diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/net/xen-netback/interface.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | drivers/net/xen-netback/interface.c | 856 |
1 files changed, 856 insertions, 0 deletions
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c new file mode 100644 index 000000000..09fc4bc06 --- /dev/null +++ b/drivers/net/xen-netback/interface.c @@ -0,0 +1,856 @@ +/* + * 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 <linux/kthread.h> +#include <linux/sched/task.h> +#include <linux/ethtool.h> +#include <linux/rtnetlink.h> +#include <linux/if_vlan.h> +#include <linux/vmalloc.h> + +#include <xen/events.h> +#include <asm/xen/hypercall.h> +#include <xen/balloon.h> + +#define XENVIF_NAPI_WEIGHT 64 + +/* Number of bytes allowed on the internal guest Rx queue. */ +#define XENVIF_RX_QUEUE_BYTES (XEN_NETIF_RX_RING_SIZE/2 * PAGE_SIZE) + +/* This function is used to set SKBTX_DEV_ZEROCOPY as well as + * increasing the inflight counter. We need to increase the inflight + * counter because core driver calls into xenvif_zerocopy_callback + * which calls xenvif_skb_zerocopy_complete. + */ +void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue, + struct sk_buff *skb) +{ + skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; + atomic_inc(&queue->inflight_packets); +} + +void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue) +{ + atomic_dec(&queue->inflight_packets); + + /* Wake the dealloc thread _after_ decrementing inflight_packets so + * that if kthread_stop() has already been called, the dealloc thread + * does not wait forever with nothing to wake it. + */ + wake_up(&queue->dealloc_wq); +} + +static int xenvif_schedulable(struct xenvif *vif) +{ + return netif_running(vif->dev) && + test_bit(VIF_STATUS_CONNECTED, &vif->status) && + !vif->disabled; +} + +static bool xenvif_handle_tx_interrupt(struct xenvif_queue *queue) +{ + bool rc; + + rc = RING_HAS_UNCONSUMED_REQUESTS(&queue->tx); + if (rc) + napi_schedule(&queue->napi); + return rc; +} + +static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id) +{ + struct xenvif_queue *queue = dev_id; + int old; + + old = atomic_fetch_or(NETBK_TX_EOI, &queue->eoi_pending); + WARN(old & NETBK_TX_EOI, "Interrupt while EOI pending\n"); + + if (!xenvif_handle_tx_interrupt(queue)) { + atomic_andnot(NETBK_TX_EOI, &queue->eoi_pending); + xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS); + } + + return IRQ_HANDLED; +} + +static 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_done(napi, work_done); + /* If the queue is rate-limited, it shall be + * rescheduled in the timer callback. + */ + if (likely(!queue->rate_limited)) + xenvif_napi_schedule_or_enable_events(queue); + } + + return work_done; +} + +static bool xenvif_handle_rx_interrupt(struct xenvif_queue *queue) +{ + bool rc; + + rc = xenvif_have_rx_work(queue, false); + if (rc) + xenvif_kick_thread(queue); + return rc; +} + +static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id) +{ + struct xenvif_queue *queue = dev_id; + int old; + + old = atomic_fetch_or(NETBK_RX_EOI, &queue->eoi_pending); + WARN(old & NETBK_RX_EOI, "Interrupt while EOI pending\n"); + + if (!xenvif_handle_rx_interrupt(queue)) { + atomic_andnot(NETBK_RX_EOI, &queue->eoi_pending); + xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS); + } + + return IRQ_HANDLED; +} + +irqreturn_t xenvif_interrupt(int irq, void *dev_id) +{ + struct xenvif_queue *queue = dev_id; + int old; + bool has_rx, has_tx; + + old = atomic_fetch_or(NETBK_COMMON_EOI, &queue->eoi_pending); + WARN(old, "Interrupt while EOI pending\n"); + + has_tx = xenvif_handle_tx_interrupt(queue); + has_rx = xenvif_handle_rx_interrupt(queue); + + if (!has_rx && !has_tx) { + atomic_andnot(NETBK_COMMON_EOI, &queue->eoi_pending); + xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS); + } + + return IRQ_HANDLED; +} + +static u16 xenvif_select_queue(struct net_device *dev, struct sk_buff *skb, + struct net_device *sb_dev) +{ + struct xenvif *vif = netdev_priv(dev); + unsigned int size = vif->hash.size; + unsigned int num_queues; + + /* If queues are not set up internally - always return 0 + * as the packet going to be dropped anyway */ + num_queues = READ_ONCE(vif->num_queues); + if (num_queues < 1) + return 0; + + if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE) + return netdev_pick_tx(dev, skb, NULL) % + dev->real_num_tx_queues; + + xenvif_set_skb_hash(vif, skb); + + if (size == 0) + return skb_get_hash_raw(skb) % dev->real_num_tx_queues; + + return vif->hash.mapping[vif->hash.mapping_sel] + [skb_get_hash_raw(skb) % size]; +} + +static netdev_tx_t +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; + u16 index; + struct xenvif_rx_cb *cb; + + BUG_ON(skb->dev != dev); + + /* Drop the packet if queues are not set up. + * This handler should be called inside an RCU read section + * so we don't need to enter it here explicitly. + */ + num_queues = READ_ONCE(vif->num_queues); + 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; + + if (vif->multicast_control && skb->pkt_type == PACKET_MULTICAST) { + struct ethhdr *eth = (struct ethhdr *)skb->data; + + if (!xenvif_mcast_match(vif, eth->h_dest)) + goto drop; + } + + cb = XENVIF_RX_CB(skb); + cb->expires = jiffies + vif->drain_timeout; + + /* If there is no hash algorithm configured then make sure there + * is no hash information in the socket buffer otherwise it + * would be incorrectly forwarded to the frontend. + */ + if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE) + skb_clear_hash(skb); + + if (!xenvif_rx_queue_tail(queue, skb)) + goto drop; + + xenvif_kick_thread(queue); + + return NETDEV_TX_OK; + + drop: + vif->dev->stats.tx_dropped++; + dev_kfree_skb_any(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; + u64 rx_bytes = 0; + u64 rx_packets = 0; + u64 tx_bytes = 0; + u64 tx_packets = 0; + unsigned int index; + + rcu_read_lock(); + num_queues = READ_ONCE(vif->num_queues); + + /* 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; + } + + rcu_read_unlock(); + + 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->num_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->num_queues; + unsigned int queue_index; + + for (queue_index = 0; queue_index < num_queues; ++queue_index) { + queue = &vif->queues[queue_index]; + disable_irq(queue->tx_irq); + if (queue->tx_irq != queue->rx_irq) + disable_irq(queue->rx_irq); + napi_disable(&queue->napi); + del_timer_sync(&queue->credit_timeout); + } +} + +static int xenvif_open(struct net_device *dev) +{ + struct xenvif *vif = netdev_priv(dev); + if (test_bit(VIF_STATUS_CONNECTED, &vif->status)) + 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 (test_bit(VIF_STATUS_CONNECTED, &vif->status)) + 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 ? ETH_MAX_MTU - 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) & GSO_BIT(TCPV4)) + features &= ~NETIF_F_TSO; + if (~(vif->gso_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; + int i; + unsigned int queue_index; + + rcu_read_lock(); + num_queues = READ_ONCE(vif->num_queues); + + for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) { + unsigned long accum = 0; + for (queue_index = 0; queue_index < num_queues; ++queue_index) { + void *vif_stats = &vif->queues[queue_index].stats; + accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset); + } + data[i] = accum; + } + + rcu_read_unlock(); +} + +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_select_queue = xenvif_select_queue, + .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, +}; + +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_*_queues(). + */ + dev = alloc_netdev_mq(sizeof(struct xenvif), name, NET_NAME_UNKNOWN, + 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; + vif->drain_timeout = msecs_to_jiffies(rx_drain_timeout_msecs); + vif->stall_timeout = msecs_to_jiffies(rx_stall_timeout_msecs); + + /* Start out with no queues. */ + vif->queues = NULL; + vif->num_queues = 0; + + vif->xdp_headroom = 0; + + spin_lock_init(&vif->lock); + INIT_LIST_HEAD(&vif->fe_mcast_addr); + + 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 | NETIF_F_FRAGLIST; + dev->features = dev->hw_features | NETIF_F_RXCSUM; + dev->ethtool_ops = &xenvif_ethtool_ops; + + dev->min_mtu = ETH_MIN_MTU; + dev->max_mtu = ETH_MAX_MTU - VLAN_ETH_HLEN; + + /* + * 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) + */ + eth_broadcast_addr(dev->dev_addr); + 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; + timer_setup(&queue->credit_timeout, xenvif_tx_credit_callback, 0); + queue->credit_window_start = get_jiffies_64(); + + queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES; + + 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 = gnttab_alloc_pages(MAX_PENDING_REQS, + queue->mmap_pages); + 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; + } + + 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); + set_bit(VIF_STATUS_CONNECTED, &vif->status); + if (netif_running(vif->dev)) + xenvif_up(vif); + rtnl_unlock(); +} + +int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref, + unsigned int evtchn) +{ + struct net_device *dev = vif->dev; + void *addr; + struct xen_netif_ctrl_sring *shared; + RING_IDX rsp_prod, req_prod; + int err; + + err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif), + &ring_ref, 1, &addr); + if (err) + goto err; + + shared = (struct xen_netif_ctrl_sring *)addr; + rsp_prod = READ_ONCE(shared->rsp_prod); + req_prod = READ_ONCE(shared->req_prod); + + BACK_RING_ATTACH(&vif->ctrl, shared, rsp_prod, XEN_PAGE_SIZE); + + err = -EIO; + if (req_prod - rsp_prod > RING_SIZE(&vif->ctrl)) + goto err_unmap; + + err = bind_interdomain_evtchn_to_irq_lateeoi(vif->domid, evtchn); + if (err < 0) + goto err_unmap; + + vif->ctrl_irq = err; + + xenvif_init_hash(vif); + + err = request_threaded_irq(vif->ctrl_irq, NULL, xenvif_ctrl_irq_fn, + IRQF_ONESHOT, "xen-netback-ctrl", vif); + if (err) { + pr_warn("Could not setup irq handler for %s\n", dev->name); + goto err_deinit; + } + + return 0; + +err_deinit: + xenvif_deinit_hash(vif); + unbind_from_irqhandler(vif->ctrl_irq, vif); + vif->ctrl_irq = 0; + +err_unmap: + xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif), + vif->ctrl.sring); + vif->ctrl.sring = NULL; + +err: + return err; +} + +static void xenvif_disconnect_queue(struct xenvif_queue *queue) +{ + if (queue->task) { + kthread_stop(queue->task); + put_task_struct(queue->task); + queue->task = NULL; + } + + if (queue->dealloc_task) { + kthread_stop(queue->dealloc_task); + queue->dealloc_task = NULL; + } + + if (queue->napi.poll) { + netif_napi_del(&queue->napi); + queue->napi.poll = NULL; + } + + if (queue->tx_irq) { + unbind_from_irqhandler(queue->tx_irq, queue); + if (queue->tx_irq == queue->rx_irq) + queue->rx_irq = 0; + queue->tx_irq = 0; + } + + if (queue->rx_irq) { + unbind_from_irqhandler(queue->rx_irq, queue); + queue->rx_irq = 0; + } + + xenvif_unmap_frontend_data_rings(queue); +} + +int xenvif_connect_data(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; + + BUG_ON(queue->tx_irq); + BUG_ON(queue->task); + BUG_ON(queue->dealloc_task); + + err = xenvif_map_frontend_data_rings(queue, tx_ring_ref, + rx_ring_ref); + if (err < 0) + goto err; + + init_waitqueue_head(&queue->wq); + init_waitqueue_head(&queue->dealloc_wq); + atomic_set(&queue->inflight_packets, 0); + + netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll, + XENVIF_NAPI_WEIGHT); + + queue->stalled = true; + + task = kthread_run(xenvif_kthread_guest_rx, queue, + "%s-guest-rx", queue->name); + if (IS_ERR(task)) + goto kthread_err; + queue->task = task; + /* + * Take a reference to the task in order to prevent it from being freed + * if the thread function returns before kthread_stop is called. + */ + get_task_struct(task); + + task = kthread_run(xenvif_dealloc_kthread, queue, + "%s-dealloc", queue->name); + if (IS_ERR(task)) + goto kthread_err; + queue->dealloc_task = task; + + if (tx_evtchn == rx_evtchn) { + /* feature-split-event-channels == 0 */ + err = bind_interdomain_evtchn_to_irqhandler_lateeoi( + queue->vif->domid, tx_evtchn, xenvif_interrupt, 0, + queue->name, queue); + if (err < 0) + goto err; + 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_lateeoi( + queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0, + queue->tx_irq_name, queue); + if (err < 0) + goto err; + 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_lateeoi( + queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0, + queue->rx_irq_name, queue); + if (err < 0) + goto err; + queue->rx_irq = err; + disable_irq(queue->rx_irq); + } + + return 0; + +kthread_err: + pr_warn("Could not allocate kthread for %s\n", queue->name); + err = PTR_ERR(task); +err: + xenvif_disconnect_queue(queue); + return err; +} + +void xenvif_carrier_off(struct xenvif *vif) +{ + struct net_device *dev = vif->dev; + + rtnl_lock(); + if (test_and_clear_bit(VIF_STATUS_CONNECTED, &vif->status)) { + netif_carrier_off(dev); /* discard queued packets */ + if (netif_running(dev)) + xenvif_down(vif); + } + rtnl_unlock(); +} + +void xenvif_disconnect_data(struct xenvif *vif) +{ + struct xenvif_queue *queue = NULL; + unsigned int num_queues = vif->num_queues; + unsigned int queue_index; + + xenvif_carrier_off(vif); + + for (queue_index = 0; queue_index < num_queues; ++queue_index) { + queue = &vif->queues[queue_index]; + + xenvif_disconnect_queue(queue); + } + + xenvif_mcast_addr_list_free(vif); +} + +void xenvif_disconnect_ctrl(struct xenvif *vif) +{ + if (vif->ctrl_irq) { + xenvif_deinit_hash(vif); + unbind_from_irqhandler(vif->ctrl_irq, vif); + vif->ctrl_irq = 0; + } + + if (vif->ctrl.sring) { + xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif), + vif->ctrl.sring); + vif->ctrl.sring = NULL; + } +} + +/* 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) +{ + gnttab_free_pages(MAX_PENDING_REQS, queue->mmap_pages); +} + +void xenvif_free(struct xenvif *vif) +{ + struct xenvif_queue *queues = vif->queues; + unsigned int num_queues = vif->num_queues; + unsigned int queue_index; + + unregister_netdev(vif->dev); + free_netdev(vif->dev); + + for (queue_index = 0; queue_index < num_queues; ++queue_index) + xenvif_deinit_queue(&queues[queue_index]); + vfree(queues); + + module_put(THIS_MODULE); +} |