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 "qemu/osdep.h" 23 #include "qemu/main-loop.h" 24 #include "qemu/cutils.h" 25 #include "qemu/log.h" 26 #include "qemu/qemu-print.h" 27 #include "qapi/qmp/qdict.h" 28 #include "qapi/error.h" 29 30 #include <sys/socket.h> 31 #include <sys/ioctl.h> 32 #include <sys/wait.h> 33 34 #include "net/net.h" 35 #include "net/checksum.h" 36 #include "net/util.h" 37 38 #include "hw/xen/xen-backend.h" 39 #include "hw/xen/xen-bus-helper.h" 40 #include "hw/qdev-properties.h" 41 #include "hw/qdev-properties-system.h" 42 43 #include "hw/xen/interface/io/netif.h" 44 #include "hw/xen/interface/io/xs_wire.h" 45 46 #include "trace.h" 47 48 /* ------------------------------------------------------------- */ 49 50 struct XenNetDev { 51 struct XenDevice xendev; /* must be first */ 52 XenEventChannel *event_channel; 53 int dev; 54 int tx_work; 55 unsigned int tx_ring_ref; 56 unsigned int rx_ring_ref; 57 struct netif_tx_sring *txs; 58 struct netif_rx_sring *rxs; 59 netif_tx_back_ring_t tx_ring; 60 netif_rx_back_ring_t rx_ring; 61 NICConf conf; 62 NICState *nic; 63 }; 64 65 typedef struct XenNetDev XenNetDev; 66 67 #define TYPE_XEN_NET_DEVICE "xen-net-device" 68 OBJECT_DECLARE_SIMPLE_TYPE(XenNetDev, XEN_NET_DEVICE) 69 70 /* ------------------------------------------------------------- */ 71 72 static void net_tx_response(struct XenNetDev *netdev, netif_tx_request_t *txp, int8_t st) 73 { 74 RING_IDX i = netdev->tx_ring.rsp_prod_pvt; 75 netif_tx_response_t *resp; 76 int notify; 77 78 resp = RING_GET_RESPONSE(&netdev->tx_ring, i); 79 resp->id = txp->id; 80 resp->status = st; 81 82 #if 0 83 if (txp->flags & NETTXF_extra_info) { 84 RING_GET_RESPONSE(&netdev->tx_ring, ++i)->status = NETIF_RSP_NULL; 85 } 86 #endif 87 88 netdev->tx_ring.rsp_prod_pvt = ++i; 89 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->tx_ring, notify); 90 if (notify) { 91 xen_device_notify_event_channel(XEN_DEVICE(netdev), 92 netdev->event_channel, NULL); 93 } 94 95 if (i == netdev->tx_ring.req_cons) { 96 int more_to_do; 97 RING_FINAL_CHECK_FOR_REQUESTS(&netdev->tx_ring, more_to_do); 98 if (more_to_do) { 99 netdev->tx_work++; 100 } 101 } 102 } 103 104 static void net_tx_error(struct XenNetDev *netdev, netif_tx_request_t *txp, RING_IDX end) 105 { 106 #if 0 107 /* 108 * Hmm, why netback fails everything in the ring? 109 * Should we do that even when not supporting SG and TSO? 110 */ 111 RING_IDX cons = netdev->tx_ring.req_cons; 112 113 do { 114 make_tx_response(netif, txp, NETIF_RSP_ERROR); 115 if (cons >= end) { 116 break; 117 } 118 txp = RING_GET_REQUEST(&netdev->tx_ring, cons++); 119 } while (1); 120 netdev->tx_ring.req_cons = cons; 121 netif_schedule_work(netif); 122 netif_put(netif); 123 #else 124 net_tx_response(netdev, txp, NETIF_RSP_ERROR); 125 #endif 126 } 127 128 static bool net_tx_packets(struct XenNetDev *netdev) 129 { 130 bool done_something = false; 131 netif_tx_request_t txreq; 132 RING_IDX rc, rp; 133 void *page; 134 void *tmpbuf = NULL; 135 136 assert(bql_locked()); 137 138 for (;;) { 139 rc = netdev->tx_ring.req_cons; 140 rp = netdev->tx_ring.sring->req_prod; 141 xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ 142 143 while ((rc != rp)) { 144 if (RING_REQUEST_CONS_OVERFLOW(&netdev->tx_ring, rc)) { 145 break; 146 } 147 memcpy(&txreq, RING_GET_REQUEST(&netdev->tx_ring, rc), sizeof(txreq)); 148 netdev->tx_ring.req_cons = ++rc; 149 done_something = true; 150 151 #if 1 152 /* should not happen in theory, we don't announce the * 153 * feature-{sg,gso,whatelse} flags in xenstore (yet?) */ 154 if (txreq.flags & NETTXF_extra_info) { 155 qemu_log_mask(LOG_UNIMP, "vif%u: FIXME: extra info flag\n", 156 netdev->dev); 157 net_tx_error(netdev, &txreq, rc); 158 continue; 159 } 160 if (txreq.flags & NETTXF_more_data) { 161 qemu_log_mask(LOG_UNIMP, "vif%u: FIXME: more data flag\n", 162 netdev->dev); 163 net_tx_error(netdev, &txreq, rc); 164 continue; 165 } 166 #endif 167 168 if (txreq.size < 14) { 169 qemu_log_mask(LOG_GUEST_ERROR, "vif%u: bad packet size: %d\n", 170 netdev->dev, txreq.size); 171 net_tx_error(netdev, &txreq, rc); 172 continue; 173 } 174 175 if ((txreq.offset + txreq.size) > XEN_PAGE_SIZE) { 176 qemu_log_mask(LOG_GUEST_ERROR, "vif%u: error: page crossing\n", 177 netdev->dev); 178 net_tx_error(netdev, &txreq, rc); 179 continue; 180 } 181 182 trace_xen_netdev_tx(netdev->dev, txreq.gref, txreq.offset, 183 txreq.size, txreq.flags, 184 (txreq.flags & NETTXF_csum_blank) ? " csum_blank" : "", 185 (txreq.flags & NETTXF_data_validated) ? " data_validated" : "", 186 (txreq.flags & NETTXF_more_data) ? " more_data" : "", 187 (txreq.flags & NETTXF_extra_info) ? " extra_info" : ""); 188 189 page = xen_device_map_grant_refs(&netdev->xendev, &txreq.gref, 1, 190 PROT_READ, NULL); 191 if (page == NULL) { 192 qemu_log_mask(LOG_GUEST_ERROR, 193 "vif%u: tx gref dereference failed (%d)\n", 194 netdev->dev, txreq.gref); 195 net_tx_error(netdev, &txreq, rc); 196 continue; 197 } 198 if (txreq.flags & NETTXF_csum_blank) { 199 /* have read-only mapping -> can't fill checksum in-place */ 200 if (!tmpbuf) { 201 tmpbuf = g_malloc(XEN_PAGE_SIZE); 202 } 203 memcpy(tmpbuf, page + txreq.offset, txreq.size); 204 net_checksum_calculate(tmpbuf, txreq.size, CSUM_ALL); 205 qemu_send_packet(qemu_get_queue(netdev->nic), tmpbuf, 206 txreq.size); 207 } else { 208 qemu_send_packet(qemu_get_queue(netdev->nic), 209 page + txreq.offset, txreq.size); 210 } 211 xen_device_unmap_grant_refs(&netdev->xendev, page, &txreq.gref, 1, 212 NULL); 213 net_tx_response(netdev, &txreq, NETIF_RSP_OKAY); 214 } 215 if (!netdev->tx_work) { 216 break; 217 } 218 netdev->tx_work = 0; 219 } 220 g_free(tmpbuf); 221 return done_something; 222 } 223 224 /* ------------------------------------------------------------- */ 225 226 static void net_rx_response(struct XenNetDev *netdev, 227 netif_rx_request_t *req, int8_t st, 228 uint16_t offset, uint16_t size, 229 uint16_t flags) 230 { 231 RING_IDX i = netdev->rx_ring.rsp_prod_pvt; 232 netif_rx_response_t *resp; 233 int notify; 234 235 resp = RING_GET_RESPONSE(&netdev->rx_ring, i); 236 resp->offset = offset; 237 resp->flags = flags; 238 resp->id = req->id; 239 resp->status = (int16_t)size; 240 if (st < 0) { 241 resp->status = (int16_t)st; 242 } 243 244 trace_xen_netdev_rx(netdev->dev, i, resp->status, resp->flags); 245 246 netdev->rx_ring.rsp_prod_pvt = ++i; 247 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->rx_ring, notify); 248 if (notify) { 249 xen_device_notify_event_channel(XEN_DEVICE(netdev), 250 netdev->event_channel, NULL); 251 } 252 } 253 254 #define NET_IP_ALIGN 2 255 256 static ssize_t net_rx_packet(NetClientState *nc, const uint8_t *buf, size_t size) 257 { 258 struct XenNetDev *netdev = qemu_get_nic_opaque(nc); 259 netif_rx_request_t rxreq; 260 RING_IDX rc, rp; 261 void *page; 262 263 assert(bql_locked()); 264 265 if (xen_device_backend_get_state(&netdev->xendev) != 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 return 0; 275 } 276 if (size > XEN_PAGE_SIZE - NET_IP_ALIGN) { 277 qemu_log_mask(LOG_GUEST_ERROR, "vif%u: packet too big (%lu > %ld)", 278 netdev->dev, (unsigned long)size, 279 XEN_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 = xen_device_map_grant_refs(&netdev->xendev, &rxreq.gref, 1, 287 PROT_WRITE, NULL); 288 if (page == NULL) { 289 qemu_log_mask(LOG_GUEST_ERROR, 290 "vif%u: rx gref dereference failed (%d)\n", 291 netdev->dev, 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 xen_device_unmap_grant_refs(&netdev->xendev, page, &rxreq.gref, 1, NULL); 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_DRIVER_NIC, 306 .size = sizeof(NICState), 307 .receive = net_rx_packet, 308 }; 309 310 static void xen_netdev_realize(XenDevice *xendev, Error **errp) 311 { 312 ERRP_GUARD(); 313 XenNetDev *netdev = XEN_NET_DEVICE(xendev); 314 NetClientState *nc; 315 316 qemu_macaddr_default_if_unset(&netdev->conf.macaddr); 317 318 xen_device_frontend_printf(xendev, "mac", "%02x:%02x:%02x:%02x:%02x:%02x", 319 netdev->conf.macaddr.a[0], 320 netdev->conf.macaddr.a[1], 321 netdev->conf.macaddr.a[2], 322 netdev->conf.macaddr.a[3], 323 netdev->conf.macaddr.a[4], 324 netdev->conf.macaddr.a[5]); 325 326 netdev->nic = qemu_new_nic(&net_xen_info, &netdev->conf, 327 object_get_typename(OBJECT(xendev)), 328 DEVICE(xendev)->id, 329 &xendev->qdev.mem_reentrancy_guard, netdev); 330 331 nc = qemu_get_queue(netdev->nic); 332 qemu_format_nic_info_str(nc, netdev->conf.macaddr.a); 333 334 /* fill info */ 335 xen_device_backend_printf(xendev, "feature-rx-copy", "%u", 1); 336 xen_device_backend_printf(xendev, "feature-rx-flip", "%u", 0); 337 338 trace_xen_netdev_realize(netdev->dev, nc->info_str, nc->peer ? 339 nc->peer->name : "(none)"); 340 } 341 342 static bool net_event(void *_xendev) 343 { 344 XenNetDev *netdev = XEN_NET_DEVICE(_xendev); 345 bool done_something; 346 347 done_something = net_tx_packets(netdev); 348 qemu_flush_queued_packets(qemu_get_queue(netdev->nic)); 349 return done_something; 350 } 351 352 static bool xen_netdev_connect(XenDevice *xendev, Error **errp) 353 { 354 ERRP_GUARD(); 355 XenNetDev *netdev = XEN_NET_DEVICE(xendev); 356 unsigned int port, rx_copy; 357 358 assert(bql_locked()); 359 360 if (xen_device_frontend_scanf(xendev, "tx-ring-ref", "%u", 361 &netdev->tx_ring_ref) != 1) { 362 error_setg(errp, "failed to read tx-ring-ref"); 363 return false; 364 } 365 366 if (xen_device_frontend_scanf(xendev, "rx-ring-ref", "%u", 367 &netdev->rx_ring_ref) != 1) { 368 error_setg(errp, "failed to read rx-ring-ref"); 369 return false; 370 } 371 372 if (xen_device_frontend_scanf(xendev, "event-channel", "%u", 373 &port) != 1) { 374 error_setg(errp, "failed to read event-channel"); 375 return false; 376 } 377 378 if (xen_device_frontend_scanf(xendev, "request-rx-copy", "%u", 379 &rx_copy) != 1) { 380 rx_copy = 0; 381 } 382 if (rx_copy == 0) { 383 error_setg(errp, "frontend doesn't support rx-copy"); 384 return false; 385 } 386 387 netdev->txs = xen_device_map_grant_refs(xendev, 388 &netdev->tx_ring_ref, 1, 389 PROT_READ | PROT_WRITE, 390 errp); 391 if (!netdev->txs) { 392 error_prepend(errp, "failed to map tx grant ref: "); 393 return false; 394 } 395 396 netdev->rxs = xen_device_map_grant_refs(xendev, 397 &netdev->rx_ring_ref, 1, 398 PROT_READ | PROT_WRITE, 399 errp); 400 if (!netdev->rxs) { 401 error_prepend(errp, "failed to map rx grant ref: "); 402 return false; 403 } 404 405 BACK_RING_INIT(&netdev->tx_ring, netdev->txs, XEN_PAGE_SIZE); 406 BACK_RING_INIT(&netdev->rx_ring, netdev->rxs, XEN_PAGE_SIZE); 407 408 netdev->event_channel = xen_device_bind_event_channel(xendev, port, 409 net_event, 410 netdev, 411 errp); 412 if (!netdev->event_channel) { 413 return false; 414 } 415 416 trace_xen_netdev_connect(netdev->dev, netdev->tx_ring_ref, 417 netdev->rx_ring_ref, port); 418 419 net_tx_packets(netdev); 420 return true; 421 } 422 423 static void xen_netdev_disconnect(XenDevice *xendev, Error **errp) 424 { 425 XenNetDev *netdev = XEN_NET_DEVICE(xendev); 426 427 trace_xen_netdev_disconnect(netdev->dev); 428 429 assert(bql_locked()); 430 431 netdev->tx_ring.sring = NULL; 432 netdev->rx_ring.sring = NULL; 433 434 if (netdev->event_channel) { 435 xen_device_unbind_event_channel(xendev, netdev->event_channel, 436 errp); 437 netdev->event_channel = NULL; 438 } 439 if (netdev->txs) { 440 xen_device_unmap_grant_refs(xendev, netdev->txs, 441 &netdev->tx_ring_ref, 1, errp); 442 netdev->txs = NULL; 443 } 444 if (netdev->rxs) { 445 xen_device_unmap_grant_refs(xendev, netdev->rxs, 446 &netdev->rx_ring_ref, 1, errp); 447 netdev->rxs = NULL; 448 } 449 } 450 451 /* -------------------------------------------------------------------- */ 452 453 454 static void xen_netdev_frontend_changed(XenDevice *xendev, 455 enum xenbus_state frontend_state, 456 Error **errp) 457 { 458 ERRP_GUARD(); 459 enum xenbus_state backend_state = xen_device_backend_get_state(xendev); 460 461 trace_xen_netdev_frontend_changed(xendev->name, frontend_state); 462 463 switch (frontend_state) { 464 case XenbusStateConnected: 465 if (backend_state == XenbusStateConnected) { 466 break; 467 } 468 469 xen_netdev_disconnect(xendev, errp); 470 if (*errp) { 471 break; 472 } 473 474 if (!xen_netdev_connect(xendev, errp)) { 475 xen_netdev_disconnect(xendev, NULL); 476 xen_device_backend_set_state(xendev, XenbusStateClosing); 477 break; 478 } 479 480 xen_device_backend_set_state(xendev, XenbusStateConnected); 481 break; 482 483 case XenbusStateClosing: 484 xen_device_backend_set_state(xendev, XenbusStateClosing); 485 break; 486 487 case XenbusStateClosed: 488 case XenbusStateUnknown: 489 xen_netdev_disconnect(xendev, errp); 490 if (*errp) { 491 break; 492 } 493 494 xen_device_backend_set_state(xendev, XenbusStateClosed); 495 break; 496 497 case XenbusStateInitialised: 498 /* 499 * Linux netback does nothing on the frontend going (back) to 500 * XenbusStateInitialised, so do the same here. 501 */ 502 default: 503 break; 504 } 505 } 506 507 static char *xen_netdev_get_name(XenDevice *xendev, Error **errp) 508 { 509 XenNetDev *netdev = XEN_NET_DEVICE(xendev); 510 511 if (netdev->dev == -1) { 512 XenBus *xenbus = XEN_BUS(qdev_get_parent_bus(DEVICE(xendev))); 513 char fe_path[XENSTORE_ABS_PATH_MAX + 1]; 514 int idx = (xen_mode == XEN_EMULATE) ? 0 : 1; 515 char *value; 516 517 /* Theoretically we could go up to INT_MAX here but that's overkill */ 518 while (idx < 100) { 519 snprintf(fe_path, sizeof(fe_path), 520 "/local/domain/%u/device/vif/%u", 521 xendev->frontend_id, idx); 522 value = qemu_xen_xs_read(xenbus->xsh, XBT_NULL, fe_path, NULL); 523 if (!value) { 524 if (errno == ENOENT) { 525 netdev->dev = idx; 526 goto found; 527 } 528 error_setg(errp, "cannot read %s: %s", fe_path, 529 strerror(errno)); 530 return NULL; 531 } 532 free(value); 533 idx++; 534 } 535 error_setg(errp, "cannot find device index for netdev device"); 536 return NULL; 537 } 538 found: 539 return g_strdup_printf("%u", netdev->dev); 540 } 541 542 static void xen_netdev_unrealize(XenDevice *xendev) 543 { 544 XenNetDev *netdev = XEN_NET_DEVICE(xendev); 545 546 trace_xen_netdev_unrealize(netdev->dev); 547 548 /* Disconnect from the frontend in case this has not already happened */ 549 xen_netdev_disconnect(xendev, NULL); 550 551 if (netdev->nic) { 552 qemu_del_nic(netdev->nic); 553 } 554 } 555 556 /* ------------------------------------------------------------- */ 557 558 static Property xen_netdev_properties[] = { 559 DEFINE_NIC_PROPERTIES(XenNetDev, conf), 560 DEFINE_PROP_INT32("idx", XenNetDev, dev, -1), 561 DEFINE_PROP_END_OF_LIST(), 562 }; 563 564 static void xen_netdev_class_init(ObjectClass *class, void *data) 565 { 566 DeviceClass *dev_class = DEVICE_CLASS(class); 567 XenDeviceClass *xendev_class = XEN_DEVICE_CLASS(class); 568 569 xendev_class->backend = "qnic"; 570 xendev_class->device = "vif"; 571 xendev_class->get_name = xen_netdev_get_name; 572 xendev_class->realize = xen_netdev_realize; 573 xendev_class->frontend_changed = xen_netdev_frontend_changed; 574 xendev_class->unrealize = xen_netdev_unrealize; 575 set_bit(DEVICE_CATEGORY_NETWORK, dev_class->categories); 576 dev_class->user_creatable = true; 577 578 device_class_set_props(dev_class, xen_netdev_properties); 579 } 580 581 static const TypeInfo xen_net_type_info = { 582 .name = TYPE_XEN_NET_DEVICE, 583 .parent = TYPE_XEN_DEVICE, 584 .instance_size = sizeof(XenNetDev), 585 .class_init = xen_netdev_class_init, 586 }; 587 588 static void xen_net_register_types(void) 589 { 590 type_register_static(&xen_net_type_info); 591 } 592 593 type_init(xen_net_register_types) 594 595 /* Called to instantiate a XenNetDev when the backend is detected. */ 596 static void xen_net_device_create(XenBackendInstance *backend, 597 QDict *opts, Error **errp) 598 { 599 ERRP_GUARD(); 600 XenBus *xenbus = xen_backend_get_bus(backend); 601 const char *name = xen_backend_get_name(backend); 602 XenDevice *xendev = NULL; 603 unsigned long number; 604 const char *macstr; 605 XenNetDev *net; 606 MACAddr mac; 607 608 if (qemu_strtoul(name, NULL, 10, &number) || number >= INT_MAX) { 609 error_setg(errp, "failed to parse name '%s'", name); 610 goto fail; 611 } 612 613 trace_xen_netdev_create(number); 614 615 macstr = qdict_get_try_str(opts, "mac"); 616 if (macstr == NULL) { 617 error_setg(errp, "no MAC address found"); 618 goto fail; 619 } 620 621 if (net_parse_macaddr(mac.a, macstr) < 0) { 622 error_setg(errp, "failed to parse MAC address"); 623 goto fail; 624 } 625 626 xendev = XEN_DEVICE(qdev_new(TYPE_XEN_NET_DEVICE)); 627 net = XEN_NET_DEVICE(xendev); 628 629 net->dev = number; 630 memcpy(&net->conf.macaddr, &mac, sizeof(mac)); 631 632 if (qdev_realize_and_unref(DEVICE(xendev), BUS(xenbus), errp)) { 633 xen_backend_set_device(backend, xendev); 634 return; 635 } 636 637 error_prepend(errp, "realization of net device %lu failed: ", 638 number); 639 640 fail: 641 if (xendev) { 642 object_unparent(OBJECT(xendev)); 643 } 644 } 645 646 static void xen_net_device_destroy(XenBackendInstance *backend, 647 Error **errp) 648 { 649 ERRP_GUARD(); 650 XenDevice *xendev = xen_backend_get_device(backend); 651 XenNetDev *netdev = XEN_NET_DEVICE(xendev); 652 653 trace_xen_netdev_destroy(netdev->dev); 654 655 object_unparent(OBJECT(xendev)); 656 } 657 658 static const XenBackendInfo xen_net_backend_info = { 659 .type = "qnic", 660 .create = xen_net_device_create, 661 .destroy = xen_net_device_destroy, 662 }; 663 664 static void xen_net_register_backend(void) 665 { 666 xen_backend_register(&xen_net_backend_info); 667 } 668 669 xen_backend_init(xen_net_register_backend); 670