Date: Wed, 28 Sep 2016 04:34:22 +0000 (UTC) From: Sepherosa Ziehau <sephe@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r306390 - head/sys/dev/hyperv/netvsc Message-ID: <201609280434.u8S4YMsf062895@repo.freebsd.org>
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Author: sephe Date: Wed Sep 28 04:34:21 2016 New Revision: 306390 URL: https://svnweb.freebsd.org/changeset/base/306390 Log: hyperv/hn: Suspend and resume the backend properly upon MTU change. Suspend: - Prevent the backend from being touched on TX path. - Clear the RNDIS RX filter, and wait for RX to drain. - Make sure that NVS see the chimney sending buffer and RXBUF disconnection, before unlink these buffers from the channel. Resume: - Reconfigure the RNDIS filter. - Allow TX path to work on the backend. - Kick start the TX eof task, in case the OACTIVE is set. This fixes various panics, when the interface has traffic and MTU is being changed. MFC after: 1 week Sponsored by: Microsoft Differential Revision: https://reviews.freebsd.org/D8046 Modified: head/sys/dev/hyperv/netvsc/hv_net_vsc.c head/sys/dev/hyperv/netvsc/hv_net_vsc.h head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c Modified: head/sys/dev/hyperv/netvsc/hv_net_vsc.c ============================================================================== --- head/sys/dev/hyperv/netvsc/hv_net_vsc.c Wed Sep 28 04:25:25 2016 (r306389) +++ head/sys/dev/hyperv/netvsc/hv_net_vsc.c Wed Sep 28 04:34:21 2016 (r306390) @@ -348,6 +348,16 @@ hn_nvs_disconn_rxbuf(struct hn_softc *sc return (error); } sc->hn_flags &= ~HN_FLAG_RXBUF_CONNECTED; + + /* + * Wait for the hypervisor to receive this NVS request. + */ + while (!vmbus_chan_tx_empty(sc->hn_prichan)) + pause("waittx", 1); + /* + * Linger long enough for NVS to disconnect RXBUF. + */ + pause("lingtx", (200 * hz) / 1000); } if (sc->hn_rxbuf_gpadl != 0) { @@ -389,6 +399,17 @@ hn_nvs_disconn_chim(struct hn_softc *sc) return (error); } sc->hn_flags &= ~HN_FLAG_CHIM_CONNECTED; + + /* + * Wait for the hypervisor to receive this NVS request. + */ + while (!vmbus_chan_tx_empty(sc->hn_prichan)) + pause("waittx", 1); + /* + * Linger long enough for NVS to disconnect chimney + * sending buffer. + */ + pause("lingtx", (200 * hz) / 1000); } if (sc->hn_chim_gpadl != 0) { Modified: head/sys/dev/hyperv/netvsc/hv_net_vsc.h ============================================================================== --- head/sys/dev/hyperv/netvsc/hv_net_vsc.h Wed Sep 28 04:25:25 2016 (r306389) +++ head/sys/dev/hyperv/netvsc/hv_net_vsc.h Wed Sep 28 04:34:21 2016 (r306390) @@ -178,6 +178,7 @@ struct hn_tx_ring { bus_dma_tag_t hn_tx_data_dtag; uint64_t hn_csum_assist; + int hn_suspended; int hn_gpa_cnt; struct vmbus_gpa hn_gpa[NETVSC_PACKET_MAXPAGE]; Modified: head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c ============================================================================== --- head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c Wed Sep 28 04:25:25 2016 (r306389) +++ head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c Wed Sep 28 04:34:21 2016 (r306390) @@ -348,6 +348,10 @@ static void hn_detach_allchans(struct hn static void hn_chan_callback(struct vmbus_channel *chan, void *xrxr); static void hn_set_ring_inuse(struct hn_softc *, int); static int hn_synth_attach(struct hn_softc *, int); +static bool hn_tx_ring_pending(struct hn_tx_ring *); +static void hn_suspend(struct hn_softc *); +static void hn_resume(struct hn_softc *); +static void hn_tx_ring_qflush(struct hn_tx_ring *); static void hn_nvs_handle_notify(struct hn_softc *sc, const struct vmbus_chanpkt_hdr *pkt); @@ -905,6 +909,23 @@ hn_txdesc_hold(struct hn_txdesc *txd) atomic_add_int(&txd->refs, 1); } +static bool +hn_tx_ring_pending(struct hn_tx_ring *txr) +{ + bool pending = false; + +#ifndef HN_USE_TXDESC_BUFRING + mtx_lock_spin(&txr->hn_txlist_spin); + if (txr->hn_txdesc_avail != txr->hn_txdesc_cnt) + pending = true; + mtx_unlock_spin(&txr->hn_txlist_spin); +#else + if (!buf_ring_full(txr->hn_txdesc_br)) + pending = true; +#endif + return (pending); +} + static __inline void hn_txeof(struct hn_tx_ring *txr) { @@ -1241,6 +1262,9 @@ hn_start_locked(struct hn_tx_ring *txr, KASSERT(txr == &sc->hn_tx_ring[0], ("not the first TX ring")); mtx_assert(&txr->hn_tx_lock, MA_OWNED); + if (__predict_false(txr->hn_suspended)) + return 0; + if ((ifp->if_drv_flags & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) != IFF_DRV_RUNNING) return 0; @@ -1627,6 +1651,9 @@ hn_ioctl(struct ifnet *ifp, u_long cmd, hn_set_lro_lenlim(sc, HN_LRO_LENLIM_MIN(ifp)); #endif + if (ifp->if_drv_flags & IFF_DRV_RUNNING) + hn_suspend(sc); + /* We must remove and add back the device to cause the new * MTU to take effect. This includes tearing down, but not * deleting the channel, then bringing it back up. @@ -1651,7 +1678,9 @@ hn_ioctl(struct ifnet *ifp, u_long cmd, if (sc->hn_tx_ring[0].hn_chim_size > sc->hn_chim_szmax) hn_set_chim_size(sc, sc->hn_chim_szmax); - hn_init_locked(sc); + /* All done! Resume now. */ + if (ifp->if_drv_flags & IFF_DRV_RUNNING) + hn_resume(sc); HN_UNLOCK(sc); break; @@ -2984,6 +3013,9 @@ hn_xmit(struct hn_tx_ring *txr, int len) KASSERT(hn_use_if_start == 0, ("hn_xmit is called, when if_start is enabled")); + if (__predict_false(txr->hn_suspended)) + return 0; + if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || txr->hn_oactive) return 0; @@ -3070,20 +3102,24 @@ do_sched: } static void +hn_tx_ring_qflush(struct hn_tx_ring *txr) +{ + struct mbuf *m; + + mtx_lock(&txr->hn_tx_lock); + while ((m = buf_ring_dequeue_sc(txr->hn_mbuf_br)) != NULL) + m_freem(m); + mtx_unlock(&txr->hn_tx_lock); +} + +static void hn_xmit_qflush(struct ifnet *ifp) { struct hn_softc *sc = ifp->if_softc; int i; - for (i = 0; i < sc->hn_tx_ring_inuse; ++i) { - struct hn_tx_ring *txr = &sc->hn_tx_ring[i]; - struct mbuf *m; - - mtx_lock(&txr->hn_tx_lock); - while ((m = buf_ring_dequeue_sc(txr->hn_mbuf_br)) != NULL) - m_freem(m); - mtx_unlock(&txr->hn_tx_lock); - } + for (i = 0; i < sc->hn_tx_ring_inuse; ++i) + hn_tx_ring_qflush(&sc->hn_tx_ring[i]); if_qflush(ifp); } @@ -3503,6 +3539,111 @@ hn_set_ring_inuse(struct hn_softc *sc, i } static void +hn_rx_drain(struct vmbus_channel *chan) +{ + + while (!vmbus_chan_rx_empty(chan) || !vmbus_chan_tx_empty(chan)) + pause("waitch", 1); + vmbus_chan_intr_drain(chan); +} + +static void +hn_suspend(struct hn_softc *sc) +{ + struct vmbus_channel **subch = NULL; + int i, nsubch; + + HN_LOCK_ASSERT(sc); + + /* + * Suspend TX. + */ + for (i = 0; i < sc->hn_tx_ring_inuse; ++i) { + struct hn_tx_ring *txr = &sc->hn_tx_ring[i]; + + mtx_lock(&txr->hn_tx_lock); + txr->hn_suspended = 1; + mtx_unlock(&txr->hn_tx_lock); + /* No one is able send more packets now. */ + + /* Wait for all pending sends to finish. */ + while (hn_tx_ring_pending(txr)) + pause("hnwtx", 1 /* 1 tick */); + } + + /* + * Disable RX. + */ + hv_rf_on_close(sc); + + /* Give RNDIS enough time to flush all pending data packets. */ + pause("waitrx", (200 * hz) / 1000); + + nsubch = sc->hn_rx_ring_inuse - 1; + if (nsubch > 0) + subch = vmbus_subchan_get(sc->hn_prichan, nsubch); + + /* + * Drain RX/TX bufrings and interrupts. + */ + if (subch != NULL) { + for (i = 0; i < nsubch; ++i) + hn_rx_drain(subch[i]); + } + hn_rx_drain(sc->hn_prichan); + + if (subch != NULL) + vmbus_subchan_rel(subch, nsubch); +} + +static void +hn_resume(struct hn_softc *sc) +{ + struct hn_tx_ring *txr; + int i; + + HN_LOCK_ASSERT(sc); + + /* + * Re-enable RX. + */ + hv_rf_on_open(sc); + + /* + * Make sure to clear suspend status on "all" TX rings, + * since hn_tx_ring_inuse can be changed after hn_suspend(). + */ + for (i = 0; i < sc->hn_tx_ring_cnt; ++i) { + txr = &sc->hn_tx_ring[i]; + + mtx_lock(&txr->hn_tx_lock); + txr->hn_suspended = 0; + mtx_unlock(&txr->hn_tx_lock); + } + + if (!hn_use_if_start) { + /* + * Flush unused drbrs, since hn_tx_ring_inuse may be + * reduced. + */ + for (i = sc->hn_tx_ring_inuse; i < sc->hn_tx_ring_cnt; ++i) + hn_tx_ring_qflush(&sc->hn_tx_ring[i]); + } + + /* + * Kick start TX. + */ + for (i = 0; i < sc->hn_tx_ring_inuse; ++i) { + txr = &sc->hn_tx_ring[i]; + /* + * Use txeof task, so that any pending oactive can be + * cleared properly. + */ + taskqueue_enqueue(txr->hn_tx_taskq, &txr->hn_txeof_task); + } +} + +static void hn_nvs_handle_notify(struct hn_softc *sc, const struct vmbus_chanpkt_hdr *pkt) { const struct hn_nvs_hdr *hdr;
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