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 int xenvif_schedulable(struct xenvif *vif)
48 return netif_running(vif->dev) && netif_carrier_ok(vif->dev);
51 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
53 struct xenvif *vif = dev_id;
55 if (RING_HAS_UNCONSUMED_REQUESTS(&vif->tx))
56 napi_schedule(&vif->napi);
61 static int xenvif_poll(struct napi_struct *napi, int budget)
63 struct xenvif *vif = container_of(napi, struct xenvif, napi);
66 /* This vif is rogue, we pretend we've there is nothing to do
67 * for this vif to deschedule it from NAPI. But this interface
68 * will be turned off in thread context later.
70 if (unlikely(vif->disabled)) {
75 work_done = xenvif_tx_action(vif, budget);
77 if (work_done < budget) {
81 /* It is necessary to disable IRQ before calling
82 * RING_HAS_UNCONSUMED_REQUESTS. Otherwise we might
83 * lose event from the frontend.
86 * RING_HAS_UNCONSUMED_REQUESTS
87 * <frontend generates event to trigger napi_schedule>
90 * This handler is still in scheduled state so the
91 * event has no effect at all. After __napi_complete
92 * this handler is descheduled and cannot get
93 * scheduled again. We lose event in this case and the ring
94 * will be completely stalled.
97 local_irq_save(flags);
99 RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do);
101 __napi_complete(napi);
103 local_irq_restore(flags);
109 static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
111 struct xenvif *vif = dev_id;
113 xenvif_kick_thread(vif);
118 static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
120 xenvif_tx_interrupt(irq, dev_id);
121 xenvif_rx_interrupt(irq, dev_id);
126 static void xenvif_wake_queue(unsigned long data)
128 struct xenvif *vif = (struct xenvif *)data;
130 if (netif_queue_stopped(vif->dev)) {
131 netdev_err(vif->dev, "draining TX queue\n");
132 vif->rx_queue_purge = true;
133 xenvif_kick_thread(vif);
134 netif_wake_queue(vif->dev);
138 static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
140 struct xenvif *vif = netdev_priv(dev);
141 int min_slots_needed;
143 BUG_ON(skb->dev != dev);
145 /* Drop the packet if vif is not ready */
146 if (vif->task == NULL ||
147 vif->dealloc_task == NULL ||
148 !xenvif_schedulable(vif))
151 /* At best we'll need one slot for the header and one for each
154 min_slots_needed = 1 + skb_shinfo(skb)->nr_frags;
156 /* If the skb is GSO then we'll also need an extra slot for the
162 /* If the skb can't possibly fit in the remaining slots
163 * then turn off the queue to give the ring a chance to
166 if (!xenvif_rx_ring_slots_available(vif, min_slots_needed)) {
167 vif->wake_queue.function = xenvif_wake_queue;
168 vif->wake_queue.data = (unsigned long)vif;
169 xenvif_stop_queue(vif);
170 mod_timer(&vif->wake_queue,
171 jiffies + rx_drain_timeout_jiffies);
174 skb_queue_tail(&vif->rx_queue, skb);
175 xenvif_kick_thread(vif);
180 vif->dev->stats.tx_dropped++;
185 static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
187 struct xenvif *vif = netdev_priv(dev);
188 return &vif->dev->stats;
191 static void xenvif_up(struct xenvif *vif)
193 napi_enable(&vif->napi);
194 enable_irq(vif->tx_irq);
195 if (vif->tx_irq != vif->rx_irq)
196 enable_irq(vif->rx_irq);
197 xenvif_check_rx_xenvif(vif);
200 static void xenvif_down(struct xenvif *vif)
202 napi_disable(&vif->napi);
203 disable_irq(vif->tx_irq);
204 if (vif->tx_irq != vif->rx_irq)
205 disable_irq(vif->rx_irq);
206 del_timer_sync(&vif->credit_timeout);
209 static int xenvif_open(struct net_device *dev)
211 struct xenvif *vif = netdev_priv(dev);
212 if (netif_carrier_ok(dev))
214 netif_start_queue(dev);
218 static int xenvif_close(struct net_device *dev)
220 struct xenvif *vif = netdev_priv(dev);
221 if (netif_carrier_ok(dev))
223 netif_stop_queue(dev);
227 static int xenvif_change_mtu(struct net_device *dev, int mtu)
229 struct xenvif *vif = netdev_priv(dev);
230 int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN;
238 static netdev_features_t xenvif_fix_features(struct net_device *dev,
239 netdev_features_t features)
241 struct xenvif *vif = netdev_priv(dev);
244 features &= ~NETIF_F_SG;
245 if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV4))
246 features &= ~NETIF_F_TSO;
247 if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV6))
248 features &= ~NETIF_F_TSO6;
250 features &= ~NETIF_F_IP_CSUM;
252 features &= ~NETIF_F_IPV6_CSUM;
257 static const struct xenvif_stat {
258 char name[ETH_GSTRING_LEN];
262 "rx_gso_checksum_fixup",
263 offsetof(struct xenvif, rx_gso_checksum_fixup)
265 /* If (sent != success + fail), there are probably packets never
270 offsetof(struct xenvif, tx_zerocopy_sent),
273 "tx_zerocopy_success",
274 offsetof(struct xenvif, tx_zerocopy_success),
278 offsetof(struct xenvif, tx_zerocopy_fail)
280 /* Number of packets exceeding MAX_SKB_FRAG slots. You should use
281 * a guest with the same MAX_SKB_FRAG
285 offsetof(struct xenvif, tx_frag_overflow)
289 static int xenvif_get_sset_count(struct net_device *dev, int string_set)
291 switch (string_set) {
293 return ARRAY_SIZE(xenvif_stats);
299 static void xenvif_get_ethtool_stats(struct net_device *dev,
300 struct ethtool_stats *stats, u64 * data)
302 void *vif = netdev_priv(dev);
305 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
306 data[i] = *(unsigned long *)(vif + xenvif_stats[i].offset);
309 static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
315 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
316 memcpy(data + i * ETH_GSTRING_LEN,
317 xenvif_stats[i].name, ETH_GSTRING_LEN);
322 static const struct ethtool_ops xenvif_ethtool_ops = {
323 .get_link = ethtool_op_get_link,
325 .get_sset_count = xenvif_get_sset_count,
326 .get_ethtool_stats = xenvif_get_ethtool_stats,
327 .get_strings = xenvif_get_strings,
330 static const struct net_device_ops xenvif_netdev_ops = {
331 .ndo_start_xmit = xenvif_start_xmit,
332 .ndo_get_stats = xenvif_get_stats,
333 .ndo_open = xenvif_open,
334 .ndo_stop = xenvif_close,
335 .ndo_change_mtu = xenvif_change_mtu,
336 .ndo_fix_features = xenvif_fix_features,
337 .ndo_set_mac_address = eth_mac_addr,
338 .ndo_validate_addr = eth_validate_addr,
341 struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
345 struct net_device *dev;
347 char name[IFNAMSIZ] = {};
350 snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
351 dev = alloc_netdev(sizeof(struct xenvif), name, ether_setup);
353 pr_warn("Could not allocate netdev for %s\n", name);
354 return ERR_PTR(-ENOMEM);
357 SET_NETDEV_DEV(dev, parent);
359 vif = netdev_priv(dev);
361 vif->grant_copy_op = vmalloc(sizeof(struct gnttab_copy) *
363 if (vif->grant_copy_op == NULL) {
364 pr_warn("Could not allocate grant copy space for %s\n", name);
366 return ERR_PTR(-ENOMEM);
370 vif->handle = handle;
375 vif->disabled = false;
377 vif->credit_bytes = vif->remaining_credit = ~0UL;
378 vif->credit_usec = 0UL;
379 init_timer(&vif->credit_timeout);
380 vif->credit_window_start = get_jiffies_64();
382 init_timer(&vif->wake_queue);
384 dev->netdev_ops = &xenvif_netdev_ops;
385 dev->hw_features = NETIF_F_SG |
386 NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
387 NETIF_F_TSO | NETIF_F_TSO6;
388 dev->features = dev->hw_features | NETIF_F_RXCSUM;
389 SET_ETHTOOL_OPS(dev, &xenvif_ethtool_ops);
391 dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
393 skb_queue_head_init(&vif->rx_queue);
394 skb_queue_head_init(&vif->tx_queue);
396 vif->pending_cons = 0;
397 vif->pending_prod = MAX_PENDING_REQS;
398 for (i = 0; i < MAX_PENDING_REQS; i++)
399 vif->pending_ring[i] = i;
400 spin_lock_init(&vif->callback_lock);
401 spin_lock_init(&vif->response_lock);
402 /* If ballooning is disabled, this will consume real memory, so you
403 * better enable it. The long term solution would be to use just a
404 * bunch of valid page descriptors, without dependency on ballooning
406 err = alloc_xenballooned_pages(MAX_PENDING_REQS,
410 netdev_err(dev, "Could not reserve mmap_pages\n");
411 return ERR_PTR(-ENOMEM);
413 for (i = 0; i < MAX_PENDING_REQS; i++) {
414 vif->pending_tx_info[i].callback_struct = (struct ubuf_info)
415 { .callback = xenvif_zerocopy_callback,
418 vif->grant_tx_handle[i] = NETBACK_INVALID_HANDLE;
422 * Initialise a dummy MAC address. We choose the numerically
423 * largest non-broadcast address to prevent the address getting
424 * stolen by an Ethernet bridge for STP purposes.
425 * (FE:FF:FF:FF:FF:FF)
427 memset(dev->dev_addr, 0xFF, ETH_ALEN);
428 dev->dev_addr[0] &= ~0x01;
430 netif_napi_add(dev, &vif->napi, xenvif_poll, XENVIF_NAPI_WEIGHT);
432 netif_carrier_off(dev);
434 err = register_netdev(dev);
436 netdev_warn(dev, "Could not register device: err=%d\n", err);
441 netdev_dbg(dev, "Successfully created xenvif\n");
443 __module_get(THIS_MODULE);
448 int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
449 unsigned long rx_ring_ref, unsigned int tx_evtchn,
450 unsigned int rx_evtchn)
452 struct task_struct *task;
457 BUG_ON(vif->dealloc_task);
459 err = xenvif_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref);
463 init_waitqueue_head(&vif->wq);
464 init_waitqueue_head(&vif->dealloc_wq);
466 if (tx_evtchn == rx_evtchn) {
467 /* feature-split-event-channels == 0 */
468 err = bind_interdomain_evtchn_to_irqhandler(
469 vif->domid, tx_evtchn, xenvif_interrupt, 0,
470 vif->dev->name, vif);
473 vif->tx_irq = vif->rx_irq = err;
474 disable_irq(vif->tx_irq);
476 /* feature-split-event-channels == 1 */
477 snprintf(vif->tx_irq_name, sizeof(vif->tx_irq_name),
478 "%s-tx", vif->dev->name);
479 err = bind_interdomain_evtchn_to_irqhandler(
480 vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
481 vif->tx_irq_name, vif);
485 disable_irq(vif->tx_irq);
487 snprintf(vif->rx_irq_name, sizeof(vif->rx_irq_name),
488 "%s-rx", vif->dev->name);
489 err = bind_interdomain_evtchn_to_irqhandler(
490 vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
491 vif->rx_irq_name, vif);
495 disable_irq(vif->rx_irq);
498 task = kthread_create(xenvif_kthread_guest_rx,
499 (void *)vif, "%s-guest-rx", vif->dev->name);
501 pr_warn("Could not allocate kthread for %s\n", vif->dev->name);
508 task = kthread_create(xenvif_dealloc_kthread,
509 (void *)vif, "%s-dealloc", vif->dev->name);
511 pr_warn("Could not allocate kthread for %s\n", vif->dev->name);
516 vif->dealloc_task = task;
519 if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
520 dev_set_mtu(vif->dev, ETH_DATA_LEN);
521 netdev_update_features(vif->dev);
522 netif_carrier_on(vif->dev);
523 if (netif_running(vif->dev))
527 wake_up_process(vif->task);
528 wake_up_process(vif->dealloc_task);
533 unbind_from_irqhandler(vif->rx_irq, vif);
536 unbind_from_irqhandler(vif->tx_irq, vif);
539 xenvif_unmap_frontend_rings(vif);
541 module_put(THIS_MODULE);
545 void xenvif_carrier_off(struct xenvif *vif)
547 struct net_device *dev = vif->dev;
550 netif_carrier_off(dev); /* discard queued packets */
551 if (netif_running(dev))
556 void xenvif_disconnect(struct xenvif *vif)
558 if (netif_carrier_ok(vif->dev))
559 xenvif_carrier_off(vif);
562 del_timer_sync(&vif->wake_queue);
563 kthread_stop(vif->task);
567 if (vif->dealloc_task) {
568 kthread_stop(vif->dealloc_task);
569 vif->dealloc_task = NULL;
573 if (vif->tx_irq == vif->rx_irq)
574 unbind_from_irqhandler(vif->tx_irq, vif);
576 unbind_from_irqhandler(vif->tx_irq, vif);
577 unbind_from_irqhandler(vif->rx_irq, vif);
582 xenvif_unmap_frontend_rings(vif);
585 void xenvif_free(struct xenvif *vif)
587 int i, unmap_timeout = 0;
588 /* Here we want to avoid timeout messages if an skb can be legitimately
589 * stuck somewhere else. Realistically this could be an another vif's
590 * internal or QDisc queue. That another vif also has this
591 * rx_drain_timeout_msecs timeout, but the timer only ditches the
592 * internal queue. After that, the QDisc queue can put in worst case
593 * XEN_NETIF_RX_RING_SIZE / MAX_SKB_FRAGS skbs into that another vif's
594 * internal queue, so we need several rounds of such timeouts until we
595 * can be sure that no another vif should have skb's from us. We are
596 * not sending more skb's, so newly stuck packets are not interesting
599 unsigned int worst_case_skb_lifetime = (rx_drain_timeout_msecs/1000) *
600 DIV_ROUND_UP(XENVIF_QUEUE_LENGTH, (XEN_NETIF_RX_RING_SIZE / MAX_SKB_FRAGS));
602 for (i = 0; i < MAX_PENDING_REQS; ++i) {
603 if (vif->grant_tx_handle[i] != NETBACK_INVALID_HANDLE) {
605 schedule_timeout(msecs_to_jiffies(1000));
606 if (unmap_timeout > worst_case_skb_lifetime &&
609 "Page still granted! Index: %x\n",
611 /* If there are still unmapped pages, reset the loop to
612 * start checking again. We shouldn't exit here until
613 * dealloc thread and NAPI instance release all the
614 * pages. If a kernel bug causes the skbs to stall
615 * somewhere, the interface cannot be brought down
622 free_xenballooned_pages(MAX_PENDING_REQS, vif->mmap_pages);
624 netif_napi_del(&vif->napi);
626 unregister_netdev(vif->dev);
628 vfree(vif->grant_copy_op);
629 free_netdev(vif->dev);
631 module_put(THIS_MODULE);