if_vtnet: Add support for software LRO
This useful when running on hosts that support checksum offloading but not the GUEST_TSO (LRO) feature. Or potentially, some GRO-like support when doing forwarding. Only enable SW LRO when the host LRO is not available since both tends to be harmful, and difficult to enable/disable selectively with only a single IFCAP_LRO flag. Reviewed by: grehan (mentor) Differential Revision: https://reviews.freebsd.org/D27919
This commit is contained in:
Bryan Venteicher
parent
177761e4c4
commit
42343a6316
@ -71,6 +71,7 @@ __FBSDID("$FreeBSD$");
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#include <netinet6/ip6_var.h>
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#include <netinet/udp.h>
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#include <netinet/tcp.h>
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#include <netinet/tcp_lro.h>
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#include <machine/bus.h>
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#include <machine/resource.h>
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@ -110,6 +111,7 @@ static void vtnet_free_rxtx_queues(struct vtnet_softc *);
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static int vtnet_alloc_rx_filters(struct vtnet_softc *);
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static void vtnet_free_rx_filters(struct vtnet_softc *);
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static int vtnet_alloc_virtqueues(struct vtnet_softc *);
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static int vtnet_alloc_interface(struct vtnet_softc *);
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static int vtnet_setup_interface(struct vtnet_softc *);
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static int vtnet_ioctl_mtu(struct vtnet_softc *, int);
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static int vtnet_ioctl_ifflags(struct vtnet_softc *);
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@ -231,6 +233,7 @@ static void vtnet_setup_rxq_sysctl(struct sysctl_ctx_list *,
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static void vtnet_setup_txq_sysctl(struct sysctl_ctx_list *,
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struct sysctl_oid_list *, struct vtnet_txq *);
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static void vtnet_setup_queue_sysctl(struct vtnet_softc *);
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static void vtnet_load_tunables(struct vtnet_softc *);
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static void vtnet_setup_sysctl(struct vtnet_softc *);
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static int vtnet_rxq_enable_intr(struct vtnet_rxq *);
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@ -299,6 +302,15 @@ TUNABLE_INT("hw.vtnet.rx_process_limit", &vtnet_rx_process_limit);
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SYSCTL_INT(_hw_vtnet, OID_AUTO, rx_process_limit, CTLFLAG_RDTUN,
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&vtnet_rx_process_limit, 0, "Limits RX segments processed in a single pass");
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static int vtnet_lro_entry_count = 128;
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SYSCTL_INT(_hw_vtnet, OID_AUTO, lro_entry_count, CTLFLAG_RDTUN,
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&vtnet_lro_entry_count, 0, "Software LRO entry count");
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/* Enable sorted LRO, and the depth of the mbuf queue. */
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static int vtnet_lro_mbufq_depth = 0;
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SYSCTL_UINT(_hw_vtnet, OID_AUTO, lro_mbufq_depth, CTLFLAG_RDTUN,
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&vtnet_lro_mbufq_depth, 0, "Depth of software LRO mbuf queue");
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static uma_zone_t vtnet_tx_header_zone;
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static struct virtio_feature_desc vtnet_feature_desc[] = {
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@ -433,6 +445,13 @@ vtnet_attach(device_t dev)
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VTNET_CORE_LOCK_INIT(sc);
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callout_init_mtx(&sc->vtnet_tick_ch, VTNET_CORE_MTX(sc), 0);
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vtnet_load_tunables(sc);
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error = vtnet_alloc_interface(sc);
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if (error) {
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device_printf(dev, "cannot allocate interface\n");
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goto fail;
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}
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vtnet_setup_sysctl(sc);
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vtnet_setup_features(sc);
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@ -651,8 +670,8 @@ vtnet_negotiate_features(struct vtnet_softc *sc)
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*/
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if (!virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC)) {
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device_printf(dev,
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"LRO disabled since both mergeable buffers and "
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"indirect descriptors were not negotiated\n");
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"Host LRO disabled since both mergeable buffers "
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"and indirect descriptors were not negotiated\n");
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features &= ~VTNET_LRO_FEATURES;
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negotiated_features =
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virtio_negotiate_features(dev, features);
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@ -709,6 +728,14 @@ vtnet_setup_features(struct vtnet_softc *sc)
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else
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sc->vtnet_rx_nsegs = VTNET_RX_SEGS_HDR_SEPARATE;
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/*
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* Favor "hardware" LRO if negotiated, but support software LRO as
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* a fallback; there is usually little benefit (or worse) with both.
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*/
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if (virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO4) == 0 &&
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virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO6) == 0)
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sc->vtnet_flags |= VTNET_FLAG_SW_LRO;
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if (virtio_with_feature(dev, VIRTIO_NET_F_GSO) ||
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virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO4) ||
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virtio_with_feature(dev, VIRTIO_NET_F_HOST_TSO6))
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@ -775,6 +802,14 @@ vtnet_init_rxq(struct vtnet_softc *sc, int id)
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if (rxq->vtnrx_sg == NULL)
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return (ENOMEM);
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#if defined(INET) || defined(INET6)
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if (vtnet_software_lro(sc)) {
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if (tcp_lro_init_args(&rxq->vtnrx_lro, sc->vtnet_ifp,
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sc->vtnet_lro_entry_count, sc->vtnet_lro_mbufq_depth) != 0)
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return (ENOMEM);
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}
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#endif
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NET_TASK_INIT(&rxq->vtnrx_intrtask, 0, vtnet_rxq_tq_intr, rxq);
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rxq->vtnrx_tq = taskqueue_create(rxq->vtnrx_name, M_NOWAIT,
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taskqueue_thread_enqueue, &rxq->vtnrx_tq);
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@ -853,6 +888,10 @@ vtnet_destroy_rxq(struct vtnet_rxq *rxq)
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rxq->vtnrx_sc = NULL;
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rxq->vtnrx_id = -1;
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#if defined(INET) || defined(INET6)
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tcp_lro_free(&rxq->vtnrx_lro);
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#endif
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if (rxq->vtnrx_sg != NULL) {
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sglist_free(rxq->vtnrx_sg);
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rxq->vtnrx_sg = NULL;
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@ -991,6 +1030,25 @@ vtnet_alloc_virtqueues(struct vtnet_softc *sc)
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return (error);
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}
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static int
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vtnet_alloc_interface(struct vtnet_softc *sc)
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{
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device_t dev;
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struct ifnet *ifp;
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dev = sc->vtnet_dev;
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ifp = if_alloc(IFT_ETHER);
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if (ifp == NULL)
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return (ENOMEM);
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sc->vtnet_ifp = ifp;
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ifp->if_softc = sc;
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if_initname(ifp, device_get_name(dev), device_get_unit(dev));
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return (0);
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}
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static int
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vtnet_setup_interface(struct vtnet_softc *sc)
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{
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@ -999,15 +1057,8 @@ vtnet_setup_interface(struct vtnet_softc *sc)
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struct ifnet *ifp;
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dev = sc->vtnet_dev;
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ifp = sc->vtnet_ifp;
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ifp = sc->vtnet_ifp = if_alloc(IFT_ETHER);
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if (ifp == NULL) {
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device_printf(dev, "cannot allocate ifnet structure\n");
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return (ENOSPC);
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}
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if_initname(ifp, device_get_name(dev), device_get_unit(dev));
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ifp->if_softc = sc;
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ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST |
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IFF_KNOWSEPOCH;
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ifp->if_baudrate = IF_Gbps(10);
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@ -1072,10 +1123,8 @@ vtnet_setup_interface(struct vtnet_softc *sc)
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vtnet_fixup_needs_csum) != 0)
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sc->vtnet_flags |= VTNET_FLAG_FIXUP_NEEDS_CSUM;
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if (virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO4) ||
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virtio_with_feature(dev, VIRTIO_NET_F_GUEST_TSO6) ||
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virtio_with_feature(dev, VIRTIO_NET_F_GUEST_ECN))
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ifp->if_capabilities |= IFCAP_LRO;
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/* Support either "hardware" or software LRO. */
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ifp->if_capabilities |= IFCAP_LRO;
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}
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if (ifp->if_capabilities & (IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6)) {
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@ -1263,6 +1312,11 @@ vtnet_ioctl_ifcap(struct vtnet_softc *sc, struct ifreq *ifr)
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else
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reinit = 1;
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/* BMV: Avoid needless renegotiation for just software LRO. */
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if ((mask & (IFCAP_RXCSUM | IFCAP_RXCSUM_IPV6 | IFCAP_LRO)) ==
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IFCAP_LRO && vtnet_software_lro(sc))
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reinit = update = 0;
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if (mask & IFCAP_RXCSUM)
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ifp->if_capenable ^= IFCAP_RXCSUM;
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if (mask & IFCAP_RXCSUM_IPV6)
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@ -1869,6 +1923,23 @@ vtnet_rxq_merged_eof(struct vtnet_rxq *rxq, struct mbuf *m_head, int nbufs)
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return (1);
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}
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#if defined(INET) || defined(INET6)
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static int
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vtnet_lro_rx(struct vtnet_rxq *rxq, struct mbuf *m)
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{
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struct lro_ctrl *lro;
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lro = &rxq->vtnrx_lro;
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if (lro->lro_mbuf_max != 0) {
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tcp_lro_queue_mbuf(lro, m);
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return (0);
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}
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return (tcp_lro_rx(lro, m, 0));
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}
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#endif
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static void
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vtnet_rxq_input(struct vtnet_rxq *rxq, struct mbuf *m,
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struct virtio_net_hdr *hdr)
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@ -1906,9 +1977,14 @@ vtnet_rxq_input(struct vtnet_rxq *rxq, struct mbuf *m,
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rxq->vtnrx_stats.vrxs_ipackets++;
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rxq->vtnrx_stats.vrxs_ibytes += m->m_pkthdr.len;
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VTNET_RXQ_UNLOCK(rxq);
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#if defined(INET) || defined(INET6)
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if (vtnet_software_lro(sc) && ifp->if_capenable & IFCAP_LRO) {
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if (vtnet_lro_rx(rxq, m) == 0)
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return;
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}
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#endif
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(*ifp->if_input)(ifp, m);
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VTNET_RXQ_LOCK(rxq);
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}
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static int
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@ -2013,14 +2089,14 @@ vtnet_rxq_eof(struct vtnet_rxq *rxq)
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}
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vtnet_rxq_input(rxq, m, &lhdr);
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/* Must recheck after dropping the Rx lock. */
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if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
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break;
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}
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if (deq > 0)
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if (deq > 0) {
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#if defined(INET) || defined(INET6)
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tcp_lro_flush_all(&rxq->vtnrx_lro);
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#endif
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virtqueue_notify(vq);
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}
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return (count > 0 ? 0 : EAGAIN);
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}
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@ -3226,7 +3302,7 @@ vtnet_update_rx_offloads(struct vtnet_softc *sc)
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features &= ~VIRTIO_NET_F_GUEST_CSUM;
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}
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if (ifp->if_capabilities & IFCAP_LRO) {
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if (ifp->if_capabilities & IFCAP_LRO && !vtnet_software_lro(sc)) {
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if (ifp->if_capenable & IFCAP_LRO)
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features |= VTNET_LRO_FEATURES;
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else
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@ -4106,6 +4182,19 @@ vtnet_setup_sysctl(struct vtnet_softc *sc)
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vtnet_setup_stat_sysctl(ctx, child, sc);
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}
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static void
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vtnet_load_tunables(struct vtnet_softc *sc)
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{
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sc->vtnet_lro_entry_count = vtnet_tunable_int(sc,
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"lro_entry_count", vtnet_lro_entry_count);
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if (sc->vtnet_lro_entry_count < TCP_LRO_ENTRIES)
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sc->vtnet_lro_entry_count = TCP_LRO_ENTRIES;
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sc->vtnet_lro_mbufq_depth = vtnet_tunable_int(sc,
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"lro_mbufq_depth", vtnet_lro_mbufq_depth);
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}
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static int
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vtnet_rxq_enable_intr(struct vtnet_rxq *rxq)
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{
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@ -79,6 +79,7 @@ struct vtnet_rxq {
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struct vtnet_rxq_stats vtnrx_stats;
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struct taskqueue *vtnrx_tq;
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struct task vtnrx_intrtask;
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struct lro_ctrl vtnrx_lro;
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#ifdef DEV_NETMAP
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uint32_t vtnrx_nm_refill;
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struct virtio_net_hdr_mrg_rxbuf vtnrx_shrhdr;
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@ -155,6 +156,7 @@ struct vtnet_softc {
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#define VTNET_FLAG_EVENT_IDX 0x0800
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#define VTNET_FLAG_SUSPENDED 0x1000
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#define VTNET_FLAG_FIXUP_NEEDS_CSUM 0x2000
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#define VTNET_FLAG_SW_LRO 0x4000
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int vtnet_link_active;
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int vtnet_hdr_size;
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@ -168,6 +170,8 @@ struct vtnet_softc {
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int vtnet_act_vq_pairs;
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int vtnet_max_vq_pairs;
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int vtnet_requested_vq_pairs;
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int vtnet_lro_entry_count;
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int vtnet_lro_mbufq_depth;
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struct virtqueue *vtnet_ctrl_vq;
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struct vtnet_mac_filter *vtnet_mac_filter;
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@ -192,6 +196,12 @@ vtnet_modern(struct vtnet_softc *sc)
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return ((sc->vtnet_flags & VTNET_FLAG_MODERN) != 0);
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}
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static bool
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vtnet_software_lro(struct vtnet_softc *sc)
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{
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return ((sc->vtnet_flags & VTNET_FLAG_SW_LRO) != 0);
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}
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/*
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* Maximum number of queue pairs we will autoconfigure to.
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*/
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@ -325,8 +335,7 @@ CTASSERT(sizeof(struct vtnet_mac_filter) <= PAGE_SIZE);
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/*
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* The VIRTIO_NET_F_GUEST_TSO[46] features permit the host to send us
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* frames larger than 1514 bytes. We do not yet support software LRO
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* via tcp_lro_rx().
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* frames larger than 1514 bytes.
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*/
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#define VTNET_LRO_FEATURES (VIRTIO_NET_F_GUEST_TSO4 | \
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VIRTIO_NET_F_GUEST_TSO6 | VIRTIO_NET_F_GUEST_ECN)
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