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 <sys/socket.h> 24 #include <sys/ioctl.h> 25 #include <sys/mman.h> 26 #include <sys/wait.h> 27 28 #include "hw/hw.h" 29 #include "net/net.h" 30 #include "net/checksum.h" 31 #include "net/util.h" 32 #include "hw/xen/xen_backend.h" 33 34 #include <xen/io/netif.h> 35 36 /* ------------------------------------------------------------- */ 37 38 struct XenNetDev { 39 struct XenDevice xendev; /* must be first */ 40 char *mac; 41 int tx_work; 42 int tx_ring_ref; 43 int rx_ring_ref; 44 struct netif_tx_sring *txs; 45 struct netif_rx_sring *rxs; 46 netif_tx_back_ring_t tx_ring; 47 netif_rx_back_ring_t rx_ring; 48 NICConf conf; 49 NICState *nic; 50 }; 51 52 /* ------------------------------------------------------------- */ 53 54 static void net_tx_response(struct XenNetDev *netdev, netif_tx_request_t *txp, int8_t st) 55 { 56 RING_IDX i = netdev->tx_ring.rsp_prod_pvt; 57 netif_tx_response_t *resp; 58 int notify; 59 60 resp = RING_GET_RESPONSE(&netdev->tx_ring, i); 61 resp->id = txp->id; 62 resp->status = st; 63 64 #if 0 65 if (txp->flags & NETTXF_extra_info) { 66 RING_GET_RESPONSE(&netdev->tx_ring, ++i)->status = NETIF_RSP_NULL; 67 } 68 #endif 69 70 netdev->tx_ring.rsp_prod_pvt = ++i; 71 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->tx_ring, notify); 72 if (notify) { 73 xen_be_send_notify(&netdev->xendev); 74 } 75 76 if (i == netdev->tx_ring.req_cons) { 77 int more_to_do; 78 RING_FINAL_CHECK_FOR_REQUESTS(&netdev->tx_ring, more_to_do); 79 if (more_to_do) { 80 netdev->tx_work++; 81 } 82 } 83 } 84 85 static void net_tx_error(struct XenNetDev *netdev, netif_tx_request_t *txp, RING_IDX end) 86 { 87 #if 0 88 /* 89 * Hmm, why netback fails everything in the ring? 90 * Should we do that even when not supporting SG and TSO? 91 */ 92 RING_IDX cons = netdev->tx_ring.req_cons; 93 94 do { 95 make_tx_response(netif, txp, NETIF_RSP_ERROR); 96 if (cons >= end) { 97 break; 98 } 99 txp = RING_GET_REQUEST(&netdev->tx_ring, cons++); 100 } while (1); 101 netdev->tx_ring.req_cons = cons; 102 netif_schedule_work(netif); 103 netif_put(netif); 104 #else 105 net_tx_response(netdev, txp, NETIF_RSP_ERROR); 106 #endif 107 } 108 109 static void net_tx_packets(struct XenNetDev *netdev) 110 { 111 netif_tx_request_t txreq; 112 RING_IDX rc, rp; 113 void *page; 114 void *tmpbuf = NULL; 115 116 for (;;) { 117 rc = netdev->tx_ring.req_cons; 118 rp = netdev->tx_ring.sring->req_prod; 119 xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ 120 121 while ((rc != rp)) { 122 if (RING_REQUEST_CONS_OVERFLOW(&netdev->tx_ring, rc)) { 123 break; 124 } 125 memcpy(&txreq, RING_GET_REQUEST(&netdev->tx_ring, rc), sizeof(txreq)); 126 netdev->tx_ring.req_cons = ++rc; 127 128 #if 1 129 /* should not happen in theory, we don't announce the * 130 * feature-{sg,gso,whatelse} flags in xenstore (yet?) */ 131 if (txreq.flags & NETTXF_extra_info) { 132 xen_be_printf(&netdev->xendev, 0, "FIXME: extra info flag\n"); 133 net_tx_error(netdev, &txreq, rc); 134 continue; 135 } 136 if (txreq.flags & NETTXF_more_data) { 137 xen_be_printf(&netdev->xendev, 0, "FIXME: more data flag\n"); 138 net_tx_error(netdev, &txreq, rc); 139 continue; 140 } 141 #endif 142 143 if (txreq.size < 14) { 144 xen_be_printf(&netdev->xendev, 0, "bad packet size: %d\n", txreq.size); 145 net_tx_error(netdev, &txreq, rc); 146 continue; 147 } 148 149 if ((txreq.offset + txreq.size) > XC_PAGE_SIZE) { 150 xen_be_printf(&netdev->xendev, 0, "error: page crossing\n"); 151 net_tx_error(netdev, &txreq, rc); 152 continue; 153 } 154 155 xen_be_printf(&netdev->xendev, 3, "tx packet ref %d, off %d, len %d, flags 0x%x%s%s%s%s\n", 156 txreq.gref, txreq.offset, txreq.size, txreq.flags, 157 (txreq.flags & NETTXF_csum_blank) ? " csum_blank" : "", 158 (txreq.flags & NETTXF_data_validated) ? " data_validated" : "", 159 (txreq.flags & NETTXF_more_data) ? " more_data" : "", 160 (txreq.flags & NETTXF_extra_info) ? " extra_info" : ""); 161 162 page = xengnttab_map_grant_ref(netdev->xendev.gnttabdev, 163 netdev->xendev.dom, 164 txreq.gref, PROT_READ); 165 if (page == NULL) { 166 xen_be_printf(&netdev->xendev, 0, "error: tx gref dereference failed (%d)\n", 167 txreq.gref); 168 net_tx_error(netdev, &txreq, rc); 169 continue; 170 } 171 if (txreq.flags & NETTXF_csum_blank) { 172 /* have read-only mapping -> can't fill checksum in-place */ 173 if (!tmpbuf) { 174 tmpbuf = g_malloc(XC_PAGE_SIZE); 175 } 176 memcpy(tmpbuf, page + txreq.offset, txreq.size); 177 net_checksum_calculate(tmpbuf, txreq.size); 178 qemu_send_packet(qemu_get_queue(netdev->nic), tmpbuf, 179 txreq.size); 180 } else { 181 qemu_send_packet(qemu_get_queue(netdev->nic), 182 page + txreq.offset, txreq.size); 183 } 184 xengnttab_unmap(netdev->xendev.gnttabdev, page, 1); 185 net_tx_response(netdev, &txreq, NETIF_RSP_OKAY); 186 } 187 if (!netdev->tx_work) { 188 break; 189 } 190 netdev->tx_work = 0; 191 } 192 g_free(tmpbuf); 193 } 194 195 /* ------------------------------------------------------------- */ 196 197 static void net_rx_response(struct XenNetDev *netdev, 198 netif_rx_request_t *req, int8_t st, 199 uint16_t offset, uint16_t size, 200 uint16_t flags) 201 { 202 RING_IDX i = netdev->rx_ring.rsp_prod_pvt; 203 netif_rx_response_t *resp; 204 int notify; 205 206 resp = RING_GET_RESPONSE(&netdev->rx_ring, i); 207 resp->offset = offset; 208 resp->flags = flags; 209 resp->id = req->id; 210 resp->status = (int16_t)size; 211 if (st < 0) { 212 resp->status = (int16_t)st; 213 } 214 215 xen_be_printf(&netdev->xendev, 3, "rx response: idx %d, status %d, flags 0x%x\n", 216 i, resp->status, resp->flags); 217 218 netdev->rx_ring.rsp_prod_pvt = ++i; 219 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->rx_ring, notify); 220 if (notify) { 221 xen_be_send_notify(&netdev->xendev); 222 } 223 } 224 225 #define NET_IP_ALIGN 2 226 227 static ssize_t net_rx_packet(NetClientState *nc, const uint8_t *buf, size_t size) 228 { 229 struct XenNetDev *netdev = qemu_get_nic_opaque(nc); 230 netif_rx_request_t rxreq; 231 RING_IDX rc, rp; 232 void *page; 233 234 if (netdev->xendev.be_state != XenbusStateConnected) { 235 return -1; 236 } 237 238 rc = netdev->rx_ring.req_cons; 239 rp = netdev->rx_ring.sring->req_prod; 240 xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ 241 242 if (rc == rp || RING_REQUEST_CONS_OVERFLOW(&netdev->rx_ring, rc)) { 243 return 0; 244 } 245 if (size > XC_PAGE_SIZE - NET_IP_ALIGN) { 246 xen_be_printf(&netdev->xendev, 0, "packet too big (%lu > %ld)", 247 (unsigned long)size, XC_PAGE_SIZE - NET_IP_ALIGN); 248 return -1; 249 } 250 251 memcpy(&rxreq, RING_GET_REQUEST(&netdev->rx_ring, rc), sizeof(rxreq)); 252 netdev->rx_ring.req_cons = ++rc; 253 254 page = xengnttab_map_grant_ref(netdev->xendev.gnttabdev, 255 netdev->xendev.dom, 256 rxreq.gref, PROT_WRITE); 257 if (page == NULL) { 258 xen_be_printf(&netdev->xendev, 0, "error: rx gref dereference failed (%d)\n", 259 rxreq.gref); 260 net_rx_response(netdev, &rxreq, NETIF_RSP_ERROR, 0, 0, 0); 261 return -1; 262 } 263 memcpy(page + NET_IP_ALIGN, buf, size); 264 xengnttab_unmap(netdev->xendev.gnttabdev, page, 1); 265 net_rx_response(netdev, &rxreq, NETIF_RSP_OKAY, NET_IP_ALIGN, size, 0); 266 267 return size; 268 } 269 270 /* ------------------------------------------------------------- */ 271 272 static NetClientInfo net_xen_info = { 273 .type = NET_CLIENT_OPTIONS_KIND_NIC, 274 .size = sizeof(NICState), 275 .receive = net_rx_packet, 276 }; 277 278 static int net_init(struct XenDevice *xendev) 279 { 280 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 281 282 /* read xenstore entries */ 283 if (netdev->mac == NULL) { 284 netdev->mac = xenstore_read_be_str(&netdev->xendev, "mac"); 285 } 286 287 /* do we have all we need? */ 288 if (netdev->mac == NULL) { 289 return -1; 290 } 291 292 if (net_parse_macaddr(netdev->conf.macaddr.a, netdev->mac) < 0) { 293 return -1; 294 } 295 296 netdev->nic = qemu_new_nic(&net_xen_info, &netdev->conf, 297 "xen", NULL, netdev); 298 299 snprintf(qemu_get_queue(netdev->nic)->info_str, 300 sizeof(qemu_get_queue(netdev->nic)->info_str), 301 "nic: xenbus vif macaddr=%s", netdev->mac); 302 303 /* fill info */ 304 xenstore_write_be_int(&netdev->xendev, "feature-rx-copy", 1); 305 xenstore_write_be_int(&netdev->xendev, "feature-rx-flip", 0); 306 307 return 0; 308 } 309 310 static int net_connect(struct XenDevice *xendev) 311 { 312 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 313 int rx_copy; 314 315 if (xenstore_read_fe_int(&netdev->xendev, "tx-ring-ref", 316 &netdev->tx_ring_ref) == -1) { 317 return -1; 318 } 319 if (xenstore_read_fe_int(&netdev->xendev, "rx-ring-ref", 320 &netdev->rx_ring_ref) == -1) { 321 return 1; 322 } 323 if (xenstore_read_fe_int(&netdev->xendev, "event-channel", 324 &netdev->xendev.remote_port) == -1) { 325 return -1; 326 } 327 328 if (xenstore_read_fe_int(&netdev->xendev, "request-rx-copy", &rx_copy) == -1) { 329 rx_copy = 0; 330 } 331 if (rx_copy == 0) { 332 xen_be_printf(&netdev->xendev, 0, "frontend doesn't support rx-copy.\n"); 333 return -1; 334 } 335 336 netdev->txs = xengnttab_map_grant_ref(netdev->xendev.gnttabdev, 337 netdev->xendev.dom, 338 netdev->tx_ring_ref, 339 PROT_READ | PROT_WRITE); 340 if (!netdev->txs) { 341 return -1; 342 } 343 netdev->rxs = xengnttab_map_grant_ref(netdev->xendev.gnttabdev, 344 netdev->xendev.dom, 345 netdev->rx_ring_ref, 346 PROT_READ | PROT_WRITE); 347 if (!netdev->rxs) { 348 xengnttab_unmap(netdev->xendev.gnttabdev, netdev->txs, 1); 349 netdev->txs = NULL; 350 return -1; 351 } 352 BACK_RING_INIT(&netdev->tx_ring, netdev->txs, XC_PAGE_SIZE); 353 BACK_RING_INIT(&netdev->rx_ring, netdev->rxs, XC_PAGE_SIZE); 354 355 xen_be_bind_evtchn(&netdev->xendev); 356 357 xen_be_printf(&netdev->xendev, 1, "ok: tx-ring-ref %d, rx-ring-ref %d, " 358 "remote port %d, local port %d\n", 359 netdev->tx_ring_ref, netdev->rx_ring_ref, 360 netdev->xendev.remote_port, netdev->xendev.local_port); 361 362 net_tx_packets(netdev); 363 return 0; 364 } 365 366 static void net_disconnect(struct XenDevice *xendev) 367 { 368 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 369 370 xen_be_unbind_evtchn(&netdev->xendev); 371 372 if (netdev->txs) { 373 xengnttab_unmap(netdev->xendev.gnttabdev, netdev->txs, 1); 374 netdev->txs = NULL; 375 } 376 if (netdev->rxs) { 377 xengnttab_unmap(netdev->xendev.gnttabdev, netdev->rxs, 1); 378 netdev->rxs = NULL; 379 } 380 } 381 382 static void net_event(struct XenDevice *xendev) 383 { 384 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 385 net_tx_packets(netdev); 386 qemu_flush_queued_packets(qemu_get_queue(netdev->nic)); 387 } 388 389 static int net_free(struct XenDevice *xendev) 390 { 391 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 392 393 if (netdev->nic) { 394 qemu_del_nic(netdev->nic); 395 netdev->nic = NULL; 396 } 397 g_free(netdev->mac); 398 netdev->mac = NULL; 399 return 0; 400 } 401 402 /* ------------------------------------------------------------- */ 403 404 struct XenDevOps xen_netdev_ops = { 405 .size = sizeof(struct XenNetDev), 406 .flags = DEVOPS_FLAG_NEED_GNTDEV, 407 .init = net_init, 408 .initialise = net_connect, 409 .event = net_event, 410 .disconnect = net_disconnect, 411 .free = net_free, 412 }; 413