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.h" 39 #include "net.h" 40 #include "net/checksum.h" 41 #include "net/util.h" 42 #include "qemu-char.h" 43 #include "xen_backend.h" 44 45 #include <xen/io/netif.h> 46 47 /* ------------------------------------------------------------- */ 48 49 struct XenNetDev { 50 struct XenDevice xendev; /* must be first */ 51 char *mac; 52 int tx_work; 53 int tx_ring_ref; 54 int rx_ring_ref; 55 struct netif_tx_sring *txs; 56 struct netif_rx_sring *rxs; 57 netif_tx_back_ring_t tx_ring; 58 netif_rx_back_ring_t rx_ring; 59 NICConf conf; 60 NICState *nic; 61 }; 62 63 /* ------------------------------------------------------------- */ 64 65 static void net_tx_response(struct XenNetDev *netdev, netif_tx_request_t *txp, int8_t st) 66 { 67 RING_IDX i = netdev->tx_ring.rsp_prod_pvt; 68 netif_tx_response_t *resp; 69 int notify; 70 71 resp = RING_GET_RESPONSE(&netdev->tx_ring, i); 72 resp->id = txp->id; 73 resp->status = st; 74 75 #if 0 76 if (txp->flags & NETTXF_extra_info) { 77 RING_GET_RESPONSE(&netdev->tx_ring, ++i)->status = NETIF_RSP_NULL; 78 } 79 #endif 80 81 netdev->tx_ring.rsp_prod_pvt = ++i; 82 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->tx_ring, notify); 83 if (notify) { 84 xen_be_send_notify(&netdev->xendev); 85 } 86 87 if (i == netdev->tx_ring.req_cons) { 88 int more_to_do; 89 RING_FINAL_CHECK_FOR_REQUESTS(&netdev->tx_ring, more_to_do); 90 if (more_to_do) { 91 netdev->tx_work++; 92 } 93 } 94 } 95 96 static void net_tx_error(struct XenNetDev *netdev, netif_tx_request_t *txp, RING_IDX end) 97 { 98 #if 0 99 /* 100 * Hmm, why netback fails everything in the ring? 101 * Should we do that even when not supporting SG and TSO? 102 */ 103 RING_IDX cons = netdev->tx_ring.req_cons; 104 105 do { 106 make_tx_response(netif, txp, NETIF_RSP_ERROR); 107 if (cons >= end) { 108 break; 109 } 110 txp = RING_GET_REQUEST(&netdev->tx_ring, cons++); 111 } while (1); 112 netdev->tx_ring.req_cons = cons; 113 netif_schedule_work(netif); 114 netif_put(netif); 115 #else 116 net_tx_response(netdev, txp, NETIF_RSP_ERROR); 117 #endif 118 } 119 120 static void net_tx_packets(struct XenNetDev *netdev) 121 { 122 netif_tx_request_t txreq; 123 RING_IDX rc, rp; 124 void *page; 125 void *tmpbuf = NULL; 126 127 for (;;) { 128 rc = netdev->tx_ring.req_cons; 129 rp = netdev->tx_ring.sring->req_prod; 130 xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ 131 132 while ((rc != rp)) { 133 if (RING_REQUEST_CONS_OVERFLOW(&netdev->tx_ring, rc)) { 134 break; 135 } 136 memcpy(&txreq, RING_GET_REQUEST(&netdev->tx_ring, rc), sizeof(txreq)); 137 netdev->tx_ring.req_cons = ++rc; 138 139 #if 1 140 /* should not happen in theory, we don't announce the * 141 * feature-{sg,gso,whatelse} flags in xenstore (yet?) */ 142 if (txreq.flags & NETTXF_extra_info) { 143 xen_be_printf(&netdev->xendev, 0, "FIXME: extra info flag\n"); 144 net_tx_error(netdev, &txreq, rc); 145 continue; 146 } 147 if (txreq.flags & NETTXF_more_data) { 148 xen_be_printf(&netdev->xendev, 0, "FIXME: more data flag\n"); 149 net_tx_error(netdev, &txreq, rc); 150 continue; 151 } 152 #endif 153 154 if (txreq.size < 14) { 155 xen_be_printf(&netdev->xendev, 0, "bad packet size: %d\n", txreq.size); 156 net_tx_error(netdev, &txreq, rc); 157 continue; 158 } 159 160 if ((txreq.offset + txreq.size) > XC_PAGE_SIZE) { 161 xen_be_printf(&netdev->xendev, 0, "error: page crossing\n"); 162 net_tx_error(netdev, &txreq, rc); 163 continue; 164 } 165 166 xen_be_printf(&netdev->xendev, 3, "tx packet ref %d, off %d, len %d, flags 0x%x%s%s%s%s\n", 167 txreq.gref, txreq.offset, txreq.size, txreq.flags, 168 (txreq.flags & NETTXF_csum_blank) ? " csum_blank" : "", 169 (txreq.flags & NETTXF_data_validated) ? " data_validated" : "", 170 (txreq.flags & NETTXF_more_data) ? " more_data" : "", 171 (txreq.flags & NETTXF_extra_info) ? " extra_info" : ""); 172 173 page = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, 174 netdev->xendev.dom, 175 txreq.gref, PROT_READ); 176 if (page == NULL) { 177 xen_be_printf(&netdev->xendev, 0, "error: tx gref dereference failed (%d)\n", 178 txreq.gref); 179 net_tx_error(netdev, &txreq, rc); 180 continue; 181 } 182 if (txreq.flags & NETTXF_csum_blank) { 183 /* have read-only mapping -> can't fill checksum in-place */ 184 if (!tmpbuf) { 185 tmpbuf = g_malloc(XC_PAGE_SIZE); 186 } 187 memcpy(tmpbuf, page + txreq.offset, txreq.size); 188 net_checksum_calculate(tmpbuf, txreq.size); 189 qemu_send_packet(&netdev->nic->nc, tmpbuf, txreq.size); 190 } else { 191 qemu_send_packet(&netdev->nic->nc, page + txreq.offset, txreq.size); 192 } 193 xc_gnttab_munmap(netdev->xendev.gnttabdev, page, 1); 194 net_tx_response(netdev, &txreq, NETIF_RSP_OKAY); 195 } 196 if (!netdev->tx_work) { 197 break; 198 } 199 netdev->tx_work = 0; 200 } 201 g_free(tmpbuf); 202 } 203 204 /* ------------------------------------------------------------- */ 205 206 static void net_rx_response(struct XenNetDev *netdev, 207 netif_rx_request_t *req, int8_t st, 208 uint16_t offset, uint16_t size, 209 uint16_t flags) 210 { 211 RING_IDX i = netdev->rx_ring.rsp_prod_pvt; 212 netif_rx_response_t *resp; 213 int notify; 214 215 resp = RING_GET_RESPONSE(&netdev->rx_ring, i); 216 resp->offset = offset; 217 resp->flags = flags; 218 resp->id = req->id; 219 resp->status = (int16_t)size; 220 if (st < 0) { 221 resp->status = (int16_t)st; 222 } 223 224 xen_be_printf(&netdev->xendev, 3, "rx response: idx %d, status %d, flags 0x%x\n", 225 i, resp->status, resp->flags); 226 227 netdev->rx_ring.rsp_prod_pvt = ++i; 228 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->rx_ring, notify); 229 if (notify) { 230 xen_be_send_notify(&netdev->xendev); 231 } 232 } 233 234 #define NET_IP_ALIGN 2 235 236 static int net_rx_ok(NetClientState *nc) 237 { 238 struct XenNetDev *netdev = DO_UPCAST(NICState, nc, nc)->opaque; 239 RING_IDX rc, rp; 240 241 if (netdev->xendev.be_state != XenbusStateConnected) { 242 return 0; 243 } 244 245 rc = netdev->rx_ring.req_cons; 246 rp = netdev->rx_ring.sring->req_prod; 247 xen_rmb(); 248 249 if (rc == rp || RING_REQUEST_CONS_OVERFLOW(&netdev->rx_ring, rc)) { 250 xen_be_printf(&netdev->xendev, 2, "%s: no rx buffers (%d/%d)\n", 251 __FUNCTION__, rc, rp); 252 return 0; 253 } 254 return 1; 255 } 256 257 static ssize_t net_rx_packet(NetClientState *nc, const uint8_t *buf, size_t size) 258 { 259 struct XenNetDev *netdev = DO_UPCAST(NICState, nc, nc)->opaque; 260 netif_rx_request_t rxreq; 261 RING_IDX rc, rp; 262 void *page; 263 264 if (netdev->xendev.be_state != XenbusStateConnected) { 265 return -1; 266 } 267 268 rc = netdev->rx_ring.req_cons; 269 rp = netdev->rx_ring.sring->req_prod; 270 xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ 271 272 if (rc == rp || RING_REQUEST_CONS_OVERFLOW(&netdev->rx_ring, rc)) { 273 xen_be_printf(&netdev->xendev, 2, "no buffer, drop packet\n"); 274 return -1; 275 } 276 if (size > XC_PAGE_SIZE - NET_IP_ALIGN) { 277 xen_be_printf(&netdev->xendev, 0, "packet too big (%lu > %ld)", 278 (unsigned long)size, XC_PAGE_SIZE - NET_IP_ALIGN); 279 return -1; 280 } 281 282 memcpy(&rxreq, RING_GET_REQUEST(&netdev->rx_ring, rc), sizeof(rxreq)); 283 netdev->rx_ring.req_cons = ++rc; 284 285 page = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, 286 netdev->xendev.dom, 287 rxreq.gref, PROT_WRITE); 288 if (page == NULL) { 289 xen_be_printf(&netdev->xendev, 0, "error: rx gref dereference failed (%d)\n", 290 rxreq.gref); 291 net_rx_response(netdev, &rxreq, NETIF_RSP_ERROR, 0, 0, 0); 292 return -1; 293 } 294 memcpy(page + NET_IP_ALIGN, buf, size); 295 xc_gnttab_munmap(netdev->xendev.gnttabdev, page, 1); 296 net_rx_response(netdev, &rxreq, NETIF_RSP_OKAY, NET_IP_ALIGN, size, 0); 297 298 return size; 299 } 300 301 /* ------------------------------------------------------------- */ 302 303 static NetClientInfo net_xen_info = { 304 .type = NET_CLIENT_OPTIONS_KIND_NIC, 305 .size = sizeof(NICState), 306 .can_receive = net_rx_ok, 307 .receive = net_rx_packet, 308 }; 309 310 static int net_init(struct XenDevice *xendev) 311 { 312 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 313 314 /* read xenstore entries */ 315 if (netdev->mac == NULL) { 316 netdev->mac = xenstore_read_be_str(&netdev->xendev, "mac"); 317 } 318 319 /* do we have all we need? */ 320 if (netdev->mac == NULL) { 321 return -1; 322 } 323 324 if (net_parse_macaddr(netdev->conf.macaddr.a, netdev->mac) < 0) { 325 return -1; 326 } 327 328 netdev->conf.peer = NULL; 329 330 netdev->nic = qemu_new_nic(&net_xen_info, &netdev->conf, 331 "xen", NULL, netdev); 332 333 snprintf(netdev->nic->nc.info_str, sizeof(netdev->nic->nc.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 netdev->rxs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, 374 netdev->xendev.dom, 375 netdev->rx_ring_ref, 376 PROT_READ | PROT_WRITE); 377 if (!netdev->txs || !netdev->rxs) { 378 return -1; 379 } 380 BACK_RING_INIT(&netdev->tx_ring, netdev->txs, XC_PAGE_SIZE); 381 BACK_RING_INIT(&netdev->rx_ring, netdev->rxs, XC_PAGE_SIZE); 382 383 xen_be_bind_evtchn(&netdev->xendev); 384 385 xen_be_printf(&netdev->xendev, 1, "ok: tx-ring-ref %d, rx-ring-ref %d, " 386 "remote port %d, local port %d\n", 387 netdev->tx_ring_ref, netdev->rx_ring_ref, 388 netdev->xendev.remote_port, netdev->xendev.local_port); 389 390 net_tx_packets(netdev); 391 return 0; 392 } 393 394 static void net_disconnect(struct XenDevice *xendev) 395 { 396 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 397 398 xen_be_unbind_evtchn(&netdev->xendev); 399 400 if (netdev->txs) { 401 xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->txs, 1); 402 netdev->txs = NULL; 403 } 404 if (netdev->rxs) { 405 xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->rxs, 1); 406 netdev->rxs = NULL; 407 } 408 if (netdev->nic) { 409 qemu_del_net_client(&netdev->nic->nc); 410 netdev->nic = NULL; 411 } 412 } 413 414 static void net_event(struct XenDevice *xendev) 415 { 416 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 417 net_tx_packets(netdev); 418 } 419 420 static int net_free(struct XenDevice *xendev) 421 { 422 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 423 424 g_free(netdev->mac); 425 return 0; 426 } 427 428 /* ------------------------------------------------------------- */ 429 430 struct XenDevOps xen_netdev_ops = { 431 .size = sizeof(struct XenNetDev), 432 .flags = DEVOPS_FLAG_NEED_GNTDEV, 433 .init = net_init, 434 .initialise = net_connect, 435 .event = net_event, 436 .disconnect = net_disconnect, 437 .free = net_free, 438 }; 439