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_be_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_be_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_be_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_be_printf(&netdev->xendev, 0, "bad packet size: %d\n", txreq.size); 144 net_tx_error(netdev, &txreq, rc); 145 continue; 146 } 147 148 if ((txreq.offset + txreq.size) > XC_PAGE_SIZE) { 149 xen_be_printf(&netdev->xendev, 0, "error: page crossing\n"); 150 net_tx_error(netdev, &txreq, rc); 151 continue; 152 } 153 154 xen_be_printf(&netdev->xendev, 3, "tx packet ref %d, off %d, len %d, flags 0x%x%s%s%s%s\n", 155 txreq.gref, txreq.offset, txreq.size, txreq.flags, 156 (txreq.flags & NETTXF_csum_blank) ? " csum_blank" : "", 157 (txreq.flags & NETTXF_data_validated) ? " data_validated" : "", 158 (txreq.flags & NETTXF_more_data) ? " more_data" : "", 159 (txreq.flags & NETTXF_extra_info) ? " extra_info" : ""); 160 161 page = xengnttab_map_grant_ref(netdev->xendev.gnttabdev, 162 netdev->xendev.dom, 163 txreq.gref, PROT_READ); 164 if (page == NULL) { 165 xen_be_printf(&netdev->xendev, 0, "error: tx gref dereference failed (%d)\n", 166 txreq.gref); 167 net_tx_error(netdev, &txreq, rc); 168 continue; 169 } 170 if (txreq.flags & NETTXF_csum_blank) { 171 /* have read-only mapping -> can't fill checksum in-place */ 172 if (!tmpbuf) { 173 tmpbuf = g_malloc(XC_PAGE_SIZE); 174 } 175 memcpy(tmpbuf, page + txreq.offset, txreq.size); 176 net_checksum_calculate(tmpbuf, txreq.size); 177 qemu_send_packet(qemu_get_queue(netdev->nic), tmpbuf, 178 txreq.size); 179 } else { 180 qemu_send_packet(qemu_get_queue(netdev->nic), 181 page + txreq.offset, txreq.size); 182 } 183 xengnttab_unmap(netdev->xendev.gnttabdev, page, 1); 184 net_tx_response(netdev, &txreq, NETIF_RSP_OKAY); 185 } 186 if (!netdev->tx_work) { 187 break; 188 } 189 netdev->tx_work = 0; 190 } 191 g_free(tmpbuf); 192 } 193 194 /* ------------------------------------------------------------- */ 195 196 static void net_rx_response(struct XenNetDev *netdev, 197 netif_rx_request_t *req, int8_t st, 198 uint16_t offset, uint16_t size, 199 uint16_t flags) 200 { 201 RING_IDX i = netdev->rx_ring.rsp_prod_pvt; 202 netif_rx_response_t *resp; 203 int notify; 204 205 resp = RING_GET_RESPONSE(&netdev->rx_ring, i); 206 resp->offset = offset; 207 resp->flags = flags; 208 resp->id = req->id; 209 resp->status = (int16_t)size; 210 if (st < 0) { 211 resp->status = (int16_t)st; 212 } 213 214 xen_be_printf(&netdev->xendev, 3, "rx response: idx %d, status %d, flags 0x%x\n", 215 i, resp->status, resp->flags); 216 217 netdev->rx_ring.rsp_prod_pvt = ++i; 218 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->rx_ring, notify); 219 if (notify) { 220 xen_be_send_notify(&netdev->xendev); 221 } 222 } 223 224 #define NET_IP_ALIGN 2 225 226 static ssize_t net_rx_packet(NetClientState *nc, const uint8_t *buf, size_t size) 227 { 228 struct XenNetDev *netdev = qemu_get_nic_opaque(nc); 229 netif_rx_request_t rxreq; 230 RING_IDX rc, rp; 231 void *page; 232 233 if (netdev->xendev.be_state != XenbusStateConnected) { 234 return -1; 235 } 236 237 rc = netdev->rx_ring.req_cons; 238 rp = netdev->rx_ring.sring->req_prod; 239 xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ 240 241 if (rc == rp || RING_REQUEST_CONS_OVERFLOW(&netdev->rx_ring, rc)) { 242 return 0; 243 } 244 if (size > XC_PAGE_SIZE - NET_IP_ALIGN) { 245 xen_be_printf(&netdev->xendev, 0, "packet too big (%lu > %ld)", 246 (unsigned long)size, XC_PAGE_SIZE - NET_IP_ALIGN); 247 return -1; 248 } 249 250 memcpy(&rxreq, RING_GET_REQUEST(&netdev->rx_ring, rc), sizeof(rxreq)); 251 netdev->rx_ring.req_cons = ++rc; 252 253 page = xengnttab_map_grant_ref(netdev->xendev.gnttabdev, 254 netdev->xendev.dom, 255 rxreq.gref, PROT_WRITE); 256 if (page == NULL) { 257 xen_be_printf(&netdev->xendev, 0, "error: rx gref dereference failed (%d)\n", 258 rxreq.gref); 259 net_rx_response(netdev, &rxreq, NETIF_RSP_ERROR, 0, 0, 0); 260 return -1; 261 } 262 memcpy(page + NET_IP_ALIGN, buf, size); 263 xengnttab_unmap(netdev->xendev.gnttabdev, page, 1); 264 net_rx_response(netdev, &rxreq, NETIF_RSP_OKAY, NET_IP_ALIGN, size, 0); 265 266 return size; 267 } 268 269 /* ------------------------------------------------------------- */ 270 271 static NetClientInfo net_xen_info = { 272 .type = NET_CLIENT_OPTIONS_KIND_NIC, 273 .size = sizeof(NICState), 274 .receive = net_rx_packet, 275 }; 276 277 static int net_init(struct XenDevice *xendev) 278 { 279 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 280 281 /* read xenstore entries */ 282 if (netdev->mac == NULL) { 283 netdev->mac = xenstore_read_be_str(&netdev->xendev, "mac"); 284 } 285 286 /* do we have all we need? */ 287 if (netdev->mac == NULL) { 288 return -1; 289 } 290 291 if (net_parse_macaddr(netdev->conf.macaddr.a, netdev->mac) < 0) { 292 return -1; 293 } 294 295 netdev->nic = qemu_new_nic(&net_xen_info, &netdev->conf, 296 "xen", NULL, netdev); 297 298 snprintf(qemu_get_queue(netdev->nic)->info_str, 299 sizeof(qemu_get_queue(netdev->nic)->info_str), 300 "nic: xenbus vif macaddr=%s", netdev->mac); 301 302 /* fill info */ 303 xenstore_write_be_int(&netdev->xendev, "feature-rx-copy", 1); 304 xenstore_write_be_int(&netdev->xendev, "feature-rx-flip", 0); 305 306 return 0; 307 } 308 309 static int net_connect(struct XenDevice *xendev) 310 { 311 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 312 int rx_copy; 313 314 if (xenstore_read_fe_int(&netdev->xendev, "tx-ring-ref", 315 &netdev->tx_ring_ref) == -1) { 316 return -1; 317 } 318 if (xenstore_read_fe_int(&netdev->xendev, "rx-ring-ref", 319 &netdev->rx_ring_ref) == -1) { 320 return 1; 321 } 322 if (xenstore_read_fe_int(&netdev->xendev, "event-channel", 323 &netdev->xendev.remote_port) == -1) { 324 return -1; 325 } 326 327 if (xenstore_read_fe_int(&netdev->xendev, "request-rx-copy", &rx_copy) == -1) { 328 rx_copy = 0; 329 } 330 if (rx_copy == 0) { 331 xen_be_printf(&netdev->xendev, 0, "frontend doesn't support rx-copy.\n"); 332 return -1; 333 } 334 335 netdev->txs = xengnttab_map_grant_ref(netdev->xendev.gnttabdev, 336 netdev->xendev.dom, 337 netdev->tx_ring_ref, 338 PROT_READ | PROT_WRITE); 339 if (!netdev->txs) { 340 return -1; 341 } 342 netdev->rxs = xengnttab_map_grant_ref(netdev->xendev.gnttabdev, 343 netdev->xendev.dom, 344 netdev->rx_ring_ref, 345 PROT_READ | PROT_WRITE); 346 if (!netdev->rxs) { 347 xengnttab_unmap(netdev->xendev.gnttabdev, netdev->txs, 1); 348 netdev->txs = NULL; 349 return -1; 350 } 351 BACK_RING_INIT(&netdev->tx_ring, netdev->txs, XC_PAGE_SIZE); 352 BACK_RING_INIT(&netdev->rx_ring, netdev->rxs, XC_PAGE_SIZE); 353 354 xen_be_bind_evtchn(&netdev->xendev); 355 356 xen_be_printf(&netdev->xendev, 1, "ok: tx-ring-ref %d, rx-ring-ref %d, " 357 "remote port %d, local port %d\n", 358 netdev->tx_ring_ref, netdev->rx_ring_ref, 359 netdev->xendev.remote_port, netdev->xendev.local_port); 360 361 net_tx_packets(netdev); 362 return 0; 363 } 364 365 static void net_disconnect(struct XenDevice *xendev) 366 { 367 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 368 369 xen_be_unbind_evtchn(&netdev->xendev); 370 371 if (netdev->txs) { 372 xengnttab_unmap(netdev->xendev.gnttabdev, netdev->txs, 1); 373 netdev->txs = NULL; 374 } 375 if (netdev->rxs) { 376 xengnttab_unmap(netdev->xendev.gnttabdev, netdev->rxs, 1); 377 netdev->rxs = NULL; 378 } 379 } 380 381 static void net_event(struct XenDevice *xendev) 382 { 383 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 384 net_tx_packets(netdev); 385 qemu_flush_queued_packets(qemu_get_queue(netdev->nic)); 386 } 387 388 static int net_free(struct XenDevice *xendev) 389 { 390 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 391 392 if (netdev->nic) { 393 qemu_del_nic(netdev->nic); 394 netdev->nic = NULL; 395 } 396 g_free(netdev->mac); 397 netdev->mac = NULL; 398 return 0; 399 } 400 401 /* ------------------------------------------------------------- */ 402 403 struct XenDevOps xen_netdev_ops = { 404 .size = sizeof(struct XenNetDev), 405 .flags = DEVOPS_FLAG_NEED_GNTDEV, 406 .init = net_init, 407 .initialise = net_connect, 408 .event = net_event, 409 .disconnect = net_disconnect, 410 .free = net_free, 411 }; 412