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