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1 | /* | |
2 | * xen paravirt network card backend | |
3 | * | |
4 | * (c) Gerd Hoffmann <kraxel@redhat.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; under version 2 of the License. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License along | |
16 | * with this program; if not, see <http://www.gnu.org/licenses/>. | |
17 | * | |
18 | * Contributions after 2012-01-13 are licensed under the terms of the | |
19 | * GNU GPL, version 2 or (at your option) any later version. | |
20 | */ | |
21 | ||
22 | #include <stdio.h> | |
23 | #include <stdlib.h> | |
24 | #include <stdarg.h> | |
25 | #include <string.h> | |
26 | #include <unistd.h> | |
27 | #include <signal.h> | |
28 | #include <inttypes.h> | |
29 | #include <fcntl.h> | |
30 | #include <errno.h> | |
31 | #include <sys/socket.h> | |
32 | #include <sys/ioctl.h> | |
33 | #include <sys/types.h> | |
34 | #include <sys/stat.h> | |
35 | #include <sys/mman.h> | |
36 | #include <sys/wait.h> | |
37 | ||
38 | #include "hw/hw.h" | |
39 | #include "net/net.h" | |
40 | #include "net/checksum.h" | |
41 | #include "net/util.h" | |
42 | #include "hw/xen/xen_backend.h" | |
43 | ||
44 | #include <xen/io/netif.h> | |
45 | ||
46 | /* ------------------------------------------------------------- */ | |
47 | ||
48 | struct XenNetDev { | |
49 | struct XenDevice xendev; /* must be first */ | |
50 | char *mac; | |
51 | int tx_work; | |
52 | int tx_ring_ref; | |
53 | int rx_ring_ref; | |
54 | struct netif_tx_sring *txs; | |
55 | struct netif_rx_sring *rxs; | |
56 | netif_tx_back_ring_t tx_ring; | |
57 | netif_rx_back_ring_t rx_ring; | |
58 | NICConf conf; | |
59 | NICState *nic; | |
60 | }; | |
61 | ||
62 | /* ------------------------------------------------------------- */ | |
63 | ||
64 | static void net_tx_response(struct XenNetDev *netdev, netif_tx_request_t *txp, int8_t st) | |
65 | { | |
66 | RING_IDX i = netdev->tx_ring.rsp_prod_pvt; | |
67 | netif_tx_response_t *resp; | |
68 | int notify; | |
69 | ||
70 | resp = RING_GET_RESPONSE(&netdev->tx_ring, i); | |
71 | resp->id = txp->id; | |
72 | resp->status = st; | |
73 | ||
74 | #if 0 | |
75 | if (txp->flags & NETTXF_extra_info) { | |
76 | RING_GET_RESPONSE(&netdev->tx_ring, ++i)->status = NETIF_RSP_NULL; | |
77 | } | |
78 | #endif | |
79 | ||
80 | netdev->tx_ring.rsp_prod_pvt = ++i; | |
81 | RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->tx_ring, notify); | |
82 | if (notify) { | |
83 | xen_be_send_notify(&netdev->xendev); | |
84 | } | |
85 | ||
86 | if (i == netdev->tx_ring.req_cons) { | |
87 | int more_to_do; | |
88 | RING_FINAL_CHECK_FOR_REQUESTS(&netdev->tx_ring, more_to_do); | |
89 | if (more_to_do) { | |
90 | netdev->tx_work++; | |
91 | } | |
92 | } | |
93 | } | |
94 | ||
95 | static void net_tx_error(struct XenNetDev *netdev, netif_tx_request_t *txp, RING_IDX end) | |
96 | { | |
97 | #if 0 | |
98 | /* | |
99 | * Hmm, why netback fails everything in the ring? | |
100 | * Should we do that even when not supporting SG and TSO? | |
101 | */ | |
102 | RING_IDX cons = netdev->tx_ring.req_cons; | |
103 | ||
104 | do { | |
105 | make_tx_response(netif, txp, NETIF_RSP_ERROR); | |
106 | if (cons >= end) { | |
107 | break; | |
108 | } | |
109 | txp = RING_GET_REQUEST(&netdev->tx_ring, cons++); | |
110 | } while (1); | |
111 | netdev->tx_ring.req_cons = cons; | |
112 | netif_schedule_work(netif); | |
113 | netif_put(netif); | |
114 | #else | |
115 | net_tx_response(netdev, txp, NETIF_RSP_ERROR); | |
116 | #endif | |
117 | } | |
118 | ||
119 | static void net_tx_packets(struct XenNetDev *netdev) | |
120 | { | |
121 | netif_tx_request_t txreq; | |
122 | RING_IDX rc, rp; | |
123 | void *page; | |
124 | void *tmpbuf = NULL; | |
125 | ||
126 | for (;;) { | |
127 | rc = netdev->tx_ring.req_cons; | |
128 | rp = netdev->tx_ring.sring->req_prod; | |
129 | xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ | |
130 | ||
131 | while ((rc != rp)) { | |
132 | if (RING_REQUEST_CONS_OVERFLOW(&netdev->tx_ring, rc)) { | |
133 | break; | |
134 | } | |
135 | memcpy(&txreq, RING_GET_REQUEST(&netdev->tx_ring, rc), sizeof(txreq)); | |
136 | netdev->tx_ring.req_cons = ++rc; | |
137 | ||
138 | #if 1 | |
139 | /* should not happen in theory, we don't announce the * | |
140 | * feature-{sg,gso,whatelse} flags in xenstore (yet?) */ | |
141 | if (txreq.flags & NETTXF_extra_info) { | |
142 | xen_be_printf(&netdev->xendev, 0, "FIXME: extra info flag\n"); | |
143 | net_tx_error(netdev, &txreq, rc); | |
144 | continue; | |
145 | } | |
146 | if (txreq.flags & NETTXF_more_data) { | |
147 | xen_be_printf(&netdev->xendev, 0, "FIXME: more data flag\n"); | |
148 | net_tx_error(netdev, &txreq, rc); | |
149 | continue; | |
150 | } | |
151 | #endif | |
152 | ||
153 | if (txreq.size < 14) { | |
154 | xen_be_printf(&netdev->xendev, 0, "bad packet size: %d\n", txreq.size); | |
155 | net_tx_error(netdev, &txreq, rc); | |
156 | continue; | |
157 | } | |
158 | ||
159 | if ((txreq.offset + txreq.size) > XC_PAGE_SIZE) { | |
160 | xen_be_printf(&netdev->xendev, 0, "error: page crossing\n"); | |
161 | net_tx_error(netdev, &txreq, rc); | |
162 | continue; | |
163 | } | |
164 | ||
165 | xen_be_printf(&netdev->xendev, 3, "tx packet ref %d, off %d, len %d, flags 0x%x%s%s%s%s\n", | |
166 | txreq.gref, txreq.offset, txreq.size, txreq.flags, | |
167 | (txreq.flags & NETTXF_csum_blank) ? " csum_blank" : "", | |
168 | (txreq.flags & NETTXF_data_validated) ? " data_validated" : "", | |
169 | (txreq.flags & NETTXF_more_data) ? " more_data" : "", | |
170 | (txreq.flags & NETTXF_extra_info) ? " extra_info" : ""); | |
171 | ||
172 | page = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, | |
173 | netdev->xendev.dom, | |
174 | txreq.gref, PROT_READ); | |
175 | if (page == NULL) { | |
176 | xen_be_printf(&netdev->xendev, 0, "error: tx gref dereference failed (%d)\n", | |
177 | txreq.gref); | |
178 | net_tx_error(netdev, &txreq, rc); | |
179 | continue; | |
180 | } | |
181 | if (txreq.flags & NETTXF_csum_blank) { | |
182 | /* have read-only mapping -> can't fill checksum in-place */ | |
183 | if (!tmpbuf) { | |
184 | tmpbuf = g_malloc(XC_PAGE_SIZE); | |
185 | } | |
186 | memcpy(tmpbuf, page + txreq.offset, txreq.size); | |
187 | net_checksum_calculate(tmpbuf, txreq.size); | |
188 | qemu_send_packet(qemu_get_queue(netdev->nic), tmpbuf, | |
189 | txreq.size); | |
190 | } else { | |
191 | qemu_send_packet(qemu_get_queue(netdev->nic), | |
192 | page + txreq.offset, txreq.size); | |
193 | } | |
194 | xc_gnttab_munmap(netdev->xendev.gnttabdev, page, 1); | |
195 | net_tx_response(netdev, &txreq, NETIF_RSP_OKAY); | |
196 | } | |
197 | if (!netdev->tx_work) { | |
198 | break; | |
199 | } | |
200 | netdev->tx_work = 0; | |
201 | } | |
202 | g_free(tmpbuf); | |
203 | } | |
204 | ||
205 | /* ------------------------------------------------------------- */ | |
206 | ||
207 | static void net_rx_response(struct XenNetDev *netdev, | |
208 | netif_rx_request_t *req, int8_t st, | |
209 | uint16_t offset, uint16_t size, | |
210 | uint16_t flags) | |
211 | { | |
212 | RING_IDX i = netdev->rx_ring.rsp_prod_pvt; | |
213 | netif_rx_response_t *resp; | |
214 | int notify; | |
215 | ||
216 | resp = RING_GET_RESPONSE(&netdev->rx_ring, i); | |
217 | resp->offset = offset; | |
218 | resp->flags = flags; | |
219 | resp->id = req->id; | |
220 | resp->status = (int16_t)size; | |
221 | if (st < 0) { | |
222 | resp->status = (int16_t)st; | |
223 | } | |
224 | ||
225 | xen_be_printf(&netdev->xendev, 3, "rx response: idx %d, status %d, flags 0x%x\n", | |
226 | i, resp->status, resp->flags); | |
227 | ||
228 | netdev->rx_ring.rsp_prod_pvt = ++i; | |
229 | RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->rx_ring, notify); | |
230 | if (notify) { | |
231 | xen_be_send_notify(&netdev->xendev); | |
232 | } | |
233 | } | |
234 | ||
235 | #define NET_IP_ALIGN 2 | |
236 | ||
237 | static ssize_t net_rx_packet(NetClientState *nc, const uint8_t *buf, size_t size) | |
238 | { | |
239 | struct XenNetDev *netdev = qemu_get_nic_opaque(nc); | |
240 | netif_rx_request_t rxreq; | |
241 | RING_IDX rc, rp; | |
242 | void *page; | |
243 | ||
244 | if (netdev->xendev.be_state != XenbusStateConnected) { | |
245 | return -1; | |
246 | } | |
247 | ||
248 | rc = netdev->rx_ring.req_cons; | |
249 | rp = netdev->rx_ring.sring->req_prod; | |
250 | xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ | |
251 | ||
252 | if (rc == rp || RING_REQUEST_CONS_OVERFLOW(&netdev->rx_ring, rc)) { | |
253 | return 0; | |
254 | } | |
255 | if (size > XC_PAGE_SIZE - NET_IP_ALIGN) { | |
256 | xen_be_printf(&netdev->xendev, 0, "packet too big (%lu > %ld)", | |
257 | (unsigned long)size, XC_PAGE_SIZE - NET_IP_ALIGN); | |
258 | return -1; | |
259 | } | |
260 | ||
261 | memcpy(&rxreq, RING_GET_REQUEST(&netdev->rx_ring, rc), sizeof(rxreq)); | |
262 | netdev->rx_ring.req_cons = ++rc; | |
263 | ||
264 | page = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, | |
265 | netdev->xendev.dom, | |
266 | rxreq.gref, PROT_WRITE); | |
267 | if (page == NULL) { | |
268 | xen_be_printf(&netdev->xendev, 0, "error: rx gref dereference failed (%d)\n", | |
269 | rxreq.gref); | |
270 | net_rx_response(netdev, &rxreq, NETIF_RSP_ERROR, 0, 0, 0); | |
271 | return -1; | |
272 | } | |
273 | memcpy(page + NET_IP_ALIGN, buf, size); | |
274 | xc_gnttab_munmap(netdev->xendev.gnttabdev, page, 1); | |
275 | net_rx_response(netdev, &rxreq, NETIF_RSP_OKAY, NET_IP_ALIGN, size, 0); | |
276 | ||
277 | return size; | |
278 | } | |
279 | ||
280 | /* ------------------------------------------------------------- */ | |
281 | ||
282 | static NetClientInfo net_xen_info = { | |
283 | .type = NET_CLIENT_OPTIONS_KIND_NIC, | |
284 | .size = sizeof(NICState), | |
285 | .receive = net_rx_packet, | |
286 | }; | |
287 | ||
288 | static int net_init(struct XenDevice *xendev) | |
289 | { | |
290 | struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); | |
291 | ||
292 | /* read xenstore entries */ | |
293 | if (netdev->mac == NULL) { | |
294 | netdev->mac = xenstore_read_be_str(&netdev->xendev, "mac"); | |
295 | } | |
296 | ||
297 | /* do we have all we need? */ | |
298 | if (netdev->mac == NULL) { | |
299 | return -1; | |
300 | } | |
301 | ||
302 | if (net_parse_macaddr(netdev->conf.macaddr.a, netdev->mac) < 0) { | |
303 | return -1; | |
304 | } | |
305 | ||
306 | netdev->nic = qemu_new_nic(&net_xen_info, &netdev->conf, | |
307 | "xen", NULL, netdev); | |
308 | ||
309 | snprintf(qemu_get_queue(netdev->nic)->info_str, | |
310 | sizeof(qemu_get_queue(netdev->nic)->info_str), | |
311 | "nic: xenbus vif macaddr=%s", netdev->mac); | |
312 | ||
313 | /* fill info */ | |
314 | xenstore_write_be_int(&netdev->xendev, "feature-rx-copy", 1); | |
315 | xenstore_write_be_int(&netdev->xendev, "feature-rx-flip", 0); | |
316 | ||
317 | return 0; | |
318 | } | |
319 | ||
320 | static int net_connect(struct XenDevice *xendev) | |
321 | { | |
322 | struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); | |
323 | int rx_copy; | |
324 | ||
325 | if (xenstore_read_fe_int(&netdev->xendev, "tx-ring-ref", | |
326 | &netdev->tx_ring_ref) == -1) { | |
327 | return -1; | |
328 | } | |
329 | if (xenstore_read_fe_int(&netdev->xendev, "rx-ring-ref", | |
330 | &netdev->rx_ring_ref) == -1) { | |
331 | return 1; | |
332 | } | |
333 | if (xenstore_read_fe_int(&netdev->xendev, "event-channel", | |
334 | &netdev->xendev.remote_port) == -1) { | |
335 | return -1; | |
336 | } | |
337 | ||
338 | if (xenstore_read_fe_int(&netdev->xendev, "request-rx-copy", &rx_copy) == -1) { | |
339 | rx_copy = 0; | |
340 | } | |
341 | if (rx_copy == 0) { | |
342 | xen_be_printf(&netdev->xendev, 0, "frontend doesn't support rx-copy.\n"); | |
343 | return -1; | |
344 | } | |
345 | ||
346 | netdev->txs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, | |
347 | netdev->xendev.dom, | |
348 | netdev->tx_ring_ref, | |
349 | PROT_READ | PROT_WRITE); | |
350 | if (!netdev->txs) { | |
351 | return -1; | |
352 | } | |
353 | netdev->rxs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, | |
354 | netdev->xendev.dom, | |
355 | netdev->rx_ring_ref, | |
356 | PROT_READ | PROT_WRITE); | |
357 | if (!netdev->rxs) { | |
358 | xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->txs, 1); | |
359 | netdev->txs = NULL; | |
360 | return -1; | |
361 | } | |
362 | BACK_RING_INIT(&netdev->tx_ring, netdev->txs, XC_PAGE_SIZE); | |
363 | BACK_RING_INIT(&netdev->rx_ring, netdev->rxs, XC_PAGE_SIZE); | |
364 | ||
365 | xen_be_bind_evtchn(&netdev->xendev); | |
366 | ||
367 | xen_be_printf(&netdev->xendev, 1, "ok: tx-ring-ref %d, rx-ring-ref %d, " | |
368 | "remote port %d, local port %d\n", | |
369 | netdev->tx_ring_ref, netdev->rx_ring_ref, | |
370 | netdev->xendev.remote_port, netdev->xendev.local_port); | |
371 | ||
372 | net_tx_packets(netdev); | |
373 | return 0; | |
374 | } | |
375 | ||
376 | static void net_disconnect(struct XenDevice *xendev) | |
377 | { | |
378 | struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); | |
379 | ||
380 | xen_be_unbind_evtchn(&netdev->xendev); | |
381 | ||
382 | if (netdev->txs) { | |
383 | xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->txs, 1); | |
384 | netdev->txs = NULL; | |
385 | } | |
386 | if (netdev->rxs) { | |
387 | xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->rxs, 1); | |
388 | netdev->rxs = NULL; | |
389 | } | |
390 | } | |
391 | ||
392 | static void net_event(struct XenDevice *xendev) | |
393 | { | |
394 | struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); | |
395 | net_tx_packets(netdev); | |
396 | qemu_flush_queued_packets(qemu_get_queue(netdev->nic)); | |
397 | } | |
398 | ||
399 | static int net_free(struct XenDevice *xendev) | |
400 | { | |
401 | struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); | |
402 | ||
403 | if (netdev->nic) { | |
404 | qemu_del_nic(netdev->nic); | |
405 | netdev->nic = NULL; | |
406 | } | |
407 | g_free(netdev->mac); | |
408 | netdev->mac = NULL; | |
409 | return 0; | |
410 | } | |
411 | ||
412 | /* ------------------------------------------------------------- */ | |
413 | ||
414 | struct XenDevOps xen_netdev_ops = { | |
415 | .size = sizeof(struct XenNetDev), | |
416 | .flags = DEVOPS_FLAG_NEED_GNTDEV, | |
417 | .init = net_init, | |
418 | .initialise = net_connect, | |
419 | .event = net_event, | |
420 | .disconnect = net_disconnect, | |
421 | .free = net_free, | |
422 | }; |