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 static int max_required_rx_slots(struct xenvif *vif)
143 int max = DIV_ROUND_UP(vif->dev->mtu, PAGE_SIZE);
145 /* XXX FIXME: RX path dependent on MAX_SKB_FRAGS */
146 if (vif->can_sg || vif->gso_mask || vif->gso_prefix_mask)
147 max += MAX_SKB_FRAGS + 1; /* extra_info + frags */
152 int xenvif_rx_ring_full(struct xenvif *vif)
154 RING_IDX peek = vif->rx_req_cons_peek;
155 RING_IDX needed = max_required_rx_slots(vif);
157 return ((vif->rx.sring->req_prod - peek) < needed) ||
158 ((vif->rx.rsp_prod_pvt + XEN_NETIF_RX_RING_SIZE - peek) < needed);
161 int xenvif_must_stop_queue(struct xenvif *vif)
163 if (!xenvif_rx_ring_full(vif))
166 vif->rx.sring->req_event = vif->rx_req_cons_peek +
167 max_required_rx_slots(vif);
168 mb(); /* request notification /then/ check the queue */
170 return xenvif_rx_ring_full(vif);
174 * Returns true if we should start a new receive buffer instead of
175 * adding 'size' bytes to a buffer which currently contains 'offset'
178 static bool start_new_rx_buffer(int offset, unsigned long size, int head)
180 /* simple case: we have completely filled the current buffer. */
181 if (offset == MAX_BUFFER_OFFSET)
185 * complex case: start a fresh buffer if the current frag
186 * would overflow the current buffer but only if:
187 * (i) this frag would fit completely in the next buffer
188 * and (ii) there is already some data in the current buffer
189 * and (iii) this is not the head buffer.
192 * - (i) stops us splitting a frag into two copies
193 * unless the frag is too large for a single buffer.
194 * - (ii) stops us from leaving a buffer pointlessly empty.
195 * - (iii) stops us leaving the first buffer
196 * empty. Strictly speaking this is already covered
197 * by (ii) but is explicitly checked because
198 * netfront relies on the first buffer being
199 * non-empty and can crash otherwise.
201 * This means we will effectively linearise small
202 * frags but do not needlessly split large buffers
203 * into multiple copies tend to give large frags their
204 * own buffers as before.
206 if ((offset + size > MAX_BUFFER_OFFSET) &&
207 (size <= MAX_BUFFER_OFFSET) && offset && !head)
213 struct xenvif_count_slot_state {
214 unsigned long copy_off;
218 unsigned int xenvif_count_frag_slots(struct xenvif *vif,
219 unsigned long offset, unsigned long size,
220 struct xenvif_count_slot_state *state)
224 offset &= ~PAGE_MASK;
229 bytes = PAGE_SIZE - offset;
234 if (start_new_rx_buffer(state->copy_off, bytes, state->head)) {
239 if (state->copy_off + bytes > MAX_BUFFER_OFFSET)
240 bytes = MAX_BUFFER_OFFSET - state->copy_off;
242 state->copy_off += bytes;
247 if (offset == PAGE_SIZE)
257 * Figure out how many ring slots we're going to need to send @skb to
258 * the guest. This function is essentially a dry run of
259 * xenvif_gop_frag_copy.
261 unsigned int xenvif_count_skb_slots(struct xenvif *vif, struct sk_buff *skb)
263 struct xenvif_count_slot_state state;
271 /* Slot for the first (partial) page of data. */
274 /* Need a slot for the GSO prefix for GSO extra data? */
275 if (skb_shinfo(skb)->gso_size)
279 while (data < skb_tail_pointer(skb)) {
280 unsigned long offset = offset_in_page(data);
281 unsigned long size = PAGE_SIZE - offset;
283 if (data + size > skb_tail_pointer(skb))
284 size = skb_tail_pointer(skb) - data;
286 count += xenvif_count_frag_slots(vif, offset, size, &state);
291 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
292 unsigned long size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
293 unsigned long offset = skb_shinfo(skb)->frags[i].page_offset;
295 count += xenvif_count_frag_slots(vif, offset, size, &state);
300 struct netrx_pending_operations {
301 unsigned copy_prod, copy_cons;
302 unsigned meta_prod, meta_cons;
303 struct gnttab_copy *copy;
304 struct xenvif_rx_meta *meta;
306 grant_ref_t copy_gref;
309 static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif *vif,
310 struct netrx_pending_operations *npo)
312 struct xenvif_rx_meta *meta;
313 struct xen_netif_rx_request *req;
315 req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
317 meta = npo->meta + npo->meta_prod++;
318 meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
324 npo->copy_gref = req->gref;
330 * Set up the grant operations for this fragment. If it's a flipping
331 * interface, we also set up the unmap request from here.
333 static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb,
334 struct netrx_pending_operations *npo,
335 struct page *page, unsigned long size,
336 unsigned long offset, int *head)
338 struct gnttab_copy *copy_gop;
339 struct xenvif_rx_meta *meta;
343 /* Data must not cross a page boundary. */
344 BUG_ON(size + offset > PAGE_SIZE<<compound_order(page));
346 meta = npo->meta + npo->meta_prod - 1;
348 /* Skip unused frames from start of page */
349 page += offset >> PAGE_SHIFT;
350 offset &= ~PAGE_MASK;
353 BUG_ON(offset >= PAGE_SIZE);
354 BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET);
356 bytes = PAGE_SIZE - offset;
361 if (start_new_rx_buffer(npo->copy_off, bytes, *head)) {
363 * Netfront requires there to be some data in the head
368 meta = get_next_rx_buffer(vif, npo);
371 if (npo->copy_off + bytes > MAX_BUFFER_OFFSET)
372 bytes = MAX_BUFFER_OFFSET - npo->copy_off;
374 copy_gop = npo->copy + npo->copy_prod++;
375 copy_gop->flags = GNTCOPY_dest_gref;
376 copy_gop->len = bytes;
378 copy_gop->source.domid = DOMID_SELF;
379 copy_gop->source.u.gmfn = virt_to_mfn(page_address(page));
380 copy_gop->source.offset = offset;
382 copy_gop->dest.domid = vif->domid;
383 copy_gop->dest.offset = npo->copy_off;
384 copy_gop->dest.u.ref = npo->copy_gref;
386 npo->copy_off += bytes;
393 if (offset == PAGE_SIZE && size) {
394 BUG_ON(!PageCompound(page));
399 /* Leave a gap for the GSO descriptor. */
400 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
401 gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
402 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
403 gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
405 gso_type = XEN_NETIF_GSO_TYPE_NONE;
407 if (*head && ((1 << gso_type) & vif->gso_mask))
410 *head = 0; /* There must be something in this buffer now. */
416 * Prepare an SKB to be transmitted to the frontend.
418 * This function is responsible for allocating grant operations, meta
421 * It returns the number of meta structures consumed. The number of
422 * ring slots used is always equal to the number of meta slots used
423 * plus the number of GSO descriptors used. Currently, we use either
424 * zero GSO descriptors (for non-GSO packets) or one descriptor (for
425 * frontend-side LRO).
427 static int xenvif_gop_skb(struct sk_buff *skb,
428 struct netrx_pending_operations *npo)
430 struct xenvif *vif = netdev_priv(skb->dev);
431 int nr_frags = skb_shinfo(skb)->nr_frags;
433 struct xen_netif_rx_request *req;
434 struct xenvif_rx_meta *meta;
441 old_meta_prod = npo->meta_prod;
443 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
444 gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
445 gso_size = skb_shinfo(skb)->gso_size;
446 } else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) {
447 gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
448 gso_size = skb_shinfo(skb)->gso_size;
450 gso_type = XEN_NETIF_GSO_TYPE_NONE;
454 /* Set up a GSO prefix descriptor, if necessary */
455 if ((1 << gso_type) & vif->gso_prefix_mask) {
456 req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
457 meta = npo->meta + npo->meta_prod++;
458 meta->gso_type = gso_type;
459 meta->gso_size = gso_size;
464 req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
465 meta = npo->meta + npo->meta_prod++;
467 if ((1 << gso_type) & vif->gso_mask) {
468 meta->gso_type = gso_type;
469 meta->gso_size = gso_size;
471 meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
478 npo->copy_gref = req->gref;
481 while (data < skb_tail_pointer(skb)) {
482 unsigned int offset = offset_in_page(data);
483 unsigned int len = PAGE_SIZE - offset;
485 if (data + len > skb_tail_pointer(skb))
486 len = skb_tail_pointer(skb) - data;
488 xenvif_gop_frag_copy(vif, skb, npo,
489 virt_to_page(data), len, offset, &head);
493 for (i = 0; i < nr_frags; i++) {
494 xenvif_gop_frag_copy(vif, skb, npo,
495 skb_frag_page(&skb_shinfo(skb)->frags[i]),
496 skb_frag_size(&skb_shinfo(skb)->frags[i]),
497 skb_shinfo(skb)->frags[i].page_offset,
501 return npo->meta_prod - old_meta_prod;
505 * This is a twin to xenvif_gop_skb. Assume that xenvif_gop_skb was
506 * used to set up the operations on the top of
507 * netrx_pending_operations, which have since been done. Check that
508 * they didn't give any errors and advance over them.
510 static int xenvif_check_gop(struct xenvif *vif, int nr_meta_slots,
511 struct netrx_pending_operations *npo)
513 struct gnttab_copy *copy_op;
514 int status = XEN_NETIF_RSP_OKAY;
517 for (i = 0; i < nr_meta_slots; i++) {
518 copy_op = npo->copy + npo->copy_cons++;
519 if (copy_op->status != GNTST_okay) {
521 "Bad status %d from copy to DOM%d.\n",
522 copy_op->status, vif->domid);
523 status = XEN_NETIF_RSP_ERROR;
530 static void xenvif_add_frag_responses(struct xenvif *vif, int status,
531 struct xenvif_rx_meta *meta,
535 unsigned long offset;
537 /* No fragments used */
538 if (nr_meta_slots <= 1)
543 for (i = 0; i < nr_meta_slots; i++) {
545 if (i == nr_meta_slots - 1)
548 flags = XEN_NETRXF_more_data;
551 make_rx_response(vif, meta[i].id, status, offset,
552 meta[i].size, flags);
556 struct skb_cb_overlay {
560 static void xenvif_kick_thread(struct xenvif *vif)
565 void xenvif_rx_action(struct xenvif *vif)
569 struct xen_netif_rx_response *resp;
570 struct sk_buff_head rxq;
576 unsigned long offset;
577 struct skb_cb_overlay *sco;
578 int need_to_notify = 0;
580 struct netrx_pending_operations npo = {
581 .copy = vif->grant_copy_op,
585 skb_queue_head_init(&rxq);
589 while ((skb = skb_dequeue(&vif->rx_queue)) != NULL) {
590 vif = netdev_priv(skb->dev);
591 nr_frags = skb_shinfo(skb)->nr_frags;
593 sco = (struct skb_cb_overlay *)skb->cb;
594 sco->meta_slots_used = xenvif_gop_skb(skb, &npo);
596 count += nr_frags + 1;
598 __skb_queue_tail(&rxq, skb);
600 /* Filled the batch queue? */
601 /* XXX FIXME: RX path dependent on MAX_SKB_FRAGS */
602 if (count + MAX_SKB_FRAGS >= XEN_NETIF_RX_RING_SIZE)
606 BUG_ON(npo.meta_prod > ARRAY_SIZE(vif->meta));
611 BUG_ON(npo.copy_prod > MAX_GRANT_COPY_OPS);
612 gnttab_batch_copy(vif->grant_copy_op, npo.copy_prod);
614 while ((skb = __skb_dequeue(&rxq)) != NULL) {
615 sco = (struct skb_cb_overlay *)skb->cb;
617 vif = netdev_priv(skb->dev);
619 if ((1 << vif->meta[npo.meta_cons].gso_type) &
620 vif->gso_prefix_mask) {
621 resp = RING_GET_RESPONSE(&vif->rx,
622 vif->rx.rsp_prod_pvt++);
624 resp->flags = XEN_NETRXF_gso_prefix | XEN_NETRXF_more_data;
626 resp->offset = vif->meta[npo.meta_cons].gso_size;
627 resp->id = vif->meta[npo.meta_cons].id;
628 resp->status = sco->meta_slots_used;
631 sco->meta_slots_used--;
635 vif->dev->stats.tx_bytes += skb->len;
636 vif->dev->stats.tx_packets++;
638 status = xenvif_check_gop(vif, sco->meta_slots_used, &npo);
640 if (sco->meta_slots_used == 1)
643 flags = XEN_NETRXF_more_data;
645 if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */
646 flags |= XEN_NETRXF_csum_blank | XEN_NETRXF_data_validated;
647 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
648 /* remote but checksummed. */
649 flags |= XEN_NETRXF_data_validated;
652 resp = make_rx_response(vif, vif->meta[npo.meta_cons].id,
654 vif->meta[npo.meta_cons].size,
657 if ((1 << vif->meta[npo.meta_cons].gso_type) &
659 struct xen_netif_extra_info *gso =
660 (struct xen_netif_extra_info *)
661 RING_GET_RESPONSE(&vif->rx,
662 vif->rx.rsp_prod_pvt++);
664 resp->flags |= XEN_NETRXF_extra_info;
666 gso->u.gso.type = vif->meta[npo.meta_cons].gso_type;
667 gso->u.gso.size = vif->meta[npo.meta_cons].gso_size;
669 gso->u.gso.features = 0;
671 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
675 xenvif_add_frag_responses(vif, status,
676 vif->meta + npo.meta_cons + 1,
677 sco->meta_slots_used);
679 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->rx, ret);
684 xenvif_notify_tx_completion(vif);
686 npo.meta_cons += sco->meta_slots_used;
691 notify_remote_via_irq(vif->rx_irq);
693 /* More work to do? */
694 if (!skb_queue_empty(&vif->rx_queue))
695 xenvif_kick_thread(vif);
698 void xenvif_queue_tx_skb(struct xenvif *vif, struct sk_buff *skb)
700 skb_queue_tail(&vif->rx_queue, skb);
702 xenvif_kick_thread(vif);
705 void xenvif_check_rx_xenvif(struct xenvif *vif)
709 RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do);
712 napi_schedule(&vif->napi);
715 static void tx_add_credit(struct xenvif *vif)
717 unsigned long max_burst, max_credit;
720 * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
721 * Otherwise the interface can seize up due to insufficient credit.
723 max_burst = RING_GET_REQUEST(&vif->tx, vif->tx.req_cons)->size;
724 max_burst = min(max_burst, 131072UL);
725 max_burst = max(max_burst, vif->credit_bytes);
727 /* Take care that adding a new chunk of credit doesn't wrap to zero. */
728 max_credit = vif->remaining_credit + vif->credit_bytes;
729 if (max_credit < vif->remaining_credit)
730 max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
732 vif->remaining_credit = min(max_credit, max_burst);
735 static void tx_credit_callback(unsigned long data)
737 struct xenvif *vif = (struct xenvif *)data;
739 xenvif_check_rx_xenvif(vif);
742 static void xenvif_tx_err(struct xenvif *vif,
743 struct xen_netif_tx_request *txp, RING_IDX end)
745 RING_IDX cons = vif->tx.req_cons;
748 make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR);
751 txp = RING_GET_REQUEST(&vif->tx, cons++);
753 vif->tx.req_cons = cons;
756 static void xenvif_fatal_tx_err(struct xenvif *vif)
758 netdev_err(vif->dev, "fatal error; disabling device\n");
759 xenvif_carrier_off(vif);
762 static int xenvif_count_requests(struct xenvif *vif,
763 struct xen_netif_tx_request *first,
764 struct xen_netif_tx_request *txp,
767 RING_IDX cons = vif->tx.req_cons;
772 if (!(first->flags & XEN_NETTXF_more_data))
776 struct xen_netif_tx_request dropped_tx = { 0 };
778 if (slots >= work_to_do) {
780 "Asked for %d slots but exceeds this limit\n",
782 xenvif_fatal_tx_err(vif);
786 /* This guest is really using too many slots and
787 * considered malicious.
789 if (unlikely(slots >= fatal_skb_slots)) {
791 "Malicious frontend using %d slots, threshold %u\n",
792 slots, fatal_skb_slots);
793 xenvif_fatal_tx_err(vif);
797 /* Xen network protocol had implicit dependency on
798 * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to
799 * the historical MAX_SKB_FRAGS value 18 to honor the
800 * same behavior as before. Any packet using more than
801 * 18 slots but less than fatal_skb_slots slots is
804 if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) {
807 "Too many slots (%d) exceeding limit (%d), dropping packet\n",
808 slots, XEN_NETBK_LEGACY_SLOTS_MAX);
815 memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + slots),
818 /* If the guest submitted a frame >= 64 KiB then
819 * first->size overflowed and following slots will
820 * appear to be larger than the frame.
822 * This cannot be fatal error as there are buggy
823 * frontends that do this.
825 * Consume all slots and drop the packet.
827 if (!drop_err && txp->size > first->size) {
830 "Invalid tx request, slot size %u > remaining size %u\n",
831 txp->size, first->size);
835 first->size -= txp->size;
838 if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) {
839 netdev_err(vif->dev, "Cross page boundary, txp->offset: %x, size: %u\n",
840 txp->offset, txp->size);
841 xenvif_fatal_tx_err(vif);
845 more_data = txp->flags & XEN_NETTXF_more_data;
853 xenvif_tx_err(vif, first, cons + slots);
860 static struct page *xenvif_alloc_page(struct xenvif *vif,
865 page = alloc_page(GFP_ATOMIC|__GFP_COLD);
868 vif->mmap_pages[pending_idx] = page;
873 static struct gnttab_copy *xenvif_get_requests(struct xenvif *vif,
875 struct xen_netif_tx_request *txp,
876 struct gnttab_copy *gop)
878 struct skb_shared_info *shinfo = skb_shinfo(skb);
879 skb_frag_t *frags = shinfo->frags;
880 u16 pending_idx = *((u16 *)skb->data);
884 pending_ring_idx_t index, start_idx = 0;
886 unsigned int nr_slots;
887 struct pending_tx_info *first = NULL;
889 /* At this point shinfo->nr_frags is in fact the number of
890 * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
892 nr_slots = shinfo->nr_frags;
894 /* Skip first skb fragment if it is on same page as header fragment. */
895 start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
897 /* Coalesce tx requests, at this point the packet passed in
898 * should be <= 64K. Any packets larger than 64K have been
899 * handled in xenvif_count_requests().
901 for (shinfo->nr_frags = slot = start; slot < nr_slots;
902 shinfo->nr_frags++) {
903 struct pending_tx_info *pending_tx_info =
904 vif->pending_tx_info;
906 page = alloc_page(GFP_ATOMIC|__GFP_COLD);
912 while (dst_offset < PAGE_SIZE && slot < nr_slots) {
913 gop->flags = GNTCOPY_source_gref;
915 gop->source.u.ref = txp->gref;
916 gop->source.domid = vif->domid;
917 gop->source.offset = txp->offset;
919 gop->dest.domid = DOMID_SELF;
921 gop->dest.offset = dst_offset;
922 gop->dest.u.gmfn = virt_to_mfn(page_address(page));
924 if (dst_offset + txp->size > PAGE_SIZE) {
925 /* This page can only merge a portion
926 * of tx request. Do not increment any
927 * pointer / counter here. The txp
928 * will be dealt with in future
929 * rounds, eventually hitting the
932 gop->len = PAGE_SIZE - dst_offset;
933 txp->offset += gop->len;
934 txp->size -= gop->len;
935 dst_offset += gop->len; /* quit loop */
937 /* This tx request can be merged in the page */
938 gop->len = txp->size;
939 dst_offset += gop->len;
941 index = pending_index(vif->pending_cons++);
943 pending_idx = vif->pending_ring[index];
945 memcpy(&pending_tx_info[pending_idx].req, txp,
948 /* Poison these fields, corresponding
949 * fields for head tx req will be set
950 * to correct values after the loop.
952 vif->mmap_pages[pending_idx] = (void *)(~0UL);
953 pending_tx_info[pending_idx].head =
954 INVALID_PENDING_RING_IDX;
957 first = &pending_tx_info[pending_idx];
959 head_idx = pending_idx;
969 first->req.offset = 0;
970 first->req.size = dst_offset;
971 first->head = start_idx;
972 vif->mmap_pages[head_idx] = page;
973 frag_set_pending_idx(&frags[shinfo->nr_frags], head_idx);
976 BUG_ON(shinfo->nr_frags > MAX_SKB_FRAGS);
980 /* Unwind, freeing all pages and sending error responses. */
981 while (shinfo->nr_frags-- > start) {
982 xenvif_idx_release(vif,
983 frag_get_pending_idx(&frags[shinfo->nr_frags]),
984 XEN_NETIF_RSP_ERROR);
986 /* The head too, if necessary. */
988 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR);
993 static int xenvif_tx_check_gop(struct xenvif *vif,
995 struct gnttab_copy **gopp)
997 struct gnttab_copy *gop = *gopp;
998 u16 pending_idx = *((u16 *)skb->data);
999 struct skb_shared_info *shinfo = skb_shinfo(skb);
1000 struct pending_tx_info *tx_info;
1001 int nr_frags = shinfo->nr_frags;
1003 u16 peek; /* peek into next tx request */
1005 /* Check status of header. */
1008 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR);
1010 /* Skip first skb fragment if it is on same page as header fragment. */
1011 start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
1013 for (i = start; i < nr_frags; i++) {
1015 pending_ring_idx_t head;
1017 pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
1018 tx_info = &vif->pending_tx_info[pending_idx];
1019 head = tx_info->head;
1021 /* Check error status: if okay then remember grant handle. */
1023 newerr = (++gop)->status;
1026 peek = vif->pending_ring[pending_index(++head)];
1027 } while (!pending_tx_is_head(vif, peek));
1029 if (likely(!newerr)) {
1030 /* Had a previous error? Invalidate this fragment. */
1032 xenvif_idx_release(vif, pending_idx,
1033 XEN_NETIF_RSP_OKAY);
1037 /* Error on this fragment: respond to client with an error. */
1038 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR);
1040 /* Not the first error? Preceding frags already invalidated. */
1044 /* First error: invalidate header and preceding fragments. */
1045 pending_idx = *((u16 *)skb->data);
1046 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY);
1047 for (j = start; j < i; j++) {
1048 pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
1049 xenvif_idx_release(vif, pending_idx,
1050 XEN_NETIF_RSP_OKAY);
1053 /* Remember the error: invalidate all subsequent fragments. */
1061 static void xenvif_fill_frags(struct xenvif *vif, struct sk_buff *skb)
1063 struct skb_shared_info *shinfo = skb_shinfo(skb);
1064 int nr_frags = shinfo->nr_frags;
1067 for (i = 0; i < nr_frags; i++) {
1068 skb_frag_t *frag = shinfo->frags + i;
1069 struct xen_netif_tx_request *txp;
1073 pending_idx = frag_get_pending_idx(frag);
1075 txp = &vif->pending_tx_info[pending_idx].req;
1076 page = virt_to_page(idx_to_kaddr(vif, pending_idx));
1077 __skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
1078 skb->len += txp->size;
1079 skb->data_len += txp->size;
1080 skb->truesize += txp->size;
1082 /* Take an extra reference to offset xenvif_idx_release */
1083 get_page(vif->mmap_pages[pending_idx]);
1084 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY);
1088 static int xenvif_get_extras(struct xenvif *vif,
1089 struct xen_netif_extra_info *extras,
1092 struct xen_netif_extra_info extra;
1093 RING_IDX cons = vif->tx.req_cons;
1096 if (unlikely(work_to_do-- <= 0)) {
1097 netdev_err(vif->dev, "Missing extra info\n");
1098 xenvif_fatal_tx_err(vif);
1102 memcpy(&extra, RING_GET_REQUEST(&vif->tx, cons),
1104 if (unlikely(!extra.type ||
1105 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
1106 vif->tx.req_cons = ++cons;
1107 netdev_err(vif->dev,
1108 "Invalid extra type: %d\n", extra.type);
1109 xenvif_fatal_tx_err(vif);
1113 memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
1114 vif->tx.req_cons = ++cons;
1115 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
1120 static int xenvif_set_skb_gso(struct xenvif *vif,
1121 struct sk_buff *skb,
1122 struct xen_netif_extra_info *gso)
1124 if (!gso->u.gso.size) {
1125 netdev_err(vif->dev, "GSO size must not be zero.\n");
1126 xenvif_fatal_tx_err(vif);
1130 switch (gso->u.gso.type) {
1131 case XEN_NETIF_GSO_TYPE_TCPV4:
1132 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1134 case XEN_NETIF_GSO_TYPE_TCPV6:
1135 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1138 netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
1139 xenvif_fatal_tx_err(vif);
1143 skb_shinfo(skb)->gso_size = gso->u.gso.size;
1145 /* Header must be checked, and gso_segs computed. */
1146 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
1147 skb_shinfo(skb)->gso_segs = 0;
1152 static inline int maybe_pull_tail(struct sk_buff *skb, unsigned int len,
1155 if (skb_headlen(skb) >= len)
1158 /* If we need to pullup then pullup to the max, so we
1159 * won't need to do it again.
1164 if (__pskb_pull_tail(skb, max - skb_headlen(skb)) == NULL)
1167 if (skb_headlen(skb) < len)
1173 /* This value should be large enough to cover a tagged ethernet header plus
1174 * maximally sized IP and TCP or UDP headers.
1176 #define MAX_IP_HDR_LEN 128
1178 static int checksum_setup_ip(struct xenvif *vif, struct sk_buff *skb,
1179 int recalculate_partial_csum)
1187 err = maybe_pull_tail(skb,
1188 sizeof(struct iphdr),
1193 if (ip_hdr(skb)->frag_off & htons(IP_OFFSET | IP_MF))
1196 off = ip_hdrlen(skb);
1203 switch (ip_hdr(skb)->protocol) {
1205 err = maybe_pull_tail(skb,
1206 off + sizeof(struct tcphdr),
1211 if (!skb_partial_csum_set(skb, off,
1212 offsetof(struct tcphdr, check))) {
1217 if (recalculate_partial_csum)
1218 tcp_hdr(skb)->check =
1219 ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
1225 err = maybe_pull_tail(skb,
1226 off + sizeof(struct udphdr),
1231 if (!skb_partial_csum_set(skb, off,
1232 offsetof(struct udphdr, check))) {
1237 if (recalculate_partial_csum)
1238 udp_hdr(skb)->check =
1239 ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
1254 /* This value should be large enough to cover a tagged ethernet header plus
1255 * an IPv6 header, all options, and a maximal TCP or UDP header.
1257 #define MAX_IPV6_HDR_LEN 256
1259 #define OPT_HDR(type, skb, off) \
1260 (type *)(skb_network_header(skb) + (off))
1262 static int checksum_setup_ipv6(struct xenvif *vif, struct sk_buff *skb,
1263 int recalculate_partial_csum)
1275 off = sizeof(struct ipv6hdr);
1277 err = maybe_pull_tail(skb, off, MAX_IPV6_HDR_LEN);
1281 nexthdr = ipv6_hdr(skb)->nexthdr;
1283 len = sizeof(struct ipv6hdr) + ntohs(ipv6_hdr(skb)->payload_len);
1284 while (off <= len && !done) {
1286 case IPPROTO_DSTOPTS:
1287 case IPPROTO_HOPOPTS:
1288 case IPPROTO_ROUTING: {
1289 struct ipv6_opt_hdr *hp;
1291 err = maybe_pull_tail(skb,
1293 sizeof(struct ipv6_opt_hdr),
1298 hp = OPT_HDR(struct ipv6_opt_hdr, skb, off);
1299 nexthdr = hp->nexthdr;
1300 off += ipv6_optlen(hp);
1304 struct ip_auth_hdr *hp;
1306 err = maybe_pull_tail(skb,
1308 sizeof(struct ip_auth_hdr),
1313 hp = OPT_HDR(struct ip_auth_hdr, skb, off);
1314 nexthdr = hp->nexthdr;
1315 off += ipv6_authlen(hp);
1318 case IPPROTO_FRAGMENT: {
1319 struct frag_hdr *hp;
1321 err = maybe_pull_tail(skb,
1323 sizeof(struct frag_hdr),
1328 hp = OPT_HDR(struct frag_hdr, skb, off);
1330 if (hp->frag_off & htons(IP6_OFFSET | IP6_MF))
1333 nexthdr = hp->nexthdr;
1334 off += sizeof(struct frag_hdr);
1345 if (!done || fragment)
1350 err = maybe_pull_tail(skb,
1351 off + sizeof(struct tcphdr),
1356 if (!skb_partial_csum_set(skb, off,
1357 offsetof(struct tcphdr, check))) {
1362 if (recalculate_partial_csum)
1363 tcp_hdr(skb)->check =
1364 ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
1365 &ipv6_hdr(skb)->daddr,
1370 err = maybe_pull_tail(skb,
1371 off + sizeof(struct udphdr),
1376 if (!skb_partial_csum_set(skb, off,
1377 offsetof(struct udphdr, check))) {
1382 if (recalculate_partial_csum)
1383 udp_hdr(skb)->check =
1384 ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
1385 &ipv6_hdr(skb)->daddr,
1399 static int checksum_setup(struct xenvif *vif, struct sk_buff *skb)
1402 int recalculate_partial_csum = 0;
1404 /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
1405 * peers can fail to set NETRXF_csum_blank when sending a GSO
1406 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
1407 * recalculate the partial checksum.
1409 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
1410 vif->rx_gso_checksum_fixup++;
1411 skb->ip_summed = CHECKSUM_PARTIAL;
1412 recalculate_partial_csum = 1;
1415 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
1416 if (skb->ip_summed != CHECKSUM_PARTIAL)
1419 if (skb->protocol == htons(ETH_P_IP))
1420 err = checksum_setup_ip(vif, skb, recalculate_partial_csum);
1421 else if (skb->protocol == htons(ETH_P_IPV6))
1422 err = checksum_setup_ipv6(vif, skb, recalculate_partial_csum);
1427 static bool tx_credit_exceeded(struct xenvif *vif, unsigned size)
1429 u64 now = get_jiffies_64();
1430 u64 next_credit = vif->credit_window_start +
1431 msecs_to_jiffies(vif->credit_usec / 1000);
1433 /* Timer could already be pending in rare cases. */
1434 if (timer_pending(&vif->credit_timeout))
1437 /* Passed the point where we can replenish credit? */
1438 if (time_after_eq64(now, next_credit)) {
1439 vif->credit_window_start = now;
1443 /* Still too big to send right now? Set a callback. */
1444 if (size > vif->remaining_credit) {
1445 vif->credit_timeout.data =
1447 vif->credit_timeout.function =
1449 mod_timer(&vif->credit_timeout,
1451 vif->credit_window_start = next_credit;
1459 static unsigned xenvif_tx_build_gops(struct xenvif *vif, int budget)
1461 struct gnttab_copy *gop = vif->tx_copy_ops, *request_gop;
1462 struct sk_buff *skb;
1465 while ((nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX
1466 < MAX_PENDING_REQS) &&
1467 (skb_queue_len(&vif->tx_queue) < budget)) {
1468 struct xen_netif_tx_request txreq;
1469 struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
1471 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
1475 unsigned int data_len;
1476 pending_ring_idx_t index;
1478 if (vif->tx.sring->req_prod - vif->tx.req_cons >
1479 XEN_NETIF_TX_RING_SIZE) {
1480 netdev_err(vif->dev,
1481 "Impossible number of requests. "
1482 "req_prod %d, req_cons %d, size %ld\n",
1483 vif->tx.sring->req_prod, vif->tx.req_cons,
1484 XEN_NETIF_TX_RING_SIZE);
1485 xenvif_fatal_tx_err(vif);
1489 work_to_do = RING_HAS_UNCONSUMED_REQUESTS(&vif->tx);
1493 idx = vif->tx.req_cons;
1494 rmb(); /* Ensure that we see the request before we copy it. */
1495 memcpy(&txreq, RING_GET_REQUEST(&vif->tx, idx), sizeof(txreq));
1497 /* Credit-based scheduling. */
1498 if (txreq.size > vif->remaining_credit &&
1499 tx_credit_exceeded(vif, txreq.size))
1502 vif->remaining_credit -= txreq.size;
1505 vif->tx.req_cons = ++idx;
1507 memset(extras, 0, sizeof(extras));
1508 if (txreq.flags & XEN_NETTXF_extra_info) {
1509 work_to_do = xenvif_get_extras(vif, extras,
1511 idx = vif->tx.req_cons;
1512 if (unlikely(work_to_do < 0))
1516 ret = xenvif_count_requests(vif, &txreq, txfrags, work_to_do);
1517 if (unlikely(ret < 0))
1522 if (unlikely(txreq.size < ETH_HLEN)) {
1523 netdev_dbg(vif->dev,
1524 "Bad packet size: %d\n", txreq.size);
1525 xenvif_tx_err(vif, &txreq, idx);
1529 /* No crossing a page as the payload mustn't fragment. */
1530 if (unlikely((txreq.offset + txreq.size) > PAGE_SIZE)) {
1531 netdev_err(vif->dev,
1532 "txreq.offset: %x, size: %u, end: %lu\n",
1533 txreq.offset, txreq.size,
1534 (txreq.offset&~PAGE_MASK) + txreq.size);
1535 xenvif_fatal_tx_err(vif);
1539 index = pending_index(vif->pending_cons);
1540 pending_idx = vif->pending_ring[index];
1542 data_len = (txreq.size > PKT_PROT_LEN &&
1543 ret < XEN_NETBK_LEGACY_SLOTS_MAX) ?
1544 PKT_PROT_LEN : txreq.size;
1546 skb = alloc_skb(data_len + NET_SKB_PAD + NET_IP_ALIGN,
1547 GFP_ATOMIC | __GFP_NOWARN);
1548 if (unlikely(skb == NULL)) {
1549 netdev_dbg(vif->dev,
1550 "Can't allocate a skb in start_xmit.\n");
1551 xenvif_tx_err(vif, &txreq, idx);
1555 /* Packets passed to netif_rx() must have some headroom. */
1556 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
1558 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1559 struct xen_netif_extra_info *gso;
1560 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1562 if (xenvif_set_skb_gso(vif, skb, gso)) {
1563 /* Failure in xenvif_set_skb_gso is fatal. */
1569 /* XXX could copy straight to head */
1570 page = xenvif_alloc_page(vif, pending_idx);
1573 xenvif_tx_err(vif, &txreq, idx);
1577 gop->source.u.ref = txreq.gref;
1578 gop->source.domid = vif->domid;
1579 gop->source.offset = txreq.offset;
1581 gop->dest.u.gmfn = virt_to_mfn(page_address(page));
1582 gop->dest.domid = DOMID_SELF;
1583 gop->dest.offset = txreq.offset;
1585 gop->len = txreq.size;
1586 gop->flags = GNTCOPY_source_gref;
1590 memcpy(&vif->pending_tx_info[pending_idx].req,
1591 &txreq, sizeof(txreq));
1592 vif->pending_tx_info[pending_idx].head = index;
1593 *((u16 *)skb->data) = pending_idx;
1595 __skb_put(skb, data_len);
1597 skb_shinfo(skb)->nr_frags = ret;
1598 if (data_len < txreq.size) {
1599 skb_shinfo(skb)->nr_frags++;
1600 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
1603 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
1604 INVALID_PENDING_IDX);
1607 vif->pending_cons++;
1609 request_gop = xenvif_get_requests(vif, skb, txfrags, gop);
1610 if (request_gop == NULL) {
1612 xenvif_tx_err(vif, &txreq, idx);
1617 __skb_queue_tail(&vif->tx_queue, skb);
1619 vif->tx.req_cons = idx;
1621 if ((gop-vif->tx_copy_ops) >= ARRAY_SIZE(vif->tx_copy_ops))
1625 return gop - vif->tx_copy_ops;
1629 static int xenvif_tx_submit(struct xenvif *vif)
1631 struct gnttab_copy *gop = vif->tx_copy_ops;
1632 struct sk_buff *skb;
1635 while ((skb = __skb_dequeue(&vif->tx_queue)) != NULL) {
1636 struct xen_netif_tx_request *txp;
1640 pending_idx = *((u16 *)skb->data);
1641 txp = &vif->pending_tx_info[pending_idx].req;
1643 /* Check the remap error code. */
1644 if (unlikely(xenvif_tx_check_gop(vif, skb, &gop))) {
1645 netdev_dbg(vif->dev, "netback grant failed.\n");
1646 skb_shinfo(skb)->nr_frags = 0;
1651 data_len = skb->len;
1653 (void *)(idx_to_kaddr(vif, pending_idx)|txp->offset),
1655 if (data_len < txp->size) {
1656 /* Append the packet payload as a fragment. */
1657 txp->offset += data_len;
1658 txp->size -= data_len;
1660 /* Schedule a response immediately. */
1661 xenvif_idx_release(vif, pending_idx,
1662 XEN_NETIF_RSP_OKAY);
1665 if (txp->flags & XEN_NETTXF_csum_blank)
1666 skb->ip_summed = CHECKSUM_PARTIAL;
1667 else if (txp->flags & XEN_NETTXF_data_validated)
1668 skb->ip_summed = CHECKSUM_UNNECESSARY;
1670 xenvif_fill_frags(vif, skb);
1672 if (skb_is_nonlinear(skb) && skb_headlen(skb) < PKT_PROT_LEN) {
1673 int target = min_t(int, skb->len, PKT_PROT_LEN);
1674 __pskb_pull_tail(skb, target - skb_headlen(skb));
1677 skb->dev = vif->dev;
1678 skb->protocol = eth_type_trans(skb, skb->dev);
1679 skb_reset_network_header(skb);
1681 if (checksum_setup(vif, skb)) {
1682 netdev_dbg(vif->dev,
1683 "Can't setup checksum in net_tx_action\n");
1688 skb_probe_transport_header(skb, 0);
1690 vif->dev->stats.rx_bytes += skb->len;
1691 vif->dev->stats.rx_packets++;
1695 netif_receive_skb(skb);
1701 /* Called after netfront has transmitted */
1702 int xenvif_tx_action(struct xenvif *vif, int budget)
1707 if (unlikely(!tx_work_todo(vif)))
1710 nr_gops = xenvif_tx_build_gops(vif, budget);
1715 gnttab_batch_copy(vif->tx_copy_ops, nr_gops);
1717 work_done = xenvif_tx_submit(vif);
1722 static void xenvif_idx_release(struct xenvif *vif, u16 pending_idx,
1725 struct pending_tx_info *pending_tx_info;
1726 pending_ring_idx_t head;
1727 u16 peek; /* peek into next tx request */
1729 BUG_ON(vif->mmap_pages[pending_idx] == (void *)(~0UL));
1731 /* Already complete? */
1732 if (vif->mmap_pages[pending_idx] == NULL)
1735 pending_tx_info = &vif->pending_tx_info[pending_idx];
1737 head = pending_tx_info->head;
1739 BUG_ON(!pending_tx_is_head(vif, head));
1740 BUG_ON(vif->pending_ring[pending_index(head)] != pending_idx);
1743 pending_ring_idx_t index;
1744 pending_ring_idx_t idx = pending_index(head);
1745 u16 info_idx = vif->pending_ring[idx];
1747 pending_tx_info = &vif->pending_tx_info[info_idx];
1748 make_tx_response(vif, &pending_tx_info->req, status);
1750 /* Setting any number other than
1751 * INVALID_PENDING_RING_IDX indicates this slot is
1752 * starting a new packet / ending a previous packet.
1754 pending_tx_info->head = 0;
1756 index = pending_index(vif->pending_prod++);
1757 vif->pending_ring[index] = vif->pending_ring[info_idx];
1759 peek = vif->pending_ring[pending_index(++head)];
1761 } while (!pending_tx_is_head(vif, peek));
1763 put_page(vif->mmap_pages[pending_idx]);
1764 vif->mmap_pages[pending_idx] = NULL;
1768 static void make_tx_response(struct xenvif *vif,
1769 struct xen_netif_tx_request *txp,
1772 RING_IDX i = vif->tx.rsp_prod_pvt;
1773 struct xen_netif_tx_response *resp;
1776 resp = RING_GET_RESPONSE(&vif->tx, i);
1780 if (txp->flags & XEN_NETTXF_extra_info)
1781 RING_GET_RESPONSE(&vif->tx, ++i)->status = XEN_NETIF_RSP_NULL;
1783 vif->tx.rsp_prod_pvt = ++i;
1784 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->tx, notify);
1786 notify_remote_via_irq(vif->tx_irq);
1789 static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif,
1796 RING_IDX i = vif->rx.rsp_prod_pvt;
1797 struct xen_netif_rx_response *resp;
1799 resp = RING_GET_RESPONSE(&vif->rx, i);
1800 resp->offset = offset;
1801 resp->flags = flags;
1803 resp->status = (s16)size;
1805 resp->status = (s16)st;
1807 vif->rx.rsp_prod_pvt = ++i;
1812 static inline int rx_work_todo(struct xenvif *vif)
1814 return !skb_queue_empty(&vif->rx_queue);
1817 static inline int tx_work_todo(struct xenvif *vif)
1820 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->tx)) &&
1821 (nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX
1822 < MAX_PENDING_REQS))
1828 void xenvif_unmap_frontend_rings(struct xenvif *vif)
1831 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
1834 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
1838 int xenvif_map_frontend_rings(struct xenvif *vif,
1839 grant_ref_t tx_ring_ref,
1840 grant_ref_t rx_ring_ref)
1843 struct xen_netif_tx_sring *txs;
1844 struct xen_netif_rx_sring *rxs;
1848 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
1849 tx_ring_ref, &addr);
1853 txs = (struct xen_netif_tx_sring *)addr;
1854 BACK_RING_INIT(&vif->tx, txs, PAGE_SIZE);
1856 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
1857 rx_ring_ref, &addr);
1861 rxs = (struct xen_netif_rx_sring *)addr;
1862 BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE);
1864 vif->rx_req_cons_peek = 0;
1869 xenvif_unmap_frontend_rings(vif);
1873 int xenvif_kthread(void *data)
1875 struct xenvif *vif = data;
1877 while (!kthread_should_stop()) {
1878 wait_event_interruptible(vif->wq,
1879 rx_work_todo(vif) ||
1880 kthread_should_stop());
1881 if (kthread_should_stop())
1884 if (rx_work_todo(vif))
1885 xenvif_rx_action(vif);
1893 static int __init netback_init(void)
1900 if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
1901 pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
1902 fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX);
1903 fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX;
1906 rc = xenvif_xenbus_init();
1916 module_init(netback_init);
1918 static void __exit netback_fini(void)
1920 xenvif_xenbus_fini();
1922 module_exit(netback_fini);
1924 MODULE_LICENSE("Dual BSD/GPL");
1925 MODULE_ALIAS("xen-backend:vif");