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>
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);
58 /* When guest ring is filled up, qdisc queues the packets for us, but we have
59 * to timeout them, otherwise other guests' packets can get stucked there
61 unsigned int rx_drain_timeout_msecs = 10000;
62 module_param(rx_drain_timeout_msecs, uint, 0444);
63 unsigned int rx_drain_timeout_jiffies;
66 * This is the maximum slots a skb can have. If a guest sends a skb
67 * which exceeds this limit it is considered malicious.
69 #define FATAL_SKB_SLOTS_DEFAULT 20
70 static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT;
71 module_param(fatal_skb_slots, uint, 0444);
73 static void xenvif_idx_release(struct xenvif *vif, u16 pending_idx,
76 static void make_tx_response(struct xenvif *vif,
77 struct xen_netif_tx_request *txp,
80 static inline int tx_work_todo(struct xenvif *vif);
81 static inline int rx_work_todo(struct xenvif *vif);
83 static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif,
90 static inline unsigned long idx_to_pfn(struct xenvif *vif,
93 return page_to_pfn(vif->mmap_pages[idx]);
96 static inline unsigned long idx_to_kaddr(struct xenvif *vif,
99 return (unsigned long)pfn_to_kaddr(idx_to_pfn(vif, idx));
102 /* Find the containing VIF's structure from a pointer in pending_tx_info array
104 static inline struct xenvif* ubuf_to_vif(struct ubuf_info *ubuf)
106 u16 pending_idx = ubuf->desc;
107 struct pending_tx_info *temp =
108 container_of(ubuf, struct pending_tx_info, callback_struct);
109 return container_of(temp - pending_idx,
114 /* This is a miniumum size for the linear area to avoid lots of
115 * calls to __pskb_pull_tail() as we set up checksum offsets. The
116 * value 128 was chosen as it covers all IPv4 and most likely
119 #define PKT_PROT_LEN 128
121 static u16 frag_get_pending_idx(skb_frag_t *frag)
123 return (u16)frag->page_offset;
126 static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx)
128 frag->page_offset = pending_idx;
131 static inline pending_ring_idx_t pending_index(unsigned i)
133 return i & (MAX_PENDING_REQS-1);
136 bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed)
141 prod = vif->rx.sring->req_prod;
142 cons = vif->rx.req_cons;
144 if (prod - cons >= needed)
147 vif->rx.sring->req_event = prod + 1;
149 /* Make sure event is visible before we check prod
153 } while (vif->rx.sring->req_prod != prod);
159 * Returns true if we should start a new receive buffer instead of
160 * adding 'size' bytes to a buffer which currently contains 'offset'
163 static bool start_new_rx_buffer(int offset, unsigned long size, int head)
165 /* simple case: we have completely filled the current buffer. */
166 if (offset == MAX_BUFFER_OFFSET)
170 * complex case: start a fresh buffer if the current frag
171 * would overflow the current buffer but only if:
172 * (i) this frag would fit completely in the next buffer
173 * and (ii) there is already some data in the current buffer
174 * and (iii) this is not the head buffer.
177 * - (i) stops us splitting a frag into two copies
178 * unless the frag is too large for a single buffer.
179 * - (ii) stops us from leaving a buffer pointlessly empty.
180 * - (iii) stops us leaving the first buffer
181 * empty. Strictly speaking this is already covered
182 * by (ii) but is explicitly checked because
183 * netfront relies on the first buffer being
184 * non-empty and can crash otherwise.
186 * This means we will effectively linearise small
187 * frags but do not needlessly split large buffers
188 * into multiple copies tend to give large frags their
189 * own buffers as before.
191 if ((offset + size > MAX_BUFFER_OFFSET) &&
192 (size <= MAX_BUFFER_OFFSET) && offset && !head)
198 struct netrx_pending_operations {
199 unsigned copy_prod, copy_cons;
200 unsigned meta_prod, meta_cons;
201 struct gnttab_copy *copy;
202 struct xenvif_rx_meta *meta;
204 grant_ref_t copy_gref;
207 static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif *vif,
208 struct netrx_pending_operations *npo)
210 struct xenvif_rx_meta *meta;
211 struct xen_netif_rx_request *req;
213 req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
215 meta = npo->meta + npo->meta_prod++;
216 meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
222 npo->copy_gref = req->gref;
228 * Set up the grant operations for this fragment. If it's a flipping
229 * interface, we also set up the unmap request from here.
231 static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb,
232 struct netrx_pending_operations *npo,
233 struct page *page, unsigned long size,
234 unsigned long offset, int *head,
235 struct xenvif *foreign_vif,
236 grant_ref_t foreign_gref)
238 struct gnttab_copy *copy_gop;
239 struct xenvif_rx_meta *meta;
241 int gso_type = XEN_NETIF_GSO_TYPE_NONE;
243 /* Data must not cross a page boundary. */
244 BUG_ON(size + offset > PAGE_SIZE<<compound_order(page));
246 meta = npo->meta + npo->meta_prod - 1;
248 /* Skip unused frames from start of page */
249 page += offset >> PAGE_SHIFT;
250 offset &= ~PAGE_MASK;
253 BUG_ON(offset >= PAGE_SIZE);
254 BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET);
256 bytes = PAGE_SIZE - offset;
261 if (start_new_rx_buffer(npo->copy_off, bytes, *head)) {
263 * Netfront requires there to be some data in the head
268 meta = get_next_rx_buffer(vif, npo);
271 if (npo->copy_off + bytes > MAX_BUFFER_OFFSET)
272 bytes = MAX_BUFFER_OFFSET - npo->copy_off;
274 copy_gop = npo->copy + npo->copy_prod++;
275 copy_gop->flags = GNTCOPY_dest_gref;
276 copy_gop->len = bytes;
279 copy_gop->source.domid = foreign_vif->domid;
280 copy_gop->source.u.ref = foreign_gref;
281 copy_gop->flags |= GNTCOPY_source_gref;
283 copy_gop->source.domid = DOMID_SELF;
284 copy_gop->source.u.gmfn =
285 virt_to_mfn(page_address(page));
287 copy_gop->source.offset = offset;
289 copy_gop->dest.domid = vif->domid;
290 copy_gop->dest.offset = npo->copy_off;
291 copy_gop->dest.u.ref = npo->copy_gref;
293 npo->copy_off += bytes;
300 if (offset == PAGE_SIZE && size) {
301 BUG_ON(!PageCompound(page));
306 /* Leave a gap for the GSO descriptor. */
307 if (skb_is_gso(skb)) {
308 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
309 gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
310 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
311 gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
314 if (*head && ((1 << gso_type) & vif->gso_mask))
317 *head = 0; /* There must be something in this buffer now. */
323 * Prepare an SKB to be transmitted to the frontend.
325 * This function is responsible for allocating grant operations, meta
328 * It returns the number of meta structures consumed. The number of
329 * ring slots used is always equal to the number of meta slots used
330 * plus the number of GSO descriptors used. Currently, we use either
331 * zero GSO descriptors (for non-GSO packets) or one descriptor (for
332 * frontend-side LRO).
334 static int xenvif_gop_skb(struct sk_buff *skb,
335 struct netrx_pending_operations *npo)
337 struct xenvif *vif = netdev_priv(skb->dev);
338 int nr_frags = skb_shinfo(skb)->nr_frags;
340 struct xen_netif_rx_request *req;
341 struct xenvif_rx_meta *meta;
346 struct ubuf_info *ubuf = skb_shinfo(skb)->destructor_arg;
347 grant_ref_t foreign_grefs[MAX_SKB_FRAGS];
348 struct xenvif *foreign_vif = NULL;
350 old_meta_prod = npo->meta_prod;
352 gso_type = XEN_NETIF_GSO_TYPE_NONE;
353 if (skb_is_gso(skb)) {
354 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
355 gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
356 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
357 gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
360 /* Set up a GSO prefix descriptor, if necessary */
361 if ((1 << gso_type) & vif->gso_prefix_mask) {
362 req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
363 meta = npo->meta + npo->meta_prod++;
364 meta->gso_type = gso_type;
365 meta->gso_size = skb_shinfo(skb)->gso_size;
370 req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
371 meta = npo->meta + npo->meta_prod++;
373 if ((1 << gso_type) & vif->gso_mask) {
374 meta->gso_type = gso_type;
375 meta->gso_size = skb_shinfo(skb)->gso_size;
377 meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
384 npo->copy_gref = req->gref;
386 if ((skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) &&
387 (ubuf->callback == &xenvif_zerocopy_callback)) {
389 foreign_vif = ubuf_to_vif(ubuf);
392 u16 pending_idx = ubuf->desc;
394 foreign_vif->pending_tx_info[pending_idx].req.gref;
395 ubuf = (struct ubuf_info *) ubuf->ctx;
400 while (data < skb_tail_pointer(skb)) {
401 unsigned int offset = offset_in_page(data);
402 unsigned int len = PAGE_SIZE - offset;
404 if (data + len > skb_tail_pointer(skb))
405 len = skb_tail_pointer(skb) - data;
407 xenvif_gop_frag_copy(vif, skb, npo,
408 virt_to_page(data), len, offset, &head,
414 for (i = 0; i < nr_frags; i++) {
415 xenvif_gop_frag_copy(vif, skb, npo,
416 skb_frag_page(&skb_shinfo(skb)->frags[i]),
417 skb_frag_size(&skb_shinfo(skb)->frags[i]),
418 skb_shinfo(skb)->frags[i].page_offset,
424 return npo->meta_prod - old_meta_prod;
428 * This is a twin to xenvif_gop_skb. Assume that xenvif_gop_skb was
429 * used to set up the operations on the top of
430 * netrx_pending_operations, which have since been done. Check that
431 * they didn't give any errors and advance over them.
433 static int xenvif_check_gop(struct xenvif *vif, int nr_meta_slots,
434 struct netrx_pending_operations *npo)
436 struct gnttab_copy *copy_op;
437 int status = XEN_NETIF_RSP_OKAY;
440 for (i = 0; i < nr_meta_slots; i++) {
441 copy_op = npo->copy + npo->copy_cons++;
442 if (copy_op->status != GNTST_okay) {
444 "Bad status %d from copy to DOM%d.\n",
445 copy_op->status, vif->domid);
446 status = XEN_NETIF_RSP_ERROR;
453 static void xenvif_add_frag_responses(struct xenvif *vif, int status,
454 struct xenvif_rx_meta *meta,
458 unsigned long offset;
460 /* No fragments used */
461 if (nr_meta_slots <= 1)
466 for (i = 0; i < nr_meta_slots; i++) {
468 if (i == nr_meta_slots - 1)
471 flags = XEN_NETRXF_more_data;
474 make_rx_response(vif, meta[i].id, status, offset,
475 meta[i].size, flags);
479 struct xenvif_rx_cb {
483 #define XENVIF_RX_CB(skb) ((struct xenvif_rx_cb *)(skb)->cb)
485 void xenvif_kick_thread(struct xenvif *vif)
490 static void xenvif_rx_action(struct xenvif *vif)
494 struct xen_netif_rx_response *resp;
495 struct sk_buff_head rxq;
499 unsigned long offset;
500 bool need_to_notify = false;
502 struct netrx_pending_operations npo = {
503 .copy = vif->grant_copy_op,
507 skb_queue_head_init(&rxq);
509 while ((skb = skb_dequeue(&vif->rx_queue)) != NULL) {
510 RING_IDX max_slots_needed;
513 /* We need a cheap worse case estimate for the number of
517 max_slots_needed = DIV_ROUND_UP(offset_in_page(skb->data) +
520 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
522 size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
523 max_slots_needed += DIV_ROUND_UP(size, PAGE_SIZE);
525 if (skb_is_gso(skb) &&
526 (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4 ||
527 skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6))
530 /* If the skb may not fit then bail out now */
531 if (!xenvif_rx_ring_slots_available(vif, max_slots_needed)) {
532 skb_queue_head(&vif->rx_queue, skb);
533 need_to_notify = true;
534 vif->rx_last_skb_slots = max_slots_needed;
537 vif->rx_last_skb_slots = 0;
539 XENVIF_RX_CB(skb)->meta_slots_used = xenvif_gop_skb(skb, &npo);
540 BUG_ON(XENVIF_RX_CB(skb)->meta_slots_used > max_slots_needed);
542 __skb_queue_tail(&rxq, skb);
545 BUG_ON(npo.meta_prod > ARRAY_SIZE(vif->meta));
550 BUG_ON(npo.copy_prod > MAX_GRANT_COPY_OPS);
551 gnttab_batch_copy(vif->grant_copy_op, npo.copy_prod);
553 while ((skb = __skb_dequeue(&rxq)) != NULL) {
555 if ((1 << vif->meta[npo.meta_cons].gso_type) &
556 vif->gso_prefix_mask) {
557 resp = RING_GET_RESPONSE(&vif->rx,
558 vif->rx.rsp_prod_pvt++);
560 resp->flags = XEN_NETRXF_gso_prefix | XEN_NETRXF_more_data;
562 resp->offset = vif->meta[npo.meta_cons].gso_size;
563 resp->id = vif->meta[npo.meta_cons].id;
564 resp->status = XENVIF_RX_CB(skb)->meta_slots_used;
567 XENVIF_RX_CB(skb)->meta_slots_used--;
571 vif->dev->stats.tx_bytes += skb->len;
572 vif->dev->stats.tx_packets++;
574 status = xenvif_check_gop(vif,
575 XENVIF_RX_CB(skb)->meta_slots_used,
578 if (XENVIF_RX_CB(skb)->meta_slots_used == 1)
581 flags = XEN_NETRXF_more_data;
583 if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */
584 flags |= XEN_NETRXF_csum_blank | XEN_NETRXF_data_validated;
585 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
586 /* remote but checksummed. */
587 flags |= XEN_NETRXF_data_validated;
590 resp = make_rx_response(vif, vif->meta[npo.meta_cons].id,
592 vif->meta[npo.meta_cons].size,
595 if ((1 << vif->meta[npo.meta_cons].gso_type) &
597 struct xen_netif_extra_info *gso =
598 (struct xen_netif_extra_info *)
599 RING_GET_RESPONSE(&vif->rx,
600 vif->rx.rsp_prod_pvt++);
602 resp->flags |= XEN_NETRXF_extra_info;
604 gso->u.gso.type = vif->meta[npo.meta_cons].gso_type;
605 gso->u.gso.size = vif->meta[npo.meta_cons].gso_size;
607 gso->u.gso.features = 0;
609 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
613 xenvif_add_frag_responses(vif, status,
614 vif->meta + npo.meta_cons + 1,
615 XENVIF_RX_CB(skb)->meta_slots_used);
617 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->rx, ret);
619 need_to_notify |= !!ret;
621 npo.meta_cons += XENVIF_RX_CB(skb)->meta_slots_used;
627 notify_remote_via_irq(vif->rx_irq);
630 void xenvif_check_rx_xenvif(struct xenvif *vif)
634 RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do);
637 napi_schedule(&vif->napi);
640 static void tx_add_credit(struct xenvif *vif)
642 unsigned long max_burst, max_credit;
645 * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
646 * Otherwise the interface can seize up due to insufficient credit.
648 max_burst = RING_GET_REQUEST(&vif->tx, vif->tx.req_cons)->size;
649 max_burst = min(max_burst, 131072UL);
650 max_burst = max(max_burst, vif->credit_bytes);
652 /* Take care that adding a new chunk of credit doesn't wrap to zero. */
653 max_credit = vif->remaining_credit + vif->credit_bytes;
654 if (max_credit < vif->remaining_credit)
655 max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
657 vif->remaining_credit = min(max_credit, max_burst);
660 static void tx_credit_callback(unsigned long data)
662 struct xenvif *vif = (struct xenvif *)data;
664 xenvif_check_rx_xenvif(vif);
667 static void xenvif_tx_err(struct xenvif *vif,
668 struct xen_netif_tx_request *txp, RING_IDX end)
670 RING_IDX cons = vif->tx.req_cons;
674 spin_lock_irqsave(&vif->response_lock, flags);
675 make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR);
676 spin_unlock_irqrestore(&vif->response_lock, flags);
679 txp = RING_GET_REQUEST(&vif->tx, cons++);
681 vif->tx.req_cons = cons;
684 static void xenvif_fatal_tx_err(struct xenvif *vif)
686 netdev_err(vif->dev, "fatal error; disabling device\n");
687 xenvif_carrier_off(vif);
690 static int xenvif_count_requests(struct xenvif *vif,
691 struct xen_netif_tx_request *first,
692 struct xen_netif_tx_request *txp,
695 RING_IDX cons = vif->tx.req_cons;
700 if (!(first->flags & XEN_NETTXF_more_data))
704 struct xen_netif_tx_request dropped_tx = { 0 };
706 if (slots >= work_to_do) {
708 "Asked for %d slots but exceeds this limit\n",
710 xenvif_fatal_tx_err(vif);
714 /* This guest is really using too many slots and
715 * considered malicious.
717 if (unlikely(slots >= fatal_skb_slots)) {
719 "Malicious frontend using %d slots, threshold %u\n",
720 slots, fatal_skb_slots);
721 xenvif_fatal_tx_err(vif);
725 /* Xen network protocol had implicit dependency on
726 * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to
727 * the historical MAX_SKB_FRAGS value 18 to honor the
728 * same behavior as before. Any packet using more than
729 * 18 slots but less than fatal_skb_slots slots is
732 if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) {
735 "Too many slots (%d) exceeding limit (%d), dropping packet\n",
736 slots, XEN_NETBK_LEGACY_SLOTS_MAX);
743 memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + slots),
746 /* If the guest submitted a frame >= 64 KiB then
747 * first->size overflowed and following slots will
748 * appear to be larger than the frame.
750 * This cannot be fatal error as there are buggy
751 * frontends that do this.
753 * Consume all slots and drop the packet.
755 if (!drop_err && txp->size > first->size) {
758 "Invalid tx request, slot size %u > remaining size %u\n",
759 txp->size, first->size);
763 first->size -= txp->size;
766 if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) {
767 netdev_err(vif->dev, "Cross page boundary, txp->offset: %x, size: %u\n",
768 txp->offset, txp->size);
769 xenvif_fatal_tx_err(vif);
773 more_data = txp->flags & XEN_NETTXF_more_data;
781 xenvif_tx_err(vif, first, cons + slots);
789 struct xenvif_tx_cb {
793 #define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb)
795 static inline void xenvif_tx_create_gop(struct xenvif *vif,
797 struct xen_netif_tx_request *txp,
798 struct gnttab_map_grant_ref *gop)
800 vif->pages_to_map[gop-vif->tx_map_ops] = vif->mmap_pages[pending_idx];
801 gnttab_set_map_op(gop, idx_to_kaddr(vif, pending_idx),
802 GNTMAP_host_map | GNTMAP_readonly,
803 txp->gref, vif->domid);
805 memcpy(&vif->pending_tx_info[pending_idx].req, txp,
809 static inline struct sk_buff *xenvif_alloc_skb(unsigned int size)
811 struct sk_buff *skb =
812 alloc_skb(size + NET_SKB_PAD + NET_IP_ALIGN,
813 GFP_ATOMIC | __GFP_NOWARN);
814 if (unlikely(skb == NULL))
817 /* Packets passed to netif_rx() must have some headroom. */
818 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
820 /* Initialize it here to avoid later surprises */
821 skb_shinfo(skb)->destructor_arg = NULL;
826 static struct gnttab_map_grant_ref *xenvif_get_requests(struct xenvif *vif,
828 struct xen_netif_tx_request *txp,
829 struct gnttab_map_grant_ref *gop)
831 struct skb_shared_info *shinfo = skb_shinfo(skb);
832 skb_frag_t *frags = shinfo->frags;
833 u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
835 pending_ring_idx_t index;
836 unsigned int nr_slots, frag_overflow = 0;
838 /* At this point shinfo->nr_frags is in fact the number of
839 * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
841 if (shinfo->nr_frags > MAX_SKB_FRAGS) {
842 frag_overflow = shinfo->nr_frags - MAX_SKB_FRAGS;
843 BUG_ON(frag_overflow > MAX_SKB_FRAGS);
844 shinfo->nr_frags = MAX_SKB_FRAGS;
846 nr_slots = shinfo->nr_frags;
848 /* Skip first skb fragment if it is on same page as header fragment. */
849 start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
851 for (shinfo->nr_frags = start; shinfo->nr_frags < nr_slots;
852 shinfo->nr_frags++, txp++, gop++) {
853 index = pending_index(vif->pending_cons++);
854 pending_idx = vif->pending_ring[index];
855 xenvif_tx_create_gop(vif, pending_idx, txp, gop);
856 frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx);
860 struct sk_buff *nskb = xenvif_alloc_skb(0);
861 if (unlikely(nskb == NULL)) {
864 "Can't allocate the frag_list skb.\n");
868 shinfo = skb_shinfo(nskb);
869 frags = shinfo->frags;
871 for (shinfo->nr_frags = 0; shinfo->nr_frags < frag_overflow;
872 shinfo->nr_frags++, txp++, gop++) {
873 index = pending_index(vif->pending_cons++);
874 pending_idx = vif->pending_ring[index];
875 xenvif_tx_create_gop(vif, pending_idx, txp, gop);
876 frag_set_pending_idx(&frags[shinfo->nr_frags],
880 skb_shinfo(skb)->frag_list = nskb;
886 static inline void xenvif_grant_handle_set(struct xenvif *vif,
888 grant_handle_t handle)
890 if (unlikely(vif->grant_tx_handle[pending_idx] !=
891 NETBACK_INVALID_HANDLE)) {
893 "Trying to overwrite active handle! pending_idx: %x\n",
897 vif->grant_tx_handle[pending_idx] = handle;
900 static inline void xenvif_grant_handle_reset(struct xenvif *vif,
903 if (unlikely(vif->grant_tx_handle[pending_idx] ==
904 NETBACK_INVALID_HANDLE)) {
906 "Trying to unmap invalid handle! pending_idx: %x\n",
910 vif->grant_tx_handle[pending_idx] = NETBACK_INVALID_HANDLE;
913 static int xenvif_tx_check_gop(struct xenvif *vif,
915 struct gnttab_map_grant_ref **gopp)
917 struct gnttab_map_grant_ref *gop = *gopp;
918 u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
919 struct skb_shared_info *shinfo = skb_shinfo(skb);
920 struct pending_tx_info *tx_info;
921 int nr_frags = shinfo->nr_frags;
923 struct sk_buff *first_skb = NULL;
925 /* Check status of header. */
928 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR);
930 xenvif_grant_handle_set(vif, pending_idx , gop->handle);
932 /* Skip first skb fragment if it is on same page as header fragment. */
933 start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
936 for (i = start; i < nr_frags; i++) {
939 pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
940 tx_info = &vif->pending_tx_info[pending_idx];
942 /* Check error status: if okay then remember grant handle. */
943 newerr = (++gop)->status;
945 if (likely(!newerr)) {
946 xenvif_grant_handle_set(vif, pending_idx , gop->handle);
947 /* Had a previous error? Invalidate this fragment. */
949 xenvif_idx_unmap(vif, pending_idx);
953 /* Error on this fragment: respond to client with an error. */
954 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR);
956 /* Not the first error? Preceding frags already invalidated. */
959 /* First error: invalidate header and preceding fragments. */
961 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
963 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
964 xenvif_idx_unmap(vif, pending_idx);
965 for (j = start; j < i; j++) {
966 pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
967 xenvif_idx_unmap(vif, pending_idx);
970 /* Remember the error: invalidate all subsequent fragments. */
974 if (skb_has_frag_list(skb)) {
976 skb = shinfo->frag_list;
977 shinfo = skb_shinfo(skb);
978 nr_frags = shinfo->nr_frags;
984 /* There was a mapping error in the frag_list skb. We have to unmap
985 * the first skb's frags
987 if (first_skb && err) {
989 shinfo = skb_shinfo(first_skb);
990 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
991 start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
992 for (j = start; j < shinfo->nr_frags; j++) {
993 pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
994 xenvif_idx_unmap(vif, pending_idx);
1002 static void xenvif_fill_frags(struct xenvif *vif, struct sk_buff *skb)
1004 struct skb_shared_info *shinfo = skb_shinfo(skb);
1005 int nr_frags = shinfo->nr_frags;
1007 u16 prev_pending_idx = INVALID_PENDING_IDX;
1009 if (skb_shinfo(skb)->destructor_arg)
1010 prev_pending_idx = XENVIF_TX_CB(skb)->pending_idx;
1012 for (i = 0; i < nr_frags; i++) {
1013 skb_frag_t *frag = shinfo->frags + i;
1014 struct xen_netif_tx_request *txp;
1018 pending_idx = frag_get_pending_idx(frag);
1020 /* If this is not the first frag, chain it to the previous*/
1021 if (unlikely(prev_pending_idx == INVALID_PENDING_IDX))
1022 skb_shinfo(skb)->destructor_arg =
1023 &vif->pending_tx_info[pending_idx].callback_struct;
1024 else if (likely(pending_idx != prev_pending_idx))
1025 vif->pending_tx_info[prev_pending_idx].callback_struct.ctx =
1026 &(vif->pending_tx_info[pending_idx].callback_struct);
1028 vif->pending_tx_info[pending_idx].callback_struct.ctx = NULL;
1029 prev_pending_idx = pending_idx;
1031 txp = &vif->pending_tx_info[pending_idx].req;
1032 page = virt_to_page(idx_to_kaddr(vif, pending_idx));
1033 __skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
1034 skb->len += txp->size;
1035 skb->data_len += txp->size;
1036 skb->truesize += txp->size;
1038 /* Take an extra reference to offset network stack's put_page */
1039 get_page(vif->mmap_pages[pending_idx]);
1041 /* FIXME: __skb_fill_page_desc set this to true because page->pfmemalloc
1042 * overlaps with "index", and "mapping" is not set. I think mapping
1043 * should be set. If delivered to local stack, it would drop this
1044 * skb in sk_filter unless the socket has the right to use it.
1046 skb->pfmemalloc = false;
1049 static int xenvif_get_extras(struct xenvif *vif,
1050 struct xen_netif_extra_info *extras,
1053 struct xen_netif_extra_info extra;
1054 RING_IDX cons = vif->tx.req_cons;
1057 if (unlikely(work_to_do-- <= 0)) {
1058 netdev_err(vif->dev, "Missing extra info\n");
1059 xenvif_fatal_tx_err(vif);
1063 memcpy(&extra, RING_GET_REQUEST(&vif->tx, cons),
1065 if (unlikely(!extra.type ||
1066 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
1067 vif->tx.req_cons = ++cons;
1068 netdev_err(vif->dev,
1069 "Invalid extra type: %d\n", extra.type);
1070 xenvif_fatal_tx_err(vif);
1074 memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
1075 vif->tx.req_cons = ++cons;
1076 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
1081 static int xenvif_set_skb_gso(struct xenvif *vif,
1082 struct sk_buff *skb,
1083 struct xen_netif_extra_info *gso)
1085 if (!gso->u.gso.size) {
1086 netdev_err(vif->dev, "GSO size must not be zero.\n");
1087 xenvif_fatal_tx_err(vif);
1091 switch (gso->u.gso.type) {
1092 case XEN_NETIF_GSO_TYPE_TCPV4:
1093 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1095 case XEN_NETIF_GSO_TYPE_TCPV6:
1096 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1099 netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
1100 xenvif_fatal_tx_err(vif);
1104 skb_shinfo(skb)->gso_size = gso->u.gso.size;
1105 /* gso_segs will be calculated later */
1110 static int checksum_setup(struct xenvif *vif, struct sk_buff *skb)
1112 bool recalculate_partial_csum = false;
1114 /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
1115 * peers can fail to set NETRXF_csum_blank when sending a GSO
1116 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
1117 * recalculate the partial checksum.
1119 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
1120 vif->rx_gso_checksum_fixup++;
1121 skb->ip_summed = CHECKSUM_PARTIAL;
1122 recalculate_partial_csum = true;
1125 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
1126 if (skb->ip_summed != CHECKSUM_PARTIAL)
1129 return skb_checksum_setup(skb, recalculate_partial_csum);
1132 static bool tx_credit_exceeded(struct xenvif *vif, unsigned size)
1134 u64 now = get_jiffies_64();
1135 u64 next_credit = vif->credit_window_start +
1136 msecs_to_jiffies(vif->credit_usec / 1000);
1138 /* Timer could already be pending in rare cases. */
1139 if (timer_pending(&vif->credit_timeout))
1142 /* Passed the point where we can replenish credit? */
1143 if (time_after_eq64(now, next_credit)) {
1144 vif->credit_window_start = now;
1148 /* Still too big to send right now? Set a callback. */
1149 if (size > vif->remaining_credit) {
1150 vif->credit_timeout.data =
1152 vif->credit_timeout.function =
1154 mod_timer(&vif->credit_timeout,
1156 vif->credit_window_start = next_credit;
1164 static unsigned xenvif_tx_build_gops(struct xenvif *vif, int budget)
1166 struct gnttab_map_grant_ref *gop = vif->tx_map_ops, *request_gop;
1167 struct sk_buff *skb;
1170 while (xenvif_tx_pending_slots_available(vif) &&
1171 (skb_queue_len(&vif->tx_queue) < budget)) {
1172 struct xen_netif_tx_request txreq;
1173 struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
1174 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
1178 unsigned int data_len;
1179 pending_ring_idx_t index;
1181 if (vif->tx.sring->req_prod - vif->tx.req_cons >
1182 XEN_NETIF_TX_RING_SIZE) {
1183 netdev_err(vif->dev,
1184 "Impossible number of requests. "
1185 "req_prod %d, req_cons %d, size %ld\n",
1186 vif->tx.sring->req_prod, vif->tx.req_cons,
1187 XEN_NETIF_TX_RING_SIZE);
1188 xenvif_fatal_tx_err(vif);
1192 work_to_do = RING_HAS_UNCONSUMED_REQUESTS(&vif->tx);
1196 idx = vif->tx.req_cons;
1197 rmb(); /* Ensure that we see the request before we copy it. */
1198 memcpy(&txreq, RING_GET_REQUEST(&vif->tx, idx), sizeof(txreq));
1200 /* Credit-based scheduling. */
1201 if (txreq.size > vif->remaining_credit &&
1202 tx_credit_exceeded(vif, txreq.size))
1205 vif->remaining_credit -= txreq.size;
1208 vif->tx.req_cons = ++idx;
1210 memset(extras, 0, sizeof(extras));
1211 if (txreq.flags & XEN_NETTXF_extra_info) {
1212 work_to_do = xenvif_get_extras(vif, extras,
1214 idx = vif->tx.req_cons;
1215 if (unlikely(work_to_do < 0))
1219 ret = xenvif_count_requests(vif, &txreq, txfrags, work_to_do);
1220 if (unlikely(ret < 0))
1225 if (unlikely(txreq.size < ETH_HLEN)) {
1226 netdev_dbg(vif->dev,
1227 "Bad packet size: %d\n", txreq.size);
1228 xenvif_tx_err(vif, &txreq, idx);
1232 /* No crossing a page as the payload mustn't fragment. */
1233 if (unlikely((txreq.offset + txreq.size) > PAGE_SIZE)) {
1234 netdev_err(vif->dev,
1235 "txreq.offset: %x, size: %u, end: %lu\n",
1236 txreq.offset, txreq.size,
1237 (txreq.offset&~PAGE_MASK) + txreq.size);
1238 xenvif_fatal_tx_err(vif);
1242 index = pending_index(vif->pending_cons);
1243 pending_idx = vif->pending_ring[index];
1245 data_len = (txreq.size > PKT_PROT_LEN &&
1246 ret < XEN_NETBK_LEGACY_SLOTS_MAX) ?
1247 PKT_PROT_LEN : txreq.size;
1249 skb = xenvif_alloc_skb(data_len);
1250 if (unlikely(skb == NULL)) {
1251 netdev_dbg(vif->dev,
1252 "Can't allocate a skb in start_xmit.\n");
1253 xenvif_tx_err(vif, &txreq, idx);
1257 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1258 struct xen_netif_extra_info *gso;
1259 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1261 if (xenvif_set_skb_gso(vif, skb, gso)) {
1262 /* Failure in xenvif_set_skb_gso is fatal. */
1268 xenvif_tx_create_gop(vif, pending_idx, &txreq, gop);
1272 XENVIF_TX_CB(skb)->pending_idx = pending_idx;
1274 __skb_put(skb, data_len);
1276 skb_shinfo(skb)->nr_frags = ret;
1277 if (data_len < txreq.size) {
1278 skb_shinfo(skb)->nr_frags++;
1279 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
1282 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
1283 INVALID_PENDING_IDX);
1286 vif->pending_cons++;
1288 request_gop = xenvif_get_requests(vif, skb, txfrags, gop);
1289 if (request_gop == NULL) {
1291 xenvif_tx_err(vif, &txreq, idx);
1296 __skb_queue_tail(&vif->tx_queue, skb);
1298 vif->tx.req_cons = idx;
1300 if ((gop-vif->tx_map_ops) >= ARRAY_SIZE(vif->tx_map_ops))
1304 return gop - vif->tx_map_ops;
1307 /* Consolidate skb with a frag_list into a brand new one with local pages on
1308 * frags. Returns 0 or -ENOMEM if can't allocate new pages.
1310 static int xenvif_handle_frag_list(struct xenvif *vif, struct sk_buff *skb)
1312 unsigned int offset = skb_headlen(skb);
1313 skb_frag_t frags[MAX_SKB_FRAGS];
1315 struct ubuf_info *uarg;
1316 struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
1318 vif->tx_zerocopy_sent += 2;
1319 vif->tx_frag_overflow++;
1321 xenvif_fill_frags(vif, nskb);
1322 /* Subtract frags size, we will correct it later */
1323 skb->truesize -= skb->data_len;
1324 skb->len += nskb->len;
1325 skb->data_len += nskb->len;
1327 /* create a brand new frags array and coalesce there */
1328 for (i = 0; offset < skb->len; i++) {
1332 BUG_ON(i >= MAX_SKB_FRAGS);
1333 page = alloc_page(GFP_ATOMIC|__GFP_COLD);
1336 skb->truesize += skb->data_len;
1337 for (j = 0; j < i; j++)
1338 put_page(frags[j].page.p);
1342 if (offset + PAGE_SIZE < skb->len)
1345 len = skb->len - offset;
1346 if (skb_copy_bits(skb, offset, page_address(page), len))
1350 frags[i].page.p = page;
1351 frags[i].page_offset = 0;
1352 skb_frag_size_set(&frags[i], len);
1354 /* swap out with old one */
1355 memcpy(skb_shinfo(skb)->frags,
1357 i * sizeof(skb_frag_t));
1358 skb_shinfo(skb)->nr_frags = i;
1359 skb->truesize += i * PAGE_SIZE;
1361 /* remove traces of mapped pages and frag_list */
1362 skb_frag_list_init(skb);
1363 uarg = skb_shinfo(skb)->destructor_arg;
1364 uarg->callback(uarg, true);
1365 skb_shinfo(skb)->destructor_arg = NULL;
1367 skb_shinfo(nskb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1373 static int xenvif_tx_submit(struct xenvif *vif)
1375 struct gnttab_map_grant_ref *gop = vif->tx_map_ops;
1376 struct sk_buff *skb;
1379 while ((skb = __skb_dequeue(&vif->tx_queue)) != NULL) {
1380 struct xen_netif_tx_request *txp;
1384 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
1385 txp = &vif->pending_tx_info[pending_idx].req;
1387 /* Check the remap error code. */
1388 if (unlikely(xenvif_tx_check_gop(vif, skb, &gop))) {
1389 netdev_dbg(vif->dev, "netback grant failed.\n");
1390 skb_shinfo(skb)->nr_frags = 0;
1395 data_len = skb->len;
1397 (void *)(idx_to_kaddr(vif, pending_idx)|txp->offset),
1399 vif->pending_tx_info[pending_idx].callback_struct.ctx = NULL;
1400 if (data_len < txp->size) {
1401 /* Append the packet payload as a fragment. */
1402 txp->offset += data_len;
1403 txp->size -= data_len;
1404 skb_shinfo(skb)->destructor_arg =
1405 &vif->pending_tx_info[pending_idx].callback_struct;
1407 /* Schedule a response immediately. */
1408 xenvif_idx_unmap(vif, pending_idx);
1411 if (txp->flags & XEN_NETTXF_csum_blank)
1412 skb->ip_summed = CHECKSUM_PARTIAL;
1413 else if (txp->flags & XEN_NETTXF_data_validated)
1414 skb->ip_summed = CHECKSUM_UNNECESSARY;
1416 xenvif_fill_frags(vif, skb);
1418 if (unlikely(skb_has_frag_list(skb))) {
1419 if (xenvif_handle_frag_list(vif, skb)) {
1420 if (net_ratelimit())
1421 netdev_err(vif->dev,
1422 "Not enough memory to consolidate frag_list!\n");
1423 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1429 if (skb_is_nonlinear(skb) && skb_headlen(skb) < PKT_PROT_LEN) {
1430 int target = min_t(int, skb->len, PKT_PROT_LEN);
1431 __pskb_pull_tail(skb, target - skb_headlen(skb));
1434 skb->dev = vif->dev;
1435 skb->protocol = eth_type_trans(skb, skb->dev);
1436 skb_reset_network_header(skb);
1438 if (checksum_setup(vif, skb)) {
1439 netdev_dbg(vif->dev,
1440 "Can't setup checksum in net_tx_action\n");
1441 /* We have to set this flag to trigger the callback */
1442 if (skb_shinfo(skb)->destructor_arg)
1443 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1448 skb_probe_transport_header(skb, 0);
1450 /* If the packet is GSO then we will have just set up the
1451 * transport header offset in checksum_setup so it's now
1452 * straightforward to calculate gso_segs.
1454 if (skb_is_gso(skb)) {
1455 int mss = skb_shinfo(skb)->gso_size;
1456 int hdrlen = skb_transport_header(skb) -
1457 skb_mac_header(skb) +
1460 skb_shinfo(skb)->gso_segs =
1461 DIV_ROUND_UP(skb->len - hdrlen, mss);
1464 vif->dev->stats.rx_bytes += skb->len;
1465 vif->dev->stats.rx_packets++;
1469 /* Set this flag right before netif_receive_skb, otherwise
1470 * someone might think this packet already left netback, and
1471 * do a skb_copy_ubufs while we are still in control of the
1472 * skb. E.g. the __pskb_pull_tail earlier can do such thing.
1474 if (skb_shinfo(skb)->destructor_arg) {
1475 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1476 vif->tx_zerocopy_sent++;
1479 netif_receive_skb(skb);
1485 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success)
1487 unsigned long flags;
1488 pending_ring_idx_t index;
1489 struct xenvif *vif = ubuf_to_vif(ubuf);
1491 /* This is the only place where we grab this lock, to protect callbacks
1494 spin_lock_irqsave(&vif->callback_lock, flags);
1496 u16 pending_idx = ubuf->desc;
1497 ubuf = (struct ubuf_info *) ubuf->ctx;
1498 BUG_ON(vif->dealloc_prod - vif->dealloc_cons >=
1500 index = pending_index(vif->dealloc_prod);
1501 vif->dealloc_ring[index] = pending_idx;
1502 /* Sync with xenvif_tx_dealloc_action:
1503 * insert idx then incr producer.
1506 vif->dealloc_prod++;
1508 wake_up(&vif->dealloc_wq);
1509 spin_unlock_irqrestore(&vif->callback_lock, flags);
1511 if (RING_HAS_UNCONSUMED_REQUESTS(&vif->tx) &&
1512 xenvif_tx_pending_slots_available(vif)) {
1514 napi_schedule(&vif->napi);
1518 if (likely(zerocopy_success))
1519 vif->tx_zerocopy_success++;
1521 vif->tx_zerocopy_fail++;
1524 static inline void xenvif_tx_dealloc_action(struct xenvif *vif)
1526 struct gnttab_unmap_grant_ref *gop;
1527 pending_ring_idx_t dc, dp;
1528 u16 pending_idx, pending_idx_release[MAX_PENDING_REQS];
1531 dc = vif->dealloc_cons;
1532 gop = vif->tx_unmap_ops;
1534 /* Free up any grants we have finished using */
1536 dp = vif->dealloc_prod;
1538 /* Ensure we see all indices enqueued by all
1539 * xenvif_zerocopy_callback().
1544 BUG_ON(gop - vif->tx_unmap_ops > MAX_PENDING_REQS);
1546 vif->dealloc_ring[pending_index(dc++)];
1548 pending_idx_release[gop-vif->tx_unmap_ops] =
1550 vif->pages_to_unmap[gop-vif->tx_unmap_ops] =
1551 vif->mmap_pages[pending_idx];
1552 gnttab_set_unmap_op(gop,
1553 idx_to_kaddr(vif, pending_idx),
1555 vif->grant_tx_handle[pending_idx]);
1556 /* Btw. already unmapped? */
1557 xenvif_grant_handle_reset(vif, pending_idx);
1561 } while (dp != vif->dealloc_prod);
1563 vif->dealloc_cons = dc;
1565 if (gop - vif->tx_unmap_ops > 0) {
1567 ret = gnttab_unmap_refs(vif->tx_unmap_ops,
1569 vif->pages_to_unmap,
1570 gop - vif->tx_unmap_ops);
1572 netdev_err(vif->dev, "Unmap fail: nr_ops %tx ret %d\n",
1573 gop - vif->tx_unmap_ops, ret);
1574 for (i = 0; i < gop - vif->tx_unmap_ops; ++i) {
1575 if (gop[i].status != GNTST_okay)
1576 netdev_err(vif->dev,
1577 " host_addr: %llx handle: %x status: %d\n",
1586 for (i = 0; i < gop - vif->tx_unmap_ops; ++i)
1587 xenvif_idx_release(vif, pending_idx_release[i],
1588 XEN_NETIF_RSP_OKAY);
1592 /* Called after netfront has transmitted */
1593 int xenvif_tx_action(struct xenvif *vif, int budget)
1598 if (unlikely(!tx_work_todo(vif)))
1601 nr_gops = xenvif_tx_build_gops(vif, budget);
1606 ret = gnttab_map_refs(vif->tx_map_ops,
1612 work_done = xenvif_tx_submit(vif);
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 index;
1622 unsigned long flags;
1624 pending_tx_info = &vif->pending_tx_info[pending_idx];
1625 spin_lock_irqsave(&vif->response_lock, flags);
1626 make_tx_response(vif, &pending_tx_info->req, status);
1627 index = pending_index(vif->pending_prod);
1628 vif->pending_ring[index] = pending_idx;
1629 /* TX shouldn't use the index before we give it back here */
1631 vif->pending_prod++;
1632 spin_unlock_irqrestore(&vif->response_lock, flags);
1636 static void make_tx_response(struct xenvif *vif,
1637 struct xen_netif_tx_request *txp,
1640 RING_IDX i = vif->tx.rsp_prod_pvt;
1641 struct xen_netif_tx_response *resp;
1644 resp = RING_GET_RESPONSE(&vif->tx, i);
1648 if (txp->flags & XEN_NETTXF_extra_info)
1649 RING_GET_RESPONSE(&vif->tx, ++i)->status = XEN_NETIF_RSP_NULL;
1651 vif->tx.rsp_prod_pvt = ++i;
1652 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->tx, notify);
1654 notify_remote_via_irq(vif->tx_irq);
1657 static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif,
1664 RING_IDX i = vif->rx.rsp_prod_pvt;
1665 struct xen_netif_rx_response *resp;
1667 resp = RING_GET_RESPONSE(&vif->rx, i);
1668 resp->offset = offset;
1669 resp->flags = flags;
1671 resp->status = (s16)size;
1673 resp->status = (s16)st;
1675 vif->rx.rsp_prod_pvt = ++i;
1680 void xenvif_idx_unmap(struct xenvif *vif, u16 pending_idx)
1683 struct gnttab_unmap_grant_ref tx_unmap_op;
1685 gnttab_set_unmap_op(&tx_unmap_op,
1686 idx_to_kaddr(vif, pending_idx),
1688 vif->grant_tx_handle[pending_idx]);
1689 /* Btw. already unmapped? */
1690 xenvif_grant_handle_reset(vif, pending_idx);
1692 ret = gnttab_unmap_refs(&tx_unmap_op, NULL,
1693 &vif->mmap_pages[pending_idx], 1);
1696 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY);
1699 static inline int rx_work_todo(struct xenvif *vif)
1701 return (!skb_queue_empty(&vif->rx_queue) &&
1702 xenvif_rx_ring_slots_available(vif, vif->rx_last_skb_slots)) ||
1703 vif->rx_queue_purge;
1706 static inline int tx_work_todo(struct xenvif *vif)
1709 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->tx)) &&
1710 xenvif_tx_pending_slots_available(vif))
1716 static inline bool tx_dealloc_work_todo(struct xenvif *vif)
1718 return vif->dealloc_cons != vif->dealloc_prod;
1721 void xenvif_unmap_frontend_rings(struct xenvif *vif)
1724 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
1727 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
1731 int xenvif_map_frontend_rings(struct xenvif *vif,
1732 grant_ref_t tx_ring_ref,
1733 grant_ref_t rx_ring_ref)
1736 struct xen_netif_tx_sring *txs;
1737 struct xen_netif_rx_sring *rxs;
1741 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
1742 tx_ring_ref, &addr);
1746 txs = (struct xen_netif_tx_sring *)addr;
1747 BACK_RING_INIT(&vif->tx, txs, PAGE_SIZE);
1749 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
1750 rx_ring_ref, &addr);
1754 rxs = (struct xen_netif_rx_sring *)addr;
1755 BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE);
1760 xenvif_unmap_frontend_rings(vif);
1764 void xenvif_stop_queue(struct xenvif *vif)
1766 if (!vif->can_queue)
1769 netif_stop_queue(vif->dev);
1772 static void xenvif_start_queue(struct xenvif *vif)
1774 if (xenvif_schedulable(vif))
1775 netif_wake_queue(vif->dev);
1778 int xenvif_kthread_guest_rx(void *data)
1780 struct xenvif *vif = data;
1781 struct sk_buff *skb;
1783 while (!kthread_should_stop()) {
1784 wait_event_interruptible(vif->wq,
1785 rx_work_todo(vif) ||
1786 kthread_should_stop());
1787 if (kthread_should_stop())
1790 if (vif->rx_queue_purge) {
1791 skb_queue_purge(&vif->rx_queue);
1792 vif->rx_queue_purge = false;
1795 if (!skb_queue_empty(&vif->rx_queue))
1796 xenvif_rx_action(vif);
1798 if (skb_queue_empty(&vif->rx_queue) &&
1799 netif_queue_stopped(vif->dev)) {
1800 del_timer_sync(&vif->wake_queue);
1801 xenvif_start_queue(vif);
1807 /* Bin any remaining skbs */
1808 while ((skb = skb_dequeue(&vif->rx_queue)) != NULL)
1814 int xenvif_dealloc_kthread(void *data)
1816 struct xenvif *vif = data;
1818 while (!kthread_should_stop()) {
1819 wait_event_interruptible(vif->dealloc_wq,
1820 tx_dealloc_work_todo(vif) ||
1821 kthread_should_stop());
1822 if (kthread_should_stop())
1825 xenvif_tx_dealloc_action(vif);
1829 /* Unmap anything remaining*/
1830 if (tx_dealloc_work_todo(vif))
1831 xenvif_tx_dealloc_action(vif);
1836 static int __init netback_init(void)
1843 if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
1844 pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
1845 fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX);
1846 fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX;
1849 rc = xenvif_xenbus_init();
1853 rx_drain_timeout_jiffies = msecs_to_jiffies(rx_drain_timeout_msecs);
1861 module_init(netback_init);
1863 static void __exit netback_fini(void)
1865 xenvif_xenbus_fini();
1867 module_exit(netback_fini);
1869 MODULE_LICENSE("Dual BSD/GPL");
1870 MODULE_ALIAS("xen-backend:vif");