blob: 5c170100de9ca766854c37f8d85956251653baba [file] [log] [blame]
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>
Basil Gorc53cff52012-05-03 22:55:23 +000027#include <linux/if_vlan.h>
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +000028
29#include <net/sock.h>
30
31#include "vhost.h"
32
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +000033static int experimental_zcopytx;
34module_param(experimental_zcopytx, int, 0444);
35MODULE_PARM_DESC(experimental_zcopytx, "Enable Experimental Zero Copy TX");
36
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +000037/* 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
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +000041/* MAX number of TX used buffers for outstanding zerocopy */
42#define VHOST_MAX_PEND 128
43#define VHOST_GOODCOPY_LEN 256
44
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +000045enum {
46 VHOST_NET_VQ_RX = 0,
47 VHOST_NET_VQ_TX = 1,
48 VHOST_NET_VQ_MAX = 2,
49};
50
51enum vhost_net_poll_state {
52 VHOST_NET_POLL_DISABLED = 0,
53 VHOST_NET_POLL_STARTED = 1,
54 VHOST_NET_POLL_STOPPED = 2,
55};
56
57struct 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
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +000067static bool vhost_sock_zcopy(struct socket *sock)
68{
69 return unlikely(experimental_zcopytx) &&
70 sock_flag(sock->sk, SOCK_ZEROCOPY);
71}
72
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +000073/* Pop first len bytes from iovec. Return number of segments used. */
74static 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;
Krishna Kumard47effe2011-03-01 17:06:37 +053079
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +000080 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}
David Stevens8dd014a2010-07-27 18:52:21 +030093/* Copy iovec entries for len bytes from iovec. */
94static 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;
Krishna Kumard47effe2011-03-01 17:06:37 +053099
David Stevens8dd014a2010-07-27 18:52:21 +0300100 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}
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000110
111/* Caller must have TX VQ lock */
112static 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 */
121static 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. */
131static void handle_tx(struct vhost_net *net)
132{
133 struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX];
Michael S. Tsirkind5675bd2010-06-24 16:59:59 +0300134 unsigned out, in, s;
135 int head;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000136 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;
Arnd Bergmann28457ee2010-03-09 19:24:45 +0100147 struct socket *sock;
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000148 struct vhost_ubuf_ref *uninitialized_var(ubufs);
149 bool zcopy;
Arnd Bergmann28457ee2010-03-09 19:24:45 +0100150
Michael S. Tsirkin5e182472011-01-18 13:04:43 +0200151 /* TODO: check that we are running from vhost_worker? */
Michael S. Tsirkin11cd1a82010-11-14 17:31:52 +0200152 sock = rcu_dereference_check(vq->private_data, 1);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000153 if (!sock)
154 return;
155
156 wmem = atomic_read(&sock->sk->sk_wmem_alloc);
Sridhar Samudrala39286fa2010-02-28 19:39:16 +0200157 if (wmem >= sock->sk->sk_sndbuf) {
158 mutex_lock(&vq->mutex);
159 tx_poll_start(net, sock);
160 mutex_unlock(&vq->mutex);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000161 return;
Sridhar Samudrala39286fa2010-02-28 19:39:16 +0200162 }
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000163
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000164 mutex_lock(&vq->mutex);
Michael S. Tsirkin8ea8cf82011-05-20 02:10:54 +0300165 vhost_disable_notify(&net->dev, vq);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000166
Michael S. Tsirkin0e255572010-03-08 23:24:22 +0200167 if (wmem < sock->sk->sk_sndbuf / 2)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000168 tx_poll_stop(net);
David Stevens8dd014a2010-07-27 18:52:21 +0300169 hdr_size = vq->vhost_hlen;
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000170 zcopy = vhost_sock_zcopy(sock);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000171
172 for (;;) {
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000173 /* Release DMAs done buffers first */
174 if (zcopy)
175 vhost_zerocopy_signal_used(vq);
176
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000177 head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
178 ARRAY_SIZE(vq->iov),
179 &out, &in,
180 NULL, NULL);
Michael S. Tsirkind5675bd2010-06-24 16:59:59 +0300181 /* On error, stop handling until the next kick. */
Michael S. Tsirkin7b3384f2010-07-01 18:40:12 +0300182 if (unlikely(head < 0))
Michael S. Tsirkind5675bd2010-06-24 16:59:59 +0300183 break;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000184 /* Nothing new? Wait for eventfd to tell us they refilled. */
185 if (head == vq->num) {
Shirley Ma9e380822011-07-20 10:23:12 -0700186 int num_pends;
187
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000188 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 }
Shirley Ma9e380822011-07-20 10:23:12 -0700194 /* 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)) {
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000201 tx_poll_start(net, sock);
202 set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
203 break;
204 }
Michael S. Tsirkin8ea8cf82011-05-20 02:10:54 +0300205 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
206 vhost_disable_notify(&net->dev, vq);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000207 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 }
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000227 /* 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;
Michael S. Tsirkinca8f4fb2012-04-09 00:24:02 +0000242 ubuf->ctx = vq->ubufs;
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000243 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 }
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000251 /* TODO: Check specific error and bomb out unless ENOBUFS? */
252 err = sock->ops->sendmsg(NULL, sock, &msg, len);
253 if (unlikely(err < 0)) {
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000254 if (zcopy) {
255 if (ubufs)
256 vhost_ubuf_put(ubufs);
257 vq->upend_idx = ((unsigned)vq->upend_idx - 1) %
258 UIO_MAXIOV;
259 }
David Stevens8dd014a2010-07-27 18:52:21 +0300260 vhost_discard_vq_desc(vq, 1);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000261 tx_poll_start(net, sock);
262 break;
263 }
264 if (err != len)
Michael S. Tsirkin95c0ec62010-06-24 17:10:25 +0300265 pr_debug("Truncated TX packet: "
266 " len %d != %zd\n", err, len);
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000267 if (!zcopy)
268 vhost_add_used_and_signal(&net->dev, vq, head, 0);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000269 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);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000277}
278
David Stevens8dd014a2010-07-27 18:52:21 +0300279static int peek_head_len(struct sock *sk)
280{
281 struct sk_buff *head;
282 int len = 0;
Jason Wang783e3982011-01-17 16:11:17 +0800283 unsigned long flags;
David Stevens8dd014a2010-07-27 18:52:21 +0300284
Jason Wang783e3982011-01-17 16:11:17 +0800285 spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
David Stevens8dd014a2010-07-27 18:52:21 +0300286 head = skb_peek(&sk->sk_receive_queue);
Basil Gorc53cff52012-05-03 22:55:23 +0000287 if (likely(head)) {
David Stevens8dd014a2010-07-27 18:52:21 +0300288 len = head->len;
Basil Gorc53cff52012-05-03 22:55:23 +0000289 if (vlan_tx_tag_present(head))
290 len += VLAN_HLEN;
291 }
292
Jason Wang783e3982011-01-17 16:11:17 +0800293 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
David Stevens8dd014a2010-07-27 18:52:21 +0300294 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
Jason Wang94249362011-01-17 16:11:08 +0800304 * @quota - headcount quota, 1 for big buffer
David Stevens8dd014a2010-07-27 18:52:21 +0300305 * returns number of buffer heads allocated, negative on error
306 */
307static 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,
Jason Wang94249362011-01-17 16:11:08 +0800312 unsigned *log_num,
313 unsigned int quota)
David Stevens8dd014a2010-07-27 18:52:21 +0300314{
315 unsigned int out, in;
316 int seg = 0;
317 int headcount = 0;
318 unsigned d;
319 int r, nlogs = 0;
320
Jason Wang94249362011-01-17 16:11:08 +0800321 while (datalen > 0 && headcount < quota) {
Jason Wange0e9b402010-09-14 23:53:05 +0800322 if (unlikely(seg >= UIO_MAXIOV)) {
David Stevens8dd014a2010-07-27 18:52:21 +0300323 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;
354err:
355 vhost_discard_vq_desc(vq, headcount);
356 return r;
357}
358
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000359/* Expects to be always run from workqueue - which acts as
360 * read-size critical section for our kind of RCU. */
Jason Wang94249362011-01-17 16:11:08 +0800361static void handle_rx(struct vhost_net *net)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000362{
David Stevens8dd014a2010-07-27 18:52:21 +0300363 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 };
David Stevens8dd014a2010-07-27 18:52:21 +0300374 struct virtio_net_hdr_mrg_rxbuf hdr = {
375 .hdr.flags = 0,
376 .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE
377 };
David Stevens8dd014a2010-07-27 18:52:21 +0300378 size_t total_len = 0;
Jason Wangcfbdab92011-01-17 16:10:59 +0800379 int err, headcount, mergeable;
David Stevens8dd014a2010-07-27 18:52:21 +0300380 size_t vhost_hlen, sock_hlen;
381 size_t vhost_len, sock_len;
Michael S. Tsirkin5e182472011-01-18 13:04:43 +0200382 /* TODO: check that we are running from vhost_worker? */
383 struct socket *sock = rcu_dereference_check(vq->private_data, 1);
Krishna Kumard47effe2011-03-01 17:06:37 +0530384
Michael S. Tsirkinde4d7682011-03-13 23:00:52 +0200385 if (!sock)
David Stevens8dd014a2010-07-27 18:52:21 +0300386 return;
387
David Stevens8dd014a2010-07-27 18:52:21 +0300388 mutex_lock(&vq->mutex);
Michael S. Tsirkin8ea8cf82011-05-20 02:10:54 +0300389 vhost_disable_notify(&net->dev, vq);
David Stevens8dd014a2010-07-27 18:52:21 +0300390 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;
Jason Wangcfbdab92011-01-17 16:10:59 +0800395 mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF);
David Stevens8dd014a2010-07-27 18:52:21 +0300396
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,
Jason Wang94249362011-01-17 16:11:08 +0800401 &in, vq_log, &log,
402 likely(mergeable) ? UIO_MAXIOV : 1);
David Stevens8dd014a2010-07-27 18:52:21 +0300403 /* 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) {
Michael S. Tsirkin8ea8cf82011-05-20 02:10:54 +0300408 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
David Stevens8dd014a2010-07-27 18:52:21 +0300409 /* They have slipped one in as we were
410 * doing that: check again. */
Michael S. Tsirkin8ea8cf82011-05-20 02:10:54 +0300411 vhost_disable_notify(&net->dev, vq);
David Stevens8dd014a2010-07-27 18:52:21 +0300412 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:
Jason Wanga290aec2010-11-29 13:48:40 +0800424 * needed because recvmsg can modify msg_iov. */
David Stevens8dd014a2010-07-27 18:52:21 +0300425 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. */
Jason Wangcfbdab92011-01-17 16:10:59 +0800446 if (likely(mergeable) &&
David Stevens8dd014a2010-07-27 18:52:21 +0300447 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);
David Stevens8dd014a2010-07-27 18:52:21 +0300466}
467
Tejun Heoc23f3442010-06-02 20:40:00 +0200468static void handle_tx_kick(struct vhost_work *work)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000469{
Tejun Heoc23f3442010-06-02 20:40:00 +0200470 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
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000474 handle_tx(net);
475}
476
Tejun Heoc23f3442010-06-02 20:40:00 +0200477static void handle_rx_kick(struct vhost_work *work)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000478{
Tejun Heoc23f3442010-06-02 20:40:00 +0200479 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
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000483 handle_rx(net);
484}
485
Tejun Heoc23f3442010-06-02 20:40:00 +0200486static void handle_tx_net(struct vhost_work *work)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000487{
Tejun Heoc23f3442010-06-02 20:40:00 +0200488 struct vhost_net *net = container_of(work, struct vhost_net,
489 poll[VHOST_NET_VQ_TX].work);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000490 handle_tx(net);
491}
492
Tejun Heoc23f3442010-06-02 20:40:00 +0200493static void handle_rx_net(struct vhost_work *work)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000494{
Tejun Heoc23f3442010-06-02 20:40:00 +0200495 struct vhost_net *net = container_of(work, struct vhost_net,
496 poll[VHOST_NET_VQ_RX].work);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000497 handle_rx(net);
498}
499
500static int vhost_net_open(struct inode *inode, struct file *f)
501{
502 struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
Tejun Heoc23f3442010-06-02 20:40:00 +0200503 struct vhost_dev *dev;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000504 int r;
Tejun Heoc23f3442010-06-02 20:40:00 +0200505
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000506 if (!n)
507 return -ENOMEM;
Tejun Heoc23f3442010-06-02 20:40:00 +0200508
509 dev = &n->dev;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000510 n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick;
511 n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick;
Tejun Heoc23f3442010-06-02 20:40:00 +0200512 r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000513 if (r < 0) {
514 kfree(n);
515 return r;
516 }
517
Tejun Heoc23f3442010-06-02 20:40:00 +0200518 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);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000520 n->tx_poll_state = VHOST_NET_POLL_DISABLED;
521
522 f->private_data = n;
523
524 return 0;
525}
526
527static 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
539static void vhost_net_enable_vq(struct vhost_net *n,
540 struct vhost_virtqueue *vq)
541{
Arnd Bergmann28457ee2010-03-09 19:24:45 +0100542 struct socket *sock;
543
544 sock = rcu_dereference_protected(vq->private_data,
545 lockdep_is_held(&vq->mutex));
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000546 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
555static 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);
Arnd Bergmann28457ee2010-03-09 19:24:45 +0100561 sock = rcu_dereference_protected(vq->private_data,
562 lockdep_is_held(&vq->mutex));
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000563 vhost_net_disable_vq(n, vq);
564 rcu_assign_pointer(vq->private_data, NULL);
565 mutex_unlock(&vq->mutex);
566 return sock;
567}
568
569static 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
576static 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
582static 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
588static 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);
Michael S. Tsirkinea5d4042011-11-27 19:05:58 +0200596 vhost_dev_cleanup(&n->dev, false);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000597 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
608static 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);
Krishna Kumard47effe2011-03-01 17:06:37 +0530616
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000617 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;
636err:
637 fput(sock->file);
638 return ERR_PTR(r);
639}
640
Arnd Bergmann501c7742010-02-18 05:46:50 +0000641static struct socket *get_tap_socket(int fd)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000642{
643 struct file *file = fget(fd);
644 struct socket *sock;
Krishna Kumard47effe2011-03-01 17:06:37 +0530645
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000646 if (!file)
647 return ERR_PTR(-EBADF);
648 sock = tun_get_socket(file);
Arnd Bergmann501c7742010-02-18 05:46:50 +0000649 if (!IS_ERR(sock))
650 return sock;
651 sock = macvtap_get_socket(file);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000652 if (IS_ERR(sock))
653 fput(file);
654 return sock;
655}
656
657static struct socket *get_socket(int fd)
658{
659 struct socket *sock;
Krishna Kumard47effe2011-03-01 17:06:37 +0530660
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000661 /* 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;
Arnd Bergmann501c7742010-02-18 05:46:50 +0000667 sock = get_tap_socket(fd);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000668 if (!IS_ERR(sock))
669 return sock;
670 return ERR_PTR(-ENOTSOCK);
671}
672
673static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
674{
675 struct socket *sock, *oldsock;
676 struct vhost_virtqueue *vq;
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000677 struct vhost_ubuf_ref *ubufs, *oldubufs = NULL;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000678 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;
Jeff Dike1dace8c2010-03-04 16:10:14 -0500695 goto err_vq;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000696 }
697 sock = get_socket(fd);
698 if (IS_ERR(sock)) {
699 r = PTR_ERR(sock);
Jeff Dike1dace8c2010-03-04 16:10:14 -0500700 goto err_vq;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000701 }
702
703 /* start polling new socket */
Arnd Bergmann28457ee2010-03-09 19:24:45 +0100704 oldsock = rcu_dereference_protected(vq->private_data,
705 lockdep_is_held(&vq->mutex));
David S. Miller11fe8832010-07-20 18:25:24 -0700706 if (sock != oldsock) {
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000707 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;
Krishna Kumard47effe2011-03-01 17:06:37 +0530714 vhost_net_disable_vq(n, vq);
715 rcu_assign_pointer(vq->private_data, sock);
716 vhost_net_enable_vq(n, vq);
Jason Wangf59281d2011-06-21 18:04:27 +0800717
718 r = vhost_init_used(vq);
719 if (r)
720 goto err_vq;
Jeff Dikedd1f4072010-03-04 16:10:14 -0500721 }
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000722
Michael S. Tsirkin1680e902010-07-15 15:19:12 +0300723 mutex_unlock(&vq->mutex);
724
Michael S. Tsirkinc047e5f2011-07-20 13:41:31 +0300725 if (oldubufs) {
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000726 vhost_ubuf_put_and_wait(oldubufs);
Michael S. Tsirkinc047e5f2011-07-20 13:41:31 +0300727 mutex_lock(&vq->mutex);
728 vhost_zerocopy_signal_used(vq);
729 mutex_unlock(&vq->mutex);
730 }
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000731
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000732 if (oldsock) {
733 vhost_net_flush_vq(n, index);
734 fput(oldsock->file);
735 }
Jeff Dike1dace8c2010-03-04 16:10:14 -0500736
Michael S. Tsirkin1680e902010-07-15 15:19:12 +0300737 mutex_unlock(&n->dev.mutex);
738 return 0;
739
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000740err_ubufs:
741 fput(sock->file);
Jeff Dike1dace8c2010-03-04 16:10:14 -0500742err_vq:
743 mutex_unlock(&vq->mutex);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000744err:
745 mutex_unlock(&n->dev.mutex);
746 return r;
747}
748
749static 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;
Krishna Kumard47effe2011-03-01 17:06:37 +0530754
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000755 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);
762done:
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
771static int vhost_net_set_features(struct vhost_net *n, u64 features)
772{
David Stevens8dd014a2010-07-27 18:52:21 +0300773 size_t vhost_hlen, sock_hlen, hdr_len;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000774 int i;
David Stevens8dd014a2010-07-27 18:52:21 +0300775
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 }
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000788 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);
David Stevens8dd014a2010-07-27 18:52:21 +0300798 n->vqs[i].vhost_hlen = vhost_hlen;
799 n->vqs[i].sock_hlen = sock_hlen;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000800 mutex_unlock(&n->vqs[i].mutex);
801 }
802 vhost_net_flush(n);
803 mutex_unlock(&n->dev.mutex);
804 return 0;
805}
806
807static 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;
Krishna Kumard47effe2011-03-01 17:06:37 +0530816
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000817 switch (ioctl) {
818 case VHOST_NET_SET_BACKEND:
Takuya Yoshikawad3553a52010-05-27 19:01:58 +0900819 if (copy_from_user(&backend, argp, sizeof backend))
820 return -EFAULT;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000821 return vhost_net_set_backend(n, backend.index, backend.fd);
822 case VHOST_GET_FEATURES:
823 features = VHOST_FEATURES;
Takuya Yoshikawad3553a52010-05-27 19:01:58 +0900824 if (copy_to_user(featurep, &features, sizeof features))
825 return -EFAULT;
826 return 0;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000827 case VHOST_SET_FEATURES:
Takuya Yoshikawad3553a52010-05-27 19:01:58 +0900828 if (copy_from_user(&features, featurep, sizeof features))
829 return -EFAULT;
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000830 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
845static 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
Tobias Klauser373a83a2010-05-17 15:12:49 +0200852static const struct file_operations vhost_net_fops = {
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000853 .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,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200860 .llseek = noop_llseek,
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000861};
862
863static struct miscdevice vhost_net_misc = {
stephen hemminger7c7c7f02012-01-11 19:30:38 +0000864 .minor = VHOST_NET_MINOR,
865 .name = "vhost-net",
866 .fops = &vhost_net_fops,
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000867};
868
Christoph Hellwiga8d37822010-04-13 14:11:25 -0400869static int vhost_net_init(void)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000870{
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000871 if (experimental_zcopytx)
872 vhost_enable_zcopy(VHOST_NET_VQ_TX);
Tejun Heoc23f3442010-06-02 20:40:00 +0200873 return misc_register(&vhost_net_misc);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000874}
875module_init(vhost_net_init);
876
Christoph Hellwiga8d37822010-04-13 14:11:25 -0400877static void vhost_net_exit(void)
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000878{
879 misc_deregister(&vhost_net_misc);
Michael S. Tsirkin3a4d5c92010-01-14 06:17:27 +0000880}
881module_exit(vhost_net_exit);
882
883MODULE_VERSION("0.0.1");
884MODULE_LICENSE("GPL v2");
885MODULE_AUTHOR("Michael S. Tsirkin");
886MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
stephen hemminger7c7c7f02012-01-11 19:30:38 +0000887MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR);
888MODULE_ALIAS("devname:vhost-net");