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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> |
c53cff5e | 27 | #include <linux/if_vlan.h> |
3a4d5c94 MT |
28 | |
29 | #include <net/sock.h> | |
30 | ||
31 | #include "vhost.h" | |
32 | ||
bab632d6 MT |
33 | static int experimental_zcopytx; |
34 | module_param(experimental_zcopytx, int, 0444); | |
35 | MODULE_PARM_DESC(experimental_zcopytx, "Enable Experimental Zero Copy TX"); | |
36 | ||
3a4d5c94 MT |
37 | /* Max number of bytes transferred before requeueing the job. |
38 | * Using this limit prevents one virtqueue from starving others. */ | |
39 | #define VHOST_NET_WEIGHT 0x80000 | |
40 | ||
bab632d6 MT |
41 | /* MAX number of TX used buffers for outstanding zerocopy */ |
42 | #define VHOST_MAX_PEND 128 | |
43 | #define VHOST_GOODCOPY_LEN 256 | |
44 | ||
3a4d5c94 MT |
45 | enum { |
46 | VHOST_NET_VQ_RX = 0, | |
47 | VHOST_NET_VQ_TX = 1, | |
48 | VHOST_NET_VQ_MAX = 2, | |
49 | }; | |
50 | ||
51 | enum vhost_net_poll_state { | |
52 | VHOST_NET_POLL_DISABLED = 0, | |
53 | VHOST_NET_POLL_STARTED = 1, | |
54 | VHOST_NET_POLL_STOPPED = 2, | |
55 | }; | |
56 | ||
57 | struct vhost_net { | |
58 | struct vhost_dev dev; | |
59 | struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX]; | |
60 | struct vhost_poll poll[VHOST_NET_VQ_MAX]; | |
61 | /* Tells us whether we are polling a socket for TX. | |
62 | * We only do this when socket buffer fills up. | |
63 | * Protected by tx vq lock. */ | |
64 | enum vhost_net_poll_state tx_poll_state; | |
65 | }; | |
66 | ||
bab632d6 MT |
67 | static bool vhost_sock_zcopy(struct socket *sock) |
68 | { | |
69 | return unlikely(experimental_zcopytx) && | |
70 | sock_flag(sock->sk, SOCK_ZEROCOPY); | |
71 | } | |
72 | ||
3a4d5c94 MT |
73 | /* Pop first len bytes from iovec. Return number of segments used. */ |
74 | static int move_iovec_hdr(struct iovec *from, struct iovec *to, | |
75 | size_t len, int iov_count) | |
76 | { | |
77 | int seg = 0; | |
78 | size_t size; | |
d47effe1 | 79 | |
3a4d5c94 MT |
80 | while (len && seg < iov_count) { |
81 | size = min(from->iov_len, len); | |
82 | to->iov_base = from->iov_base; | |
83 | to->iov_len = size; | |
84 | from->iov_len -= size; | |
85 | from->iov_base += size; | |
86 | len -= size; | |
87 | ++from; | |
88 | ++to; | |
89 | ++seg; | |
90 | } | |
91 | return seg; | |
92 | } | |
8dd014ad DS |
93 | /* Copy iovec entries for len bytes from iovec. */ |
94 | static void copy_iovec_hdr(const struct iovec *from, struct iovec *to, | |
95 | size_t len, int iovcount) | |
96 | { | |
97 | int seg = 0; | |
98 | size_t size; | |
d47effe1 | 99 | |
8dd014ad DS |
100 | while (len && seg < iovcount) { |
101 | size = min(from->iov_len, len); | |
102 | to->iov_base = from->iov_base; | |
103 | to->iov_len = size; | |
104 | len -= size; | |
105 | ++from; | |
106 | ++to; | |
107 | ++seg; | |
108 | } | |
109 | } | |
3a4d5c94 MT |
110 | |
111 | /* Caller must have TX VQ lock */ | |
112 | static void tx_poll_stop(struct vhost_net *net) | |
113 | { | |
114 | if (likely(net->tx_poll_state != VHOST_NET_POLL_STARTED)) | |
115 | return; | |
116 | vhost_poll_stop(net->poll + VHOST_NET_VQ_TX); | |
117 | net->tx_poll_state = VHOST_NET_POLL_STOPPED; | |
118 | } | |
119 | ||
120 | /* Caller must have TX VQ lock */ | |
121 | static void tx_poll_start(struct vhost_net *net, struct socket *sock) | |
122 | { | |
123 | if (unlikely(net->tx_poll_state != VHOST_NET_POLL_STOPPED)) | |
124 | return; | |
125 | vhost_poll_start(net->poll + VHOST_NET_VQ_TX, sock->file); | |
126 | net->tx_poll_state = VHOST_NET_POLL_STARTED; | |
127 | } | |
128 | ||
129 | /* Expects to be always run from workqueue - which acts as | |
130 | * read-size critical section for our kind of RCU. */ | |
131 | static void handle_tx(struct vhost_net *net) | |
132 | { | |
133 | struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX]; | |
d5675bd2 MT |
134 | unsigned out, in, s; |
135 | int head; | |
3a4d5c94 MT |
136 | struct msghdr msg = { |
137 | .msg_name = NULL, | |
138 | .msg_namelen = 0, | |
139 | .msg_control = NULL, | |
140 | .msg_controllen = 0, | |
141 | .msg_iov = vq->iov, | |
142 | .msg_flags = MSG_DONTWAIT, | |
143 | }; | |
144 | size_t len, total_len = 0; | |
145 | int err, wmem; | |
146 | size_t hdr_size; | |
28457ee6 | 147 | struct socket *sock; |
bab632d6 MT |
148 | struct vhost_ubuf_ref *uninitialized_var(ubufs); |
149 | bool zcopy; | |
28457ee6 | 150 | |
5e18247b | 151 | /* TODO: check that we are running from vhost_worker? */ |
11cd1a8b | 152 | sock = rcu_dereference_check(vq->private_data, 1); |
3a4d5c94 MT |
153 | if (!sock) |
154 | return; | |
155 | ||
156 | wmem = atomic_read(&sock->sk->sk_wmem_alloc); | |
39286fa4 SS |
157 | if (wmem >= sock->sk->sk_sndbuf) { |
158 | mutex_lock(&vq->mutex); | |
159 | tx_poll_start(net, sock); | |
160 | mutex_unlock(&vq->mutex); | |
3a4d5c94 | 161 | return; |
39286fa4 | 162 | } |
3a4d5c94 | 163 | |
3a4d5c94 | 164 | mutex_lock(&vq->mutex); |
8ea8cf89 | 165 | vhost_disable_notify(&net->dev, vq); |
3a4d5c94 | 166 | |
0e255572 | 167 | if (wmem < sock->sk->sk_sndbuf / 2) |
3a4d5c94 | 168 | tx_poll_stop(net); |
8dd014ad | 169 | hdr_size = vq->vhost_hlen; |
bab632d6 | 170 | zcopy = vhost_sock_zcopy(sock); |
3a4d5c94 MT |
171 | |
172 | for (;;) { | |
bab632d6 MT |
173 | /* Release DMAs done buffers first */ |
174 | if (zcopy) | |
175 | vhost_zerocopy_signal_used(vq); | |
176 | ||
3a4d5c94 MT |
177 | head = vhost_get_vq_desc(&net->dev, vq, vq->iov, |
178 | ARRAY_SIZE(vq->iov), | |
179 | &out, &in, | |
180 | NULL, NULL); | |
d5675bd2 | 181 | /* On error, stop handling until the next kick. */ |
7b3384fc | 182 | if (unlikely(head < 0)) |
d5675bd2 | 183 | break; |
3a4d5c94 MT |
184 | /* Nothing new? Wait for eventfd to tell us they refilled. */ |
185 | if (head == vq->num) { | |
9e380825 SM |
186 | int num_pends; |
187 | ||
3a4d5c94 MT |
188 | wmem = atomic_read(&sock->sk->sk_wmem_alloc); |
189 | if (wmem >= sock->sk->sk_sndbuf * 3 / 4) { | |
190 | tx_poll_start(net, sock); | |
191 | set_bit(SOCK_ASYNC_NOSPACE, &sock->flags); | |
192 | break; | |
193 | } | |
9e380825 SM |
194 | /* If more outstanding DMAs, queue the work. |
195 | * Handle upend_idx wrap around | |
196 | */ | |
197 | num_pends = likely(vq->upend_idx >= vq->done_idx) ? | |
198 | (vq->upend_idx - vq->done_idx) : | |
199 | (vq->upend_idx + UIO_MAXIOV - vq->done_idx); | |
200 | if (unlikely(num_pends > VHOST_MAX_PEND)) { | |
bab632d6 MT |
201 | tx_poll_start(net, sock); |
202 | set_bit(SOCK_ASYNC_NOSPACE, &sock->flags); | |
203 | break; | |
204 | } | |
8ea8cf89 MT |
205 | if (unlikely(vhost_enable_notify(&net->dev, vq))) { |
206 | vhost_disable_notify(&net->dev, vq); | |
3a4d5c94 MT |
207 | continue; |
208 | } | |
209 | break; | |
210 | } | |
211 | if (in) { | |
212 | vq_err(vq, "Unexpected descriptor format for TX: " | |
213 | "out %d, int %d\n", out, in); | |
214 | break; | |
215 | } | |
216 | /* Skip header. TODO: support TSO. */ | |
217 | s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, out); | |
218 | msg.msg_iovlen = out; | |
219 | len = iov_length(vq->iov, out); | |
220 | /* Sanity check */ | |
221 | if (!len) { | |
222 | vq_err(vq, "Unexpected header len for TX: " | |
223 | "%zd expected %zd\n", | |
224 | iov_length(vq->hdr, s), hdr_size); | |
225 | break; | |
226 | } | |
bab632d6 MT |
227 | /* use msg_control to pass vhost zerocopy ubuf info to skb */ |
228 | if (zcopy) { | |
229 | vq->heads[vq->upend_idx].id = head; | |
230 | if (len < VHOST_GOODCOPY_LEN) { | |
231 | /* copy don't need to wait for DMA done */ | |
232 | vq->heads[vq->upend_idx].len = | |
233 | VHOST_DMA_DONE_LEN; | |
234 | msg.msg_control = NULL; | |
235 | msg.msg_controllen = 0; | |
236 | ubufs = NULL; | |
237 | } else { | |
238 | struct ubuf_info *ubuf = &vq->ubuf_info[head]; | |
239 | ||
240 | vq->heads[vq->upend_idx].len = len; | |
241 | ubuf->callback = vhost_zerocopy_callback; | |
ca8f4fb2 | 242 | ubuf->ctx = vq->ubufs; |
bab632d6 MT |
243 | ubuf->desc = vq->upend_idx; |
244 | msg.msg_control = ubuf; | |
245 | msg.msg_controllen = sizeof(ubuf); | |
246 | ubufs = vq->ubufs; | |
247 | kref_get(&ubufs->kref); | |
248 | } | |
249 | vq->upend_idx = (vq->upend_idx + 1) % UIO_MAXIOV; | |
250 | } | |
3a4d5c94 MT |
251 | /* TODO: Check specific error and bomb out unless ENOBUFS? */ |
252 | err = sock->ops->sendmsg(NULL, sock, &msg, len); | |
253 | if (unlikely(err < 0)) { | |
bab632d6 MT |
254 | if (zcopy) { |
255 | if (ubufs) | |
256 | vhost_ubuf_put(ubufs); | |
257 | vq->upend_idx = ((unsigned)vq->upend_idx - 1) % | |
258 | UIO_MAXIOV; | |
259 | } | |
8dd014ad | 260 | vhost_discard_vq_desc(vq, 1); |
3a4d5c94 MT |
261 | tx_poll_start(net, sock); |
262 | break; | |
263 | } | |
264 | if (err != len) | |
95c0ec6a MT |
265 | pr_debug("Truncated TX packet: " |
266 | " len %d != %zd\n", err, len); | |
bab632d6 MT |
267 | if (!zcopy) |
268 | vhost_add_used_and_signal(&net->dev, vq, head, 0); | |
3a4d5c94 MT |
269 | total_len += len; |
270 | if (unlikely(total_len >= VHOST_NET_WEIGHT)) { | |
271 | vhost_poll_queue(&vq->poll); | |
272 | break; | |
273 | } | |
274 | } | |
275 | ||
276 | mutex_unlock(&vq->mutex); | |
3a4d5c94 MT |
277 | } |
278 | ||
8dd014ad DS |
279 | static int peek_head_len(struct sock *sk) |
280 | { | |
281 | struct sk_buff *head; | |
282 | int len = 0; | |
783e3988 | 283 | unsigned long flags; |
8dd014ad | 284 | |
783e3988 | 285 | spin_lock_irqsave(&sk->sk_receive_queue.lock, flags); |
8dd014ad | 286 | head = skb_peek(&sk->sk_receive_queue); |
c53cff5e | 287 | if (likely(head)) { |
8dd014ad | 288 | len = head->len; |
c53cff5e BG |
289 | if (vlan_tx_tag_present(head)) |
290 | len += VLAN_HLEN; | |
291 | } | |
292 | ||
783e3988 | 293 | spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags); |
8dd014ad DS |
294 | return len; |
295 | } | |
296 | ||
297 | /* This is a multi-buffer version of vhost_get_desc, that works if | |
298 | * vq has read descriptors only. | |
299 | * @vq - the relevant virtqueue | |
300 | * @datalen - data length we'll be reading | |
301 | * @iovcount - returned count of io vectors we fill | |
302 | * @log - vhost log | |
303 | * @log_num - log offset | |
94249369 | 304 | * @quota - headcount quota, 1 for big buffer |
8dd014ad DS |
305 | * returns number of buffer heads allocated, negative on error |
306 | */ | |
307 | static int get_rx_bufs(struct vhost_virtqueue *vq, | |
308 | struct vring_used_elem *heads, | |
309 | int datalen, | |
310 | unsigned *iovcount, | |
311 | struct vhost_log *log, | |
94249369 JW |
312 | unsigned *log_num, |
313 | unsigned int quota) | |
8dd014ad DS |
314 | { |
315 | unsigned int out, in; | |
316 | int seg = 0; | |
317 | int headcount = 0; | |
318 | unsigned d; | |
319 | int r, nlogs = 0; | |
320 | ||
94249369 | 321 | while (datalen > 0 && headcount < quota) { |
e0e9b406 | 322 | if (unlikely(seg >= UIO_MAXIOV)) { |
8dd014ad DS |
323 | r = -ENOBUFS; |
324 | goto err; | |
325 | } | |
326 | d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg, | |
327 | ARRAY_SIZE(vq->iov) - seg, &out, | |
328 | &in, log, log_num); | |
329 | if (d == vq->num) { | |
330 | r = 0; | |
331 | goto err; | |
332 | } | |
333 | if (unlikely(out || in <= 0)) { | |
334 | vq_err(vq, "unexpected descriptor format for RX: " | |
335 | "out %d, in %d\n", out, in); | |
336 | r = -EINVAL; | |
337 | goto err; | |
338 | } | |
339 | if (unlikely(log)) { | |
340 | nlogs += *log_num; | |
341 | log += *log_num; | |
342 | } | |
343 | heads[headcount].id = d; | |
344 | heads[headcount].len = iov_length(vq->iov + seg, in); | |
345 | datalen -= heads[headcount].len; | |
346 | ++headcount; | |
347 | seg += in; | |
348 | } | |
349 | heads[headcount - 1].len += datalen; | |
350 | *iovcount = seg; | |
351 | if (unlikely(log)) | |
352 | *log_num = nlogs; | |
353 | return headcount; | |
354 | err: | |
355 | vhost_discard_vq_desc(vq, headcount); | |
356 | return r; | |
357 | } | |
358 | ||
3a4d5c94 MT |
359 | /* Expects to be always run from workqueue - which acts as |
360 | * read-size critical section for our kind of RCU. */ | |
94249369 | 361 | static void handle_rx(struct vhost_net *net) |
3a4d5c94 | 362 | { |
8dd014ad DS |
363 | struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX]; |
364 | unsigned uninitialized_var(in), log; | |
365 | struct vhost_log *vq_log; | |
366 | struct msghdr msg = { | |
367 | .msg_name = NULL, | |
368 | .msg_namelen = 0, | |
369 | .msg_control = NULL, /* FIXME: get and handle RX aux data. */ | |
370 | .msg_controllen = 0, | |
371 | .msg_iov = vq->iov, | |
372 | .msg_flags = MSG_DONTWAIT, | |
373 | }; | |
8dd014ad DS |
374 | struct virtio_net_hdr_mrg_rxbuf hdr = { |
375 | .hdr.flags = 0, | |
376 | .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE | |
377 | }; | |
8dd014ad | 378 | size_t total_len = 0; |
cfbdab95 | 379 | int err, headcount, mergeable; |
8dd014ad DS |
380 | size_t vhost_hlen, sock_hlen; |
381 | size_t vhost_len, sock_len; | |
5e18247b MT |
382 | /* TODO: check that we are running from vhost_worker? */ |
383 | struct socket *sock = rcu_dereference_check(vq->private_data, 1); | |
d47effe1 | 384 | |
de4d768a | 385 | if (!sock) |
8dd014ad DS |
386 | return; |
387 | ||
8dd014ad | 388 | mutex_lock(&vq->mutex); |
8ea8cf89 | 389 | vhost_disable_notify(&net->dev, vq); |
8dd014ad DS |
390 | vhost_hlen = vq->vhost_hlen; |
391 | sock_hlen = vq->sock_hlen; | |
392 | ||
393 | vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ? | |
394 | vq->log : NULL; | |
cfbdab95 | 395 | mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF); |
8dd014ad DS |
396 | |
397 | while ((sock_len = peek_head_len(sock->sk))) { | |
398 | sock_len += sock_hlen; | |
399 | vhost_len = sock_len + vhost_hlen; | |
400 | headcount = get_rx_bufs(vq, vq->heads, vhost_len, | |
94249369 JW |
401 | &in, vq_log, &log, |
402 | likely(mergeable) ? UIO_MAXIOV : 1); | |
8dd014ad DS |
403 | /* On error, stop handling until the next kick. */ |
404 | if (unlikely(headcount < 0)) | |
405 | break; | |
406 | /* OK, now we need to know about added descriptors. */ | |
407 | if (!headcount) { | |
8ea8cf89 | 408 | if (unlikely(vhost_enable_notify(&net->dev, vq))) { |
8dd014ad DS |
409 | /* They have slipped one in as we were |
410 | * doing that: check again. */ | |
8ea8cf89 | 411 | vhost_disable_notify(&net->dev, vq); |
8dd014ad DS |
412 | continue; |
413 | } | |
414 | /* Nothing new? Wait for eventfd to tell us | |
415 | * they refilled. */ | |
416 | break; | |
417 | } | |
418 | /* We don't need to be notified again. */ | |
419 | if (unlikely((vhost_hlen))) | |
420 | /* Skip header. TODO: support TSO. */ | |
421 | move_iovec_hdr(vq->iov, vq->hdr, vhost_hlen, in); | |
422 | else | |
423 | /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF: | |
a290aec8 | 424 | * needed because recvmsg can modify msg_iov. */ |
8dd014ad DS |
425 | copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in); |
426 | msg.msg_iovlen = in; | |
427 | err = sock->ops->recvmsg(NULL, sock, &msg, | |
428 | sock_len, MSG_DONTWAIT | MSG_TRUNC); | |
429 | /* Userspace might have consumed the packet meanwhile: | |
430 | * it's not supposed to do this usually, but might be hard | |
431 | * to prevent. Discard data we got (if any) and keep going. */ | |
432 | if (unlikely(err != sock_len)) { | |
433 | pr_debug("Discarded rx packet: " | |
434 | " len %d, expected %zd\n", err, sock_len); | |
435 | vhost_discard_vq_desc(vq, headcount); | |
436 | continue; | |
437 | } | |
438 | if (unlikely(vhost_hlen) && | |
439 | memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0, | |
440 | vhost_hlen)) { | |
441 | vq_err(vq, "Unable to write vnet_hdr at addr %p\n", | |
442 | vq->iov->iov_base); | |
443 | break; | |
444 | } | |
445 | /* TODO: Should check and handle checksum. */ | |
cfbdab95 | 446 | if (likely(mergeable) && |
8dd014ad DS |
447 | memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount, |
448 | offsetof(typeof(hdr), num_buffers), | |
449 | sizeof hdr.num_buffers)) { | |
450 | vq_err(vq, "Failed num_buffers write"); | |
451 | vhost_discard_vq_desc(vq, headcount); | |
452 | break; | |
453 | } | |
454 | vhost_add_used_and_signal_n(&net->dev, vq, vq->heads, | |
455 | headcount); | |
456 | if (unlikely(vq_log)) | |
457 | vhost_log_write(vq, vq_log, log, vhost_len); | |
458 | total_len += vhost_len; | |
459 | if (unlikely(total_len >= VHOST_NET_WEIGHT)) { | |
460 | vhost_poll_queue(&vq->poll); | |
461 | break; | |
462 | } | |
463 | } | |
464 | ||
465 | mutex_unlock(&vq->mutex); | |
8dd014ad DS |
466 | } |
467 | ||
c23f3445 | 468 | static void handle_tx_kick(struct vhost_work *work) |
3a4d5c94 | 469 | { |
c23f3445 TH |
470 | struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, |
471 | poll.work); | |
472 | struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev); | |
473 | ||
3a4d5c94 MT |
474 | handle_tx(net); |
475 | } | |
476 | ||
c23f3445 | 477 | static void handle_rx_kick(struct vhost_work *work) |
3a4d5c94 | 478 | { |
c23f3445 TH |
479 | struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, |
480 | poll.work); | |
481 | struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev); | |
482 | ||
3a4d5c94 MT |
483 | handle_rx(net); |
484 | } | |
485 | ||
c23f3445 | 486 | static void handle_tx_net(struct vhost_work *work) |
3a4d5c94 | 487 | { |
c23f3445 TH |
488 | struct vhost_net *net = container_of(work, struct vhost_net, |
489 | poll[VHOST_NET_VQ_TX].work); | |
3a4d5c94 MT |
490 | handle_tx(net); |
491 | } | |
492 | ||
c23f3445 | 493 | static void handle_rx_net(struct vhost_work *work) |
3a4d5c94 | 494 | { |
c23f3445 TH |
495 | struct vhost_net *net = container_of(work, struct vhost_net, |
496 | poll[VHOST_NET_VQ_RX].work); | |
3a4d5c94 MT |
497 | handle_rx(net); |
498 | } | |
499 | ||
500 | static int vhost_net_open(struct inode *inode, struct file *f) | |
501 | { | |
502 | struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL); | |
c23f3445 | 503 | struct vhost_dev *dev; |
3a4d5c94 | 504 | int r; |
c23f3445 | 505 | |
3a4d5c94 MT |
506 | if (!n) |
507 | return -ENOMEM; | |
c23f3445 TH |
508 | |
509 | dev = &n->dev; | |
3a4d5c94 MT |
510 | n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick; |
511 | n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick; | |
c23f3445 | 512 | r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX); |
3a4d5c94 MT |
513 | if (r < 0) { |
514 | kfree(n); | |
515 | return r; | |
516 | } | |
517 | ||
c23f3445 TH |
518 | vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev); |
519 | vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev); | |
3a4d5c94 MT |
520 | n->tx_poll_state = VHOST_NET_POLL_DISABLED; |
521 | ||
522 | f->private_data = n; | |
523 | ||
524 | return 0; | |
525 | } | |
526 | ||
527 | static void vhost_net_disable_vq(struct vhost_net *n, | |
528 | struct vhost_virtqueue *vq) | |
529 | { | |
530 | if (!vq->private_data) | |
531 | return; | |
532 | if (vq == n->vqs + VHOST_NET_VQ_TX) { | |
533 | tx_poll_stop(n); | |
534 | n->tx_poll_state = VHOST_NET_POLL_DISABLED; | |
535 | } else | |
536 | vhost_poll_stop(n->poll + VHOST_NET_VQ_RX); | |
537 | } | |
538 | ||
539 | static void vhost_net_enable_vq(struct vhost_net *n, | |
540 | struct vhost_virtqueue *vq) | |
541 | { | |
28457ee6 AB |
542 | struct socket *sock; |
543 | ||
544 | sock = rcu_dereference_protected(vq->private_data, | |
545 | lockdep_is_held(&vq->mutex)); | |
3a4d5c94 MT |
546 | if (!sock) |
547 | return; | |
548 | if (vq == n->vqs + VHOST_NET_VQ_TX) { | |
549 | n->tx_poll_state = VHOST_NET_POLL_STOPPED; | |
550 | tx_poll_start(n, sock); | |
551 | } else | |
552 | vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file); | |
553 | } | |
554 | ||
555 | static struct socket *vhost_net_stop_vq(struct vhost_net *n, | |
556 | struct vhost_virtqueue *vq) | |
557 | { | |
558 | struct socket *sock; | |
559 | ||
560 | mutex_lock(&vq->mutex); | |
28457ee6 AB |
561 | sock = rcu_dereference_protected(vq->private_data, |
562 | lockdep_is_held(&vq->mutex)); | |
3a4d5c94 MT |
563 | vhost_net_disable_vq(n, vq); |
564 | rcu_assign_pointer(vq->private_data, NULL); | |
565 | mutex_unlock(&vq->mutex); | |
566 | return sock; | |
567 | } | |
568 | ||
569 | static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock, | |
570 | struct socket **rx_sock) | |
571 | { | |
572 | *tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX); | |
573 | *rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX); | |
574 | } | |
575 | ||
576 | static void vhost_net_flush_vq(struct vhost_net *n, int index) | |
577 | { | |
578 | vhost_poll_flush(n->poll + index); | |
579 | vhost_poll_flush(&n->dev.vqs[index].poll); | |
580 | } | |
581 | ||
582 | static void vhost_net_flush(struct vhost_net *n) | |
583 | { | |
584 | vhost_net_flush_vq(n, VHOST_NET_VQ_TX); | |
585 | vhost_net_flush_vq(n, VHOST_NET_VQ_RX); | |
586 | } | |
587 | ||
588 | static int vhost_net_release(struct inode *inode, struct file *f) | |
589 | { | |
590 | struct vhost_net *n = f->private_data; | |
591 | struct socket *tx_sock; | |
592 | struct socket *rx_sock; | |
593 | ||
594 | vhost_net_stop(n, &tx_sock, &rx_sock); | |
595 | vhost_net_flush(n); | |
ea5d4046 | 596 | vhost_dev_cleanup(&n->dev, false); |
3a4d5c94 MT |
597 | if (tx_sock) |
598 | fput(tx_sock->file); | |
599 | if (rx_sock) | |
600 | fput(rx_sock->file); | |
601 | /* We do an extra flush before freeing memory, | |
602 | * since jobs can re-queue themselves. */ | |
603 | vhost_net_flush(n); | |
604 | kfree(n); | |
605 | return 0; | |
606 | } | |
607 | ||
608 | static struct socket *get_raw_socket(int fd) | |
609 | { | |
610 | struct { | |
611 | struct sockaddr_ll sa; | |
612 | char buf[MAX_ADDR_LEN]; | |
613 | } uaddr; | |
614 | int uaddr_len = sizeof uaddr, r; | |
615 | struct socket *sock = sockfd_lookup(fd, &r); | |
d47effe1 | 616 | |
3a4d5c94 MT |
617 | if (!sock) |
618 | return ERR_PTR(-ENOTSOCK); | |
619 | ||
620 | /* Parameter checking */ | |
621 | if (sock->sk->sk_type != SOCK_RAW) { | |
622 | r = -ESOCKTNOSUPPORT; | |
623 | goto err; | |
624 | } | |
625 | ||
626 | r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa, | |
627 | &uaddr_len, 0); | |
628 | if (r) | |
629 | goto err; | |
630 | ||
631 | if (uaddr.sa.sll_family != AF_PACKET) { | |
632 | r = -EPFNOSUPPORT; | |
633 | goto err; | |
634 | } | |
635 | return sock; | |
636 | err: | |
637 | fput(sock->file); | |
638 | return ERR_PTR(r); | |
639 | } | |
640 | ||
501c774c | 641 | static struct socket *get_tap_socket(int fd) |
3a4d5c94 MT |
642 | { |
643 | struct file *file = fget(fd); | |
644 | struct socket *sock; | |
d47effe1 | 645 | |
3a4d5c94 MT |
646 | if (!file) |
647 | return ERR_PTR(-EBADF); | |
648 | sock = tun_get_socket(file); | |
501c774c AB |
649 | if (!IS_ERR(sock)) |
650 | return sock; | |
651 | sock = macvtap_get_socket(file); | |
3a4d5c94 MT |
652 | if (IS_ERR(sock)) |
653 | fput(file); | |
654 | return sock; | |
655 | } | |
656 | ||
657 | static struct socket *get_socket(int fd) | |
658 | { | |
659 | struct socket *sock; | |
d47effe1 | 660 | |
3a4d5c94 MT |
661 | /* special case to disable backend */ |
662 | if (fd == -1) | |
663 | return NULL; | |
664 | sock = get_raw_socket(fd); | |
665 | if (!IS_ERR(sock)) | |
666 | return sock; | |
501c774c | 667 | sock = get_tap_socket(fd); |
3a4d5c94 MT |
668 | if (!IS_ERR(sock)) |
669 | return sock; | |
670 | return ERR_PTR(-ENOTSOCK); | |
671 | } | |
672 | ||
673 | static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) | |
674 | { | |
675 | struct socket *sock, *oldsock; | |
676 | struct vhost_virtqueue *vq; | |
bab632d6 | 677 | struct vhost_ubuf_ref *ubufs, *oldubufs = NULL; |
3a4d5c94 MT |
678 | int r; |
679 | ||
680 | mutex_lock(&n->dev.mutex); | |
681 | r = vhost_dev_check_owner(&n->dev); | |
682 | if (r) | |
683 | goto err; | |
684 | ||
685 | if (index >= VHOST_NET_VQ_MAX) { | |
686 | r = -ENOBUFS; | |
687 | goto err; | |
688 | } | |
689 | vq = n->vqs + index; | |
690 | mutex_lock(&vq->mutex); | |
691 | ||
692 | /* Verify that ring has been setup correctly. */ | |
693 | if (!vhost_vq_access_ok(vq)) { | |
694 | r = -EFAULT; | |
1dace8c8 | 695 | goto err_vq; |
3a4d5c94 MT |
696 | } |
697 | sock = get_socket(fd); | |
698 | if (IS_ERR(sock)) { | |
699 | r = PTR_ERR(sock); | |
1dace8c8 | 700 | goto err_vq; |
3a4d5c94 MT |
701 | } |
702 | ||
703 | /* start polling new socket */ | |
28457ee6 AB |
704 | oldsock = rcu_dereference_protected(vq->private_data, |
705 | lockdep_is_held(&vq->mutex)); | |
11fe8839 | 706 | if (sock != oldsock) { |
bab632d6 MT |
707 | ubufs = vhost_ubuf_alloc(vq, sock && vhost_sock_zcopy(sock)); |
708 | if (IS_ERR(ubufs)) { | |
709 | r = PTR_ERR(ubufs); | |
710 | goto err_ubufs; | |
711 | } | |
712 | oldubufs = vq->ubufs; | |
713 | vq->ubufs = ubufs; | |
d47effe1 KK |
714 | vhost_net_disable_vq(n, vq); |
715 | rcu_assign_pointer(vq->private_data, sock); | |
716 | vhost_net_enable_vq(n, vq); | |
f59281da JW |
717 | |
718 | r = vhost_init_used(vq); | |
719 | if (r) | |
720 | goto err_vq; | |
dd1f4078 | 721 | } |
3a4d5c94 | 722 | |
1680e906 MT |
723 | mutex_unlock(&vq->mutex); |
724 | ||
c047e5f3 | 725 | if (oldubufs) { |
bab632d6 | 726 | vhost_ubuf_put_and_wait(oldubufs); |
c047e5f3 MT |
727 | mutex_lock(&vq->mutex); |
728 | vhost_zerocopy_signal_used(vq); | |
729 | mutex_unlock(&vq->mutex); | |
730 | } | |
bab632d6 | 731 | |
3a4d5c94 MT |
732 | if (oldsock) { |
733 | vhost_net_flush_vq(n, index); | |
734 | fput(oldsock->file); | |
735 | } | |
1dace8c8 | 736 | |
1680e906 MT |
737 | mutex_unlock(&n->dev.mutex); |
738 | return 0; | |
739 | ||
bab632d6 MT |
740 | err_ubufs: |
741 | fput(sock->file); | |
1dace8c8 JD |
742 | err_vq: |
743 | mutex_unlock(&vq->mutex); | |
3a4d5c94 MT |
744 | err: |
745 | mutex_unlock(&n->dev.mutex); | |
746 | return r; | |
747 | } | |
748 | ||
749 | static long vhost_net_reset_owner(struct vhost_net *n) | |
750 | { | |
751 | struct socket *tx_sock = NULL; | |
752 | struct socket *rx_sock = NULL; | |
753 | long err; | |
d47effe1 | 754 | |
3a4d5c94 MT |
755 | mutex_lock(&n->dev.mutex); |
756 | err = vhost_dev_check_owner(&n->dev); | |
757 | if (err) | |
758 | goto done; | |
759 | vhost_net_stop(n, &tx_sock, &rx_sock); | |
760 | vhost_net_flush(n); | |
761 | err = vhost_dev_reset_owner(&n->dev); | |
762 | done: | |
763 | mutex_unlock(&n->dev.mutex); | |
764 | if (tx_sock) | |
765 | fput(tx_sock->file); | |
766 | if (rx_sock) | |
767 | fput(rx_sock->file); | |
768 | return err; | |
769 | } | |
770 | ||
771 | static int vhost_net_set_features(struct vhost_net *n, u64 features) | |
772 | { | |
8dd014ad | 773 | size_t vhost_hlen, sock_hlen, hdr_len; |
3a4d5c94 | 774 | int i; |
8dd014ad DS |
775 | |
776 | hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ? | |
777 | sizeof(struct virtio_net_hdr_mrg_rxbuf) : | |
778 | sizeof(struct virtio_net_hdr); | |
779 | if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) { | |
780 | /* vhost provides vnet_hdr */ | |
781 | vhost_hlen = hdr_len; | |
782 | sock_hlen = 0; | |
783 | } else { | |
784 | /* socket provides vnet_hdr */ | |
785 | vhost_hlen = 0; | |
786 | sock_hlen = hdr_len; | |
787 | } | |
3a4d5c94 MT |
788 | mutex_lock(&n->dev.mutex); |
789 | if ((features & (1 << VHOST_F_LOG_ALL)) && | |
790 | !vhost_log_access_ok(&n->dev)) { | |
791 | mutex_unlock(&n->dev.mutex); | |
792 | return -EFAULT; | |
793 | } | |
794 | n->dev.acked_features = features; | |
795 | smp_wmb(); | |
796 | for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { | |
797 | mutex_lock(&n->vqs[i].mutex); | |
8dd014ad DS |
798 | n->vqs[i].vhost_hlen = vhost_hlen; |
799 | n->vqs[i].sock_hlen = sock_hlen; | |
3a4d5c94 MT |
800 | mutex_unlock(&n->vqs[i].mutex); |
801 | } | |
802 | vhost_net_flush(n); | |
803 | mutex_unlock(&n->dev.mutex); | |
804 | return 0; | |
805 | } | |
806 | ||
807 | static long vhost_net_ioctl(struct file *f, unsigned int ioctl, | |
808 | unsigned long arg) | |
809 | { | |
810 | struct vhost_net *n = f->private_data; | |
811 | void __user *argp = (void __user *)arg; | |
812 | u64 __user *featurep = argp; | |
813 | struct vhost_vring_file backend; | |
814 | u64 features; | |
815 | int r; | |
d47effe1 | 816 | |
3a4d5c94 MT |
817 | switch (ioctl) { |
818 | case VHOST_NET_SET_BACKEND: | |
d3553a52 TY |
819 | if (copy_from_user(&backend, argp, sizeof backend)) |
820 | return -EFAULT; | |
3a4d5c94 MT |
821 | return vhost_net_set_backend(n, backend.index, backend.fd); |
822 | case VHOST_GET_FEATURES: | |
823 | features = VHOST_FEATURES; | |
d3553a52 TY |
824 | if (copy_to_user(featurep, &features, sizeof features)) |
825 | return -EFAULT; | |
826 | return 0; | |
3a4d5c94 | 827 | case VHOST_SET_FEATURES: |
d3553a52 TY |
828 | if (copy_from_user(&features, featurep, sizeof features)) |
829 | return -EFAULT; | |
3a4d5c94 MT |
830 | if (features & ~VHOST_FEATURES) |
831 | return -EOPNOTSUPP; | |
832 | return vhost_net_set_features(n, features); | |
833 | case VHOST_RESET_OWNER: | |
834 | return vhost_net_reset_owner(n); | |
835 | default: | |
836 | mutex_lock(&n->dev.mutex); | |
837 | r = vhost_dev_ioctl(&n->dev, ioctl, arg); | |
838 | vhost_net_flush(n); | |
839 | mutex_unlock(&n->dev.mutex); | |
840 | return r; | |
841 | } | |
842 | } | |
843 | ||
844 | #ifdef CONFIG_COMPAT | |
845 | static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl, | |
846 | unsigned long arg) | |
847 | { | |
848 | return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg)); | |
849 | } | |
850 | #endif | |
851 | ||
373a83a6 | 852 | static const struct file_operations vhost_net_fops = { |
3a4d5c94 MT |
853 | .owner = THIS_MODULE, |
854 | .release = vhost_net_release, | |
855 | .unlocked_ioctl = vhost_net_ioctl, | |
856 | #ifdef CONFIG_COMPAT | |
857 | .compat_ioctl = vhost_net_compat_ioctl, | |
858 | #endif | |
859 | .open = vhost_net_open, | |
6038f373 | 860 | .llseek = noop_llseek, |
3a4d5c94 MT |
861 | }; |
862 | ||
863 | static struct miscdevice vhost_net_misc = { | |
7c7c7f01 | 864 | .minor = VHOST_NET_MINOR, |
865 | .name = "vhost-net", | |
866 | .fops = &vhost_net_fops, | |
3a4d5c94 MT |
867 | }; |
868 | ||
a8d3782f | 869 | static int vhost_net_init(void) |
3a4d5c94 | 870 | { |
bab632d6 MT |
871 | if (experimental_zcopytx) |
872 | vhost_enable_zcopy(VHOST_NET_VQ_TX); | |
c23f3445 | 873 | return misc_register(&vhost_net_misc); |
3a4d5c94 MT |
874 | } |
875 | module_init(vhost_net_init); | |
876 | ||
a8d3782f | 877 | static void vhost_net_exit(void) |
3a4d5c94 MT |
878 | { |
879 | misc_deregister(&vhost_net_misc); | |
3a4d5c94 MT |
880 | } |
881 | module_exit(vhost_net_exit); | |
882 | ||
883 | MODULE_VERSION("0.0.1"); | |
884 | MODULE_LICENSE("GPL v2"); | |
885 | MODULE_AUTHOR("Michael S. Tsirkin"); | |
886 | MODULE_DESCRIPTION("Host kernel accelerator for virtio net"); | |
7c7c7f01 | 887 | MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR); |
888 | MODULE_ALIAS("devname:vhost-net"); |