2 * Back-end of the driver for virtual network devices. This portion of the
3 * driver exports a 'unified' network-device interface that can be accessed
4 * by any operating system that implements a compatible front end. A
5 * reference front-end implementation can be found in:
6 * drivers/net/xen-netfront.c
8 * Copyright (c) 2002-2005, K A Fraser
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License version 2
12 * as published by the Free Software Foundation; or, when distributed
13 * separately from the Linux kernel or incorporated into other
14 * software packages, subject to the following license:
16 * Permission is hereby granted, free of charge, to any person obtaining a copy
17 * of this source file (the "Software"), to deal in the Software without
18 * restriction, including without limitation the rights to use, copy, modify,
19 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
20 * and to permit persons to whom the Software is furnished to do so, subject to
21 * the following conditions:
23 * The above copyright notice and this permission notice shall be included in
24 * all copies or substantial portions of the Software.
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
29 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
30 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
31 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
37 #include <linux/kthread.h>
38 #include <linux/if_vlan.h>
39 #include <linux/udp.h>
40 #include <linux/highmem.h>
45 #include <xen/events.h>
46 #include <xen/interface/memory.h>
49 #include <asm/xen/hypercall.h>
51 /* Provide an option to disable split event channels at load time as
52 * event channels are limited resource. Split event channels are
55 bool separate_tx_rx_irq = true;
56 module_param(separate_tx_rx_irq, bool, 0644);
58 /* The time that packets can stay on the guest Rx internal queue
59 * before they are dropped.
61 unsigned int rx_drain_timeout_msecs = 10000;
62 module_param(rx_drain_timeout_msecs, uint, 0444);
64 /* The length of time before the frontend is considered unresponsive
65 * because it isn't providing Rx slots.
67 unsigned int rx_stall_timeout_msecs = 60000;
68 module_param(rx_stall_timeout_msecs, uint, 0444);
70 unsigned int xenvif_max_queues;
71 module_param_named(max_queues, xenvif_max_queues, uint, 0644);
72 MODULE_PARM_DESC(max_queues,
73 "Maximum number of queues per virtual interface");
76 * This is the maximum slots a skb can have. If a guest sends a skb
77 * which exceeds this limit it is considered malicious.
79 #define FATAL_SKB_SLOTS_DEFAULT 20
80 static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT;
81 module_param(fatal_skb_slots, uint, 0444);
83 /* The amount to copy out of the first guest Tx slot into the skb's
84 * linear area. If the first slot has more data, it will be mapped
85 * and put into the first frag.
87 * This is sized to avoid pulling headers from the frags for most
90 #define XEN_NETBACK_TX_COPY_LEN 128
92 /* This is the maximum number of flows in the hash cache. */
93 #define XENVIF_HASH_CACHE_SIZE_DEFAULT 64
94 unsigned int xenvif_hash_cache_size = XENVIF_HASH_CACHE_SIZE_DEFAULT;
95 module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, 0644);
96 MODULE_PARM_DESC(hash_cache_size, "Number of flows in the hash cache");
98 static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
101 static void make_tx_response(struct xenvif_queue *queue,
102 struct xen_netif_tx_request *txp,
103 unsigned int extra_count,
105 static void push_tx_responses(struct xenvif_queue *queue);
107 static inline int tx_work_todo(struct xenvif_queue *queue);
109 static inline unsigned long idx_to_pfn(struct xenvif_queue *queue,
112 return page_to_pfn(queue->mmap_pages[idx]);
115 static inline unsigned long idx_to_kaddr(struct xenvif_queue *queue,
118 return (unsigned long)pfn_to_kaddr(idx_to_pfn(queue, idx));
121 #define callback_param(vif, pending_idx) \
122 (vif->pending_tx_info[pending_idx].callback_struct)
124 /* Find the containing VIF's structure from a pointer in pending_tx_info array
126 static inline struct xenvif_queue *ubuf_to_queue(const struct ubuf_info *ubuf)
128 u16 pending_idx = ubuf->desc;
129 struct pending_tx_info *temp =
130 container_of(ubuf, struct pending_tx_info, callback_struct);
131 return container_of(temp - pending_idx,
136 static u16 frag_get_pending_idx(skb_frag_t *frag)
138 return (u16)frag->page_offset;
141 static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx)
143 frag->page_offset = pending_idx;
146 static inline pending_ring_idx_t pending_index(unsigned i)
148 return i & (MAX_PENDING_REQS-1);
151 void xenvif_kick_thread(struct xenvif_queue *queue)
156 void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue)
160 RING_FINAL_CHECK_FOR_REQUESTS(&queue->tx, more_to_do);
163 napi_schedule(&queue->napi);
166 static void tx_add_credit(struct xenvif_queue *queue)
168 unsigned long max_burst, max_credit;
171 * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
172 * Otherwise the interface can seize up due to insufficient credit.
174 max_burst = max(131072UL, queue->credit_bytes);
176 /* Take care that adding a new chunk of credit doesn't wrap to zero. */
177 max_credit = queue->remaining_credit + queue->credit_bytes;
178 if (max_credit < queue->remaining_credit)
179 max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
181 queue->remaining_credit = min(max_credit, max_burst);
184 void xenvif_tx_credit_callback(unsigned long data)
186 struct xenvif_queue *queue = (struct xenvif_queue *)data;
187 tx_add_credit(queue);
188 xenvif_napi_schedule_or_enable_events(queue);
191 static void xenvif_tx_err(struct xenvif_queue *queue,
192 struct xen_netif_tx_request *txp,
193 unsigned int extra_count, RING_IDX end)
195 RING_IDX cons = queue->tx.req_cons;
199 spin_lock_irqsave(&queue->response_lock, flags);
200 make_tx_response(queue, txp, extra_count, XEN_NETIF_RSP_ERROR);
201 push_tx_responses(queue);
202 spin_unlock_irqrestore(&queue->response_lock, flags);
205 RING_COPY_REQUEST(&queue->tx, cons++, txp);
206 extra_count = 0; /* only the first frag can have extras */
208 queue->tx.req_cons = cons;
211 static void xenvif_fatal_tx_err(struct xenvif *vif)
213 netdev_err(vif->dev, "fatal error; disabling device\n");
214 vif->disabled = true;
215 /* Disable the vif from queue 0's kthread */
217 xenvif_kick_thread(&vif->queues[0]);
220 static int xenvif_count_requests(struct xenvif_queue *queue,
221 struct xen_netif_tx_request *first,
222 unsigned int extra_count,
223 struct xen_netif_tx_request *txp,
226 RING_IDX cons = queue->tx.req_cons;
231 if (!(first->flags & XEN_NETTXF_more_data))
235 struct xen_netif_tx_request dropped_tx = { 0 };
237 if (slots >= work_to_do) {
238 netdev_err(queue->vif->dev,
239 "Asked for %d slots but exceeds this limit\n",
241 xenvif_fatal_tx_err(queue->vif);
245 /* This guest is really using too many slots and
246 * considered malicious.
248 if (unlikely(slots >= fatal_skb_slots)) {
249 netdev_err(queue->vif->dev,
250 "Malicious frontend using %d slots, threshold %u\n",
251 slots, fatal_skb_slots);
252 xenvif_fatal_tx_err(queue->vif);
256 /* Xen network protocol had implicit dependency on
257 * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to
258 * the historical MAX_SKB_FRAGS value 18 to honor the
259 * same behavior as before. Any packet using more than
260 * 18 slots but less than fatal_skb_slots slots is
263 if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) {
265 netdev_dbg(queue->vif->dev,
266 "Too many slots (%d) exceeding limit (%d), dropping packet\n",
267 slots, XEN_NETBK_LEGACY_SLOTS_MAX);
274 RING_COPY_REQUEST(&queue->tx, cons + slots, txp);
276 /* If the guest submitted a frame >= 64 KiB then
277 * first->size overflowed and following slots will
278 * appear to be larger than the frame.
280 * This cannot be fatal error as there are buggy
281 * frontends that do this.
283 * Consume all slots and drop the packet.
285 if (!drop_err && txp->size > first->size) {
287 netdev_dbg(queue->vif->dev,
288 "Invalid tx request, slot size %u > remaining size %u\n",
289 txp->size, first->size);
293 first->size -= txp->size;
296 if (unlikely((txp->offset + txp->size) > XEN_PAGE_SIZE)) {
297 netdev_err(queue->vif->dev, "Cross page boundary, txp->offset: %u, size: %u\n",
298 txp->offset, txp->size);
299 xenvif_fatal_tx_err(queue->vif);
303 more_data = txp->flags & XEN_NETTXF_more_data;
311 xenvif_tx_err(queue, first, extra_count, cons + slots);
319 struct xenvif_tx_cb {
323 #define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb)
325 static inline void xenvif_tx_create_map_op(struct xenvif_queue *queue,
327 struct xen_netif_tx_request *txp,
328 unsigned int extra_count,
329 struct gnttab_map_grant_ref *mop)
331 queue->pages_to_map[mop-queue->tx_map_ops] = queue->mmap_pages[pending_idx];
332 gnttab_set_map_op(mop, idx_to_kaddr(queue, pending_idx),
333 GNTMAP_host_map | GNTMAP_readonly,
334 txp->gref, queue->vif->domid);
336 memcpy(&queue->pending_tx_info[pending_idx].req, txp,
338 queue->pending_tx_info[pending_idx].extra_count = extra_count;
341 static inline struct sk_buff *xenvif_alloc_skb(unsigned int size)
343 struct sk_buff *skb =
344 alloc_skb(size + NET_SKB_PAD + NET_IP_ALIGN,
345 GFP_ATOMIC | __GFP_NOWARN);
346 if (unlikely(skb == NULL))
349 /* Packets passed to netif_rx() must have some headroom. */
350 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
352 /* Initialize it here to avoid later surprises */
353 skb_shinfo(skb)->destructor_arg = NULL;
358 static struct gnttab_map_grant_ref *xenvif_get_requests(struct xenvif_queue *queue,
360 struct xen_netif_tx_request *txp,
361 struct gnttab_map_grant_ref *gop,
362 unsigned int frag_overflow,
363 struct sk_buff *nskb)
365 struct skb_shared_info *shinfo = skb_shinfo(skb);
366 skb_frag_t *frags = shinfo->frags;
367 u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
369 pending_ring_idx_t index;
370 unsigned int nr_slots;
372 nr_slots = shinfo->nr_frags;
374 /* Skip first skb fragment if it is on same page as header fragment. */
375 start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
377 for (shinfo->nr_frags = start; shinfo->nr_frags < nr_slots;
378 shinfo->nr_frags++, txp++, gop++) {
379 index = pending_index(queue->pending_cons++);
380 pending_idx = queue->pending_ring[index];
381 xenvif_tx_create_map_op(queue, pending_idx, txp, 0, gop);
382 frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx);
387 shinfo = skb_shinfo(nskb);
388 frags = shinfo->frags;
390 for (shinfo->nr_frags = 0; shinfo->nr_frags < frag_overflow;
391 shinfo->nr_frags++, txp++, gop++) {
392 index = pending_index(queue->pending_cons++);
393 pending_idx = queue->pending_ring[index];
394 xenvif_tx_create_map_op(queue, pending_idx, txp, 0,
396 frag_set_pending_idx(&frags[shinfo->nr_frags],
400 skb_shinfo(skb)->frag_list = nskb;
406 static inline void xenvif_grant_handle_set(struct xenvif_queue *queue,
408 grant_handle_t handle)
410 if (unlikely(queue->grant_tx_handle[pending_idx] !=
411 NETBACK_INVALID_HANDLE)) {
412 netdev_err(queue->vif->dev,
413 "Trying to overwrite active handle! pending_idx: 0x%x\n",
417 queue->grant_tx_handle[pending_idx] = handle;
420 static inline void xenvif_grant_handle_reset(struct xenvif_queue *queue,
423 if (unlikely(queue->grant_tx_handle[pending_idx] ==
424 NETBACK_INVALID_HANDLE)) {
425 netdev_err(queue->vif->dev,
426 "Trying to unmap invalid handle! pending_idx: 0x%x\n",
430 queue->grant_tx_handle[pending_idx] = NETBACK_INVALID_HANDLE;
433 static int xenvif_tx_check_gop(struct xenvif_queue *queue,
435 struct gnttab_map_grant_ref **gopp_map,
436 struct gnttab_copy **gopp_copy)
438 struct gnttab_map_grant_ref *gop_map = *gopp_map;
439 u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
440 /* This always points to the shinfo of the skb being checked, which
441 * could be either the first or the one on the frag_list
443 struct skb_shared_info *shinfo = skb_shinfo(skb);
444 /* If this is non-NULL, we are currently checking the frag_list skb, and
445 * this points to the shinfo of the first one
447 struct skb_shared_info *first_shinfo = NULL;
448 int nr_frags = shinfo->nr_frags;
449 const bool sharedslot = nr_frags &&
450 frag_get_pending_idx(&shinfo->frags[0]) == pending_idx;
453 /* Check status of header. */
454 err = (*gopp_copy)->status;
457 netdev_dbg(queue->vif->dev,
458 "Grant copy of header failed! status: %d pending_idx: %u ref: %u\n",
459 (*gopp_copy)->status,
461 (*gopp_copy)->source.u.ref);
462 /* The first frag might still have this slot mapped */
464 xenvif_idx_release(queue, pending_idx,
465 XEN_NETIF_RSP_ERROR);
470 for (i = 0; i < nr_frags; i++, gop_map++) {
473 pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
475 /* Check error status: if okay then remember grant handle. */
476 newerr = gop_map->status;
478 if (likely(!newerr)) {
479 xenvif_grant_handle_set(queue,
482 /* Had a previous error? Invalidate this fragment. */
484 xenvif_idx_unmap(queue, pending_idx);
485 /* If the mapping of the first frag was OK, but
486 * the header's copy failed, and they are
487 * sharing a slot, send an error
489 if (i == 0 && sharedslot)
490 xenvif_idx_release(queue, pending_idx,
491 XEN_NETIF_RSP_ERROR);
493 xenvif_idx_release(queue, pending_idx,
499 /* Error on this fragment: respond to client with an error. */
501 netdev_dbg(queue->vif->dev,
502 "Grant map of %d. frag failed! status: %d pending_idx: %u ref: %u\n",
508 xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_ERROR);
510 /* Not the first error? Preceding frags already invalidated. */
514 /* First error: if the header haven't shared a slot with the
515 * first frag, release it as well.
518 xenvif_idx_release(queue,
519 XENVIF_TX_CB(skb)->pending_idx,
522 /* Invalidate preceding fragments of this skb. */
523 for (j = 0; j < i; j++) {
524 pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
525 xenvif_idx_unmap(queue, pending_idx);
526 xenvif_idx_release(queue, pending_idx,
530 /* And if we found the error while checking the frag_list, unmap
531 * the first skb's frags
534 for (j = 0; j < first_shinfo->nr_frags; j++) {
535 pending_idx = frag_get_pending_idx(&first_shinfo->frags[j]);
536 xenvif_idx_unmap(queue, pending_idx);
537 xenvif_idx_release(queue, pending_idx,
542 /* Remember the error: invalidate all subsequent fragments. */
546 if (skb_has_frag_list(skb) && !first_shinfo) {
547 first_shinfo = skb_shinfo(skb);
548 shinfo = skb_shinfo(skb_shinfo(skb)->frag_list);
549 nr_frags = shinfo->nr_frags;
558 static void xenvif_fill_frags(struct xenvif_queue *queue, struct sk_buff *skb)
560 struct skb_shared_info *shinfo = skb_shinfo(skb);
561 int nr_frags = shinfo->nr_frags;
563 u16 prev_pending_idx = INVALID_PENDING_IDX;
565 for (i = 0; i < nr_frags; i++) {
566 skb_frag_t *frag = shinfo->frags + i;
567 struct xen_netif_tx_request *txp;
571 pending_idx = frag_get_pending_idx(frag);
573 /* If this is not the first frag, chain it to the previous*/
574 if (prev_pending_idx == INVALID_PENDING_IDX)
575 skb_shinfo(skb)->destructor_arg =
576 &callback_param(queue, pending_idx);
578 callback_param(queue, prev_pending_idx).ctx =
579 &callback_param(queue, pending_idx);
581 callback_param(queue, pending_idx).ctx = NULL;
582 prev_pending_idx = pending_idx;
584 txp = &queue->pending_tx_info[pending_idx].req;
585 page = virt_to_page(idx_to_kaddr(queue, pending_idx));
586 __skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
587 skb->len += txp->size;
588 skb->data_len += txp->size;
589 skb->truesize += txp->size;
591 /* Take an extra reference to offset network stack's put_page */
592 get_page(queue->mmap_pages[pending_idx]);
596 static int xenvif_get_extras(struct xenvif_queue *queue,
597 struct xen_netif_extra_info *extras,
598 unsigned int *extra_count,
601 struct xen_netif_extra_info extra;
602 RING_IDX cons = queue->tx.req_cons;
605 if (unlikely(work_to_do-- <= 0)) {
606 netdev_err(queue->vif->dev, "Missing extra info\n");
607 xenvif_fatal_tx_err(queue->vif);
611 RING_COPY_REQUEST(&queue->tx, cons, &extra);
613 queue->tx.req_cons = ++cons;
616 if (unlikely(!extra.type ||
617 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
618 netdev_err(queue->vif->dev,
619 "Invalid extra type: %d\n", extra.type);
620 xenvif_fatal_tx_err(queue->vif);
624 memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
625 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
630 static int xenvif_set_skb_gso(struct xenvif *vif,
632 struct xen_netif_extra_info *gso)
634 if (!gso->u.gso.size) {
635 netdev_err(vif->dev, "GSO size must not be zero.\n");
636 xenvif_fatal_tx_err(vif);
640 switch (gso->u.gso.type) {
641 case XEN_NETIF_GSO_TYPE_TCPV4:
642 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
644 case XEN_NETIF_GSO_TYPE_TCPV6:
645 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
648 netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
649 xenvif_fatal_tx_err(vif);
653 skb_shinfo(skb)->gso_size = gso->u.gso.size;
654 /* gso_segs will be calculated later */
659 static int checksum_setup(struct xenvif_queue *queue, struct sk_buff *skb)
661 bool recalculate_partial_csum = false;
663 /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
664 * peers can fail to set NETRXF_csum_blank when sending a GSO
665 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
666 * recalculate the partial checksum.
668 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
669 queue->stats.rx_gso_checksum_fixup++;
670 skb->ip_summed = CHECKSUM_PARTIAL;
671 recalculate_partial_csum = true;
674 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
675 if (skb->ip_summed != CHECKSUM_PARTIAL)
678 return skb_checksum_setup(skb, recalculate_partial_csum);
681 static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size)
683 u64 now = get_jiffies_64();
684 u64 next_credit = queue->credit_window_start +
685 msecs_to_jiffies(queue->credit_usec / 1000);
687 /* Timer could already be pending in rare cases. */
688 if (timer_pending(&queue->credit_timeout))
691 /* Passed the point where we can replenish credit? */
692 if (time_after_eq64(now, next_credit)) {
693 queue->credit_window_start = now;
694 tx_add_credit(queue);
697 /* Still too big to send right now? Set a callback. */
698 if (size > queue->remaining_credit) {
699 queue->credit_timeout.data =
700 (unsigned long)queue;
701 mod_timer(&queue->credit_timeout,
703 queue->credit_window_start = next_credit;
711 /* No locking is required in xenvif_mcast_add/del() as they are
712 * only ever invoked from NAPI poll. An RCU list is used because
713 * xenvif_mcast_match() is called asynchronously, during start_xmit.
716 static int xenvif_mcast_add(struct xenvif *vif, const u8 *addr)
718 struct xenvif_mcast_addr *mcast;
720 if (vif->fe_mcast_count == XEN_NETBK_MCAST_MAX) {
723 "Too many multicast addresses\n");
727 mcast = kzalloc(sizeof(*mcast), GFP_ATOMIC);
731 ether_addr_copy(mcast->addr, addr);
732 list_add_tail_rcu(&mcast->entry, &vif->fe_mcast_addr);
733 vif->fe_mcast_count++;
738 static void xenvif_mcast_del(struct xenvif *vif, const u8 *addr)
740 struct xenvif_mcast_addr *mcast;
742 list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
743 if (ether_addr_equal(addr, mcast->addr)) {
744 --vif->fe_mcast_count;
745 list_del_rcu(&mcast->entry);
746 kfree_rcu(mcast, rcu);
752 bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr)
754 struct xenvif_mcast_addr *mcast;
757 list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
758 if (ether_addr_equal(addr, mcast->addr)) {
768 void xenvif_mcast_addr_list_free(struct xenvif *vif)
770 /* No need for locking or RCU here. NAPI poll and TX queue
773 while (!list_empty(&vif->fe_mcast_addr)) {
774 struct xenvif_mcast_addr *mcast;
776 mcast = list_first_entry(&vif->fe_mcast_addr,
777 struct xenvif_mcast_addr,
779 --vif->fe_mcast_count;
780 list_del(&mcast->entry);
785 static void xenvif_tx_build_gops(struct xenvif_queue *queue,
790 struct gnttab_map_grant_ref *gop = queue->tx_map_ops;
791 struct sk_buff *skb, *nskb;
793 unsigned int frag_overflow;
795 while (skb_queue_len(&queue->tx_queue) < budget) {
796 struct xen_netif_tx_request txreq;
797 struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
798 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
799 unsigned int extra_count;
803 unsigned int data_len;
804 pending_ring_idx_t index;
806 if (queue->tx.sring->req_prod - queue->tx.req_cons >
807 XEN_NETIF_TX_RING_SIZE) {
808 netdev_err(queue->vif->dev,
809 "Impossible number of requests. "
810 "req_prod %d, req_cons %d, size %ld\n",
811 queue->tx.sring->req_prod, queue->tx.req_cons,
812 XEN_NETIF_TX_RING_SIZE);
813 xenvif_fatal_tx_err(queue->vif);
817 work_to_do = RING_HAS_UNCONSUMED_REQUESTS(&queue->tx);
821 idx = queue->tx.req_cons;
822 rmb(); /* Ensure that we see the request before we copy it. */
823 RING_COPY_REQUEST(&queue->tx, idx, &txreq);
825 /* Credit-based scheduling. */
826 if (txreq.size > queue->remaining_credit &&
827 tx_credit_exceeded(queue, txreq.size))
830 queue->remaining_credit -= txreq.size;
833 queue->tx.req_cons = ++idx;
835 memset(extras, 0, sizeof(extras));
837 if (txreq.flags & XEN_NETTXF_extra_info) {
838 work_to_do = xenvif_get_extras(queue, extras,
841 idx = queue->tx.req_cons;
842 if (unlikely(work_to_do < 0))
846 if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1].type) {
847 struct xen_netif_extra_info *extra;
849 extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1];
850 ret = xenvif_mcast_add(queue->vif, extra->u.mcast.addr);
852 make_tx_response(queue, &txreq, extra_count,
855 XEN_NETIF_RSP_ERROR);
856 push_tx_responses(queue);
860 if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1].type) {
861 struct xen_netif_extra_info *extra;
863 extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1];
864 xenvif_mcast_del(queue->vif, extra->u.mcast.addr);
866 make_tx_response(queue, &txreq, extra_count,
868 push_tx_responses(queue);
872 ret = xenvif_count_requests(queue, &txreq, extra_count,
873 txfrags, work_to_do);
874 if (unlikely(ret < 0))
879 if (unlikely(txreq.size < ETH_HLEN)) {
880 netdev_dbg(queue->vif->dev,
881 "Bad packet size: %d\n", txreq.size);
882 xenvif_tx_err(queue, &txreq, extra_count, idx);
886 /* No crossing a page as the payload mustn't fragment. */
887 if (unlikely((txreq.offset + txreq.size) > XEN_PAGE_SIZE)) {
888 netdev_err(queue->vif->dev,
889 "txreq.offset: %u, size: %u, end: %lu\n",
890 txreq.offset, txreq.size,
891 (unsigned long)(txreq.offset&~XEN_PAGE_MASK) + txreq.size);
892 xenvif_fatal_tx_err(queue->vif);
896 index = pending_index(queue->pending_cons);
897 pending_idx = queue->pending_ring[index];
899 data_len = (txreq.size > XEN_NETBACK_TX_COPY_LEN &&
900 ret < XEN_NETBK_LEGACY_SLOTS_MAX) ?
901 XEN_NETBACK_TX_COPY_LEN : txreq.size;
903 skb = xenvif_alloc_skb(data_len);
904 if (unlikely(skb == NULL)) {
905 netdev_dbg(queue->vif->dev,
906 "Can't allocate a skb in start_xmit.\n");
907 xenvif_tx_err(queue, &txreq, extra_count, idx);
911 skb_shinfo(skb)->nr_frags = ret;
912 if (data_len < txreq.size)
913 skb_shinfo(skb)->nr_frags++;
914 /* At this point shinfo->nr_frags is in fact the number of
915 * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
919 if (skb_shinfo(skb)->nr_frags > MAX_SKB_FRAGS) {
920 frag_overflow = skb_shinfo(skb)->nr_frags - MAX_SKB_FRAGS;
921 BUG_ON(frag_overflow > MAX_SKB_FRAGS);
922 skb_shinfo(skb)->nr_frags = MAX_SKB_FRAGS;
923 nskb = xenvif_alloc_skb(0);
924 if (unlikely(nskb == NULL)) {
926 xenvif_tx_err(queue, &txreq, extra_count, idx);
928 netdev_err(queue->vif->dev,
929 "Can't allocate the frag_list skb.\n");
934 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
935 struct xen_netif_extra_info *gso;
936 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
938 if (xenvif_set_skb_gso(queue->vif, skb, gso)) {
939 /* Failure in xenvif_set_skb_gso is fatal. */
946 if (extras[XEN_NETIF_EXTRA_TYPE_HASH - 1].type) {
947 struct xen_netif_extra_info *extra;
948 enum pkt_hash_types type = PKT_HASH_TYPE_NONE;
950 extra = &extras[XEN_NETIF_EXTRA_TYPE_HASH - 1];
952 switch (extra->u.hash.type) {
953 case _XEN_NETIF_CTRL_HASH_TYPE_IPV4:
954 case _XEN_NETIF_CTRL_HASH_TYPE_IPV6:
955 type = PKT_HASH_TYPE_L3;
958 case _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP:
959 case _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP:
960 type = PKT_HASH_TYPE_L4;
967 if (type != PKT_HASH_TYPE_NONE)
969 *(u32 *)extra->u.hash.value,
973 XENVIF_TX_CB(skb)->pending_idx = pending_idx;
975 __skb_put(skb, data_len);
976 queue->tx_copy_ops[*copy_ops].source.u.ref = txreq.gref;
977 queue->tx_copy_ops[*copy_ops].source.domid = queue->vif->domid;
978 queue->tx_copy_ops[*copy_ops].source.offset = txreq.offset;
980 queue->tx_copy_ops[*copy_ops].dest.u.gmfn =
981 virt_to_gfn(skb->data);
982 queue->tx_copy_ops[*copy_ops].dest.domid = DOMID_SELF;
983 queue->tx_copy_ops[*copy_ops].dest.offset =
984 offset_in_page(skb->data) & ~XEN_PAGE_MASK;
986 queue->tx_copy_ops[*copy_ops].len = data_len;
987 queue->tx_copy_ops[*copy_ops].flags = GNTCOPY_source_gref;
991 if (data_len < txreq.size) {
992 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
994 xenvif_tx_create_map_op(queue, pending_idx, &txreq,
998 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
999 INVALID_PENDING_IDX);
1000 memcpy(&queue->pending_tx_info[pending_idx].req,
1001 &txreq, sizeof(txreq));
1002 queue->pending_tx_info[pending_idx].extra_count =
1006 queue->pending_cons++;
1008 gop = xenvif_get_requests(queue, skb, txfrags, gop,
1009 frag_overflow, nskb);
1011 __skb_queue_tail(&queue->tx_queue, skb);
1013 queue->tx.req_cons = idx;
1015 if (((gop-queue->tx_map_ops) >= ARRAY_SIZE(queue->tx_map_ops)) ||
1016 (*copy_ops >= ARRAY_SIZE(queue->tx_copy_ops)))
1020 (*map_ops) = gop - queue->tx_map_ops;
1024 /* Consolidate skb with a frag_list into a brand new one with local pages on
1025 * frags. Returns 0 or -ENOMEM if can't allocate new pages.
1027 static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *skb)
1029 unsigned int offset = skb_headlen(skb);
1030 skb_frag_t frags[MAX_SKB_FRAGS];
1032 struct ubuf_info *uarg;
1033 struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
1035 queue->stats.tx_zerocopy_sent += 2;
1036 queue->stats.tx_frag_overflow++;
1038 xenvif_fill_frags(queue, nskb);
1039 /* Subtract frags size, we will correct it later */
1040 skb->truesize -= skb->data_len;
1041 skb->len += nskb->len;
1042 skb->data_len += nskb->len;
1044 /* create a brand new frags array and coalesce there */
1045 for (i = 0; offset < skb->len; i++) {
1049 BUG_ON(i >= MAX_SKB_FRAGS);
1050 page = alloc_page(GFP_ATOMIC);
1053 skb->truesize += skb->data_len;
1054 for (j = 0; j < i; j++)
1055 put_page(frags[j].page.p);
1059 if (offset + PAGE_SIZE < skb->len)
1062 len = skb->len - offset;
1063 if (skb_copy_bits(skb, offset, page_address(page), len))
1067 frags[i].page.p = page;
1068 frags[i].page_offset = 0;
1069 skb_frag_size_set(&frags[i], len);
1072 /* Copied all the bits from the frag list -- free it. */
1073 skb_frag_list_init(skb);
1074 xenvif_skb_zerocopy_prepare(queue, nskb);
1077 /* Release all the original (foreign) frags. */
1078 for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
1079 skb_frag_unref(skb, f);
1080 uarg = skb_shinfo(skb)->destructor_arg;
1081 /* increase inflight counter to offset decrement in callback */
1082 atomic_inc(&queue->inflight_packets);
1083 uarg->callback(uarg, true);
1084 skb_shinfo(skb)->destructor_arg = NULL;
1086 /* Fill the skb with the new (local) frags. */
1087 memcpy(skb_shinfo(skb)->frags, frags, i * sizeof(skb_frag_t));
1088 skb_shinfo(skb)->nr_frags = i;
1089 skb->truesize += i * PAGE_SIZE;
1094 static int xenvif_tx_submit(struct xenvif_queue *queue)
1096 struct gnttab_map_grant_ref *gop_map = queue->tx_map_ops;
1097 struct gnttab_copy *gop_copy = queue->tx_copy_ops;
1098 struct sk_buff *skb;
1101 while ((skb = __skb_dequeue(&queue->tx_queue)) != NULL) {
1102 struct xen_netif_tx_request *txp;
1106 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
1107 txp = &queue->pending_tx_info[pending_idx].req;
1109 /* Check the remap error code. */
1110 if (unlikely(xenvif_tx_check_gop(queue, skb, &gop_map, &gop_copy))) {
1111 /* If there was an error, xenvif_tx_check_gop is
1112 * expected to release all the frags which were mapped,
1113 * so kfree_skb shouldn't do it again
1115 skb_shinfo(skb)->nr_frags = 0;
1116 if (skb_has_frag_list(skb)) {
1117 struct sk_buff *nskb =
1118 skb_shinfo(skb)->frag_list;
1119 skb_shinfo(nskb)->nr_frags = 0;
1125 data_len = skb->len;
1126 callback_param(queue, pending_idx).ctx = NULL;
1127 if (data_len < txp->size) {
1128 /* Append the packet payload as a fragment. */
1129 txp->offset += data_len;
1130 txp->size -= data_len;
1132 /* Schedule a response immediately. */
1133 xenvif_idx_release(queue, pending_idx,
1134 XEN_NETIF_RSP_OKAY);
1137 if (txp->flags & XEN_NETTXF_csum_blank)
1138 skb->ip_summed = CHECKSUM_PARTIAL;
1139 else if (txp->flags & XEN_NETTXF_data_validated)
1140 skb->ip_summed = CHECKSUM_UNNECESSARY;
1142 xenvif_fill_frags(queue, skb);
1144 if (unlikely(skb_has_frag_list(skb))) {
1145 if (xenvif_handle_frag_list(queue, skb)) {
1146 if (net_ratelimit())
1147 netdev_err(queue->vif->dev,
1148 "Not enough memory to consolidate frag_list!\n");
1149 xenvif_skb_zerocopy_prepare(queue, skb);
1155 skb->dev = queue->vif->dev;
1156 skb->protocol = eth_type_trans(skb, skb->dev);
1157 skb_reset_network_header(skb);
1159 if (checksum_setup(queue, skb)) {
1160 netdev_dbg(queue->vif->dev,
1161 "Can't setup checksum in net_tx_action\n");
1162 /* We have to set this flag to trigger the callback */
1163 if (skb_shinfo(skb)->destructor_arg)
1164 xenvif_skb_zerocopy_prepare(queue, skb);
1169 skb_probe_transport_header(skb, 0);
1171 /* If the packet is GSO then we will have just set up the
1172 * transport header offset in checksum_setup so it's now
1173 * straightforward to calculate gso_segs.
1175 if (skb_is_gso(skb)) {
1176 int mss = skb_shinfo(skb)->gso_size;
1177 int hdrlen = skb_transport_header(skb) -
1178 skb_mac_header(skb) +
1181 skb_shinfo(skb)->gso_segs =
1182 DIV_ROUND_UP(skb->len - hdrlen, mss);
1185 queue->stats.rx_bytes += skb->len;
1186 queue->stats.rx_packets++;
1190 /* Set this flag right before netif_receive_skb, otherwise
1191 * someone might think this packet already left netback, and
1192 * do a skb_copy_ubufs while we are still in control of the
1193 * skb. E.g. the __pskb_pull_tail earlier can do such thing.
1195 if (skb_shinfo(skb)->destructor_arg) {
1196 xenvif_skb_zerocopy_prepare(queue, skb);
1197 queue->stats.tx_zerocopy_sent++;
1200 netif_receive_skb(skb);
1206 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success)
1208 unsigned long flags;
1209 pending_ring_idx_t index;
1210 struct xenvif_queue *queue = ubuf_to_queue(ubuf);
1212 /* This is the only place where we grab this lock, to protect callbacks
1215 spin_lock_irqsave(&queue->callback_lock, flags);
1217 u16 pending_idx = ubuf->desc;
1218 ubuf = (struct ubuf_info *) ubuf->ctx;
1219 BUG_ON(queue->dealloc_prod - queue->dealloc_cons >=
1221 index = pending_index(queue->dealloc_prod);
1222 queue->dealloc_ring[index] = pending_idx;
1223 /* Sync with xenvif_tx_dealloc_action:
1224 * insert idx then incr producer.
1227 queue->dealloc_prod++;
1229 spin_unlock_irqrestore(&queue->callback_lock, flags);
1231 if (likely(zerocopy_success))
1232 queue->stats.tx_zerocopy_success++;
1234 queue->stats.tx_zerocopy_fail++;
1235 xenvif_skb_zerocopy_complete(queue);
1238 static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue)
1240 struct gnttab_unmap_grant_ref *gop;
1241 pending_ring_idx_t dc, dp;
1242 u16 pending_idx, pending_idx_release[MAX_PENDING_REQS];
1245 dc = queue->dealloc_cons;
1246 gop = queue->tx_unmap_ops;
1248 /* Free up any grants we have finished using */
1250 dp = queue->dealloc_prod;
1252 /* Ensure we see all indices enqueued by all
1253 * xenvif_zerocopy_callback().
1258 BUG_ON(gop - queue->tx_unmap_ops >= MAX_PENDING_REQS);
1260 queue->dealloc_ring[pending_index(dc++)];
1262 pending_idx_release[gop - queue->tx_unmap_ops] =
1264 queue->pages_to_unmap[gop - queue->tx_unmap_ops] =
1265 queue->mmap_pages[pending_idx];
1266 gnttab_set_unmap_op(gop,
1267 idx_to_kaddr(queue, pending_idx),
1269 queue->grant_tx_handle[pending_idx]);
1270 xenvif_grant_handle_reset(queue, pending_idx);
1274 } while (dp != queue->dealloc_prod);
1276 queue->dealloc_cons = dc;
1278 if (gop - queue->tx_unmap_ops > 0) {
1280 ret = gnttab_unmap_refs(queue->tx_unmap_ops,
1282 queue->pages_to_unmap,
1283 gop - queue->tx_unmap_ops);
1285 netdev_err(queue->vif->dev, "Unmap fail: nr_ops %tu ret %d\n",
1286 gop - queue->tx_unmap_ops, ret);
1287 for (i = 0; i < gop - queue->tx_unmap_ops; ++i) {
1288 if (gop[i].status != GNTST_okay)
1289 netdev_err(queue->vif->dev,
1290 " host_addr: 0x%llx handle: 0x%x status: %d\n",
1299 for (i = 0; i < gop - queue->tx_unmap_ops; ++i)
1300 xenvif_idx_release(queue, pending_idx_release[i],
1301 XEN_NETIF_RSP_OKAY);
1305 /* Called after netfront has transmitted */
1306 int xenvif_tx_action(struct xenvif_queue *queue, int budget)
1308 unsigned nr_mops, nr_cops = 0;
1311 if (unlikely(!tx_work_todo(queue)))
1314 xenvif_tx_build_gops(queue, budget, &nr_cops, &nr_mops);
1319 gnttab_batch_copy(queue->tx_copy_ops, nr_cops);
1321 ret = gnttab_map_refs(queue->tx_map_ops,
1323 queue->pages_to_map,
1328 work_done = xenvif_tx_submit(queue);
1333 static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
1336 struct pending_tx_info *pending_tx_info;
1337 pending_ring_idx_t index;
1338 unsigned long flags;
1340 pending_tx_info = &queue->pending_tx_info[pending_idx];
1342 spin_lock_irqsave(&queue->response_lock, flags);
1344 make_tx_response(queue, &pending_tx_info->req,
1345 pending_tx_info->extra_count, status);
1347 /* Release the pending index before pusing the Tx response so
1348 * its available before a new Tx request is pushed by the
1351 index = pending_index(queue->pending_prod++);
1352 queue->pending_ring[index] = pending_idx;
1354 push_tx_responses(queue);
1356 spin_unlock_irqrestore(&queue->response_lock, flags);
1360 static void make_tx_response(struct xenvif_queue *queue,
1361 struct xen_netif_tx_request *txp,
1362 unsigned int extra_count,
1365 RING_IDX i = queue->tx.rsp_prod_pvt;
1366 struct xen_netif_tx_response *resp;
1368 resp = RING_GET_RESPONSE(&queue->tx, i);
1372 while (extra_count-- != 0)
1373 RING_GET_RESPONSE(&queue->tx, ++i)->status = XEN_NETIF_RSP_NULL;
1375 queue->tx.rsp_prod_pvt = ++i;
1378 static void push_tx_responses(struct xenvif_queue *queue)
1382 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->tx, notify);
1384 notify_remote_via_irq(queue->tx_irq);
1387 void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx)
1390 struct gnttab_unmap_grant_ref tx_unmap_op;
1392 gnttab_set_unmap_op(&tx_unmap_op,
1393 idx_to_kaddr(queue, pending_idx),
1395 queue->grant_tx_handle[pending_idx]);
1396 xenvif_grant_handle_reset(queue, pending_idx);
1398 ret = gnttab_unmap_refs(&tx_unmap_op, NULL,
1399 &queue->mmap_pages[pending_idx], 1);
1401 netdev_err(queue->vif->dev,
1402 "Unmap fail: ret: %d pending_idx: %d host_addr: %llx handle: 0x%x status: %d\n",
1405 tx_unmap_op.host_addr,
1407 tx_unmap_op.status);
1412 static inline int tx_work_todo(struct xenvif_queue *queue)
1414 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&queue->tx)))
1420 static inline bool tx_dealloc_work_todo(struct xenvif_queue *queue)
1422 return queue->dealloc_cons != queue->dealloc_prod;
1425 void xenvif_unmap_frontend_data_rings(struct xenvif_queue *queue)
1427 if (queue->tx.sring)
1428 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
1430 if (queue->rx.sring)
1431 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
1435 int xenvif_map_frontend_data_rings(struct xenvif_queue *queue,
1436 grant_ref_t tx_ring_ref,
1437 grant_ref_t rx_ring_ref)
1440 struct xen_netif_tx_sring *txs;
1441 struct xen_netif_rx_sring *rxs;
1445 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
1446 &tx_ring_ref, 1, &addr);
1450 txs = (struct xen_netif_tx_sring *)addr;
1451 BACK_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
1453 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
1454 &rx_ring_ref, 1, &addr);
1458 rxs = (struct xen_netif_rx_sring *)addr;
1459 BACK_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
1464 xenvif_unmap_frontend_data_rings(queue);
1468 static bool xenvif_dealloc_kthread_should_stop(struct xenvif_queue *queue)
1470 /* Dealloc thread must remain running until all inflight
1473 return kthread_should_stop() &&
1474 !atomic_read(&queue->inflight_packets);
1477 int xenvif_dealloc_kthread(void *data)
1479 struct xenvif_queue *queue = data;
1482 wait_event_interruptible(queue->dealloc_wq,
1483 tx_dealloc_work_todo(queue) ||
1484 xenvif_dealloc_kthread_should_stop(queue));
1485 if (xenvif_dealloc_kthread_should_stop(queue))
1488 xenvif_tx_dealloc_action(queue);
1492 /* Unmap anything remaining*/
1493 if (tx_dealloc_work_todo(queue))
1494 xenvif_tx_dealloc_action(queue);
1499 static void make_ctrl_response(struct xenvif *vif,
1500 const struct xen_netif_ctrl_request *req,
1501 u32 status, u32 data)
1503 RING_IDX idx = vif->ctrl.rsp_prod_pvt;
1504 struct xen_netif_ctrl_response rsp = {
1511 *RING_GET_RESPONSE(&vif->ctrl, idx) = rsp;
1512 vif->ctrl.rsp_prod_pvt = ++idx;
1515 static void push_ctrl_response(struct xenvif *vif)
1519 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->ctrl, notify);
1521 notify_remote_via_irq(vif->ctrl_irq);
1524 static void process_ctrl_request(struct xenvif *vif,
1525 const struct xen_netif_ctrl_request *req)
1527 u32 status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED;
1530 switch (req->type) {
1531 case XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM:
1532 status = xenvif_set_hash_alg(vif, req->data[0]);
1535 case XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS:
1536 status = xenvif_get_hash_flags(vif, &data);
1539 case XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS:
1540 status = xenvif_set_hash_flags(vif, req->data[0]);
1543 case XEN_NETIF_CTRL_TYPE_SET_HASH_KEY:
1544 status = xenvif_set_hash_key(vif, req->data[0],
1548 case XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE:
1549 status = XEN_NETIF_CTRL_STATUS_SUCCESS;
1550 data = XEN_NETBK_MAX_HASH_MAPPING_SIZE;
1553 case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE:
1554 status = xenvif_set_hash_mapping_size(vif,
1558 case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING:
1559 status = xenvif_set_hash_mapping(vif, req->data[0],
1568 make_ctrl_response(vif, req, status, data);
1569 push_ctrl_response(vif);
1572 static void xenvif_ctrl_action(struct xenvif *vif)
1575 RING_IDX req_prod, req_cons;
1577 req_prod = vif->ctrl.sring->req_prod;
1578 req_cons = vif->ctrl.req_cons;
1580 /* Make sure we can see requests before we process them. */
1583 if (req_cons == req_prod)
1586 while (req_cons != req_prod) {
1587 struct xen_netif_ctrl_request req;
1589 RING_COPY_REQUEST(&vif->ctrl, req_cons, &req);
1592 process_ctrl_request(vif, &req);
1595 vif->ctrl.req_cons = req_cons;
1596 vif->ctrl.sring->req_event = req_cons + 1;
1600 static bool xenvif_ctrl_work_todo(struct xenvif *vif)
1602 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->ctrl)))
1608 irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data)
1610 struct xenvif *vif = data;
1612 while (xenvif_ctrl_work_todo(vif))
1613 xenvif_ctrl_action(vif);
1618 static int __init netback_init(void)
1625 /* Allow as many queues as there are CPUs if user has not
1626 * specified a value.
1628 if (xenvif_max_queues == 0)
1629 xenvif_max_queues = num_online_cpus();
1631 if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
1632 pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
1633 fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX);
1634 fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX;
1637 rc = xenvif_xenbus_init();
1641 #ifdef CONFIG_DEBUG_FS
1642 xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL);
1643 if (IS_ERR_OR_NULL(xen_netback_dbg_root))
1644 pr_warn("Init of debugfs returned %ld!\n",
1645 PTR_ERR(xen_netback_dbg_root));
1646 #endif /* CONFIG_DEBUG_FS */
1654 module_init(netback_init);
1656 static void __exit netback_fini(void)
1658 #ifdef CONFIG_DEBUG_FS
1659 if (!IS_ERR_OR_NULL(xen_netback_dbg_root))
1660 debugfs_remove_recursive(xen_netback_dbg_root);
1661 #endif /* CONFIG_DEBUG_FS */
1662 xenvif_xenbus_fini();
1664 module_exit(netback_fini);
1666 MODULE_LICENSE("Dual BSD/GPL");
1667 MODULE_ALIAS("xen-backend:vif");