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, write to the Free Software Foundation, Inc., 17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 18 */ 19 20 #include <stdio.h> 21 #include <stdlib.h> 22 #include <stdarg.h> 23 #include <string.h> 24 #include <unistd.h> 25 #include <signal.h> 26 #include <inttypes.h> 27 #include <fcntl.h> 28 #include <errno.h> 29 #include <pthread.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 <xs.h> 38 #include <xenctrl.h> 39 #include <xen/io/xenbus.h> 40 #include <xen/io/netif.h> 41 42 #include "hw.h" 43 #include "net.h" 44 #include "qemu-char.h" 45 #include "xen_backend.h" 46 47 /* ------------------------------------------------------------- */ 48 49 struct XenNetDev { 50 struct XenDevice xendev; /* must be first */ 51 char *mac; 52 int tx_work; 53 int tx_ring_ref; 54 int rx_ring_ref; 55 struct netif_tx_sring *txs; 56 struct netif_rx_sring *rxs; 57 netif_tx_back_ring_t tx_ring; 58 netif_rx_back_ring_t rx_ring; 59 VLANClientState *vs; 60 }; 61 62 /* ------------------------------------------------------------- */ 63 64 static void net_tx_response(struct XenNetDev *netdev, netif_tx_request_t *txp, int8_t st) 65 { 66 RING_IDX i = netdev->tx_ring.rsp_prod_pvt; 67 netif_tx_response_t *resp; 68 int notify; 69 70 resp = RING_GET_RESPONSE(&netdev->tx_ring, i); 71 resp->id = txp->id; 72 resp->status = st; 73 74 #if 0 75 if (txp->flags & NETTXF_extra_info) 76 RING_GET_RESPONSE(&netdev->tx_ring, ++i)->status = NETIF_RSP_NULL; 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 if (i == netdev->tx_ring.req_cons) { 85 int more_to_do; 86 RING_FINAL_CHECK_FOR_REQUESTS(&netdev->tx_ring, more_to_do); 87 if (more_to_do) 88 netdev->tx_work++; 89 } 90 } 91 92 static void net_tx_error(struct XenNetDev *netdev, netif_tx_request_t *txp, RING_IDX end) 93 { 94 #if 0 95 /* 96 * Hmm, why netback fails everything in the ring? 97 * Should we do that even when not supporting SG and TSO? 98 */ 99 RING_IDX cons = netdev->tx_ring.req_cons; 100 101 do { 102 make_tx_response(netif, txp, NETIF_RSP_ERROR); 103 if (cons >= end) 104 break; 105 txp = RING_GET_REQUEST(&netdev->tx_ring, cons++); 106 } while (1); 107 netdev->tx_ring.req_cons = cons; 108 netif_schedule_work(netif); 109 netif_put(netif); 110 #else 111 net_tx_response(netdev, txp, NETIF_RSP_ERROR); 112 #endif 113 } 114 115 static void net_tx_packets(struct XenNetDev *netdev) 116 { 117 netif_tx_request_t txreq; 118 RING_IDX rc, rp; 119 void *page; 120 void *tmpbuf = NULL; 121 122 for (;;) { 123 rc = netdev->tx_ring.req_cons; 124 rp = netdev->tx_ring.sring->req_prod; 125 xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ 126 127 while ((rc != rp)) { 128 if (RING_REQUEST_CONS_OVERFLOW(&netdev->tx_ring, rc)) 129 break; 130 memcpy(&txreq, RING_GET_REQUEST(&netdev->tx_ring, rc), sizeof(txreq)); 131 netdev->tx_ring.req_cons = ++rc; 132 133 #if 1 134 /* should not happen in theory, we don't announce the * 135 * feature-{sg,gso,whatelse} flags in xenstore (yet?) */ 136 if (txreq.flags & NETTXF_extra_info) { 137 xen_be_printf(&netdev->xendev, 0, "FIXME: extra info flag\n"); 138 net_tx_error(netdev, &txreq, rc); 139 continue; 140 } 141 if (txreq.flags & NETTXF_more_data) { 142 xen_be_printf(&netdev->xendev, 0, "FIXME: more data flag\n"); 143 net_tx_error(netdev, &txreq, rc); 144 continue; 145 } 146 #endif 147 148 if (txreq.size < 14) { 149 xen_be_printf(&netdev->xendev, 0, "bad packet size: %d\n", txreq.size); 150 net_tx_error(netdev, &txreq, rc); 151 continue; 152 } 153 154 if ((txreq.offset + txreq.size) > XC_PAGE_SIZE) { 155 xen_be_printf(&netdev->xendev, 0, "error: page crossing\n"); 156 net_tx_error(netdev, &txreq, rc); 157 continue; 158 } 159 160 xen_be_printf(&netdev->xendev, 3, "tx packet ref %d, off %d, len %d, flags 0x%x%s%s%s%s\n", 161 txreq.gref, txreq.offset, txreq.size, txreq.flags, 162 (txreq.flags & NETTXF_csum_blank) ? " csum_blank" : "", 163 (txreq.flags & NETTXF_data_validated) ? " data_validated" : "", 164 (txreq.flags & NETTXF_more_data) ? " more_data" : "", 165 (txreq.flags & NETTXF_extra_info) ? " extra_info" : ""); 166 167 page = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, 168 netdev->xendev.dom, 169 txreq.gref, PROT_READ); 170 if (page == NULL) { 171 xen_be_printf(&netdev->xendev, 0, "error: tx gref dereference failed (%d)\n", 172 txreq.gref); 173 net_tx_error(netdev, &txreq, rc); 174 continue; 175 } 176 if (txreq.flags & NETTXF_csum_blank) { 177 /* have read-only mapping -> can't fill checksum in-place */ 178 if (!tmpbuf) 179 tmpbuf = qemu_malloc(XC_PAGE_SIZE); 180 memcpy(tmpbuf, page + txreq.offset, txreq.size); 181 net_checksum_calculate(tmpbuf, txreq.size); 182 qemu_send_packet(netdev->vs, tmpbuf, txreq.size); 183 } else { 184 qemu_send_packet(netdev->vs, page + txreq.offset, txreq.size); 185 } 186 xc_gnttab_munmap(netdev->xendev.gnttabdev, page, 1); 187 net_tx_response(netdev, &txreq, NETIF_RSP_OKAY); 188 } 189 if (!netdev->tx_work) 190 break; 191 netdev->tx_work = 0; 192 } 193 qemu_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 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 #define NET_IP_ALIGN 2 225 226 static int net_rx_ok(VLANClientState *vc) 227 { 228 struct XenNetDev *netdev = vc->opaque; 229 RING_IDX rc, rp; 230 231 if (netdev->xendev.be_state != XenbusStateConnected) 232 return 0; 233 234 rc = netdev->rx_ring.req_cons; 235 rp = netdev->rx_ring.sring->req_prod; 236 xen_rmb(); 237 238 if (rc == rp || RING_REQUEST_CONS_OVERFLOW(&netdev->rx_ring, rc)) { 239 xen_be_printf(&netdev->xendev, 2, "%s: no rx buffers (%d/%d)\n", 240 __FUNCTION__, rc, rp); 241 return 0; 242 } 243 return 1; 244 } 245 246 static ssize_t net_rx_packet(VLANClientState *vc, const uint8_t *buf, size_t size) 247 { 248 struct XenNetDev *netdev = vc->opaque; 249 netif_rx_request_t rxreq; 250 RING_IDX rc, rp; 251 void *page; 252 253 if (netdev->xendev.be_state != XenbusStateConnected) 254 return -1; 255 256 rc = netdev->rx_ring.req_cons; 257 rp = netdev->rx_ring.sring->req_prod; 258 xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ 259 260 if (rc == rp || RING_REQUEST_CONS_OVERFLOW(&netdev->rx_ring, rc)) { 261 xen_be_printf(&netdev->xendev, 2, "no buffer, drop packet\n"); 262 return -1; 263 } 264 if (size > XC_PAGE_SIZE - NET_IP_ALIGN) { 265 xen_be_printf(&netdev->xendev, 0, "packet too big (%lu > %ld)", 266 (unsigned long)size, XC_PAGE_SIZE - NET_IP_ALIGN); 267 return -1; 268 } 269 270 memcpy(&rxreq, RING_GET_REQUEST(&netdev->rx_ring, rc), sizeof(rxreq)); 271 netdev->rx_ring.req_cons = ++rc; 272 273 page = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, 274 netdev->xendev.dom, 275 rxreq.gref, PROT_WRITE); 276 if (page == NULL) { 277 xen_be_printf(&netdev->xendev, 0, "error: rx gref dereference failed (%d)\n", 278 rxreq.gref); 279 net_rx_response(netdev, &rxreq, NETIF_RSP_ERROR, 0, 0, 0); 280 return -1; 281 } 282 memcpy(page + NET_IP_ALIGN, buf, size); 283 xc_gnttab_munmap(netdev->xendev.gnttabdev, page, 1); 284 net_rx_response(netdev, &rxreq, NETIF_RSP_OKAY, NET_IP_ALIGN, size, 0); 285 286 return size; 287 } 288 289 /* ------------------------------------------------------------- */ 290 291 static int net_init(struct XenDevice *xendev) 292 { 293 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 294 VLANState *vlan; 295 296 /* read xenstore entries */ 297 if (netdev->mac == NULL) 298 netdev->mac = xenstore_read_be_str(&netdev->xendev, "mac"); 299 300 /* do we have all we need? */ 301 if (netdev->mac == NULL) 302 return -1; 303 304 vlan = qemu_find_vlan(netdev->xendev.dev, 1); 305 netdev->vs = qemu_new_vlan_client(vlan, "xen", NULL, 306 net_rx_ok, net_rx_packet, NULL, 307 NULL, netdev); 308 snprintf(netdev->vs->info_str, sizeof(netdev->vs->info_str), 309 "nic: xenbus vif macaddr=%s", netdev->mac); 310 311 /* fill info */ 312 xenstore_write_be_int(&netdev->xendev, "feature-rx-copy", 1); 313 xenstore_write_be_int(&netdev->xendev, "feature-rx-flip", 0); 314 315 return 0; 316 } 317 318 static int net_connect(struct XenDevice *xendev) 319 { 320 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 321 int rx_copy; 322 323 if (xenstore_read_fe_int(&netdev->xendev, "tx-ring-ref", 324 &netdev->tx_ring_ref) == -1) 325 return -1; 326 if (xenstore_read_fe_int(&netdev->xendev, "rx-ring-ref", 327 &netdev->rx_ring_ref) == -1) 328 return 1; 329 if (xenstore_read_fe_int(&netdev->xendev, "event-channel", 330 &netdev->xendev.remote_port) == -1) 331 return -1; 332 333 if (xenstore_read_fe_int(&netdev->xendev, "request-rx-copy", &rx_copy) == -1) 334 rx_copy = 0; 335 if (rx_copy == 0) { 336 xen_be_printf(&netdev->xendev, 0, "frontend doesn't support rx-copy.\n"); 337 return -1; 338 } 339 340 netdev->txs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, 341 netdev->xendev.dom, 342 netdev->tx_ring_ref, 343 PROT_READ | PROT_WRITE); 344 netdev->rxs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, 345 netdev->xendev.dom, 346 netdev->rx_ring_ref, 347 PROT_READ | PROT_WRITE); 348 if (!netdev->txs || !netdev->rxs) 349 return -1; 350 BACK_RING_INIT(&netdev->tx_ring, netdev->txs, XC_PAGE_SIZE); 351 BACK_RING_INIT(&netdev->rx_ring, netdev->rxs, XC_PAGE_SIZE); 352 353 xen_be_bind_evtchn(&netdev->xendev); 354 355 xen_be_printf(&netdev->xendev, 1, "ok: tx-ring-ref %d, rx-ring-ref %d, " 356 "remote port %d, local port %d\n", 357 netdev->tx_ring_ref, netdev->rx_ring_ref, 358 netdev->xendev.remote_port, netdev->xendev.local_port); 359 360 net_tx_packets(netdev); 361 return 0; 362 } 363 364 static void net_disconnect(struct XenDevice *xendev) 365 { 366 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 367 368 xen_be_unbind_evtchn(&netdev->xendev); 369 370 if (netdev->txs) { 371 xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->txs, 1); 372 netdev->txs = NULL; 373 } 374 if (netdev->rxs) { 375 xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->rxs, 1); 376 netdev->rxs = NULL; 377 } 378 if (netdev->vs) { 379 qemu_del_vlan_client(netdev->vs); 380 netdev->vs = NULL; 381 } 382 } 383 384 static void net_event(struct XenDevice *xendev) 385 { 386 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 387 net_tx_packets(netdev); 388 } 389 390 static int net_free(struct XenDevice *xendev) 391 { 392 struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); 393 394 qemu_free(netdev->mac); 395 return 0; 396 } 397 398 /* ------------------------------------------------------------- */ 399 400 struct XenDevOps xen_netdev_ops = { 401 .size = sizeof(struct XenNetDev), 402 .flags = DEVOPS_FLAG_NEED_GNTDEV, 403 .init = net_init, 404 .connect = net_connect, 405 .event = net_event, 406 .disconnect = net_disconnect, 407 .free = net_free, 408 }; 409