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Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +00001/* 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>
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +000013#include <linux/miscdevice.h>
14#include <linux/module.h>
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +000015#include <linux/moduleparam.h>
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +000016#include <linux/mutex.h>
17#include <linux/workqueue.h>
18#include <linux/rcupdate.h>
19#include <linux/file.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090020#include <linux/slab.h>
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +000021
22#include <linux/net.h>
23#include <linux/if_packet.h>
24#include <linux/if_arp.h>
25#include <linux/if_tun.h>
Arnd Bergmann501c7742010-02-18 05:46:50 +000026#include <linux/if_macvlan.h>
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +000027
28#include <net/sock.h>
29
30#include "vhost.h"
31
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +000032static int experimental_zcopytx;
33module_param(experimental_zcopytx, int, 0444);
34MODULE_PARM_DESC(experimental_zcopytx, "Enable Experimental Zero Copy TX");
35
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +000036/* 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
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +000040/* MAX number of TX used buffers for outstanding zerocopy */
41#define VHOST_MAX_PEND 128
42#define VHOST_GOODCOPY_LEN 256
43
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +000044enum {
45 VHOST_NET_VQ_RX = 0,
46 VHOST_NET_VQ_TX = 1,
47 VHOST_NET_VQ_MAX = 2,
48};
49
50enum vhost_net_poll_state {
51 VHOST_NET_POLL_DISABLED = 0,
52 VHOST_NET_POLL_STARTED = 1,
53 VHOST_NET_POLL_STOPPED = 2,
54};
55
56struct 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
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +000066static bool vhost_sock_zcopy(struct socket *sock)
67{
68 return unlikely(experimental_zcopytx) &&
69 sock_flag(sock->sk, SOCK_ZEROCOPY);
70}
71
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +000072/* Pop first len bytes from iovec. Return number of segments used. */
73static 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;
Krishna Kumard47effe2011-03-01 17:06:37 +053078
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +000079 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}
David Stevens8dd014a2010-07-27 18:52:21 +030092/* Copy iovec entries for len bytes from iovec. */
93static 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;
Krishna Kumard47effe2011-03-01 17:06:37 +053098
David Stevens8dd014a2010-07-27 18:52:21 +030099 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}
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000109
110/* Caller must have TX VQ lock */
111static 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 */
120static 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. */
130static void handle_tx(struct vhost_net *net)
131{
132 struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX];
Michael S. Tsirkind5675bd2010-06-24 16:59:59 +0300133 unsigned out, in, s;
134 int head;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000135 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;
Arnd Bergmann28457ee2010-03-09 19:24:45 +0100146 struct socket *sock;
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000147 struct vhost_ubuf_ref *uninitialized_var(ubufs);
148 bool zcopy;
Arnd Bergmann28457ee2010-03-09 19:24:45 +0100149
Michael S. Tsirkin5e182472011-01-18 13:04:43 +0200150 /* TODO: check that we are running from vhost_worker? */
Michael S. Tsirkin11cd1a82010-11-14 17:31:52 +0200151 sock = rcu_dereference_check(vq->private_data, 1);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000152 if (!sock)
153 return;
154
155 wmem = atomic_read(&sock->sk->sk_wmem_alloc);
Sridhar Samudrala39286fa2010-02-28 19:39:16 +0200156 if (wmem >= sock->sk->sk_sndbuf) {
157 mutex_lock(&vq->mutex);
158 tx_poll_start(net, sock);
159 mutex_unlock(&vq->mutex);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000160 return;
Sridhar Samudrala39286fa2010-02-28 19:39:16 +0200161 }
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000162
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000163 mutex_lock(&vq->mutex);
Michael S. Tsirkin8ea8cf82011-05-20 02:10:54 +0300164 vhost_disable_notify(&net->dev, vq);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000165
Michael S. Tsirkin0e255572010-03-08 23:24:22 +0200166 if (wmem < sock->sk->sk_sndbuf / 2)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000167 tx_poll_stop(net);
David Stevens8dd014a2010-07-27 18:52:21 +0300168 hdr_size = vq->vhost_hlen;
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000169 zcopy = vhost_sock_zcopy(sock);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000170
171 for (;;) {
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000172 /* Release DMAs done buffers first */
173 if (zcopy)
174 vhost_zerocopy_signal_used(vq);
175
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000176 head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
177 ARRAY_SIZE(vq->iov),
178 &out, &in,
179 NULL, NULL);
Michael S. Tsirkind5675bd2010-06-24 16:59:59 +0300180 /* On error, stop handling until the next kick. */
Michael S. Tsirkin7b3384f2010-07-01 18:40:12 +0300181 if (unlikely(head < 0))
Michael S. Tsirkind5675bd2010-06-24 16:59:59 +0300182 break;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000183 /* Nothing new? Wait for eventfd to tell us they refilled. */
184 if (head == vq->num) {
Shirley Ma9e380822011-07-20 10:23:12 -0700185 int num_pends;
186
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000187 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 }
Shirley Ma9e380822011-07-20 10:23:12 -0700193 /* 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)) {
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000200 tx_poll_start(net, sock);
201 set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
202 break;
203 }
Michael S. Tsirkin8ea8cf82011-05-20 02:10:54 +0300204 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
205 vhost_disable_notify(&net->dev, vq);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000206 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 }
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000226 /* 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 }
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000250 /* TODO: Check specific error and bomb out unless ENOBUFS? */
251 err = sock->ops->sendmsg(NULL, sock, &msg, len);
252 if (unlikely(err < 0)) {
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000253 if (zcopy) {
254 if (ubufs)
255 vhost_ubuf_put(ubufs);
256 vq->upend_idx = ((unsigned)vq->upend_idx - 1) %
257 UIO_MAXIOV;
258 }
David Stevens8dd014a2010-07-27 18:52:21 +0300259 vhost_discard_vq_desc(vq, 1);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000260 tx_poll_start(net, sock);
261 break;
262 }
263 if (err != len)
Michael S. Tsirkin95c0ec62010-06-24 17:10:25 +0300264 pr_debug("Truncated TX packet: "
265 " len %d != %zd\n", err, len);
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000266 if (!zcopy)
267 vhost_add_used_and_signal(&net->dev, vq, head, 0);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000268 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);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000276}
277
David Stevens8dd014a2010-07-27 18:52:21 +0300278static int peek_head_len(struct sock *sk)
279{
280 struct sk_buff *head;
281 int len = 0;
Jason Wang783e3982011-01-17 16:11:17 +0800282 unsigned long flags;
David Stevens8dd014a2010-07-27 18:52:21 +0300283
Jason Wang783e3982011-01-17 16:11:17 +0800284 spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
David Stevens8dd014a2010-07-27 18:52:21 +0300285 head = skb_peek(&sk->sk_receive_queue);
Jason Wang783e3982011-01-17 16:11:17 +0800286 if (likely(head))
David Stevens8dd014a2010-07-27 18:52:21 +0300287 len = head->len;
Jason Wang783e3982011-01-17 16:11:17 +0800288 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
David Stevens8dd014a2010-07-27 18:52:21 +0300289 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
Jason Wang94249362011-01-17 16:11:08 +0800299 * @quota - headcount quota, 1 for big buffer
David Stevens8dd014a2010-07-27 18:52:21 +0300300 * returns number of buffer heads allocated, negative on error
301 */
302static 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,
Jason Wang94249362011-01-17 16:11:08 +0800307 unsigned *log_num,
308 unsigned int quota)
David Stevens8dd014a2010-07-27 18:52:21 +0300309{
310 unsigned int out, in;
311 int seg = 0;
312 int headcount = 0;
313 unsigned d;
314 int r, nlogs = 0;
315
Jason Wang94249362011-01-17 16:11:08 +0800316 while (datalen > 0 && headcount < quota) {
Jason Wange0e9b402010-09-14 23:53:05 +0800317 if (unlikely(seg >= UIO_MAXIOV)) {
David Stevens8dd014a2010-07-27 18:52:21 +0300318 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;
349err:
350 vhost_discard_vq_desc(vq, headcount);
351 return r;
352}
353
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000354/* Expects to be always run from workqueue - which acts as
355 * read-size critical section for our kind of RCU. */
Jason Wang94249362011-01-17 16:11:08 +0800356static void handle_rx(struct vhost_net *net)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000357{
David Stevens8dd014a2010-07-27 18:52:21 +0300358 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 };
David Stevens8dd014a2010-07-27 18:52:21 +0300369 struct virtio_net_hdr_mrg_rxbuf hdr = {
370 .hdr.flags = 0,
371 .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE
372 };
David Stevens8dd014a2010-07-27 18:52:21 +0300373 size_t total_len = 0;
Jason Wangcfbdab92011-01-17 16:10:59 +0800374 int err, headcount, mergeable;
David Stevens8dd014a2010-07-27 18:52:21 +0300375 size_t vhost_hlen, sock_hlen;
376 size_t vhost_len, sock_len;
Michael S. Tsirkin5e182472011-01-18 13:04:43 +0200377 /* TODO: check that we are running from vhost_worker? */
378 struct socket *sock = rcu_dereference_check(vq->private_data, 1);
Krishna Kumard47effe2011-03-01 17:06:37 +0530379
Michael S. Tsirkinde4d7682011-03-13 23:00:52 +0200380 if (!sock)
David Stevens8dd014a2010-07-27 18:52:21 +0300381 return;
382
David Stevens8dd014a2010-07-27 18:52:21 +0300383 mutex_lock(&vq->mutex);
Michael S. Tsirkin8ea8cf82011-05-20 02:10:54 +0300384 vhost_disable_notify(&net->dev, vq);
David Stevens8dd014a2010-07-27 18:52:21 +0300385 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;
Jason Wangcfbdab92011-01-17 16:10:59 +0800390 mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF);
David Stevens8dd014a2010-07-27 18:52:21 +0300391
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,
Jason Wang94249362011-01-17 16:11:08 +0800396 &in, vq_log, &log,
397 likely(mergeable) ? UIO_MAXIOV : 1);
David Stevens8dd014a2010-07-27 18:52:21 +0300398 /* 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) {
Michael S. Tsirkin8ea8cf82011-05-20 02:10:54 +0300403 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
David Stevens8dd014a2010-07-27 18:52:21 +0300404 /* They have slipped one in as we were
405 * doing that: check again. */
Michael S. Tsirkin8ea8cf82011-05-20 02:10:54 +0300406 vhost_disable_notify(&net->dev, vq);
David Stevens8dd014a2010-07-27 18:52:21 +0300407 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:
Jason Wanga290aec2010-11-29 13:48:40 +0800419 * needed because recvmsg can modify msg_iov. */
David Stevens8dd014a2010-07-27 18:52:21 +0300420 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. */
Jason Wangcfbdab92011-01-17 16:10:59 +0800441 if (likely(mergeable) &&
David Stevens8dd014a2010-07-27 18:52:21 +0300442 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);
David Stevens8dd014a2010-07-27 18:52:21 +0300461}
462
Tejun Heoc23f3442010-06-02 20:40:00 +0200463static void handle_tx_kick(struct vhost_work *work)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000464{
Tejun Heoc23f3442010-06-02 20:40:00 +0200465 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
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000469 handle_tx(net);
470}
471
Tejun Heoc23f3442010-06-02 20:40:00 +0200472static void handle_rx_kick(struct vhost_work *work)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000473{
Tejun Heoc23f3442010-06-02 20:40:00 +0200474 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
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000478 handle_rx(net);
479}
480
Tejun Heoc23f3442010-06-02 20:40:00 +0200481static void handle_tx_net(struct vhost_work *work)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000482{
Tejun Heoc23f3442010-06-02 20:40:00 +0200483 struct vhost_net *net = container_of(work, struct vhost_net,
484 poll[VHOST_NET_VQ_TX].work);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000485 handle_tx(net);
486}
487
Tejun Heoc23f3442010-06-02 20:40:00 +0200488static void handle_rx_net(struct vhost_work *work)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000489{
Tejun Heoc23f3442010-06-02 20:40:00 +0200490 struct vhost_net *net = container_of(work, struct vhost_net,
491 poll[VHOST_NET_VQ_RX].work);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000492 handle_rx(net);
493}
494
495static int vhost_net_open(struct inode *inode, struct file *f)
496{
497 struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
Tejun Heoc23f3442010-06-02 20:40:00 +0200498 struct vhost_dev *dev;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000499 int r;
Tejun Heoc23f3442010-06-02 20:40:00 +0200500
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000501 if (!n)
502 return -ENOMEM;
Tejun Heoc23f3442010-06-02 20:40:00 +0200503
504 dev = &n->dev;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000505 n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick;
506 n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick;
Tejun Heoc23f3442010-06-02 20:40:00 +0200507 r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000508 if (r < 0) {
509 kfree(n);
510 return r;
511 }
512
Tejun Heoc23f3442010-06-02 20:40:00 +0200513 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);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000515 n->tx_poll_state = VHOST_NET_POLL_DISABLED;
516
517 f->private_data = n;
518
519 return 0;
520}
521
522static 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
534static void vhost_net_enable_vq(struct vhost_net *n,
535 struct vhost_virtqueue *vq)
536{
Arnd Bergmann28457ee2010-03-09 19:24:45 +0100537 struct socket *sock;
538
539 sock = rcu_dereference_protected(vq->private_data,
540 lockdep_is_held(&vq->mutex));
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000541 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
550static 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);
Arnd Bergmann28457ee2010-03-09 19:24:45 +0100556 sock = rcu_dereference_protected(vq->private_data,
557 lockdep_is_held(&vq->mutex));
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000558 vhost_net_disable_vq(n, vq);
559 rcu_assign_pointer(vq->private_data, NULL);
560 mutex_unlock(&vq->mutex);
561 return sock;
562}
563
564static 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
571static 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
577static 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
583static 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);
591 vhost_dev_cleanup(&n->dev);
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
603static 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);
Krishna Kumard47effe2011-03-01 17:06:37 +0530611
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000612 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;
631err:
632 fput(sock->file);
633 return ERR_PTR(r);
634}
635
Arnd Bergmann501c7742010-02-18 05:46:50 +0000636static struct socket *get_tap_socket(int fd)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000637{
638 struct file *file = fget(fd);
639 struct socket *sock;
Krishna Kumard47effe2011-03-01 17:06:37 +0530640
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000641 if (!file)
642 return ERR_PTR(-EBADF);
643 sock = tun_get_socket(file);
Arnd Bergmann501c7742010-02-18 05:46:50 +0000644 if (!IS_ERR(sock))
645 return sock;
646 sock = macvtap_get_socket(file);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000647 if (IS_ERR(sock))
648 fput(file);
649 return sock;
650}
651
652static struct socket *get_socket(int fd)
653{
654 struct socket *sock;
Krishna Kumard47effe2011-03-01 17:06:37 +0530655
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000656 /* 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;
Arnd Bergmann501c7742010-02-18 05:46:50 +0000662 sock = get_tap_socket(fd);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000663 if (!IS_ERR(sock))
664 return sock;
665 return ERR_PTR(-ENOTSOCK);
666}
667
668static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
669{
670 struct socket *sock, *oldsock;
671 struct vhost_virtqueue *vq;
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000672 struct vhost_ubuf_ref *ubufs, *oldubufs = NULL;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000673 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;
Jeff Dike1dace8c2010-03-04 16:10:14 -0500690 goto err_vq;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000691 }
692 sock = get_socket(fd);
693 if (IS_ERR(sock)) {
694 r = PTR_ERR(sock);
Jeff Dike1dace8c2010-03-04 16:10:14 -0500695 goto err_vq;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000696 }
697
698 /* start polling new socket */
Arnd Bergmann28457ee2010-03-09 19:24:45 +0100699 oldsock = rcu_dereference_protected(vq->private_data,
700 lockdep_is_held(&vq->mutex));
David S. Miller11fe8832010-07-20 18:25:24 -0700701 if (sock != oldsock) {
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000702 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;
Krishna Kumard47effe2011-03-01 17:06:37 +0530709 vhost_net_disable_vq(n, vq);
710 rcu_assign_pointer(vq->private_data, sock);
711 vhost_net_enable_vq(n, vq);
Jason Wangf59281d2011-06-21 18:04:27 +0800712
713 r = vhost_init_used(vq);
714 if (r)
715 goto err_vq;
Jeff Dikedd1f4072010-03-04 16:10:14 -0500716 }
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000717
Michael S. Tsirkin1680e902010-07-15 15:19:12 +0300718 mutex_unlock(&vq->mutex);
719
Michael S. Tsirkinc047e5f2011-07-20 13:41:31 +0300720 if (oldubufs) {
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000721 vhost_ubuf_put_and_wait(oldubufs);
Michael S. Tsirkinc047e5f2011-07-20 13:41:31 +0300722 mutex_lock(&vq->mutex);
723 vhost_zerocopy_signal_used(vq);
724 mutex_unlock(&vq->mutex);
725 }
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000726
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000727 if (oldsock) {
728 vhost_net_flush_vq(n, index);
729 fput(oldsock->file);
730 }
Jeff Dike1dace8c2010-03-04 16:10:14 -0500731
Michael S. Tsirkin1680e902010-07-15 15:19:12 +0300732 mutex_unlock(&n->dev.mutex);
733 return 0;
734
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000735err_ubufs:
736 fput(sock->file);
Jeff Dike1dace8c2010-03-04 16:10:14 -0500737err_vq:
738 mutex_unlock(&vq->mutex);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000739err:
740 mutex_unlock(&n->dev.mutex);
741 return r;
742}
743
744static 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;
Krishna Kumard47effe2011-03-01 17:06:37 +0530749
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000750 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);
757done:
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
766static int vhost_net_set_features(struct vhost_net *n, u64 features)
767{
David Stevens8dd014a2010-07-27 18:52:21 +0300768 size_t vhost_hlen, sock_hlen, hdr_len;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000769 int i;
David Stevens8dd014a2010-07-27 18:52:21 +0300770
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 }
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000783 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);
David Stevens8dd014a2010-07-27 18:52:21 +0300793 n->vqs[i].vhost_hlen = vhost_hlen;
794 n->vqs[i].sock_hlen = sock_hlen;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000795 mutex_unlock(&n->vqs[i].mutex);
796 }
797 vhost_net_flush(n);
798 mutex_unlock(&n->dev.mutex);
799 return 0;
800}
801
802static 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;
Krishna Kumard47effe2011-03-01 17:06:37 +0530811
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000812 switch (ioctl) {
813 case VHOST_NET_SET_BACKEND:
Takuya Yoshikawad3553a52010-05-27 19:01:58 +0900814 if (copy_from_user(&backend, argp, sizeof backend))
815 return -EFAULT;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000816 return vhost_net_set_backend(n, backend.index, backend.fd);
817 case VHOST_GET_FEATURES:
818 features = VHOST_FEATURES;
Takuya Yoshikawad3553a52010-05-27 19:01:58 +0900819 if (copy_to_user(featurep, &features, sizeof features))
820 return -EFAULT;
821 return 0;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000822 case VHOST_SET_FEATURES:
Takuya Yoshikawad3553a52010-05-27 19:01:58 +0900823 if (copy_from_user(&features, featurep, sizeof features))
824 return -EFAULT;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000825 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
840static 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
Tobias Klauser373a83a2010-05-17 15:12:49 +0200847static const struct file_operations vhost_net_fops = {
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000848 .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,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200855 .llseek = noop_llseek,
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000856};
857
858static struct miscdevice vhost_net_misc = {
stephen hemminger7c7c7f02012-01-11 19:30:38 +0000859 .minor = VHOST_NET_MINOR,
860 .name = "vhost-net",
861 .fops = &vhost_net_fops,
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000862};
863
Christoph Hellwiga8d37822010-04-13 14:11:25 -0400864static int vhost_net_init(void)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000865{
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000866 if (experimental_zcopytx)
867 vhost_enable_zcopy(VHOST_NET_VQ_TX);
Tejun Heoc23f3442010-06-02 20:40:00 +0200868 return misc_register(&vhost_net_misc);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000869}
870module_init(vhost_net_init);
871
Christoph Hellwiga8d37822010-04-13 14:11:25 -0400872static void vhost_net_exit(void)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000873{
874 misc_deregister(&vhost_net_misc);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000875}
876module_exit(vhost_net_exit);
877
878MODULE_VERSION("0.0.1");
879MODULE_LICENSE("GPL v2");
880MODULE_AUTHOR("Michael S. Tsirkin");
881MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
stephen hemminger7c7c7f02012-01-11 19:30:38 +0000882MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR);
883MODULE_ALIAS("devname:vhost-net");