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hyperv/hn: Fix primary channel revocation

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Since hypervisor will not drain the TX bufring, once the channels are
revoked:
- Setup vmbus orphan handler properly.
- Make sure that suspension will not wait the TX bufring draining
  forever.
- GC the pending TX descs on detach path, before freeing the busdma
  stuffs.

MFC after:	1 week
Sponsored by:	Microsoft
Differential Revision:	https://reviews.freebsd.org/D8559
This commit is contained in:
Sepherosa Ziehau 2016-11-24 07:35:16 +00:00
parent 24de97b49a
commit 25641fc705
2 changed files with 118 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
sys/dev/hyperv/netvsc/hn_nvs.c
View File

@ -336,8 +336,13 @@ hn_nvs_disconn_rxbuf(struct hn_softc *sc)
/*
* Wait for the hypervisor to receive this NVS request.
*
* NOTE:
* The TX bufring will not be drained by the hypervisor,
* if the primary channel is revoked.
*/
while (!vmbus_chan_tx_empty(sc->hn_prichan))
while (!vmbus_chan_tx_empty(sc->hn_prichan) &&
!vmbus_chan_is_revoked(sc->hn_prichan))
pause("waittx", 1);
/*
* Linger long enough for NVS to disconnect RXBUF.
@ -387,8 +392,13 @@ hn_nvs_disconn_chim(struct hn_softc *sc)
/*
* Wait for the hypervisor to receive this NVS request.
*
* NOTE:
* The TX bufring will not be drained by the hypervisor,
* if the primary channel is revoked.
*/
while (!vmbus_chan_tx_empty(sc->hn_prichan))
while (!vmbus_chan_tx_empty(sc->hn_prichan) &&
!vmbus_chan_is_revoked(sc->hn_prichan))
pause("waittx", 1);
/*
* Linger long enough for NVS to disconnect chimney

132
sys/dev/hyperv/netvsc/if_hn.c
View File

@ -303,7 +303,8 @@ static void hn_resume(struct hn_softc *);
static void hn_resume_data(struct hn_softc *);
static void hn_resume_mgmt(struct hn_softc *);
static void hn_suspend_mgmt_taskfunc(void *, int);
static void hn_chan_drain(struct vmbus_channel *);
static void hn_chan_drain(struct hn_softc *,
struct vmbus_channel *);
static void hn_update_link_status(struct hn_softc *);
static void hn_change_network(struct hn_softc *);
@ -327,6 +328,8 @@ static int hn_create_tx_data(struct hn_softc *, int);
static void hn_fixup_tx_data(struct hn_softc *);
static void hn_destroy_tx_data(struct hn_softc *);
static void hn_txdesc_dmamap_destroy(struct hn_txdesc *);
static void hn_txdesc_gc(struct hn_tx_ring *,
struct hn_txdesc *);
static int hn_encap(struct ifnet *, struct hn_tx_ring *,
struct hn_txdesc *, struct mbuf **);
static int hn_txpkt(struct ifnet *, struct hn_tx_ring *,
@ -994,8 +997,25 @@ hn_attach(device_t dev)
*/
sc->hn_xact = vmbus_xact_ctx_create(bus_get_dma_tag(dev),
HN_XACT_REQ_SIZE, HN_XACT_RESP_SIZE, 0);
if (sc->hn_xact == NULL)
if (sc->hn_xact == NULL) {
error = ENXIO;
goto failed;
}
/*
* Install orphan handler for the revocation of this device's
* primary channel.
*
* NOTE:
* The processing order is critical here:
* Install the orphan handler, _before_ testing whether this
* device's primary channel has been revoked or not.
*/
vmbus_chan_set_orphan(sc->hn_prichan, sc->hn_xact);
if (vmbus_chan_is_revoked(sc->hn_prichan)) {
error = ENXIO;
goto failed;
}
/*
* Attach the synthetic parts, i.e. NVS and RNDIS.
@ -1170,6 +1190,14 @@ hn_detach(device_t dev)
struct hn_softc *sc = device_get_softc(dev);
struct ifnet *ifp = sc->hn_ifp;
if (sc->hn_xact != NULL && vmbus_chan_is_revoked(sc->hn_prichan)) {
/*
* In case that the vmbus missed the orphan handler
* installation.
*/
vmbus_xact_ctx_orphan(sc->hn_xact);
}
if (device_is_attached(dev)) {
HN_LOCK(sc);
if (sc->hn_flags & HN_FLAG_SYNTH_ATTACHED) {
@ -1195,8 +1223,14 @@ hn_detach(device_t dev)
taskqueue_free(sc->hn_tx_taskq);
taskqueue_free(sc->hn_mgmt_taskq0);
if (sc->hn_xact != NULL)
if (sc->hn_xact != NULL) {
/*
* Uninstall the orphan handler _before_ the xact is
* destructed.
*/
vmbus_chan_unset_orphan(sc->hn_prichan);
vmbus_xact_ctx_destroy(sc->hn_xact);
}
if_free(ifp);
@ -1435,7 +1469,7 @@ hn_txdesc_hold(struct hn_txdesc *txd)
{
/* 0->1 transition will never work */
KASSERT(txd->refs > 0, ("invalid refs %d", txd->refs));
KASSERT(txd->refs > 0, ("invalid txd refs %d", txd->refs));
atomic_add_int(&txd->refs, 1);
}
@ -3448,25 +3482,44 @@ hn_txdesc_dmamap_destroy(struct hn_txdesc *txd)
bus_dmamap_destroy(txr->hn_tx_data_dtag, txd->data_dmap);
}
static void
hn_txdesc_gc(struct hn_tx_ring *txr, struct hn_txdesc *txd)
{
KASSERT(txd->refs == 0 || txd->refs == 1,
("invalid txd refs %d", txd->refs));
/* Aggregated txds will be freed by their aggregating txd. */
if (txd->refs > 0 && (txd->flags & HN_TXD_FLAG_ONAGG) == 0) {
int freed;
freed = hn_txdesc_put(txr, txd);
KASSERT(freed, ("can't free txdesc"));
}
}
static void
hn_tx_ring_destroy(struct hn_tx_ring *txr)
{
struct hn_txdesc *txd;
int i;
if (txr->hn_txdesc == NULL)
return;
#ifndef HN_USE_TXDESC_BUFRING
while ((txd = SLIST_FIRST(&txr->hn_txlist)) != NULL) {
SLIST_REMOVE_HEAD(&txr->hn_txlist, link);
hn_txdesc_dmamap_destroy(txd);
}
#else
mtx_lock(&txr->hn_tx_lock);
while ((txd = buf_ring_dequeue_sc(txr->hn_txdesc_br)) != NULL)
hn_txdesc_dmamap_destroy(txd);
mtx_unlock(&txr->hn_tx_lock);
#endif
/*
* NOTE:
* Because the freeing of aggregated txds will be deferred
* to the aggregating txd, two passes are used here:
* - The first pass GCes any pending txds. This GC is necessary,
* since if the channels are revoked, hypervisor will not
* deliver send-done for all pending txds.
* - The second pass frees the busdma stuffs, i.e. after all txds
* were freed.
*/
for (i = 0; i < txr->hn_txdesc_cnt; ++i)
hn_txdesc_gc(txr, &txr->hn_txdesc[i]);
for (i = 0; i < txr->hn_txdesc_cnt; ++i)
hn_txdesc_dmamap_destroy(&txr->hn_txdesc[i]);
if (txr->hn_tx_data_dtag != NULL)
bus_dma_tag_destroy(txr->hn_tx_data_dtag);
@ -4499,10 +4552,17 @@ hn_set_ring_inuse(struct hn_softc *sc, int ring_cnt)
}
static void
hn_chan_drain(struct vmbus_channel *chan)
hn_chan_drain(struct hn_softc *sc, struct vmbus_channel *chan)
{
while (!vmbus_chan_rx_empty(chan) || !vmbus_chan_tx_empty(chan))
/*
* NOTE:
* The TX bufring will not be drained by the hypervisor,
* if the primary channel is revoked.
*/
while (!vmbus_chan_rx_empty(chan) ||
(!vmbus_chan_is_revoked(sc->hn_prichan) &&
!vmbus_chan_tx_empty(chan)))
pause("waitch", 1);
vmbus_chan_intr_drain(chan);
}
@ -4511,6 +4571,7 @@ static void
hn_suspend_data(struct hn_softc *sc)
{
struct vmbus_channel **subch = NULL;
struct hn_tx_ring *txr;
int i, nsubch;
HN_LOCK_ASSERT(sc);
@ -4519,19 +4580,23 @@ hn_suspend_data(struct hn_softc *sc)
* Suspend TX.
*/
for (i = 0; i < sc->hn_tx_ring_inuse; ++i) {
struct hn_tx_ring *txr = &sc->hn_tx_ring[i];
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))
/*
* Wait for all pending sends to finish.
*
* NOTE:
* We will _not_ receive all pending send-done, if the
* primary channel is revoked.
*/
while (hn_tx_ring_pending(txr) &&
!vmbus_chan_is_revoked(sc->hn_prichan))
pause("hnwtx", 1 /* 1 tick */);
taskqueue_drain(txr->hn_tx_taskq, &txr->hn_tx_task);
taskqueue_drain(txr->hn_tx_taskq, &txr->hn_txeof_task);
}
/*
@ -4554,12 +4619,27 @@ hn_suspend_data(struct hn_softc *sc)
if (subch != NULL) {
for (i = 0; i < nsubch; ++i)
hn_chan_drain(subch[i]);
hn_chan_drain(sc, subch[i]);
}
hn_chan_drain(sc->hn_prichan);
hn_chan_drain(sc, sc->hn_prichan);
if (subch != NULL)
vmbus_subchan_rel(subch, nsubch);
/*
* Drain any pending TX tasks.
*
* NOTE:
* The above hn_chan_drain() can dispatch TX tasks, so the TX
* tasks will have to be drained _after_ the above hn_chan_drain()
* calls.
*/
for (i = 0; i < sc->hn_tx_ring_inuse; ++i) {
txr = &sc->hn_tx_ring[i];
taskqueue_drain(txr->hn_tx_taskq, &txr->hn_tx_task);
taskqueue_drain(txr->hn_tx_taskq, &txr->hn_txeof_task);
}
}
static void