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Michael S. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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 Gorc53cff5e2012-05-03 22:55:23 +000027#include <linux/if_vlan.h>
Michael S. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000161 return;
Sridhar Samudrala39286fa2010-02-28 19:39:16 +0200162 }
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000163
Michael S. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000166
Michael S. Tsirkin0e255572010-03-08 23:24:22 +0200167 if (wmem < sock->sk->sk_sndbuf / 2)
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000168 tx_poll_stop(net);
David Stevens8dd014a2010-07-27 18:52:21 +0300169 hdr_size = vq->vhost_hlen;
Jason Wangc460f052012-05-02 11:42:23 +0800170 zcopy = vq->ubufs;
Michael S. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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. Tsirkin3a4d5c94e2010-01-14 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);
Jason Wangdbf34202012-05-02 11:42:32 +0800261 if (err == -EAGAIN || err == -ENOBUFS)
262 tx_poll_start(net, sock);
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000263 break;
264 }
265 if (err != len)
Michael S. Tsirkin95c0ec62010-06-24 17:10:25 +0300266 pr_debug("Truncated TX packet: "
267 " len %d != %zd\n", err, len);
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000268 if (!zcopy)
269 vhost_add_used_and_signal(&net->dev, vq, head, 0);
Jason Wangc8fb2172012-05-02 11:42:41 +0800270 else
271 vhost_zerocopy_signal_used(vq);
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000272 total_len += len;
273 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
274 vhost_poll_queue(&vq->poll);
275 break;
276 }
277 }
278
279 mutex_unlock(&vq->mutex);
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000280}
281
David Stevens8dd014a2010-07-27 18:52:21 +0300282static int peek_head_len(struct sock *sk)
283{
284 struct sk_buff *head;
285 int len = 0;
Jason Wang783e3982011-01-17 16:11:17 +0800286 unsigned long flags;
David Stevens8dd014a2010-07-27 18:52:21 +0300287
Jason Wang783e3982011-01-17 16:11:17 +0800288 spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
David Stevens8dd014a2010-07-27 18:52:21 +0300289 head = skb_peek(&sk->sk_receive_queue);
Basil Gorc53cff5e2012-05-03 22:55:23 +0000290 if (likely(head)) {
David Stevens8dd014a2010-07-27 18:52:21 +0300291 len = head->len;
Basil Gorc53cff5e2012-05-03 22:55:23 +0000292 if (vlan_tx_tag_present(head))
293 len += VLAN_HLEN;
294 }
295
Jason Wang783e3982011-01-17 16:11:17 +0800296 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
David Stevens8dd014a2010-07-27 18:52:21 +0300297 return len;
298}
299
300/* This is a multi-buffer version of vhost_get_desc, that works if
301 * vq has read descriptors only.
302 * @vq - the relevant virtqueue
303 * @datalen - data length we'll be reading
304 * @iovcount - returned count of io vectors we fill
305 * @log - vhost log
306 * @log_num - log offset
Jason Wang94249362011-01-17 16:11:08 +0800307 * @quota - headcount quota, 1 for big buffer
David Stevens8dd014a2010-07-27 18:52:21 +0300308 * returns number of buffer heads allocated, negative on error
309 */
310static int get_rx_bufs(struct vhost_virtqueue *vq,
311 struct vring_used_elem *heads,
312 int datalen,
313 unsigned *iovcount,
314 struct vhost_log *log,
Jason Wang94249362011-01-17 16:11:08 +0800315 unsigned *log_num,
316 unsigned int quota)
David Stevens8dd014a2010-07-27 18:52:21 +0300317{
318 unsigned int out, in;
319 int seg = 0;
320 int headcount = 0;
321 unsigned d;
322 int r, nlogs = 0;
323
Jason Wang94249362011-01-17 16:11:08 +0800324 while (datalen > 0 && headcount < quota) {
Jason Wange0e9b402010-09-14 23:53:05 +0800325 if (unlikely(seg >= UIO_MAXIOV)) {
David Stevens8dd014a2010-07-27 18:52:21 +0300326 r = -ENOBUFS;
327 goto err;
328 }
329 d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg,
330 ARRAY_SIZE(vq->iov) - seg, &out,
331 &in, log, log_num);
332 if (d == vq->num) {
333 r = 0;
334 goto err;
335 }
336 if (unlikely(out || in <= 0)) {
337 vq_err(vq, "unexpected descriptor format for RX: "
338 "out %d, in %d\n", out, in);
339 r = -EINVAL;
340 goto err;
341 }
342 if (unlikely(log)) {
343 nlogs += *log_num;
344 log += *log_num;
345 }
346 heads[headcount].id = d;
347 heads[headcount].len = iov_length(vq->iov + seg, in);
348 datalen -= heads[headcount].len;
349 ++headcount;
350 seg += in;
351 }
352 heads[headcount - 1].len += datalen;
353 *iovcount = seg;
354 if (unlikely(log))
355 *log_num = nlogs;
356 return headcount;
357err:
358 vhost_discard_vq_desc(vq, headcount);
359 return r;
360}
361
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000362/* Expects to be always run from workqueue - which acts as
363 * read-size critical section for our kind of RCU. */
Jason Wang94249362011-01-17 16:11:08 +0800364static void handle_rx(struct vhost_net *net)
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000365{
David Stevens8dd014a2010-07-27 18:52:21 +0300366 struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
367 unsigned uninitialized_var(in), log;
368 struct vhost_log *vq_log;
369 struct msghdr msg = {
370 .msg_name = NULL,
371 .msg_namelen = 0,
372 .msg_control = NULL, /* FIXME: get and handle RX aux data. */
373 .msg_controllen = 0,
374 .msg_iov = vq->iov,
375 .msg_flags = MSG_DONTWAIT,
376 };
David Stevens8dd014a2010-07-27 18:52:21 +0300377 struct virtio_net_hdr_mrg_rxbuf hdr = {
378 .hdr.flags = 0,
379 .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE
380 };
David Stevens8dd014a2010-07-27 18:52:21 +0300381 size_t total_len = 0;
Jason Wangcfbdab92011-01-17 16:10:59 +0800382 int err, headcount, mergeable;
David Stevens8dd014a2010-07-27 18:52:21 +0300383 size_t vhost_hlen, sock_hlen;
384 size_t vhost_len, sock_len;
Michael S. Tsirkin5e182472011-01-18 13:04:43 +0200385 /* TODO: check that we are running from vhost_worker? */
386 struct socket *sock = rcu_dereference_check(vq->private_data, 1);
Krishna Kumard47effe2011-03-01 17:06:37 +0530387
Michael S. Tsirkinde4d7682011-03-13 23:00:52 +0200388 if (!sock)
David Stevens8dd014a2010-07-27 18:52:21 +0300389 return;
390
David Stevens8dd014a2010-07-27 18:52:21 +0300391 mutex_lock(&vq->mutex);
Michael S. Tsirkin8ea8cf82011-05-20 02:10:54 +0300392 vhost_disable_notify(&net->dev, vq);
David Stevens8dd014a2010-07-27 18:52:21 +0300393 vhost_hlen = vq->vhost_hlen;
394 sock_hlen = vq->sock_hlen;
395
396 vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
397 vq->log : NULL;
Jason Wangcfbdab92011-01-17 16:10:59 +0800398 mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF);
David Stevens8dd014a2010-07-27 18:52:21 +0300399
400 while ((sock_len = peek_head_len(sock->sk))) {
401 sock_len += sock_hlen;
402 vhost_len = sock_len + vhost_hlen;
403 headcount = get_rx_bufs(vq, vq->heads, vhost_len,
Jason Wang94249362011-01-17 16:11:08 +0800404 &in, vq_log, &log,
405 likely(mergeable) ? UIO_MAXIOV : 1);
David Stevens8dd014a2010-07-27 18:52:21 +0300406 /* On error, stop handling until the next kick. */
407 if (unlikely(headcount < 0))
408 break;
409 /* OK, now we need to know about added descriptors. */
410 if (!headcount) {
Michael S. Tsirkin8ea8cf82011-05-20 02:10:54 +0300411 if (unlikely(vhost_enable_notify(&net->dev, vq))) {
David Stevens8dd014a2010-07-27 18:52:21 +0300412 /* They have slipped one in as we were
413 * doing that: check again. */
Michael S. Tsirkin8ea8cf82011-05-20 02:10:54 +0300414 vhost_disable_notify(&net->dev, vq);
David Stevens8dd014a2010-07-27 18:52:21 +0300415 continue;
416 }
417 /* Nothing new? Wait for eventfd to tell us
418 * they refilled. */
419 break;
420 }
421 /* We don't need to be notified again. */
422 if (unlikely((vhost_hlen)))
423 /* Skip header. TODO: support TSO. */
424 move_iovec_hdr(vq->iov, vq->hdr, vhost_hlen, in);
425 else
426 /* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
Jason Wanga290aec2010-11-29 13:48:40 +0800427 * needed because recvmsg can modify msg_iov. */
David Stevens8dd014a2010-07-27 18:52:21 +0300428 copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in);
429 msg.msg_iovlen = in;
430 err = sock->ops->recvmsg(NULL, sock, &msg,
431 sock_len, MSG_DONTWAIT | MSG_TRUNC);
432 /* Userspace might have consumed the packet meanwhile:
433 * it's not supposed to do this usually, but might be hard
434 * to prevent. Discard data we got (if any) and keep going. */
435 if (unlikely(err != sock_len)) {
436 pr_debug("Discarded rx packet: "
437 " len %d, expected %zd\n", err, sock_len);
438 vhost_discard_vq_desc(vq, headcount);
439 continue;
440 }
441 if (unlikely(vhost_hlen) &&
442 memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0,
443 vhost_hlen)) {
444 vq_err(vq, "Unable to write vnet_hdr at addr %p\n",
445 vq->iov->iov_base);
446 break;
447 }
448 /* TODO: Should check and handle checksum. */
Jason Wangcfbdab92011-01-17 16:10:59 +0800449 if (likely(mergeable) &&
David Stevens8dd014a2010-07-27 18:52:21 +0300450 memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount,
451 offsetof(typeof(hdr), num_buffers),
452 sizeof hdr.num_buffers)) {
453 vq_err(vq, "Failed num_buffers write");
454 vhost_discard_vq_desc(vq, headcount);
455 break;
456 }
457 vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
458 headcount);
459 if (unlikely(vq_log))
460 vhost_log_write(vq, vq_log, log, vhost_len);
461 total_len += vhost_len;
462 if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
463 vhost_poll_queue(&vq->poll);
464 break;
465 }
466 }
467
468 mutex_unlock(&vq->mutex);
David Stevens8dd014a2010-07-27 18:52:21 +0300469}
470
Tejun Heoc23f34452010-06-02 20:40:00 +0200471static void handle_tx_kick(struct vhost_work *work)
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000472{
Tejun Heoc23f34452010-06-02 20:40:00 +0200473 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
474 poll.work);
475 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
476
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000477 handle_tx(net);
478}
479
Tejun Heoc23f34452010-06-02 20:40:00 +0200480static void handle_rx_kick(struct vhost_work *work)
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000481{
Tejun Heoc23f34452010-06-02 20:40:00 +0200482 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
483 poll.work);
484 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
485
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000486 handle_rx(net);
487}
488
Tejun Heoc23f34452010-06-02 20:40:00 +0200489static void handle_tx_net(struct vhost_work *work)
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000490{
Tejun Heoc23f34452010-06-02 20:40:00 +0200491 struct vhost_net *net = container_of(work, struct vhost_net,
492 poll[VHOST_NET_VQ_TX].work);
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000493 handle_tx(net);
494}
495
Tejun Heoc23f34452010-06-02 20:40:00 +0200496static void handle_rx_net(struct vhost_work *work)
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000497{
Tejun Heoc23f34452010-06-02 20:40:00 +0200498 struct vhost_net *net = container_of(work, struct vhost_net,
499 poll[VHOST_NET_VQ_RX].work);
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000500 handle_rx(net);
501}
502
503static int vhost_net_open(struct inode *inode, struct file *f)
504{
505 struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
Tejun Heoc23f34452010-06-02 20:40:00 +0200506 struct vhost_dev *dev;
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000507 int r;
Tejun Heoc23f34452010-06-02 20:40:00 +0200508
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000509 if (!n)
510 return -ENOMEM;
Tejun Heoc23f34452010-06-02 20:40:00 +0200511
512 dev = &n->dev;
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000513 n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick;
514 n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick;
Tejun Heoc23f34452010-06-02 20:40:00 +0200515 r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX);
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000516 if (r < 0) {
517 kfree(n);
518 return r;
519 }
520
Tejun Heoc23f34452010-06-02 20:40:00 +0200521 vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
522 vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000523 n->tx_poll_state = VHOST_NET_POLL_DISABLED;
524
525 f->private_data = n;
526
527 return 0;
528}
529
530static void vhost_net_disable_vq(struct vhost_net *n,
531 struct vhost_virtqueue *vq)
532{
533 if (!vq->private_data)
534 return;
535 if (vq == n->vqs + VHOST_NET_VQ_TX) {
536 tx_poll_stop(n);
537 n->tx_poll_state = VHOST_NET_POLL_DISABLED;
538 } else
539 vhost_poll_stop(n->poll + VHOST_NET_VQ_RX);
540}
541
542static void vhost_net_enable_vq(struct vhost_net *n,
543 struct vhost_virtqueue *vq)
544{
Arnd Bergmann28457ee2010-03-09 19:24:45 +0100545 struct socket *sock;
546
547 sock = rcu_dereference_protected(vq->private_data,
548 lockdep_is_held(&vq->mutex));
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000549 if (!sock)
550 return;
551 if (vq == n->vqs + VHOST_NET_VQ_TX) {
552 n->tx_poll_state = VHOST_NET_POLL_STOPPED;
553 tx_poll_start(n, sock);
554 } else
555 vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file);
556}
557
558static struct socket *vhost_net_stop_vq(struct vhost_net *n,
559 struct vhost_virtqueue *vq)
560{
561 struct socket *sock;
562
563 mutex_lock(&vq->mutex);
Arnd Bergmann28457ee2010-03-09 19:24:45 +0100564 sock = rcu_dereference_protected(vq->private_data,
565 lockdep_is_held(&vq->mutex));
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000566 vhost_net_disable_vq(n, vq);
567 rcu_assign_pointer(vq->private_data, NULL);
568 mutex_unlock(&vq->mutex);
569 return sock;
570}
571
572static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
573 struct socket **rx_sock)
574{
575 *tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX);
576 *rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX);
577}
578
579static void vhost_net_flush_vq(struct vhost_net *n, int index)
580{
581 vhost_poll_flush(n->poll + index);
582 vhost_poll_flush(&n->dev.vqs[index].poll);
583}
584
585static void vhost_net_flush(struct vhost_net *n)
586{
587 vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
588 vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
589}
590
591static int vhost_net_release(struct inode *inode, struct file *f)
592{
593 struct vhost_net *n = f->private_data;
594 struct socket *tx_sock;
595 struct socket *rx_sock;
596
597 vhost_net_stop(n, &tx_sock, &rx_sock);
598 vhost_net_flush(n);
Michael S. Tsirkinea5d4042011-11-27 19:05:58 +0200599 vhost_dev_cleanup(&n->dev, false);
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000600 if (tx_sock)
601 fput(tx_sock->file);
602 if (rx_sock)
603 fput(rx_sock->file);
604 /* We do an extra flush before freeing memory,
605 * since jobs can re-queue themselves. */
606 vhost_net_flush(n);
607 kfree(n);
608 return 0;
609}
610
611static struct socket *get_raw_socket(int fd)
612{
613 struct {
614 struct sockaddr_ll sa;
615 char buf[MAX_ADDR_LEN];
616 } uaddr;
617 int uaddr_len = sizeof uaddr, r;
618 struct socket *sock = sockfd_lookup(fd, &r);
Krishna Kumard47effe2011-03-01 17:06:37 +0530619
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000620 if (!sock)
621 return ERR_PTR(-ENOTSOCK);
622
623 /* Parameter checking */
624 if (sock->sk->sk_type != SOCK_RAW) {
625 r = -ESOCKTNOSUPPORT;
626 goto err;
627 }
628
629 r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa,
630 &uaddr_len, 0);
631 if (r)
632 goto err;
633
634 if (uaddr.sa.sll_family != AF_PACKET) {
635 r = -EPFNOSUPPORT;
636 goto err;
637 }
638 return sock;
639err:
640 fput(sock->file);
641 return ERR_PTR(r);
642}
643
Arnd Bergmann501c7742010-02-18 05:46:50 +0000644static struct socket *get_tap_socket(int fd)
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000645{
646 struct file *file = fget(fd);
647 struct socket *sock;
Krishna Kumard47effe2011-03-01 17:06:37 +0530648
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000649 if (!file)
650 return ERR_PTR(-EBADF);
651 sock = tun_get_socket(file);
Arnd Bergmann501c7742010-02-18 05:46:50 +0000652 if (!IS_ERR(sock))
653 return sock;
654 sock = macvtap_get_socket(file);
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000655 if (IS_ERR(sock))
656 fput(file);
657 return sock;
658}
659
660static struct socket *get_socket(int fd)
661{
662 struct socket *sock;
Krishna Kumard47effe2011-03-01 17:06:37 +0530663
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000664 /* special case to disable backend */
665 if (fd == -1)
666 return NULL;
667 sock = get_raw_socket(fd);
668 if (!IS_ERR(sock))
669 return sock;
Arnd Bergmann501c7742010-02-18 05:46:50 +0000670 sock = get_tap_socket(fd);
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000671 if (!IS_ERR(sock))
672 return sock;
673 return ERR_PTR(-ENOTSOCK);
674}
675
676static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
677{
678 struct socket *sock, *oldsock;
679 struct vhost_virtqueue *vq;
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000680 struct vhost_ubuf_ref *ubufs, *oldubufs = NULL;
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000681 int r;
682
683 mutex_lock(&n->dev.mutex);
684 r = vhost_dev_check_owner(&n->dev);
685 if (r)
686 goto err;
687
688 if (index >= VHOST_NET_VQ_MAX) {
689 r = -ENOBUFS;
690 goto err;
691 }
692 vq = n->vqs + index;
693 mutex_lock(&vq->mutex);
694
695 /* Verify that ring has been setup correctly. */
696 if (!vhost_vq_access_ok(vq)) {
697 r = -EFAULT;
Jeff Dike1dace8c2010-03-04 16:10:14 -0500698 goto err_vq;
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000699 }
700 sock = get_socket(fd);
701 if (IS_ERR(sock)) {
702 r = PTR_ERR(sock);
Jeff Dike1dace8c2010-03-04 16:10:14 -0500703 goto err_vq;
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000704 }
705
706 /* start polling new socket */
Arnd Bergmann28457ee2010-03-09 19:24:45 +0100707 oldsock = rcu_dereference_protected(vq->private_data,
708 lockdep_is_held(&vq->mutex));
David S. Miller11fe8832010-07-20 18:25:24 -0700709 if (sock != oldsock) {
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000710 ubufs = vhost_ubuf_alloc(vq, sock && vhost_sock_zcopy(sock));
711 if (IS_ERR(ubufs)) {
712 r = PTR_ERR(ubufs);
713 goto err_ubufs;
714 }
715 oldubufs = vq->ubufs;
716 vq->ubufs = ubufs;
Krishna Kumard47effe2011-03-01 17:06:37 +0530717 vhost_net_disable_vq(n, vq);
718 rcu_assign_pointer(vq->private_data, sock);
719 vhost_net_enable_vq(n, vq);
Jason Wangf59281d2011-06-21 18:04:27 +0800720
721 r = vhost_init_used(vq);
722 if (r)
723 goto err_vq;
Jeff Dikedd1f4072010-03-04 16:10:14 -0500724 }
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000725
Michael S. Tsirkin1680e902010-07-15 15:19:12 +0300726 mutex_unlock(&vq->mutex);
727
Michael S. Tsirkinc047e5f2011-07-20 13:41:31 +0300728 if (oldubufs) {
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000729 vhost_ubuf_put_and_wait(oldubufs);
Michael S. Tsirkinc047e5f2011-07-20 13:41:31 +0300730 mutex_lock(&vq->mutex);
731 vhost_zerocopy_signal_used(vq);
732 mutex_unlock(&vq->mutex);
733 }
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000734
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000735 if (oldsock) {
736 vhost_net_flush_vq(n, index);
737 fput(oldsock->file);
738 }
Jeff Dike1dace8c2010-03-04 16:10:14 -0500739
Michael S. Tsirkin1680e902010-07-15 15:19:12 +0300740 mutex_unlock(&n->dev.mutex);
741 return 0;
742
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000743err_ubufs:
744 fput(sock->file);
Jeff Dike1dace8c2010-03-04 16:10:14 -0500745err_vq:
746 mutex_unlock(&vq->mutex);
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000747err:
748 mutex_unlock(&n->dev.mutex);
749 return r;
750}
751
752static long vhost_net_reset_owner(struct vhost_net *n)
753{
754 struct socket *tx_sock = NULL;
755 struct socket *rx_sock = NULL;
756 long err;
Krishna Kumard47effe2011-03-01 17:06:37 +0530757
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000758 mutex_lock(&n->dev.mutex);
759 err = vhost_dev_check_owner(&n->dev);
760 if (err)
761 goto done;
762 vhost_net_stop(n, &tx_sock, &rx_sock);
763 vhost_net_flush(n);
764 err = vhost_dev_reset_owner(&n->dev);
765done:
766 mutex_unlock(&n->dev.mutex);
767 if (tx_sock)
768 fput(tx_sock->file);
769 if (rx_sock)
770 fput(rx_sock->file);
771 return err;
772}
773
774static int vhost_net_set_features(struct vhost_net *n, u64 features)
775{
David Stevens8dd014a2010-07-27 18:52:21 +0300776 size_t vhost_hlen, sock_hlen, hdr_len;
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000777 int i;
David Stevens8dd014a2010-07-27 18:52:21 +0300778
779 hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
780 sizeof(struct virtio_net_hdr_mrg_rxbuf) :
781 sizeof(struct virtio_net_hdr);
782 if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
783 /* vhost provides vnet_hdr */
784 vhost_hlen = hdr_len;
785 sock_hlen = 0;
786 } else {
787 /* socket provides vnet_hdr */
788 vhost_hlen = 0;
789 sock_hlen = hdr_len;
790 }
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000791 mutex_lock(&n->dev.mutex);
792 if ((features & (1 << VHOST_F_LOG_ALL)) &&
793 !vhost_log_access_ok(&n->dev)) {
794 mutex_unlock(&n->dev.mutex);
795 return -EFAULT;
796 }
797 n->dev.acked_features = features;
798 smp_wmb();
799 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
800 mutex_lock(&n->vqs[i].mutex);
David Stevens8dd014a2010-07-27 18:52:21 +0300801 n->vqs[i].vhost_hlen = vhost_hlen;
802 n->vqs[i].sock_hlen = sock_hlen;
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000803 mutex_unlock(&n->vqs[i].mutex);
804 }
805 vhost_net_flush(n);
806 mutex_unlock(&n->dev.mutex);
807 return 0;
808}
809
810static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
811 unsigned long arg)
812{
813 struct vhost_net *n = f->private_data;
814 void __user *argp = (void __user *)arg;
815 u64 __user *featurep = argp;
816 struct vhost_vring_file backend;
817 u64 features;
818 int r;
Krishna Kumard47effe2011-03-01 17:06:37 +0530819
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000820 switch (ioctl) {
821 case VHOST_NET_SET_BACKEND:
Takuya Yoshikawad3553a52010-05-27 19:01:58 +0900822 if (copy_from_user(&backend, argp, sizeof backend))
823 return -EFAULT;
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000824 return vhost_net_set_backend(n, backend.index, backend.fd);
825 case VHOST_GET_FEATURES:
Stefan Hajnoczi0dd05a32012-07-21 06:55:36 +0000826 features = VHOST_NET_FEATURES;
Takuya Yoshikawad3553a52010-05-27 19:01:58 +0900827 if (copy_to_user(featurep, &features, sizeof features))
828 return -EFAULT;
829 return 0;
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000830 case VHOST_SET_FEATURES:
Takuya Yoshikawad3553a52010-05-27 19:01:58 +0900831 if (copy_from_user(&features, featurep, sizeof features))
832 return -EFAULT;
Stefan Hajnoczi0dd05a32012-07-21 06:55:36 +0000833 if (features & ~VHOST_NET_FEATURES)
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000834 return -EOPNOTSUPP;
835 return vhost_net_set_features(n, features);
836 case VHOST_RESET_OWNER:
837 return vhost_net_reset_owner(n);
838 default:
839 mutex_lock(&n->dev.mutex);
840 r = vhost_dev_ioctl(&n->dev, ioctl, arg);
841 vhost_net_flush(n);
842 mutex_unlock(&n->dev.mutex);
843 return r;
844 }
845}
846
847#ifdef CONFIG_COMPAT
848static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
849 unsigned long arg)
850{
851 return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
852}
853#endif
854
Tobias Klauser373a83a2010-05-17 15:12:49 +0200855static const struct file_operations vhost_net_fops = {
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000856 .owner = THIS_MODULE,
857 .release = vhost_net_release,
858 .unlocked_ioctl = vhost_net_ioctl,
859#ifdef CONFIG_COMPAT
860 .compat_ioctl = vhost_net_compat_ioctl,
861#endif
862 .open = vhost_net_open,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200863 .llseek = noop_llseek,
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000864};
865
866static struct miscdevice vhost_net_misc = {
stephen hemminger7c7c7f02012-01-11 19:30:38 +0000867 .minor = VHOST_NET_MINOR,
868 .name = "vhost-net",
869 .fops = &vhost_net_fops,
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000870};
871
Christoph Hellwiga8d37822010-04-13 14:11:25 -0400872static int vhost_net_init(void)
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000873{
Michael S. Tsirkinbab632d2011-07-18 03:48:46 +0000874 if (experimental_zcopytx)
875 vhost_enable_zcopy(VHOST_NET_VQ_TX);
Tejun Heoc23f34452010-06-02 20:40:00 +0200876 return misc_register(&vhost_net_misc);
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000877}
878module_init(vhost_net_init);
879
Christoph Hellwiga8d37822010-04-13 14:11:25 -0400880static void vhost_net_exit(void)
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000881{
882 misc_deregister(&vhost_net_misc);
Michael S. Tsirkin3a4d5c94e2010-01-14 06:17:27 +0000883}
884module_exit(vhost_net_exit);
885
886MODULE_VERSION("0.0.1");
887MODULE_LICENSE("GPL v2");
888MODULE_AUTHOR("Michael S. Tsirkin");
889MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
stephen hemminger7c7c7f02012-01-11 19:30:38 +0000890MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR);
891MODULE_ALIAS("devname:vhost-net");