1 /* 2 * Copyright (C) 2014-2018 Vincenzo Maffione, Luigi Rizzo. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26 /* 27 * $FreeBSD$ 28 */ 29 30 #include <net/netmap.h> 31 #include <sys/selinfo.h> 32 #include <vm/vm.h> 33 #include <vm/pmap.h> /* vtophys ? */ 34 #include <dev/netmap/netmap_kern.h> 35 36 /* 37 * Return 1 if the queue identified by 't' and 'idx' is in netmap mode. 38 */ 39 static int 40 vtnet_netmap_queue_on(struct vtnet_softc *sc, enum txrx t, int idx) 41 { 42 struct netmap_adapter *na = NA(sc->vtnet_ifp); 43 44 if (!nm_native_on(na)) 45 return 0; 46 47 if (t == NR_RX) 48 return !!(idx < na->num_rx_rings && 49 na->rx_rings[idx]->nr_mode == NKR_NETMAP_ON); 50 51 return !!(idx < na->num_tx_rings && 52 na->tx_rings[idx]->nr_mode == NKR_NETMAP_ON); 53 } 54 55 /* Register and unregister. */ 56 static int 57 vtnet_netmap_reg(struct netmap_adapter *na, int state) 58 { 59 struct ifnet *ifp = na->ifp; 60 struct vtnet_softc *sc = ifp->if_softc; 61 int success; 62 int i; 63 64 /* Drain the taskqueues to make sure that there are no worker threads 65 * accessing the virtqueues. */ 66 vtnet_drain_taskqueues(sc); 67 68 VTNET_CORE_LOCK(sc); 69 70 /* We need nm_netmap_on() to return true when called by 71 * vtnet_init_locked() below. */ 72 if (state) 73 nm_set_native_flags(na); 74 75 /* We need to trigger a device reset in order to unexpose guest buffers 76 * published to the host. */ 77 ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE); 78 /* Get pending used buffers. The way they are freed depends on whether 79 * they are netmap buffer or they are mbufs. We can tell apart the two 80 * cases by looking at kring->nr_mode, before this is possibly updated 81 * in the loop below. */ 82 for (i = 0; i < sc->vtnet_act_vq_pairs; i++) { 83 struct vtnet_txq *txq = &sc->vtnet_txqs[i]; 84 struct vtnet_rxq *rxq = &sc->vtnet_rxqs[i]; 85 86 VTNET_TXQ_LOCK(txq); 87 vtnet_txq_free_mbufs(txq); 88 VTNET_TXQ_UNLOCK(txq); 89 90 VTNET_RXQ_LOCK(rxq); 91 vtnet_rxq_free_mbufs(rxq); 92 VTNET_RXQ_UNLOCK(rxq); 93 } 94 vtnet_init_locked(sc); 95 success = (ifp->if_drv_flags & IFF_DRV_RUNNING) ? 0 : ENXIO; 96 97 if (state) { 98 netmap_krings_mode_commit(na, state); 99 } else { 100 nm_clear_native_flags(na); 101 netmap_krings_mode_commit(na, state); 102 } 103 104 VTNET_CORE_UNLOCK(sc); 105 106 return success; 107 } 108 109 110 /* Reconcile kernel and user view of the transmit ring. */ 111 static int 112 vtnet_netmap_txsync(struct netmap_kring *kring, int flags) 113 { 114 struct netmap_adapter *na = kring->na; 115 struct ifnet *ifp = na->ifp; 116 struct netmap_ring *ring = kring->ring; 117 u_int ring_nr = kring->ring_id; 118 u_int nm_i; /* index into the netmap ring */ 119 u_int const lim = kring->nkr_num_slots - 1; 120 u_int const head = kring->rhead; 121 122 /* device-specific */ 123 struct vtnet_softc *sc = ifp->if_softc; 124 struct vtnet_txq *txq = &sc->vtnet_txqs[ring_nr]; 125 struct virtqueue *vq = txq->vtntx_vq; 126 int interrupts = !(kring->nr_kflags & NKR_NOINTR); 127 u_int n; 128 129 /* 130 * First part: process new packets to send. 131 */ 132 rmb(); 133 134 nm_i = kring->nr_hwcur; 135 if (nm_i != head) { /* we have new packets to send */ 136 struct sglist *sg = txq->vtntx_sg; 137 138 for (; nm_i != head; nm_i = nm_next(nm_i, lim)) { 139 /* we use an empty header here */ 140 struct netmap_slot *slot = &ring->slot[nm_i]; 141 u_int len = slot->len; 142 uint64_t paddr; 143 void *addr = PNMB(na, slot, &paddr); 144 int err; 145 146 NM_CHECK_ADDR_LEN(na, addr, len); 147 148 slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED); 149 /* Initialize the scatterlist, expose it to the hypervisor, 150 * and kick the hypervisor (if necessary). 151 */ 152 sglist_reset(sg); // cheap 153 err = sglist_append(sg, &txq->vtntx_shrhdr, sc->vtnet_hdr_size); 154 err |= sglist_append_phys(sg, paddr, len); 155 KASSERT(err == 0, ("%s: cannot append to sglist %d", 156 __func__, err)); 157 err = virtqueue_enqueue(vq, /*cookie=*/txq, sg, 158 /*readable=*/sg->sg_nseg, 159 /*writeable=*/0); 160 if (unlikely(err)) { 161 if (err != ENOSPC) 162 nm_prerr("virtqueue_enqueue(%s) failed: %d", 163 kring->name, err); 164 break; 165 } 166 } 167 168 virtqueue_notify(vq); 169 170 /* Update hwcur depending on where we stopped. */ 171 kring->nr_hwcur = nm_i; /* note we migth break early */ 172 } 173 174 /* Free used slots. We only consider our own used buffers, recognized 175 * by the token we passed to virtqueue_enqueue. 176 */ 177 n = 0; 178 for (;;) { 179 void *token = virtqueue_dequeue(vq, NULL); 180 if (token == NULL) 181 break; 182 if (unlikely(token != (void *)txq)) 183 nm_prerr("BUG: TX token mismatch"); 184 else 185 n++; 186 } 187 if (n > 0) { 188 kring->nr_hwtail += n; 189 if (kring->nr_hwtail > lim) 190 kring->nr_hwtail -= lim + 1; 191 } 192 193 if (interrupts && virtqueue_nfree(vq) < 32) 194 virtqueue_postpone_intr(vq, VQ_POSTPONE_LONG); 195 196 return 0; 197 } 198 199 /* 200 * Publish (up to) num netmap receive buffers to the host, 201 * starting from the first one that the user made available 202 * (kring->nr_hwcur). 203 */ 204 static int 205 vtnet_netmap_kring_refill(struct netmap_kring *kring, u_int num) 206 { 207 struct netmap_adapter *na = kring->na; 208 struct ifnet *ifp = na->ifp; 209 struct netmap_ring *ring = kring->ring; 210 u_int ring_nr = kring->ring_id; 211 u_int const lim = kring->nkr_num_slots - 1; 212 u_int nm_i = kring->nr_hwcur; 213 214 /* device-specific */ 215 struct vtnet_softc *sc = ifp->if_softc; 216 struct vtnet_rxq *rxq = &sc->vtnet_rxqs[ring_nr]; 217 struct virtqueue *vq = rxq->vtnrx_vq; 218 219 /* use a local sglist, default might be short */ 220 struct sglist_seg ss[2]; 221 struct sglist sg = { ss, 0, 0, 2 }; 222 223 for (; num > 0; nm_i = nm_next(nm_i, lim), num--) { 224 struct netmap_slot *slot = &ring->slot[nm_i]; 225 uint64_t paddr; 226 void *addr = PNMB(na, slot, &paddr); 227 int err; 228 229 if (addr == NETMAP_BUF_BASE(na)) { /* bad buf */ 230 if (netmap_ring_reinit(kring)) 231 return -1; 232 } 233 234 slot->flags &= ~NS_BUF_CHANGED; 235 sglist_reset(&sg); 236 err = sglist_append(&sg, &rxq->vtnrx_shrhdr, sc->vtnet_hdr_size); 237 err |= sglist_append_phys(&sg, paddr, NETMAP_BUF_SIZE(na)); 238 KASSERT(err == 0, ("%s: cannot append to sglist %d", 239 __func__, err)); 240 /* writable for the host */ 241 err = virtqueue_enqueue(vq, /*cookie=*/rxq, &sg, 242 /*readable=*/0, /*writeable=*/sg.sg_nseg); 243 if (unlikely(err)) { 244 if (err != ENOSPC) 245 nm_prerr("virtqueue_enqueue(%s) failed: %d", 246 kring->name, err); 247 break; 248 } 249 } 250 251 return nm_i; 252 } 253 254 /* 255 * Publish netmap buffers on a RX virtqueue. 256 * Returns -1 if this virtqueue is not being opened in netmap mode. 257 * If the virtqueue is being opened in netmap mode, return 0 on success and 258 * a positive error code on failure. 259 */ 260 static int 261 vtnet_netmap_rxq_populate(struct vtnet_rxq *rxq) 262 { 263 struct netmap_adapter *na = NA(rxq->vtnrx_sc->vtnet_ifp); 264 struct netmap_kring *kring; 265 int error; 266 267 if (!nm_native_on(na) || rxq->vtnrx_id >= na->num_rx_rings) 268 return -1; 269 270 kring = na->rx_rings[rxq->vtnrx_id]; 271 if (!(nm_kring_pending_on(kring) || 272 kring->nr_pending_mode == NKR_NETMAP_ON)) 273 return -1; 274 275 /* Expose all the RX netmap buffers we can. In case of no indirect 276 * buffers, the number of netmap slots in the RX ring matches the 277 * maximum number of 2-elements sglist that the RX virtqueue can 278 * accommodate. */ 279 error = vtnet_netmap_kring_refill(kring, na->num_rx_desc); 280 virtqueue_notify(rxq->vtnrx_vq); 281 282 return error < 0 ? ENXIO : 0; 283 } 284 285 /* Reconcile kernel and user view of the receive ring. */ 286 static int 287 vtnet_netmap_rxsync(struct netmap_kring *kring, int flags) 288 { 289 struct netmap_adapter *na = kring->na; 290 struct ifnet *ifp = na->ifp; 291 struct netmap_ring *ring = kring->ring; 292 u_int ring_nr = kring->ring_id; 293 u_int nm_i; /* index into the netmap ring */ 294 u_int const lim = kring->nkr_num_slots - 1; 295 u_int const head = kring->rhead; 296 int force_update = (flags & NAF_FORCE_READ) || 297 (kring->nr_kflags & NKR_PENDINTR); 298 int interrupts = !(kring->nr_kflags & NKR_NOINTR); 299 300 /* device-specific */ 301 struct vtnet_softc *sc = ifp->if_softc; 302 struct vtnet_rxq *rxq = &sc->vtnet_rxqs[ring_nr]; 303 struct virtqueue *vq = rxq->vtnrx_vq; 304 305 rmb(); 306 /* 307 * First part: import newly received packets. 308 * Only accept our own buffers (matching the token). We should only get 309 * matching buffers. We may need to stop early to avoid hwtail to overrun 310 * hwcur. 311 */ 312 if (netmap_no_pendintr || force_update) { 313 uint32_t hwtail_lim = nm_prev(kring->nr_hwcur, lim); 314 void *token; 315 316 vtnet_rxq_disable_intr(rxq); 317 318 nm_i = kring->nr_hwtail; 319 while (nm_i != hwtail_lim) { 320 int len; 321 token = virtqueue_dequeue(vq, &len); 322 if (token == NULL) { 323 if (interrupts && vtnet_rxq_enable_intr(rxq)) { 324 vtnet_rxq_disable_intr(rxq); 325 continue; 326 } 327 break; 328 } 329 if (unlikely(token != (void *)rxq)) { 330 nm_prerr("BUG: RX token mismatch"); 331 } else { 332 /* Skip the virtio-net header. */ 333 len -= sc->vtnet_hdr_size; 334 if (unlikely(len < 0)) { 335 nm_prlim(1, "Truncated virtio-net-header, " 336 "missing %d bytes", -len); 337 len = 0; 338 } 339 ring->slot[nm_i].len = len; 340 ring->slot[nm_i].flags = 0; 341 nm_i = nm_next(nm_i, lim); 342 } 343 } 344 kring->nr_hwtail = nm_i; 345 kring->nr_kflags &= ~NKR_PENDINTR; 346 } 347 nm_prdis("[B] h %d c %d hwcur %d hwtail %d", ring->head, ring->cur, 348 kring->nr_hwcur, kring->nr_hwtail); 349 350 /* 351 * Second part: skip past packets that userspace has released. 352 */ 353 nm_i = kring->nr_hwcur; /* netmap ring index */ 354 if (nm_i != head) { 355 int howmany = head - nm_i; 356 int nm_j; 357 358 if (howmany < 0) 359 howmany += kring->nkr_num_slots; 360 nm_j = vtnet_netmap_kring_refill(kring, howmany); 361 if (nm_j < 0) 362 return nm_j; 363 kring->nr_hwcur = nm_j; 364 virtqueue_notify(vq); 365 } 366 367 nm_prdis("[C] h %d c %d t %d hwcur %d hwtail %d", ring->head, ring->cur, 368 ring->tail, kring->nr_hwcur, kring->nr_hwtail); 369 370 return 0; 371 } 372 373 374 /* Enable/disable interrupts on all virtqueues. */ 375 static void 376 vtnet_netmap_intr(struct netmap_adapter *na, int state) 377 { 378 struct vtnet_softc *sc = na->ifp->if_softc; 379 int i; 380 381 for (i = 0; i < sc->vtnet_max_vq_pairs; i++) { 382 struct vtnet_rxq *rxq = &sc->vtnet_rxqs[i]; 383 struct vtnet_txq *txq = &sc->vtnet_txqs[i]; 384 struct virtqueue *txvq = txq->vtntx_vq; 385 386 if (state) { 387 vtnet_rxq_enable_intr(rxq); 388 virtqueue_enable_intr(txvq); 389 } else { 390 vtnet_rxq_disable_intr(rxq); 391 virtqueue_disable_intr(txvq); 392 } 393 } 394 } 395 396 static int 397 vtnet_netmap_tx_slots(struct vtnet_softc *sc) 398 { 399 int div; 400 401 /* We need to prepend a virtio-net header to each netmap buffer to be 402 * transmitted, therefore calling virtqueue_enqueue() passing sglist 403 * with 2 elements. 404 * TX virtqueues use indirect descriptors if the feature was negotiated 405 * with the host, and if sc->vtnet_tx_nsegs > 1. With indirect 406 * descriptors, a single virtio descriptor is sufficient to reference 407 * each TX sglist. Without them, we need two separate virtio descriptors 408 * for each TX sglist. We therefore compute the number of netmap TX 409 * slots according to these assumptions. 410 */ 411 if ((sc->vtnet_flags & VTNET_FLAG_INDIRECT) && sc->vtnet_tx_nsegs > 1) 412 div = 1; 413 else 414 div = 2; 415 416 return virtqueue_size(sc->vtnet_txqs[0].vtntx_vq) / div; 417 } 418 419 static int 420 vtnet_netmap_rx_slots(struct vtnet_softc *sc) 421 { 422 int div; 423 424 /* We need to prepend a virtio-net header to each netmap buffer to be 425 * received, therefore calling virtqueue_enqueue() passing sglist 426 * with 2 elements. 427 * RX virtqueues use indirect descriptors if the feature was negotiated 428 * with the host, and if sc->vtnet_rx_nsegs > 1. With indirect 429 * descriptors, a single virtio descriptor is sufficient to reference 430 * each RX sglist. Without them, we need two separate virtio descriptors 431 * for each RX sglist. We therefore compute the number of netmap RX 432 * slots according to these assumptions. 433 */ 434 if ((sc->vtnet_flags & VTNET_FLAG_INDIRECT) && sc->vtnet_rx_nsegs > 1) 435 div = 1; 436 else 437 div = 2; 438 439 return virtqueue_size(sc->vtnet_rxqs[0].vtnrx_vq) / div; 440 } 441 442 static int 443 vtnet_netmap_config(struct netmap_adapter *na, struct nm_config_info *info) 444 { 445 struct vtnet_softc *sc = na->ifp->if_softc; 446 447 info->num_tx_rings = sc->vtnet_act_vq_pairs; 448 info->num_rx_rings = sc->vtnet_act_vq_pairs; 449 info->num_tx_descs = vtnet_netmap_tx_slots(sc); 450 info->num_rx_descs = vtnet_netmap_rx_slots(sc); 451 info->rx_buf_maxsize = NETMAP_BUF_SIZE(na); 452 453 return 0; 454 } 455 456 static void 457 vtnet_netmap_attach(struct vtnet_softc *sc) 458 { 459 struct netmap_adapter na; 460 461 bzero(&na, sizeof(na)); 462 463 na.ifp = sc->vtnet_ifp; 464 na.na_flags = 0; 465 na.num_tx_desc = vtnet_netmap_tx_slots(sc); 466 na.num_rx_desc = vtnet_netmap_rx_slots(sc); 467 na.num_tx_rings = na.num_rx_rings = sc->vtnet_max_vq_pairs; 468 na.rx_buf_maxsize = 0; 469 na.nm_register = vtnet_netmap_reg; 470 na.nm_txsync = vtnet_netmap_txsync; 471 na.nm_rxsync = vtnet_netmap_rxsync; 472 na.nm_intr = vtnet_netmap_intr; 473 na.nm_config = vtnet_netmap_config; 474 475 netmap_attach(&na); 476 477 nm_prinf("vtnet attached txq=%d, txd=%d rxq=%d, rxd=%d", 478 na.num_tx_rings, na.num_tx_desc, 479 na.num_tx_rings, na.num_rx_desc); 480 } 481 /* end of file */ 482