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>
49 #include <xen/xenbus.h>
50 #include <xen/events.h>
52 #include <xen/platform_pci.h>
53 #include <xen/grant_table.h>
55 #include <xen/interface/io/netif.h>
56 #include <xen/interface/memory.h>
57 #include <xen/interface/grant_table.h>
59 /* Module parameters */
60 static unsigned int xennet_max_queues;
61 module_param_named(max_queues, xennet_max_queues, uint, 0644);
62 MODULE_PARM_DESC(max_queues,
63 "Maximum number of queues per virtual interface");
65 #define XENNET_TIMEOUT (5 * HZ)
67 static const struct ethtool_ops xennet_ethtool_ops;
73 #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb))
75 #define RX_COPY_THRESHOLD 256
77 #define GRANT_INVALID_REF 0
79 #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, XEN_PAGE_SIZE)
80 #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, XEN_PAGE_SIZE)
82 /* Minimum number of Rx slots (includes slot for GSO metadata). */
83 #define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
85 /* Queue name is interface name with "-qNNN" appended */
86 #define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
88 /* IRQ name is queue name with "-tx" or "-rx" appended */
89 #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3)
91 static DECLARE_WAIT_QUEUE_HEAD(module_wq);
93 struct netfront_stats {
96 struct u64_stats_sync syncp;
101 struct netfront_queue {
102 unsigned int id; /* Queue ID, 0-based */
103 char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
104 struct netfront_info *info;
106 struct napi_struct napi;
108 /* Split event channels support, tx_* == rx_* when using
109 * single event channel.
111 unsigned int tx_evtchn, rx_evtchn;
112 unsigned int tx_irq, rx_irq;
113 /* Only used when split event channels support is enabled */
114 char tx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-tx */
115 char rx_irq_name[IRQ_NAME_SIZE]; /* DEVNAME-qN-rx */
118 struct xen_netif_tx_front_ring tx;
122 * {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
123 * are linked from tx_skb_freelist through tx_link.
125 struct sk_buff *tx_skbs[NET_TX_RING_SIZE];
126 unsigned short tx_link[NET_TX_RING_SIZE];
127 #define TX_LINK_NONE 0xffff
128 #define TX_PENDING 0xfffe
129 grant_ref_t gref_tx_head;
130 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
131 struct page *grant_tx_page[NET_TX_RING_SIZE];
132 unsigned tx_skb_freelist;
133 unsigned int tx_pend_queue;
135 spinlock_t rx_lock ____cacheline_aligned_in_smp;
136 struct xen_netif_rx_front_ring rx;
139 struct timer_list rx_refill_timer;
141 struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
142 grant_ref_t gref_rx_head;
143 grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
145 unsigned int rx_rsp_unconsumed;
146 spinlock_t rx_cons_lock;
149 struct netfront_info {
150 struct list_head list;
151 struct net_device *netdev;
153 struct xenbus_device *xbdev;
155 /* Multi-queue support */
156 struct netfront_queue *queues;
159 struct netfront_stats __percpu *rx_stats;
160 struct netfront_stats __percpu *tx_stats;
162 /* Is device behaving sane? */
165 atomic_t rx_gso_checksum_fixup;
168 struct netfront_rx_info {
169 struct xen_netif_rx_response rx;
170 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
174 * Access macros for acquiring freeing slots in tx_skbs[].
177 static void add_id_to_list(unsigned *head, unsigned short *list,
184 static unsigned short get_id_from_list(unsigned *head, unsigned short *list)
186 unsigned int id = *head;
188 if (id != TX_LINK_NONE) {
190 list[id] = TX_LINK_NONE;
195 static int xennet_rxidx(RING_IDX idx)
197 return idx & (NET_RX_RING_SIZE - 1);
200 static struct sk_buff *xennet_get_rx_skb(struct netfront_queue *queue,
203 int i = xennet_rxidx(ri);
204 struct sk_buff *skb = queue->rx_skbs[i];
205 queue->rx_skbs[i] = NULL;
209 static grant_ref_t xennet_get_rx_ref(struct netfront_queue *queue,
212 int i = xennet_rxidx(ri);
213 grant_ref_t ref = queue->grant_rx_ref[i];
214 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
219 static const struct attribute_group xennet_dev_group;
222 static bool xennet_can_sg(struct net_device *dev)
224 return dev->features & NETIF_F_SG;
228 static void rx_refill_timeout(unsigned long data)
230 struct netfront_queue *queue = (struct netfront_queue *)data;
231 napi_schedule(&queue->napi);
234 static int netfront_tx_slot_available(struct netfront_queue *queue)
236 return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
237 (NET_TX_RING_SIZE - XEN_NETIF_NR_SLOTS_MIN - 1);
240 static void xennet_maybe_wake_tx(struct netfront_queue *queue)
242 struct net_device *dev = queue->info->netdev;
243 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, queue->id);
245 if (unlikely(netif_tx_queue_stopped(dev_queue)) &&
246 netfront_tx_slot_available(queue) &&
247 likely(netif_running(dev)))
248 netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
252 static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
257 skb = __netdev_alloc_skb(queue->info->netdev,
258 RX_COPY_THRESHOLD + NET_IP_ALIGN,
259 GFP_ATOMIC | __GFP_NOWARN);
263 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
268 skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
270 /* Align ip header to a 16 bytes boundary */
271 skb_reserve(skb, NET_IP_ALIGN);
272 skb->dev = queue->info->netdev;
278 static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
280 RING_IDX req_prod = queue->rx.req_prod_pvt;
284 if (unlikely(!netif_carrier_ok(queue->info->netdev)))
287 for (req_prod = queue->rx.req_prod_pvt;
288 req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
294 struct xen_netif_rx_request *req;
296 skb = xennet_alloc_one_rx_buffer(queue);
302 id = xennet_rxidx(req_prod);
304 BUG_ON(queue->rx_skbs[id]);
305 queue->rx_skbs[id] = skb;
307 ref = gnttab_claim_grant_reference(&queue->gref_rx_head);
308 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
309 queue->grant_rx_ref[id] = ref;
311 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
313 req = RING_GET_REQUEST(&queue->rx, req_prod);
314 gnttab_page_grant_foreign_access_ref_one(ref,
315 queue->info->xbdev->otherend_id,
322 queue->rx.req_prod_pvt = req_prod;
324 /* Try again later if there are not enough requests or skb allocation
326 * Enough requests is quantified as the sum of newly created slots and
327 * the unconsumed slots at the backend.
329 if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN ||
331 mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
335 wmb(); /* barrier so backend seens requests */
337 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
339 notify_remote_via_irq(queue->rx_irq);
342 static int xennet_open(struct net_device *dev)
344 struct netfront_info *np = netdev_priv(dev);
345 unsigned int num_queues = dev->real_num_tx_queues;
347 struct netfront_queue *queue = NULL;
349 if (!np->queues || np->broken)
352 for (i = 0; i < num_queues; ++i) {
353 queue = &np->queues[i];
354 napi_enable(&queue->napi);
356 spin_lock_bh(&queue->rx_lock);
357 if (netif_carrier_ok(dev)) {
358 xennet_alloc_rx_buffers(queue);
359 queue->rx.sring->rsp_event = queue->rx.rsp_cons + 1;
360 if (RING_HAS_UNCONSUMED_RESPONSES(&queue->rx))
361 napi_schedule(&queue->napi);
363 spin_unlock_bh(&queue->rx_lock);
366 netif_tx_start_all_queues(dev);
371 static bool xennet_tx_buf_gc(struct netfront_queue *queue)
377 bool work_done = false;
378 const struct device *dev = &queue->info->netdev->dev;
380 BUG_ON(!netif_carrier_ok(queue->info->netdev));
383 prod = queue->tx.sring->rsp_prod;
384 if (RING_RESPONSE_PROD_OVERFLOW(&queue->tx, prod)) {
385 dev_alert(dev, "Illegal number of responses %u\n",
386 prod - queue->tx.rsp_cons);
389 rmb(); /* Ensure we see responses up to 'rp'. */
391 for (cons = queue->tx.rsp_cons; cons != prod; cons++) {
392 struct xen_netif_tx_response txrsp;
396 RING_COPY_RESPONSE(&queue->tx, cons, &txrsp);
397 if (txrsp.status == XEN_NETIF_RSP_NULL)
401 if (id >= RING_SIZE(&queue->tx)) {
403 "Response has incorrect id (%u)\n",
407 if (queue->tx_link[id] != TX_PENDING) {
409 "Response for inactive request\n");
413 queue->tx_link[id] = TX_LINK_NONE;
414 skb = queue->tx_skbs[id];
415 queue->tx_skbs[id] = NULL;
416 if (unlikely(gnttab_query_foreign_access(
417 queue->grant_tx_ref[id]) != 0)) {
419 "Grant still in use by backend domain\n");
422 gnttab_end_foreign_access_ref(
423 queue->grant_tx_ref[id], GNTMAP_readonly);
424 gnttab_release_grant_reference(
425 &queue->gref_tx_head, queue->grant_tx_ref[id]);
426 queue->grant_tx_ref[id] = GRANT_INVALID_REF;
427 queue->grant_tx_page[id] = NULL;
428 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, id);
429 dev_kfree_skb_irq(skb);
432 queue->tx.rsp_cons = prod;
434 RING_FINAL_CHECK_FOR_RESPONSES(&queue->tx, more_to_do);
435 } while (more_to_do);
437 xennet_maybe_wake_tx(queue);
442 queue->info->broken = true;
443 dev_alert(dev, "Disabled for further use\n");
448 struct xennet_gnttab_make_txreq {
449 struct netfront_queue *queue;
452 struct xen_netif_tx_request *tx; /* Last request on ring page */
453 struct xen_netif_tx_request tx_local; /* Last request local copy*/
457 static void xennet_tx_setup_grant(unsigned long gfn, unsigned int offset,
458 unsigned int len, void *data)
460 struct xennet_gnttab_make_txreq *info = data;
462 struct xen_netif_tx_request *tx;
464 /* convenient aliases */
465 struct page *page = info->page;
466 struct netfront_queue *queue = info->queue;
467 struct sk_buff *skb = info->skb;
469 id = get_id_from_list(&queue->tx_skb_freelist, queue->tx_link);
470 tx = RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
471 ref = gnttab_claim_grant_reference(&queue->gref_tx_head);
472 WARN_ON_ONCE(IS_ERR_VALUE((unsigned long)(int)ref));
474 gnttab_grant_foreign_access_ref(ref, queue->info->xbdev->otherend_id,
475 gfn, GNTMAP_readonly);
477 queue->tx_skbs[id] = skb;
478 queue->grant_tx_page[id] = page;
479 queue->grant_tx_ref[id] = ref;
481 info->tx_local.id = id;
482 info->tx_local.gref = ref;
483 info->tx_local.offset = offset;
484 info->tx_local.size = len;
485 info->tx_local.flags = 0;
487 *tx = info->tx_local;
490 * Put the request in the pending queue, it will be set to be pending
491 * when the producer index is about to be raised.
493 add_id_to_list(&queue->tx_pend_queue, queue->tx_link, id);
496 info->size += info->tx_local.size;
499 static struct xen_netif_tx_request *xennet_make_first_txreq(
500 struct xennet_gnttab_make_txreq *info,
501 unsigned int offset, unsigned int len)
505 gnttab_for_one_grant(info->page, offset, len, xennet_tx_setup_grant, info);
510 static void xennet_make_one_txreq(unsigned long gfn, unsigned int offset,
511 unsigned int len, void *data)
513 struct xennet_gnttab_make_txreq *info = data;
515 info->tx->flags |= XEN_NETTXF_more_data;
517 xennet_tx_setup_grant(gfn, offset, len, data);
520 static void xennet_make_txreqs(
521 struct xennet_gnttab_make_txreq *info,
523 unsigned int offset, unsigned int len)
525 /* Skip unused frames from start of page */
526 page += offset >> PAGE_SHIFT;
527 offset &= ~PAGE_MASK;
533 gnttab_foreach_grant_in_range(page, offset, len,
534 xennet_make_one_txreq,
544 * Count how many ring slots are required to send this skb. Each frag
545 * might be a compound page.
547 static int xennet_count_skb_slots(struct sk_buff *skb)
549 int i, frags = skb_shinfo(skb)->nr_frags;
552 slots = gnttab_count_grant(offset_in_page(skb->data),
555 for (i = 0; i < frags; i++) {
556 skb_frag_t *frag = skb_shinfo(skb)->frags + i;
557 unsigned long size = skb_frag_size(frag);
558 unsigned long offset = frag->page_offset;
560 /* Skip unused frames from start of page */
561 offset &= ~PAGE_MASK;
563 slots += gnttab_count_grant(offset, size);
569 static u16 xennet_select_queue(struct net_device *dev, struct sk_buff *skb,
570 void *accel_priv, select_queue_fallback_t fallback)
572 unsigned int num_queues = dev->real_num_tx_queues;
576 /* First, check if there is only one queue */
577 if (num_queues == 1) {
580 hash = skb_get_hash(skb);
581 queue_idx = hash % num_queues;
587 static void xennet_mark_tx_pending(struct netfront_queue *queue)
591 while ((i = get_id_from_list(&queue->tx_pend_queue, queue->tx_link)) !=
593 queue->tx_link[i] = TX_PENDING;
596 #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1)
598 static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev)
600 struct netfront_info *np = netdev_priv(dev);
601 struct netfront_stats *tx_stats = this_cpu_ptr(np->tx_stats);
602 struct xen_netif_tx_request *first_tx;
610 struct netfront_queue *queue = NULL;
611 struct xennet_gnttab_make_txreq info = { };
612 unsigned int num_queues = dev->real_num_tx_queues;
614 struct sk_buff *nskb;
616 /* Drop the packet if no queues are set up */
619 if (unlikely(np->broken))
621 /* Determine which queue to transmit this SKB on */
622 queue_index = skb_get_queue_mapping(skb);
623 queue = &np->queues[queue_index];
625 /* If skb->len is too big for wire format, drop skb and alert
626 * user about misconfiguration.
628 if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) {
629 net_alert_ratelimited(
630 "xennet: skb->len = %u, too big for wire format\n",
635 slots = xennet_count_skb_slots(skb);
636 if (unlikely(slots > MAX_XEN_SKB_FRAGS + 1)) {
637 net_dbg_ratelimited("xennet: skb rides the rocket: %d slots, %d bytes\n",
639 if (skb_linearize(skb))
643 page = virt_to_page(skb->data);
644 offset = offset_in_page(skb->data);
646 /* The first req should be at least ETH_HLEN size or the packet will be
647 * dropped by netback.
649 if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) {
650 nskb = skb_copy(skb, GFP_ATOMIC);
653 dev_kfree_skb_any(skb);
655 page = virt_to_page(skb->data);
656 offset = offset_in_page(skb->data);
659 len = skb_headlen(skb);
661 spin_lock_irqsave(&queue->tx_lock, flags);
663 if (unlikely(!netif_carrier_ok(dev) ||
664 (slots > 1 && !xennet_can_sg(dev)) ||
665 netif_needs_gso(skb, netif_skb_features(skb)))) {
666 spin_unlock_irqrestore(&queue->tx_lock, flags);
670 /* First request for the linear area. */
674 first_tx = xennet_make_first_txreq(&info, offset, len);
675 offset += info.tx_local.size;
676 if (offset == PAGE_SIZE) {
680 len -= info.tx_local.size;
682 if (skb->ip_summed == CHECKSUM_PARTIAL)
684 first_tx->flags |= XEN_NETTXF_csum_blank |
685 XEN_NETTXF_data_validated;
686 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
687 /* remote but checksummed. */
688 first_tx->flags |= XEN_NETTXF_data_validated;
690 /* Optional extra info after the first request. */
691 if (skb_shinfo(skb)->gso_size) {
692 struct xen_netif_extra_info *gso;
694 gso = (struct xen_netif_extra_info *)
695 RING_GET_REQUEST(&queue->tx, queue->tx.req_prod_pvt++);
697 first_tx->flags |= XEN_NETTXF_extra_info;
699 gso->u.gso.size = skb_shinfo(skb)->gso_size;
700 gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
701 XEN_NETIF_GSO_TYPE_TCPV6 :
702 XEN_NETIF_GSO_TYPE_TCPV4;
704 gso->u.gso.features = 0;
706 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
710 /* Requests for the rest of the linear area. */
711 xennet_make_txreqs(&info, page, offset, len);
713 /* Requests for all the frags. */
714 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
715 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
716 xennet_make_txreqs(&info, skb_frag_page(frag),
718 skb_frag_size(frag));
721 /* First request has the packet length. */
722 first_tx->size = skb->len;
724 xennet_mark_tx_pending(queue);
726 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->tx, notify);
728 notify_remote_via_irq(queue->tx_irq);
730 u64_stats_update_begin(&tx_stats->syncp);
731 tx_stats->bytes += skb->len;
733 u64_stats_update_end(&tx_stats->syncp);
735 /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */
736 xennet_tx_buf_gc(queue);
738 if (!netfront_tx_slot_available(queue))
739 netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
741 spin_unlock_irqrestore(&queue->tx_lock, flags);
746 dev->stats.tx_dropped++;
747 dev_kfree_skb_any(skb);
751 static int xennet_close(struct net_device *dev)
753 struct netfront_info *np = netdev_priv(dev);
754 unsigned int num_queues = dev->real_num_tx_queues;
756 struct netfront_queue *queue;
757 netif_tx_stop_all_queues(np->netdev);
758 for (i = 0; i < num_queues; ++i) {
759 queue = &np->queues[i];
760 napi_disable(&queue->napi);
765 static void xennet_set_rx_rsp_cons(struct netfront_queue *queue, RING_IDX val)
769 spin_lock_irqsave(&queue->rx_cons_lock, flags);
770 queue->rx.rsp_cons = val;
771 queue->rx_rsp_unconsumed = RING_HAS_UNCONSUMED_RESPONSES(&queue->rx);
772 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
775 static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb,
778 int new = xennet_rxidx(queue->rx.req_prod_pvt);
780 BUG_ON(queue->rx_skbs[new]);
781 queue->rx_skbs[new] = skb;
782 queue->grant_rx_ref[new] = ref;
783 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->id = new;
784 RING_GET_REQUEST(&queue->rx, queue->rx.req_prod_pvt)->gref = ref;
785 queue->rx.req_prod_pvt++;
788 static int xennet_get_extras(struct netfront_queue *queue,
789 struct xen_netif_extra_info *extras,
793 struct xen_netif_extra_info extra;
794 struct device *dev = &queue->info->netdev->dev;
795 RING_IDX cons = queue->rx.rsp_cons;
802 if (unlikely(cons + 1 == rp)) {
804 dev_warn(dev, "Missing extra info\n");
809 RING_COPY_RESPONSE(&queue->rx, ++cons, &extra);
811 if (unlikely(!extra.type ||
812 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
814 dev_warn(dev, "Invalid extra type: %d\n",
818 extras[extra.type - 1] = extra;
821 skb = xennet_get_rx_skb(queue, cons);
822 ref = xennet_get_rx_ref(queue, cons);
823 xennet_move_rx_slot(queue, skb, ref);
824 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
826 xennet_set_rx_rsp_cons(queue, cons);
830 static int xennet_get_responses(struct netfront_queue *queue,
831 struct netfront_rx_info *rinfo, RING_IDX rp,
832 struct sk_buff_head *list)
834 struct xen_netif_rx_response *rx = &rinfo->rx, rx_local;
835 struct xen_netif_extra_info *extras = rinfo->extras;
836 struct device *dev = &queue->info->netdev->dev;
837 RING_IDX cons = queue->rx.rsp_cons;
838 struct sk_buff *skb = xennet_get_rx_skb(queue, cons);
839 grant_ref_t ref = xennet_get_rx_ref(queue, cons);
840 int max = XEN_NETIF_NR_SLOTS_MIN + (rx->status <= RX_COPY_THRESHOLD);
845 if (rx->flags & XEN_NETRXF_extra_info) {
846 err = xennet_get_extras(queue, extras, rp);
847 cons = queue->rx.rsp_cons;
851 if (unlikely(rx->status < 0 ||
852 rx->offset + rx->status > XEN_PAGE_SIZE)) {
854 dev_warn(dev, "rx->offset: %u, size: %d\n",
855 rx->offset, rx->status);
856 xennet_move_rx_slot(queue, skb, ref);
862 * This definitely indicates a bug, either in this driver or in
863 * the backend driver. In future this should flag the bad
864 * situation to the system controller to reboot the backend.
866 if (ref == GRANT_INVALID_REF) {
868 dev_warn(dev, "Bad rx response id %d.\n",
874 ret = gnttab_end_foreign_access_ref(ref, 0);
877 gnttab_release_grant_reference(&queue->gref_rx_head, ref);
879 __skb_queue_tail(list, skb);
882 if (!(rx->flags & XEN_NETRXF_more_data))
885 if (cons + slots == rp) {
887 dev_warn(dev, "Need more slots\n");
892 RING_COPY_RESPONSE(&queue->rx, cons + slots, &rx_local);
894 skb = xennet_get_rx_skb(queue, cons + slots);
895 ref = xennet_get_rx_ref(queue, cons + slots);
899 if (unlikely(slots > max)) {
901 dev_warn(dev, "Too many slots\n");
906 xennet_set_rx_rsp_cons(queue, cons + slots);
911 static int xennet_set_skb_gso(struct sk_buff *skb,
912 struct xen_netif_extra_info *gso)
914 if (!gso->u.gso.size) {
916 pr_warn("GSO size must not be zero\n");
920 if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
921 gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
923 pr_warn("Bad GSO type %d\n", gso->u.gso.type);
927 skb_shinfo(skb)->gso_size = gso->u.gso.size;
928 skb_shinfo(skb)->gso_type =
929 (gso->u.gso.type == XEN_NETIF_GSO_TYPE_TCPV4) ?
933 /* Header must be checked, and gso_segs computed. */
934 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
935 skb_shinfo(skb)->gso_segs = 0;
940 static int xennet_fill_frags(struct netfront_queue *queue,
942 struct sk_buff_head *list)
944 RING_IDX cons = queue->rx.rsp_cons;
945 struct sk_buff *nskb;
947 while ((nskb = __skb_dequeue(list))) {
948 struct xen_netif_rx_response rx;
949 skb_frag_t *nfrag = &skb_shinfo(nskb)->frags[0];
951 RING_COPY_RESPONSE(&queue->rx, ++cons, &rx);
953 if (skb_shinfo(skb)->nr_frags == MAX_SKB_FRAGS) {
954 unsigned int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
956 BUG_ON(pull_to < skb_headlen(skb));
957 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
959 if (unlikely(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS)) {
960 xennet_set_rx_rsp_cons(queue,
961 ++cons + skb_queue_len(list));
966 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
967 skb_frag_page(nfrag),
968 rx.offset, rx.status, PAGE_SIZE);
970 skb_shinfo(nskb)->nr_frags = 0;
974 xennet_set_rx_rsp_cons(queue, cons);
979 static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
981 bool recalculate_partial_csum = false;
984 * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
985 * peers can fail to set NETRXF_csum_blank when sending a GSO
986 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
987 * recalculate the partial checksum.
989 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
990 struct netfront_info *np = netdev_priv(dev);
991 atomic_inc(&np->rx_gso_checksum_fixup);
992 skb->ip_summed = CHECKSUM_PARTIAL;
993 recalculate_partial_csum = true;
996 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
997 if (skb->ip_summed != CHECKSUM_PARTIAL)
1000 return skb_checksum_setup(skb, recalculate_partial_csum);
1003 static int handle_incoming_queue(struct netfront_queue *queue,
1004 struct sk_buff_head *rxq)
1006 struct netfront_stats *rx_stats = this_cpu_ptr(queue->info->rx_stats);
1007 int packets_dropped = 0;
1008 struct sk_buff *skb;
1010 while ((skb = __skb_dequeue(rxq)) != NULL) {
1011 int pull_to = NETFRONT_SKB_CB(skb)->pull_to;
1013 if (pull_to > skb_headlen(skb))
1014 __pskb_pull_tail(skb, pull_to - skb_headlen(skb));
1016 /* Ethernet work: Delayed to here as it peeks the header. */
1017 skb->protocol = eth_type_trans(skb, queue->info->netdev);
1018 skb_reset_network_header(skb);
1020 if (checksum_setup(queue->info->netdev, skb)) {
1023 queue->info->netdev->stats.rx_errors++;
1027 u64_stats_update_begin(&rx_stats->syncp);
1028 rx_stats->packets++;
1029 rx_stats->bytes += skb->len;
1030 u64_stats_update_end(&rx_stats->syncp);
1033 napi_gro_receive(&queue->napi, skb);
1036 return packets_dropped;
1039 static int xennet_poll(struct napi_struct *napi, int budget)
1041 struct netfront_queue *queue = container_of(napi, struct netfront_queue, napi);
1042 struct net_device *dev = queue->info->netdev;
1043 struct sk_buff *skb;
1044 struct netfront_rx_info rinfo;
1045 struct xen_netif_rx_response *rx = &rinfo.rx;
1046 struct xen_netif_extra_info *extras = rinfo.extras;
1049 struct sk_buff_head rxq;
1050 struct sk_buff_head errq;
1051 struct sk_buff_head tmpq;
1054 spin_lock(&queue->rx_lock);
1056 skb_queue_head_init(&rxq);
1057 skb_queue_head_init(&errq);
1058 skb_queue_head_init(&tmpq);
1060 rp = queue->rx.sring->rsp_prod;
1061 if (RING_RESPONSE_PROD_OVERFLOW(&queue->rx, rp)) {
1062 dev_alert(&dev->dev, "Illegal number of responses %u\n",
1063 rp - queue->rx.rsp_cons);
1064 queue->info->broken = true;
1065 spin_unlock(&queue->rx_lock);
1068 rmb(); /* Ensure we see queued responses up to 'rp'. */
1070 i = queue->rx.rsp_cons;
1072 while ((i != rp) && (work_done < budget)) {
1073 RING_COPY_RESPONSE(&queue->rx, i, rx);
1074 memset(extras, 0, sizeof(rinfo.extras));
1076 err = xennet_get_responses(queue, &rinfo, rp, &tmpq);
1078 if (unlikely(err)) {
1080 while ((skb = __skb_dequeue(&tmpq)))
1081 __skb_queue_tail(&errq, skb);
1082 dev->stats.rx_errors++;
1083 i = queue->rx.rsp_cons;
1087 skb = __skb_dequeue(&tmpq);
1089 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1090 struct xen_netif_extra_info *gso;
1091 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1093 if (unlikely(xennet_set_skb_gso(skb, gso))) {
1094 __skb_queue_head(&tmpq, skb);
1095 xennet_set_rx_rsp_cons(queue,
1096 queue->rx.rsp_cons +
1097 skb_queue_len(&tmpq));
1102 NETFRONT_SKB_CB(skb)->pull_to = rx->status;
1103 if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD)
1104 NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD;
1106 skb_shinfo(skb)->frags[0].page_offset = rx->offset;
1107 skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status);
1108 skb->data_len = rx->status;
1109 skb->len += rx->status;
1111 if (unlikely(xennet_fill_frags(queue, skb, &tmpq)))
1114 if (rx->flags & XEN_NETRXF_csum_blank)
1115 skb->ip_summed = CHECKSUM_PARTIAL;
1116 else if (rx->flags & XEN_NETRXF_data_validated)
1117 skb->ip_summed = CHECKSUM_UNNECESSARY;
1119 __skb_queue_tail(&rxq, skb);
1121 i = queue->rx.rsp_cons + 1;
1122 xennet_set_rx_rsp_cons(queue, i);
1126 __skb_queue_purge(&errq);
1128 work_done -= handle_incoming_queue(queue, &rxq);
1130 xennet_alloc_rx_buffers(queue);
1132 if (work_done < budget) {
1135 napi_complete(napi);
1137 RING_FINAL_CHECK_FOR_RESPONSES(&queue->rx, more_to_do);
1139 napi_schedule(napi);
1142 spin_unlock(&queue->rx_lock);
1147 static int xennet_change_mtu(struct net_device *dev, int mtu)
1149 int max = xennet_can_sg(dev) ? XEN_NETIF_MAX_TX_SIZE : ETH_DATA_LEN;
1157 static struct rtnl_link_stats64 *xennet_get_stats64(struct net_device *dev,
1158 struct rtnl_link_stats64 *tot)
1160 struct netfront_info *np = netdev_priv(dev);
1163 for_each_possible_cpu(cpu) {
1164 struct netfront_stats *rx_stats = per_cpu_ptr(np->rx_stats, cpu);
1165 struct netfront_stats *tx_stats = per_cpu_ptr(np->tx_stats, cpu);
1166 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
1170 start = u64_stats_fetch_begin_irq(&tx_stats->syncp);
1171 tx_packets = tx_stats->packets;
1172 tx_bytes = tx_stats->bytes;
1173 } while (u64_stats_fetch_retry_irq(&tx_stats->syncp, start));
1176 start = u64_stats_fetch_begin_irq(&rx_stats->syncp);
1177 rx_packets = rx_stats->packets;
1178 rx_bytes = rx_stats->bytes;
1179 } while (u64_stats_fetch_retry_irq(&rx_stats->syncp, start));
1181 tot->rx_packets += rx_packets;
1182 tot->tx_packets += tx_packets;
1183 tot->rx_bytes += rx_bytes;
1184 tot->tx_bytes += tx_bytes;
1187 tot->rx_errors = dev->stats.rx_errors;
1188 tot->tx_dropped = dev->stats.tx_dropped;
1193 static void xennet_release_tx_bufs(struct netfront_queue *queue)
1195 struct sk_buff *skb;
1198 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1199 /* Skip over entries which are actually freelist references */
1200 if (!queue->tx_skbs[i])
1203 skb = queue->tx_skbs[i];
1204 queue->tx_skbs[i] = NULL;
1205 get_page(queue->grant_tx_page[i]);
1206 gnttab_end_foreign_access(queue->grant_tx_ref[i],
1208 (unsigned long)page_address(queue->grant_tx_page[i]));
1209 queue->grant_tx_page[i] = NULL;
1210 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1211 add_id_to_list(&queue->tx_skb_freelist, queue->tx_link, i);
1212 dev_kfree_skb_irq(skb);
1216 static void xennet_release_rx_bufs(struct netfront_queue *queue)
1220 spin_lock_bh(&queue->rx_lock);
1222 for (id = 0; id < NET_RX_RING_SIZE; id++) {
1223 struct sk_buff *skb;
1226 skb = queue->rx_skbs[id];
1230 ref = queue->grant_rx_ref[id];
1231 if (ref == GRANT_INVALID_REF)
1234 page = skb_frag_page(&skb_shinfo(skb)->frags[0]);
1236 /* gnttab_end_foreign_access() needs a page ref until
1237 * foreign access is ended (which may be deferred).
1240 gnttab_end_foreign_access(ref, 0,
1241 (unsigned long)page_address(page));
1242 queue->grant_rx_ref[id] = GRANT_INVALID_REF;
1247 spin_unlock_bh(&queue->rx_lock);
1250 static netdev_features_t xennet_fix_features(struct net_device *dev,
1251 netdev_features_t features)
1253 struct netfront_info *np = netdev_priv(dev);
1256 if (features & NETIF_F_SG) {
1257 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend, "feature-sg",
1262 features &= ~NETIF_F_SG;
1265 if (features & NETIF_F_IPV6_CSUM) {
1266 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1267 "feature-ipv6-csum-offload", "%d", &val) < 0)
1271 features &= ~NETIF_F_IPV6_CSUM;
1274 if (features & NETIF_F_TSO) {
1275 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1276 "feature-gso-tcpv4", "%d", &val) < 0)
1280 features &= ~NETIF_F_TSO;
1283 if (features & NETIF_F_TSO6) {
1284 if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
1285 "feature-gso-tcpv6", "%d", &val) < 0)
1289 features &= ~NETIF_F_TSO6;
1295 static int xennet_set_features(struct net_device *dev,
1296 netdev_features_t features)
1298 if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN) {
1299 netdev_info(dev, "Reducing MTU because no SG offload");
1300 dev->mtu = ETH_DATA_LEN;
1306 static bool xennet_handle_tx(struct netfront_queue *queue, unsigned int *eoi)
1308 unsigned long flags;
1310 if (unlikely(queue->info->broken))
1313 spin_lock_irqsave(&queue->tx_lock, flags);
1314 if (xennet_tx_buf_gc(queue))
1316 spin_unlock_irqrestore(&queue->tx_lock, flags);
1321 static irqreturn_t xennet_tx_interrupt(int irq, void *dev_id)
1323 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1325 if (likely(xennet_handle_tx(dev_id, &eoiflag)))
1326 xen_irq_lateeoi(irq, eoiflag);
1331 static bool xennet_handle_rx(struct netfront_queue *queue, unsigned int *eoi)
1333 unsigned int work_queued;
1334 unsigned long flags;
1336 if (unlikely(queue->info->broken))
1339 spin_lock_irqsave(&queue->rx_cons_lock, flags);
1340 work_queued = RING_HAS_UNCONSUMED_RESPONSES(&queue->rx);
1341 if (work_queued > queue->rx_rsp_unconsumed) {
1342 queue->rx_rsp_unconsumed = work_queued;
1344 } else if (unlikely(work_queued < queue->rx_rsp_unconsumed)) {
1345 const struct device *dev = &queue->info->netdev->dev;
1347 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
1348 dev_alert(dev, "RX producer index going backwards\n");
1349 dev_alert(dev, "Disabled for further use\n");
1350 queue->info->broken = true;
1353 spin_unlock_irqrestore(&queue->rx_cons_lock, flags);
1355 if (likely(netif_carrier_ok(queue->info->netdev) && work_queued))
1356 napi_schedule(&queue->napi);
1361 static irqreturn_t xennet_rx_interrupt(int irq, void *dev_id)
1363 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1365 if (likely(xennet_handle_rx(dev_id, &eoiflag)))
1366 xen_irq_lateeoi(irq, eoiflag);
1371 static irqreturn_t xennet_interrupt(int irq, void *dev_id)
1373 unsigned int eoiflag = XEN_EOI_FLAG_SPURIOUS;
1375 if (xennet_handle_tx(dev_id, &eoiflag) &&
1376 xennet_handle_rx(dev_id, &eoiflag))
1377 xen_irq_lateeoi(irq, eoiflag);
1382 #ifdef CONFIG_NET_POLL_CONTROLLER
1383 static void xennet_poll_controller(struct net_device *dev)
1385 /* Poll each queue */
1386 struct netfront_info *info = netdev_priv(dev);
1387 unsigned int num_queues = dev->real_num_tx_queues;
1393 for (i = 0; i < num_queues; ++i)
1394 xennet_interrupt(0, &info->queues[i]);
1398 static const struct net_device_ops xennet_netdev_ops = {
1399 .ndo_open = xennet_open,
1400 .ndo_stop = xennet_close,
1401 .ndo_start_xmit = xennet_start_xmit,
1402 .ndo_change_mtu = xennet_change_mtu,
1403 .ndo_get_stats64 = xennet_get_stats64,
1404 .ndo_set_mac_address = eth_mac_addr,
1405 .ndo_validate_addr = eth_validate_addr,
1406 .ndo_fix_features = xennet_fix_features,
1407 .ndo_set_features = xennet_set_features,
1408 .ndo_select_queue = xennet_select_queue,
1409 #ifdef CONFIG_NET_POLL_CONTROLLER
1410 .ndo_poll_controller = xennet_poll_controller,
1414 static void xennet_free_netdev(struct net_device *netdev)
1416 struct netfront_info *np = netdev_priv(netdev);
1418 free_percpu(np->rx_stats);
1419 free_percpu(np->tx_stats);
1420 free_netdev(netdev);
1423 static struct net_device *xennet_create_dev(struct xenbus_device *dev)
1426 struct net_device *netdev;
1427 struct netfront_info *np;
1429 netdev = alloc_etherdev_mq(sizeof(struct netfront_info), xennet_max_queues);
1431 return ERR_PTR(-ENOMEM);
1433 np = netdev_priv(netdev);
1439 np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1440 if (np->rx_stats == NULL)
1442 np->tx_stats = netdev_alloc_pcpu_stats(struct netfront_stats);
1443 if (np->tx_stats == NULL)
1446 netdev->netdev_ops = &xennet_netdev_ops;
1448 netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
1450 netdev->hw_features = NETIF_F_SG |
1452 NETIF_F_TSO | NETIF_F_TSO6;
1455 * Assume that all hw features are available for now. This set
1456 * will be adjusted by the call to netdev_update_features() in
1457 * xennet_connect() which is the earliest point where we can
1458 * negotiate with the backend regarding supported features.
1460 netdev->features |= netdev->hw_features;
1462 netdev->ethtool_ops = &xennet_ethtool_ops;
1463 SET_NETDEV_DEV(netdev, &dev->dev);
1465 np->netdev = netdev;
1467 netif_carrier_off(netdev);
1470 xenbus_switch_state(dev, XenbusStateInitialising);
1471 err = wait_event_timeout(module_wq,
1472 xenbus_read_driver_state(dev->otherend) !=
1473 XenbusStateClosed &&
1474 xenbus_read_driver_state(dev->otherend) !=
1475 XenbusStateUnknown, XENNET_TIMEOUT);
1481 xennet_free_netdev(netdev);
1482 return ERR_PTR(err);
1486 * Entry point to this code when a new device is created. Allocate the basic
1487 * structures and the ring buffers for communication with the backend, and
1488 * inform the backend of the appropriate details for those.
1490 static int netfront_probe(struct xenbus_device *dev,
1491 const struct xenbus_device_id *id)
1494 struct net_device *netdev;
1495 struct netfront_info *info;
1497 netdev = xennet_create_dev(dev);
1498 if (IS_ERR(netdev)) {
1499 err = PTR_ERR(netdev);
1500 xenbus_dev_fatal(dev, err, "creating netdev");
1504 info = netdev_priv(netdev);
1505 dev_set_drvdata(&dev->dev, info);
1507 info->netdev->sysfs_groups[0] = &xennet_dev_group;
1513 static void xennet_end_access(int ref, void *page)
1515 /* This frees the page as a side-effect */
1516 if (ref != GRANT_INVALID_REF)
1517 gnttab_end_foreign_access(ref, 0, (unsigned long)page);
1520 static void xennet_disconnect_backend(struct netfront_info *info)
1523 unsigned int num_queues = info->netdev->real_num_tx_queues;
1525 netif_carrier_off(info->netdev);
1527 for (i = 0; i < num_queues && info->queues; ++i) {
1528 struct netfront_queue *queue = &info->queues[i];
1530 del_timer_sync(&queue->rx_refill_timer);
1532 if (queue->tx_irq && (queue->tx_irq == queue->rx_irq))
1533 unbind_from_irqhandler(queue->tx_irq, queue);
1534 if (queue->tx_irq && (queue->tx_irq != queue->rx_irq)) {
1535 unbind_from_irqhandler(queue->tx_irq, queue);
1536 unbind_from_irqhandler(queue->rx_irq, queue);
1538 queue->tx_evtchn = queue->rx_evtchn = 0;
1539 queue->tx_irq = queue->rx_irq = 0;
1541 if (netif_running(info->netdev))
1542 napi_synchronize(&queue->napi);
1544 xennet_release_tx_bufs(queue);
1545 xennet_release_rx_bufs(queue);
1546 gnttab_free_grant_references(queue->gref_tx_head);
1547 gnttab_free_grant_references(queue->gref_rx_head);
1549 /* End access and free the pages */
1550 xennet_end_access(queue->tx_ring_ref, queue->tx.sring);
1551 xennet_end_access(queue->rx_ring_ref, queue->rx.sring);
1553 queue->tx_ring_ref = GRANT_INVALID_REF;
1554 queue->rx_ring_ref = GRANT_INVALID_REF;
1555 queue->tx.sring = NULL;
1556 queue->rx.sring = NULL;
1561 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1562 * driver restart. We tear down our netif structure and recreate it, but
1563 * leave the device-layer structures intact so that this is transparent to the
1564 * rest of the kernel.
1566 static int netfront_resume(struct xenbus_device *dev)
1568 struct netfront_info *info = dev_get_drvdata(&dev->dev);
1570 dev_dbg(&dev->dev, "%s\n", dev->nodename);
1572 netif_tx_lock_bh(info->netdev);
1573 netif_device_detach(info->netdev);
1574 netif_tx_unlock_bh(info->netdev);
1576 xennet_disconnect_backend(info);
1580 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
1582 char *s, *e, *macstr;
1585 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
1587 return PTR_ERR(macstr);
1589 for (i = 0; i < ETH_ALEN; i++) {
1590 mac[i] = simple_strtoul(s, &e, 16);
1591 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
1602 static int setup_netfront_single(struct netfront_queue *queue)
1606 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1610 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn,
1611 xennet_interrupt, 0,
1612 queue->info->netdev->name,
1616 queue->rx_evtchn = queue->tx_evtchn;
1617 queue->rx_irq = queue->tx_irq = err;
1622 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1623 queue->tx_evtchn = 0;
1628 static int setup_netfront_split(struct netfront_queue *queue)
1632 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->tx_evtchn);
1635 err = xenbus_alloc_evtchn(queue->info->xbdev, &queue->rx_evtchn);
1637 goto alloc_rx_evtchn_fail;
1639 snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
1640 "%s-tx", queue->name);
1641 err = bind_evtchn_to_irqhandler_lateeoi(queue->tx_evtchn,
1642 xennet_tx_interrupt, 0,
1643 queue->tx_irq_name, queue);
1646 queue->tx_irq = err;
1648 snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
1649 "%s-rx", queue->name);
1650 err = bind_evtchn_to_irqhandler_lateeoi(queue->rx_evtchn,
1651 xennet_rx_interrupt, 0,
1652 queue->rx_irq_name, queue);
1655 queue->rx_irq = err;
1660 unbind_from_irqhandler(queue->tx_irq, queue);
1663 xenbus_free_evtchn(queue->info->xbdev, queue->rx_evtchn);
1664 queue->rx_evtchn = 0;
1665 alloc_rx_evtchn_fail:
1666 xenbus_free_evtchn(queue->info->xbdev, queue->tx_evtchn);
1667 queue->tx_evtchn = 0;
1672 static int setup_netfront(struct xenbus_device *dev,
1673 struct netfront_queue *queue, unsigned int feature_split_evtchn)
1675 struct xen_netif_tx_sring *txs;
1676 struct xen_netif_rx_sring *rxs;
1680 queue->tx_ring_ref = GRANT_INVALID_REF;
1681 queue->rx_ring_ref = GRANT_INVALID_REF;
1682 queue->rx.sring = NULL;
1683 queue->tx.sring = NULL;
1685 txs = (struct xen_netif_tx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1688 xenbus_dev_fatal(dev, err, "allocating tx ring page");
1691 SHARED_RING_INIT(txs);
1692 FRONT_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1694 err = xenbus_grant_ring(dev, txs, 1, &gref);
1696 goto grant_tx_ring_fail;
1697 queue->tx_ring_ref = gref;
1699 rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
1702 xenbus_dev_fatal(dev, err, "allocating rx ring page");
1703 goto alloc_rx_ring_fail;
1705 SHARED_RING_INIT(rxs);
1706 FRONT_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1708 err = xenbus_grant_ring(dev, rxs, 1, &gref);
1710 goto grant_rx_ring_fail;
1711 queue->rx_ring_ref = gref;
1713 if (feature_split_evtchn)
1714 err = setup_netfront_split(queue);
1715 /* setup single event channel if
1716 * a) feature-split-event-channels == 0
1717 * b) feature-split-event-channels == 1 but failed to setup
1719 if (!feature_split_evtchn || (feature_split_evtchn && err))
1720 err = setup_netfront_single(queue);
1723 goto alloc_evtchn_fail;
1727 /* If we fail to setup netfront, it is safe to just revoke access to
1728 * granted pages because backend is not accessing it at this point.
1731 gnttab_end_foreign_access_ref(queue->rx_ring_ref, 0);
1733 free_page((unsigned long)rxs);
1735 gnttab_end_foreign_access_ref(queue->tx_ring_ref, 0);
1737 free_page((unsigned long)txs);
1742 /* Queue-specific initialisation
1743 * This used to be done in xennet_create_dev() but must now
1746 static int xennet_init_queue(struct netfront_queue *queue)
1752 spin_lock_init(&queue->tx_lock);
1753 spin_lock_init(&queue->rx_lock);
1754 spin_lock_init(&queue->rx_cons_lock);
1756 setup_timer(&queue->rx_refill_timer, rx_refill_timeout,
1757 (unsigned long)queue);
1759 devid = strrchr(queue->info->xbdev->nodename, '/') + 1;
1760 snprintf(queue->name, sizeof(queue->name), "vif%s-q%u",
1763 /* Initialise tx_skb_freelist as a free chain containing every entry. */
1764 queue->tx_skb_freelist = 0;
1765 queue->tx_pend_queue = TX_LINK_NONE;
1766 for (i = 0; i < NET_TX_RING_SIZE; i++) {
1767 queue->tx_link[i] = i + 1;
1768 queue->grant_tx_ref[i] = GRANT_INVALID_REF;
1769 queue->grant_tx_page[i] = NULL;
1771 queue->tx_link[NET_TX_RING_SIZE - 1] = TX_LINK_NONE;
1773 /* Clear out rx_skbs */
1774 for (i = 0; i < NET_RX_RING_SIZE; i++) {
1775 queue->rx_skbs[i] = NULL;
1776 queue->grant_rx_ref[i] = GRANT_INVALID_REF;
1779 /* A grant for every tx ring slot */
1780 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1781 &queue->gref_tx_head) < 0) {
1782 pr_alert("can't alloc tx grant refs\n");
1787 /* A grant for every rx ring slot */
1788 if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
1789 &queue->gref_rx_head) < 0) {
1790 pr_alert("can't alloc rx grant refs\n");
1798 gnttab_free_grant_references(queue->gref_tx_head);
1803 static int write_queue_xenstore_keys(struct netfront_queue *queue,
1804 struct xenbus_transaction *xbt, int write_hierarchical)
1806 /* Write the queue-specific keys into XenStore in the traditional
1807 * way for a single queue, or in a queue subkeys for multiple
1810 struct xenbus_device *dev = queue->info->xbdev;
1812 const char *message;
1816 /* Choose the correct place to write the keys */
1817 if (write_hierarchical) {
1818 pathsize = strlen(dev->nodename) + 10;
1819 path = kzalloc(pathsize, GFP_KERNEL);
1822 message = "out of memory while writing ring references";
1825 snprintf(path, pathsize, "%s/queue-%u",
1826 dev->nodename, queue->id);
1828 path = (char *)dev->nodename;
1831 /* Write ring references */
1832 err = xenbus_printf(*xbt, path, "tx-ring-ref", "%u",
1833 queue->tx_ring_ref);
1835 message = "writing tx-ring-ref";
1839 err = xenbus_printf(*xbt, path, "rx-ring-ref", "%u",
1840 queue->rx_ring_ref);
1842 message = "writing rx-ring-ref";
1846 /* Write event channels; taking into account both shared
1847 * and split event channel scenarios.
1849 if (queue->tx_evtchn == queue->rx_evtchn) {
1850 /* Shared event channel */
1851 err = xenbus_printf(*xbt, path,
1852 "event-channel", "%u", queue->tx_evtchn);
1854 message = "writing event-channel";
1858 /* Split event channels */
1859 err = xenbus_printf(*xbt, path,
1860 "event-channel-tx", "%u", queue->tx_evtchn);
1862 message = "writing event-channel-tx";
1866 err = xenbus_printf(*xbt, path,
1867 "event-channel-rx", "%u", queue->rx_evtchn);
1869 message = "writing event-channel-rx";
1874 if (write_hierarchical)
1879 if (write_hierarchical)
1881 xenbus_dev_fatal(dev, err, "%s", message);
1885 static void xennet_destroy_queues(struct netfront_info *info)
1889 for (i = 0; i < info->netdev->real_num_tx_queues; i++) {
1890 struct netfront_queue *queue = &info->queues[i];
1892 if (netif_running(info->netdev))
1893 napi_disable(&queue->napi);
1894 netif_napi_del(&queue->napi);
1897 kfree(info->queues);
1898 info->queues = NULL;
1901 static int xennet_create_queues(struct netfront_info *info,
1902 unsigned int *num_queues)
1907 info->queues = kcalloc(*num_queues, sizeof(struct netfront_queue),
1912 for (i = 0; i < *num_queues; i++) {
1913 struct netfront_queue *queue = &info->queues[i];
1918 ret = xennet_init_queue(queue);
1920 dev_warn(&info->xbdev->dev,
1921 "only created %d queues\n", i);
1926 netif_napi_add(queue->info->netdev, &queue->napi,
1928 if (netif_running(info->netdev))
1929 napi_enable(&queue->napi);
1932 netif_set_real_num_tx_queues(info->netdev, *num_queues);
1934 if (*num_queues == 0) {
1935 dev_err(&info->xbdev->dev, "no queues\n");
1941 /* Common code used when first setting up, and when resuming. */
1942 static int talk_to_netback(struct xenbus_device *dev,
1943 struct netfront_info *info)
1945 const char *message;
1946 struct xenbus_transaction xbt;
1948 unsigned int feature_split_evtchn;
1950 unsigned int max_queues = 0;
1951 struct netfront_queue *queue = NULL;
1952 unsigned int num_queues = 1;
1954 info->netdev->irq = 0;
1956 /* Check if backend supports multiple queues */
1957 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1958 "multi-queue-max-queues", "%u", &max_queues);
1961 num_queues = min(max_queues, xennet_max_queues);
1963 /* Check feature-split-event-channels */
1964 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1965 "feature-split-event-channels", "%u",
1966 &feature_split_evtchn);
1968 feature_split_evtchn = 0;
1970 /* Read mac addr. */
1971 err = xen_net_read_mac(dev, info->netdev->dev_addr);
1973 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
1979 xennet_destroy_queues(info);
1981 /* For the case of a reconnect reset the "broken" indicator. */
1982 info->broken = false;
1984 err = xennet_create_queues(info, &num_queues);
1986 xenbus_dev_fatal(dev, err, "creating queues");
1987 kfree(info->queues);
1988 info->queues = NULL;
1993 /* Create shared ring, alloc event channel -- for each queue */
1994 for (i = 0; i < num_queues; ++i) {
1995 queue = &info->queues[i];
1996 err = setup_netfront(dev, queue, feature_split_evtchn);
2002 err = xenbus_transaction_start(&xbt);
2004 xenbus_dev_fatal(dev, err, "starting transaction");
2008 if (xenbus_exists(XBT_NIL,
2009 info->xbdev->otherend, "multi-queue-max-queues")) {
2010 /* Write the number of queues */
2011 err = xenbus_printf(xbt, dev->nodename,
2012 "multi-queue-num-queues", "%u", num_queues);
2014 message = "writing multi-queue-num-queues";
2015 goto abort_transaction_no_dev_fatal;
2019 if (num_queues == 1) {
2020 err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
2022 goto abort_transaction_no_dev_fatal;
2024 /* Write the keys for each queue */
2025 for (i = 0; i < num_queues; ++i) {
2026 queue = &info->queues[i];
2027 err = write_queue_xenstore_keys(queue, &xbt, 1); /* hierarchical */
2029 goto abort_transaction_no_dev_fatal;
2033 /* The remaining keys are not queue-specific */
2034 err = xenbus_printf(xbt, dev->nodename, "request-rx-copy", "%u",
2037 message = "writing request-rx-copy";
2038 goto abort_transaction;
2041 err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
2043 message = "writing feature-rx-notify";
2044 goto abort_transaction;
2047 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", 1);
2049 message = "writing feature-sg";
2050 goto abort_transaction;
2053 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4", "%d", 1);
2055 message = "writing feature-gso-tcpv4";
2056 goto abort_transaction;
2059 err = xenbus_write(xbt, dev->nodename, "feature-gso-tcpv6", "1");
2061 message = "writing feature-gso-tcpv6";
2062 goto abort_transaction;
2065 err = xenbus_write(xbt, dev->nodename, "feature-ipv6-csum-offload",
2068 message = "writing feature-ipv6-csum-offload";
2069 goto abort_transaction;
2072 err = xenbus_transaction_end(xbt, 0);
2076 xenbus_dev_fatal(dev, err, "completing transaction");
2083 xenbus_dev_fatal(dev, err, "%s", message);
2084 abort_transaction_no_dev_fatal:
2085 xenbus_transaction_end(xbt, 1);
2087 xennet_disconnect_backend(info);
2089 xennet_destroy_queues(info);
2093 device_unregister(&dev->dev);
2097 static int xennet_connect(struct net_device *dev)
2099 struct netfront_info *np = netdev_priv(dev);
2100 unsigned int num_queues = 0;
2102 unsigned int feature_rx_copy;
2104 struct netfront_queue *queue = NULL;
2106 err = xenbus_scanf(XBT_NIL, np->xbdev->otherend,
2107 "feature-rx-copy", "%u", &feature_rx_copy);
2109 feature_rx_copy = 0;
2111 if (!feature_rx_copy) {
2113 "backend does not support copying receive path\n");
2117 err = talk_to_netback(np->xbdev, np);
2121 /* talk_to_netback() sets the correct number of queues */
2122 num_queues = dev->real_num_tx_queues;
2124 if (dev->reg_state == NETREG_UNINITIALIZED) {
2125 err = register_netdev(dev);
2127 pr_warn("%s: register_netdev err=%d\n", __func__, err);
2128 device_unregister(&np->xbdev->dev);
2134 netdev_update_features(dev);
2138 * All public and private state should now be sane. Get
2139 * ready to start sending and receiving packets and give the driver
2140 * domain a kick because we've probably just requeued some
2143 netif_tx_lock_bh(np->netdev);
2144 netif_device_attach(np->netdev);
2145 netif_tx_unlock_bh(np->netdev);
2147 netif_carrier_on(np->netdev);
2148 for (j = 0; j < num_queues; ++j) {
2149 queue = &np->queues[j];
2151 notify_remote_via_irq(queue->tx_irq);
2152 if (queue->tx_irq != queue->rx_irq)
2153 notify_remote_via_irq(queue->rx_irq);
2155 spin_lock_irq(&queue->tx_lock);
2156 xennet_tx_buf_gc(queue);
2157 spin_unlock_irq(&queue->tx_lock);
2159 spin_lock_bh(&queue->rx_lock);
2160 xennet_alloc_rx_buffers(queue);
2161 spin_unlock_bh(&queue->rx_lock);
2168 * Callback received when the backend's state changes.
2170 static void netback_changed(struct xenbus_device *dev,
2171 enum xenbus_state backend_state)
2173 struct netfront_info *np = dev_get_drvdata(&dev->dev);
2174 struct net_device *netdev = np->netdev;
2176 dev_dbg(&dev->dev, "%s\n", xenbus_strstate(backend_state));
2178 wake_up_all(&module_wq);
2180 switch (backend_state) {
2181 case XenbusStateInitialising:
2182 case XenbusStateInitialised:
2183 case XenbusStateReconfiguring:
2184 case XenbusStateReconfigured:
2185 case XenbusStateUnknown:
2188 case XenbusStateInitWait:
2189 if (dev->state != XenbusStateInitialising)
2191 if (xennet_connect(netdev) != 0)
2193 xenbus_switch_state(dev, XenbusStateConnected);
2196 case XenbusStateConnected:
2197 netdev_notify_peers(netdev);
2200 case XenbusStateClosed:
2201 if (dev->state == XenbusStateClosed)
2203 /* Missed the backend's CLOSING state -- fallthrough */
2204 case XenbusStateClosing:
2205 xenbus_frontend_closed(dev);
2210 static const struct xennet_stat {
2211 char name[ETH_GSTRING_LEN];
2213 } xennet_stats[] = {
2215 "rx_gso_checksum_fixup",
2216 offsetof(struct netfront_info, rx_gso_checksum_fixup)
2220 static int xennet_get_sset_count(struct net_device *dev, int string_set)
2222 switch (string_set) {
2224 return ARRAY_SIZE(xennet_stats);
2230 static void xennet_get_ethtool_stats(struct net_device *dev,
2231 struct ethtool_stats *stats, u64 * data)
2233 void *np = netdev_priv(dev);
2236 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2237 data[i] = atomic_read((atomic_t *)(np + xennet_stats[i].offset));
2240 static void xennet_get_strings(struct net_device *dev, u32 stringset, u8 * data)
2244 switch (stringset) {
2246 for (i = 0; i < ARRAY_SIZE(xennet_stats); i++)
2247 memcpy(data + i * ETH_GSTRING_LEN,
2248 xennet_stats[i].name, ETH_GSTRING_LEN);
2253 static const struct ethtool_ops xennet_ethtool_ops =
2255 .get_link = ethtool_op_get_link,
2257 .get_sset_count = xennet_get_sset_count,
2258 .get_ethtool_stats = xennet_get_ethtool_stats,
2259 .get_strings = xennet_get_strings,
2263 static ssize_t show_rxbuf(struct device *dev,
2264 struct device_attribute *attr, char *buf)
2266 return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
2269 static ssize_t store_rxbuf(struct device *dev,
2270 struct device_attribute *attr,
2271 const char *buf, size_t len)
2274 unsigned long target;
2276 if (!capable(CAP_NET_ADMIN))
2279 target = simple_strtoul(buf, &endp, 0);
2283 /* rxbuf_min and rxbuf_max are no longer configurable. */
2288 static DEVICE_ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2289 static DEVICE_ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf);
2290 static DEVICE_ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL);
2292 static struct attribute *xennet_dev_attrs[] = {
2293 &dev_attr_rxbuf_min.attr,
2294 &dev_attr_rxbuf_max.attr,
2295 &dev_attr_rxbuf_cur.attr,
2299 static const struct attribute_group xennet_dev_group = {
2300 .attrs = xennet_dev_attrs
2302 #endif /* CONFIG_SYSFS */
2304 static void xennet_bus_close(struct xenbus_device *dev)
2308 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2311 xenbus_switch_state(dev, XenbusStateClosing);
2312 ret = wait_event_timeout(module_wq,
2313 xenbus_read_driver_state(dev->otherend) ==
2314 XenbusStateClosing ||
2315 xenbus_read_driver_state(dev->otherend) ==
2316 XenbusStateClosed ||
2317 xenbus_read_driver_state(dev->otherend) ==
2322 if (xenbus_read_driver_state(dev->otherend) == XenbusStateClosed)
2326 xenbus_switch_state(dev, XenbusStateClosed);
2327 ret = wait_event_timeout(module_wq,
2328 xenbus_read_driver_state(dev->otherend) ==
2329 XenbusStateClosed ||
2330 xenbus_read_driver_state(dev->otherend) ==
2336 static int xennet_remove(struct xenbus_device *dev)
2338 struct netfront_info *info = dev_get_drvdata(&dev->dev);
2340 xennet_bus_close(dev);
2341 xennet_disconnect_backend(info);
2343 if (info->netdev->reg_state == NETREG_REGISTERED)
2344 unregister_netdev(info->netdev);
2348 xennet_destroy_queues(info);
2351 xennet_free_netdev(info->netdev);
2356 static const struct xenbus_device_id netfront_ids[] = {
2361 static struct xenbus_driver netfront_driver = {
2362 .ids = netfront_ids,
2363 .probe = netfront_probe,
2364 .remove = xennet_remove,
2365 .resume = netfront_resume,
2366 .otherend_changed = netback_changed,
2369 static int __init netif_init(void)
2374 if (!xen_has_pv_nic_devices())
2377 pr_info("Initialising Xen virtual ethernet driver\n");
2379 /* Allow as many queues as there are CPUs if user has not
2380 * specified a value.
2382 if (xennet_max_queues == 0)
2383 xennet_max_queues = num_online_cpus();
2385 return xenbus_register_frontend(&netfront_driver);
2387 module_init(netif_init);
2390 static void __exit netif_exit(void)
2392 xenbus_unregister_driver(&netfront_driver);
2394 module_exit(netif_exit);
2396 MODULE_DESCRIPTION("Xen virtual network device frontend");
2397 MODULE_LICENSE("GPL");
2398 MODULE_ALIAS("xen:vif");
2399 MODULE_ALIAS("xennet");