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>
42 #include <net/ip6_checksum.h>
45 #include <xen/events.h>
46 #include <xen/interface/memory.h>
48 #include <asm/xen/hypercall.h>
49 #include <asm/xen/page.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 = 1;
56 module_param(separate_tx_rx_irq, bool, 0644);
59 * This is the maximum slots a skb can have. If a guest sends a skb
60 * which exceeds this limit it is considered malicious.
62 #define FATAL_SKB_SLOTS_DEFAULT 20
63 static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT;
64 module_param(fatal_skb_slots, uint, 0444);
67 * To avoid confusion, we define XEN_NETBK_LEGACY_SLOTS_MAX indicating
68 * the maximum slots a valid packet can use. Now this value is defined
69 * to be XEN_NETIF_NR_SLOTS_MIN, which is supposed to be supported by
72 #define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN
75 * If head != INVALID_PENDING_RING_IDX, it means this tx request is head of
76 * one or more merged tx requests, otherwise it is the continuation of
77 * previous tx request.
79 static inline int pending_tx_is_head(struct xenvif *vif, RING_IDX idx)
81 return vif->pending_tx_info[idx].head != INVALID_PENDING_RING_IDX;
84 static void xenvif_idx_release(struct xenvif *vif, u16 pending_idx,
87 static void make_tx_response(struct xenvif *vif,
88 struct xen_netif_tx_request *txp,
91 static inline int tx_work_todo(struct xenvif *vif);
92 static inline int rx_work_todo(struct xenvif *vif);
94 static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif,
101 static inline unsigned long idx_to_pfn(struct xenvif *vif,
104 return page_to_pfn(vif->mmap_pages[idx]);
107 static inline unsigned long idx_to_kaddr(struct xenvif *vif,
110 return (unsigned long)pfn_to_kaddr(idx_to_pfn(vif, idx));
113 /* This is a miniumum size for the linear area to avoid lots of
114 * calls to __pskb_pull_tail() as we set up checksum offsets. The
115 * value 128 was chosen as it covers all IPv4 and most likely
118 #define PKT_PROT_LEN 128
120 static u16 frag_get_pending_idx(skb_frag_t *frag)
122 return (u16)frag->page_offset;
125 static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx)
127 frag->page_offset = pending_idx;
130 static inline pending_ring_idx_t pending_index(unsigned i)
132 return i & (MAX_PENDING_REQS-1);
135 static inline pending_ring_idx_t nr_pending_reqs(struct xenvif *vif)
137 return MAX_PENDING_REQS -
138 vif->pending_prod + vif->pending_cons;
141 bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed)
146 prod = vif->rx.sring->req_prod;
147 cons = vif->rx.req_cons;
149 if (prod - cons >= needed)
152 vif->rx.sring->req_event = prod + 1;
154 /* Make sure event is visible before we check prod
158 } while (vif->rx.sring->req_prod != prod);
164 * Returns true if we should start a new receive buffer instead of
165 * adding 'size' bytes to a buffer which currently contains 'offset'
168 static bool start_new_rx_buffer(int offset, unsigned long size, int head)
170 /* simple case: we have completely filled the current buffer. */
171 if (offset == MAX_BUFFER_OFFSET)
175 * complex case: start a fresh buffer if the current frag
176 * would overflow the current buffer but only if:
177 * (i) this frag would fit completely in the next buffer
178 * and (ii) there is already some data in the current buffer
179 * and (iii) this is not the head buffer.
182 * - (i) stops us splitting a frag into two copies
183 * unless the frag is too large for a single buffer.
184 * - (ii) stops us from leaving a buffer pointlessly empty.
185 * - (iii) stops us leaving the first buffer
186 * empty. Strictly speaking this is already covered
187 * by (ii) but is explicitly checked because
188 * netfront relies on the first buffer being
189 * non-empty and can crash otherwise.
191 * This means we will effectively linearise small
192 * frags but do not needlessly split large buffers
193 * into multiple copies tend to give large frags their
194 * own buffers as before.
196 if ((offset + size > MAX_BUFFER_OFFSET) &&
197 (size <= MAX_BUFFER_OFFSET) && offset && !head)
203 struct netrx_pending_operations {
204 unsigned copy_prod, copy_cons;
205 unsigned meta_prod, meta_cons;
206 struct gnttab_copy *copy;
207 struct xenvif_rx_meta *meta;
209 grant_ref_t copy_gref;
212 static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif *vif,
213 struct netrx_pending_operations *npo)
215 struct xenvif_rx_meta *meta;
216 struct xen_netif_rx_request *req;
218 req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
220 meta = npo->meta + npo->meta_prod++;
221 meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
227 npo->copy_gref = req->gref;
233 * Set up the grant operations for this fragment. If it's a flipping
234 * interface, we also set up the unmap request from here.
236 static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb,
237 struct netrx_pending_operations *npo,
238 struct page *page, unsigned long size,
239 unsigned long offset, int *head)
241 struct gnttab_copy *copy_gop;
242 struct xenvif_rx_meta *meta;
246 /* Data must not cross a page boundary. */
247 BUG_ON(size + offset > PAGE_SIZE<<compound_order(page));
249 meta = npo->meta + npo->meta_prod - 1;
251 /* Skip unused frames from start of page */
252 page += offset >> PAGE_SHIFT;
253 offset &= ~PAGE_MASK;
256 BUG_ON(offset >= PAGE_SIZE);
257 BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET);
259 bytes = PAGE_SIZE - offset;
264 if (start_new_rx_buffer(npo->copy_off, bytes, *head)) {
266 * Netfront requires there to be some data in the head
271 meta = get_next_rx_buffer(vif, npo);
274 if (npo->copy_off + bytes > MAX_BUFFER_OFFSET)
275 bytes = MAX_BUFFER_OFFSET - npo->copy_off;
277 copy_gop = npo->copy + npo->copy_prod++;
278 copy_gop->flags = GNTCOPY_dest_gref;
279 copy_gop->len = bytes;
281 copy_gop->source.domid = DOMID_SELF;
282 copy_gop->source.u.gmfn = virt_to_mfn(page_address(page));
283 copy_gop->source.offset = offset;
285 copy_gop->dest.domid = vif->domid;
286 copy_gop->dest.offset = npo->copy_off;
287 copy_gop->dest.u.ref = npo->copy_gref;
289 npo->copy_off += bytes;
296 if (offset == PAGE_SIZE && size) {
297 BUG_ON(!PageCompound(page));
302 /* Leave a gap for the GSO descriptor. */
303 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
304 gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
305 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
306 gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
308 gso_type = XEN_NETIF_GSO_TYPE_NONE;
310 if (*head && ((1 << gso_type) & vif->gso_mask))
313 *head = 0; /* There must be something in this buffer now. */
319 * Prepare an SKB to be transmitted to the frontend.
321 * This function is responsible for allocating grant operations, meta
324 * It returns the number of meta structures consumed. The number of
325 * ring slots used is always equal to the number of meta slots used
326 * plus the number of GSO descriptors used. Currently, we use either
327 * zero GSO descriptors (for non-GSO packets) or one descriptor (for
328 * frontend-side LRO).
330 static int xenvif_gop_skb(struct sk_buff *skb,
331 struct netrx_pending_operations *npo)
333 struct xenvif *vif = netdev_priv(skb->dev);
334 int nr_frags = skb_shinfo(skb)->nr_frags;
336 struct xen_netif_rx_request *req;
337 struct xenvif_rx_meta *meta;
344 old_meta_prod = npo->meta_prod;
346 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
347 gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
348 gso_size = skb_shinfo(skb)->gso_size;
349 } else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) {
350 gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
351 gso_size = skb_shinfo(skb)->gso_size;
353 gso_type = XEN_NETIF_GSO_TYPE_NONE;
357 /* Set up a GSO prefix descriptor, if necessary */
358 if ((1 << skb_shinfo(skb)->gso_type) & vif->gso_prefix_mask) {
359 req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
360 meta = npo->meta + npo->meta_prod++;
361 meta->gso_type = gso_type;
362 meta->gso_size = gso_size;
367 req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
368 meta = npo->meta + npo->meta_prod++;
370 if ((1 << gso_type) & vif->gso_mask) {
371 meta->gso_type = gso_type;
372 meta->gso_size = gso_size;
374 meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
381 npo->copy_gref = req->gref;
384 while (data < skb_tail_pointer(skb)) {
385 unsigned int offset = offset_in_page(data);
386 unsigned int len = PAGE_SIZE - offset;
388 if (data + len > skb_tail_pointer(skb))
389 len = skb_tail_pointer(skb) - data;
391 xenvif_gop_frag_copy(vif, skb, npo,
392 virt_to_page(data), len, offset, &head);
396 for (i = 0; i < nr_frags; i++) {
397 xenvif_gop_frag_copy(vif, skb, npo,
398 skb_frag_page(&skb_shinfo(skb)->frags[i]),
399 skb_frag_size(&skb_shinfo(skb)->frags[i]),
400 skb_shinfo(skb)->frags[i].page_offset,
404 return npo->meta_prod - old_meta_prod;
408 * This is a twin to xenvif_gop_skb. Assume that xenvif_gop_skb was
409 * used to set up the operations on the top of
410 * netrx_pending_operations, which have since been done. Check that
411 * they didn't give any errors and advance over them.
413 static int xenvif_check_gop(struct xenvif *vif, int nr_meta_slots,
414 struct netrx_pending_operations *npo)
416 struct gnttab_copy *copy_op;
417 int status = XEN_NETIF_RSP_OKAY;
420 for (i = 0; i < nr_meta_slots; i++) {
421 copy_op = npo->copy + npo->copy_cons++;
422 if (copy_op->status != GNTST_okay) {
424 "Bad status %d from copy to DOM%d.\n",
425 copy_op->status, vif->domid);
426 status = XEN_NETIF_RSP_ERROR;
433 static void xenvif_add_frag_responses(struct xenvif *vif, int status,
434 struct xenvif_rx_meta *meta,
438 unsigned long offset;
440 /* No fragments used */
441 if (nr_meta_slots <= 1)
446 for (i = 0; i < nr_meta_slots; i++) {
448 if (i == nr_meta_slots - 1)
451 flags = XEN_NETRXF_more_data;
454 make_rx_response(vif, meta[i].id, status, offset,
455 meta[i].size, flags);
459 struct skb_cb_overlay {
463 void xenvif_kick_thread(struct xenvif *vif)
468 static void xenvif_rx_action(struct xenvif *vif)
472 struct xen_netif_rx_response *resp;
473 struct sk_buff_head rxq;
477 unsigned long offset;
478 struct skb_cb_overlay *sco;
479 int need_to_notify = 0;
481 struct netrx_pending_operations npo = {
482 .copy = vif->grant_copy_op,
486 skb_queue_head_init(&rxq);
488 while ((skb = skb_dequeue(&vif->rx_queue)) != NULL) {
489 int max_slots_needed;
492 /* We need a cheap worse case estimate for the number of
496 max_slots_needed = DIV_ROUND_UP(offset_in_page(skb->data) +
499 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
501 size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
502 max_slots_needed += DIV_ROUND_UP(size, PAGE_SIZE);
504 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4 ||
505 skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
508 /* If the skb may not fit then bail out now */
509 if (!xenvif_rx_ring_slots_available(vif, max_slots_needed)) {
510 skb_queue_head(&vif->rx_queue, skb);
515 sco = (struct skb_cb_overlay *)skb->cb;
516 sco->meta_slots_used = xenvif_gop_skb(skb, &npo);
517 BUG_ON(sco->meta_slots_used > max_slots_needed);
519 __skb_queue_tail(&rxq, skb);
522 BUG_ON(npo.meta_prod > ARRAY_SIZE(vif->meta));
527 BUG_ON(npo.copy_prod > ARRAY_SIZE(vif->grant_copy_op));
528 gnttab_batch_copy(vif->grant_copy_op, npo.copy_prod);
530 while ((skb = __skb_dequeue(&rxq)) != NULL) {
531 sco = (struct skb_cb_overlay *)skb->cb;
533 if ((1 << vif->meta[npo.meta_cons].gso_type) &
534 vif->gso_prefix_mask) {
535 resp = RING_GET_RESPONSE(&vif->rx,
536 vif->rx.rsp_prod_pvt++);
538 resp->flags = XEN_NETRXF_gso_prefix | XEN_NETRXF_more_data;
540 resp->offset = vif->meta[npo.meta_cons].gso_size;
541 resp->id = vif->meta[npo.meta_cons].id;
542 resp->status = sco->meta_slots_used;
545 sco->meta_slots_used--;
549 vif->dev->stats.tx_bytes += skb->len;
550 vif->dev->stats.tx_packets++;
552 status = xenvif_check_gop(vif, sco->meta_slots_used, &npo);
554 if (sco->meta_slots_used == 1)
557 flags = XEN_NETRXF_more_data;
559 if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */
560 flags |= XEN_NETRXF_csum_blank | XEN_NETRXF_data_validated;
561 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
562 /* remote but checksummed. */
563 flags |= XEN_NETRXF_data_validated;
566 resp = make_rx_response(vif, vif->meta[npo.meta_cons].id,
568 vif->meta[npo.meta_cons].size,
571 if ((1 << vif->meta[npo.meta_cons].gso_type) &
573 struct xen_netif_extra_info *gso =
574 (struct xen_netif_extra_info *)
575 RING_GET_RESPONSE(&vif->rx,
576 vif->rx.rsp_prod_pvt++);
578 resp->flags |= XEN_NETRXF_extra_info;
580 gso->u.gso.type = vif->meta[npo.meta_cons].gso_type;
581 gso->u.gso.size = vif->meta[npo.meta_cons].gso_size;
583 gso->u.gso.features = 0;
585 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
589 xenvif_add_frag_responses(vif, status,
590 vif->meta + npo.meta_cons + 1,
591 sco->meta_slots_used);
593 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->rx, ret);
598 npo.meta_cons += sco->meta_slots_used;
604 notify_remote_via_irq(vif->rx_irq);
607 void xenvif_check_rx_xenvif(struct xenvif *vif)
611 RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do);
614 napi_schedule(&vif->napi);
617 static void tx_add_credit(struct xenvif *vif)
619 unsigned long max_burst, max_credit;
622 * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
623 * Otherwise the interface can seize up due to insufficient credit.
625 max_burst = RING_GET_REQUEST(&vif->tx, vif->tx.req_cons)->size;
626 max_burst = min(max_burst, 131072UL);
627 max_burst = max(max_burst, vif->credit_bytes);
629 /* Take care that adding a new chunk of credit doesn't wrap to zero. */
630 max_credit = vif->remaining_credit + vif->credit_bytes;
631 if (max_credit < vif->remaining_credit)
632 max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
634 vif->remaining_credit = min(max_credit, max_burst);
637 static void tx_credit_callback(unsigned long data)
639 struct xenvif *vif = (struct xenvif *)data;
641 xenvif_check_rx_xenvif(vif);
644 static void xenvif_tx_err(struct xenvif *vif,
645 struct xen_netif_tx_request *txp, RING_IDX end)
647 RING_IDX cons = vif->tx.req_cons;
650 make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR);
653 txp = RING_GET_REQUEST(&vif->tx, cons++);
655 vif->tx.req_cons = cons;
658 static void xenvif_fatal_tx_err(struct xenvif *vif)
660 netdev_err(vif->dev, "fatal error; disabling device\n");
661 xenvif_carrier_off(vif);
664 static int xenvif_count_requests(struct xenvif *vif,
665 struct xen_netif_tx_request *first,
666 struct xen_netif_tx_request *txp,
669 RING_IDX cons = vif->tx.req_cons;
674 if (!(first->flags & XEN_NETTXF_more_data))
678 struct xen_netif_tx_request dropped_tx = { 0 };
680 if (slots >= work_to_do) {
682 "Asked for %d slots but exceeds this limit\n",
684 xenvif_fatal_tx_err(vif);
688 /* This guest is really using too many slots and
689 * considered malicious.
691 if (unlikely(slots >= fatal_skb_slots)) {
693 "Malicious frontend using %d slots, threshold %u\n",
694 slots, fatal_skb_slots);
695 xenvif_fatal_tx_err(vif);
699 /* Xen network protocol had implicit dependency on
700 * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to
701 * the historical MAX_SKB_FRAGS value 18 to honor the
702 * same behavior as before. Any packet using more than
703 * 18 slots but less than fatal_skb_slots slots is
706 if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) {
709 "Too many slots (%d) exceeding limit (%d), dropping packet\n",
710 slots, XEN_NETBK_LEGACY_SLOTS_MAX);
717 memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + slots),
720 /* If the guest submitted a frame >= 64 KiB then
721 * first->size overflowed and following slots will
722 * appear to be larger than the frame.
724 * This cannot be fatal error as there are buggy
725 * frontends that do this.
727 * Consume all slots and drop the packet.
729 if (!drop_err && txp->size > first->size) {
732 "Invalid tx request, slot size %u > remaining size %u\n",
733 txp->size, first->size);
737 first->size -= txp->size;
740 if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) {
741 netdev_err(vif->dev, "Cross page boundary, txp->offset: %x, size: %u\n",
742 txp->offset, txp->size);
743 xenvif_fatal_tx_err(vif);
747 more_data = txp->flags & XEN_NETTXF_more_data;
755 xenvif_tx_err(vif, first, cons + slots);
762 static struct page *xenvif_alloc_page(struct xenvif *vif,
767 page = alloc_page(GFP_ATOMIC|__GFP_COLD);
770 vif->mmap_pages[pending_idx] = page;
775 static struct gnttab_copy *xenvif_get_requests(struct xenvif *vif,
777 struct xen_netif_tx_request *txp,
778 struct gnttab_copy *gop)
780 struct skb_shared_info *shinfo = skb_shinfo(skb);
781 skb_frag_t *frags = shinfo->frags;
782 u16 pending_idx = *((u16 *)skb->data);
786 pending_ring_idx_t index, start_idx = 0;
788 unsigned int nr_slots;
789 struct pending_tx_info *first = NULL;
791 /* At this point shinfo->nr_frags is in fact the number of
792 * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
794 nr_slots = shinfo->nr_frags;
796 /* Skip first skb fragment if it is on same page as header fragment. */
797 start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
799 /* Coalesce tx requests, at this point the packet passed in
800 * should be <= 64K. Any packets larger than 64K have been
801 * handled in xenvif_count_requests().
803 for (shinfo->nr_frags = slot = start; slot < nr_slots;
804 shinfo->nr_frags++) {
805 struct pending_tx_info *pending_tx_info =
806 vif->pending_tx_info;
808 page = alloc_page(GFP_ATOMIC|__GFP_COLD);
814 while (dst_offset < PAGE_SIZE && slot < nr_slots) {
815 gop->flags = GNTCOPY_source_gref;
817 gop->source.u.ref = txp->gref;
818 gop->source.domid = vif->domid;
819 gop->source.offset = txp->offset;
821 gop->dest.domid = DOMID_SELF;
823 gop->dest.offset = dst_offset;
824 gop->dest.u.gmfn = virt_to_mfn(page_address(page));
826 if (dst_offset + txp->size > PAGE_SIZE) {
827 /* This page can only merge a portion
828 * of tx request. Do not increment any
829 * pointer / counter here. The txp
830 * will be dealt with in future
831 * rounds, eventually hitting the
834 gop->len = PAGE_SIZE - dst_offset;
835 txp->offset += gop->len;
836 txp->size -= gop->len;
837 dst_offset += gop->len; /* quit loop */
839 /* This tx request can be merged in the page */
840 gop->len = txp->size;
841 dst_offset += gop->len;
843 index = pending_index(vif->pending_cons++);
845 pending_idx = vif->pending_ring[index];
847 memcpy(&pending_tx_info[pending_idx].req, txp,
850 /* Poison these fields, corresponding
851 * fields for head tx req will be set
852 * to correct values after the loop.
854 vif->mmap_pages[pending_idx] = (void *)(~0UL);
855 pending_tx_info[pending_idx].head =
856 INVALID_PENDING_RING_IDX;
859 first = &pending_tx_info[pending_idx];
861 head_idx = pending_idx;
871 first->req.offset = 0;
872 first->req.size = dst_offset;
873 first->head = start_idx;
874 vif->mmap_pages[head_idx] = page;
875 frag_set_pending_idx(&frags[shinfo->nr_frags], head_idx);
878 BUG_ON(shinfo->nr_frags > MAX_SKB_FRAGS);
882 /* Unwind, freeing all pages and sending error responses. */
883 while (shinfo->nr_frags-- > start) {
884 xenvif_idx_release(vif,
885 frag_get_pending_idx(&frags[shinfo->nr_frags]),
886 XEN_NETIF_RSP_ERROR);
888 /* The head too, if necessary. */
890 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR);
895 static int xenvif_tx_check_gop(struct xenvif *vif,
897 struct gnttab_copy **gopp)
899 struct gnttab_copy *gop = *gopp;
900 u16 pending_idx = *((u16 *)skb->data);
901 struct skb_shared_info *shinfo = skb_shinfo(skb);
902 struct pending_tx_info *tx_info;
903 int nr_frags = shinfo->nr_frags;
905 u16 peek; /* peek into next tx request */
907 /* Check status of header. */
910 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR);
912 /* Skip first skb fragment if it is on same page as header fragment. */
913 start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
915 for (i = start; i < nr_frags; i++) {
917 pending_ring_idx_t head;
919 pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
920 tx_info = &vif->pending_tx_info[pending_idx];
921 head = tx_info->head;
923 /* Check error status: if okay then remember grant handle. */
925 newerr = (++gop)->status;
928 peek = vif->pending_ring[pending_index(++head)];
929 } while (!pending_tx_is_head(vif, peek));
931 if (likely(!newerr)) {
932 /* Had a previous error? Invalidate this fragment. */
934 xenvif_idx_release(vif, pending_idx,
939 /* Error on this fragment: respond to client with an error. */
940 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR);
942 /* Not the first error? Preceding frags already invalidated. */
946 /* First error: invalidate header and preceding fragments. */
947 pending_idx = *((u16 *)skb->data);
948 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY);
949 for (j = start; j < i; j++) {
950 pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
951 xenvif_idx_release(vif, pending_idx,
955 /* Remember the error: invalidate all subsequent fragments. */
963 static void xenvif_fill_frags(struct xenvif *vif, struct sk_buff *skb)
965 struct skb_shared_info *shinfo = skb_shinfo(skb);
966 int nr_frags = shinfo->nr_frags;
969 for (i = 0; i < nr_frags; i++) {
970 skb_frag_t *frag = shinfo->frags + i;
971 struct xen_netif_tx_request *txp;
975 pending_idx = frag_get_pending_idx(frag);
977 txp = &vif->pending_tx_info[pending_idx].req;
978 page = virt_to_page(idx_to_kaddr(vif, pending_idx));
979 __skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
980 skb->len += txp->size;
981 skb->data_len += txp->size;
982 skb->truesize += txp->size;
984 /* Take an extra reference to offset xenvif_idx_release */
985 get_page(vif->mmap_pages[pending_idx]);
986 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY);
990 static int xenvif_get_extras(struct xenvif *vif,
991 struct xen_netif_extra_info *extras,
994 struct xen_netif_extra_info extra;
995 RING_IDX cons = vif->tx.req_cons;
998 if (unlikely(work_to_do-- <= 0)) {
999 netdev_err(vif->dev, "Missing extra info\n");
1000 xenvif_fatal_tx_err(vif);
1004 memcpy(&extra, RING_GET_REQUEST(&vif->tx, cons),
1006 if (unlikely(!extra.type ||
1007 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
1008 vif->tx.req_cons = ++cons;
1009 netdev_err(vif->dev,
1010 "Invalid extra type: %d\n", extra.type);
1011 xenvif_fatal_tx_err(vif);
1015 memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
1016 vif->tx.req_cons = ++cons;
1017 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
1022 static int xenvif_set_skb_gso(struct xenvif *vif,
1023 struct sk_buff *skb,
1024 struct xen_netif_extra_info *gso)
1026 if (!gso->u.gso.size) {
1027 netdev_err(vif->dev, "GSO size must not be zero.\n");
1028 xenvif_fatal_tx_err(vif);
1032 switch (gso->u.gso.type) {
1033 case XEN_NETIF_GSO_TYPE_TCPV4:
1034 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1036 case XEN_NETIF_GSO_TYPE_TCPV6:
1037 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1040 netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
1041 xenvif_fatal_tx_err(vif);
1045 skb_shinfo(skb)->gso_size = gso->u.gso.size;
1047 /* Header must be checked, and gso_segs computed. */
1048 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1049 skb_shinfo(skb)->gso_segs = 0;
1054 static inline int maybe_pull_tail(struct sk_buff *skb, unsigned int len,
1057 if (skb_headlen(skb) >= len)
1060 /* If we need to pullup then pullup to the max, so we
1061 * won't need to do it again.
1066 if (__pskb_pull_tail(skb, max - skb_headlen(skb)) == NULL)
1069 if (skb_headlen(skb) < len)
1075 /* This value should be large enough to cover a tagged ethernet header plus
1076 * maximally sized IP and TCP or UDP headers.
1078 #define MAX_IP_HDR_LEN 128
1080 static int checksum_setup_ip(struct xenvif *vif, struct sk_buff *skb,
1081 int recalculate_partial_csum)
1089 err = maybe_pull_tail(skb,
1090 sizeof(struct iphdr),
1095 if (ip_hdr(skb)->frag_off & htons(IP_OFFSET | IP_MF))
1098 off = ip_hdrlen(skb);
1102 switch (ip_hdr(skb)->protocol) {
1104 if (!skb_partial_csum_set(skb, off,
1105 offsetof(struct tcphdr, check)))
1108 if (recalculate_partial_csum) {
1109 err = maybe_pull_tail(skb,
1110 off + sizeof(struct tcphdr),
1115 tcp_hdr(skb)->check =
1116 ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
1123 if (!skb_partial_csum_set(skb, off,
1124 offsetof(struct udphdr, check)))
1127 if (recalculate_partial_csum) {
1128 err = maybe_pull_tail(skb,
1129 off + sizeof(struct udphdr),
1134 udp_hdr(skb)->check =
1135 ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
1151 /* This value should be large enough to cover a tagged ethernet header plus
1152 * an IPv6 header, all options, and a maximal TCP or UDP header.
1154 #define MAX_IPV6_HDR_LEN 256
1156 #define OPT_HDR(type, skb, off) \
1157 (type *)(skb_network_header(skb) + (off))
1159 static int checksum_setup_ipv6(struct xenvif *vif, struct sk_buff *skb,
1160 int recalculate_partial_csum)
1172 off = sizeof(struct ipv6hdr);
1174 err = maybe_pull_tail(skb, off, MAX_IPV6_HDR_LEN);
1178 nexthdr = ipv6_hdr(skb)->nexthdr;
1180 len = sizeof(struct ipv6hdr) + ntohs(ipv6_hdr(skb)->payload_len);
1181 while (off <= len && !done) {
1183 case IPPROTO_DSTOPTS:
1184 case IPPROTO_HOPOPTS:
1185 case IPPROTO_ROUTING: {
1186 struct ipv6_opt_hdr *hp;
1188 err = maybe_pull_tail(skb,
1190 sizeof(struct ipv6_opt_hdr),
1195 hp = OPT_HDR(struct ipv6_opt_hdr, skb, off);
1196 nexthdr = hp->nexthdr;
1197 off += ipv6_optlen(hp);
1201 struct ip_auth_hdr *hp;
1203 err = maybe_pull_tail(skb,
1205 sizeof(struct ip_auth_hdr),
1210 hp = OPT_HDR(struct ip_auth_hdr, skb, off);
1211 nexthdr = hp->nexthdr;
1212 off += ipv6_authlen(hp);
1215 case IPPROTO_FRAGMENT: {
1216 struct frag_hdr *hp;
1218 err = maybe_pull_tail(skb,
1220 sizeof(struct frag_hdr),
1225 hp = OPT_HDR(struct frag_hdr, skb, off);
1227 if (hp->frag_off & htons(IP6_OFFSET | IP6_MF))
1230 nexthdr = hp->nexthdr;
1231 off += sizeof(struct frag_hdr);
1242 if (!done || fragment)
1247 if (!skb_partial_csum_set(skb, off,
1248 offsetof(struct tcphdr, check)))
1251 if (recalculate_partial_csum) {
1252 err = maybe_pull_tail(skb,
1253 off + sizeof(struct tcphdr),
1258 tcp_hdr(skb)->check =
1259 ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
1260 &ipv6_hdr(skb)->daddr,
1266 if (!skb_partial_csum_set(skb, off,
1267 offsetof(struct udphdr, check)))
1270 if (recalculate_partial_csum) {
1271 err = maybe_pull_tail(skb,
1272 off + sizeof(struct udphdr),
1277 udp_hdr(skb)->check =
1278 ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
1279 &ipv6_hdr(skb)->daddr,
1294 static int checksum_setup(struct xenvif *vif, struct sk_buff *skb)
1297 int recalculate_partial_csum = 0;
1299 /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
1300 * peers can fail to set NETRXF_csum_blank when sending a GSO
1301 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
1302 * recalculate the partial checksum.
1304 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
1305 vif->rx_gso_checksum_fixup++;
1306 skb->ip_summed = CHECKSUM_PARTIAL;
1307 recalculate_partial_csum = 1;
1310 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
1311 if (skb->ip_summed != CHECKSUM_PARTIAL)
1314 if (skb->protocol == htons(ETH_P_IP))
1315 err = checksum_setup_ip(vif, skb, recalculate_partial_csum);
1316 else if (skb->protocol == htons(ETH_P_IPV6))
1317 err = checksum_setup_ipv6(vif, skb, recalculate_partial_csum);
1322 static bool tx_credit_exceeded(struct xenvif *vif, unsigned size)
1324 u64 now = get_jiffies_64();
1325 u64 next_credit = vif->credit_window_start +
1326 msecs_to_jiffies(vif->credit_usec / 1000);
1328 /* Timer could already be pending in rare cases. */
1329 if (timer_pending(&vif->credit_timeout))
1332 /* Passed the point where we can replenish credit? */
1333 if (time_after_eq64(now, next_credit)) {
1334 vif->credit_window_start = now;
1338 /* Still too big to send right now? Set a callback. */
1339 if (size > vif->remaining_credit) {
1340 vif->credit_timeout.data =
1342 vif->credit_timeout.function =
1344 mod_timer(&vif->credit_timeout,
1346 vif->credit_window_start = next_credit;
1354 static unsigned xenvif_tx_build_gops(struct xenvif *vif)
1356 struct gnttab_copy *gop = vif->tx_copy_ops, *request_gop;
1357 struct sk_buff *skb;
1360 while ((nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX
1361 < MAX_PENDING_REQS)) {
1362 struct xen_netif_tx_request txreq;
1363 struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
1365 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
1369 unsigned int data_len;
1370 pending_ring_idx_t index;
1372 if (vif->tx.sring->req_prod - vif->tx.req_cons >
1373 XEN_NETIF_TX_RING_SIZE) {
1374 netdev_err(vif->dev,
1375 "Impossible number of requests. "
1376 "req_prod %d, req_cons %d, size %ld\n",
1377 vif->tx.sring->req_prod, vif->tx.req_cons,
1378 XEN_NETIF_TX_RING_SIZE);
1379 xenvif_fatal_tx_err(vif);
1383 RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, work_to_do);
1387 idx = vif->tx.req_cons;
1388 rmb(); /* Ensure that we see the request before we copy it. */
1389 memcpy(&txreq, RING_GET_REQUEST(&vif->tx, idx), sizeof(txreq));
1391 /* Credit-based scheduling. */
1392 if (txreq.size > vif->remaining_credit &&
1393 tx_credit_exceeded(vif, txreq.size))
1396 vif->remaining_credit -= txreq.size;
1399 vif->tx.req_cons = ++idx;
1401 memset(extras, 0, sizeof(extras));
1402 if (txreq.flags & XEN_NETTXF_extra_info) {
1403 work_to_do = xenvif_get_extras(vif, extras,
1405 idx = vif->tx.req_cons;
1406 if (unlikely(work_to_do < 0))
1410 ret = xenvif_count_requests(vif, &txreq, txfrags, work_to_do);
1411 if (unlikely(ret < 0))
1416 if (unlikely(txreq.size < ETH_HLEN)) {
1417 netdev_dbg(vif->dev,
1418 "Bad packet size: %d\n", txreq.size);
1419 xenvif_tx_err(vif, &txreq, idx);
1423 /* No crossing a page as the payload mustn't fragment. */
1424 if (unlikely((txreq.offset + txreq.size) > PAGE_SIZE)) {
1425 netdev_err(vif->dev,
1426 "txreq.offset: %x, size: %u, end: %lu\n",
1427 txreq.offset, txreq.size,
1428 (txreq.offset&~PAGE_MASK) + txreq.size);
1429 xenvif_fatal_tx_err(vif);
1433 index = pending_index(vif->pending_cons);
1434 pending_idx = vif->pending_ring[index];
1436 data_len = (txreq.size > PKT_PROT_LEN &&
1437 ret < XEN_NETBK_LEGACY_SLOTS_MAX) ?
1438 PKT_PROT_LEN : txreq.size;
1440 skb = alloc_skb(data_len + NET_SKB_PAD + NET_IP_ALIGN,
1441 GFP_ATOMIC | __GFP_NOWARN);
1442 if (unlikely(skb == NULL)) {
1443 netdev_dbg(vif->dev,
1444 "Can't allocate a skb in start_xmit.\n");
1445 xenvif_tx_err(vif, &txreq, idx);
1449 /* Packets passed to netif_rx() must have some headroom. */
1450 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
1452 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1453 struct xen_netif_extra_info *gso;
1454 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1456 if (xenvif_set_skb_gso(vif, skb, gso)) {
1457 /* Failure in xenvif_set_skb_gso is fatal. */
1463 /* XXX could copy straight to head */
1464 page = xenvif_alloc_page(vif, pending_idx);
1467 xenvif_tx_err(vif, &txreq, idx);
1471 gop->source.u.ref = txreq.gref;
1472 gop->source.domid = vif->domid;
1473 gop->source.offset = txreq.offset;
1475 gop->dest.u.gmfn = virt_to_mfn(page_address(page));
1476 gop->dest.domid = DOMID_SELF;
1477 gop->dest.offset = txreq.offset;
1479 gop->len = txreq.size;
1480 gop->flags = GNTCOPY_source_gref;
1484 memcpy(&vif->pending_tx_info[pending_idx].req,
1485 &txreq, sizeof(txreq));
1486 vif->pending_tx_info[pending_idx].head = index;
1487 *((u16 *)skb->data) = pending_idx;
1489 __skb_put(skb, data_len);
1491 skb_shinfo(skb)->nr_frags = ret;
1492 if (data_len < txreq.size) {
1493 skb_shinfo(skb)->nr_frags++;
1494 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
1497 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
1498 INVALID_PENDING_IDX);
1501 vif->pending_cons++;
1503 request_gop = xenvif_get_requests(vif, skb, txfrags, gop);
1504 if (request_gop == NULL) {
1506 xenvif_tx_err(vif, &txreq, idx);
1511 __skb_queue_tail(&vif->tx_queue, skb);
1513 vif->tx.req_cons = idx;
1515 if ((gop-vif->tx_copy_ops) >= ARRAY_SIZE(vif->tx_copy_ops))
1519 return gop - vif->tx_copy_ops;
1523 static int xenvif_tx_submit(struct xenvif *vif, int budget)
1525 struct gnttab_copy *gop = vif->tx_copy_ops;
1526 struct sk_buff *skb;
1529 while (work_done < budget &&
1530 (skb = __skb_dequeue(&vif->tx_queue)) != NULL) {
1531 struct xen_netif_tx_request *txp;
1535 pending_idx = *((u16 *)skb->data);
1536 txp = &vif->pending_tx_info[pending_idx].req;
1538 /* Check the remap error code. */
1539 if (unlikely(xenvif_tx_check_gop(vif, skb, &gop))) {
1540 netdev_dbg(vif->dev, "netback grant failed.\n");
1541 skb_shinfo(skb)->nr_frags = 0;
1546 data_len = skb->len;
1548 (void *)(idx_to_kaddr(vif, pending_idx)|txp->offset),
1550 if (data_len < txp->size) {
1551 /* Append the packet payload as a fragment. */
1552 txp->offset += data_len;
1553 txp->size -= data_len;
1555 /* Schedule a response immediately. */
1556 xenvif_idx_release(vif, pending_idx,
1557 XEN_NETIF_RSP_OKAY);
1560 if (txp->flags & XEN_NETTXF_csum_blank)
1561 skb->ip_summed = CHECKSUM_PARTIAL;
1562 else if (txp->flags & XEN_NETTXF_data_validated)
1563 skb->ip_summed = CHECKSUM_UNNECESSARY;
1565 xenvif_fill_frags(vif, skb);
1567 if (skb_is_nonlinear(skb) && skb_headlen(skb) < PKT_PROT_LEN) {
1568 int target = min_t(int, skb->len, PKT_PROT_LEN);
1569 __pskb_pull_tail(skb, target - skb_headlen(skb));
1572 skb->dev = vif->dev;
1573 skb->protocol = eth_type_trans(skb, skb->dev);
1574 skb_reset_network_header(skb);
1576 if (checksum_setup(vif, skb)) {
1577 netdev_dbg(vif->dev,
1578 "Can't setup checksum in net_tx_action\n");
1583 skb_probe_transport_header(skb, 0);
1585 vif->dev->stats.rx_bytes += skb->len;
1586 vif->dev->stats.rx_packets++;
1590 netif_receive_skb(skb);
1596 /* Called after netfront has transmitted */
1597 int xenvif_tx_action(struct xenvif *vif, int budget)
1602 if (unlikely(!tx_work_todo(vif)))
1605 nr_gops = xenvif_tx_build_gops(vif);
1610 gnttab_batch_copy(vif->tx_copy_ops, nr_gops);
1612 work_done = xenvif_tx_submit(vif, nr_gops);
1617 static void xenvif_idx_release(struct xenvif *vif, u16 pending_idx,
1620 struct pending_tx_info *pending_tx_info;
1621 pending_ring_idx_t head;
1622 u16 peek; /* peek into next tx request */
1624 BUG_ON(vif->mmap_pages[pending_idx] == (void *)(~0UL));
1626 /* Already complete? */
1627 if (vif->mmap_pages[pending_idx] == NULL)
1630 pending_tx_info = &vif->pending_tx_info[pending_idx];
1632 head = pending_tx_info->head;
1634 BUG_ON(!pending_tx_is_head(vif, head));
1635 BUG_ON(vif->pending_ring[pending_index(head)] != pending_idx);
1638 pending_ring_idx_t index;
1639 pending_ring_idx_t idx = pending_index(head);
1640 u16 info_idx = vif->pending_ring[idx];
1642 pending_tx_info = &vif->pending_tx_info[info_idx];
1643 make_tx_response(vif, &pending_tx_info->req, status);
1645 /* Setting any number other than
1646 * INVALID_PENDING_RING_IDX indicates this slot is
1647 * starting a new packet / ending a previous packet.
1649 pending_tx_info->head = 0;
1651 index = pending_index(vif->pending_prod++);
1652 vif->pending_ring[index] = vif->pending_ring[info_idx];
1654 peek = vif->pending_ring[pending_index(++head)];
1656 } while (!pending_tx_is_head(vif, peek));
1658 put_page(vif->mmap_pages[pending_idx]);
1659 vif->mmap_pages[pending_idx] = NULL;
1663 static void make_tx_response(struct xenvif *vif,
1664 struct xen_netif_tx_request *txp,
1667 RING_IDX i = vif->tx.rsp_prod_pvt;
1668 struct xen_netif_tx_response *resp;
1671 resp = RING_GET_RESPONSE(&vif->tx, i);
1675 if (txp->flags & XEN_NETTXF_extra_info)
1676 RING_GET_RESPONSE(&vif->tx, ++i)->status = XEN_NETIF_RSP_NULL;
1678 vif->tx.rsp_prod_pvt = ++i;
1679 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->tx, notify);
1681 notify_remote_via_irq(vif->tx_irq);
1684 static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif,
1691 RING_IDX i = vif->rx.rsp_prod_pvt;
1692 struct xen_netif_rx_response *resp;
1694 resp = RING_GET_RESPONSE(&vif->rx, i);
1695 resp->offset = offset;
1696 resp->flags = flags;
1698 resp->status = (s16)size;
1700 resp->status = (s16)st;
1702 vif->rx.rsp_prod_pvt = ++i;
1707 static inline int rx_work_todo(struct xenvif *vif)
1709 return !skb_queue_empty(&vif->rx_queue) || vif->rx_event;
1712 static inline int tx_work_todo(struct xenvif *vif)
1715 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->tx)) &&
1716 (nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX
1717 < MAX_PENDING_REQS))
1723 void xenvif_unmap_frontend_rings(struct xenvif *vif)
1726 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
1729 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
1733 int xenvif_map_frontend_rings(struct xenvif *vif,
1734 grant_ref_t tx_ring_ref,
1735 grant_ref_t rx_ring_ref)
1738 struct xen_netif_tx_sring *txs;
1739 struct xen_netif_rx_sring *rxs;
1743 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
1744 tx_ring_ref, &addr);
1748 txs = (struct xen_netif_tx_sring *)addr;
1749 BACK_RING_INIT(&vif->tx, txs, PAGE_SIZE);
1751 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
1752 rx_ring_ref, &addr);
1756 rxs = (struct xen_netif_rx_sring *)addr;
1757 BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE);
1762 xenvif_unmap_frontend_rings(vif);
1766 void xenvif_stop_queue(struct xenvif *vif)
1768 if (!vif->can_queue)
1771 netif_stop_queue(vif->dev);
1774 static void xenvif_start_queue(struct xenvif *vif)
1776 if (xenvif_schedulable(vif))
1777 netif_wake_queue(vif->dev);
1780 int xenvif_kthread(void *data)
1782 struct xenvif *vif = data;
1783 struct sk_buff *skb;
1785 while (!kthread_should_stop()) {
1786 wait_event_interruptible(vif->wq,
1787 rx_work_todo(vif) ||
1788 kthread_should_stop());
1789 if (kthread_should_stop())
1792 if (!skb_queue_empty(&vif->rx_queue))
1793 xenvif_rx_action(vif);
1795 vif->rx_event = false;
1797 if (skb_queue_empty(&vif->rx_queue) &&
1798 netif_queue_stopped(vif->dev))
1799 xenvif_start_queue(vif);
1804 /* Bin any remaining skbs */
1805 while ((skb = skb_dequeue(&vif->rx_queue)) != NULL)
1811 static int __init netback_init(void)
1818 if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
1819 pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
1820 fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX);
1821 fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX;
1824 rc = xenvif_xenbus_init();
1834 module_init(netback_init);
1836 static void __exit netback_fini(void)
1838 xenvif_xenbus_fini();
1840 module_exit(netback_fini);
1842 MODULE_LICENSE("Dual BSD/GPL");
1843 MODULE_ALIAS("xen-backend:vif");