2 * Virtual network driver for conversing with remote driver backends.
4 * Copyright (c) 2002-2005, K A Fraser
5 * Copyright (c) 2005, XenSource Ltd
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version 2
9 * as published by the Free Software Foundation; or, when distributed
10 * separately from the Linux kernel or incorporated into other
11 * software packages, subject to the following license:
13 * Permission is hereby granted, free of charge, to any person obtaining a copy
14 * of this source file (the "Software"), to deal in the Software without
15 * restriction, including without limitation the rights to use, copy, modify,
16 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
17 * and to permit persons to whom the Software is furnished to do so, subject to
18 * the following conditions:
20 * The above copyright notice and this permission notice shall be included in
21 * all copies or substantial portions of the Software.
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
28 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
32 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34 #include <linux/module.h>
35 #include <linux/kernel.h>
36 #include <linux/netdevice.h>
37 #include <linux/etherdevice.h>
38 #include <linux/skbuff.h>
39 #include <linux/ethtool.h>
40 #include <linux/if_ether.h>
42 #include <linux/udp.h>
43 #include <linux/moduleparam.h>
45 #include <linux/slab.h>
47 #include <linux/bpf.h>
48 #include <net/page_pool.h>
49 #include <linux/bpf_trace.h>
52 #include <xen/xenbus.h>
53 #include <xen/events.h>
55 #include <xen/platform_pci.h>
56 #include <xen/grant_table.h>
58 #include <xen/interface/io/netif.h>
59 #include <xen/interface/memory.h>
60 #include <xen/interface/grant_table.h>
62 /* Module parameters */
63 #define MAX_QUEUES_DEFAULT 8
64 static unsigned int xennet_max_queues;
65 module_param_named(max_queues, xennet_max_queues, uint, 0644);
66 MODULE_PARM_DESC(max_queues,
67 "Maximum number of queues per virtual interface");
69 #define XENNET_TIMEOUT (5 * HZ)
71 static const struct ethtool_ops xennet_ethtool_ops;
77 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
79 #define RX_COPY_THRESHOLD 256
81 #define GRANT_INVALID_REF 0
83 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
84 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
86 /* Minimum number of Rx slots (includes slot for GSO metadata). */
87 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
89 /* Queue name is interface name with "-qNNN" appended */
90 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
92 /* IRQ name is queue name with "-tx" or "-rx" appended */
93 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
95 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
97 struct netfront_stats {
100 struct u64_stats_sync syncp;
103 struct netfront_info;
105 struct netfront_queue {
106 unsigned int id; /* Queue ID, 0-based */
107 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
108 struct netfront_info *info;
110 struct bpf_prog __rcu *xdp_prog;
112 struct napi_struct napi;
114 /* Split event channels support, tx_* == rx_* when using
115 * single event channel.
117 unsigned int tx_evtchn, rx_evtchn;
118 unsigned int tx_irq, rx_irq;
119 /* Only used when split event channels support is enabled */
120 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
121 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
124 struct xen_netif_tx_front_ring tx;
128 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
129 * are linked from tx_skb_freelist through skb_entry.link.
131 * NB. Freelist index entries are always going to be less than
132 * PAGE_OFFSET, whereas pointers to skbs will always be equal or
133 * greater than PAGE_OFFSET: we use this property to distinguish
139 } tx_skbs[NET_TX_RING_SIZE];
140 grant_ref_t gref_tx_head;
141 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
142 struct page *grant_tx_page[NET_TX_RING_SIZE];
143 unsigned tx_skb_freelist;
145 spinlock_t rx_lock ____cacheline_aligned_in_smp;
146 struct xen_netif_rx_front_ring rx;
149 struct timer_list rx_refill_timer;
151 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
152 grant_ref_t gref_rx_head;
153 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
155 struct page_pool *page_pool;
156 struct xdp_rxq_info xdp_rxq;
159 struct netfront_info {
160 struct list_head list;
161 struct net_device *netdev;
163 struct xenbus_device *xbdev;
165 /* Multi-queue support */
166 struct netfront_queue *queues;
169 struct netfront_stats __percpu *rx_stats;
170 struct netfront_stats __percpu *tx_stats;
173 bool netback_has_xdp_headroom;
174 bool netfront_xdp_enabled;
176 atomic_t rx_gso_checksum_fixup;
179 struct netfront_rx_info {
180 struct xen_netif_rx_response rx;
181 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
184 static void skb_entry_set_link(union skb_entry *list, unsigned short id)
189 static int skb_entry_is_link(const union skb_entry *list)
191 BUILD_BUG_ON(sizeof(list->skb) != sizeof(list->link));
192 return (unsigned long)list->skb < PAGE_OFFSET;
196 * Access macros for acquiring freeing slots in tx_skbs[].
199 static void add_id_to_freelist(unsigned *head, union skb_entry *list,
202 skb_entry_set_link(&list[id], *head);
206 static unsigned short get_id_from_freelist(unsigned *head,
207 union skb_entry *list)
209 unsigned int id = *head;
210 *head = list[id].link;
214 static int xennet_rxidx(RING_IDX idx)
216 return idx & (NET_RX_RING_SIZE - 1);
219 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
222 int i = xennet_rxidx(ri);
223 struct sk_buff *skb = queue->rx_skbs[i];
224 queue->rx_skbs[i] = NULL;
228 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
231 int i = xennet_rxidx(ri);
232 grant_ref_t ref = queue->grant_rx_ref[i];
233 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
238 static const struct attribute_group xennet_dev_group;
241 static bool xennet_can_sg(struct net_device *dev)
243 return dev->features & NETIF_F_SG;
247 static void rx_refill_timeout(struct timer_list *t)
249 struct netfront_queue *queue = from_timer(queue, t, rx_refill_timer);
250 napi_schedule(&queue->napi);
253 static int netfront_tx_slot_available(struct netfront_queue *queue)
255 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
256 (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1);
259 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
261 struct net_device *dev = queue->info->netdev;
262 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
264 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
265 netfront_tx_slot_available(queue) &&
266 likely(netif_running(dev)))
267 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
271 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
276 skb = __netdev_alloc_skb(queue->info->netdev,
277 RX_COPY_THRESHOLD + NET_IP_ALIGN,
278 GFP_ATOMIC | __GFP_NOWARN);
282 page = page_pool_dev_alloc_pages(queue->page_pool);
283 if (unlikely(!page)) {
287 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
289 /* Align ip header to a 16 bytes boundary */
290 skb_reserve(skb, NET_IP_ALIGN);
291 skb->dev = queue->info->netdev;
297 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
299 RING_IDX req_prod = queue->rx.req_prod_pvt;
303 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
306 for (req_prod = queue->rx.req_prod_pvt;
307 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
313 struct xen_netif_rx_request *req;
315 skb = xennet_alloc_one_rx_buffer(queue);
321 id = xennet_rxidx(req_prod);
323 BUG_ON(queue->rx_skbs[id]);
324 queue->rx_skbs[id] = skb;
326 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
327 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
328 queue->grant_rx_ref[id] = ref;
330 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
332 req = RING_GET_REQUEST(&queue->rx, req_prod);
333 gnttab_page_grant_foreign_access_ref_one(ref,
334 queue->info->xbdev->otherend_id,
341 queue->rx.req_prod_pvt = req_prod;
343 /* Try again later if there are not enough requests or skb allocation
345 * Enough requests is quantified as the sum of newly created slots and
346 * the unconsumed slots at the backend.
348 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
350 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
354 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
356 notify_remote_via_irq(queue->rx_irq);
359 static int xennet_open(struct net_device *dev)
361 struct netfront_info *np = netdev_priv(dev);
362 unsigned int num_queues = dev->real_num_tx_queues;
364 struct netfront_queue *queue = NULL;
369 for (i = 0; i < num_queues; ++i) {
370 queue = &np->queues[i];
371 napi_enable(&queue->napi);
373 spin_lock_bh(&queue->rx_lock);
374 if (netif_carrier_ok(dev)) {
375 xennet_alloc_rx_buffers(queue);
376 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
377 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
378 napi_schedule(&queue->napi);
380 spin_unlock_bh(&queue->rx_lock);
383 netif_tx_start_all_queues(dev);
388 static void xennet_tx_buf_gc(struct netfront_queue *queue)
395 BUG_ON(!netif_carrier_ok(queue->info->netdev));
398 prod = queue->tx.sring->rsp_prod;
399 rmb(); /* Ensure we see responses up to 'rp'. */
401 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
402 struct xen_netif_tx_response *txrsp;
404 txrsp = RING_GET_RESPONSE(&queue->tx, cons);
405 if (txrsp->status == XEN_NETIF_RSP_NULL)
409 skb = queue->tx_skbs[id].skb;
410 if (unlikely(gnttab_query_foreign_access(
411 queue->grant_tx_ref[id]) != 0)) {
412 pr_alert("%s: warning -- grant still in use by backend domain\n",
416 gnttab_end_foreign_access_ref(
417 queue->grant_tx_ref[id], GNTMAP_readonly);
418 gnttab_release_grant_reference(
419 &queue->gref_tx_head, queue->grant_tx_ref[id]);
420 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
421 queue->grant_tx_page[id] = NULL;
422 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, id);
423 dev_kfree_skb_irq(skb);
426 queue->tx.rsp_cons = prod;
428 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
429 } while (more_to_do);
431 xennet_maybe_wake_tx(queue);
434 struct xennet_gnttab_make_txreq {
435 struct netfront_queue *queue;
438 struct xen_netif_tx_request *tx; /* Last request */
442 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
443 unsigned int len, void *data)
445 struct xennet_gnttab_make_txreq *info = data;
447 struct xen_netif_tx_request *tx;
449 /* convenient aliases */
450 struct page *page = info->page;
451 struct netfront_queue *queue = info->queue;
452 struct sk_buff *skb = info->skb;
454 id = get_id_from_freelist(&queue->tx_skb_freelist, queue->tx_skbs);
455 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
456 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
457 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
459 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
460 gfn, GNTMAP_readonly);
462 queue->tx_skbs[id].skb = skb;
463 queue->grant_tx_page[id] = page;
464 queue->grant_tx_ref[id] = ref;
473 info->size += tx->size;
476 static struct xen_netif_tx_request *xennet_make_first_txreq(
477 struct netfront_queue *queue, struct sk_buff *skb,
478 struct page *page, unsigned int offset, unsigned int len)
480 struct xennet_gnttab_make_txreq info = {
487 gnttab_for_one_grant(page, offset, len, xennet_tx_setup_grant, &info);
492 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
493 unsigned int len, void *data)
495 struct xennet_gnttab_make_txreq *info = data;
497 info->tx->flags |= XEN_NETTXF_more_data;
499 xennet_tx_setup_grant(gfn, offset, len, data);
502 static struct xen_netif_tx_request *xennet_make_txreqs(
503 struct netfront_queue *queue, struct xen_netif_tx_request *tx,
504 struct sk_buff *skb, struct page *page,
505 unsigned int offset, unsigned int len)
507 struct xennet_gnttab_make_txreq info = {
513 /* Skip unused frames from start of page */
514 page += offset >> PAGE_SHIFT;
515 offset &= ~PAGE_MASK;
521 gnttab_foreach_grant_in_range(page, offset, len,
522 xennet_make_one_txreq,
534 * Count how many ring slots are required to send this skb. Each frag
535 * might be a compound page.
537 static int xennet_count_skb_slots(struct sk_buff *skb)
539 int i, frags = skb_shinfo(skb)->nr_frags;
542 slots = gnttab_count_grant(offset_in_page(skb->data),
545 for (i = 0; i < frags; i++) {
546 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
547 unsigned long size = skb_frag_size(frag);
548 unsigned long offset = skb_frag_off(frag);
550 /* Skip unused frames from start of page */
551 offset &= ~PAGE_MASK;
553 slots += gnttab_count_grant(offset, size);
559 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
560 struct net_device *sb_dev)
562 unsigned int num_queues = dev->real_num_tx_queues;
566 /* First, check if there is only one queue */
567 if (num_queues == 1) {
570 hash = skb_get_hash(skb);
571 queue_idx = hash % num_queues;
577 static int xennet_xdp_xmit_one(struct net_device *dev,
578 struct netfront_queue *queue,
579 struct xdp_frame *xdpf)
581 struct netfront_info *np = netdev_priv(dev);
582 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
585 xennet_make_first_txreq(queue, NULL,
586 virt_to_page(xdpf->data),
587 offset_in_page(xdpf->data),
590 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
592 notify_remote_via_irq(queue->tx_irq);
594 u64_stats_update_begin(&tx_stats->syncp);
595 tx_stats->bytes += xdpf->len;
597 u64_stats_update_end(&tx_stats->syncp);
599 xennet_tx_buf_gc(queue);
604 static int xennet_xdp_xmit(struct net_device *dev, int n,
605 struct xdp_frame **frames, u32 flags)
607 unsigned int num_queues = dev->real_num_tx_queues;
608 struct netfront_info *np = netdev_priv(dev);
609 struct netfront_queue *queue = NULL;
610 unsigned long irq_flags;
614 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
617 queue = &np->queues[smp_processor_id() % num_queues];
619 spin_lock_irqsave(&queue->tx_lock, irq_flags);
620 for (i = 0; i < n; i++) {
621 struct xdp_frame *xdpf = frames[i];
625 if (xennet_xdp_xmit_one(dev, queue, xdpf))
629 spin_unlock_irqrestore(&queue->tx_lock, irq_flags);
635 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
637 static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
639 struct netfront_info *np = netdev_priv(dev);
640 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
641 struct xen_netif_tx_request *tx, *first_tx;
649 struct netfront_queue *queue = NULL;
650 unsigned int num_queues = dev->real_num_tx_queues;
652 struct sk_buff *nskb;
654 /* Drop the packet if no queues are set up */
657 /* Determine which queue to transmit this SKB on */
658 queue_index = skb_get_queue_mapping(skb);
659 queue = &np->queues[queue_index];
661 /* If skb->len is too big for wire format, drop skb and alert
662 * user about misconfiguration.
664 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
665 net_alert_ratelimited(
666 "xennet: skb->len = %u, too big for wire format\n",
671 slots = xennet_count_skb_slots(skb);
672 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
673 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
675 if (skb_linearize(skb))
679 page = virt_to_page(skb->data);
680 offset = offset_in_page(skb->data);
682 /* The first req should be at least ETH_HLEN size or the packet will be
683 * dropped by netback.
685 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
686 nskb = skb_copy(skb, GFP_ATOMIC);
689 dev_consume_skb_any(skb);
691 page = virt_to_page(skb->data);
692 offset = offset_in_page(skb->data);
695 len = skb_headlen(skb);
697 spin_lock_irqsave(&queue->tx_lock, flags);
699 if (unlikely(!netif_carrier_ok(dev) ||
700 (slots > 1 && !xennet_can_sg(dev)) ||
701 netif_needs_gso(skb, netif_skb_features(skb)))) {
702 spin_unlock_irqrestore(&queue->tx_lock, flags);
706 /* First request for the linear area. */
707 first_tx = tx = xennet_make_first_txreq(queue, skb,
710 if (offset == PAGE_SIZE) {
716 if (skb->ip_summed == CHECKSUM_PARTIAL)
718 tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated;
719 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
720 /* remote but checksummed. */
721 tx->flags |= XEN_NETTXF_data_validated;
723 /* Optional extra info after the first request. */
724 if (skb_shinfo(skb)->gso_size) {
725 struct xen_netif_extra_info *gso;
727 gso = (struct xen_netif_extra_info *)
728 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
730 tx->flags |= XEN_NETTXF_extra_info;
732 gso->u.gso.size = skb_shinfo(skb)->gso_size;
733 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
734 XEN_NETIF_GSO_TYPE_TCPV6 :
735 XEN_NETIF_GSO_TYPE_TCPV4;
737 gso->u.gso.features = 0;
739 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
743 /* Requests for the rest of the linear area. */
744 tx = xennet_make_txreqs(queue, tx, skb, page, offset, len);
746 /* Requests for all the frags. */
747 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
748 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
749 tx = xennet_make_txreqs(queue, tx, skb, skb_frag_page(frag),
751 skb_frag_size(frag));
754 /* First request has the packet length. */
755 first_tx->size = skb->len;
757 /* timestamp packet in software */
758 skb_tx_timestamp(skb);
760 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
762 notify_remote_via_irq(queue->tx_irq);
764 u64_stats_update_begin(&tx_stats->syncp);
765 tx_stats->bytes += skb->len;
767 u64_stats_update_end(&tx_stats->syncp);
769 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
770 xennet_tx_buf_gc(queue);
772 if (!netfront_tx_slot_available(queue))
773 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
775 spin_unlock_irqrestore(&queue->tx_lock, flags);
780 dev->stats.tx_dropped++;
781 dev_kfree_skb_any(skb);
785 static int xennet_close(struct net_device *dev)
787 struct netfront_info *np = netdev_priv(dev);
788 unsigned int num_queues = dev->real_num_tx_queues;
790 struct netfront_queue *queue;
791 netif_tx_stop_all_queues(np->netdev);
792 for (i = 0; i < num_queues; ++i) {
793 queue = &np->queues[i];
794 napi_disable(&queue->napi);
799 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
802 int new = xennet_rxidx(queue->rx.req_prod_pvt);
804 BUG_ON(queue->rx_skbs[new]);
805 queue->rx_skbs[new] = skb;
806 queue->grant_rx_ref[new] = ref;
807 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
808 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
809 queue->rx.req_prod_pvt++;
812 static int xennet_get_extras(struct netfront_queue *queue,
813 struct xen_netif_extra_info *extras,
817 struct xen_netif_extra_info *extra;
818 struct device *dev = &queue->info->netdev->dev;
819 RING_IDX cons = queue->rx.rsp_cons;
826 if (unlikely(cons + 1 == rp)) {
828 dev_warn(dev, "Missing extra info\n");
833 extra = (struct xen_netif_extra_info *)
834 RING_GET_RESPONSE(&queue->rx, ++cons);
836 if (unlikely(!extra->type ||
837 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
839 dev_warn(dev, "Invalid extra type: %d\n",
843 memcpy(&extras[extra->type - 1], extra,
847 skb = xennet_get_rx_skb(queue, cons);
848 ref = xennet_get_rx_ref(queue, cons);
849 xennet_move_rx_slot(queue, skb, ref);
850 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
852 queue->rx.rsp_cons = cons;
856 static u32 xennet_run_xdp(struct netfront_queue *queue, struct page *pdata,
857 struct xen_netif_rx_response *rx, struct bpf_prog *prog,
858 struct xdp_buff *xdp, bool *need_xdp_flush)
860 struct xdp_frame *xdpf;
861 u32 len = rx->status;
865 xdp_init_buff(xdp, XEN_PAGE_SIZE - XDP_PACKET_HEADROOM,
867 xdp_prepare_buff(xdp, page_address(pdata), XDP_PACKET_HEADROOM,
870 act = bpf_prog_run_xdp(prog, xdp);
874 xdpf = xdp_convert_buff_to_frame(xdp);
875 err = xennet_xdp_xmit(queue->info->netdev, 1, &xdpf, 0);
877 xdp_return_frame_rx_napi(xdpf);
878 else if (unlikely(err < 0))
879 trace_xdp_exception(queue->info->netdev, prog, act);
883 err = xdp_do_redirect(queue->info->netdev, xdp, prog);
884 *need_xdp_flush = true;
886 trace_xdp_exception(queue->info->netdev, prog, act);
893 trace_xdp_exception(queue->info->netdev, prog, act);
897 bpf_warn_invalid_xdp_action(act);
903 static int xennet_get_responses(struct netfront_queue *queue,
904 struct netfront_rx_info *rinfo, RING_IDX rp,
905 struct sk_buff_head *list,
906 bool *need_xdp_flush)
908 struct xen_netif_rx_response *rx = &rinfo->rx;
909 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
910 RING_IDX cons = queue->rx.rsp_cons;
911 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
912 struct xen_netif_extra_info *extras = rinfo->extras;
913 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
914 struct device *dev = &queue->info->netdev->dev;
915 struct bpf_prog *xdp_prog;
922 if (rx->flags & XEN_NETRXF_extra_info) {
923 err = xennet_get_extras(queue, extras, rp);
925 if (extras[XEN_NETIF_EXTRA_TYPE_XDP - 1].type) {
926 struct xen_netif_extra_info *xdp;
928 xdp = &extras[XEN_NETIF_EXTRA_TYPE_XDP - 1];
929 rx->offset = xdp->u.xdp.headroom;
932 cons = queue->rx.rsp_cons;
936 if (unlikely(rx->status < 0 ||
937 rx->offset + rx->status > XEN_PAGE_SIZE)) {
939 dev_warn(dev, "rx->offset: %u, size: %d\n",
940 rx->offset, rx->status);
941 xennet_move_rx_slot(queue, skb, ref);
947 * This definitely indicates a bug, either in this driver or in
948 * the backend driver. In future this should flag the bad
949 * situation to the system controller to reboot the backend.
951 if (ref == GRANT_INVALID_REF) {
953 dev_warn(dev, "Bad rx response id %d.\n",
959 ret = gnttab_end_foreign_access_ref(ref, 0);
962 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
965 xdp_prog = rcu_dereference(queue->xdp_prog);
967 if (!(rx->flags & XEN_NETRXF_more_data)) {
968 /* currently only a single page contains data */
969 verdict = xennet_run_xdp(queue,
970 skb_frag_page(&skb_shinfo(skb)->frags[0]),
971 rx, xdp_prog, &xdp, need_xdp_flush);
972 if (verdict != XDP_PASS)
981 __skb_queue_tail(list, skb);
982 if (!(rx->flags & XEN_NETRXF_more_data))
985 if (cons + slots == rp) {
987 dev_warn(dev, "Need more slots\n");
992 rx = RING_GET_RESPONSE(&queue->rx, cons + slots);
993 skb = xennet_get_rx_skb(queue, cons + slots);
994 ref = xennet_get_rx_ref(queue, cons + slots);
998 if (unlikely(slots > max)) {
1000 dev_warn(dev, "Too many slots\n");
1005 queue->rx.rsp_cons = cons + slots;
1010 static int xennet_set_skb_gso(struct sk_buff *skb,
1011 struct xen_netif_extra_info *gso)
1013 if (!gso->u.gso.size) {
1014 if (net_ratelimit())
1015 pr_warn("GSO size must not be zero\n");
1019 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
1020 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
1021 if (net_ratelimit())
1022 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
1026 skb_shinfo(skb)->gso_size = gso->u.gso.size;
1027 skb_shinfo(skb)->gso_type =
1028 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
1032 /* Header must be checked, and gso_segs computed. */
1033 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1034 skb_shinfo(skb)->gso_segs = 0;
1039 static int xennet_fill_frags(struct netfront_queue *queue,
1040 struct sk_buff *skb,
1041 struct sk_buff_head *list)
1043 RING_IDX cons = queue->rx.rsp_cons;
1044 struct sk_buff *nskb;
1046 while ((nskb = __skb_dequeue(list))) {
1047 struct xen_netif_rx_response *rx =
1048 RING_GET_RESPONSE(&queue->rx, ++cons);
1049 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
1051 if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) {
1052 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
1054 BUG_ON(pull_to < skb_headlen(skb));
1055 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
1057 if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) {
1058 queue->rx.rsp_cons = ++cons + skb_queue_len(list);
1063 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
1064 skb_frag_page(nfrag),
1065 rx->offset, rx->status, PAGE_SIZE);
1067 skb_shinfo(nskb)->nr_frags = 0;
1071 queue->rx.rsp_cons = cons;
1076 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
1078 bool recalculate_partial_csum = false;
1081 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
1082 * peers can fail to set NETRXF_csum_blank when sending a GSO
1083 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
1084 * recalculate the partial checksum.
1086 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
1087 struct netfront_info *np = netdev_priv(dev);
1088 atomic_inc(&np->rx_gso_checksum_fixup);
1089 skb->ip_summed = CHECKSUM_PARTIAL;
1090 recalculate_partial_csum = true;
1093 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
1094 if (skb->ip_summed != CHECKSUM_PARTIAL)
1097 return skb_checksum_setup(skb, recalculate_partial_csum);
1100 static int handle_incoming_queue(struct netfront_queue *queue,
1101 struct sk_buff_head *rxq)
1103 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
1104 int packets_dropped = 0;
1105 struct sk_buff *skb;
1107 while ((skb = __skb_dequeue(rxq)) != NULL) {
1108 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
1110 if (pull_to > skb_headlen(skb))
1111 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
1113 /* Ethernet work: Delayed to here as it peeks the header. */
1114 skb->protocol = eth_type_trans(skb, queue->info->netdev);
1115 skb_reset_network_header(skb);
1117 if (checksum_setup(queue->info->netdev, skb)) {
1120 queue->info->netdev->stats.rx_errors++;
1124 u64_stats_update_begin(&rx_stats->syncp);
1125 rx_stats->packets++;
1126 rx_stats->bytes += skb->len;
1127 u64_stats_update_end(&rx_stats->syncp);
1130 napi_gro_receive(&queue->napi, skb);
1133 return packets_dropped;
1136 static int xennet_poll(struct napi_struct *napi, int budget)
1138 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
1139 struct net_device *dev = queue->info->netdev;
1140 struct sk_buff *skb;
1141 struct netfront_rx_info rinfo;
1142 struct xen_netif_rx_response *rx = &rinfo.rx;
1143 struct xen_netif_extra_info *extras = rinfo.extras;
1146 struct sk_buff_head rxq;
1147 struct sk_buff_head errq;
1148 struct sk_buff_head tmpq;
1150 bool need_xdp_flush = false;
1152 spin_lock(&queue->rx_lock);
1154 skb_queue_head_init(&rxq);
1155 skb_queue_head_init(&errq);
1156 skb_queue_head_init(&tmpq);
1158 rp = queue->rx.sring->rsp_prod;
1159 rmb(); /* Ensure we see queued responses up to 'rp'. */
1161 i = queue->rx.rsp_cons;
1163 while ((i != rp) && (work_done < budget)) {
1164 memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx));
1165 memset(extras, 0, sizeof(rinfo.extras));
1167 err = xennet_get_responses(queue, &rinfo, rp, &tmpq,
1170 if (unlikely(err)) {
1172 while ((skb = __skb_dequeue(&tmpq)))
1173 __skb_queue_tail(&errq, skb);
1174 dev->stats.rx_errors++;
1175 i = queue->rx.rsp_cons;
1179 skb = __skb_dequeue(&tmpq);
1181 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1182 struct xen_netif_extra_info *gso;
1183 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1185 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1186 __skb_queue_head(&tmpq, skb);
1187 queue->rx.rsp_cons += skb_queue_len(&tmpq);
1192 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1193 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1194 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1196 skb_frag_off_set(&skb_shinfo(skb)->frags[0], rx->offset);
1197 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1198 skb->data_len = rx->status;
1199 skb->len += rx->status;
1201 if (unlikely(xennet_fill_frags(queue, skb, &tmpq)))
1204 if (rx->flags & XEN_NETRXF_csum_blank)
1205 skb->ip_summed = CHECKSUM_PARTIAL;
1206 else if (rx->flags & XEN_NETRXF_data_validated)
1207 skb->ip_summed = CHECKSUM_UNNECESSARY;
1209 __skb_queue_tail(&rxq, skb);
1211 i = ++queue->rx.rsp_cons;
1217 __skb_queue_purge(&errq);
1219 work_done -= handle_incoming_queue(queue, &rxq);
1221 xennet_alloc_rx_buffers(queue);
1223 if (work_done < budget) {
1226 napi_complete_done(napi, work_done);
1228 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1230 napi_schedule(napi);
1233 spin_unlock(&queue->rx_lock);
1238 static int xennet_change_mtu(struct net_device *dev, int mtu)
1240 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1248 static void xennet_get_stats64(struct net_device *dev,
1249 struct rtnl_link_stats64 *tot)
1251 struct netfront_info *np = netdev_priv(dev);
1254 for_each_possible_cpu(cpu) {
1255 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1256 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1257 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1261 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1262 tx_packets = tx_stats->packets;
1263 tx_bytes = tx_stats->bytes;
1264 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1267 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1268 rx_packets = rx_stats->packets;
1269 rx_bytes = rx_stats->bytes;
1270 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1272 tot->rx_packets += rx_packets;
1273 tot->tx_packets += tx_packets;
1274 tot->rx_bytes += rx_bytes;
1275 tot->tx_bytes += tx_bytes;
1278 tot->rx_errors = dev->stats.rx_errors;
1279 tot->tx_dropped = dev->stats.tx_dropped;
1282 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1284 struct sk_buff *skb;
1287 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1288 /* Skip over entries which are actually freelist references */
1289 if (skb_entry_is_link(&queue->tx_skbs[i]))
1292 skb = queue->tx_skbs[i].skb;
1293 get_page(queue->grant_tx_page[i]);
1294 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1296 (unsigned long)page_address(queue->grant_tx_page[i]));
1297 queue->grant_tx_page[i] = NULL;
1298 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1299 add_id_to_freelist(&queue->tx_skb_freelist, queue->tx_skbs, i);
1300 dev_kfree_skb_irq(skb);
1304 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1308 spin_lock_bh(&queue->rx_lock);
1310 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1311 struct sk_buff *skb;
1314 skb = queue->rx_skbs[id];
1318 ref = queue->grant_rx_ref[id];
1319 if (ref == GRANT_INVALID_REF)
1322 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1324 /* gnttab_end_foreign_access() needs a page ref until
1325 * foreign access is ended (which may be deferred).
1328 gnttab_end_foreign_access(ref, 0,
1329 (unsigned long)page_address(page));
1330 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1335 spin_unlock_bh(&queue->rx_lock);
1338 static netdev_features_t xennet_fix_features(struct net_device *dev,
1339 netdev_features_t features)
1341 struct netfront_info *np = netdev_priv(dev);
1343 if (features & NETIF_F_SG &&
1344 !xenbus_read_unsigned(np->xbdev->otherend, "feature-sg", 0))
1345 features &= ~NETIF_F_SG;
1347 if (features & NETIF_F_IPV6_CSUM &&
1348 !xenbus_read_unsigned(np->xbdev->otherend,
1349 "feature-ipv6-csum-offload", 0))
1350 features &= ~NETIF_F_IPV6_CSUM;
1352 if (features & NETIF_F_TSO &&
1353 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv4", 0))
1354 features &= ~NETIF_F_TSO;
1356 if (features & NETIF_F_TSO6 &&
1357 !xenbus_read_unsigned(np->xbdev->otherend, "feature-gso-tcpv6", 0))
1358 features &= ~NETIF_F_TSO6;
1363 static int xennet_set_features(struct net_device *dev,
1364 netdev_features_t features)
1366 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1367 netdev_info(dev, "Reducing MTU because no SG offload");
1368 dev->mtu = ETH_DATA_LEN;
1374 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1376 struct netfront_queue *queue = dev_id;
1377 unsigned long flags;
1379 spin_lock_irqsave(&queue->tx_lock, flags);
1380 xennet_tx_buf_gc(queue);
1381 spin_unlock_irqrestore(&queue->tx_lock, flags);
1386 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1388 struct netfront_queue *queue = dev_id;
1389 struct net_device *dev = queue->info->netdev;
1391 if (likely(netif_carrier_ok(dev) &&
1392 RING_HAS_UNCONSUMED_RESPONSES(&queue->rx)))
1393 napi_schedule(&queue->napi);
1398 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1400 xennet_tx_interrupt(irq, dev_id);
1401 xennet_rx_interrupt(irq, dev_id);
1405 #ifdef CONFIG_NET_POLL_CONTROLLER
1406 static void xennet_poll_controller(struct net_device *dev)
1408 /* Poll each queue */
1409 struct netfront_info *info = netdev_priv(dev);
1410 unsigned int num_queues = dev->real_num_tx_queues;
1412 for (i = 0; i < num_queues; ++i)
1413 xennet_interrupt(0, &info->queues[i]);
1417 #define NETBACK_XDP_HEADROOM_DISABLE 0
1418 #define NETBACK_XDP_HEADROOM_ENABLE 1
1420 static int talk_to_netback_xdp(struct netfront_info *np, int xdp)
1423 unsigned short headroom;
1425 headroom = xdp ? XDP_PACKET_HEADROOM : 0;
1426 err = xenbus_printf(XBT_NIL, np->xbdev->nodename,
1427 "xdp-headroom", "%hu",
1430 pr_warn("Error writing xdp-headroom\n");
1435 static int xennet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1436 struct netlink_ext_ack *extack)
1438 unsigned long max_mtu = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM;
1439 struct netfront_info *np = netdev_priv(dev);
1440 struct bpf_prog *old_prog;
1441 unsigned int i, err;
1443 if (dev->mtu > max_mtu) {
1444 netdev_warn(dev, "XDP requires MTU less than %lu\n", max_mtu);
1448 if (!np->netback_has_xdp_headroom)
1451 xenbus_switch_state(np->xbdev, XenbusStateReconfiguring);
1453 err = talk_to_netback_xdp(np, prog ? NETBACK_XDP_HEADROOM_ENABLE :
1454 NETBACK_XDP_HEADROOM_DISABLE);
1458 /* avoid the race with XDP headroom adjustment */
1459 wait_event(module_wq,
1460 xenbus_read_driver_state(np->xbdev->otherend) ==
1461 XenbusStateReconfigured);
1462 np->netfront_xdp_enabled = true;
1464 old_prog = rtnl_dereference(np->queues[0].xdp_prog);
1467 bpf_prog_add(prog, dev->real_num_tx_queues);
1469 for (i = 0; i < dev->real_num_tx_queues; ++i)
1470 rcu_assign_pointer(np->queues[i].xdp_prog, prog);
1473 for (i = 0; i < dev->real_num_tx_queues; ++i)
1474 bpf_prog_put(old_prog);
1476 xenbus_switch_state(np->xbdev, XenbusStateConnected);
1481 static int xennet_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1483 switch (xdp->command) {
1484 case XDP_SETUP_PROG:
1485 return xennet_xdp_set(dev, xdp->prog, xdp->extack);
1491 static const struct net_device_ops xennet_netdev_ops = {
1492 .ndo_open = xennet_open,
1493 .ndo_stop = xennet_close,
1494 .ndo_start_xmit = xennet_start_xmit,
1495 .ndo_change_mtu = xennet_change_mtu,
1496 .ndo_get_stats64 = xennet_get_stats64,
1497 .ndo_set_mac_address = eth_mac_addr,
1498 .ndo_validate_addr = eth_validate_addr,
1499 .ndo_fix_features = xennet_fix_features,
1500 .ndo_set_features = xennet_set_features,
1501 .ndo_select_queue = xennet_select_queue,
1502 .ndo_bpf = xennet_xdp,
1503 .ndo_xdp_xmit = xennet_xdp_xmit,
1504 #ifdef CONFIG_NET_POLL_CONTROLLER
1505 .ndo_poll_controller = xennet_poll_controller,
1509 static void xennet_free_netdev(struct net_device *netdev)
1511 struct netfront_info *np = netdev_priv(netdev);
1513 free_percpu(np->rx_stats);
1514 free_percpu(np->tx_stats);
1515 free_netdev(netdev);
1518 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1521 struct net_device *netdev;
1522 struct netfront_info *np;
1524 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1526 return ERR_PTR(-ENOMEM);
1528 np = netdev_priv(netdev);
1534 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1535 if (np->rx_stats == NULL)
1537 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1538 if (np->tx_stats == NULL)
1541 netdev->netdev_ops = &xennet_netdev_ops;
1543 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1545 netdev->hw_features = NETIF_F_SG |
1547 NETIF_F_TSO | NETIF_F_TSO6;
1550 * Assume that all hw features are available for now. This set
1551 * will be adjusted by the call to netdev_update_features() in
1552 * xennet_connect() which is the earliest point where we can
1553 * negotiate with the backend regarding supported features.
1555 netdev->features |= netdev->hw_features;
1557 netdev->ethtool_ops = &xennet_ethtool_ops;
1558 netdev->min_mtu = ETH_MIN_MTU;
1559 netdev->max_mtu = XEN_NETIF_MAX_TX_SIZE;
1560 SET_NETDEV_DEV(netdev, &dev->dev);
1562 np->netdev = netdev;
1563 np->netfront_xdp_enabled = false;
1565 netif_carrier_off(netdev);
1568 xenbus_switch_state(dev, XenbusStateInitialising);
1569 err = wait_event_timeout(module_wq,
1570 xenbus_read_driver_state(dev->otherend) !=
1571 XenbusStateClosed &&
1572 xenbus_read_driver_state(dev->otherend) !=
1573 XenbusStateUnknown, XENNET_TIMEOUT);
1579 xennet_free_netdev(netdev);
1580 return ERR_PTR(err);
1584 * Entry point to this code when a new device is created. Allocate the basic
1585 * structures and the ring buffers for communication with the backend, and
1586 * inform the backend of the appropriate details for those.
1588 static int netfront_probe(struct xenbus_device *dev,
1589 const struct xenbus_device_id *id)
1592 struct net_device *netdev;
1593 struct netfront_info *info;
1595 netdev = xennet_create_dev(dev);
1596 if (IS_ERR(netdev)) {
1597 err = PTR_ERR(netdev);
1598 xenbus_dev_fatal(dev, err, "creating netdev");
1602 info = netdev_priv(netdev);
1603 dev_set_drvdata(&dev->dev, info);
1605 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1611 static void xennet_end_access(int ref, void *page)
1613 /* This frees the page as a side-effect */
1614 if (ref != GRANT_INVALID_REF)
1615 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1618 static void xennet_disconnect_backend(struct netfront_info *info)
1621 unsigned int num_queues = info->netdev->real_num_tx_queues;
1623 netif_carrier_off(info->netdev);
1625 for (i = 0; i < num_queues && info->queues; ++i) {
1626 struct netfront_queue *queue = &info->queues[i];
1628 del_timer_sync(&queue->rx_refill_timer);
1630 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1631 unbind_from_irqhandler(queue->tx_irq, queue);
1632 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1633 unbind_from_irqhandler(queue->tx_irq, queue);
1634 unbind_from_irqhandler(queue->rx_irq, queue);
1636 queue->tx_evtchn = queue->rx_evtchn = 0;
1637 queue->tx_irq = queue->rx_irq = 0;
1639 if (netif_running(info->netdev))
1640 napi_synchronize(&queue->napi);
1642 xennet_release_tx_bufs(queue);
1643 xennet_release_rx_bufs(queue);
1644 gnttab_free_grant_references(queue->gref_tx_head);
1645 gnttab_free_grant_references(queue->gref_rx_head);
1647 /* End access and free the pages */
1648 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1649 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1651 queue->tx_ring_ref = GRANT_INVALID_REF;
1652 queue->rx_ring_ref = GRANT_INVALID_REF;
1653 queue->tx.sring = NULL;
1654 queue->rx.sring = NULL;
1656 page_pool_destroy(queue->page_pool);
1661 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1662 * driver restart. We tear down our netif structure and recreate it, but
1663 * leave the device-layer structures intact so that this is transparent to the
1664 * rest of the kernel.
1666 static int netfront_resume(struct xenbus_device *dev)
1668 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1670 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1672 xennet_disconnect_backend(info);
1676 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1678 char *s, *e, *macstr;
1681 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1683 return PTR_ERR(macstr);
1685 for (i = 0; i < ETH_ALEN; i++) {
1686 mac[i] = simple_strtoul(s, &e, 16);
1687 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1698 static int setup_netfront_single(struct netfront_queue *queue)
1702 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1706 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1708 0, queue->info->netdev->name, queue);
1711 queue->rx_evtchn = queue->tx_evtchn;
1712 queue->rx_irq = queue->tx_irq = err;
1717 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1718 queue->tx_evtchn = 0;
1723 static int setup_netfront_split(struct netfront_queue *queue)
1727 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1730 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1732 goto alloc_rx_evtchn_fail;
1734 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1735 "%s-tx", queue->name);
1736 err = bind_evtchn_to_irqhandler(queue->tx_evtchn,
1737 xennet_tx_interrupt,
1738 0, queue->tx_irq_name, queue);
1741 queue->tx_irq = err;
1743 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1744 "%s-rx", queue->name);
1745 err = bind_evtchn_to_irqhandler(queue->rx_evtchn,
1746 xennet_rx_interrupt,
1747 0, queue->rx_irq_name, queue);
1750 queue->rx_irq = err;
1755 unbind_from_irqhandler(queue->tx_irq, queue);
1758 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1759 queue->rx_evtchn = 0;
1760 alloc_rx_evtchn_fail:
1761 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1762 queue->tx_evtchn = 0;
1767 static int setup_netfront(struct xenbus_device *dev,
1768 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1770 struct xen_netif_tx_sring *txs;
1771 struct xen_netif_rx_sring *rxs;
1775 queue->tx_ring_ref = GRANT_INVALID_REF;
1776 queue->rx_ring_ref = GRANT_INVALID_REF;
1777 queue->rx.sring = NULL;
1778 queue->tx.sring = NULL;
1780 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1783 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1786 SHARED_RING_INIT(txs);
1787 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1789 err = xenbus_grant_ring(dev, txs, 1, &gref);
1791 goto grant_tx_ring_fail;
1792 queue->tx_ring_ref = gref;
1794 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1797 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1798 goto alloc_rx_ring_fail;
1800 SHARED_RING_INIT(rxs);
1801 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1803 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1805 goto grant_rx_ring_fail;
1806 queue->rx_ring_ref = gref;
1808 if (feature_split_evtchn)
1809 err = setup_netfront_split(queue);
1810 /* setup single event channel if
1811 * a) feature-split-event-channels == 0
1812 * b) feature-split-event-channels == 1 but failed to setup
1814 if (!feature_split_evtchn || err)
1815 err = setup_netfront_single(queue);
1818 goto alloc_evtchn_fail;
1822 /* If we fail to setup netfront, it is safe to just revoke access to
1823 * granted pages because backend is not accessing it at this point.
1826 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1828 free_page((unsigned long)rxs);
1830 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1832 free_page((unsigned long)txs);
1837 /* Queue-specific initialisation
1838 * This used to be done in xennet_create_dev() but must now
1841 static int xennet_init_queue(struct netfront_queue *queue)
1847 spin_lock_init(&queue->tx_lock);
1848 spin_lock_init(&queue->rx_lock);
1850 timer_setup(&queue->rx_refill_timer, rx_refill_timeout, 0);
1852 devid = strrchr(queue->info->xbdev->nodename, '/') + 1;
1853 snprintf(queue->name, sizeof(queue->name), "vif%s-q%u",
1856 /* Initialise tx_skbs as a free chain containing every entry. */
1857 queue->tx_skb_freelist = 0;
1858 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1859 skb_entry_set_link(&queue->tx_skbs[i], i+1);
1860 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1861 queue->grant_tx_page[i] = NULL;
1864 /* Clear out rx_skbs */
1865 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1866 queue->rx_skbs[i] = NULL;
1867 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1870 /* A grant for every tx ring slot */
1871 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1872 &queue->gref_tx_head) < 0) {
1873 pr_alert("can't alloc tx grant refs\n");
1878 /* A grant for every rx ring slot */
1879 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1880 &queue->gref_rx_head) < 0) {
1881 pr_alert("can't alloc rx grant refs\n");
1889 gnttab_free_grant_references(queue->gref_tx_head);
1894 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1895 struct xenbus_transaction *xbt, int write_hierarchical)
1897 /* Write the queue-specific keys into XenStore in the traditional
1898 * way for a single queue, or in a queue subkeys for multiple
1901 struct xenbus_device *dev = queue->info->xbdev;
1903 const char *message;
1907 /* Choose the correct place to write the keys */
1908 if (write_hierarchical) {
1909 pathsize = strlen(dev->nodename) + 10;
1910 path = kzalloc(pathsize, GFP_KERNEL);
1913 message = "out of memory while writing ring references";
1916 snprintf(path, pathsize, "%s/queue-%u",
1917 dev->nodename, queue->id);
1919 path = (char *)dev->nodename;
1922 /* Write ring references */
1923 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1924 queue->tx_ring_ref);
1926 message = "writing tx-ring-ref";
1930 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1931 queue->rx_ring_ref);
1933 message = "writing rx-ring-ref";
1937 /* Write event channels; taking into account both shared
1938 * and split event channel scenarios.
1940 if (queue->tx_evtchn == queue->rx_evtchn) {
1941 /* Shared event channel */
1942 err = xenbus_printf(*xbt, path,
1943 "event-channel", "%u", queue->tx_evtchn);
1945 message = "writing event-channel";
1949 /* Split event channels */
1950 err = xenbus_printf(*xbt, path,
1951 "event-channel-tx", "%u", queue->tx_evtchn);
1953 message = "writing event-channel-tx";
1957 err = xenbus_printf(*xbt, path,
1958 "event-channel-rx", "%u", queue->rx_evtchn);
1960 message = "writing event-channel-rx";
1965 if (write_hierarchical)
1970 if (write_hierarchical)
1972 xenbus_dev_fatal(dev, err, "%s", message);
1976 static void xennet_destroy_queues(struct netfront_info *info)
1980 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1981 struct netfront_queue *queue = &info->queues[i];
1983 if (netif_running(info->netdev))
1984 napi_disable(&queue->napi);
1985 netif_napi_del(&queue->napi);
1988 kfree(info->queues);
1989 info->queues = NULL;
1994 static int xennet_create_page_pool(struct netfront_queue *queue)
1997 struct page_pool_params pp_params = {
2000 .pool_size = NET_RX_RING_SIZE,
2001 .nid = NUMA_NO_NODE,
2002 .dev = &queue->info->netdev->dev,
2003 .offset = XDP_PACKET_HEADROOM,
2004 .max_len = XEN_PAGE_SIZE - XDP_PACKET_HEADROOM,
2007 queue->page_pool = page_pool_create(&pp_params);
2008 if (IS_ERR(queue->page_pool)) {
2009 err = PTR_ERR(queue->page_pool);
2010 queue->page_pool = NULL;
2014 err = xdp_rxq_info_reg(&queue->xdp_rxq, queue->info->netdev,
2017 netdev_err(queue->info->netdev, "xdp_rxq_info_reg failed\n");
2021 err = xdp_rxq_info_reg_mem_model(&queue->xdp_rxq,
2022 MEM_TYPE_PAGE_POOL, queue->page_pool);
2024 netdev_err(queue->info->netdev, "xdp_rxq_info_reg_mem_model failed\n");
2025 goto err_unregister_rxq;
2030 xdp_rxq_info_unreg(&queue->xdp_rxq);
2032 page_pool_destroy(queue->page_pool);
2033 queue->page_pool = NULL;
2037 static int xennet_create_queues(struct netfront_info *info,
2038 unsigned int *num_queues)
2043 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
2048 for (i = 0; i < *num_queues; i++) {
2049 struct netfront_queue *queue = &info->queues[i];
2054 ret = xennet_init_queue(queue);
2056 dev_warn(&info->xbdev->dev,
2057 "only created %d queues\n", i);
2062 /* use page pool recycling instead of buddy allocator */
2063 ret = xennet_create_page_pool(queue);
2065 dev_err(&info->xbdev->dev, "can't allocate page pool\n");
2070 netif_napi_add(queue->info->netdev, &queue->napi,
2072 if (netif_running(info->netdev))
2073 napi_enable(&queue->napi);
2076 netif_set_real_num_tx_queues(info->netdev, *num_queues);
2078 if (*num_queues == 0) {
2079 dev_err(&info->xbdev->dev, "no queues\n");
2085 /* Common code used when first setting up, and when resuming. */
2086 static int talk_to_netback(struct xenbus_device *dev,
2087 struct netfront_info *info)
2089 const char *message;
2090 struct xenbus_transaction xbt;
2092 unsigned int feature_split_evtchn;
2094 unsigned int max_queues = 0;
2095 struct netfront_queue *queue = NULL;
2096 unsigned int num_queues = 1;
2098 info->netdev->irq = 0;
2100 /* Check if backend supports multiple queues */
2101 max_queues = xenbus_read_unsigned(info->xbdev->otherend,
2102 "multi-queue-max-queues", 1);
2103 num_queues = min(max_queues, xennet_max_queues);
2105 /* Check feature-split-event-channels */
2106 feature_split_evtchn = xenbus_read_unsigned(info->xbdev->otherend,
2107 "feature-split-event-channels", 0);
2109 /* Read mac addr. */
2110 err = xen_net_read_mac(dev, info->netdev->dev_addr);
2112 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
2116 info->netback_has_xdp_headroom = xenbus_read_unsigned(info->xbdev->otherend,
2117 "feature-xdp-headroom", 0);
2118 if (info->netback_has_xdp_headroom) {
2119 /* set the current xen-netfront xdp state */
2120 err = talk_to_netback_xdp(info, info->netfront_xdp_enabled ?
2121 NETBACK_XDP_HEADROOM_ENABLE :
2122 NETBACK_XDP_HEADROOM_DISABLE);
2129 xennet_destroy_queues(info);
2131 err = xennet_create_queues(info, &num_queues);
2133 xenbus_dev_fatal(dev, err, "creating queues");
2134 kfree(info->queues);
2135 info->queues = NULL;
2140 /* Create shared ring, alloc event channel -- for each queue */
2141 for (i = 0; i < num_queues; ++i) {
2142 queue = &info->queues[i];
2143 err = setup_netfront(dev, queue, feature_split_evtchn);
2149 err = xenbus_transaction_start(&xbt);
2151 xenbus_dev_fatal(dev, err, "starting transaction");
2155 if (xenbus_exists(XBT_NIL,
2156 info->xbdev->otherend, "multi-queue-max-queues")) {
2157 /* Write the number of queues */
2158 err = xenbus_printf(xbt, dev->nodename,
2159 "multi-queue-num-queues", "%u", num_queues);
2161 message = "writing multi-queue-num-queues";
2162 goto abort_transaction_no_dev_fatal;
2166 if (num_queues == 1) {
2167 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
2169 goto abort_transaction_no_dev_fatal;
2171 /* Write the keys for each queue */
2172 for (i = 0; i < num_queues; ++i) {
2173 queue = &info->queues[i];
2174 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
2176 goto abort_transaction_no_dev_fatal;
2180 /* The remaining keys are not queue-specific */
2181 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
2184 message = "writing request-rx-copy";
2185 goto abort_transaction;
2188 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
2190 message = "writing feature-rx-notify";
2191 goto abort_transaction;
2194 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
2196 message = "writing feature-sg";
2197 goto abort_transaction;
2200 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
2202 message = "writing feature-gso-tcpv4";
2203 goto abort_transaction;
2206 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
2208 message = "writing feature-gso-tcpv6";
2209 goto abort_transaction;
2212 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
2215 message = "writing feature-ipv6-csum-offload";
2216 goto abort_transaction;
2219 err = xenbus_transaction_end(xbt, 0);
2223 xenbus_dev_fatal(dev, err, "completing transaction");
2230 xenbus_dev_fatal(dev, err, "%s", message);
2231 abort_transaction_no_dev_fatal:
2232 xenbus_transaction_end(xbt, 1);
2234 xennet_disconnect_backend(info);
2236 xennet_destroy_queues(info);
2240 device_unregister(&dev->dev);
2244 static int xennet_connect(struct net_device *dev)
2246 struct netfront_info *np = netdev_priv(dev);
2247 unsigned int num_queues = 0;
2250 struct netfront_queue *queue = NULL;
2252 if (!xenbus_read_unsigned(np->xbdev->otherend, "feature-rx-copy", 0)) {
2254 "backend does not support copying receive path\n");
2258 err = talk_to_netback(np->xbdev, np);
2261 if (np->netback_has_xdp_headroom)
2262 pr_info("backend supports XDP headroom\n");
2264 /* talk_to_netback() sets the correct number of queues */
2265 num_queues = dev->real_num_tx_queues;
2267 if (dev->reg_state == NETREG_UNINITIALIZED) {
2268 err = register_netdev(dev);
2270 pr_warn("%s: register_netdev err=%d\n", __func__, err);
2271 device_unregister(&np->xbdev->dev);
2277 netdev_update_features(dev);
2281 * All public and private state should now be sane. Get
2282 * ready to start sending and receiving packets and give the driver
2283 * domain a kick because we've probably just requeued some
2286 netif_carrier_on(np->netdev);
2287 for (j = 0; j < num_queues; ++j) {
2288 queue = &np->queues[j];
2290 notify_remote_via_irq(queue->tx_irq);
2291 if (queue->tx_irq != queue->rx_irq)
2292 notify_remote_via_irq(queue->rx_irq);
2294 spin_lock_irq(&queue->tx_lock);
2295 xennet_tx_buf_gc(queue);
2296 spin_unlock_irq(&queue->tx_lock);
2298 spin_lock_bh(&queue->rx_lock);
2299 xennet_alloc_rx_buffers(queue);
2300 spin_unlock_bh(&queue->rx_lock);
2307 * Callback received when the backend's state changes.
2309 static void netback_changed(struct xenbus_device *dev,
2310 enum xenbus_state backend_state)
2312 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2313 struct net_device *netdev = np->netdev;
2315 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2317 wake_up_all(&module_wq);
2319 switch (backend_state) {
2320 case XenbusStateInitialising:
2321 case XenbusStateInitialised:
2322 case XenbusStateReconfiguring:
2323 case XenbusStateReconfigured:
2324 case XenbusStateUnknown:
2327 case XenbusStateInitWait:
2328 if (dev->state != XenbusStateInitialising)
2330 if (xennet_connect(netdev) != 0)
2332 xenbus_switch_state(dev, XenbusStateConnected);
2335 case XenbusStateConnected:
2336 netdev_notify_peers(netdev);
2339 case XenbusStateClosed:
2340 if (dev->state == XenbusStateClosed)
2342 fallthrough; /* Missed the backend's CLOSING state */
2343 case XenbusStateClosing:
2344 xenbus_frontend_closed(dev);
2349 static const struct xennet_stat {
2350 char name[ETH_GSTRING_LEN];
2352 } xennet_stats[] = {
2354 "rx_gso_checksum_fixup",
2355 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2359 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2361 switch (string_set) {
2363 return ARRAY_SIZE(xennet_stats);
2369 static void xennet_get_ethtool_stats(struct net_device *dev,
2370 struct ethtool_stats *stats, u64 * data)
2372 void *np = netdev_priv(dev);
2375 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2376 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2379 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2383 switch (stringset) {
2385 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2386 memcpy(data + i * ETH_GSTRING_LEN,
2387 xennet_stats[i].name, ETH_GSTRING_LEN);
2392 static const struct ethtool_ops xennet_ethtool_ops =
2394 .get_link = ethtool_op_get_link,
2396 .get_sset_count = xennet_get_sset_count,
2397 .get_ethtool_stats = xennet_get_ethtool_stats,
2398 .get_strings = xennet_get_strings,
2399 .get_ts_info = ethtool_op_get_ts_info,
2403 static ssize_t show_rxbuf(struct device *dev,
2404 struct device_attribute *attr, char *buf)
2406 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2409 static ssize_t store_rxbuf(struct device *dev,
2410 struct device_attribute *attr,
2411 const char *buf, size_t len)
2415 if (!capable(CAP_NET_ADMIN))
2418 simple_strtoul(buf, &endp, 0);
2422 /* rxbuf_min and rxbuf_max are no longer configurable. */
2427 static DEVICE_ATTR(rxbuf_min, 0644, show_rxbuf, store_rxbuf);
2428 static DEVICE_ATTR(rxbuf_max, 0644, show_rxbuf, store_rxbuf);
2429 static DEVICE_ATTR(rxbuf_cur, 0444, show_rxbuf, NULL);
2431 static struct attribute *xennet_dev_attrs[] = {
2432 &dev_attr_rxbuf_min.attr,
2433 &dev_attr_rxbuf_max.attr,
2434 &dev_attr_rxbuf_cur.attr,
2438 static const struct attribute_group xennet_dev_group = {
2439 .attrs = xennet_dev_attrs
2441 #endif /* CONFIG_SYSFS */
2443 static void xennet_bus_close(struct xenbus_device *dev)
2447 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2450 xenbus_switch_state(dev, XenbusStateClosing);
2451 ret = wait_event_timeout(module_wq,
2452 xenbus_read_driver_state(dev->otherend) ==
2453 XenbusStateClosing ||
2454 xenbus_read_driver_state(dev->otherend) ==
2455 XenbusStateClosed ||
2456 xenbus_read_driver_state(dev->otherend) ==
2461 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2465 xenbus_switch_state(dev, XenbusStateClosed);
2466 ret = wait_event_timeout(module_wq,
2467 xenbus_read_driver_state(dev->otherend) ==
2468 XenbusStateClosed ||
2469 xenbus_read_driver_state(dev->otherend) ==
2475 static int xennet_remove(struct xenbus_device *dev)
2477 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2479 xennet_bus_close(dev);
2480 xennet_disconnect_backend(info);
2482 if (info->netdev->reg_state == NETREG_REGISTERED)
2483 unregister_netdev(info->netdev);
2487 xennet_destroy_queues(info);
2490 xennet_free_netdev(info->netdev);
2495 static const struct xenbus_device_id netfront_ids[] = {
2500 static struct xenbus_driver netfront_driver = {
2501 .ids = netfront_ids,
2502 .probe = netfront_probe,
2503 .remove = xennet_remove,
2504 .resume = netfront_resume,
2505 .otherend_changed = netback_changed,
2508 static int __init netif_init(void)
2513 if (!xen_has_pv_nic_devices())
2516 pr_info("Initialising Xen virtual ethernet driver\n");
2518 /* Allow as many queues as there are CPUs inut max. 8 if user has not
2519 * specified a value.
2521 if (xennet_max_queues == 0)
2522 xennet_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
2525 return xenbus_register_frontend(&netfront_driver);
2527 module_init(netif_init);
2530 static void __exit netif_exit(void)
2532 xenbus_unregister_driver(&netfront_driver);
2534 module_exit(netif_exit);
2536 MODULE_DESCRIPTION("Xen virtual network device frontend");
2537 MODULE_LICENSE("GPL");
2538 MODULE_ALIAS("xen:vif");
2539 MODULE_ALIAS("xennet");