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 19 #include <stdio.h> 20 #include <stdlib.h> 21 #include <stdarg.h> 22 #include <string.h> 23 #include <unistd.h> 24 #include <signal.h> 25 #include <inttypes.h> 26 #include <fcntl.h> 27 #include <errno.h> 28 #include <pthread.h> 29 #include <sys/socket.h> 30 #include <sys/ioctl.h> 31 #include <sys/types.h> 32 #include <sys/stat.h> 33 #include <sys/mman.h> 34 #include <sys/wait.h> 35 36 #include <xs.h> 37 #include <xenctrl.h> 38 #include <xen/io/xenbus.h> 39 #include <xen/io/netif.h> 40 41 #include "hw.h" 42 #include "net.h" 43 #include "net/checksum.h" 44 #include "net/util.h" 45 #include "qemu-char.h" 46 #include "xen_backend.h" 47 48 /* ------------------------------------------------------------- */ 49 50 struct XenNetDev { 51 struct XenDevice xendev; /* must be first */ 52 char *mac; 53 int tx_work; 54 int tx_ring_ref; 55 int rx_ring_ref; 56 struct netif_tx_sring *txs; 57 struct netif_rx_sring *rxs; 58 netif_tx_back_ring_t tx_ring; 59 netif_rx_back_ring_t rx_ring; 60 NICConf conf; 61 NICState *nic; 62 }; 63 64 /* ------------------------------------------------------------- */ 65 66 static void net_tx_response(struct XenNetDev *netdev, netif_tx_request_t *txp, int8_t st) 67 { 68 RING_IDX i = netdev->tx_ring.rsp_prod_pvt; 69 netif_tx_response_t *resp; 70 int notify; 71 72 resp = RING_GET_RESPONSE(&netdev->tx_ring, i); 73 resp->id = txp->id; 74 resp->status = st; 75 76 #if 0 77 if (txp->flags & NETTXF_extra_info) { 78 RING_GET_RESPONSE(&netdev->tx_ring, ++i)->status = NETIF_RSP_NULL; 79 } 80 #endif 81 82 netdev->tx_ring.rsp_prod_pvt = ++i; 83 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->tx_ring, notify); 84 if (notify) { 85 xen_be_send_notify(&netdev->xendev); 86 } 87 88 if (i == netdev->tx_ring.req_cons) { 89 int more_to_do; 90 RING_FINAL_CHECK_FOR_REQUESTS(&netdev->tx_ring, more_to_do); 91 if (more_to_do) { 92 netdev->tx_work++; 93 } 94 } 95 } 96 97 static void net_tx_error(struct XenNetDev *netdev, netif_tx_request_t *txp, RING_IDX end) 98 { 99 #if 0 100 /* 101 * Hmm, why netback fails everything in the ring? 102 * Should we do that even when not supporting SG and TSO? 103 */ 104 RING_IDX cons = netdev->tx_ring.req_cons; 105 106 do { 107 make_tx_response(netif, txp, NETIF_RSP_ERROR); 108 if (cons >= end) { 109 break; 110 } 111 txp = RING_GET_REQUEST(&netdev->tx_ring, cons++); 112 } while (1); 113 netdev->tx_ring.req_cons = cons; 114 netif_schedule_work(netif); 115 netif_put(netif); 116 #else 117 net_tx_response(netdev, txp, NETIF_RSP_ERROR); 118 #endif 119 } 120 121 static void net_tx_packets(struct XenNetDev *netdev) 122 { 123 netif_tx_request_t txreq; 124 RING_IDX rc, rp; 125 void *page; 126 void *tmpbuf = NULL; 127 128 for (;;) { 129 rc = netdev->tx_ring.req_cons; 130 rp = netdev->tx_ring.sring->req_prod; 131 xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ 132 133 while ((rc != rp)) { 134 if (RING_REQUEST_CONS_OVERFLOW(&netdev->tx_ring, rc)) { 135 break; 136 } 137 memcpy(&txreq, RING_GET_REQUEST(&netdev->tx_ring, rc), sizeof(txreq)); 138 netdev->tx_ring.req_cons = ++rc; 139 140 #if 1 141 /* should not happen in theory, we don't announce the * 142 * feature-{sg,gso,whatelse} flags in xenstore (yet?) */ 143 if (txreq.flags & NETTXF_extra_info) { 144 xen_be_printf(&netdev->xendev, 0, "FIXME: extra info flag\n"); 145 net_tx_error(netdev, &txreq, rc); 146 continue; 147 } 148 if (txreq.flags & NETTXF_more_data) { 149 xen_be_printf(&netdev->xendev, 0, "FIXME: more data flag\n"); 150 net_tx_error(netdev, &txreq, rc); 151 continue; 152 } 153 #endif 154 155 if (txreq.size < 14) { 156 xen_be_printf(&netdev->xendev, 0, "bad packet size: %d\n", txreq.size); 157 net_tx_error(netdev, &txreq, rc); 158 continue; 159 } 160 161 if ((txreq.offset + txreq.size) > XC_PAGE_SIZE) { 162 xen_be_printf(&netdev->xendev, 0, "error: page crossing\n"); 163 net_tx_error(netdev, &txreq, rc); 164 continue; 165 } 166 167 xen_be_printf(&netdev->xendev, 3, "tx packet ref %d, off %d, len %d, flags 0x%x%s%s%s%s\n", 168 txreq.gref, txreq.offset, txreq.size, txreq.flags, 169 (txreq.flags & NETTXF_csum_blank) ? " csum_blank" : "", 170 (txreq.flags & NETTXF_data_validated) ? " data_validated" : "", 171 (txreq.flags & NETTXF_more_data) ? " more_data" : "", 172 (txreq.flags & NETTXF_extra_info) ? " extra_info" : ""); 173 174 page = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, 175 netdev->xendev.dom, 176 txreq.gref, PROT_READ); 177 if (page == NULL) { 178 xen_be_printf(&netdev->xendev, 0, "error: tx gref dereference failed (%d)\n", 179 txreq.gref); 180 net_tx_error(netdev, &txreq, rc); 181 continue; 182 } 183 if (txreq.flags & NETTXF_csum_blank) { 184 /* have read-only mapping -> can't fill checksum in-place */ 185 if (!tmpbuf) { 186 tmpbuf = g_malloc(XC_PAGE_SIZE); 187 } 188 memcpy(tmpbuf, page + txreq.offset, txreq.size); 189 net_checksum_calculate(tmpbuf, txreq.size); 190 qemu_send_packet(&netdev->nic->nc, tmpbuf, txreq.size); 191 } else { 192 qemu_send_packet(&netdev->nic->nc, 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(VLANClientState *nc) 238 { 239 struct XenNetDev *netdev = DO_UPCAST(NICState, nc, nc)->opaque; 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(VLANClientState *nc, const uint8_t *buf, size_t size) 259 { 260 struct XenNetDev *netdev = DO_UPCAST(NICState, nc, nc)->opaque; 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_TYPE_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->conf.vlan = qemu_find_vlan(netdev->xendev.dev, 1); 330 netdev->conf.peer = NULL; 331 332 netdev->nic = qemu_new_nic(&net_xen_info, &netdev->conf, 333 "xen", NULL, netdev); 334 335 snprintf(netdev->nic->nc.info_str, sizeof(netdev->nic->nc.info_str), 336 "nic: xenbus vif macaddr=%s", netdev->mac); 337 338 /* fill info */ 339 xenstore_write_be_int(&netdev->xendev, "feature-rx-copy", 1); 340 xenstore_write_be_int(&netdev->xendev, "feature-rx-flip", 0); 341 342 return 0; 343 } 344 345 static int net_connect(struct XenDevice *xendev) 346 { 347 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 348 int rx_copy; 349 350 if (xenstore_read_fe_int(&netdev->xendev, "tx-ring-ref", 351 &netdev->tx_ring_ref) == -1) { 352 return -1; 353 } 354 if (xenstore_read_fe_int(&netdev->xendev, "rx-ring-ref", 355 &netdev->rx_ring_ref) == -1) { 356 return 1; 357 } 358 if (xenstore_read_fe_int(&netdev->xendev, "event-channel", 359 &netdev->xendev.remote_port) == -1) { 360 return -1; 361 } 362 363 if (xenstore_read_fe_int(&netdev->xendev, "request-rx-copy", &rx_copy) == -1) { 364 rx_copy = 0; 365 } 366 if (rx_copy == 0) { 367 xen_be_printf(&netdev->xendev, 0, "frontend doesn't support rx-copy.\n"); 368 return -1; 369 } 370 371 netdev->txs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, 372 netdev->xendev.dom, 373 netdev->tx_ring_ref, 374 PROT_READ | PROT_WRITE); 375 netdev->rxs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, 376 netdev->xendev.dom, 377 netdev->rx_ring_ref, 378 PROT_READ | PROT_WRITE); 379 if (!netdev->txs || !netdev->rxs) { 380 return -1; 381 } 382 BACK_RING_INIT(&netdev->tx_ring, netdev->txs, XC_PAGE_SIZE); 383 BACK_RING_INIT(&netdev->rx_ring, netdev->rxs, XC_PAGE_SIZE); 384 385 xen_be_bind_evtchn(&netdev->xendev); 386 387 xen_be_printf(&netdev->xendev, 1, "ok: tx-ring-ref %d, rx-ring-ref %d, " 388 "remote port %d, local port %d\n", 389 netdev->tx_ring_ref, netdev->rx_ring_ref, 390 netdev->xendev.remote_port, netdev->xendev.local_port); 391 392 net_tx_packets(netdev); 393 return 0; 394 } 395 396 static void net_disconnect(struct XenDevice *xendev) 397 { 398 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 399 400 xen_be_unbind_evtchn(&netdev->xendev); 401 402 if (netdev->txs) { 403 xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->txs, 1); 404 netdev->txs = NULL; 405 } 406 if (netdev->rxs) { 407 xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->rxs, 1); 408 netdev->rxs = NULL; 409 } 410 if (netdev->nic) { 411 qemu_del_vlan_client(&netdev->nic->nc); 412 netdev->nic = NULL; 413 } 414 } 415 416 static void net_event(struct XenDevice *xendev) 417 { 418 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 419 net_tx_packets(netdev); 420 } 421 422 static int net_free(struct XenDevice *xendev) 423 { 424 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 425 426 g_free(netdev->mac); 427 return 0; 428 } 429 430 /* ------------------------------------------------------------- */ 431 432 struct XenDevOps xen_netdev_ops = { 433 .size = sizeof(struct XenNetDev), 434 .flags = DEVOPS_FLAG_NEED_GNTDEV, 435 .init = net_init, 436 .connect = net_connect, 437 .event = net_event, 438 .disconnect = net_disconnect, 439 .free = net_free, 440 }; 441