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vtnet: fix netmap support

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netmap(4) support for vtnet(4) was incomplete and had multiple bugs.
This commit fixes those bugs to bring netmap on vtnet in a functional state.

Changelist:
  - handle errors returned by virtqueue_enqueue() properly (they were
    previously ignored)
  - make sure netmap XOR rest of the kernel access each virtqueue.
  - compute the number of netmap slots for TX and RX separately, according to
    whether indirect descriptors are used or not for a given virtqueue.
  - make sure sglist are freed according to their type (mbufs or netmap
    buffers)
  - add support for mulitiqueue and netmap host (aka sw) rings.
  - intercept VQ interrupts directly instead of intercepting them in txq_eof
    and rxq_eof. This simplifies the code and makes it easier to make sure
    taskqueues are not running for a VQ while it is in netmap mode.
  - implement vntet_netmap_config() to cope with changes in the number of queues.

Reviewed by:	bryanv
Approved by:	gnn (mentor)
MFC after:	3 days
Sponsored by:	Sunny Valley Networks
Differential Revision:	https://reviews.freebsd.org/D17916
This commit is contained in:
Vincenzo Maffione 2018-11-14 15:39:48 +00:00
parent 8d4ceb9cc4
commit 2e42b74a6f
3 changed files with 362 additions and 246 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

532
sys/dev/netmap/if_vtnet_netmap.h
View File

@ -1,5 +1,5 @@
/*
* Copyright (C) 2014 Vincenzo Maffione, Luigi Rizzo. All rights reserved.
* Copyright (C) 2014-2018 Vincenzo Maffione, Luigi Rizzo.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@ -33,74 +33,148 @@
#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
/*
* Return 1 if the queue identified by 't' and 'idx' is in netmap mode.
*/
static void
vtnet_netmap_free_bufs(struct SOFTC_T* sc)
static int
vtnet_netmap_queue_on(struct vtnet_softc *sc, enum txrx t, int idx)
{
int i, nmb = 0, n = 0, last;
struct netmap_adapter *na = NA(sc->vtnet_ifp);
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;
if (!nm_native_on(na))
return 0;
last = 0;
vq = rxq->vtnrx_vq;
while ((m = virtqueue_drain(vq, &last)) != NULL) {
n++;
if (m != (void *)rxq)
if (t == NR_RX)
return !!(idx < na->num_rx_rings &&
na->rx_rings[idx]->nr_mode == NKR_NETMAP_ON);
return !!(idx < na->num_tx_rings &&
na->tx_rings[idx]->nr_mode == NKR_NETMAP_ON);
}
static void
vtnet_free_used(struct virtqueue *vq, int netmap_bufs, enum txrx t, int idx)
{
void *cookie;
int deq = 0;
while ((cookie = virtqueue_dequeue(vq, NULL)) != NULL) {
if (netmap_bufs) {
/* These are netmap buffers: there is nothing to do. */
} else {
/* These are mbufs that we need to free. */
struct mbuf *m;
if (t == NR_TX) {
struct vtnet_tx_header *txhdr = cookie;
m = txhdr->vth_mbuf;
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++;
} else {
m = cookie;
m_freem(m);
}
}
deq++;
}
D("freed %d mbufs, %d netmap bufs on %d queues",
n - nmb, nmb, i);
if (deq)
nm_prinf("%d sgs dequeued from %s-%d (netmap=%d)\n",
deq, nm_txrx2str(t), idx, netmap_bufs);
}
/* Register and unregister. */
static int
vtnet_netmap_reg(struct netmap_adapter *na, int onoff)
vtnet_netmap_reg(struct netmap_adapter *na, int state)
{
struct ifnet *ifp = na->ifp;
struct SOFTC_T *sc = ifp->if_softc;
struct ifnet *ifp = na->ifp;
struct vtnet_softc *sc = ifp->if_softc;
int success;
enum txrx t;
int i;
/* Drain the taskqueues to make sure that there are no worker threads
* accessing the virtqueues. */
vtnet_drain_taskqueues(sc);
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) {
/* We need nm_netmap_on() to return true when called by
* vtnet_init_locked() below. */
if (state)
nm_set_native_flags(na);
/* We need to trigger a device reset in order to unexpose guest buffers
* published to the host. */
ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
/* Get pending used buffers. The way they are freed depends on whether
* they are netmap buffer or they are mbufs. We can tell apart the two
* cases by looking at kring->nr_mode, before this is possibly updated
* in the loop below. */
for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
struct vtnet_txq *txq = &sc->vtnet_txqs[i];
struct vtnet_rxq *rxq = &sc->vtnet_rxqs[i];
struct netmap_kring *kring;
VTNET_TXQ_LOCK(txq);
kring = NMR(na, NR_TX)[i];
vtnet_free_used(txq->vtntx_vq,
kring->nr_mode == NKR_NETMAP_ON, NR_TX, i);
VTNET_TXQ_UNLOCK(txq);
VTNET_RXQ_LOCK(rxq);
kring = NMR(na, NR_RX)[i];
vtnet_free_used(rxq->vtnrx_vq,
kring->nr_mode == NKR_NETMAP_ON, NR_RX, i);
VTNET_RXQ_UNLOCK(rxq);
}
vtnet_init_locked(sc);
success = (ifp->if_drv_flags & IFF_DRV_RUNNING) ? 0 : ENXIO;
if (state) {
for_rx_tx(t) {
/* Hardware rings. */
for (i = 0; i < nma_get_nrings(na, t); i++) {
struct netmap_kring *kring = NMR(na, t)[i];
if (nm_kring_pending_on(kring))
kring->nr_mode = NKR_NETMAP_ON;
}
/* Host rings. */
for (i = 0; i < nma_get_host_nrings(na, t); i++) {
struct netmap_kring *kring =
NMR(na, t)[nma_get_nrings(na, t) + i];
if (nm_kring_pending_on(kring))
kring->nr_mode = NKR_NETMAP_ON;
}
}
} else {
nm_clear_native_flags(na);
for_rx_tx(t) {
/* Hardware rings. */
for (i = 0; i < nma_get_nrings(na, t); i++) {
struct netmap_kring *kring = NMR(na, t)[i];
if (nm_kring_pending_off(kring))
kring->nr_mode = NKR_NETMAP_OFF;
}
/* Host rings. */
for (i = 0; i < nma_get_host_nrings(na, t); i++) {
struct netmap_kring *kring =
NMR(na, t)[nma_get_nrings(na, t) + i];
if (nm_kring_pending_off(kring))
kring->nr_mode = NKR_NETMAP_OFF;
}
}
}
/* 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);
VTNET_CORE_UNLOCK(sc);
return success;
}
@ -109,20 +183,19 @@ static int
vtnet_netmap_txsync(struct netmap_kring *kring, int flags)
{
struct netmap_adapter *na = kring->na;
struct ifnet *ifp = na->ifp;
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_softc *sc = ifp->if_softc;
struct vtnet_txq *txq = &sc->vtnet_txqs[ring_nr];
struct virtqueue *vq = txq->vtntx_vq;
int interrupts = !(kring->nr_kflags & NKR_NOINTR);
u_int n;
/*
* First part: process new packets to send.
@ -133,15 +206,13 @@ vtnet_netmap_txsync(struct netmap_kring *kring, int flags)
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++) {
for (; nm_i != head; nm_i = nm_next(nm_i, lim)) {
/* 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;
int err;
NM_CHECK_ADDR_LEN(na, addr, len);
@ -150,88 +221,63 @@ vtnet_netmap_txsync(struct netmap_kring *kring, int flags)
* 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);
if (interrupts) {
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
err = sglist_append(sg, &txq->vtntx_shrhdr, sc->vtnet_hdr_size);
err |= sglist_append_phys(sg, paddr, len);
KASSERT(err == 0, ("%s: cannot append to sglist %d",
__func__, err));
err = virtqueue_enqueue(vq, /*cookie=*/txq, sg,
/*readable=*/sg->sg_nseg,
/*writeable=*/0);
if (unlikely(err)) {
if (err != ENOSPC)
nm_prerr("virtqueue_enqueue(%s) failed: %d\n",
kring->name, err);
break;
}
} else { /* leftover from previous transmission */
m_freem(txhdr->vth_mbuf);
uma_zfree(vtnet_tx_header_zone, txhdr);
}
}
if (n) {
virtqueue_notify(vq);
/* Update hwcur depending on where we stopped. */
kring->nr_hwcur = nm_i; /* note we migth break early */
}
/* Free used slots. We only consider our own used buffers, recognized
* by the token we passed to virtqueue_enqueue.
*/
n = 0;
for (;;) {
void *token = virtqueue_dequeue(vq, NULL);
if (token == NULL)
break;
if (unlikely(token != (void *)txq))
nm_prerr("BUG: TX token mismatch\n");
else
n++;
}
if (n > 0) {
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 if (interrupts) {
ND(3, "enable intr, hwcur %d", nm_i);
virtqueue_postpone_intr(vq, VQ_POSTPONE_SHORT);
}
return 0;
if (interrupts && virtqueue_nfree(vq) < 32)
virtqueue_postpone_intr(vq, VQ_POSTPONE_LONG);
return 0;
}
static int
vtnet_refill_rxq(struct netmap_kring *kring, u_int nm_i, u_int head)
vtnet_netmap_kring_refill(struct netmap_kring *kring, u_int nm_i, u_int head)
{
struct netmap_adapter *na = kring->na;
struct ifnet *ifp = na->ifp;
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_softc *sc = ifp->if_softc;
struct vtnet_rxq *rxq = &sc->vtnet_rxqs[ring_nr];
struct virtqueue *vq = rxq->vtnrx_vq;
@ -239,12 +285,11 @@ vtnet_refill_rxq(struct netmap_kring *kring, u_int nm_i, u_int head)
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;
for (; nm_i != head; nm_i = nm_next(nm_i, lim)) {
struct netmap_slot *slot = &ring->slot[nm_i];
uint64_t paddr;
void *addr = PNMB(na, slot, &paddr);
int err = 0;
int err;
if (addr == NETMAP_BUF_BASE(na)) { /* bad buf */
if (netmap_ring_reinit(kring))
@ -252,99 +297,134 @@ vtnet_refill_rxq(struct netmap_kring *kring, u_int nm_i, u_int head)
}
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));
sglist_reset(&sg);
err = sglist_append(&sg, &rxq->vtnrx_shrhdr, sc->vtnet_hdr_size);
err |= sglist_append_phys(&sg, paddr, NETMAP_BUF_SIZE(na));
KASSERT(err == 0, ("%s: cannot append to sglist %d",
__func__, err));
/* writable for the host */
err = virtqueue_enqueue(vq, rxq, &sg, 0, sg.sg_nseg);
if (err < 0) {
D("virtqueue_enqueue failed");
err = virtqueue_enqueue(vq, /*cookie=*/rxq, &sg,
/*readable=*/0, /*writeable=*/sg.sg_nseg);
if (unlikely(err)) {
if (err != ENOSPC)
nm_prerr("virtqueue_enqueue(%s) failed: %d\n",
kring->name, err);
break;
}
nm_i = nm_next(nm_i, lim);
}
return nm_i;
}
/*
* Publish netmap buffers on a RX virtqueue.
* Returns -1 if this virtqueue is not being opened in netmap mode.
* If the virtqueue is being opened in netmap mode, return 0 on success and
* a positive error code on failure.
*/
static int
vtnet_netmap_rxq_populate(struct vtnet_rxq *rxq)
{
struct netmap_adapter *na = NA(rxq->vtnrx_sc->vtnet_ifp);
struct netmap_kring *kring;
int error;
if (!nm_native_on(na) || rxq->vtnrx_id >= na->num_rx_rings)
return -1;
kring = na->rx_rings[rxq->vtnrx_id];
if (!(nm_kring_pending_on(kring) ||
kring->nr_pending_mode == NKR_NETMAP_ON))
return -1;
/* Expose all the RX netmap buffers. Note that the number of
* netmap slots in the RX ring matches the maximum number of
* 2-elements sglist that the RX virtqueue can accommodate. */
error = vtnet_netmap_kring_refill(kring, 0, na->num_rx_desc);
virtqueue_notify(rxq->vtnrx_vq);
return error < 0 ? ENXIO : 0;
}
/* 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 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;
int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR;
int force_update = (flags & NAF_FORCE_READ) ||
(kring->nr_kflags & NKR_PENDINTR);
int interrupts = !(kring->nr_kflags & NKR_NOINTR);
/* device-specific */
struct SOFTC_T *sc = ifp->if_softc;
struct vtnet_softc *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().
* Only accept our own buffers (matching the token). We should only get
* matching buffers. We may need to stop early to avoid hwtail to overrun
* hwcur.
*/
if (netmap_no_pendintr || force_update) {
struct netmap_adapter *token;
uint32_t hwtail_lim = nm_prev(kring->nr_hwcur, lim);
void *token;
nm_i = kring->nr_hwtail;
n = 0;
for (;;) {
vtnet_rxq_disable_intr(rxq);
nm_i = kring->nr_hwtail;
while (nm_i != hwtail_lim) {
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 = 0;
nm_i = nm_next(nm_i, lim);
n++;
} else {
D("This should not happen");
}
token = virtqueue_dequeue(vq, &len);
if (token == NULL) {
if (interrupts && vtnet_rxq_enable_intr(rxq)) {
vtnet_rxq_disable_intr(rxq);
continue;
}
break;
}
if (unlikely(token != (void *)rxq)) {
nm_prerr("BUG: RX token mismatch\n");
} else {
/* Skip the virtio-net header. */
len -= sc->vtnet_hdr_size;
if (unlikely(len < 0)) {
RD(1, "Truncated virtio-net-header, "
"missing %d bytes", -len);
len = 0;
}
ring->slot[nm_i].len = len;
ring->slot[nm_i].flags = 0;
nm_i = nm_next(nm_i, lim);
}
}
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);
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;
int nm_j = vtnet_netmap_kring_refill(kring, nm_i, head);
if (nm_j < 0)
return nm_j;
kring->nr_hwcur = nm_j;
virtqueue_notify(vq);
/* After draining the queue may need an intr from the hypervisor */
if (interrupts) {
vtnet_rxq_enable_intr(rxq);
}
}
ND("[C] h %d c %d t %d hwcur %d hwtail %d",
ring->head, ring->cur, ring->tail,
kring->nr_hwcur, kring->nr_hwtail);
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;
}
@ -352,9 +432,9 @@ vtnet_netmap_rxsync(struct netmap_kring *kring, int flags)
/* Enable/disable interrupts on all virtqueues. */
static void
vtnet_netmap_intr(struct netmap_adapter *na, int onoff)
vtnet_netmap_intr(struct netmap_adapter *na, int state)
{
struct SOFTC_T *sc = na->ifp->if_softc;
struct vtnet_softc *sc = na->ifp->if_softc;
int i;
for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
@ -362,7 +442,7 @@ vtnet_netmap_intr(struct netmap_adapter *na, int onoff)
struct vtnet_txq *txq = &sc->vtnet_txqs[i];
struct virtqueue *txvq = txq->vtntx_vq;
if (onoff) {
if (state) {
vtnet_rxq_enable_intr(rxq);
virtqueue_enable_intr(txvq);
} else {
@ -372,60 +452,88 @@ vtnet_netmap_intr(struct netmap_adapter *na, int onoff)
}
}
/* Make RX virtqueues buffers pointing to netmap buffers. */
static int
vtnet_netmap_init_rx_buffers(struct SOFTC_T *sc)
vtnet_netmap_tx_slots(struct vtnet_softc *sc)
{
struct ifnet *ifp = sc->vtnet_ifp;
struct netmap_adapter* na = NA(ifp);
unsigned int r;
int div;
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;
/* We need to prepend a virtio-net header to each netmap buffer to be
* transmitted, therefore calling virtqueue_enqueue() passing sglist
* with 2 elements.
* TX virtqueues use indirect descriptors if the feature was negotiated
* with the host, and if sc->vtnet_tx_nsegs > 1. With indirect
* descriptors, a single virtio descriptor is sufficient to reference
* each TX sglist. Without them, we need two separate virtio descriptors
* for each TX sglist. We therefore compute the number of netmap TX
* slots according to these assumptions.
*/
if ((sc->vtnet_flags & VTNET_FLAG_INDIRECT) && sc->vtnet_tx_nsegs > 1)
div = 1;
else
div = 2;
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 virtqueue_size(sc->vtnet_txqs[0].vtntx_vq) / div;
}
return 1;
static int
vtnet_netmap_rx_slots(struct vtnet_softc *sc)
{
int div;
/* We need to prepend a virtio-net header to each netmap buffer to be
* received, therefore calling virtqueue_enqueue() passing sglist
* with 2 elements.
* RX virtqueues use indirect descriptors if the feature was negotiated
* with the host, and if sc->vtnet_rx_nsegs > 1. With indirect
* descriptors, a single virtio descriptor is sufficient to reference
* each RX sglist. Without them, we need two separate virtio descriptors
* for each RX sglist. We therefore compute the number of netmap RX
* slots according to these assumptions.
*/
if ((sc->vtnet_flags & VTNET_FLAG_INDIRECT) && sc->vtnet_rx_nsegs > 1)
div = 1;
else
div = 2;
return virtqueue_size(sc->vtnet_rxqs[0].vtnrx_vq) / div;
}
static int
vtnet_netmap_config(struct netmap_adapter *na, struct nm_config_info *info)
{
struct vtnet_softc *sc = na->ifp->if_softc;
info->num_tx_rings = sc->vtnet_act_vq_pairs;
info->num_rx_rings = sc->vtnet_act_vq_pairs;
info->num_tx_descs = vtnet_netmap_tx_slots(sc);
info->num_rx_descs = vtnet_netmap_rx_slots(sc);
info->rx_buf_maxsize = NETMAP_BUF_SIZE(na);
return 0;
}
static void
vtnet_netmap_attach(struct SOFTC_T *sc)
vtnet_netmap_attach(struct vtnet_softc *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.na_flags = 0;
na.num_tx_desc = vtnet_netmap_tx_slots(sc);
na.num_rx_desc = vtnet_netmap_rx_slots(sc);
na.num_tx_rings = na.num_rx_rings = sc->vtnet_max_vq_pairs;
na.rx_buf_maxsize = 0;
na.nm_register = vtnet_netmap_reg;
na.nm_txsync = vtnet_netmap_txsync;
na.nm_rxsync = vtnet_netmap_rxsync;
na.nm_intr = vtnet_netmap_intr;
na.num_tx_rings = na.num_rx_rings = sc->vtnet_max_vq_pairs;
D("max rings %d", sc->vtnet_max_vq_pairs);
na.nm_config = vtnet_netmap_config;
netmap_attach(&na);
D("virtio attached txq=%d, txd=%d rxq=%d, rxd=%d",
nm_prinf("vtnet attached txq=%d, txd=%d rxq=%d, rxd=%d\n",
na.num_tx_rings, na.num_tx_desc,
na.num_tx_rings, na.num_rx_desc);
}

70
sys/dev/virtio/network/if_vtnet.c
View File

@ -1192,6 +1192,12 @@ vtnet_rxq_populate(struct vtnet_rxq *rxq)
struct virtqueue *vq;
int nbufs, error;
#ifdef DEV_NETMAP
error = vtnet_netmap_rxq_populate(rxq);
if (error >= 0)
return (error);
#endif /* DEV_NETMAP */
vq = rxq->vtnrx_vq;
error = ENOSPC;
@ -1221,12 +1227,20 @@ vtnet_rxq_free_mbufs(struct vtnet_rxq *rxq)
struct virtqueue *vq;
struct mbuf *m;
int last;
#ifdef DEV_NETMAP
int netmap_bufs = vtnet_netmap_queue_on(rxq->vtnrx_sc, NR_RX,
rxq->vtnrx_id);
#else /* !DEV_NETMAP */
int netmap_bufs = 0;
#endif /* !DEV_NETMAP */
vq = rxq->vtnrx_vq;
last = 0;
while ((m = virtqueue_drain(vq, &last)) != NULL)
m_freem(m);
while ((m = virtqueue_drain(vq, &last)) != NULL) {
if (!netmap_bufs)
m_freem(m);
}
KASSERT(virtqueue_empty(vq),
("%s: mbufs remaining in rx queue %p", __func__, rxq));
@ -1772,12 +1786,6 @@ vtnet_rxq_eof(struct vtnet_rxq *rxq)
VTNET_RXQ_LOCK_ASSERT(rxq);
#ifdef DEV_NETMAP
if (netmap_rx_irq(ifp, 0, &deq)) {
return (FALSE);
}
#endif /* DEV_NETMAP */
while (count-- > 0) {
m = virtqueue_dequeue(vq, &len);
if (m == NULL)
@ -1871,6 +1879,11 @@ vtnet_rx_vq_intr(void *xrxq)
return;
}
#ifdef DEV_NETMAP
if (netmap_rx_irq(ifp, rxq->vtnrx_id, &more) != NM_IRQ_PASS)
return;
#endif /* DEV_NETMAP */
VTNET_RXQ_LOCK(rxq);
again:
@ -1971,13 +1984,21 @@ vtnet_txq_free_mbufs(struct vtnet_txq *txq)
struct virtqueue *vq;
struct vtnet_tx_header *txhdr;
int last;
#ifdef DEV_NETMAP
int netmap_bufs = vtnet_netmap_queue_on(txq->vtntx_sc, NR_TX,
txq->vtntx_id);
#else /* !DEV_NETMAP */
int netmap_bufs = 0;
#endif /* !DEV_NETMAP */
vq = txq->vtntx_vq;
last = 0;
while ((txhdr = virtqueue_drain(vq, &last)) != NULL) {
m_freem(txhdr->vth_mbuf);
uma_zfree(vtnet_tx_header_zone, txhdr);
if (!netmap_bufs) {
m_freem(txhdr->vth_mbuf);
uma_zfree(vtnet_tx_header_zone, txhdr);
}
}
KASSERT(virtqueue_empty(vq),
@ -2465,13 +2486,6 @@ vtnet_txq_eof(struct vtnet_txq *txq)
deq = 0;
VTNET_TXQ_LOCK_ASSERT(txq);
#ifdef DEV_NETMAP
if (netmap_tx_irq(txq->vtntx_sc->vtnet_ifp, txq->vtntx_id)) {
virtqueue_disable_intr(vq); // XXX luigi
return 0; // XXX or 1 ?
}
#endif /* DEV_NETMAP */
while ((txhdr = virtqueue_dequeue(vq, NULL)) != NULL) {
m = txhdr->vth_mbuf;
deq++;
@ -2513,6 +2527,11 @@ vtnet_tx_vq_intr(void *xtxq)
return;
}
#ifdef DEV_NETMAP
if (netmap_tx_irq(ifp, txq->vtntx_id) != NM_IRQ_PASS)
return;
#endif /* DEV_NETMAP */
VTNET_TXQ_LOCK(txq);
if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
@ -2769,11 +2788,6 @@ vtnet_drain_rxtx_queues(struct vtnet_softc *sc)
struct vtnet_txq *txq;
int i;
#ifdef DEV_NETMAP
if (nm_native_on(NA(sc->vtnet_ifp)))
return;
#endif /* DEV_NETMAP */
for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
rxq = &sc->vtnet_rxqs[i];
vtnet_rxq_free_mbufs(rxq);
@ -2938,11 +2952,6 @@ vtnet_init_rx_queues(struct vtnet_softc *sc)
("%s: too many rx mbufs %d for %d segments", __func__,
sc->vtnet_rx_nmbufs, sc->vtnet_rx_nsegs));
#ifdef DEV_NETMAP
if (vtnet_netmap_init_rx_buffers(sc))
return 0;
#endif /* DEV_NETMAP */
for (i = 0; i < sc->vtnet_act_vq_pairs; i++) {
rxq = &sc->vtnet_rxqs[i];
@ -3093,13 +3102,6 @@ vtnet_init(void *xsc)
sc = xsc;
#ifdef DEV_NETMAP
if (!NA(sc->vtnet_ifp)) {
D("try to attach again");
vtnet_netmap_attach(sc);
}
#endif /* DEV_NETMAP */
VTNET_CORE_LOCK(sc);
vtnet_init_locked(sc);
VTNET_CORE_UNLOCK(sc);

6
sys/dev/virtio/network/if_vtnetvar.h
View File

@ -79,6 +79,9 @@ struct vtnet_rxq {
struct vtnet_rxq_stats vtnrx_stats;
struct taskqueue *vtnrx_tq;
struct task vtnrx_intrtask;
#ifdef DEV_NETMAP
struct virtio_net_hdr_mrg_rxbuf vtnrx_shrhdr;
#endif /* DEV_NETMAP */
char vtnrx_name[16];
} __aligned(CACHE_LINE_SIZE);
@ -114,6 +117,9 @@ struct vtnet_txq {
#ifndef VTNET_LEGACY_TX
struct task vtntx_defrtask;
#endif
#ifdef DEV_NETMAP
struct virtio_net_hdr_mrg_rxbuf vtntx_shrhdr;
#endif /* DEV_NETMAP */
char vtntx_name[16];
} __aligned(CACHE_LINE_SIZE);