/* * Network-device interface management. * * Copyright (c) 2004-2005, Keir Fraser * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation; or, when distributed * separately from the Linux kernel or incorporated into other * software packages, subject to the following license: * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this source file (the "Software"), to deal in the Software without * restriction, including without limitation the rights to use, copy, modify, * merge, publish, distribute, sublicense, and/or sell copies of the Software, * and to permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ #include "common.h" #include #include #include #include #include #include #include #define XENVIF_QUEUE_LENGTH 32 #define XENVIF_NAPI_WEIGHT 64 static inline void xenvif_stop_queue(struct xenvif_queue *queue) { struct net_device *dev = queue->vif->dev; if (!queue->vif->can_queue) return; netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id)); } int xenvif_schedulable(struct xenvif *vif) { return netif_running(vif->dev) && netif_carrier_ok(vif->dev); } static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id) { struct xenvif_queue *queue = dev_id; if (RING_HAS_UNCONSUMED_REQUESTS(&queue->tx)) napi_schedule(&queue->napi); return IRQ_HANDLED; } int xenvif_poll(struct napi_struct *napi, int budget) { struct xenvif_queue *queue = container_of(napi, struct xenvif_queue, napi); int work_done; /* This vif is rogue, we pretend we've there is nothing to do * for this vif to deschedule it from NAPI. But this interface * will be turned off in thread context later. */ if (unlikely(queue->vif->disabled)) { napi_complete(napi); return 0; } work_done = xenvif_tx_action(queue, budget); if (work_done < budget) { napi_complete(napi); xenvif_napi_schedule_or_enable_events(queue); } return work_done; } static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id) { struct xenvif_queue *queue = dev_id; xenvif_kick_thread(queue); return IRQ_HANDLED; } static irqreturn_t xenvif_interrupt(int irq, void *dev_id) { xenvif_tx_interrupt(irq, dev_id); xenvif_rx_interrupt(irq, dev_id); return IRQ_HANDLED; } int xenvif_queue_stopped(struct xenvif_queue *queue) { struct net_device *dev = queue->vif->dev; unsigned int id = queue->id; return netif_tx_queue_stopped(netdev_get_tx_queue(dev, id)); } void xenvif_wake_queue(struct xenvif_queue *queue) { struct net_device *dev = queue->vif->dev; unsigned int id = queue->id; netif_tx_wake_queue(netdev_get_tx_queue(dev, id)); } /* Callback to wake the queue and drain it on timeout */ static void xenvif_wake_queue_callback(unsigned long data) { struct xenvif_queue *queue = (struct xenvif_queue *)data; if (xenvif_queue_stopped(queue)) { netdev_err(queue->vif->dev, "draining TX queue\n"); queue->rx_queue_purge = true; xenvif_kick_thread(queue); xenvif_wake_queue(queue); } } static u16 xenvif_select_queue(struct net_device *dev, struct sk_buff *skb, void *accel_priv, select_queue_fallback_t fallback) { unsigned int num_queues = dev->real_num_tx_queues; u32 hash; u16 queue_index; /* First, check if there is only one queue to optimise the * single-queue or old frontend scenario. */ if (num_queues == 1) { queue_index = 0; } else { /* Use skb_get_hash to obtain an L4 hash if available */ hash = skb_get_hash(skb); queue_index = hash % num_queues; } return queue_index; } static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct xenvif *vif = netdev_priv(dev); struct xenvif_queue *queue = NULL; unsigned int num_queues = dev->real_num_tx_queues; u16 index; int min_slots_needed; BUG_ON(skb->dev != dev); /* Drop the packet if queues are not set up */ if (num_queues < 1) goto drop; /* Obtain the queue to be used to transmit this packet */ index = skb_get_queue_mapping(skb); if (index >= num_queues) { pr_warn_ratelimited("Invalid queue %hu for packet on interface %s\n.", index, vif->dev->name); index %= num_queues; } queue = &vif->queues[index]; /* Drop the packet if queue is not ready */ if (queue->task == NULL || queue->dealloc_task == NULL || !xenvif_schedulable(vif)) goto drop; /* At best we'll need one slot for the header and one for each * frag. */ min_slots_needed = 1 + skb_shinfo(skb)->nr_frags; /* If the skb is GSO then we'll also need an extra slot for the * metadata. */ if (skb_is_gso(skb)) min_slots_needed++; /* If the skb can't possibly fit in the remaining slots * then turn off the queue to give the ring a chance to * drain. */ if (!xenvif_rx_ring_slots_available(queue, min_slots_needed)) { queue->wake_queue.function = xenvif_wake_queue_callback; queue->wake_queue.data = (unsigned long)queue; xenvif_stop_queue(queue); mod_timer(&queue->wake_queue, jiffies + rx_drain_timeout_jiffies); } skb_queue_tail(&queue->rx_queue, skb); xenvif_kick_thread(queue); return NETDEV_TX_OK; drop: vif->dev->stats.tx_dropped++; dev_kfree_skb(skb); return NETDEV_TX_OK; } static struct net_device_stats *xenvif_get_stats(struct net_device *dev) { struct xenvif *vif = netdev_priv(dev); struct xenvif_queue *queue = NULL; unsigned int num_queues = dev->real_num_tx_queues; unsigned long rx_bytes = 0; unsigned long rx_packets = 0; unsigned long tx_bytes = 0; unsigned long tx_packets = 0; unsigned int index; if (vif->queues == NULL) goto out; /* Aggregate tx and rx stats from each queue */ for (index = 0; index < num_queues; ++index) { queue = &vif->queues[index]; rx_bytes += queue->stats.rx_bytes; rx_packets += queue->stats.rx_packets; tx_bytes += queue->stats.tx_bytes; tx_packets += queue->stats.tx_packets; } out: vif->dev->stats.rx_bytes = rx_bytes; vif->dev->stats.rx_packets = rx_packets; vif->dev->stats.tx_bytes = tx_bytes; vif->dev->stats.tx_packets = tx_packets; return &vif->dev->stats; } static void xenvif_up(struct xenvif *vif) { struct xenvif_queue *queue = NULL; unsigned int num_queues = vif->dev->real_num_tx_queues; unsigned int queue_index; for (queue_index = 0; queue_index < num_queues; ++queue_index) { queue = &vif->queues[queue_index]; napi_enable(&queue->napi); enable_irq(queue->tx_irq); if (queue->tx_irq != queue->rx_irq) enable_irq(queue->rx_irq); xenvif_napi_schedule_or_enable_events(queue); } } static void xenvif_down(struct xenvif *vif) { struct xenvif_queue *queue = NULL; unsigned int num_queues = vif->dev->real_num_tx_queues; unsigned int queue_index; for (queue_index = 0; queue_index < num_queues; ++queue_index) { queue = &vif->queues[queue_index]; napi_disable(&queue->napi); disable_irq(queue->tx_irq); if (queue->tx_irq != queue->rx_irq) disable_irq(queue->rx_irq); del_timer_sync(&queue->credit_timeout); } } static int xenvif_open(struct net_device *dev) { struct xenvif *vif = netdev_priv(dev); if (netif_carrier_ok(dev)) xenvif_up(vif); netif_tx_start_all_queues(dev); return 0; } static int xenvif_close(struct net_device *dev) { struct xenvif *vif = netdev_priv(dev); if (netif_carrier_ok(dev)) xenvif_down(vif); netif_tx_stop_all_queues(dev); return 0; } static int xenvif_change_mtu(struct net_device *dev, int mtu) { struct xenvif *vif = netdev_priv(dev); int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN; if (mtu > max) return -EINVAL; dev->mtu = mtu; return 0; } static netdev_features_t xenvif_fix_features(struct net_device *dev, netdev_features_t features) { struct xenvif *vif = netdev_priv(dev); if (!vif->can_sg) features &= ~NETIF_F_SG; if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV4)) features &= ~NETIF_F_TSO; if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV6)) features &= ~NETIF_F_TSO6; if (!vif->ip_csum) features &= ~NETIF_F_IP_CSUM; if (!vif->ipv6_csum) features &= ~NETIF_F_IPV6_CSUM; return features; } static const struct xenvif_stat { char name[ETH_GSTRING_LEN]; u16 offset; } xenvif_stats[] = { { "rx_gso_checksum_fixup", offsetof(struct xenvif_stats, rx_gso_checksum_fixup) }, /* If (sent != success + fail), there are probably packets never * freed up properly! */ { "tx_zerocopy_sent", offsetof(struct xenvif_stats, tx_zerocopy_sent), }, { "tx_zerocopy_success", offsetof(struct xenvif_stats, tx_zerocopy_success), }, { "tx_zerocopy_fail", offsetof(struct xenvif_stats, tx_zerocopy_fail) }, /* Number of packets exceeding MAX_SKB_FRAG slots. You should use * a guest with the same MAX_SKB_FRAG */ { "tx_frag_overflow", offsetof(struct xenvif_stats, tx_frag_overflow) }, }; static int xenvif_get_sset_count(struct net_device *dev, int string_set) { switch (string_set) { case ETH_SS_STATS: return ARRAY_SIZE(xenvif_stats); default: return -EINVAL; } } static void xenvif_get_ethtool_stats(struct net_device *dev, struct ethtool_stats *stats, u64 * data) { struct xenvif *vif = netdev_priv(dev); unsigned int num_queues = dev->real_num_tx_queues; int i; unsigned int queue_index; struct xenvif_stats *vif_stats; for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) { unsigned long accum = 0; for (queue_index = 0; queue_index < num_queues; ++queue_index) { vif_stats = &vif->queues[queue_index].stats; accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset); } data[i] = accum; } } static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data) { int i; switch (stringset) { case ETH_SS_STATS: for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) memcpy(data + i * ETH_GSTRING_LEN, xenvif_stats[i].name, ETH_GSTRING_LEN); break; } } static const struct ethtool_ops xenvif_ethtool_ops = { .get_link = ethtool_op_get_link, .get_sset_count = xenvif_get_sset_count, .get_ethtool_stats = xenvif_get_ethtool_stats, .get_strings = xenvif_get_strings, }; static const struct net_device_ops xenvif_netdev_ops = { .ndo_start_xmit = xenvif_start_xmit, .ndo_get_stats = xenvif_get_stats, .ndo_open = xenvif_open, .ndo_stop = xenvif_close, .ndo_change_mtu = xenvif_change_mtu, .ndo_fix_features = xenvif_fix_features, .ndo_set_mac_address = eth_mac_addr, .ndo_validate_addr = eth_validate_addr, .ndo_select_queue = xenvif_select_queue, }; struct xenvif *xenvif_alloc(struct device *parent, domid_t domid, unsigned int handle) { int err; struct net_device *dev; struct xenvif *vif; char name[IFNAMSIZ] = {}; snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle); /* Allocate a netdev with the max. supported number of queues. * When the guest selects the desired number, it will be updated * via netif_set_real_num_tx_queues(). */ dev = alloc_netdev_mq(sizeof(struct xenvif), name, ether_setup, xenvif_max_queues); if (dev == NULL) { pr_warn("Could not allocate netdev for %s\n", name); return ERR_PTR(-ENOMEM); } SET_NETDEV_DEV(dev, parent); vif = netdev_priv(dev); vif->domid = domid; vif->handle = handle; vif->can_sg = 1; vif->ip_csum = 1; vif->dev = dev; vif->disabled = false; /* Start out with no queues. The call below does not require * rtnl_lock() as it happens before register_netdev(). */ vif->queues = NULL; netif_set_real_num_tx_queues(dev, 0); dev->netdev_ops = &xenvif_netdev_ops; dev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | NETIF_F_TSO | NETIF_F_TSO6; dev->features = dev->hw_features | NETIF_F_RXCSUM; dev->ethtool_ops = &xenvif_ethtool_ops; dev->tx_queue_len = XENVIF_QUEUE_LENGTH; /* * Initialise a dummy MAC address. We choose the numerically * largest non-broadcast address to prevent the address getting * stolen by an Ethernet bridge for STP purposes. * (FE:FF:FF:FF:FF:FF) */ memset(dev->dev_addr, 0xFF, ETH_ALEN); dev->dev_addr[0] &= ~0x01; netif_carrier_off(dev); err = register_netdev(dev); if (err) { netdev_warn(dev, "Could not register device: err=%d\n", err); free_netdev(dev); return ERR_PTR(err); } netdev_dbg(dev, "Successfully created xenvif\n"); __module_get(THIS_MODULE); return vif; } int xenvif_init_queue(struct xenvif_queue *queue) { int err, i; queue->credit_bytes = queue->remaining_credit = ~0UL; queue->credit_usec = 0UL; init_timer(&queue->credit_timeout); queue->credit_window_start = get_jiffies_64(); skb_queue_head_init(&queue->rx_queue); skb_queue_head_init(&queue->tx_queue); queue->pending_cons = 0; queue->pending_prod = MAX_PENDING_REQS; for (i = 0; i < MAX_PENDING_REQS; ++i) queue->pending_ring[i] = i; spin_lock_init(&queue->callback_lock); spin_lock_init(&queue->response_lock); /* If ballooning is disabled, this will consume real memory, so you * better enable it. The long term solution would be to use just a * bunch of valid page descriptors, without dependency on ballooning */ err = alloc_xenballooned_pages(MAX_PENDING_REQS, queue->mmap_pages, false); if (err) { netdev_err(queue->vif->dev, "Could not reserve mmap_pages\n"); return -ENOMEM; } for (i = 0; i < MAX_PENDING_REQS; i++) { queue->pending_tx_info[i].callback_struct = (struct ubuf_info) { .callback = xenvif_zerocopy_callback, .ctx = NULL, .desc = i }; queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE; } init_timer(&queue->wake_queue); netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll, XENVIF_NAPI_WEIGHT); return 0; } void xenvif_carrier_on(struct xenvif *vif) { rtnl_lock(); if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN) dev_set_mtu(vif->dev, ETH_DATA_LEN); netdev_update_features(vif->dev); netif_carrier_on(vif->dev); if (netif_running(vif->dev)) xenvif_up(vif); rtnl_unlock(); } int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref, unsigned long rx_ring_ref, unsigned int tx_evtchn, unsigned int rx_evtchn) { struct task_struct *task; int err = -ENOMEM; BUG_ON(queue->tx_irq); BUG_ON(queue->task); BUG_ON(queue->dealloc_task); err = xenvif_map_frontend_rings(queue, tx_ring_ref, rx_ring_ref); if (err < 0) goto err; init_waitqueue_head(&queue->wq); init_waitqueue_head(&queue->dealloc_wq); if (tx_evtchn == rx_evtchn) { /* feature-split-event-channels == 0 */ err = bind_interdomain_evtchn_to_irqhandler( queue->vif->domid, tx_evtchn, xenvif_interrupt, 0, queue->name, queue); if (err < 0) goto err_unmap; queue->tx_irq = queue->rx_irq = err; disable_irq(queue->tx_irq); } else { /* feature-split-event-channels == 1 */ snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name), "%s-tx", queue->name); err = bind_interdomain_evtchn_to_irqhandler( queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0, queue->tx_irq_name, queue); if (err < 0) goto err_unmap; queue->tx_irq = err; disable_irq(queue->tx_irq); snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name), "%s-rx", queue->name); err = bind_interdomain_evtchn_to_irqhandler( queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0, queue->rx_irq_name, queue); if (err < 0) goto err_tx_unbind; queue->rx_irq = err; disable_irq(queue->rx_irq); } task = kthread_create(xenvif_kthread_guest_rx, (void *)queue, "%s-guest-rx", queue->name); if (IS_ERR(task)) { pr_warn("Could not allocate kthread for %s\n", queue->name); err = PTR_ERR(task); goto err_rx_unbind; } queue->task = task; task = kthread_create(xenvif_dealloc_kthread, (void *)queue, "%s-dealloc", queue->name); if (IS_ERR(task)) { pr_warn("Could not allocate kthread for %s\n", queue->name); err = PTR_ERR(task); goto err_rx_unbind; } queue->dealloc_task = task; wake_up_process(queue->task); wake_up_process(queue->dealloc_task); return 0; err_rx_unbind: unbind_from_irqhandler(queue->rx_irq, queue); queue->rx_irq = 0; err_tx_unbind: unbind_from_irqhandler(queue->tx_irq, queue); queue->tx_irq = 0; err_unmap: xenvif_unmap_frontend_rings(queue); err: module_put(THIS_MODULE); return err; } void xenvif_carrier_off(struct xenvif *vif) { struct net_device *dev = vif->dev; rtnl_lock(); netif_carrier_off(dev); /* discard queued packets */ if (netif_running(dev)) xenvif_down(vif); rtnl_unlock(); } static void xenvif_wait_unmap_timeout(struct xenvif_queue *queue, unsigned int worst_case_skb_lifetime) { int i, unmap_timeout = 0; for (i = 0; i < MAX_PENDING_REQS; ++i) { if (queue->grant_tx_handle[i] != NETBACK_INVALID_HANDLE) { unmap_timeout++; schedule_timeout(msecs_to_jiffies(1000)); if (unmap_timeout > worst_case_skb_lifetime && net_ratelimit()) netdev_err(queue->vif->dev, "Page still granted! Index: %x\n", i); i = -1; } } } void xenvif_disconnect(struct xenvif *vif) { struct xenvif_queue *queue = NULL; unsigned int num_queues = vif->dev->real_num_tx_queues; unsigned int queue_index; if (netif_carrier_ok(vif->dev)) xenvif_carrier_off(vif); for (queue_index = 0; queue_index < num_queues; ++queue_index) { queue = &vif->queues[queue_index]; if (queue->task) { del_timer_sync(&queue->wake_queue); kthread_stop(queue->task); queue->task = NULL; } if (queue->dealloc_task) { kthread_stop(queue->dealloc_task); queue->dealloc_task = NULL; } if (queue->tx_irq) { if (queue->tx_irq == queue->rx_irq) unbind_from_irqhandler(queue->tx_irq, queue); else { unbind_from_irqhandler(queue->tx_irq, queue); unbind_from_irqhandler(queue->rx_irq, queue); } queue->tx_irq = 0; } xenvif_unmap_frontend_rings(queue); } } /* Reverse the relevant parts of xenvif_init_queue(). * Used for queue teardown from xenvif_free(), and on the * error handling paths in xenbus.c:connect(). */ void xenvif_deinit_queue(struct xenvif_queue *queue) { free_xenballooned_pages(MAX_PENDING_REQS, queue->mmap_pages); netif_napi_del(&queue->napi); } void xenvif_free(struct xenvif *vif) { struct xenvif_queue *queue = NULL; unsigned int num_queues = vif->dev->real_num_tx_queues; unsigned int queue_index; /* Here we want to avoid timeout messages if an skb can be legitimately * stuck somewhere else. Realistically this could be an another vif's * internal or QDisc queue. That another vif also has this * rx_drain_timeout_msecs timeout, but the timer only ditches the * internal queue. After that, the QDisc queue can put in worst case * XEN_NETIF_RX_RING_SIZE / MAX_SKB_FRAGS skbs into that another vif's * internal queue, so we need several rounds of such timeouts until we * can be sure that no another vif should have skb's from us. We are * not sending more skb's, so newly stuck packets are not interesting * for us here. */ unsigned int worst_case_skb_lifetime = (rx_drain_timeout_msecs/1000) * DIV_ROUND_UP(XENVIF_QUEUE_LENGTH, (XEN_NETIF_RX_RING_SIZE / MAX_SKB_FRAGS)); unregister_netdev(vif->dev); for (queue_index = 0; queue_index < num_queues; ++queue_index) { queue = &vif->queues[queue_index]; xenvif_wait_unmap_timeout(queue, worst_case_skb_lifetime); xenvif_deinit_queue(queue); } /* Free the array of queues. The call below does not require * rtnl_lock() because it happens after unregister_netdev(). */ netif_set_real_num_tx_queues(vif->dev, 0); vfree(vif->queues); vif->queues = NULL; free_netdev(vif->dev); module_put(THIS_MODULE); }