2 * Network-device interface management.
4 * Copyright (c) 2004-2005, Keir Fraser
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:
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:
19 * The above copyright notice and this permission notice shall be included in
20 * all copies or substantial portions of the Software.
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
33 #include <linux/kthread.h>
34 #include <linux/ethtool.h>
35 #include <linux/rtnetlink.h>
36 #include <linux/if_vlan.h>
37 #include <linux/vmalloc.h>
39 #include <xen/events.h>
40 #include <asm/xen/hypercall.h>
41 #include <xen/balloon.h>
43 #define XENVIF_QUEUE_LENGTH 32
44 #define XENVIF_NAPI_WEIGHT 64
46 /* Number of bytes allowed on the internal guest Rx queue. */
47 #define XENVIF_RX_QUEUE_BYTES (XEN_NETIF_RX_RING_SIZE/2 * PAGE_SIZE)
49 /* This function is used to set SKBTX_DEV_ZEROCOPY as well as
50 * increasing the inflight counter. We need to increase the inflight
51 * counter because core driver calls into xenvif_zerocopy_callback
52 * which calls xenvif_skb_zerocopy_complete.
54 void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
57 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
58 atomic_inc(&queue->inflight_packets);
61 void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue)
63 atomic_dec(&queue->inflight_packets);
65 /* Wake the dealloc thread _after_ decrementing inflight_packets so
66 * that if kthread_stop() has already been called, the dealloc thread
67 * does not wait forever with nothing to wake it.
69 wake_up(&queue->dealloc_wq);
72 int xenvif_schedulable(struct xenvif *vif)
74 return netif_running(vif->dev) &&
75 test_bit(VIF_STATUS_CONNECTED, &vif->status) &&
79 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
81 struct xenvif_queue *queue = dev_id;
83 if (RING_HAS_UNCONSUMED_REQUESTS(&queue->tx))
84 napi_schedule(&queue->napi);
89 static int xenvif_poll(struct napi_struct *napi, int budget)
91 struct xenvif_queue *queue =
92 container_of(napi, struct xenvif_queue, napi);
95 /* This vif is rogue, we pretend we've there is nothing to do
96 * for this vif to deschedule it from NAPI. But this interface
97 * will be turned off in thread context later.
99 if (unlikely(queue->vif->disabled)) {
104 work_done = xenvif_tx_action(queue, budget);
106 if (work_done < budget) {
108 xenvif_napi_schedule_or_enable_events(queue);
114 static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
116 struct xenvif_queue *queue = dev_id;
118 xenvif_kick_thread(queue);
123 irqreturn_t xenvif_interrupt(int irq, void *dev_id)
125 xenvif_tx_interrupt(irq, dev_id);
126 xenvif_rx_interrupt(irq, dev_id);
131 int xenvif_queue_stopped(struct xenvif_queue *queue)
133 struct net_device *dev = queue->vif->dev;
134 unsigned int id = queue->id;
135 return netif_tx_queue_stopped(netdev_get_tx_queue(dev, id));
138 void xenvif_wake_queue(struct xenvif_queue *queue)
140 struct net_device *dev = queue->vif->dev;
141 unsigned int id = queue->id;
142 netif_tx_wake_queue(netdev_get_tx_queue(dev, id));
145 static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
147 struct xenvif *vif = netdev_priv(dev);
148 struct xenvif_queue *queue = NULL;
149 unsigned int num_queues = vif->num_queues;
151 struct xenvif_rx_cb *cb;
153 BUG_ON(skb->dev != dev);
155 /* Drop the packet if queues are not set up */
159 /* Obtain the queue to be used to transmit this packet */
160 index = skb_get_queue_mapping(skb);
161 if (index >= num_queues) {
162 pr_warn_ratelimited("Invalid queue %hu for packet on interface %s\n.",
163 index, vif->dev->name);
166 queue = &vif->queues[index];
168 /* Drop the packet if queue is not ready */
169 if (queue->task == NULL ||
170 queue->dealloc_task == NULL ||
171 !xenvif_schedulable(vif))
174 cb = XENVIF_RX_CB(skb);
175 cb->expires = jiffies + vif->drain_timeout;
177 xenvif_rx_queue_tail(queue, skb);
178 xenvif_kick_thread(queue);
183 vif->dev->stats.tx_dropped++;
188 static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
190 struct xenvif *vif = netdev_priv(dev);
191 struct xenvif_queue *queue = NULL;
192 unsigned int num_queues = vif->num_queues;
193 unsigned long rx_bytes = 0;
194 unsigned long rx_packets = 0;
195 unsigned long tx_bytes = 0;
196 unsigned long tx_packets = 0;
199 if (vif->queues == NULL)
202 /* Aggregate tx and rx stats from each queue */
203 for (index = 0; index < num_queues; ++index) {
204 queue = &vif->queues[index];
205 rx_bytes += queue->stats.rx_bytes;
206 rx_packets += queue->stats.rx_packets;
207 tx_bytes += queue->stats.tx_bytes;
208 tx_packets += queue->stats.tx_packets;
212 vif->dev->stats.rx_bytes = rx_bytes;
213 vif->dev->stats.rx_packets = rx_packets;
214 vif->dev->stats.tx_bytes = tx_bytes;
215 vif->dev->stats.tx_packets = tx_packets;
217 return &vif->dev->stats;
220 static void xenvif_up(struct xenvif *vif)
222 struct xenvif_queue *queue = NULL;
223 unsigned int num_queues = vif->num_queues;
224 unsigned int queue_index;
226 for (queue_index = 0; queue_index < num_queues; ++queue_index) {
227 queue = &vif->queues[queue_index];
228 napi_enable(&queue->napi);
229 enable_irq(queue->tx_irq);
230 if (queue->tx_irq != queue->rx_irq)
231 enable_irq(queue->rx_irq);
232 xenvif_napi_schedule_or_enable_events(queue);
236 static void xenvif_down(struct xenvif *vif)
238 struct xenvif_queue *queue = NULL;
239 unsigned int num_queues = vif->num_queues;
240 unsigned int queue_index;
242 for (queue_index = 0; queue_index < num_queues; ++queue_index) {
243 queue = &vif->queues[queue_index];
244 disable_irq(queue->tx_irq);
245 if (queue->tx_irq != queue->rx_irq)
246 disable_irq(queue->rx_irq);
247 napi_disable(&queue->napi);
248 del_timer_sync(&queue->credit_timeout);
252 static int xenvif_open(struct net_device *dev)
254 struct xenvif *vif = netdev_priv(dev);
255 if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
257 netif_tx_start_all_queues(dev);
261 static int xenvif_close(struct net_device *dev)
263 struct xenvif *vif = netdev_priv(dev);
264 if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
266 netif_tx_stop_all_queues(dev);
270 static int xenvif_change_mtu(struct net_device *dev, int mtu)
272 struct xenvif *vif = netdev_priv(dev);
273 int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN;
281 static netdev_features_t xenvif_fix_features(struct net_device *dev,
282 netdev_features_t features)
284 struct xenvif *vif = netdev_priv(dev);
287 features &= ~NETIF_F_SG;
288 if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV4))
289 features &= ~NETIF_F_TSO;
290 if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV6))
291 features &= ~NETIF_F_TSO6;
293 features &= ~NETIF_F_IP_CSUM;
295 features &= ~NETIF_F_IPV6_CSUM;
300 static const struct xenvif_stat {
301 char name[ETH_GSTRING_LEN];
305 "rx_gso_checksum_fixup",
306 offsetof(struct xenvif_stats, rx_gso_checksum_fixup)
308 /* If (sent != success + fail), there are probably packets never
313 offsetof(struct xenvif_stats, tx_zerocopy_sent),
316 "tx_zerocopy_success",
317 offsetof(struct xenvif_stats, tx_zerocopy_success),
321 offsetof(struct xenvif_stats, tx_zerocopy_fail)
323 /* Number of packets exceeding MAX_SKB_FRAG slots. You should use
324 * a guest with the same MAX_SKB_FRAG
328 offsetof(struct xenvif_stats, tx_frag_overflow)
332 static int xenvif_get_sset_count(struct net_device *dev, int string_set)
334 switch (string_set) {
336 return ARRAY_SIZE(xenvif_stats);
342 static void xenvif_get_ethtool_stats(struct net_device *dev,
343 struct ethtool_stats *stats, u64 * data)
345 struct xenvif *vif = netdev_priv(dev);
346 unsigned int num_queues = vif->num_queues;
348 unsigned int queue_index;
350 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) {
351 unsigned long accum = 0;
352 for (queue_index = 0; queue_index < num_queues; ++queue_index) {
353 void *vif_stats = &vif->queues[queue_index].stats;
354 accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset);
360 static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
366 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
367 memcpy(data + i * ETH_GSTRING_LEN,
368 xenvif_stats[i].name, ETH_GSTRING_LEN);
373 static const struct ethtool_ops xenvif_ethtool_ops = {
374 .get_link = ethtool_op_get_link,
376 .get_sset_count = xenvif_get_sset_count,
377 .get_ethtool_stats = xenvif_get_ethtool_stats,
378 .get_strings = xenvif_get_strings,
381 static const struct net_device_ops xenvif_netdev_ops = {
382 .ndo_start_xmit = xenvif_start_xmit,
383 .ndo_get_stats = xenvif_get_stats,
384 .ndo_open = xenvif_open,
385 .ndo_stop = xenvif_close,
386 .ndo_change_mtu = xenvif_change_mtu,
387 .ndo_fix_features = xenvif_fix_features,
388 .ndo_set_mac_address = eth_mac_addr,
389 .ndo_validate_addr = eth_validate_addr,
392 struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
396 struct net_device *dev;
398 char name[IFNAMSIZ] = {};
400 snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
401 /* Allocate a netdev with the max. supported number of queues.
402 * When the guest selects the desired number, it will be updated
403 * via netif_set_real_num_*_queues().
405 dev = alloc_netdev_mq(sizeof(struct xenvif), name, NET_NAME_UNKNOWN,
406 ether_setup, xenvif_max_queues);
408 pr_warn("Could not allocate netdev for %s\n", name);
409 return ERR_PTR(-ENOMEM);
412 SET_NETDEV_DEV(dev, parent);
414 vif = netdev_priv(dev);
417 vif->handle = handle;
421 vif->disabled = false;
422 vif->drain_timeout = msecs_to_jiffies(rx_drain_timeout_msecs);
423 vif->stall_timeout = msecs_to_jiffies(rx_stall_timeout_msecs);
425 /* Start out with no queues. */
429 spin_lock_init(&vif->lock);
431 dev->netdev_ops = &xenvif_netdev_ops;
432 dev->hw_features = NETIF_F_SG |
433 NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
434 NETIF_F_TSO | NETIF_F_TSO6;
435 dev->features = dev->hw_features | NETIF_F_RXCSUM;
436 dev->ethtool_ops = &xenvif_ethtool_ops;
438 dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
441 * Initialise a dummy MAC address. We choose the numerically
442 * largest non-broadcast address to prevent the address getting
443 * stolen by an Ethernet bridge for STP purposes.
444 * (FE:FF:FF:FF:FF:FF)
446 eth_broadcast_addr(dev->dev_addr);
447 dev->dev_addr[0] &= ~0x01;
449 netif_carrier_off(dev);
451 err = register_netdev(dev);
453 netdev_warn(dev, "Could not register device: err=%d\n", err);
458 netdev_dbg(dev, "Successfully created xenvif\n");
460 __module_get(THIS_MODULE);
465 int xenvif_init_queue(struct xenvif_queue *queue)
469 queue->credit_bytes = queue->remaining_credit = ~0UL;
470 queue->credit_usec = 0UL;
471 init_timer(&queue->credit_timeout);
472 queue->credit_timeout.function = xenvif_tx_credit_callback;
473 queue->credit_window_start = get_jiffies_64();
475 queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES;
477 skb_queue_head_init(&queue->rx_queue);
478 skb_queue_head_init(&queue->tx_queue);
480 queue->pending_cons = 0;
481 queue->pending_prod = MAX_PENDING_REQS;
482 for (i = 0; i < MAX_PENDING_REQS; ++i)
483 queue->pending_ring[i] = i;
485 spin_lock_init(&queue->callback_lock);
486 spin_lock_init(&queue->response_lock);
488 /* If ballooning is disabled, this will consume real memory, so you
489 * better enable it. The long term solution would be to use just a
490 * bunch of valid page descriptors, without dependency on ballooning
492 err = gnttab_alloc_pages(MAX_PENDING_REQS,
495 netdev_err(queue->vif->dev, "Could not reserve mmap_pages\n");
499 for (i = 0; i < MAX_PENDING_REQS; i++) {
500 queue->pending_tx_info[i].callback_struct = (struct ubuf_info)
501 { .callback = xenvif_zerocopy_callback,
504 queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE;
510 void xenvif_carrier_on(struct xenvif *vif)
513 if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
514 dev_set_mtu(vif->dev, ETH_DATA_LEN);
515 netdev_update_features(vif->dev);
516 set_bit(VIF_STATUS_CONNECTED, &vif->status);
517 if (netif_running(vif->dev))
522 int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
523 unsigned long rx_ring_ref, unsigned int tx_evtchn,
524 unsigned int rx_evtchn)
526 struct task_struct *task;
529 BUG_ON(queue->tx_irq);
531 BUG_ON(queue->dealloc_task);
533 err = xenvif_map_frontend_rings(queue, tx_ring_ref, rx_ring_ref);
537 init_waitqueue_head(&queue->wq);
538 init_waitqueue_head(&queue->dealloc_wq);
539 atomic_set(&queue->inflight_packets, 0);
541 netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll,
544 if (tx_evtchn == rx_evtchn) {
545 /* feature-split-event-channels == 0 */
546 err = bind_interdomain_evtchn_to_irqhandler(
547 queue->vif->domid, tx_evtchn, xenvif_interrupt, 0,
551 queue->tx_irq = queue->rx_irq = err;
552 disable_irq(queue->tx_irq);
554 /* feature-split-event-channels == 1 */
555 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
556 "%s-tx", queue->name);
557 err = bind_interdomain_evtchn_to_irqhandler(
558 queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
559 queue->tx_irq_name, queue);
563 disable_irq(queue->tx_irq);
565 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
566 "%s-rx", queue->name);
567 err = bind_interdomain_evtchn_to_irqhandler(
568 queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
569 queue->rx_irq_name, queue);
573 disable_irq(queue->rx_irq);
576 queue->stalled = true;
578 task = kthread_create(xenvif_kthread_guest_rx,
579 (void *)queue, "%s-guest-rx", queue->name);
581 pr_warn("Could not allocate kthread for %s\n", queue->name);
586 get_task_struct(task);
588 task = kthread_create(xenvif_dealloc_kthread,
589 (void *)queue, "%s-dealloc", queue->name);
591 pr_warn("Could not allocate kthread for %s\n", queue->name);
595 queue->dealloc_task = task;
597 wake_up_process(queue->task);
598 wake_up_process(queue->dealloc_task);
603 unbind_from_irqhandler(queue->rx_irq, queue);
606 unbind_from_irqhandler(queue->tx_irq, queue);
609 xenvif_unmap_frontend_rings(queue);
611 module_put(THIS_MODULE);
615 void xenvif_carrier_off(struct xenvif *vif)
617 struct net_device *dev = vif->dev;
620 if (test_and_clear_bit(VIF_STATUS_CONNECTED, &vif->status)) {
621 netif_carrier_off(dev); /* discard queued packets */
622 if (netif_running(dev))
628 void xenvif_disconnect(struct xenvif *vif)
630 struct xenvif_queue *queue = NULL;
631 unsigned int num_queues = vif->num_queues;
632 unsigned int queue_index;
634 xenvif_carrier_off(vif);
636 for (queue_index = 0; queue_index < num_queues; ++queue_index) {
637 queue = &vif->queues[queue_index];
639 netif_napi_del(&queue->napi);
642 kthread_stop(queue->task);
643 put_task_struct(queue->task);
647 if (queue->dealloc_task) {
648 kthread_stop(queue->dealloc_task);
649 queue->dealloc_task = NULL;
653 if (queue->tx_irq == queue->rx_irq)
654 unbind_from_irqhandler(queue->tx_irq, queue);
656 unbind_from_irqhandler(queue->tx_irq, queue);
657 unbind_from_irqhandler(queue->rx_irq, queue);
662 xenvif_unmap_frontend_rings(queue);
666 /* Reverse the relevant parts of xenvif_init_queue().
667 * Used for queue teardown from xenvif_free(), and on the
668 * error handling paths in xenbus.c:connect().
670 void xenvif_deinit_queue(struct xenvif_queue *queue)
672 gnttab_free_pages(MAX_PENDING_REQS, queue->mmap_pages);
675 void xenvif_free(struct xenvif *vif)
677 struct xenvif_queue *queue = NULL;
678 unsigned int num_queues = vif->num_queues;
679 unsigned int queue_index;
681 unregister_netdev(vif->dev);
683 for (queue_index = 0; queue_index < num_queues; ++queue_index) {
684 queue = &vif->queues[queue_index];
685 xenvif_deinit_queue(queue);
692 free_netdev(vif->dev);
694 module_put(THIS_MODULE);