diff options
| -rw-r--r-- | drivers/net/xen-netback/common.h | 5 | ||||
| -rw-r--r-- | drivers/net/xen-netback/interface.c | 5 | ||||
| -rw-r--r-- | drivers/net/xen-netback/netback.c | 76 | ||||
| -rw-r--r-- | drivers/net/xen-netback/xenbus.c | 1 |
4 files changed, 86 insertions, 1 deletions
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index c2642402b7a1..083ecc93fe5e 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -179,6 +179,8 @@ struct xenvif_queue { /* Per-queue data for xenvif */ unsigned int rx_queue_max; unsigned int rx_queue_len; + unsigned long last_rx_time; + bool stalled; struct gnttab_copy grant_copy_op[MAX_GRANT_COPY_OPS]; @@ -232,6 +234,9 @@ struct xenvif { /* Queues */ struct xenvif_queue *queues; unsigned int num_queues; /* active queues, resource allocated */ + unsigned int stalled_queues; + + spinlock_t lock; #ifdef CONFIG_DEBUG_FS struct dentry *xenvif_dbg_root; diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index a134d52f55b4..895fe84011e7 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -419,6 +419,8 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid, vif->queues = NULL; vif->num_queues = 0; + spin_lock_init(&vif->lock); + dev->netdev_ops = &xenvif_netdev_ops; dev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | @@ -505,7 +507,6 @@ void xenvif_carrier_on(struct xenvif *vif) dev_set_mtu(vif->dev, ETH_DATA_LEN); netdev_update_features(vif->dev); set_bit(VIF_STATUS_CONNECTED, &vif->status); - netif_carrier_on(vif->dev); if (netif_running(vif->dev)) xenvif_up(vif); rtnl_unlock(); @@ -565,6 +566,8 @@ int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref, disable_irq(queue->rx_irq); } + queue->stalled = true; + task = kthread_create(xenvif_kthread_guest_rx, (void *)queue, "%s-guest-rx", queue->name); if (IS_ERR(task)) { diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 57aa3b507d32..6563f0713fc0 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -62,6 +62,13 @@ unsigned int rx_drain_timeout_msecs = 10000; module_param(rx_drain_timeout_msecs, uint, 0444); unsigned int rx_drain_timeout_jiffies; +/* The length of time before the frontend is considered unresponsive + * because it isn't providing Rx slots. + */ +static unsigned int rx_stall_timeout_msecs = 60000; +module_param(rx_stall_timeout_msecs, uint, 0444); +static unsigned int rx_stall_timeout_jiffies; + unsigned int xenvif_max_queues; module_param_named(max_queues, xenvif_max_queues, uint, 0644); MODULE_PARM_DESC(max_queues, @@ -649,6 +656,8 @@ static void xenvif_rx_action(struct xenvif_queue *queue) RING_IDX ring_slots_used; int i; + queue->last_rx_time = jiffies; + /* We need a cheap worse case estimate for the number of * slots we'll use. */ @@ -1972,10 +1981,67 @@ err: return err; } +static void xenvif_queue_carrier_off(struct xenvif_queue *queue) +{ + struct xenvif *vif = queue->vif; + + queue->stalled = true; + + /* At least one queue has stalled? Disable the carrier. */ + spin_lock(&vif->lock); + if (vif->stalled_queues++ == 0) { + netdev_info(vif->dev, "Guest Rx stalled"); + netif_carrier_off(vif->dev); + } + spin_unlock(&vif->lock); +} + +static void xenvif_queue_carrier_on(struct xenvif_queue *queue) +{ + struct xenvif *vif = queue->vif; + + queue->last_rx_time = jiffies; /* Reset Rx stall detection. */ + queue->stalled = false; + + /* All queues are ready? Enable the carrier. */ + spin_lock(&vif->lock); + if (--vif->stalled_queues == 0) { + netdev_info(vif->dev, "Guest Rx ready"); + netif_carrier_on(vif->dev); + } + spin_unlock(&vif->lock); +} + +static bool xenvif_rx_queue_stalled(struct xenvif_queue *queue) +{ + RING_IDX prod, cons; + + prod = queue->rx.sring->req_prod; + cons = queue->rx.req_cons; + + return !queue->stalled + && prod - cons < XEN_NETBK_RX_SLOTS_MAX + && time_after(jiffies, + queue->last_rx_time + rx_stall_timeout_jiffies); +} + +static bool xenvif_rx_queue_ready(struct xenvif_queue *queue) +{ + RING_IDX prod, cons; + + prod = queue->rx.sring->req_prod; + cons = queue->rx.req_cons; + + return queue->stalled + && prod - cons >= XEN_NETBK_RX_SLOTS_MAX; +} + static bool xenvif_have_rx_work(struct xenvif_queue *queue) { return (!skb_queue_empty(&queue->rx_queue) && xenvif_rx_ring_slots_available(queue, XEN_NETBK_RX_SLOTS_MAX)) + || xenvif_rx_queue_stalled(queue) + || xenvif_rx_queue_ready(queue) || kthread_should_stop() || queue->vif->disabled; } @@ -2050,6 +2116,15 @@ int xenvif_kthread_guest_rx(void *data) if (!skb_queue_empty(&queue->rx_queue)) xenvif_rx_action(queue); + /* If the guest hasn't provided any Rx slots for a + * while it's probably not responsive, drop the + * carrier so packets are dropped earlier. + */ + if (xenvif_rx_queue_stalled(queue)) + xenvif_queue_carrier_off(queue); + else if (xenvif_rx_queue_ready(queue)) + xenvif_queue_carrier_on(queue); + /* Queued packets may have foreign pages from other * domains. These cannot be queued indefinitely as * this would starve guests of grant refs and transmit @@ -2120,6 +2195,7 @@ static int __init netback_init(void) goto failed_init; rx_drain_timeout_jiffies = msecs_to_jiffies(rx_drain_timeout_msecs); + rx_stall_timeout_jiffies = msecs_to_jiffies(rx_stall_timeout_msecs); #ifdef CONFIG_DEBUG_FS xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL); diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 96a754d8e517..4e56a27f9689 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -711,6 +711,7 @@ static void connect(struct backend_info *be) be->vif->queues = vzalloc(requested_num_queues * sizeof(struct xenvif_queue)); be->vif->num_queues = requested_num_queues; + be->vif->stalled_queues = requested_num_queues; for (queue_index = 0; queue_index < requested_num_queues; ++queue_index) { queue = &be->vif->queues[queue_index]; |