. | |
228 | * @vq - the relevant virtqueue | |
229 | * @datalen - data length we'll be reading | |
230 | * @iovcount - returned count of io vectors we fill | |
231 | * @log - vhost log | |
232 | * @log_num - log offset | |
233 | * returns number of buffer heads allocated, negative on error | |
234 | */ | |
235 | static int get_rx_bufs(struct vhost_virtqueue *vq, | |
236 | struct vring_used_elem *heads, | |
237 | int datalen, | |
238 | unsigned *iovcount, | |
239 | struct vhost_log *log, | |
240 | unsigned *log_num) | |
241 | { | |
242 | unsigned int out, in; | |
243 | int seg = 0; | |
244 | int headcount = 0; | |
245 | unsigned d; | |
246 | int r, nlogs = 0; | |
247 | ||
248 | while (datalen > 0) { | |
e0e9b406 | 249 | if (unlikely(seg >= UIO_MAXIOV)) { |
8dd014ad DS |
250 | r = -ENOBUFS; |
251 | goto err; | |
252 | } | |
253 | d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg, | |
254 | ARRAY_SIZE(vq->iov) - seg, &out, | |
255 | &in, log, log_num); | |
256 | if (d == vq->num) { | |
257 | r = 0; | |
258 | goto err; | |
259 | } | |
260 | if (unlikely(out || in <= 0)) { | |
261 | vq_err(vq, "unexpected descriptor format for RX: " | |
262 | "out %d, in %d\n", out, in); | |
263 | r = -EINVAL; | |
264 | goto err; | |
265 | } | |
266 | if (unlikely(log)) { | |
267 | nlogs += *log_num; | |
268 | log += *log_num; | |
269 | } | |
270 | heads[headcount].id = d; | |
271 | heads[headcount].len = iov_length(vq->iov + seg, in); | |
272 | datalen -= heads[headcount].len; | |
273 | ++headcount; | |
274 | seg += in; | |
275 | } | |
276 | heads[headcount - 1].len += datalen; | |
277 | *iovcount = seg; | |
278 | if (unlikely(log)) | |
279 | *log_num = nlogs; | |
280 | return headcount; | |
281 | err: | |
282 | vhost_discard_vq_desc(vq, headcount); | |
283 | return r; | |
284 | } | |
285 | ||
3a4d5c94 MT |
286 | /* Expects to be always run from workqueue - which acts as |
287 | * read-size critical section for our kind of RCU. */ | |
8dd014ad | 288 | static void handle_rx_big(struct vhost_net *net) |
3a4d5c94 MT |
289 | { |
290 | struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX]; | |
d5675bd2 MT |
291 | unsigned out, in, log, s; |
292 | int head; | |
3a4d5c94 MT |
293 | struct vhost_log *vq_log; |
294 | struct msghdr msg = { | |
295 | .msg_name = NULL, | |
296 | .msg_namelen = 0, | |
297 | .msg_control = NULL, /* FIXME: get and handle RX aux data. */ | |
298 | .msg_controllen = 0, | |
299 | .msg_iov = vq->iov, | |
300 | .msg_flags = MSG_DONTWAIT, | |
301 | }; | |
302 | ||
303 | struct virtio_net_hdr hdr = { | |
304 | .flags = 0, | |
305 | .gso_type = VIRTIO_NET_HDR_GSO_NONE | |
306 | }; | |
307 | ||
308 | size_t len, total_len = 0; | |
309 | int err; | |
310 | size_t hdr_size; | |
311 | struct socket *sock = rcu_dereference(vq->private_data); | |
312 | if (!sock || skb_queue_empty(&sock->sk->sk_receive_queue)) | |
313 | return; | |
314 | ||
315 | use_mm(net->dev.mm); | |
316 | mutex_lock(&vq->mutex); | |
317 | vhost_disable_notify(vq); | |
8dd014ad | 318 | hdr_size = vq->vhost_hlen; |
3a4d5c94 MT |
319 | |
320 | vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ? | |
321 | vq->log : NULL; | |
322 | ||
323 | for (;;) { | |
324 | head = vhost_get_vq_desc(&net->dev, vq, vq->iov, | |
325 | ARRAY_SIZE(vq->iov), | |
326 | &out, &in, | |
327 | vq_log, &log); | |
d5675bd2 | 328 | /* On error, stop handling until the next kick. */ |
7b3384fc | 329 | if (unlikely(head < 0)) |
d5675bd2 | 330 | break; |
3a4d5c94 MT |
331 | /* OK, now we need to know about added descriptors. */ |
332 | if (head == vq->num) { | |
333 | if (unlikely(vhost_enable_notify(vq))) { | |
334 | /* They have slipped one in as we were | |
335 | * doing that: check again. */ | |
336 | vhost_disable_notify(vq); | |
337 | continue; | |
338 | } | |
339 | /* Nothing new? Wait for eventfd to tell us | |
340 | * they refilled. */ | |
341 | break; | |
342 | } | |
343 | /* We don't need to be notified again. */ | |
344 | if (out) { | |
345 | vq_err(vq, "Unexpected descriptor format for RX: " | |
346 | "out %d, int %d\n", | |
347 | out, in); | |
348 | break; | |
349 | } | |
350 | /* Skip header. TODO: support TSO/mergeable rx buffers. */ | |
351 | s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, in); | |
352 | msg.msg_iovlen = in; | |
353 | len = iov_length(vq->iov, in); | |
354 | /* Sanity check */ | |
355 | if (!len) { | |
356 | vq_err(vq, "Unexpected header len for RX: " | |
357 | "%zd expected %zd\n", | |
358 | iov_length(vq->hdr, s), hdr_size); | |
359 | break; | |
360 | } | |
361 | err = sock->ops->recvmsg(NULL, sock, &msg, | |
362 | len, MSG_DONTWAIT | MSG_TRUNC); | |
363 | /* TODO: Check specific error and bomb out unless EAGAIN? */ | |
364 | if (err < 0) { | |
8dd014ad | 365 | vhost_discard_vq_desc(vq, 1); |
3a4d5c94 MT |
366 | break; |
367 | } | |
368 | /* TODO: Should check and handle checksum. */ | |
369 | if (err > len) { | |
95c0ec6a MT |
370 | pr_debug("Discarded truncated rx packet: " |
371 | " len %d > %zd\n", err, len); | |
8dd014ad | 372 | vhost_discard_vq_desc(vq, 1); |
3a4d5c94 MT |
373 | continue; |
374 | } | |
375 | len = err; | |
376 | err = memcpy_toiovec(vq->hdr, (unsigned char *)&hdr, hdr_size); | |
377 | if (err) { | |
378 | vq_err(vq, "Unable to write vnet_hdr at addr %p: %d\n", | |
379 | vq->iov->iov_base, err); | |
380 | break; | |
381 | } | |
382 | len += hdr_size; | |
383 | vhost_add_used_and_signal(&net->dev, vq, head, len); | |
384 | if (unlikely(vq_log)) | |
385 | vhost_log_write(vq, vq_log, log, len); | |
386 | total_len += len; | |
387 | if (unlikely(total_len >= VHOST_NET_WEIGHT)) { | |
388 | vhost_poll_queue(&vq->poll); | |
389 | break; | |
390 | } | |
391 | } | |
392 | ||
393 | mutex_unlock(&vq->mutex); | |
394 | unuse_mm(net->dev.mm); | |
395 | } | |
396 | ||
8dd014ad DS |
397 | /* Expects to be always run from workqueue - which acts as |
398 | * read-size critical section for our kind of RCU. */ | |
399 | static void handle_rx_mergeable(struct vhost_net *net) | |
3a4d5c94 | 400 | { |
8dd014ad DS |
401 | struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX]; |
402 | unsigned uninitialized_var(in), log; | |
403 | struct vhost_log *vq_log; | |
404 | struct msghdr msg = { | |
405 | .msg_name = NULL, | |
406 | .msg_namelen = 0, | |
407 | .msg_control = NULL, /* FIXME: get and handle RX aux data. */ | |
408 | .msg_controllen = 0, | |
409 | .msg_iov = vq->iov, | |
410 | .msg_flags = MSG_DONTWAIT, | |
411 | }; | |
412 | ||
413 | struct virtio_net_hdr_mrg_rxbuf hdr = { | |
414 | .hdr.flags = 0, | |
415 | .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE | |
416 | }; | |
417 | ||
418 | size_t total_len = 0; | |
419 | int err, headcount; | |
420 | size_t vhost_hlen, sock_hlen; | |
421 | size_t vhost_len, sock_len; | |
422 | struct socket *sock = rcu_dereference(vq->private_data); | |
423 | if (!sock || skb_queue_empty(&sock->sk->sk_receive_queue)) | |
424 | return; | |
425 | ||
426 | use_mm(net->dev.mm); | |
427 | mutex_lock(&vq->mutex); | |
428 | vhost_disable_notify(vq); | |
429 | vhost_hlen = vq->vhost_hlen; | |
430 | sock_hlen = vq->sock_hlen; | |
431 | ||
432 | vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ? | |
433 | vq->log : NULL; | |
434 | ||
435 | while ((sock_len = peek_head_len(sock->sk))) { | |
436 | sock_len += sock_hlen; | |
437 | vhost_len = sock_len + vhost_hlen; | |
438 | headcount = get_rx_bufs(vq, vq->heads, vhost_len, | |
439 | &in, vq_log, &log); | |
440 | /* On error, stop handling until the next kick. */ | |
441 | if (unlikely(headcount < 0)) | |
442 | break; | |
443 | /* OK, now we need to know about added descriptors. */ | |
444 | if (!headcount) { | |
445 | if (unlikely(vhost_enable_notify(vq))) { | |
446 | /* They have slipped one in as we were | |
447 | * doing that: check again. */ | |
448 | vhost_disable_notify(vq); | |
449 | continue; | |
450 | } | |
451 | /* Nothing new? Wait for eventfd to tell us | |
452 | * they refilled. */ | |
453 | break; | |
454 | } | |
455 | /* We don't need to be notified again. */ | |
456 | if (unlikely((vhost_hlen))) | |
457 | /* Skip header. TODO: support TSO. */ | |
458 | move_iovec_hdr(vq->iov, vq->hdr, vhost_hlen, in); | |
459 | else | |
460 | /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF: | |
461 | * needed because sendmsg can modify msg_iov. */ | |
462 | copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in); | |
463 | msg.msg_iovlen = in; | |
464 | err = sock->ops->recvmsg(NULL, sock, &msg, | |
465 | sock_len, MSG_DONTWAIT | MSG_TRUNC); | |
466 | /* Userspace might have consumed the packet meanwhile: | |
467 | * it's not supposed to do this usually, but might be hard | |
468 | * to prevent. Discard data we got (if any) and keep going. */ | |
469 | if (unlikely(err != sock_len)) { | |
470 | pr_debug("Discarded rx packet: " | |
471 | " len %d, expected %zd\n", err, sock_len); | |
472 | vhost_discard_vq_desc(vq, headcount); | |
473 | continue; | |
474 | } | |
475 | if (unlikely(vhost_hlen) && | |
476 | memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0, | |
477 | vhost_hlen)) { | |
478 | vq_err(vq, "Unable to write vnet_hdr at addr %p\n", | |
479 | vq->iov->iov_base); | |
480 | break; | |
481 | } | |
482 | /* TODO: Should check and handle checksum. */ | |
483 | if (vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF) && | |
484 | memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount, | |
485 | offsetof(typeof(hdr), num_buffers), | |
486 | sizeof hdr.num_buffers)) { | |
487 | vq_err(vq, "Failed num_buffers write"); | |
488 | vhost_discard_vq_desc(vq, headcount); | |
489 | break; | |
490 | } | |
491 | vhost_add_used_and_signal_n(&net->dev, vq, vq->heads, | |
492 | headcount); | |
493 | if (unlikely(vq_log)) | |
494 | vhost_log_write(vq, vq_log, log, vhost_len); | |
495 | total_len += vhost_len; | |
496 | if (unlikely(total_len >= VHOST_NET_WEIGHT)) { | |
497 | vhost_poll_queue(&vq->poll); | |
498 | break; | |
499 | } | |
500 | } | |
501 | ||
502 | mutex_unlock(&vq->mutex); | |
503 | unuse_mm(net->dev.mm); | |
504 | } | |
505 | ||
506 | static void handle_rx(struct vhost_net *net) | |
507 | { | |
508 | if (vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF)) | |
509 | handle_rx_mergeable(net); | |
510 | else | |
511 | handle_rx_big(net); | |
512 | } | |
513 | ||
c23f3445 | 514 | static void handle_tx_kick(struct vhost_work *work) |
3a4d5c94 | 515 | { |
c23f3445 TH |
516 | struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, |
517 | poll.work); | |
518 | struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev); | |
519 | ||
3a4d5c94 MT |
520 | handle_tx(net); |
521 | } | |
522 | ||
c23f3445 | 523 | static void handle_rx_kick(struct vhost_work *work) |
3a4d5c94 | 524 | { |
c23f3445 TH |
525 | struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, |
526 | poll.work); | |
527 | struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev); | |
528 | ||
3a4d5c94 MT |
529 | handle_rx(net); |
530 | } | |
531 | ||
c23f3445 | 532 | static void handle_tx_net(struct vhost_work *work) |
3a4d5c94 | 533 | { |
c23f3445 TH |
534 | struct vhost_net *net = container_of(work, struct vhost_net, |
535 | poll[VHOST_NET_VQ_TX].work); | |
3a4d5c94 MT |
536 | handle_tx(net); |
537 | } | |
538 | ||
c23f3445 | 539 | static void handle_rx_net(struct vhost_work *work) |
3a4d5c94 | 540 | { |
c23f3445 TH |
541 | struct vhost_net *net = container_of(work, struct vhost_net, |
542 | poll[VHOST_NET_VQ_RX].work); | |
3a4d5c94 MT |
543 | handle_rx(net); |
544 | } | |
545 | ||
546 | static int vhost_net_open(struct inode *inode, struct file *f) | |
547 | { | |
548 | struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL); | |
c23f3445 | 549 | struct vhost_dev *dev; |
3a4d5c94 | 550 | int r; |
c23f3445 | 551 | |
3a4d5c94 MT |
552 | if (!n) |
553 | return -ENOMEM; | |
c23f3445 TH |
554 | |
555 | dev = &n->dev; | |
3a4d5c94 MT |
556 | n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick; |
557 | n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick; | |
c23f3445 | 558 | r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX); |
3a4d5c94 MT |
559 | if (r < 0) { |
560 | kfree(n); | |
561 | return r; | |
562 | } | |
563 | ||
c23f3445 TH |
564 | vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev); |
565 | vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev); | |
3a4d5c94 MT |
566 | n->tx_poll_state = VHOST_NET_POLL_DISABLED; |
567 | ||
568 | f->private_data = n; | |
569 | ||
570 | return 0; | |
571 | } | |
572 | ||
573 | static void vhost_net_disable_vq(struct vhost_net *n, | |
574 | struct vhost_virtqueue *vq) | |
575 | { | |
576 | if (!vq->private_data) | |
577 | return; | |
578 | if (vq == n->vqs + VHOST_NET_VQ_TX) { | |
579 | tx_poll_stop(n); | |
580 | n->tx_poll_state = VHOST_NET_POLL_DISABLED; | |
581 | } else | |
582 | vhost_poll_stop(n->poll + VHOST_NET_VQ_RX); | |
583 | } | |
584 | ||
585 | static void vhost_net_enable_vq(struct vhost_net *n, | |
586 | struct vhost_virtqueue *vq) | |
587 | { | |
28457ee6 AB |
588 | struct socket *sock; |
589 | ||
590 | sock = rcu_dereference_protected(vq->private_data, | |
591 | lockdep_is_held(&vq->mutex)); | |
3a4d5c94 MT |
592 | if (!sock) |
593 | return; | |
594 | if (vq == n->vqs + VHOST_NET_VQ_TX) { | |
595 | n->tx_poll_state = VHOST_NET_POLL_STOPPED; | |
596 | tx_poll_start(n, sock); | |
597 | } else | |
598 | vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file); | |
599 | } | |
600 | ||
601 | static struct socket *vhost_net_stop_vq(struct vhost_net *n, | |
602 | struct vhost_virtqueue *vq) | |
603 | { | |
604 | struct socket *sock; | |
605 | ||
606 | mutex_lock(&vq->mutex); | |
28457ee6 AB |
607 | sock = rcu_dereference_protected(vq->private_data, |
608 | lockdep_is_held(&vq->mutex)); | |
3a4d5c94 MT |
609 | vhost_net_disable_vq(n, vq); |
610 | rcu_assign_pointer(vq->private_data, NULL); | |
611 | mutex_unlock(&vq->mutex); | |
612 | return sock; | |
613 | } | |
614 | ||
615 | static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock, | |
616 | struct socket **rx_sock) | |
617 | { | |
618 | *tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX); | |
619 | *rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX); | |
620 | } | |
621 | ||
622 | static void vhost_net_flush_vq(struct vhost_net *n, int index) | |
623 | { | |
624 | vhost_poll_flush(n->poll + index); | |
625 | vhost_poll_flush(&n->dev.vqs[index].poll); | |
626 | } | |
627 | ||
628 | static void vhost_net_flush(struct vhost_net *n) | |
629 | { | |
630 | vhost_net_flush_vq(n, VHOST_NET_VQ_TX); | |
631 | vhost_net_flush_vq(n, VHOST_NET_VQ_RX); | |
632 | } | |
633 | ||
634 | static int vhost_net_release(struct inode *inode, struct file *f) | |
635 | { | |
636 | struct vhost_net *n = f->private_data; | |
637 | struct socket *tx_sock; | |
638 | struct socket *rx_sock; | |
639 | ||
640 | vhost_net_stop(n, &tx_sock, &rx_sock); | |
641 | vhost_net_flush(n); | |
642 | vhost_dev_cleanup(&n->dev); | |
643 | if (tx_sock) | |
644 | fput(tx_sock->file); | |
645 | if (rx_sock) | |
646 | fput(rx_sock->file); | |
647 | /* We do an extra flush before freeing memory, | |
648 | * since jobs can re-queue themselves. */ | |
649 | vhost_net_flush(n); | |
650 | kfree(n); | |
651 | return 0; | |
652 | } | |
653 | ||
654 | static struct socket *get_raw_socket(int fd) | |
655 | { | |
656 | struct { | |
657 | struct sockaddr_ll sa; | |
658 | char buf[MAX_ADDR_LEN]; | |
659 | } uaddr; | |
660 | int uaddr_len = sizeof uaddr, r; | |
661 | struct socket *sock = sockfd_lookup(fd, &r); | |
662 | if (!sock) | |
663 | return ERR_PTR(-ENOTSOCK); | |
664 | ||
665 | /* Parameter checking */ | |
666 | if (sock->sk->sk_type != SOCK_RAW) { | |
667 | r = -ESOCKTNOSUPPORT; | |
668 | goto err; | |
669 | } | |
670 | ||
671 | r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa, | |
672 | &uaddr_len, 0); | |
673 | if (r) | |
674 | goto err; | |
675 | ||
676 | if (uaddr.sa.sll_family != AF_PACKET) { | |
677 | r = -EPFNOSUPPORT; | |
678 | goto err; | |
679 | } | |
680 | return sock; | |
681 | err: | |
682 | fput(sock->file); | |
683 | return ERR_PTR(r); | |
684 | } | |
685 | ||
501c774c | 686 | static struct socket *get_tap_socket(int fd) |
3a4d5c94 MT |
687 | { |
688 | struct file *file = fget(fd); | |
689 | struct socket *sock; | |
690 | if (!file) | |
691 | return ERR_PTR(-EBADF); | |
692 | sock = tun_get_socket(file); | |
501c774c AB |
693 | if (!IS_ERR(sock)) |
694 | return sock; | |
695 | sock = macvtap_get_socket(file); | |
3a4d5c94 MT |
696 | if (IS_ERR(sock)) |
697 | fput(file); | |
698 | return sock; | |
699 | } | |
700 | ||
701 | static struct socket *get_socket(int fd) | |
702 | { | |
703 | struct socket *sock; | |
704 | /* special case to disable backend */ | |
705 | if (fd == -1) | |
706 | return NULL; | |
707 | sock = get_raw_socket(fd); | |
708 | if (!IS_ERR(sock)) | |
709 | return sock; | |
501c774c | 710 | sock = get_tap_socket(fd); |
3a4d5c94 MT |
711 | if (!IS_ERR(sock)) |
712 | return sock; | |
713 | return ERR_PTR(-ENOTSOCK); | |
714 | } | |
715 | ||
716 | static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) | |
717 | { | |
718 | struct socket *sock, *oldsock; | |
719 | struct vhost_virtqueue *vq; | |
720 | int r; | |
721 | ||
722 | mutex_lock(&n->dev.mutex); | |
723 | r = vhost_dev_check_owner(&n->dev); | |
724 | if (r) | |
725 | goto err; | |
726 | ||
727 | if (index >= VHOST_NET_VQ_MAX) { | |
728 | r = -ENOBUFS; | |
729 | goto err; | |
730 | } | |
731 | vq = n->vqs + index; | |
732 | mutex_lock(&vq->mutex); | |
733 | ||
734 | /* Verify that ring has been setup correctly. */ | |
735 | if (!vhost_vq_access_ok(vq)) { | |
736 | r = -EFAULT; | |
1dace8c8 | 737 | goto err_vq; |
3a4d5c94 MT |
738 | } |
739 | sock = get_socket(fd); | |
740 | if (IS_ERR(sock)) { | |
741 | r = PTR_ERR(sock); | |
1dace8c8 | 742 | goto err_vq; |
3a4d5c94 MT |
743 | } |
744 | ||
745 | /* start polling new socket */ | |
28457ee6 AB |
746 | oldsock = rcu_dereference_protected(vq->private_data, |
747 | lockdep_is_held(&vq->mutex)); | |
11fe8839 | 748 | if (sock != oldsock) { |
dd1f4078 JD |
749 | vhost_net_disable_vq(n, vq); |
750 | rcu_assign_pointer(vq->private_data, sock); | |
751 | vhost_net_enable_vq(n, vq); | |
752 | } | |
3a4d5c94 | 753 | |
1680e906 MT |
754 | mutex_unlock(&vq->mutex); |
755 | ||
3a4d5c94 MT |
756 | if (oldsock) { |
757 | vhost_net_flush_vq(n, index); | |
758 | fput(oldsock->file); | |
759 | } | |
1dace8c8 | 760 | |
1680e906 MT |
761 | mutex_unlock(&n->dev.mutex); |
762 | return 0; | |
763 | ||
1dace8c8 JD |
764 | err_vq: |
765 | mutex_unlock(&vq->mutex); | |
3a4d5c94 MT |
766 | err: |
767 | mutex_unlock(&n->dev.mutex); | |
768 | return r; | |
769 | } | |
770 | ||
771 | static long vhost_net_reset_owner(struct vhost_net *n) | |
772 | { | |
773 | struct socket *tx_sock = NULL; | |
774 | struct socket *rx_sock = NULL; | |
775 | long err; | |
776 | mutex_lock(&n->dev.mutex); | |
777 | err = vhost_dev_check_owner(&n->dev); | |
778 | if (err) | |
779 | goto done; | |
780 | vhost_net_stop(n, &tx_sock, &rx_sock); | |
781 | vhost_net_flush(n); | |
782 | err = vhost_dev_reset_owner(&n->dev); | |
783 | done: | |
784 | mutex_unlock(&n->dev.mutex); | |
785 | if (tx_sock) | |
786 | fput(tx_sock->file); | |
787 | if (rx_sock) | |
788 | fput(rx_sock->file); | |
789 | return err; | |
790 | } | |
791 | ||
792 | static int vhost_net_set_features(struct vhost_net *n, u64 features) | |
793 | { | |
8dd014ad | 794 | size_t vhost_hlen, sock_hlen, hdr_len; |
3a4d5c94 | 795 | int i; |
8dd014ad DS |
796 | |
797 | hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ? | |
798 | sizeof(struct virtio_net_hdr_mrg_rxbuf) : | |
799 | sizeof(struct virtio_net_hdr); | |
800 | if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) { | |
801 | /* vhost provides vnet_hdr */ | |
802 | vhost_hlen = hdr_len; | |
803 | sock_hlen = 0; | |
804 | } else { | |
805 | /* socket provides vnet_hdr */ | |
806 | vhost_hlen = 0; | |
807 | sock_hlen = hdr_len; | |
808 | } | |
3a4d5c94 MT |
809 | mutex_lock(&n->dev.mutex); |
810 | if ((features & (1 << VHOST_F_LOG_ALL)) && | |
811 | !vhost_log_access_ok(&n->dev)) { | |
812 | mutex_unlock(&n->dev.mutex); | |
813 | return -EFAULT; | |
814 | } | |
815 | n->dev.acked_features = features; | |
816 | smp_wmb(); | |
817 | for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { | |
818 | mutex_lock(&n->vqs[i].mutex); | |
8dd014ad DS |
819 | n->vqs[i].vhost_hlen = vhost_hlen; |
820 | n->vqs[i].sock_hlen = sock_hlen; | |
3a4d5c94 MT |
821 | mutex_unlock(&n->vqs[i].mutex); |
822 | } | |
823 | vhost_net_flush(n); | |
824 | mutex_unlock(&n->dev.mutex); | |
825 | return 0; | |
826 | } | |
827 | ||
828 | static long vhost_net_ioctl(struct file *f, unsigned int ioctl, | |
829 | unsigned long arg) | |
830 | { | |
831 | struct vhost_net *n = f->private_data; | |
832 | void __user *argp = (void __user *)arg; | |
833 | u64 __user *featurep = argp; | |
834 | struct vhost_vring_file backend; | |
835 | u64 features; | |
836 | int r; | |
837 | switch (ioctl) { | |
838 | case VHOST_NET_SET_BACKEND: | |
d3553a52 TY |
839 | if (copy_from_user(&backend, argp, sizeof backend)) |
840 | return -EFAULT; | |
3a4d5c94 MT |
841 | return vhost_net_set_backend(n, backend.index, backend.fd); |
842 | case VHOST_GET_FEATURES: | |
843 | features = VHOST_FEATURES; | |
d3553a52 TY |
844 | if (copy_to_user(featurep, &features, sizeof features)) |
845 | return -EFAULT; | |
846 | return 0; | |
3a4d5c94 | 847 | case VHOST_SET_FEATURES: |
d3553a52 TY |
848 | if (copy_from_user(&features, featurep, sizeof features)) |
849 | return -EFAULT; | |
3a4d5c94 MT |
850 | if (features & ~VHOST_FEATURES) |
851 | return -EOPNOTSUPP; | |
852 | return vhost_net_set_features(n, features); | |
853 | case VHOST_RESET_OWNER: | |
854 | return vhost_net_reset_owner(n); | |
855 | default: | |
856 | mutex_lock(&n->dev.mutex); | |
857 | r = vhost_dev_ioctl(&n->dev, ioctl, arg); | |
858 | vhost_net_flush(n); | |
859 | mutex_unlock(&n->dev.mutex); | |
860 | return r; | |
861 | } | |
862 | } | |
863 | ||
864 | #ifdef CONFIG_COMPAT | |
865 | static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl, | |
866 | unsigned long arg) | |
867 | { | |
868 | return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg)); | |
869 | } | |
870 | #endif | |
871 | ||
373a83a6 | 872 | static const struct file_operations vhost_net_fops = { |
3a4d5c94 MT |
873 | .owner = THIS_MODULE, |
874 | .release = vhost_net_release, | |
875 | .unlocked_ioctl = vhost_net_ioctl, | |
876 | #ifdef CONFIG_COMPAT | |
877 | .compat_ioctl = vhost_net_compat_ioctl, | |
878 | #endif | |
879 | .open = vhost_net_open, | |
6038f373 | 880 | .llseek = noop_llseek, |
3a4d5c94 MT |
881 | }; |
882 | ||
883 | static struct miscdevice vhost_net_misc = { | |
79907d89 | 884 | MISC_DYNAMIC_MINOR, |
3a4d5c94 MT |
885 | "vhost-net", |
886 | &vhost_net_fops, | |
887 | }; | |
888 | ||
a8d3782f | 889 | static int vhost_net_init(void) |
3a4d5c94 | 890 | { |
c23f3445 | 891 | return misc_register(&vhost_net_misc); |
3a4d5c94 MT |
892 | } |
893 | module_init(vhost_net_init); | |
894 | ||
a8d3782f | 895 | static void vhost_net_exit(void) |
3a4d5c94 MT |
896 | { |
897 | misc_deregister(&vhost_net_misc); | |
3a4d5c94 MT |
898 | } |
899 | module_exit(vhost_net_exit); | |
900 | ||
901 | MODULE_VERSION("0.0.1"); | |
902 | MODULE_LICENSE("GPL v2"); | |
903 | MODULE_AUTHOR("Michael S. Tsirkin"); | |
904 | MODULE_DESCRIPTION("Host kernel accelerator for virtio net"); |