2 * Copyright (C) 2014-2018 Vincenzo Maffione, Luigi Rizzo.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
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.
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
30 #include <net/netmap.h>
31 #include <sys/selinfo.h>
33 #include <vm/pmap.h> /* vtophys ? */
34 #include <dev/netmap/netmap_kern.h>
37 * Return 1 if the queue identified by 't' and 'idx' is in netmap mode.
40 vtnet_netmap_queue_on(struct vtnet_softc *sc, enum txrx t, int idx)
42 struct netmap_adapter *na = NA(sc->vtnet_ifp);
44 if (!nm_native_on(na))
48 return !!(idx < na->num_rx_rings &&
49 na->rx_rings[idx]->nr_mode == NKR_NETMAP_ON);
51 return !!(idx < na->num_tx_rings &&
52 na->tx_rings[idx]->nr_mode == NKR_NETMAP_ON);
55 /* Register and unregister. */
57 vtnet_netmap_reg(struct netmap_adapter *na, int state)
59 struct ifnet *ifp = na->ifp;
60 struct vtnet_softc *sc = ifp->if_softc;
64 /* Drain the taskqueues to make sure that there are no worker threads
65 * accessing the virtqueues. */
66 vtnet_drain_taskqueues(sc);
70 /* We need nm_netmap_on() to return true when called by
71 * vtnet_init_locked() below. */
73 nm_set_native_flags(na);
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];
87 vtnet_txq_free_mbufs(txq);
88 VTNET_TXQ_UNLOCK(txq);
91 vtnet_rxq_free_mbufs(rxq);
92 VTNET_RXQ_UNLOCK(rxq);
94 vtnet_init_locked(sc);
95 success = (ifp->if_drv_flags & IFF_DRV_RUNNING) ? 0 : ENXIO;
98 netmap_krings_mode_commit(na, state);
100 nm_clear_native_flags(na);
101 netmap_krings_mode_commit(na, state);
104 VTNET_CORE_UNLOCK(sc);
110 /* Reconcile kernel and user view of the transmit ring. */
112 vtnet_netmap_txsync(struct netmap_kring *kring, int flags)
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;
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);
130 * First part: process new packets to send.
133 nm_i = kring->nr_hwcur;
134 if (nm_i != head) { /* we have new packets to send */
135 struct sglist *sg = txq->vtntx_sg;
137 for (; nm_i != head; nm_i = nm_next(nm_i, lim)) {
138 /* we use an empty header here */
139 struct netmap_slot *slot = &ring->slot[nm_i];
140 u_int len = slot->len;
142 void *addr = PNMB(na, slot, &paddr);
145 NM_CHECK_ADDR_LEN(na, addr, len);
147 slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
148 /* Initialize the scatterlist, expose it to the hypervisor,
149 * and kick the hypervisor (if necessary).
151 sglist_reset(sg); // cheap
152 err = sglist_append(sg, &txq->vtntx_shrhdr, sc->vtnet_hdr_size);
153 err |= sglist_append_phys(sg, paddr, len);
154 KASSERT(err == 0, ("%s: cannot append to sglist %d",
156 err = virtqueue_enqueue(vq, /*cookie=*/txq, sg,
157 /*readable=*/sg->sg_nseg,
161 nm_prerr("virtqueue_enqueue(%s) failed: %d",
167 virtqueue_notify(vq);
169 /* Update hwcur depending on where we stopped. */
170 kring->nr_hwcur = nm_i; /* note we migth break early */
173 /* Free used slots. We only consider our own used buffers, recognized
174 * by the token we passed to virtqueue_enqueue.
178 void *token = virtqueue_dequeue(vq, NULL);
181 if (unlikely(token != (void *)txq))
182 nm_prerr("BUG: TX token mismatch");
187 kring->nr_hwtail += n;
188 if (kring->nr_hwtail > lim)
189 kring->nr_hwtail -= lim + 1;
192 if (interrupts && virtqueue_nfree(vq) < 32)
193 virtqueue_postpone_intr(vq, VQ_POSTPONE_LONG);
199 * Publish (up to) num netmap receive buffers to the host,
200 * starting from the first one that the user made available
204 vtnet_netmap_kring_refill(struct netmap_kring *kring, u_int num)
206 struct netmap_adapter *na = kring->na;
207 struct ifnet *ifp = na->ifp;
208 struct netmap_ring *ring = kring->ring;
209 u_int ring_nr = kring->ring_id;
210 u_int const lim = kring->nkr_num_slots - 1;
211 u_int nm_i = kring->nr_hwcur;
213 /* device-specific */
214 struct vtnet_softc *sc = ifp->if_softc;
215 struct vtnet_rxq *rxq = &sc->vtnet_rxqs[ring_nr];
216 struct virtqueue *vq = rxq->vtnrx_vq;
218 /* use a local sglist, default might be short */
219 struct sglist_seg ss[2];
220 struct sglist sg = { ss, 0, 0, 2 };
222 for (; num > 0; nm_i = nm_next(nm_i, lim), num--) {
223 struct netmap_slot *slot = &ring->slot[nm_i];
225 void *addr = PNMB(na, slot, &paddr);
228 if (addr == NETMAP_BUF_BASE(na)) { /* bad buf */
229 if (netmap_ring_reinit(kring))
233 slot->flags &= ~NS_BUF_CHANGED;
235 err = sglist_append(&sg, &rxq->vtnrx_shrhdr, sc->vtnet_hdr_size);
236 err |= sglist_append_phys(&sg, paddr, NETMAP_BUF_SIZE(na));
237 KASSERT(err == 0, ("%s: cannot append to sglist %d",
239 /* writable for the host */
240 err = virtqueue_enqueue(vq, /*cookie=*/rxq, &sg,
241 /*readable=*/0, /*writeable=*/sg.sg_nseg);
244 nm_prerr("virtqueue_enqueue(%s) failed: %d",
254 * Publish netmap buffers on a RX virtqueue.
255 * Returns -1 if this virtqueue is not being opened in netmap mode.
256 * If the virtqueue is being opened in netmap mode, return 0 on success and
257 * a positive error code on failure.
260 vtnet_netmap_rxq_populate(struct vtnet_rxq *rxq)
262 struct netmap_adapter *na = NA(rxq->vtnrx_sc->vtnet_ifp);
263 struct netmap_kring *kring;
266 if (!nm_native_on(na) || rxq->vtnrx_id >= na->num_rx_rings)
269 kring = na->rx_rings[rxq->vtnrx_id];
270 if (!(nm_kring_pending_on(kring) ||
271 kring->nr_pending_mode == NKR_NETMAP_ON))
274 /* Expose all the RX netmap buffers we can. In case of no indirect
275 * buffers, the number of netmap slots in the RX ring matches the
276 * maximum number of 2-elements sglist that the RX virtqueue can
277 * accommodate (minus 1 to avoid netmap ring wraparound). */
278 error = vtnet_netmap_kring_refill(kring, na->num_rx_desc - 1);
279 virtqueue_notify(rxq->vtnrx_vq);
281 return error < 0 ? ENXIO : 0;
284 /* Reconcile kernel and user view of the receive ring. */
286 vtnet_netmap_rxsync(struct netmap_kring *kring, int flags)
288 struct netmap_adapter *na = kring->na;
289 struct ifnet *ifp = na->ifp;
290 struct netmap_ring *ring = kring->ring;
291 u_int ring_nr = kring->ring_id;
292 u_int nm_i; /* index into the netmap ring */
293 u_int const lim = kring->nkr_num_slots - 1;
294 u_int const head = kring->rhead;
295 int force_update = (flags & NAF_FORCE_READ) ||
296 (kring->nr_kflags & NKR_PENDINTR);
297 int interrupts = !(kring->nr_kflags & NKR_NOINTR);
299 /* device-specific */
300 struct vtnet_softc *sc = ifp->if_softc;
301 struct vtnet_rxq *rxq = &sc->vtnet_rxqs[ring_nr];
302 struct virtqueue *vq = rxq->vtnrx_vq;
305 * First part: import newly received packets.
306 * Only accept our own buffers (matching the token). We should only get
307 * matching buffers. We may need to stop early to avoid hwtail to overrun
310 if (netmap_no_pendintr || force_update) {
311 uint32_t hwtail_lim = nm_prev(kring->nr_hwcur, lim);
314 vtnet_rxq_disable_intr(rxq);
316 nm_i = kring->nr_hwtail;
317 while (nm_i != hwtail_lim) {
319 token = virtqueue_dequeue(vq, &len);
321 if (interrupts && vtnet_rxq_enable_intr(rxq)) {
322 vtnet_rxq_disable_intr(rxq);
327 if (unlikely(token != (void *)rxq)) {
328 nm_prerr("BUG: RX token mismatch");
330 /* Skip the virtio-net header. */
331 len -= sc->vtnet_hdr_size;
332 if (unlikely(len < 0)) {
333 nm_prlim(1, "Truncated virtio-net-header, "
334 "missing %d bytes", -len);
337 ring->slot[nm_i].len = len;
338 ring->slot[nm_i].flags = 0;
339 nm_i = nm_next(nm_i, lim);
342 kring->nr_hwtail = nm_i;
343 kring->nr_kflags &= ~NKR_PENDINTR;
345 nm_prdis("[B] h %d c %d hwcur %d hwtail %d", ring->head, ring->cur,
346 kring->nr_hwcur, kring->nr_hwtail);
349 * Second part: skip past packets that userspace has released.
351 nm_i = kring->nr_hwcur; /* netmap ring index */
353 int howmany = head - nm_i;
357 howmany += kring->nkr_num_slots;
358 nm_j = vtnet_netmap_kring_refill(kring, howmany);
361 kring->nr_hwcur = nm_j;
362 virtqueue_notify(vq);
365 nm_prdis("[C] h %d c %d t %d hwcur %d hwtail %d", ring->head, ring->cur,
366 ring->tail, kring->nr_hwcur, kring->nr_hwtail);
372 /* Enable/disable interrupts on all virtqueues. */
374 vtnet_netmap_intr(struct netmap_adapter *na, int state)
376 struct vtnet_softc *sc = na->ifp->if_softc;
379 for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
380 struct vtnet_rxq *rxq = &sc->vtnet_rxqs[i];
381 struct vtnet_txq *txq = &sc->vtnet_txqs[i];
382 struct virtqueue *txvq = txq->vtntx_vq;
385 vtnet_rxq_enable_intr(rxq);
386 virtqueue_enable_intr(txvq);
388 vtnet_rxq_disable_intr(rxq);
389 virtqueue_disable_intr(txvq);
395 vtnet_netmap_tx_slots(struct vtnet_softc *sc)
399 /* We need to prepend a virtio-net header to each netmap buffer to be
400 * transmitted, therefore calling virtqueue_enqueue() passing sglist
402 * TX virtqueues use indirect descriptors if the feature was negotiated
403 * with the host, and if sc->vtnet_tx_nsegs > 1. With indirect
404 * descriptors, a single virtio descriptor is sufficient to reference
405 * each TX sglist. Without them, we need two separate virtio descriptors
406 * for each TX sglist. We therefore compute the number of netmap TX
407 * slots according to these assumptions.
409 if ((sc->vtnet_flags & VTNET_FLAG_INDIRECT) && sc->vtnet_tx_nsegs > 1)
414 return virtqueue_size(sc->vtnet_txqs[0].vtntx_vq) / div;
418 vtnet_netmap_rx_slots(struct vtnet_softc *sc)
422 /* We need to prepend a virtio-net header to each netmap buffer to be
423 * received, therefore calling virtqueue_enqueue() passing sglist
425 * RX virtqueues use indirect descriptors if the feature was negotiated
426 * with the host, and if sc->vtnet_rx_nsegs > 1. With indirect
427 * descriptors, a single virtio descriptor is sufficient to reference
428 * each RX sglist. Without them, we need two separate virtio descriptors
429 * for each RX sglist. We therefore compute the number of netmap RX
430 * slots according to these assumptions.
432 if ((sc->vtnet_flags & VTNET_FLAG_INDIRECT) && sc->vtnet_rx_nsegs > 1)
437 return virtqueue_size(sc->vtnet_rxqs[0].vtnrx_vq) / div;
441 vtnet_netmap_config(struct netmap_adapter *na, struct nm_config_info *info)
443 struct vtnet_softc *sc = na->ifp->if_softc;
445 info->num_tx_rings = sc->vtnet_act_vq_pairs;
446 info->num_rx_rings = sc->vtnet_act_vq_pairs;
447 info->num_tx_descs = vtnet_netmap_tx_slots(sc);
448 info->num_rx_descs = vtnet_netmap_rx_slots(sc);
449 info->rx_buf_maxsize = NETMAP_BUF_SIZE(na);
455 vtnet_netmap_attach(struct vtnet_softc *sc)
457 struct netmap_adapter na;
459 bzero(&na, sizeof(na));
461 na.ifp = sc->vtnet_ifp;
463 na.num_tx_desc = vtnet_netmap_tx_slots(sc);
464 na.num_rx_desc = vtnet_netmap_rx_slots(sc);
465 na.num_tx_rings = na.num_rx_rings = sc->vtnet_max_vq_pairs;
466 na.rx_buf_maxsize = 0;
467 na.nm_register = vtnet_netmap_reg;
468 na.nm_txsync = vtnet_netmap_txsync;
469 na.nm_rxsync = vtnet_netmap_rxsync;
470 na.nm_intr = vtnet_netmap_intr;
471 na.nm_config = vtnet_netmap_config;
475 nm_prinf("vtnet attached txq=%d, txd=%d rxq=%d, rxd=%d",
476 na.num_tx_rings, na.num_tx_desc,
477 na.num_tx_rings, na.num_rx_desc);