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freebsd/sys/dev/netmap/if_vtnet_netmap.h
2014-08-17 10:25:27 +00:00

435 lines
13 KiB
C

/*
* Copyright (C) 2014 Vincenzo Maffione, Luigi Rizzo. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* $FreeBSD$
*/
#include <net/netmap.h>
#include <sys/selinfo.h>
#include <vm/vm.h>
#include <vm/pmap.h> /* vtophys ? */
#include <dev/netmap/netmap_kern.h>
#define SOFTC_T vtnet_softc
/* Free all the unused buffer in all the RX virtqueues.
* This function is called when entering and exiting netmap mode.
* - buffers queued by the virtio driver return skbuf/mbuf pointer
* and need to be freed;
* - buffers queued by netmap return the txq/rxq, and do not need work
*/
static void
vtnet_netmap_free_bufs(struct SOFTC_T* sc)
{
int i, nmb = 0, n = 0, last;
for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
struct vtnet_rxq *rxq = &sc->vtnet_rxqs[i];
struct virtqueue *vq;
struct mbuf *m;
struct vtnet_txq *txq = &sc->vtnet_txqs[i];
struct vtnet_tx_header *txhdr;
last = 0;
vq = rxq->vtnrx_vq;
while ((m = virtqueue_drain(vq, &last)) != NULL) {
n++;
if (m != (void *)rxq)
m_freem(m);
else
nmb++;
}
last = 0;
vq = txq->vtntx_vq;
while ((txhdr = virtqueue_drain(vq, &last)) != NULL) {
n++;
if (txhdr != (void *)txq) {
m_freem(txhdr->vth_mbuf);
uma_zfree(vtnet_tx_header_zone, txhdr);
} else
nmb++;
}
}
D("freed %d mbufs, %d netmap bufs on %d queues",
n - nmb, nmb, i);
}
/* Register and unregister. */
static int
vtnet_netmap_reg(struct netmap_adapter *na, int onoff)
{
struct ifnet *ifp = na->ifp;
struct SOFTC_T *sc = ifp->if_softc;
VTNET_CORE_LOCK(sc);
ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
/* enable or disable flags and callbacks in na and ifp */
if (onoff) {
nm_set_native_flags(na);
} else {
nm_clear_native_flags(na);
}
/* drain queues so netmap and native drivers
* do not interfere with each other
*/
vtnet_netmap_free_bufs(sc);
vtnet_init_locked(sc); /* also enable intr */
VTNET_CORE_UNLOCK(sc);
return (ifp->if_drv_flags & IFF_DRV_RUNNING ? 0 : 1);
}
/* Reconcile kernel and user view of the transmit ring. */
static int
vtnet_netmap_txsync(struct netmap_kring *kring, int flags)
{
struct netmap_adapter *na = kring->na;
struct ifnet *ifp = na->ifp;
struct netmap_ring *ring = kring->ring;
u_int ring_nr = kring->ring_id;
u_int nm_i; /* index into the netmap ring */
u_int nic_i; /* index into the NIC ring */
u_int n;
u_int const lim = kring->nkr_num_slots - 1;
u_int const head = kring->rhead;
/* device-specific */
struct SOFTC_T *sc = ifp->if_softc;
struct vtnet_txq *txq = &sc->vtnet_txqs[ring_nr];
struct virtqueue *vq = txq->vtntx_vq;
/*
* First part: process new packets to send.
*/
rmb();
nm_i = kring->nr_hwcur;
if (nm_i != head) { /* we have new packets to send */
struct sglist *sg = txq->vtntx_sg;
nic_i = netmap_idx_k2n(kring, nm_i);
for (n = 0; nm_i != head; n++) {
/* we use an empty header here */
static struct virtio_net_hdr_mrg_rxbuf hdr;
struct netmap_slot *slot = &ring->slot[nm_i];
u_int len = slot->len;
uint64_t paddr;
void *addr = PNMB(na, slot, &paddr);
int err;
NM_CHECK_ADDR_LEN(na, addr, len);
slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
/* Initialize the scatterlist, expose it to the hypervisor,
* and kick the hypervisor (if necessary).
*/
sglist_reset(sg); // cheap
// if vtnet_hdr_size > 0 ...
err = sglist_append(sg, &hdr, sc->vtnet_hdr_size);
// XXX later, support multi segment
err = sglist_append_phys(sg, paddr, len);
/* use na as the cookie */
err = virtqueue_enqueue(vq, txq, sg, sg->sg_nseg, 0);
if (unlikely(err < 0)) {
D("virtqueue_enqueue failed");
break;
}
nm_i = nm_next(nm_i, lim);
nic_i = nm_next(nic_i, lim);
}
/* Update hwcur depending on where we stopped. */
kring->nr_hwcur = nm_i; /* note we migth break early */
/* No more free TX slots? Ask the hypervisor for notifications,
* possibly only when a considerable amount of work has been
* done.
*/
ND(3,"sent %d packets, hwcur %d", n, nm_i);
virtqueue_disable_intr(vq);
virtqueue_notify(vq);
} else {
if (ring->head != ring->tail)
ND(5, "pure notify ? head %d tail %d nused %d %d",
ring->head, ring->tail, virtqueue_nused(vq),
(virtqueue_dump(vq), 1));
virtqueue_notify(vq);
virtqueue_enable_intr(vq); // like postpone with 0
}
/* Free used slots. We only consider our own used buffers, recognized
* by the token we passed to virtqueue_add_outbuf.
*/
n = 0;
for (;;) {
struct vtnet_tx_header *txhdr = virtqueue_dequeue(vq, NULL);
if (txhdr == NULL)
break;
if (likely(txhdr == (void *)txq)) {
n++;
if (virtqueue_nused(vq) < 32) { // XXX slow release
break;
}
} else { /* leftover from previous transmission */
m_freem(txhdr->vth_mbuf);
uma_zfree(vtnet_tx_header_zone, txhdr);
}
}
if (n) {
kring->nr_hwtail += n;
if (kring->nr_hwtail > lim)
kring->nr_hwtail -= lim + 1;
}
if (nm_i != kring->nr_hwtail /* && vtnet_txq_below_threshold(txq) == 0*/) {
ND(3, "disable intr, hwcur %d", nm_i);
virtqueue_disable_intr(vq);
} else {
ND(3, "enable intr, hwcur %d", nm_i);
virtqueue_postpone_intr(vq, VQ_POSTPONE_SHORT);
}
//out:
nm_txsync_finalize(kring);
return 0;
}
static int
vtnet_refill_rxq(struct netmap_kring *kring, u_int nm_i, u_int head)
{
struct netmap_adapter *na = kring->na;
struct ifnet *ifp = na->ifp;
struct netmap_ring *ring = kring->ring;
u_int ring_nr = kring->ring_id;
u_int const lim = kring->nkr_num_slots - 1;
u_int n;
/* device-specific */
struct SOFTC_T *sc = ifp->if_softc;
struct vtnet_rxq *rxq = &sc->vtnet_rxqs[ring_nr];
struct virtqueue *vq = rxq->vtnrx_vq;
/* use a local sglist, default might be short */
struct sglist_seg ss[2];
struct sglist sg = { ss, 0, 0, 2 };
for (n = 0; nm_i != head; n++) {
static struct virtio_net_hdr_mrg_rxbuf hdr;
struct netmap_slot *slot = &ring->slot[nm_i];
uint64_t paddr;
void *addr = PNMB(na, slot, &paddr);
int err = 0;
if (addr == NETMAP_BUF_BASE(na)) { /* bad buf */
if (netmap_ring_reinit(kring))
return -1;
}
slot->flags &= ~NS_BUF_CHANGED;
sglist_reset(&sg); // cheap
err = sglist_append(&sg, &hdr, sc->vtnet_hdr_size);
err = sglist_append_phys(&sg, paddr, NETMAP_BUF_SIZE(na));
/* writable for the host */
err = virtqueue_enqueue(vq, rxq, &sg, 0, sg.sg_nseg);
if (err < 0) {
D("virtqueue_enqueue failed");
break;
}
nm_i = nm_next(nm_i, lim);
}
return nm_i;
}
/* Reconcile kernel and user view of the receive ring. */
static int
vtnet_netmap_rxsync(struct netmap_kring *kring, int flags)
{
struct netmap_adapter *na = kring->na;
struct ifnet *ifp = na->ifp;
struct netmap_ring *ring = kring->ring;
u_int ring_nr = kring->ring_id;
u_int nm_i; /* index into the netmap ring */
// u_int nic_i; /* index into the NIC ring */
u_int n;
u_int const lim = kring->nkr_num_slots - 1;
u_int const head = nm_rxsync_prologue(kring);
int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR;
/* device-specific */
struct SOFTC_T *sc = ifp->if_softc;
struct vtnet_rxq *rxq = &sc->vtnet_rxqs[ring_nr];
struct virtqueue *vq = rxq->vtnrx_vq;
/* XXX netif_carrier_ok ? */
if (head > lim)
return netmap_ring_reinit(kring);
rmb();
/*
* First part: import newly received packets.
* Only accept our
* own buffers (matching the token). We should only get
* matching buffers, because of vtnet_netmap_free_rx_unused_bufs()
* and vtnet_netmap_init_buffers().
*/
if (netmap_no_pendintr || force_update) {
uint16_t slot_flags = kring->nkr_slot_flags;
struct netmap_adapter *token;
nm_i = kring->nr_hwtail;
n = 0;
for (;;) {
int len;
token = virtqueue_dequeue(vq, &len);
if (token == NULL)
break;
if (likely(token == (void *)rxq)) {
ring->slot[nm_i].len = len;
ring->slot[nm_i].flags = slot_flags;
nm_i = nm_next(nm_i, lim);
n++;
} else {
D("This should not happen");
}
}
kring->nr_hwtail = nm_i;
kring->nr_kflags &= ~NKR_PENDINTR;
}
ND("[B] h %d c %d hwcur %d hwtail %d",
ring->head, ring->cur, kring->nr_hwcur,
kring->nr_hwtail);
/*
* Second part: skip past packets that userspace has released.
*/
nm_i = kring->nr_hwcur; /* netmap ring index */
if (nm_i != head) {
int err = vtnet_refill_rxq(kring, nm_i, head);
if (err < 0)
return 1;
kring->nr_hwcur = err;
virtqueue_notify(vq);
/* After draining the queue may need an intr from the hypervisor */
vtnet_rxq_enable_intr(rxq);
}
/* tell userspace that there might be new packets. */
nm_rxsync_finalize(kring);
ND("[C] h %d c %d t %d hwcur %d hwtail %d",
ring->head, ring->cur, ring->tail,
kring->nr_hwcur, kring->nr_hwtail);
return 0;
}
/* Make RX virtqueues buffers pointing to netmap buffers. */
static int
vtnet_netmap_init_rx_buffers(struct SOFTC_T *sc)
{
struct ifnet *ifp = sc->vtnet_ifp;
struct netmap_adapter* na = NA(ifp);
unsigned int r;
if (!nm_native_on(na))
return 0;
for (r = 0; r < na->num_rx_rings; r++) {
struct netmap_kring *kring = &na->rx_rings[r];
struct vtnet_rxq *rxq = &sc->vtnet_rxqs[r];
struct virtqueue *vq = rxq->vtnrx_vq;
struct netmap_slot* slot;
int err = 0;
slot = netmap_reset(na, NR_RX, r, 0);
if (!slot) {
D("strange, null netmap ring %d", r);
return 0;
}
/* Add up to na>-num_rx_desc-1 buffers to this RX virtqueue.
* It's important to leave one virtqueue slot free, otherwise
* we can run into ring->cur/ring->tail wraparounds.
*/
err = vtnet_refill_rxq(kring, 0, na->num_rx_desc-1);
if (err < 0)
return 0;
virtqueue_notify(vq);
}
return 1;
}
/* Update the virtio-net device configurations. Number of queues can
* change dinamically, by 'ethtool --set-channels $IFNAME combined $N'.
* This is actually the only way virtio-net can currently enable
* the multiqueue mode.
* XXX note that we seem to lose packets if the netmap ring has more
* slots than the queue
*/
static int
vtnet_netmap_config(struct netmap_adapter *na, u_int *txr, u_int *txd,
u_int *rxr, u_int *rxd)
{
struct ifnet *ifp = na->ifp;
struct SOFTC_T *sc = ifp->if_softc;
*txr = *rxr = sc->vtnet_max_vq_pairs;
*rxd = 512; // sc->vtnet_rx_nmbufs;
*txd = *rxd; // XXX
D("vtnet config txq=%d, txd=%d rxq=%d, rxd=%d",
*txr, *txd, *rxr, *rxd);
return 0;
}
static void
vtnet_netmap_attach(struct SOFTC_T *sc)
{
struct netmap_adapter na;
bzero(&na, sizeof(na));
na.ifp = sc->vtnet_ifp;
na.num_tx_desc = 1024;// sc->vtnet_rx_nmbufs;
na.num_rx_desc = 1024; // sc->vtnet_rx_nmbufs;
na.nm_register = vtnet_netmap_reg;
na.nm_txsync = vtnet_netmap_txsync;
na.nm_rxsync = vtnet_netmap_rxsync;
na.nm_config = vtnet_netmap_config;
na.num_tx_rings = na.num_rx_rings = sc->vtnet_max_vq_pairs;
D("max rings %d", sc->vtnet_max_vq_pairs);
netmap_attach(&na);
D("virtio attached txq=%d, txd=%d rxq=%d, rxd=%d",
na.num_tx_rings, na.num_tx_desc,
na.num_tx_rings, na.num_rx_desc);
}
/* end of file */