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