1/*
  2 * Network-device interface management.
  3 *
  4 * Copyright (c) 2004-2005, Keir Fraser
  5 *
  6 * This program is free software; you can redistribute it and/or
  7 * modify it under the terms of the GNU General Public License version 2
  8 * as published by the Free Software Foundation; or, when distributed
  9 * separately from the Linux kernel or incorporated into other
 10 * software packages, subject to the following license:
 11 *
 12 * Permission is hereby granted, free of charge, to any person obtaining a copy
 13 * of this source file (the "Software"), to deal in the Software without
 14 * restriction, including without limitation the rights to use, copy, modify,
 15 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
 16 * and to permit persons to whom the Software is furnished to do so, subject to
 17 * the following conditions:
 18 *
 19 * The above copyright notice and this permission notice shall be included in
 20 * all copies or substantial portions of the Software.
 21 *
 22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 24 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 25 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 26 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 27 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 28 * IN THE SOFTWARE.
 29 */
 30
 31#include "common.h"
 32
 33#include <linux/kthread.h>
 34#include <linux/sched/task.h>
 35#include <linux/ethtool.h>
 36#include <linux/rtnetlink.h>
 37#include <linux/if_vlan.h>
 38#include <linux/vmalloc.h>
 39
 40#include <xen/events.h>
 41#include <asm/xen/hypercall.h>
 42#include <xen/balloon.h>
 43
 44#define XENVIF_QUEUE_LENGTH 32
 45#define XENVIF_NAPI_WEIGHT  64
 46
 47/* Number of bytes allowed on the internal guest Rx queue. */
 48#define XENVIF_RX_QUEUE_BYTES (XEN_NETIF_RX_RING_SIZE/2 * PAGE_SIZE)
 49
 50/* This function is used to set SKBTX_DEV_ZEROCOPY as well as
 51 * increasing the inflight counter. We need to increase the inflight
 52 * counter because core driver calls into xenvif_zerocopy_callback
 53 * which calls xenvif_skb_zerocopy_complete.
 54 */
 55void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
 56				 struct sk_buff *skb)
 57{
 58	skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
 59	atomic_inc(&queue->inflight_packets);
 60}
 61
 62void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue)
 63{
 64	atomic_dec(&queue->inflight_packets);
 65
 66	/* Wake the dealloc thread _after_ decrementing inflight_packets so
 67	 * that if kthread_stop() has already been called, the dealloc thread
 68	 * does not wait forever with nothing to wake it.
 69	 */
 70	wake_up(&queue->dealloc_wq);
 71}
 72
 73int xenvif_schedulable(struct xenvif *vif)
 74{
 75	return netif_running(vif->dev) &&
 76		test_bit(VIF_STATUS_CONNECTED, &vif->status) &&
 77		!vif->disabled;
 78}
 79
 80static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
 81{
 82	struct xenvif_queue *queue = dev_id;
 83
 84	if (RING_HAS_UNCONSUMED_REQUESTS(&queue->tx))
 85		napi_schedule(&queue->napi);
 86
 87	return IRQ_HANDLED;
 88}
 89
 90static int xenvif_poll(struct napi_struct *napi, int budget)
 91{
 92	struct xenvif_queue *queue =
 93		container_of(napi, struct xenvif_queue, napi);
 94	int work_done;
 95
 96	/* This vif is rogue, we pretend we've there is nothing to do
 97	 * for this vif to deschedule it from NAPI. But this interface
 98	 * will be turned off in thread context later.
 99	 */
100	if (unlikely(queue->vif->disabled)) {
101		napi_complete(napi);
102		return 0;
103	}
104
105	work_done = xenvif_tx_action(queue, budget);
106
107	if (work_done < budget) {
108		napi_complete_done(napi, work_done);
109		/* If the queue is rate-limited, it shall be
110		 * rescheduled in the timer callback.
111		 */
112		if (likely(!queue->rate_limited))
113			xenvif_napi_schedule_or_enable_events(queue);
114	}
115
116	return work_done;
117}
118
119static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
120{
121	struct xenvif_queue *queue = dev_id;
122
123	xenvif_kick_thread(queue);
124
125	return IRQ_HANDLED;
126}
127
128irqreturn_t xenvif_interrupt(int irq, void *dev_id)
129{
130	xenvif_tx_interrupt(irq, dev_id);
131	xenvif_rx_interrupt(irq, dev_id);
132
133	return IRQ_HANDLED;
134}
135
136int xenvif_queue_stopped(struct xenvif_queue *queue)
137{
138	struct net_device *dev = queue->vif->dev;
139	unsigned int id = queue->id;
140	return netif_tx_queue_stopped(netdev_get_tx_queue(dev, id));
141}
142
143void xenvif_wake_queue(struct xenvif_queue *queue)
144{
145	struct net_device *dev = queue->vif->dev;
146	unsigned int id = queue->id;
147	netif_tx_wake_queue(netdev_get_tx_queue(dev, id));
148}
149
150static u16 xenvif_select_queue(struct net_device *dev, struct sk_buff *skb,
151			       void *accel_priv,
152			       select_queue_fallback_t fallback)
153{
154	struct xenvif *vif = netdev_priv(dev);
155	unsigned int size = vif->hash.size;
156
157	if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE)
158		return fallback(dev, skb) % dev->real_num_tx_queues;
159
160	xenvif_set_skb_hash(vif, skb);
161
162	if (size == 0)
163		return skb_get_hash_raw(skb) % dev->real_num_tx_queues;
164
165	return vif->hash.mapping[skb_get_hash_raw(skb) % size];
166}
167
168static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
169{
170	struct xenvif *vif = netdev_priv(dev);
171	struct xenvif_queue *queue = NULL;
172	unsigned int num_queues;
173	u16 index;
174	struct xenvif_rx_cb *cb;
175
176	BUG_ON(skb->dev != dev);
177
178	/* Drop the packet if queues are not set up.
179	 * This handler should be called inside an RCU read section
180	 * so we don't need to enter it here explicitly.
181	 */
182	num_queues = READ_ONCE(vif->num_queues);
183	if (num_queues < 1)
184		goto drop;
185
186	/* Obtain the queue to be used to transmit this packet */
187	index = skb_get_queue_mapping(skb);
188	if (index >= num_queues) {
189		pr_warn_ratelimited("Invalid queue %hu for packet on interface %s\n",
190				    index, vif->dev->name);
191		index %= num_queues;
192	}
193	queue = &vif->queues[index];
194
195	/* Drop the packet if queue is not ready */
196	if (queue->task == NULL ||
197	    queue->dealloc_task == NULL ||
198	    !xenvif_schedulable(vif))
199		goto drop;
200
201	if (vif->multicast_control && skb->pkt_type == PACKET_MULTICAST) {
202		struct ethhdr *eth = (struct ethhdr *)skb->data;
203
204		if (!xenvif_mcast_match(vif, eth->h_dest))
205			goto drop;
206	}
207
208	cb = XENVIF_RX_CB(skb);
209	cb->expires = jiffies + vif->drain_timeout;
210
211	/* If there is no hash algorithm configured then make sure there
212	 * is no hash information in the socket buffer otherwise it
213	 * would be incorrectly forwarded to the frontend.
214	 */
215	if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE)
216		skb_clear_hash(skb);
217
218	xenvif_rx_queue_tail(queue, skb);
219	xenvif_kick_thread(queue);
220
221	return NETDEV_TX_OK;
222
223 drop:
224	vif->dev->stats.tx_dropped++;
225	dev_kfree_skb(skb);
226	return NETDEV_TX_OK;
227}
228
229static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
230{
231	struct xenvif *vif = netdev_priv(dev);
232	struct xenvif_queue *queue = NULL;
233	unsigned int num_queues;
234	u64 rx_bytes = 0;
235	u64 rx_packets = 0;
236	u64 tx_bytes = 0;
237	u64 tx_packets = 0;
238	unsigned int index;
239
240	rcu_read_lock();
241	num_queues = READ_ONCE(vif->num_queues);
242
243	/* Aggregate tx and rx stats from each queue */
244	for (index = 0; index < num_queues; ++index) {
245		queue = &vif->queues[index];
246		rx_bytes += queue->stats.rx_bytes;
247		rx_packets += queue->stats.rx_packets;
248		tx_bytes += queue->stats.tx_bytes;
249		tx_packets += queue->stats.tx_packets;
250	}
251
252	rcu_read_unlock();
253
254	vif->dev->stats.rx_bytes = rx_bytes;
255	vif->dev->stats.rx_packets = rx_packets;
256	vif->dev->stats.tx_bytes = tx_bytes;
257	vif->dev->stats.tx_packets = tx_packets;
258
259	return &vif->dev->stats;
260}
261
262static void xenvif_up(struct xenvif *vif)
263{
264	struct xenvif_queue *queue = NULL;
265	unsigned int num_queues = vif->num_queues;
266	unsigned int queue_index;
267
268	for (queue_index = 0; queue_index < num_queues; ++queue_index) {
269		queue = &vif->queues[queue_index];
270		napi_enable(&queue->napi);
271		enable_irq(queue->tx_irq);
272		if (queue->tx_irq != queue->rx_irq)
273			enable_irq(queue->rx_irq);
274		xenvif_napi_schedule_or_enable_events(queue);
275	}
276}
277
278static void xenvif_down(struct xenvif *vif)
279{
280	struct xenvif_queue *queue = NULL;
281	unsigned int num_queues = vif->num_queues;
282	unsigned int queue_index;
283
284	for (queue_index = 0; queue_index < num_queues; ++queue_index) {
285		queue = &vif->queues[queue_index];
286		disable_irq(queue->tx_irq);
287		if (queue->tx_irq != queue->rx_irq)
288			disable_irq(queue->rx_irq);
289		napi_disable(&queue->napi);
290		del_timer_sync(&queue->credit_timeout);
291	}
292}
293
294static int xenvif_open(struct net_device *dev)
295{
296	struct xenvif *vif = netdev_priv(dev);
297	if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
298		xenvif_up(vif);
299	netif_tx_start_all_queues(dev);
300	return 0;
301}
302
303static int xenvif_close(struct net_device *dev)
304{
305	struct xenvif *vif = netdev_priv(dev);
306	if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
307		xenvif_down(vif);
308	netif_tx_stop_all_queues(dev);
309	return 0;
310}
311
312static int xenvif_change_mtu(struct net_device *dev, int mtu)
313{
314	struct xenvif *vif = netdev_priv(dev);
315	int max = vif->can_sg ? ETH_MAX_MTU - VLAN_ETH_HLEN : ETH_DATA_LEN;
316
317	if (mtu > max)
318		return -EINVAL;
319	dev->mtu = mtu;
320	return 0;
321}
322
323static netdev_features_t xenvif_fix_features(struct net_device *dev,
324	netdev_features_t features)
325{
326	struct xenvif *vif = netdev_priv(dev);
327
328	if (!vif->can_sg)
329		features &= ~NETIF_F_SG;
330	if (~(vif->gso_mask) & GSO_BIT(TCPV4))
331		features &= ~NETIF_F_TSO;
332	if (~(vif->gso_mask) & GSO_BIT(TCPV6))
333		features &= ~NETIF_F_TSO6;
334	if (!vif->ip_csum)
335		features &= ~NETIF_F_IP_CSUM;
336	if (!vif->ipv6_csum)
337		features &= ~NETIF_F_IPV6_CSUM;
338
339	return features;
340}
341
342static const struct xenvif_stat {
343	char name[ETH_GSTRING_LEN];
344	u16 offset;
345} xenvif_stats[] = {
346	{
347		"rx_gso_checksum_fixup",
348		offsetof(struct xenvif_stats, rx_gso_checksum_fixup)
349	},
350	/* If (sent != success + fail), there are probably packets never
351	 * freed up properly!
352	 */
353	{
354		"tx_zerocopy_sent",
355		offsetof(struct xenvif_stats, tx_zerocopy_sent),
356	},
357	{
358		"tx_zerocopy_success",
359		offsetof(struct xenvif_stats, tx_zerocopy_success),
360	},
361	{
362		"tx_zerocopy_fail",
363		offsetof(struct xenvif_stats, tx_zerocopy_fail)
364	},
365	/* Number of packets exceeding MAX_SKB_FRAG slots. You should use
366	 * a guest with the same MAX_SKB_FRAG
367	 */
368	{
369		"tx_frag_overflow",
370		offsetof(struct xenvif_stats, tx_frag_overflow)
371	},
372};
373
374static int xenvif_get_sset_count(struct net_device *dev, int string_set)
375{
376	switch (string_set) {
377	case ETH_SS_STATS:
378		return ARRAY_SIZE(xenvif_stats);
379	default:
380		return -EINVAL;
381	}
382}
383
384static void xenvif_get_ethtool_stats(struct net_device *dev,
385				     struct ethtool_stats *stats, u64 * data)
386{
387	struct xenvif *vif = netdev_priv(dev);
388	unsigned int num_queues;
389	int i;
390	unsigned int queue_index;
391
392	rcu_read_lock();
393	num_queues = READ_ONCE(vif->num_queues);
394
395	for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) {
396		unsigned long accum = 0;
397		for (queue_index = 0; queue_index < num_queues; ++queue_index) {
398			void *vif_stats = &vif->queues[queue_index].stats;
399			accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset);
400		}
401		data[i] = accum;
402	}
403
404	rcu_read_unlock();
405}
406
407static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
408{
409	int i;
410
411	switch (stringset) {
412	case ETH_SS_STATS:
413		for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
414			memcpy(data + i * ETH_GSTRING_LEN,
415			       xenvif_stats[i].name, ETH_GSTRING_LEN);
416		break;
417	}
418}
419
420static const struct ethtool_ops xenvif_ethtool_ops = {
421	.get_link	= ethtool_op_get_link,
422
423	.get_sset_count = xenvif_get_sset_count,
424	.get_ethtool_stats = xenvif_get_ethtool_stats,
425	.get_strings = xenvif_get_strings,
426};
427
428static const struct net_device_ops xenvif_netdev_ops = {
429	.ndo_select_queue = xenvif_select_queue,
430	.ndo_start_xmit	= xenvif_start_xmit,
431	.ndo_get_stats	= xenvif_get_stats,
432	.ndo_open	= xenvif_open,
433	.ndo_stop	= xenvif_close,
434	.ndo_change_mtu	= xenvif_change_mtu,
435	.ndo_fix_features = xenvif_fix_features,
436	.ndo_set_mac_address = eth_mac_addr,
437	.ndo_validate_addr   = eth_validate_addr,
438};
439
440struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
441			    unsigned int handle)
442{
443	int err;
444	struct net_device *dev;
445	struct xenvif *vif;
446	char name[IFNAMSIZ] = {};
447
448	snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
449	/* Allocate a netdev with the max. supported number of queues.
450	 * When the guest selects the desired number, it will be updated
451	 * via netif_set_real_num_*_queues().
452	 */
453	dev = alloc_netdev_mq(sizeof(struct xenvif), name, NET_NAME_UNKNOWN,
454			      ether_setup, xenvif_max_queues);
455	if (dev == NULL) {
456		pr_warn("Could not allocate netdev for %s\n", name);
457		return ERR_PTR(-ENOMEM);
458	}
459
460	SET_NETDEV_DEV(dev, parent);
461
462	vif = netdev_priv(dev);
463
464	vif->domid  = domid;
465	vif->handle = handle;
466	vif->can_sg = 1;
467	vif->ip_csum = 1;
468	vif->dev = dev;
469	vif->disabled = false;
470	vif->drain_timeout = msecs_to_jiffies(rx_drain_timeout_msecs);
471	vif->stall_timeout = msecs_to_jiffies(rx_stall_timeout_msecs);
472
473	/* Start out with no queues. */
474	vif->queues = NULL;
475	vif->num_queues = 0;
476
477	spin_lock_init(&vif->lock);
478	INIT_LIST_HEAD(&vif->fe_mcast_addr);
479
480	dev->netdev_ops	= &xenvif_netdev_ops;
481	dev->hw_features = NETIF_F_SG |
482		NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
483		NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_FRAGLIST;
484	dev->features = dev->hw_features | NETIF_F_RXCSUM;
485	dev->ethtool_ops = &xenvif_ethtool_ops;
486
487	dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
488
489	dev->min_mtu = ETH_MIN_MTU;
490	dev->max_mtu = ETH_MAX_MTU - VLAN_ETH_HLEN;
491
492	/*
493	 * Initialise a dummy MAC address. We choose the numerically
494	 * largest non-broadcast address to prevent the address getting
495	 * stolen by an Ethernet bridge for STP purposes.
496	 * (FE:FF:FF:FF:FF:FF)
497	 */
498	eth_broadcast_addr(dev->dev_addr);
499	dev->dev_addr[0] &= ~0x01;
500
501	netif_carrier_off(dev);
502
503	err = register_netdev(dev);
504	if (err) {
505		netdev_warn(dev, "Could not register device: err=%d\n", err);
506		free_netdev(dev);
507		return ERR_PTR(err);
508	}
509
510	netdev_dbg(dev, "Successfully created xenvif\n");
511
512	__module_get(THIS_MODULE);
513
514	return vif;
515}
516
517int xenvif_init_queue(struct xenvif_queue *queue)
518{
519	int err, i;
520
521	queue->credit_bytes = queue->remaining_credit = ~0UL;
522	queue->credit_usec  = 0UL;
523	timer_setup(&queue->credit_timeout, xenvif_tx_credit_callback, 0);
 
524	queue->credit_window_start = get_jiffies_64();
525
526	queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES;
527
528	skb_queue_head_init(&queue->rx_queue);
529	skb_queue_head_init(&queue->tx_queue);
530
531	queue->pending_cons = 0;
532	queue->pending_prod = MAX_PENDING_REQS;
533	for (i = 0; i < MAX_PENDING_REQS; ++i)
534		queue->pending_ring[i] = i;
535
536	spin_lock_init(&queue->callback_lock);
537	spin_lock_init(&queue->response_lock);
538
539	/* If ballooning is disabled, this will consume real memory, so you
540	 * better enable it. The long term solution would be to use just a
541	 * bunch of valid page descriptors, without dependency on ballooning
542	 */
543	err = gnttab_alloc_pages(MAX_PENDING_REQS,
544				 queue->mmap_pages);
545	if (err) {
546		netdev_err(queue->vif->dev, "Could not reserve mmap_pages\n");
547		return -ENOMEM;
548	}
549
550	for (i = 0; i < MAX_PENDING_REQS; i++) {
551		queue->pending_tx_info[i].callback_struct = (struct ubuf_info)
552			{ .callback = xenvif_zerocopy_callback,
553			  { { .ctx = NULL,
554			      .desc = i } } };
555		queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE;
556	}
557
558	return 0;
559}
560
561void xenvif_carrier_on(struct xenvif *vif)
562{
563	rtnl_lock();
564	if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
565		dev_set_mtu(vif->dev, ETH_DATA_LEN);
566	netdev_update_features(vif->dev);
567	set_bit(VIF_STATUS_CONNECTED, &vif->status);
568	if (netif_running(vif->dev))
569		xenvif_up(vif);
570	rtnl_unlock();
571}
572
573int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref,
574			unsigned int evtchn)
575{
576	struct net_device *dev = vif->dev;
577	void *addr;
578	struct xen_netif_ctrl_sring *shared;
579	int err;
580
581	err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
582				     &ring_ref, 1, &addr);
583	if (err)
584		goto err;
585
586	shared = (struct xen_netif_ctrl_sring *)addr;
587	BACK_RING_INIT(&vif->ctrl, shared, XEN_PAGE_SIZE);
588
589	err = bind_interdomain_evtchn_to_irq(vif->domid, evtchn);
590	if (err < 0)
591		goto err_unmap;
592
593	vif->ctrl_irq = err;
594
595	xenvif_init_hash(vif);
596
597	err = request_threaded_irq(vif->ctrl_irq, NULL, xenvif_ctrl_irq_fn,
598				   IRQF_ONESHOT, "xen-netback-ctrl", vif);
599	if (err) {
600		pr_warn("Could not setup irq handler for %s\n", dev->name);
601		goto err_deinit;
602	}
603
604	return 0;
605
606err_deinit:
607	xenvif_deinit_hash(vif);
608	unbind_from_irqhandler(vif->ctrl_irq, vif);
609	vif->ctrl_irq = 0;
610
611err_unmap:
612	xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
613				vif->ctrl.sring);
614	vif->ctrl.sring = NULL;
615
616err:
617	return err;
618}
619
620int xenvif_connect_data(struct xenvif_queue *queue,
621			unsigned long tx_ring_ref,
622			unsigned long rx_ring_ref,
623			unsigned int tx_evtchn,
624			unsigned int rx_evtchn)
625{
626	struct task_struct *task;
627	int err = -ENOMEM;
628
629	BUG_ON(queue->tx_irq);
630	BUG_ON(queue->task);
631	BUG_ON(queue->dealloc_task);
632
633	err = xenvif_map_frontend_data_rings(queue, tx_ring_ref,
634					     rx_ring_ref);
635	if (err < 0)
636		goto err;
637
638	init_waitqueue_head(&queue->wq);
639	init_waitqueue_head(&queue->dealloc_wq);
640	atomic_set(&queue->inflight_packets, 0);
641
642	netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll,
643			XENVIF_NAPI_WEIGHT);
644
645	if (tx_evtchn == rx_evtchn) {
646		/* feature-split-event-channels == 0 */
647		err = bind_interdomain_evtchn_to_irqhandler(
648			queue->vif->domid, tx_evtchn, xenvif_interrupt, 0,
649			queue->name, queue);
650		if (err < 0)
651			goto err_unmap;
652		queue->tx_irq = queue->rx_irq = err;
653		disable_irq(queue->tx_irq);
654	} else {
655		/* feature-split-event-channels == 1 */
656		snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
657			 "%s-tx", queue->name);
658		err = bind_interdomain_evtchn_to_irqhandler(
659			queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
660			queue->tx_irq_name, queue);
661		if (err < 0)
662			goto err_unmap;
663		queue->tx_irq = err;
664		disable_irq(queue->tx_irq);
665
666		snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
667			 "%s-rx", queue->name);
668		err = bind_interdomain_evtchn_to_irqhandler(
669			queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
670			queue->rx_irq_name, queue);
671		if (err < 0)
672			goto err_tx_unbind;
673		queue->rx_irq = err;
674		disable_irq(queue->rx_irq);
675	}
676
677	queue->stalled = true;
678
679	task = kthread_create(xenvif_kthread_guest_rx,
680			      (void *)queue, "%s-guest-rx", queue->name);
681	if (IS_ERR(task)) {
682		pr_warn("Could not allocate kthread for %s\n", queue->name);
683		err = PTR_ERR(task);
684		goto err_rx_unbind;
685	}
686	queue->task = task;
687	get_task_struct(task);
688
689	task = kthread_create(xenvif_dealloc_kthread,
690			      (void *)queue, "%s-dealloc", queue->name);
691	if (IS_ERR(task)) {
692		pr_warn("Could not allocate kthread for %s\n", queue->name);
693		err = PTR_ERR(task);
694		goto err_rx_unbind;
695	}
696	queue->dealloc_task = task;
697
698	wake_up_process(queue->task);
699	wake_up_process(queue->dealloc_task);
700
701	return 0;
702
703err_rx_unbind:
704	unbind_from_irqhandler(queue->rx_irq, queue);
705	queue->rx_irq = 0;
706err_tx_unbind:
707	unbind_from_irqhandler(queue->tx_irq, queue);
708	queue->tx_irq = 0;
709err_unmap:
710	xenvif_unmap_frontend_data_rings(queue);
711	netif_napi_del(&queue->napi);
712err:
713	module_put(THIS_MODULE);
714	return err;
715}
716
717void xenvif_carrier_off(struct xenvif *vif)
718{
719	struct net_device *dev = vif->dev;
720
721	rtnl_lock();
722	if (test_and_clear_bit(VIF_STATUS_CONNECTED, &vif->status)) {
723		netif_carrier_off(dev); /* discard queued packets */
724		if (netif_running(dev))
725			xenvif_down(vif);
726	}
727	rtnl_unlock();
728}
729
730void xenvif_disconnect_data(struct xenvif *vif)
731{
732	struct xenvif_queue *queue = NULL;
733	unsigned int num_queues = vif->num_queues;
734	unsigned int queue_index;
735
736	xenvif_carrier_off(vif);
737
738	for (queue_index = 0; queue_index < num_queues; ++queue_index) {
739		queue = &vif->queues[queue_index];
740
741		netif_napi_del(&queue->napi);
742
743		if (queue->task) {
744			kthread_stop(queue->task);
745			put_task_struct(queue->task);
746			queue->task = NULL;
747		}
748
749		if (queue->dealloc_task) {
750			kthread_stop(queue->dealloc_task);
751			queue->dealloc_task = NULL;
752		}
753
754		if (queue->tx_irq) {
755			if (queue->tx_irq == queue->rx_irq)
756				unbind_from_irqhandler(queue->tx_irq, queue);
757			else {
758				unbind_from_irqhandler(queue->tx_irq, queue);
759				unbind_from_irqhandler(queue->rx_irq, queue);
760			}
761			queue->tx_irq = 0;
762		}
763
764		xenvif_unmap_frontend_data_rings(queue);
765	}
766
767	xenvif_mcast_addr_list_free(vif);
768}
769
770void xenvif_disconnect_ctrl(struct xenvif *vif)
771{
772	if (vif->ctrl_irq) {
773		xenvif_deinit_hash(vif);
774		unbind_from_irqhandler(vif->ctrl_irq, vif);
775		vif->ctrl_irq = 0;
776	}
777
778	if (vif->ctrl.sring) {
779		xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
780					vif->ctrl.sring);
781		vif->ctrl.sring = NULL;
782	}
783}
784
785/* Reverse the relevant parts of xenvif_init_queue().
786 * Used for queue teardown from xenvif_free(), and on the
787 * error handling paths in xenbus.c:connect().
788 */
789void xenvif_deinit_queue(struct xenvif_queue *queue)
790{
791	gnttab_free_pages(MAX_PENDING_REQS, queue->mmap_pages);
792}
793
794void xenvif_free(struct xenvif *vif)
795{
796	struct xenvif_queue *queues = vif->queues;
797	unsigned int num_queues = vif->num_queues;
798	unsigned int queue_index;
799
800	unregister_netdev(vif->dev);
801	free_netdev(vif->dev);
802
803	for (queue_index = 0; queue_index < num_queues; ++queue_index)
804		xenvif_deinit_queue(&queues[queue_index]);
805	vfree(queues);
806
807	module_put(THIS_MODULE);
808}