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