Commit | Line | Data |
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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> | |
3a4d5c94 MT |
13 | #include <linux/miscdevice.h> |
14 | #include <linux/module.h> | |
bab632d6 | 15 | #include <linux/moduleparam.h> |
3a4d5c94 MT |
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 | ||
bab632d6 MT |
32 | static int experimental_zcopytx; |
33 | module_param(experimental_zcopytx, int, 0444); | |
34 | MODULE_PARM_DESC(experimental_zcopytx, "Enable Experimental Zero Copy TX"); | |
35 | ||
3a4d5c94 MT |
36 | /* Max number of bytes transferred before requeueing the job. |
37 | * Using this limit prevents one virtqueue from starving others. */ | |
38 | #define VHOST_NET_WEIGHT 0x80000 | |
39 | ||
bab632d6 MT |
40 | /* MAX number of TX used buffers for outstanding zerocopy */ |
41 | #define VHOST_MAX_PEND 128 | |
42 | #define VHOST_GOODCOPY_LEN 256 | |
43 | ||
3a4d5c94 MT |
44 | enum { |
45 | VHOST_NET_VQ_RX = 0, | |
46 | VHOST_NET_VQ_TX = 1, | |
47 | VHOST_NET_VQ_MAX = 2, | |
48 | }; | |
49 | ||
50 | enum vhost_net_poll_state { | |
51 | VHOST_NET_POLL_DISABLED = 0, | |
52 | VHOST_NET_POLL_STARTED = 1, | |
53 | VHOST_NET_POLL_STOPPED = 2, | |
54 | }; | |
55 | ||
56 | struct vhost_net { | |
57 | struct vhost_dev dev; | |
58 | struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX]; | |
59 | struct vhost_poll poll[VHOST_NET_VQ_MAX]; | |
60 | /* Tells us whether we are polling a socket for TX. | |
61 | * We only do this when socket buffer fills up. | |
62 | * Protected by tx vq lock. */ | |
63 | enum vhost_net_poll_state tx_poll_state; | |
64 | }; | |
65 | ||
bab632d6 MT |
66 | static bool vhost_sock_zcopy(struct socket *sock) |
67 | { | |
68 | return unlikely(experimental_zcopytx) && | |
69 | sock_flag(sock->sk, SOCK_ZEROCOPY); | |
70 | } | |
71 | ||
3a4d5c94 MT |
72 | /* Pop first len bytes from iovec. Return number of segments used. */ |
73 | static int move_iovec_hdr(struct iovec *from, struct iovec *to, | |
74 | size_t len, int iov_count) | |
75 | { | |
76 | int seg = 0; | |
77 | size_t size; | |
d47effe1 | 78 | |
3a4d5c94 MT |
79 | while (len && seg < iov_count) { |
80 | size = min(from->iov_len, len); | |
81 | to->iov_base = from->iov_base; | |
82 | to->iov_len = size; | |
83 | from->iov_len -= size; | |
84 | from->iov_base += size; | |
85 | len -= size; | |
86 | ++from; | |
87 | ++to; | |
88 | ++seg; | |
89 | } | |
90 | return seg; | |
91 | } | |
8dd014ad DS |
92 | /* Copy iovec entries for len bytes from iovec. */ |
93 | static void copy_iovec_hdr(const struct iovec *from, struct iovec *to, | |
94 | size_t len, int iovcount) | |
95 | { | |
96 | int seg = 0; | |
97 | size_t size; | |
d47effe1 | 98 | |
8dd014ad DS |
99 | while (len && seg < iovcount) { |
100 | size = min(from->iov_len, len); | |
101 | to->iov_base = from->iov_base; | |
102 | to->iov_len = size; | |
103 | len -= size; | |
104 | ++from; | |
105 | ++to; | |
106 | ++seg; | |
107 | } | |
108 | } | |
3a4d5c94 MT |
109 | |
110 | /* Caller must have TX VQ lock */ | |
111 | static void tx_poll_stop(struct vhost_net *net) | |
112 | { | |
113 | if (likely(net->tx_poll_state != VHOST_NET_POLL_STARTED)) | |
114 | return; | |
115 | vhost_poll_stop(net->poll + VHOST_NET_VQ_TX); | |
116 | net->tx_poll_state = VHOST_NET_POLL_STOPPED; | |
117 | } | |
118 | ||
119 | /* Caller must have TX VQ lock */ | |
120 | static void tx_poll_start(struct vhost_net *net, struct socket *sock) | |
121 | { | |
122 | if (unlikely(net->tx_poll_state != VHOST_NET_POLL_STOPPED)) | |
123 | return; | |
124 | vhost_poll_start(net->poll + VHOST_NET_VQ_TX, sock->file); | |
125 | net->tx_poll_state = VHOST_NET_POLL_STARTED; | |
126 | } | |
127 | ||
128 | /* Expects to be always run from workqueue - which acts as | |
129 | * read-size critical section for our kind of RCU. */ | |
130 | static void handle_tx(struct vhost_net *net) | |
131 | { | |
132 | struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX]; | |
d5675bd2 MT |
133 | unsigned out, in, s; |
134 | int head; | |
3a4d5c94 MT |
135 | struct msghdr msg = { |
136 | .msg_name = NULL, | |
137 | .msg_namelen = 0, | |
138 | .msg_control = NULL, | |
139 | .msg_controllen = 0, | |
140 | .msg_iov = vq->iov, | |
141 | .msg_flags = MSG_DONTWAIT, | |
142 | }; | |
143 | size_t len, total_len = 0; | |
144 | int err, wmem; | |
145 | size_t hdr_size; | |
28457ee6 | 146 | struct socket *sock; |
bab632d6 MT |
147 | struct vhost_ubuf_ref *uninitialized_var(ubufs); |
148 | bool zcopy; | |
28457ee6 | 149 | |
5e18247b | 150 | /* TODO: check that we are running from vhost_worker? */ |
11cd1a8b | 151 | sock = rcu_dereference_check(vq->private_data, 1); |
3a4d5c94 MT |
152 | if (!sock) |
153 | return; | |
154 | ||
155 | wmem = atomic_read(&sock->sk->sk_wmem_alloc); | |
39286fa4 SS |
156 | if (wmem >= sock->sk->sk_sndbuf) { |
157 | mutex_lock(&vq->mutex); | |
158 | tx_poll_start(net, sock); | |
159 | mutex_unlock(&vq->mutex); | |
3a4d5c94 | 160 | return; |
39286fa4 | 161 | } |
3a4d5c94 | 162 | |
3a4d5c94 | 163 | mutex_lock(&vq->mutex); |
8ea8cf89 | 164 | vhost_disable_notify(&net->dev, vq); |
3a4d5c94 | 165 | |
0e255572 | 166 | if (wmem < sock->sk->sk_sndbuf / 2) |
3a4d5c94 | 167 | tx_poll_stop(net); |
8dd014ad | 168 | hdr_size = vq->vhost_hlen; |
bab632d6 | 169 | zcopy = vhost_sock_zcopy(sock); |
3a4d5c94 MT |
170 | |
171 | for (;;) { | |
bab632d6 MT |
172 | /* Release DMAs done buffers first */ |
173 | if (zcopy) | |
174 | vhost_zerocopy_signal_used(vq); | |
175 | ||
3a4d5c94 MT |
176 | head = vhost_get_vq_desc(&net->dev, vq, vq->iov, |
177 | ARRAY_SIZE(vq->iov), | |
178 | &out, &in, | |
179 | NULL, NULL); | |
d5675bd2 | 180 | /* On error, stop handling until the next kick. */ |
7b3384fc | 181 | if (unlikely(head < 0)) |
d5675bd2 | 182 | break; |
3a4d5c94 MT |
183 | /* Nothing new? Wait for eventfd to tell us they refilled. */ |
184 | if (head == vq->num) { | |
9e380825 SM |
185 | int num_pends; |
186 | ||
3a4d5c94 MT |
187 | wmem = atomic_read(&sock->sk->sk_wmem_alloc); |
188 | if (wmem >= sock->sk->sk_sndbuf * 3 / 4) { | |
189 | tx_poll_start(net, sock); | |
190 | set_bit(SOCK_ASYNC_NOSPACE, &sock->flags); | |
191 | break; | |
192 | } | |
9e380825 SM |
193 | /* If more outstanding DMAs, queue the work. |
194 | * Handle upend_idx wrap around | |
195 | */ | |
196 | num_pends = likely(vq->upend_idx >= vq->done_idx) ? | |
197 | (vq->upend_idx - vq->done_idx) : | |
198 | (vq->upend_idx + UIO_MAXIOV - vq->done_idx); | |
199 | if (unlikely(num_pends > VHOST_MAX_PEND)) { | |
bab632d6 MT |
200 | tx_poll_start(net, sock); |
201 | set_bit(SOCK_ASYNC_NOSPACE, &sock->flags); | |
202 | break; | |
203 | } | |
8ea8cf89 MT |
204 | if (unlikely(vhost_enable_notify(&net->dev, vq))) { |
205 | vhost_disable_notify(&net->dev, vq); | |
3a4d5c94 MT |
206 | continue; |
207 | } | |
208 | break; | |
209 | } | |
210 | if (in) { | |
211 | vq_err(vq, "Unexpected descriptor format for TX: " | |
212 | "out %d, int %d\n", out, in); | |
213 | break; | |
214 | } | |
215 | /* Skip header. TODO: support TSO. */ | |
216 | s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, out); | |
217 | msg.msg_iovlen = out; | |
218 | len = iov_length(vq->iov, out); | |
219 | /* Sanity check */ | |
220 | if (!len) { | |
221 | vq_err(vq, "Unexpected header len for TX: " | |
222 | "%zd expected %zd\n", | |
223 | iov_length(vq->hdr, s), hdr_size); | |
224 | break; | |
225 | } | |
bab632d6 MT |
226 | /* use msg_control to pass vhost zerocopy ubuf info to skb */ |
227 | if (zcopy) { | |
228 | vq->heads[vq->upend_idx].id = head; | |
229 | if (len < VHOST_GOODCOPY_LEN) { | |
230 | /* copy don't need to wait for DMA done */ | |
231 | vq->heads[vq->upend_idx].len = | |
232 | VHOST_DMA_DONE_LEN; | |
233 | msg.msg_control = NULL; | |
234 | msg.msg_controllen = 0; | |
235 | ubufs = NULL; | |
236 | } else { | |
237 | struct ubuf_info *ubuf = &vq->ubuf_info[head]; | |
238 | ||
239 | vq->heads[vq->upend_idx].len = len; | |
240 | ubuf->callback = vhost_zerocopy_callback; | |
241 | ubuf->arg = vq->ubufs; | |
242 | ubuf->desc = vq->upend_idx; | |
243 | msg.msg_control = ubuf; | |
244 | msg.msg_controllen = sizeof(ubuf); | |
245 | ubufs = vq->ubufs; | |
246 | kref_get(&ubufs->kref); | |
247 | } | |
248 | vq->upend_idx = (vq->upend_idx + 1) % UIO_MAXIOV; | |
249 | } | |
3a4d5c94 MT |
250 | /* TODO: Check specific error and bomb out unless ENOBUFS? */ |
251 | err = sock->ops->sendmsg(NULL, sock, &msg, len); | |
252 | if (unlikely(err < 0)) { | |
bab632d6 MT |
253 | if (zcopy) { |
254 | if (ubufs) | |
255 | vhost_ubuf_put(ubufs); | |
256 | vq->upend_idx = ((unsigned)vq->upend_idx - 1) % | |
257 | UIO_MAXIOV; | |
258 | } | |
8dd014ad | 259 | vhost_discard_vq_desc(vq, 1); |
3a4d5c94 MT |
260 | tx_poll_start(net, sock); |
261 | break; | |
262 | } | |
263 | if (err != len) | |
95c0ec6a MT |
264 | pr_debug("Truncated TX packet: " |
265 | " len %d != %zd\n", err, len); | |
bab632d6 MT |
266 | if (!zcopy) |
267 | vhost_add_used_and_signal(&net->dev, vq, head, 0); | |
3a4d5c94 MT |
268 | total_len += len; |
269 | if (unlikely(total_len >= VHOST_NET_WEIGHT)) { | |
270 | vhost_poll_queue(&vq->poll); | |
271 | break; | |
272 | } | |
273 | } | |
274 | ||
275 | mutex_unlock(&vq->mutex); | |
3a4d5c94 MT |
276 | } |
277 | ||
8dd014ad DS |
278 | static int peek_head_len(struct sock *sk) |
279 | { | |
280 | struct sk_buff *head; | |
281 | int len = 0; | |
783e3988 | 282 | unsigned long flags; |
8dd014ad | 283 | |
783e3988 | 284 | spin_lock_irqsave(&sk->sk_receive_queue.lock, flags); |
8dd014ad | 285 | head = skb_peek(&sk->sk_receive_queue); |
783e3988 | 286 | if (likely(head)) |
8dd014ad | 287 | len = head->len; |
783e3988 | 288 | spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags); |
8dd014ad DS |
289 | return len; |
290 | } | |
291 | ||
292 | /* This is a multi-buffer version of vhost_get_desc, that works if | |
293 | * vq has read descriptors only. | |
294 | * @vq - the relevant virtqueue | |
295 | * @datalen - data length we'll be reading | |
296 | * @iovcount - returned count of io vectors we fill | |
297 | * @log - vhost log | |
298 | * @log_num - log offset | |
94249369 | 299 | * @quota - headcount quota, 1 for big buffer |
8dd014ad DS |
300 | * returns number of buffer heads allocated, negative on error |
301 | */ | |
302 | static int get_rx_bufs(struct vhost_virtqueue *vq, | |
303 | struct vring_used_elem *heads, | |
304 | int datalen, | |
305 | unsigned *iovcount, | |
306 | struct vhost_log *log, | |
94249369 JW |
307 | unsigned *log_num, |
308 | unsigned int quota) | |
8dd014ad DS |
309 | { |
310 | unsigned int out, in; | |
311 | int seg = 0; | |
312 | int headcount = 0; | |
313 | unsigned d; | |
314 | int r, nlogs = 0; | |
315 | ||
94249369 | 316 | while (datalen > 0 && headcount < quota) { |
e0e9b406 | 317 | if (unlikely(seg >= UIO_MAXIOV)) { |
8dd014ad DS |
318 | r = -ENOBUFS; |
319 | goto err; | |
320 | } | |
321 | d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg, | |
322 | ARRAY_SIZE(vq->iov) - seg, &out, | |
323 | &in, log, log_num); | |
324 | if (d == vq->num) { | |
325 | r = 0; | |
326 | goto err; | |
327 | } | |
328 | if (unlikely(out || in <= 0)) { | |
329 | vq_err(vq, "unexpected descriptor format for RX: " | |
330 | "out %d, in %d\n", out, in); | |
331 | r = -EINVAL; | |
332 | goto err; | |
333 | } | |
334 | if (unlikely(log)) { | |
335 | nlogs += *log_num; | |
336 | log += *log_num; | |
337 | } | |
338 | heads[headcount].id = d; | |
339 | heads[headcount].len = iov_length(vq->iov + seg, in); | |
340 | datalen -= heads[headcount].len; | |
341 | ++headcount; | |
342 | seg += in; | |
343 | } | |
344 | heads[headcount - 1].len += datalen; | |
345 | *iovcount = seg; | |
346 | if (unlikely(log)) | |
347 | *log_num = nlogs; | |
348 | return headcount; | |
349 | err: | |
350 | vhost_discard_vq_desc(vq, headcount); | |
351 | return r; | |
352 | } | |
353 | ||
3a4d5c94 MT |
354 | /* Expects to be always run from workqueue - which acts as |
355 | * read-size critical section for our kind of RCU. */ | |
94249369 | 356 | static void handle_rx(struct vhost_net *net) |
3a4d5c94 | 357 | { |
8dd014ad DS |
358 | struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX]; |
359 | unsigned uninitialized_var(in), log; | |
360 | struct vhost_log *vq_log; | |
361 | struct msghdr msg = { | |
362 | .msg_name = NULL, | |
363 | .msg_namelen = 0, | |
364 | .msg_control = NULL, /* FIXME: get and handle RX aux data. */ | |
365 | .msg_controllen = 0, | |
366 | .msg_iov = vq->iov, | |
367 | .msg_flags = MSG_DONTWAIT, | |
368 | }; | |
8dd014ad DS |
369 | struct virtio_net_hdr_mrg_rxbuf hdr = { |
370 | .hdr.flags = 0, | |
371 | .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE | |
372 | }; | |
8dd014ad | 373 | size_t total_len = 0; |
cfbdab95 | 374 | int err, headcount, mergeable; |
8dd014ad DS |
375 | size_t vhost_hlen, sock_hlen; |
376 | size_t vhost_len, sock_len; | |
5e18247b MT |
377 | /* TODO: check that we are running from vhost_worker? */ |
378 | struct socket *sock = rcu_dereference_check(vq->private_data, 1); | |
d47effe1 | 379 | |
de4d768a | 380 | if (!sock) |
8dd014ad DS |
381 | return; |
382 | ||
8dd014ad | 383 | mutex_lock(&vq->mutex); |
8ea8cf89 | 384 | vhost_disable_notify(&net->dev, vq); |
8dd014ad DS |
385 | vhost_hlen = vq->vhost_hlen; |
386 | sock_hlen = vq->sock_hlen; | |
387 | ||
388 | vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ? | |
389 | vq->log : NULL; | |
cfbdab95 | 390 | mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF); |
8dd014ad DS |
391 | |
392 | while ((sock_len = peek_head_len(sock->sk))) { | |
393 | sock_len += sock_hlen; | |
394 | vhost_len = sock_len + vhost_hlen; | |
395 | headcount = get_rx_bufs(vq, vq->heads, vhost_len, | |
94249369 JW |
396 | &in, vq_log, &log, |
397 | likely(mergeable) ? UIO_MAXIOV : 1); | |
8dd014ad DS |
398 | /* On error, stop handling until the next kick. */ |
399 | if (unlikely(headcount < 0)) | |
400 | break; | |
401 | /* OK, now we need to know about added descriptors. */ | |
402 | if (!headcount) { | |
8ea8cf89 | 403 | if (unlikely(vhost_enable_notify(&net->dev, vq))) { |
8dd014ad DS |
404 | /* They have slipped one in as we were |
405 | * doing that: check again. */ | |
8ea8cf89 | 406 | vhost_disable_notify(&net->dev, vq); |
8dd014ad DS |
407 | continue; |
408 | } | |
409 | /* Nothing new? Wait for eventfd to tell us | |
410 | * they refilled. */ | |
411 | break; | |
412 | } | |
413 | /* We don't need to be notified again. */ | |
414 | if (unlikely((vhost_hlen))) | |
415 | /* Skip header. TODO: support TSO. */ | |
416 | move_iovec_hdr(vq->iov, vq->hdr, vhost_hlen, in); | |
417 | else | |
418 | /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF: | |
a290aec8 | 419 | * needed because recvmsg can modify msg_iov. */ |
8dd014ad DS |
420 | copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in); |
421 | msg.msg_iovlen = in; | |
422 | err = sock->ops->recvmsg(NULL, sock, &msg, | |
423 | sock_len, MSG_DONTWAIT | MSG_TRUNC); | |
424 | /* Userspace might have consumed the packet meanwhile: | |
425 | * it's not supposed to do this usually, but might be hard | |
426 | * to prevent. Discard data we got (if any) and keep going. */ | |
427 | if (unlikely(err != sock_len)) { | |
428 | pr_debug("Discarded rx packet: " | |
429 | " len %d, expected %zd\n", err, sock_len); | |
430 | vhost_discard_vq_desc(vq, headcount); | |
431 | continue; | |
432 | } | |
433 | if (unlikely(vhost_hlen) && | |
434 | memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0, | |
435 | vhost_hlen)) { | |
436 | vq_err(vq, "Unable to write vnet_hdr at addr %p\n", | |
437 | vq->iov->iov_base); | |
438 | break; | |
439 | } | |
440 | /* TODO: Should check and handle checksum. */ | |
cfbdab95 | 441 | if (likely(mergeable) && |
8dd014ad DS |
442 | memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount, |
443 | offsetof(typeof(hdr), num_buffers), | |
444 | sizeof hdr.num_buffers)) { | |
445 | vq_err(vq, "Failed num_buffers write"); | |
446 | vhost_discard_vq_desc(vq, headcount); | |
447 | break; | |
448 | } | |
449 | vhost_add_used_and_signal_n(&net->dev, vq, vq->heads, | |
450 | headcount); | |
451 | if (unlikely(vq_log)) | |
452 | vhost_log_write(vq, vq_log, log, vhost_len); | |
453 | total_len += vhost_len; | |
454 | if (unlikely(total_len >= VHOST_NET_WEIGHT)) { | |
455 | vhost_poll_queue(&vq->poll); | |
456 | break; | |
457 | } | |
458 | } | |
459 | ||
460 | mutex_unlock(&vq->mutex); | |
8dd014ad DS |
461 | } |
462 | ||
c23f3445 | 463 | static void handle_tx_kick(struct vhost_work *work) |
3a4d5c94 | 464 | { |
c23f3445 TH |
465 | struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, |
466 | poll.work); | |
467 | struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev); | |
468 | ||
3a4d5c94 MT |
469 | handle_tx(net); |
470 | } | |
471 | ||
c23f3445 | 472 | static void handle_rx_kick(struct vhost_work *work) |
3a4d5c94 | 473 | { |
c23f3445 TH |
474 | struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, |
475 | poll.work); | |
476 | struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev); | |
477 | ||
3a4d5c94 MT |
478 | handle_rx(net); |
479 | } | |
480 | ||
c23f3445 | 481 | static void handle_tx_net(struct vhost_work *work) |
3a4d5c94 | 482 | { |
c23f3445 TH |
483 | struct vhost_net *net = container_of(work, struct vhost_net, |
484 | poll[VHOST_NET_VQ_TX].work); | |
3a4d5c94 MT |
485 | handle_tx(net); |
486 | } | |
487 | ||
c23f3445 | 488 | static void handle_rx_net(struct vhost_work *work) |
3a4d5c94 | 489 | { |
c23f3445 TH |
490 | struct vhost_net *net = container_of(work, struct vhost_net, |
491 | poll[VHOST_NET_VQ_RX].work); | |
3a4d5c94 MT |
492 | handle_rx(net); |
493 | } | |
494 | ||
495 | static int vhost_net_open(struct inode *inode, struct file *f) | |
496 | { | |
497 | struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL); | |
c23f3445 | 498 | struct vhost_dev *dev; |
3a4d5c94 | 499 | int r; |
c23f3445 | 500 | |
3a4d5c94 MT |
501 | if (!n) |
502 | return -ENOMEM; | |
c23f3445 TH |
503 | |
504 | dev = &n->dev; | |
3a4d5c94 MT |
505 | n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick; |
506 | n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick; | |
c23f3445 | 507 | r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX); |
3a4d5c94 MT |
508 | if (r < 0) { |
509 | kfree(n); | |
510 | return r; | |
511 | } | |
512 | ||
c23f3445 TH |
513 | vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev); |
514 | vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev); | |
3a4d5c94 MT |
515 | n->tx_poll_state = VHOST_NET_POLL_DISABLED; |
516 | ||
517 | f->private_data = n; | |
518 | ||
519 | return 0; | |
520 | } | |
521 | ||
522 | static void vhost_net_disable_vq(struct vhost_net *n, | |
523 | struct vhost_virtqueue *vq) | |
524 | { | |
525 | if (!vq->private_data) | |
526 | return; | |
527 | if (vq == n->vqs + VHOST_NET_VQ_TX) { | |
528 | tx_poll_stop(n); | |
529 | n->tx_poll_state = VHOST_NET_POLL_DISABLED; | |
530 | } else | |
531 | vhost_poll_stop(n->poll + VHOST_NET_VQ_RX); | |
532 | } | |
533 | ||
534 | static void vhost_net_enable_vq(struct vhost_net *n, | |
535 | struct vhost_virtqueue *vq) | |
536 | { | |
28457ee6 AB |
537 | struct socket *sock; |
538 | ||
539 | sock = rcu_dereference_protected(vq->private_data, | |
540 | lockdep_is_held(&vq->mutex)); | |
3a4d5c94 MT |
541 | if (!sock) |
542 | return; | |
543 | if (vq == n->vqs + VHOST_NET_VQ_TX) { | |
544 | n->tx_poll_state = VHOST_NET_POLL_STOPPED; | |
545 | tx_poll_start(n, sock); | |
546 | } else | |
547 | vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file); | |
548 | } | |
549 | ||
550 | static struct socket *vhost_net_stop_vq(struct vhost_net *n, | |
551 | struct vhost_virtqueue *vq) | |
552 | { | |
553 | struct socket *sock; | |
554 | ||
555 | mutex_lock(&vq->mutex); | |
28457ee6 AB |
556 | sock = rcu_dereference_protected(vq->private_data, |
557 | lockdep_is_held(&vq->mutex)); | |
3a4d5c94 MT |
558 | vhost_net_disable_vq(n, vq); |
559 | rcu_assign_pointer(vq->private_data, NULL); | |
560 | mutex_unlock(&vq->mutex); | |
561 | return sock; | |
562 | } | |
563 | ||
564 | static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock, | |
565 | struct socket **rx_sock) | |
566 | { | |
567 | *tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX); | |
568 | *rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX); | |
569 | } | |
570 | ||
571 | static void vhost_net_flush_vq(struct vhost_net *n, int index) | |
572 | { | |
573 | vhost_poll_flush(n->poll + index); | |
574 | vhost_poll_flush(&n->dev.vqs[index].poll); | |
575 | } | |
576 | ||
577 | static void vhost_net_flush(struct vhost_net *n) | |
578 | { | |
579 | vhost_net_flush_vq(n, VHOST_NET_VQ_TX); | |
580 | vhost_net_flush_vq(n, VHOST_NET_VQ_RX); | |
581 | } | |
582 | ||
583 | static int vhost_net_release(struct inode *inode, struct file *f) | |
584 | { | |
585 | struct vhost_net *n = f->private_data; | |
586 | struct socket *tx_sock; | |
587 | struct socket *rx_sock; | |
588 | ||
589 | vhost_net_stop(n, &tx_sock, &rx_sock); | |
590 | vhost_net_flush(n); | |
ea5d4046 | 591 | vhost_dev_cleanup(&n->dev, false); |
3a4d5c94 MT |
592 | if (tx_sock) |
593 | fput(tx_sock->file); | |
594 | if (rx_sock) | |
595 | fput(rx_sock->file); | |
596 | /* We do an extra flush before freeing memory, | |
597 | * since jobs can re-queue themselves. */ | |
598 | vhost_net_flush(n); | |
599 | kfree(n); | |
600 | return 0; | |
601 | } | |
602 | ||
603 | static struct socket *get_raw_socket(int fd) | |
604 | { | |
605 | struct { | |
606 | struct sockaddr_ll sa; | |
607 | char buf[MAX_ADDR_LEN]; | |
608 | } uaddr; | |
609 | int uaddr_len = sizeof uaddr, r; | |
610 | struct socket *sock = sockfd_lookup(fd, &r); | |
d47effe1 | 611 | |
3a4d5c94 MT |
612 | if (!sock) |
613 | return ERR_PTR(-ENOTSOCK); | |
614 | ||
615 | /* Parameter checking */ | |
616 | if (sock->sk->sk_type != SOCK_RAW) { | |
617 | r = -ESOCKTNOSUPPORT; | |
618 | goto err; | |
619 | } | |
620 | ||
621 | r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa, | |
622 | &uaddr_len, 0); | |
623 | if (r) | |
624 | goto err; | |
625 | ||
626 | if (uaddr.sa.sll_family != AF_PACKET) { | |
627 | r = -EPFNOSUPPORT; | |
628 | goto err; | |
629 | } | |
630 | return sock; | |
631 | err: | |
632 | fput(sock->file); | |
633 | return ERR_PTR(r); | |
634 | } | |
635 | ||
501c774c | 636 | static struct socket *get_tap_socket(int fd) |
3a4d5c94 MT |
637 | { |
638 | struct file *file = fget(fd); | |
639 | struct socket *sock; | |
d47effe1 | 640 | |
3a4d5c94 MT |
641 | if (!file) |
642 | return ERR_PTR(-EBADF); | |
643 | sock = tun_get_socket(file); | |
501c774c AB |
644 | if (!IS_ERR(sock)) |
645 | return sock; | |
646 | sock = macvtap_get_socket(file); | |
3a4d5c94 MT |
647 | if (IS_ERR(sock)) |
648 | fput(file); | |
649 | return sock; | |
650 | } | |
651 | ||
652 | static struct socket *get_socket(int fd) | |
653 | { | |
654 | struct socket *sock; | |
d47effe1 | 655 | |
3a4d5c94 MT |
656 | /* special case to disable backend */ |
657 | if (fd == -1) | |
658 | return NULL; | |
659 | sock = get_raw_socket(fd); | |
660 | if (!IS_ERR(sock)) | |
661 | return sock; | |
501c774c | 662 | sock = get_tap_socket(fd); |
3a4d5c94 MT |
663 | if (!IS_ERR(sock)) |
664 | return sock; | |
665 | return ERR_PTR(-ENOTSOCK); | |
666 | } | |
667 | ||
668 | static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) | |
669 | { | |
670 | struct socket *sock, *oldsock; | |
671 | struct vhost_virtqueue *vq; | |
bab632d6 | 672 | struct vhost_ubuf_ref *ubufs, *oldubufs = NULL; |
3a4d5c94 MT |
673 | int r; |
674 | ||
675 | mutex_lock(&n->dev.mutex); | |
676 | r = vhost_dev_check_owner(&n->dev); | |
677 | if (r) | |
678 | goto err; | |
679 | ||
680 | if (index >= VHOST_NET_VQ_MAX) { | |
681 | r = -ENOBUFS; | |
682 | goto err; | |
683 | } | |
684 | vq = n->vqs + index; | |
685 | mutex_lock(&vq->mutex); | |
686 | ||
687 | /* Verify that ring has been setup correctly. */ | |
688 | if (!vhost_vq_access_ok(vq)) { | |
689 | r = -EFAULT; | |
1dace8c8 | 690 | goto err_vq; |
3a4d5c94 MT |
691 | } |
692 | sock = get_socket(fd); | |
693 | if (IS_ERR(sock)) { | |
694 | r = PTR_ERR(sock); | |
1dace8c8 | 695 | goto err_vq; |
3a4d5c94 MT |
696 | } |
697 | ||
698 | /* start polling new socket */ | |
28457ee6 AB |
699 | oldsock = rcu_dereference_protected(vq->private_data, |
700 | lockdep_is_held(&vq->mutex)); | |
11fe8839 | 701 | if (sock != oldsock) { |
bab632d6 MT |
702 | ubufs = vhost_ubuf_alloc(vq, sock && vhost_sock_zcopy(sock)); |
703 | if (IS_ERR(ubufs)) { | |
704 | r = PTR_ERR(ubufs); | |
705 | goto err_ubufs; | |
706 | } | |
707 | oldubufs = vq->ubufs; | |
708 | vq->ubufs = ubufs; | |
d47effe1 KK |
709 | vhost_net_disable_vq(n, vq); |
710 | rcu_assign_pointer(vq->private_data, sock); | |
711 | vhost_net_enable_vq(n, vq); | |
f59281da JW |
712 | |
713 | r = vhost_init_used(vq); | |
714 | if (r) | |
715 | goto err_vq; | |
dd1f4078 | 716 | } |
3a4d5c94 | 717 | |
1680e906 MT |
718 | mutex_unlock(&vq->mutex); |
719 | ||
c047e5f3 | 720 | if (oldubufs) { |
bab632d6 | 721 | vhost_ubuf_put_and_wait(oldubufs); |
c047e5f3 MT |
722 | mutex_lock(&vq->mutex); |
723 | vhost_zerocopy_signal_used(vq); | |
724 | mutex_unlock(&vq->mutex); | |
725 | } | |
bab632d6 | 726 | |
3a4d5c94 MT |
727 | if (oldsock) { |
728 | vhost_net_flush_vq(n, index); | |
729 | fput(oldsock->file); | |
730 | } | |
1dace8c8 | 731 | |
1680e906 MT |
732 | mutex_unlock(&n->dev.mutex); |
733 | return 0; | |
734 | ||
bab632d6 MT |
735 | err_ubufs: |
736 | fput(sock->file); | |
1dace8c8 JD |
737 | err_vq: |
738 | mutex_unlock(&vq->mutex); | |
3a4d5c94 MT |
739 | err: |
740 | mutex_unlock(&n->dev.mutex); | |
741 | return r; | |
742 | } | |
743 | ||
744 | static long vhost_net_reset_owner(struct vhost_net *n) | |
745 | { | |
746 | struct socket *tx_sock = NULL; | |
747 | struct socket *rx_sock = NULL; | |
748 | long err; | |
d47effe1 | 749 | |
3a4d5c94 MT |
750 | mutex_lock(&n->dev.mutex); |
751 | err = vhost_dev_check_owner(&n->dev); | |
752 | if (err) | |
753 | goto done; | |
754 | vhost_net_stop(n, &tx_sock, &rx_sock); | |
755 | vhost_net_flush(n); | |
756 | err = vhost_dev_reset_owner(&n->dev); | |
757 | done: | |
758 | mutex_unlock(&n->dev.mutex); | |
759 | if (tx_sock) | |
760 | fput(tx_sock->file); | |
761 | if (rx_sock) | |
762 | fput(rx_sock->file); | |
763 | return err; | |
764 | } | |
765 | ||
766 | static int vhost_net_set_features(struct vhost_net *n, u64 features) | |
767 | { | |
8dd014ad | 768 | size_t vhost_hlen, sock_hlen, hdr_len; |
3a4d5c94 | 769 | int i; |
8dd014ad DS |
770 | |
771 | hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ? | |
772 | sizeof(struct virtio_net_hdr_mrg_rxbuf) : | |
773 | sizeof(struct virtio_net_hdr); | |
774 | if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) { | |
775 | /* vhost provides vnet_hdr */ | |
776 | vhost_hlen = hdr_len; | |
777 | sock_hlen = 0; | |
778 | } else { | |
779 | /* socket provides vnet_hdr */ | |
780 | vhost_hlen = 0; | |
781 | sock_hlen = hdr_len; | |
782 | } | |
3a4d5c94 MT |
783 | mutex_lock(&n->dev.mutex); |
784 | if ((features & (1 << VHOST_F_LOG_ALL)) && | |
785 | !vhost_log_access_ok(&n->dev)) { | |
786 | mutex_unlock(&n->dev.mutex); | |
787 | return -EFAULT; | |
788 | } | |
789 | n->dev.acked_features = features; | |
790 | smp_wmb(); | |
791 | for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { | |
792 | mutex_lock(&n->vqs[i].mutex); | |
8dd014ad DS |
793 | n->vqs[i].vhost_hlen = vhost_hlen; |
794 | n->vqs[i].sock_hlen = sock_hlen; | |
3a4d5c94 MT |
795 | mutex_unlock(&n->vqs[i].mutex); |
796 | } | |
797 | vhost_net_flush(n); | |
798 | mutex_unlock(&n->dev.mutex); | |
799 | return 0; | |
800 | } | |
801 | ||
802 | static long vhost_net_ioctl(struct file *f, unsigned int ioctl, | |
803 | unsigned long arg) | |
804 | { | |
805 | struct vhost_net *n = f->private_data; | |
806 | void __user *argp = (void __user *)arg; | |
807 | u64 __user *featurep = argp; | |
808 | struct vhost_vring_file backend; | |
809 | u64 features; | |
810 | int r; | |
d47effe1 | 811 | |
3a4d5c94 MT |
812 | switch (ioctl) { |
813 | case VHOST_NET_SET_BACKEND: | |
d3553a52 TY |
814 | if (copy_from_user(&backend, argp, sizeof backend)) |
815 | return -EFAULT; | |
3a4d5c94 MT |
816 | return vhost_net_set_backend(n, backend.index, backend.fd); |
817 | case VHOST_GET_FEATURES: | |
818 | features = VHOST_FEATURES; | |
d3553a52 TY |
819 | if (copy_to_user(featurep, &features, sizeof features)) |
820 | return -EFAULT; | |
821 | return 0; | |
3a4d5c94 | 822 | case VHOST_SET_FEATURES: |
d3553a52 TY |
823 | if (copy_from_user(&features, featurep, sizeof features)) |
824 | return -EFAULT; | |
3a4d5c94 MT |
825 | if (features & ~VHOST_FEATURES) |
826 | return -EOPNOTSUPP; | |
827 | return vhost_net_set_features(n, features); | |
828 | case VHOST_RESET_OWNER: | |
829 | return vhost_net_reset_owner(n); | |
830 | default: | |
831 | mutex_lock(&n->dev.mutex); | |
832 | r = vhost_dev_ioctl(&n->dev, ioctl, arg); | |
833 | vhost_net_flush(n); | |
834 | mutex_unlock(&n->dev.mutex); | |
835 | return r; | |
836 | } | |
837 | } | |
838 | ||
839 | #ifdef CONFIG_COMPAT | |
840 | static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl, | |
841 | unsigned long arg) | |
842 | { | |
843 | return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg)); | |
844 | } | |
845 | #endif | |
846 | ||
373a83a6 | 847 | static const struct file_operations vhost_net_fops = { |
3a4d5c94 MT |
848 | .owner = THIS_MODULE, |
849 | .release = vhost_net_release, | |
850 | .unlocked_ioctl = vhost_net_ioctl, | |
851 | #ifdef CONFIG_COMPAT | |
852 | .compat_ioctl = vhost_net_compat_ioctl, | |
853 | #endif | |
854 | .open = vhost_net_open, | |
6038f373 | 855 | .llseek = noop_llseek, |
3a4d5c94 MT |
856 | }; |
857 | ||
858 | static struct miscdevice vhost_net_misc = { | |
7c7c7f01 | 859 | .minor = VHOST_NET_MINOR, |
860 | .name = "vhost-net", | |
861 | .fops = &vhost_net_fops, | |
3a4d5c94 MT |
862 | }; |
863 | ||
a8d3782f | 864 | static int vhost_net_init(void) |
3a4d5c94 | 865 | { |
bab632d6 MT |
866 | if (experimental_zcopytx) |
867 | vhost_enable_zcopy(VHOST_NET_VQ_TX); | |
c23f3445 | 868 | return misc_register(&vhost_net_misc); |
3a4d5c94 MT |
869 | } |
870 | module_init(vhost_net_init); | |
871 | ||
a8d3782f | 872 | static void vhost_net_exit(void) |
3a4d5c94 MT |
873 | { |
874 | misc_deregister(&vhost_net_misc); | |
3a4d5c94 MT |
875 | } |
876 | module_exit(vhost_net_exit); | |
877 | ||
878 | MODULE_VERSION("0.0.1"); | |
879 | MODULE_LICENSE("GPL v2"); | |
880 | MODULE_AUTHOR("Michael S. Tsirkin"); | |
881 | MODULE_DESCRIPTION("Host kernel accelerator for virtio net"); | |
7c7c7f01 | 882 | MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR); |
883 | MODULE_ALIAS("devname:vhost-net"); |