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 int net_rx_ok(NetClientState *nc) 238 { 239 struct XenNetDev *netdev = qemu_get_nic_opaque(nc); 240 RING_IDX rc, rp; 241 242 if (netdev->xendev.be_state != XenbusStateConnected) { 243 return 0; 244 } 245 246 rc = netdev->rx_ring.req_cons; 247 rp = netdev->rx_ring.sring->req_prod; 248 xen_rmb(); 249 250 if (rc == rp || RING_REQUEST_CONS_OVERFLOW(&netdev->rx_ring, rc)) { 251 xen_be_printf(&netdev->xendev, 2, "%s: no rx buffers (%d/%d)\n", 252 __FUNCTION__, rc, rp); 253 return 0; 254 } 255 return 1; 256 } 257 258 static ssize_t net_rx_packet(NetClientState *nc, const uint8_t *buf, size_t size) 259 { 260 struct XenNetDev *netdev = qemu_get_nic_opaque(nc); 261 netif_rx_request_t rxreq; 262 RING_IDX rc, rp; 263 void *page; 264 265 if (netdev->xendev.be_state != XenbusStateConnected) { 266 return -1; 267 } 268 269 rc = netdev->rx_ring.req_cons; 270 rp = netdev->rx_ring.sring->req_prod; 271 xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ 272 273 if (rc == rp || RING_REQUEST_CONS_OVERFLOW(&netdev->rx_ring, rc)) { 274 xen_be_printf(&netdev->xendev, 2, "no buffer, drop packet\n"); 275 return -1; 276 } 277 if (size > XC_PAGE_SIZE - NET_IP_ALIGN) { 278 xen_be_printf(&netdev->xendev, 0, "packet too big (%lu > %ld)", 279 (unsigned long)size, XC_PAGE_SIZE - NET_IP_ALIGN); 280 return -1; 281 } 282 283 memcpy(&rxreq, RING_GET_REQUEST(&netdev->rx_ring, rc), sizeof(rxreq)); 284 netdev->rx_ring.req_cons = ++rc; 285 286 page = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, 287 netdev->xendev.dom, 288 rxreq.gref, PROT_WRITE); 289 if (page == NULL) { 290 xen_be_printf(&netdev->xendev, 0, "error: rx gref dereference failed (%d)\n", 291 rxreq.gref); 292 net_rx_response(netdev, &rxreq, NETIF_RSP_ERROR, 0, 0, 0); 293 return -1; 294 } 295 memcpy(page + NET_IP_ALIGN, buf, size); 296 xc_gnttab_munmap(netdev->xendev.gnttabdev, page, 1); 297 net_rx_response(netdev, &rxreq, NETIF_RSP_OKAY, NET_IP_ALIGN, size, 0); 298 299 return size; 300 } 301 302 /* ------------------------------------------------------------- */ 303 304 static NetClientInfo net_xen_info = { 305 .type = NET_CLIENT_OPTIONS_KIND_NIC, 306 .size = sizeof(NICState), 307 .can_receive = net_rx_ok, 308 .receive = net_rx_packet, 309 }; 310 311 static int net_init(struct XenDevice *xendev) 312 { 313 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 314 315 /* read xenstore entries */ 316 if (netdev->mac == NULL) { 317 netdev->mac = xenstore_read_be_str(&netdev->xendev, "mac"); 318 } 319 320 /* do we have all we need? */ 321 if (netdev->mac == NULL) { 322 return -1; 323 } 324 325 if (net_parse_macaddr(netdev->conf.macaddr.a, netdev->mac) < 0) { 326 return -1; 327 } 328 329 netdev->nic = qemu_new_nic(&net_xen_info, &netdev->conf, 330 "xen", NULL, netdev); 331 332 snprintf(qemu_get_queue(netdev->nic)->info_str, 333 sizeof(qemu_get_queue(netdev->nic)->info_str), 334 "nic: xenbus vif macaddr=%s", netdev->mac); 335 336 /* fill info */ 337 xenstore_write_be_int(&netdev->xendev, "feature-rx-copy", 1); 338 xenstore_write_be_int(&netdev->xendev, "feature-rx-flip", 0); 339 340 return 0; 341 } 342 343 static int net_connect(struct XenDevice *xendev) 344 { 345 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 346 int rx_copy; 347 348 if (xenstore_read_fe_int(&netdev->xendev, "tx-ring-ref", 349 &netdev->tx_ring_ref) == -1) { 350 return -1; 351 } 352 if (xenstore_read_fe_int(&netdev->xendev, "rx-ring-ref", 353 &netdev->rx_ring_ref) == -1) { 354 return 1; 355 } 356 if (xenstore_read_fe_int(&netdev->xendev, "event-channel", 357 &netdev->xendev.remote_port) == -1) { 358 return -1; 359 } 360 361 if (xenstore_read_fe_int(&netdev->xendev, "request-rx-copy", &rx_copy) == -1) { 362 rx_copy = 0; 363 } 364 if (rx_copy == 0) { 365 xen_be_printf(&netdev->xendev, 0, "frontend doesn't support rx-copy.\n"); 366 return -1; 367 } 368 369 netdev->txs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, 370 netdev->xendev.dom, 371 netdev->tx_ring_ref, 372 PROT_READ | PROT_WRITE); 373 if (!netdev->txs) { 374 return -1; 375 } 376 netdev->rxs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, 377 netdev->xendev.dom, 378 netdev->rx_ring_ref, 379 PROT_READ | PROT_WRITE); 380 if (!netdev->rxs) { 381 xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->txs, 1); 382 netdev->txs = NULL; 383 return -1; 384 } 385 BACK_RING_INIT(&netdev->tx_ring, netdev->txs, XC_PAGE_SIZE); 386 BACK_RING_INIT(&netdev->rx_ring, netdev->rxs, XC_PAGE_SIZE); 387 388 xen_be_bind_evtchn(&netdev->xendev); 389 390 xen_be_printf(&netdev->xendev, 1, "ok: tx-ring-ref %d, rx-ring-ref %d, " 391 "remote port %d, local port %d\n", 392 netdev->tx_ring_ref, netdev->rx_ring_ref, 393 netdev->xendev.remote_port, netdev->xendev.local_port); 394 395 net_tx_packets(netdev); 396 return 0; 397 } 398 399 static void net_disconnect(struct XenDevice *xendev) 400 { 401 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 402 403 xen_be_unbind_evtchn(&netdev->xendev); 404 405 if (netdev->txs) { 406 xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->txs, 1); 407 netdev->txs = NULL; 408 } 409 if (netdev->rxs) { 410 xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->rxs, 1); 411 netdev->rxs = NULL; 412 } 413 } 414 415 static void net_event(struct XenDevice *xendev) 416 { 417 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 418 net_tx_packets(netdev); 419 qemu_flush_queued_packets(qemu_get_queue(netdev->nic)); 420 } 421 422 static int net_free(struct XenDevice *xendev) 423 { 424 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 425 426 if (netdev->nic) { 427 qemu_del_nic(netdev->nic); 428 netdev->nic = NULL; 429 } 430 g_free(netdev->mac); 431 netdev->mac = NULL; 432 return 0; 433 } 434 435 /* ------------------------------------------------------------- */ 436 437 struct XenDevOps xen_netdev_ops = { 438 .size = sizeof(struct XenNetDev), 439 .flags = DEVOPS_FLAG_NEED_GNTDEV, 440 .init = net_init, 441 .initialise = net_connect, 442 .event = net_event, 443 .disconnect = net_disconnect, 444 .free = net_free, 445 }; 446