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 stuck 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 #define callback_param(vif, pending_idx) \
103 (vif->pending_tx_info[pending_idx].callback_struct)
105 /* Find the containing VIF's structure from a pointer in pending_tx_info array
107 static inline struct xenvif* ubuf_to_vif(struct ubuf_info *ubuf)
109 u16 pending_idx = ubuf->desc;
110 struct pending_tx_info *temp =
111 container_of(ubuf, struct pending_tx_info, callback_struct);
112 return container_of(temp - pending_idx,
117 /* This is a miniumum size for the linear area to avoid lots of
118 * calls to __pskb_pull_tail() as we set up checksum offsets. The
119 * value 128 was chosen as it covers all IPv4 and most likely
122 #define PKT_PROT_LEN 128
124 static u16 frag_get_pending_idx(skb_frag_t *frag)
126 return (u16)frag->page_offset;
129 static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx)
131 frag->page_offset = pending_idx;
134 static inline pending_ring_idx_t pending_index(unsigned i)
136 return i & (MAX_PENDING_REQS-1);
139 bool xenvif_rx_ring_slots_available(struct xenvif *vif, int needed)
144 prod = vif->rx.sring->req_prod;
145 cons = vif->rx.req_cons;
147 if (prod - cons >= needed)
150 vif->rx.sring->req_event = prod + 1;
152 /* Make sure event is visible before we check prod
156 } while (vif->rx.sring->req_prod != prod);
162 * Returns true if we should start a new receive buffer instead of
163 * adding 'size' bytes to a buffer which currently contains 'offset'
166 static bool start_new_rx_buffer(int offset, unsigned long size, int head)
168 /* simple case: we have completely filled the current buffer. */
169 if (offset == MAX_BUFFER_OFFSET)
173 * complex case: start a fresh buffer if the current frag
174 * would overflow the current buffer but only if:
175 * (i) this frag would fit completely in the next buffer
176 * and (ii) there is already some data in the current buffer
177 * and (iii) this is not the head buffer.
180 * - (i) stops us splitting a frag into two copies
181 * unless the frag is too large for a single buffer.
182 * - (ii) stops us from leaving a buffer pointlessly empty.
183 * - (iii) stops us leaving the first buffer
184 * empty. Strictly speaking this is already covered
185 * by (ii) but is explicitly checked because
186 * netfront relies on the first buffer being
187 * non-empty and can crash otherwise.
189 * This means we will effectively linearise small
190 * frags but do not needlessly split large buffers
191 * into multiple copies tend to give large frags their
192 * own buffers as before.
194 BUG_ON(size > MAX_BUFFER_OFFSET);
195 if ((offset + size > MAX_BUFFER_OFFSET) && offset && !head)
201 struct netrx_pending_operations {
202 unsigned copy_prod, copy_cons;
203 unsigned meta_prod, meta_cons;
204 struct gnttab_copy *copy;
205 struct xenvif_rx_meta *meta;
207 grant_ref_t copy_gref;
210 static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif *vif,
211 struct netrx_pending_operations *npo)
213 struct xenvif_rx_meta *meta;
214 struct xen_netif_rx_request *req;
216 req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
218 meta = npo->meta + npo->meta_prod++;
219 meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
225 npo->copy_gref = req->gref;
231 * Set up the grant operations for this fragment. If it's a flipping
232 * interface, we also set up the unmap request from here.
234 static void xenvif_gop_frag_copy(struct xenvif *vif, struct sk_buff *skb,
235 struct netrx_pending_operations *npo,
236 struct page *page, unsigned long size,
237 unsigned long offset, int *head,
238 struct xenvif *foreign_vif,
239 grant_ref_t foreign_gref)
241 struct gnttab_copy *copy_gop;
242 struct xenvif_rx_meta *meta;
244 int gso_type = XEN_NETIF_GSO_TYPE_NONE;
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;
282 copy_gop->source.domid = foreign_vif->domid;
283 copy_gop->source.u.ref = foreign_gref;
284 copy_gop->flags |= GNTCOPY_source_gref;
286 copy_gop->source.domid = DOMID_SELF;
287 copy_gop->source.u.gmfn =
288 virt_to_mfn(page_address(page));
290 copy_gop->source.offset = offset;
292 copy_gop->dest.domid = vif->domid;
293 copy_gop->dest.offset = npo->copy_off;
294 copy_gop->dest.u.ref = npo->copy_gref;
296 npo->copy_off += bytes;
303 if (offset == PAGE_SIZE && size) {
304 BUG_ON(!PageCompound(page));
309 /* Leave a gap for the GSO descriptor. */
310 if (skb_is_gso(skb)) {
311 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
312 gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
313 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
314 gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
317 if (*head && ((1 << gso_type) & vif->gso_mask))
320 *head = 0; /* There must be something in this buffer now. */
326 * Prepare an SKB to be transmitted to the frontend.
328 * This function is responsible for allocating grant operations, meta
331 * It returns the number of meta structures consumed. The number of
332 * ring slots used is always equal to the number of meta slots used
333 * plus the number of GSO descriptors used. Currently, we use either
334 * zero GSO descriptors (for non-GSO packets) or one descriptor (for
335 * frontend-side LRO).
337 static int xenvif_gop_skb(struct sk_buff *skb,
338 struct netrx_pending_operations *npo)
340 struct xenvif *vif = netdev_priv(skb->dev);
341 int nr_frags = skb_shinfo(skb)->nr_frags;
343 struct xen_netif_rx_request *req;
344 struct xenvif_rx_meta *meta;
349 struct ubuf_info *ubuf = skb_shinfo(skb)->destructor_arg;
350 grant_ref_t foreign_grefs[MAX_SKB_FRAGS];
351 struct xenvif *foreign_vif = NULL;
353 old_meta_prod = npo->meta_prod;
355 gso_type = XEN_NETIF_GSO_TYPE_NONE;
356 if (skb_is_gso(skb)) {
357 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
358 gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
359 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
360 gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
363 /* Set up a GSO prefix descriptor, if necessary */
364 if ((1 << gso_type) & vif->gso_prefix_mask) {
365 req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
366 meta = npo->meta + npo->meta_prod++;
367 meta->gso_type = gso_type;
368 meta->gso_size = skb_shinfo(skb)->gso_size;
373 req = RING_GET_REQUEST(&vif->rx, vif->rx.req_cons++);
374 meta = npo->meta + npo->meta_prod++;
376 if ((1 << gso_type) & vif->gso_mask) {
377 meta->gso_type = gso_type;
378 meta->gso_size = skb_shinfo(skb)->gso_size;
380 meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
387 npo->copy_gref = req->gref;
389 if ((skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) &&
390 (ubuf->callback == &xenvif_zerocopy_callback)) {
392 foreign_vif = ubuf_to_vif(ubuf);
395 u16 pending_idx = ubuf->desc;
397 foreign_vif->pending_tx_info[pending_idx].req.gref;
398 ubuf = (struct ubuf_info *) ubuf->ctx;
403 while (data < skb_tail_pointer(skb)) {
404 unsigned int offset = offset_in_page(data);
405 unsigned int len = PAGE_SIZE - offset;
407 if (data + len > skb_tail_pointer(skb))
408 len = skb_tail_pointer(skb) - data;
410 xenvif_gop_frag_copy(vif, skb, npo,
411 virt_to_page(data), len, offset, &head,
417 for (i = 0; i < nr_frags; i++) {
418 xenvif_gop_frag_copy(vif, skb, npo,
419 skb_frag_page(&skb_shinfo(skb)->frags[i]),
420 skb_frag_size(&skb_shinfo(skb)->frags[i]),
421 skb_shinfo(skb)->frags[i].page_offset,
427 return npo->meta_prod - old_meta_prod;
431 * This is a twin to xenvif_gop_skb. Assume that xenvif_gop_skb was
432 * used to set up the operations on the top of
433 * netrx_pending_operations, which have since been done. Check that
434 * they didn't give any errors and advance over them.
436 static int xenvif_check_gop(struct xenvif *vif, int nr_meta_slots,
437 struct netrx_pending_operations *npo)
439 struct gnttab_copy *copy_op;
440 int status = XEN_NETIF_RSP_OKAY;
443 for (i = 0; i < nr_meta_slots; i++) {
444 copy_op = npo->copy + npo->copy_cons++;
445 if (copy_op->status != GNTST_okay) {
447 "Bad status %d from copy to DOM%d.\n",
448 copy_op->status, vif->domid);
449 status = XEN_NETIF_RSP_ERROR;
456 static void xenvif_add_frag_responses(struct xenvif *vif, int status,
457 struct xenvif_rx_meta *meta,
461 unsigned long offset;
463 /* No fragments used */
464 if (nr_meta_slots <= 1)
469 for (i = 0; i < nr_meta_slots; i++) {
471 if (i == nr_meta_slots - 1)
474 flags = XEN_NETRXF_more_data;
477 make_rx_response(vif, meta[i].id, status, offset,
478 meta[i].size, flags);
482 struct xenvif_rx_cb {
486 #define XENVIF_RX_CB(skb) ((struct xenvif_rx_cb *)(skb)->cb)
488 void xenvif_kick_thread(struct xenvif *vif)
493 static void xenvif_rx_action(struct xenvif *vif)
497 struct xen_netif_rx_response *resp;
498 struct sk_buff_head rxq;
502 unsigned long offset;
503 bool need_to_notify = false;
505 struct netrx_pending_operations npo = {
506 .copy = vif->grant_copy_op,
510 skb_queue_head_init(&rxq);
512 while ((skb = skb_dequeue(&vif->rx_queue)) != NULL) {
513 RING_IDX max_slots_needed;
514 RING_IDX old_req_cons;
515 RING_IDX ring_slots_used;
518 /* We need a cheap worse case estimate for the number of
522 max_slots_needed = DIV_ROUND_UP(offset_in_page(skb->data) +
525 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
529 size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
530 offset = skb_shinfo(skb)->frags[i].page_offset;
532 /* For a worse-case estimate we need to factor in
533 * the fragment page offset as this will affect the
534 * number of times xenvif_gop_frag_copy() will
535 * call start_new_rx_buffer().
537 max_slots_needed += DIV_ROUND_UP(offset + size,
541 /* To avoid the estimate becoming too pessimal for some
542 * frontends that limit posted rx requests, cap the estimate
545 if (max_slots_needed > MAX_SKB_FRAGS)
546 max_slots_needed = MAX_SKB_FRAGS;
548 /* We may need one more slot for GSO metadata */
549 if (skb_is_gso(skb) &&
550 (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4 ||
551 skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6))
554 /* If the skb may not fit then bail out now */
555 if (!xenvif_rx_ring_slots_available(vif, max_slots_needed)) {
556 skb_queue_head(&vif->rx_queue, skb);
557 need_to_notify = true;
558 vif->rx_last_skb_slots = max_slots_needed;
561 vif->rx_last_skb_slots = 0;
563 old_req_cons = vif->rx.req_cons;
564 XENVIF_RX_CB(skb)->meta_slots_used = xenvif_gop_skb(skb, &npo);
565 ring_slots_used = vif->rx.req_cons - old_req_cons;
567 BUG_ON(ring_slots_used > max_slots_needed);
569 __skb_queue_tail(&rxq, skb);
572 BUG_ON(npo.meta_prod > ARRAY_SIZE(vif->meta));
577 BUG_ON(npo.copy_prod > MAX_GRANT_COPY_OPS);
578 gnttab_batch_copy(vif->grant_copy_op, npo.copy_prod);
580 while ((skb = __skb_dequeue(&rxq)) != NULL) {
582 if ((1 << vif->meta[npo.meta_cons].gso_type) &
583 vif->gso_prefix_mask) {
584 resp = RING_GET_RESPONSE(&vif->rx,
585 vif->rx.rsp_prod_pvt++);
587 resp->flags = XEN_NETRXF_gso_prefix | XEN_NETRXF_more_data;
589 resp->offset = vif->meta[npo.meta_cons].gso_size;
590 resp->id = vif->meta[npo.meta_cons].id;
591 resp->status = XENVIF_RX_CB(skb)->meta_slots_used;
594 XENVIF_RX_CB(skb)->meta_slots_used--;
598 vif->dev->stats.tx_bytes += skb->len;
599 vif->dev->stats.tx_packets++;
601 status = xenvif_check_gop(vif,
602 XENVIF_RX_CB(skb)->meta_slots_used,
605 if (XENVIF_RX_CB(skb)->meta_slots_used == 1)
608 flags = XEN_NETRXF_more_data;
610 if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */
611 flags |= XEN_NETRXF_csum_blank | XEN_NETRXF_data_validated;
612 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
613 /* remote but checksummed. */
614 flags |= XEN_NETRXF_data_validated;
617 resp = make_rx_response(vif, vif->meta[npo.meta_cons].id,
619 vif->meta[npo.meta_cons].size,
622 if ((1 << vif->meta[npo.meta_cons].gso_type) &
624 struct xen_netif_extra_info *gso =
625 (struct xen_netif_extra_info *)
626 RING_GET_RESPONSE(&vif->rx,
627 vif->rx.rsp_prod_pvt++);
629 resp->flags |= XEN_NETRXF_extra_info;
631 gso->u.gso.type = vif->meta[npo.meta_cons].gso_type;
632 gso->u.gso.size = vif->meta[npo.meta_cons].gso_size;
634 gso->u.gso.features = 0;
636 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
640 xenvif_add_frag_responses(vif, status,
641 vif->meta + npo.meta_cons + 1,
642 XENVIF_RX_CB(skb)->meta_slots_used);
644 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->rx, ret);
646 need_to_notify |= !!ret;
648 npo.meta_cons += XENVIF_RX_CB(skb)->meta_slots_used;
654 notify_remote_via_irq(vif->rx_irq);
657 void xenvif_check_rx_xenvif(struct xenvif *vif)
661 RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do);
664 napi_schedule(&vif->napi);
667 static void tx_add_credit(struct xenvif *vif)
669 unsigned long max_burst, max_credit;
672 * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
673 * Otherwise the interface can seize up due to insufficient credit.
675 max_burst = RING_GET_REQUEST(&vif->tx, vif->tx.req_cons)->size;
676 max_burst = min(max_burst, 131072UL);
677 max_burst = max(max_burst, vif->credit_bytes);
679 /* Take care that adding a new chunk of credit doesn't wrap to zero. */
680 max_credit = vif->remaining_credit + vif->credit_bytes;
681 if (max_credit < vif->remaining_credit)
682 max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
684 vif->remaining_credit = min(max_credit, max_burst);
687 static void tx_credit_callback(unsigned long data)
689 struct xenvif *vif = (struct xenvif *)data;
691 xenvif_check_rx_xenvif(vif);
694 static void xenvif_tx_err(struct xenvif *vif,
695 struct xen_netif_tx_request *txp, RING_IDX end)
697 RING_IDX cons = vif->tx.req_cons;
701 spin_lock_irqsave(&vif->response_lock, flags);
702 make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR);
703 spin_unlock_irqrestore(&vif->response_lock, flags);
706 txp = RING_GET_REQUEST(&vif->tx, cons++);
708 vif->tx.req_cons = cons;
711 static void xenvif_fatal_tx_err(struct xenvif *vif)
713 netdev_err(vif->dev, "fatal error; disabling device\n");
714 vif->disabled = true;
715 xenvif_kick_thread(vif);
718 static int xenvif_count_requests(struct xenvif *vif,
719 struct xen_netif_tx_request *first,
720 struct xen_netif_tx_request *txp,
723 RING_IDX cons = vif->tx.req_cons;
728 if (!(first->flags & XEN_NETTXF_more_data))
732 struct xen_netif_tx_request dropped_tx = { 0 };
734 if (slots >= work_to_do) {
736 "Asked for %d slots but exceeds this limit\n",
738 xenvif_fatal_tx_err(vif);
742 /* This guest is really using too many slots and
743 * considered malicious.
745 if (unlikely(slots >= fatal_skb_slots)) {
747 "Malicious frontend using %d slots, threshold %u\n",
748 slots, fatal_skb_slots);
749 xenvif_fatal_tx_err(vif);
753 /* Xen network protocol had implicit dependency on
754 * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to
755 * the historical MAX_SKB_FRAGS value 18 to honor the
756 * same behavior as before. Any packet using more than
757 * 18 slots but less than fatal_skb_slots slots is
760 if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) {
763 "Too many slots (%d) exceeding limit (%d), dropping packet\n",
764 slots, XEN_NETBK_LEGACY_SLOTS_MAX);
771 memcpy(txp, RING_GET_REQUEST(&vif->tx, cons + slots),
774 /* If the guest submitted a frame >= 64 KiB then
775 * first->size overflowed and following slots will
776 * appear to be larger than the frame.
778 * This cannot be fatal error as there are buggy
779 * frontends that do this.
781 * Consume all slots and drop the packet.
783 if (!drop_err && txp->size > first->size) {
786 "Invalid tx request, slot size %u > remaining size %u\n",
787 txp->size, first->size);
791 first->size -= txp->size;
794 if (unlikely((txp->offset + txp->size) > PAGE_SIZE)) {
795 netdev_err(vif->dev, "Cross page boundary, txp->offset: %x, size: %u\n",
796 txp->offset, txp->size);
797 xenvif_fatal_tx_err(vif);
801 more_data = txp->flags & XEN_NETTXF_more_data;
809 xenvif_tx_err(vif, first, cons + slots);
817 struct xenvif_tx_cb {
821 #define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb)
823 static inline void xenvif_tx_create_gop(struct xenvif *vif,
825 struct xen_netif_tx_request *txp,
826 struct gnttab_map_grant_ref *gop)
828 vif->pages_to_map[gop-vif->tx_map_ops] = vif->mmap_pages[pending_idx];
829 gnttab_set_map_op(gop, idx_to_kaddr(vif, pending_idx),
830 GNTMAP_host_map | GNTMAP_readonly,
831 txp->gref, vif->domid);
833 memcpy(&vif->pending_tx_info[pending_idx].req, txp,
837 static inline struct sk_buff *xenvif_alloc_skb(unsigned int size)
839 struct sk_buff *skb =
840 alloc_skb(size + NET_SKB_PAD + NET_IP_ALIGN,
841 GFP_ATOMIC | __GFP_NOWARN);
842 if (unlikely(skb == NULL))
845 /* Packets passed to netif_rx() must have some headroom. */
846 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
848 /* Initialize it here to avoid later surprises */
849 skb_shinfo(skb)->destructor_arg = NULL;
854 static struct gnttab_map_grant_ref *xenvif_get_requests(struct xenvif *vif,
856 struct xen_netif_tx_request *txp,
857 struct gnttab_map_grant_ref *gop)
859 struct skb_shared_info *shinfo = skb_shinfo(skb);
860 skb_frag_t *frags = shinfo->frags;
861 u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
863 pending_ring_idx_t index;
864 unsigned int nr_slots, frag_overflow = 0;
866 /* At this point shinfo->nr_frags is in fact the number of
867 * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
869 if (shinfo->nr_frags > MAX_SKB_FRAGS) {
870 frag_overflow = shinfo->nr_frags - MAX_SKB_FRAGS;
871 BUG_ON(frag_overflow > MAX_SKB_FRAGS);
872 shinfo->nr_frags = MAX_SKB_FRAGS;
874 nr_slots = shinfo->nr_frags;
876 /* Skip first skb fragment if it is on same page as header fragment. */
877 start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
879 for (shinfo->nr_frags = start; shinfo->nr_frags < nr_slots;
880 shinfo->nr_frags++, txp++, gop++) {
881 index = pending_index(vif->pending_cons++);
882 pending_idx = vif->pending_ring[index];
883 xenvif_tx_create_gop(vif, pending_idx, txp, gop);
884 frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx);
888 struct sk_buff *nskb = xenvif_alloc_skb(0);
889 if (unlikely(nskb == NULL)) {
892 "Can't allocate the frag_list skb.\n");
896 shinfo = skb_shinfo(nskb);
897 frags = shinfo->frags;
899 for (shinfo->nr_frags = 0; shinfo->nr_frags < frag_overflow;
900 shinfo->nr_frags++, txp++, gop++) {
901 index = pending_index(vif->pending_cons++);
902 pending_idx = vif->pending_ring[index];
903 xenvif_tx_create_gop(vif, pending_idx, txp, gop);
904 frag_set_pending_idx(&frags[shinfo->nr_frags],
908 skb_shinfo(skb)->frag_list = nskb;
914 static inline void xenvif_grant_handle_set(struct xenvif *vif,
916 grant_handle_t handle)
918 if (unlikely(vif->grant_tx_handle[pending_idx] !=
919 NETBACK_INVALID_HANDLE)) {
921 "Trying to overwrite active handle! pending_idx: %x\n",
925 vif->grant_tx_handle[pending_idx] = handle;
928 static inline void xenvif_grant_handle_reset(struct xenvif *vif,
931 if (unlikely(vif->grant_tx_handle[pending_idx] ==
932 NETBACK_INVALID_HANDLE)) {
934 "Trying to unmap invalid handle! pending_idx: %x\n",
938 vif->grant_tx_handle[pending_idx] = NETBACK_INVALID_HANDLE;
941 static int xenvif_tx_check_gop(struct xenvif *vif,
943 struct gnttab_map_grant_ref **gopp)
945 struct gnttab_map_grant_ref *gop = *gopp;
946 u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
947 struct skb_shared_info *shinfo = skb_shinfo(skb);
948 struct pending_tx_info *tx_info;
949 int nr_frags = shinfo->nr_frags;
951 struct sk_buff *first_skb = NULL;
953 /* Check status of header. */
956 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR);
958 xenvif_grant_handle_set(vif, pending_idx , gop->handle);
960 /* Skip first skb fragment if it is on same page as header fragment. */
961 start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
964 for (i = start; i < nr_frags; i++) {
967 pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
968 tx_info = &vif->pending_tx_info[pending_idx];
970 /* Check error status: if okay then remember grant handle. */
971 newerr = (++gop)->status;
973 if (likely(!newerr)) {
974 xenvif_grant_handle_set(vif, pending_idx , gop->handle);
975 /* Had a previous error? Invalidate this fragment. */
977 xenvif_idx_unmap(vif, pending_idx);
981 /* Error on this fragment: respond to client with an error. */
982 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_ERROR);
984 /* Not the first error? Preceding frags already invalidated. */
987 /* First error: invalidate header and preceding fragments. */
989 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
991 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
992 xenvif_idx_unmap(vif, pending_idx);
993 for (j = start; j < i; j++) {
994 pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
995 xenvif_idx_unmap(vif, pending_idx);
998 /* Remember the error: invalidate all subsequent fragments. */
1002 if (skb_has_frag_list(skb)) {
1004 skb = shinfo->frag_list;
1005 shinfo = skb_shinfo(skb);
1006 nr_frags = shinfo->nr_frags;
1012 /* There was a mapping error in the frag_list skb. We have to unmap
1013 * the first skb's frags
1015 if (first_skb && err) {
1017 shinfo = skb_shinfo(first_skb);
1018 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
1019 start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
1020 for (j = start; j < shinfo->nr_frags; j++) {
1021 pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
1022 xenvif_idx_unmap(vif, pending_idx);
1030 static void xenvif_fill_frags(struct xenvif *vif, struct sk_buff *skb)
1032 struct skb_shared_info *shinfo = skb_shinfo(skb);
1033 int nr_frags = shinfo->nr_frags;
1035 u16 prev_pending_idx = INVALID_PENDING_IDX;
1037 if (skb_shinfo(skb)->destructor_arg)
1038 prev_pending_idx = XENVIF_TX_CB(skb)->pending_idx;
1040 for (i = 0; i < nr_frags; i++) {
1041 skb_frag_t *frag = shinfo->frags + i;
1042 struct xen_netif_tx_request *txp;
1046 pending_idx = frag_get_pending_idx(frag);
1048 /* If this is not the first frag, chain it to the previous*/
1049 if (unlikely(prev_pending_idx == INVALID_PENDING_IDX))
1050 skb_shinfo(skb)->destructor_arg =
1051 &callback_param(vif, pending_idx);
1052 else if (likely(pending_idx != prev_pending_idx))
1053 callback_param(vif, prev_pending_idx).ctx =
1054 &callback_param(vif, pending_idx);
1056 callback_param(vif, pending_idx).ctx = NULL;
1057 prev_pending_idx = pending_idx;
1059 txp = &vif->pending_tx_info[pending_idx].req;
1060 page = virt_to_page(idx_to_kaddr(vif, pending_idx));
1061 __skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
1062 skb->len += txp->size;
1063 skb->data_len += txp->size;
1064 skb->truesize += txp->size;
1066 /* Take an extra reference to offset network stack's put_page */
1067 get_page(vif->mmap_pages[pending_idx]);
1069 /* FIXME: __skb_fill_page_desc set this to true because page->pfmemalloc
1070 * overlaps with "index", and "mapping" is not set. I think mapping
1071 * should be set. If delivered to local stack, it would drop this
1072 * skb in sk_filter unless the socket has the right to use it.
1074 skb->pfmemalloc = false;
1077 static int xenvif_get_extras(struct xenvif *vif,
1078 struct xen_netif_extra_info *extras,
1081 struct xen_netif_extra_info extra;
1082 RING_IDX cons = vif->tx.req_cons;
1085 if (unlikely(work_to_do-- <= 0)) {
1086 netdev_err(vif->dev, "Missing extra info\n");
1087 xenvif_fatal_tx_err(vif);
1091 memcpy(&extra, RING_GET_REQUEST(&vif->tx, cons),
1093 if (unlikely(!extra.type ||
1094 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
1095 vif->tx.req_cons = ++cons;
1096 netdev_err(vif->dev,
1097 "Invalid extra type: %d\n", extra.type);
1098 xenvif_fatal_tx_err(vif);
1102 memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
1103 vif->tx.req_cons = ++cons;
1104 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
1109 static int xenvif_set_skb_gso(struct xenvif *vif,
1110 struct sk_buff *skb,
1111 struct xen_netif_extra_info *gso)
1113 if (!gso->u.gso.size) {
1114 netdev_err(vif->dev, "GSO size must not be zero.\n");
1115 xenvif_fatal_tx_err(vif);
1119 switch (gso->u.gso.type) {
1120 case XEN_NETIF_GSO_TYPE_TCPV4:
1121 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1123 case XEN_NETIF_GSO_TYPE_TCPV6:
1124 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1127 netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
1128 xenvif_fatal_tx_err(vif);
1132 skb_shinfo(skb)->gso_size = gso->u.gso.size;
1133 /* gso_segs will be calculated later */
1138 static int checksum_setup(struct xenvif *vif, struct sk_buff *skb)
1140 bool recalculate_partial_csum = false;
1142 /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
1143 * peers can fail to set NETRXF_csum_blank when sending a GSO
1144 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
1145 * recalculate the partial checksum.
1147 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
1148 vif->rx_gso_checksum_fixup++;
1149 skb->ip_summed = CHECKSUM_PARTIAL;
1150 recalculate_partial_csum = true;
1153 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
1154 if (skb->ip_summed != CHECKSUM_PARTIAL)
1157 return skb_checksum_setup(skb, recalculate_partial_csum);
1160 static bool tx_credit_exceeded(struct xenvif *vif, unsigned size)
1162 u64 now = get_jiffies_64();
1163 u64 next_credit = vif->credit_window_start +
1164 msecs_to_jiffies(vif->credit_usec / 1000);
1166 /* Timer could already be pending in rare cases. */
1167 if (timer_pending(&vif->credit_timeout))
1170 /* Passed the point where we can replenish credit? */
1171 if (time_after_eq64(now, next_credit)) {
1172 vif->credit_window_start = now;
1176 /* Still too big to send right now? Set a callback. */
1177 if (size > vif->remaining_credit) {
1178 vif->credit_timeout.data =
1180 vif->credit_timeout.function =
1182 mod_timer(&vif->credit_timeout,
1184 vif->credit_window_start = next_credit;
1192 static unsigned xenvif_tx_build_gops(struct xenvif *vif, int budget)
1194 struct gnttab_map_grant_ref *gop = vif->tx_map_ops, *request_gop;
1195 struct sk_buff *skb;
1198 while (skb_queue_len(&vif->tx_queue) < budget) {
1199 struct xen_netif_tx_request txreq;
1200 struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
1201 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
1205 unsigned int data_len;
1206 pending_ring_idx_t index;
1208 if (vif->tx.sring->req_prod - vif->tx.req_cons >
1209 XEN_NETIF_TX_RING_SIZE) {
1210 netdev_err(vif->dev,
1211 "Impossible number of requests. "
1212 "req_prod %d, req_cons %d, size %ld\n",
1213 vif->tx.sring->req_prod, vif->tx.req_cons,
1214 XEN_NETIF_TX_RING_SIZE);
1215 xenvif_fatal_tx_err(vif);
1219 work_to_do = RING_HAS_UNCONSUMED_REQUESTS(&vif->tx);
1223 idx = vif->tx.req_cons;
1224 rmb(); /* Ensure that we see the request before we copy it. */
1225 memcpy(&txreq, RING_GET_REQUEST(&vif->tx, idx), sizeof(txreq));
1227 /* Credit-based scheduling. */
1228 if (txreq.size > vif->remaining_credit &&
1229 tx_credit_exceeded(vif, txreq.size))
1232 vif->remaining_credit -= txreq.size;
1235 vif->tx.req_cons = ++idx;
1237 memset(extras, 0, sizeof(extras));
1238 if (txreq.flags & XEN_NETTXF_extra_info) {
1239 work_to_do = xenvif_get_extras(vif, extras,
1241 idx = vif->tx.req_cons;
1242 if (unlikely(work_to_do < 0))
1246 ret = xenvif_count_requests(vif, &txreq, txfrags, work_to_do);
1247 if (unlikely(ret < 0))
1252 if (unlikely(txreq.size < ETH_HLEN)) {
1253 netdev_dbg(vif->dev,
1254 "Bad packet size: %d\n", txreq.size);
1255 xenvif_tx_err(vif, &txreq, idx);
1259 /* No crossing a page as the payload mustn't fragment. */
1260 if (unlikely((txreq.offset + txreq.size) > PAGE_SIZE)) {
1261 netdev_err(vif->dev,
1262 "txreq.offset: %x, size: %u, end: %lu\n",
1263 txreq.offset, txreq.size,
1264 (txreq.offset&~PAGE_MASK) + txreq.size);
1265 xenvif_fatal_tx_err(vif);
1269 index = pending_index(vif->pending_cons);
1270 pending_idx = vif->pending_ring[index];
1272 data_len = (txreq.size > PKT_PROT_LEN &&
1273 ret < XEN_NETBK_LEGACY_SLOTS_MAX) ?
1274 PKT_PROT_LEN : txreq.size;
1276 skb = xenvif_alloc_skb(data_len);
1277 if (unlikely(skb == NULL)) {
1278 netdev_dbg(vif->dev,
1279 "Can't allocate a skb in start_xmit.\n");
1280 xenvif_tx_err(vif, &txreq, idx);
1284 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1285 struct xen_netif_extra_info *gso;
1286 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1288 if (xenvif_set_skb_gso(vif, skb, gso)) {
1289 /* Failure in xenvif_set_skb_gso is fatal. */
1295 xenvif_tx_create_gop(vif, pending_idx, &txreq, gop);
1299 XENVIF_TX_CB(skb)->pending_idx = pending_idx;
1301 __skb_put(skb, data_len);
1303 skb_shinfo(skb)->nr_frags = ret;
1304 if (data_len < txreq.size) {
1305 skb_shinfo(skb)->nr_frags++;
1306 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
1309 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
1310 INVALID_PENDING_IDX);
1313 vif->pending_cons++;
1315 request_gop = xenvif_get_requests(vif, skb, txfrags, gop);
1316 if (request_gop == NULL) {
1318 xenvif_tx_err(vif, &txreq, idx);
1323 __skb_queue_tail(&vif->tx_queue, skb);
1325 vif->tx.req_cons = idx;
1327 if ((gop-vif->tx_map_ops) >= ARRAY_SIZE(vif->tx_map_ops))
1331 return gop - vif->tx_map_ops;
1334 /* Consolidate skb with a frag_list into a brand new one with local pages on
1335 * frags. Returns 0 or -ENOMEM if can't allocate new pages.
1337 static int xenvif_handle_frag_list(struct xenvif *vif, struct sk_buff *skb)
1339 unsigned int offset = skb_headlen(skb);
1340 skb_frag_t frags[MAX_SKB_FRAGS];
1342 struct ubuf_info *uarg;
1343 struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
1345 vif->tx_zerocopy_sent += 2;
1346 vif->tx_frag_overflow++;
1348 xenvif_fill_frags(vif, nskb);
1349 /* Subtract frags size, we will correct it later */
1350 skb->truesize -= skb->data_len;
1351 skb->len += nskb->len;
1352 skb->data_len += nskb->len;
1354 /* create a brand new frags array and coalesce there */
1355 for (i = 0; offset < skb->len; i++) {
1359 BUG_ON(i >= MAX_SKB_FRAGS);
1360 page = alloc_page(GFP_ATOMIC|__GFP_COLD);
1363 skb->truesize += skb->data_len;
1364 for (j = 0; j < i; j++)
1365 put_page(frags[j].page.p);
1369 if (offset + PAGE_SIZE < skb->len)
1372 len = skb->len - offset;
1373 if (skb_copy_bits(skb, offset, page_address(page), len))
1377 frags[i].page.p = page;
1378 frags[i].page_offset = 0;
1379 skb_frag_size_set(&frags[i], len);
1381 /* swap out with old one */
1382 memcpy(skb_shinfo(skb)->frags,
1384 i * sizeof(skb_frag_t));
1385 skb_shinfo(skb)->nr_frags = i;
1386 skb->truesize += i * PAGE_SIZE;
1388 /* remove traces of mapped pages and frag_list */
1389 skb_frag_list_init(skb);
1390 uarg = skb_shinfo(skb)->destructor_arg;
1391 uarg->callback(uarg, true);
1392 skb_shinfo(skb)->destructor_arg = NULL;
1394 skb_shinfo(nskb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1400 static int xenvif_tx_submit(struct xenvif *vif)
1402 struct gnttab_map_grant_ref *gop = vif->tx_map_ops;
1403 struct sk_buff *skb;
1406 while ((skb = __skb_dequeue(&vif->tx_queue)) != NULL) {
1407 struct xen_netif_tx_request *txp;
1411 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
1412 txp = &vif->pending_tx_info[pending_idx].req;
1414 /* Check the remap error code. */
1415 if (unlikely(xenvif_tx_check_gop(vif, skb, &gop))) {
1416 netdev_dbg(vif->dev, "netback grant failed.\n");
1417 skb_shinfo(skb)->nr_frags = 0;
1422 data_len = skb->len;
1424 (void *)(idx_to_kaddr(vif, pending_idx)|txp->offset),
1426 callback_param(vif, pending_idx).ctx = NULL;
1427 if (data_len < txp->size) {
1428 /* Append the packet payload as a fragment. */
1429 txp->offset += data_len;
1430 txp->size -= data_len;
1431 skb_shinfo(skb)->destructor_arg =
1432 &callback_param(vif, pending_idx);
1434 /* Schedule a response immediately. */
1435 xenvif_idx_unmap(vif, pending_idx);
1438 if (txp->flags & XEN_NETTXF_csum_blank)
1439 skb->ip_summed = CHECKSUM_PARTIAL;
1440 else if (txp->flags & XEN_NETTXF_data_validated)
1441 skb->ip_summed = CHECKSUM_UNNECESSARY;
1443 xenvif_fill_frags(vif, skb);
1445 if (unlikely(skb_has_frag_list(skb))) {
1446 if (xenvif_handle_frag_list(vif, skb)) {
1447 if (net_ratelimit())
1448 netdev_err(vif->dev,
1449 "Not enough memory to consolidate frag_list!\n");
1450 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1456 if (skb_is_nonlinear(skb) && skb_headlen(skb) < PKT_PROT_LEN) {
1457 int target = min_t(int, skb->len, PKT_PROT_LEN);
1458 __pskb_pull_tail(skb, target - skb_headlen(skb));
1461 skb->dev = vif->dev;
1462 skb->protocol = eth_type_trans(skb, skb->dev);
1463 skb_reset_network_header(skb);
1465 if (checksum_setup(vif, skb)) {
1466 netdev_dbg(vif->dev,
1467 "Can't setup checksum in net_tx_action\n");
1468 /* We have to set this flag to trigger the callback */
1469 if (skb_shinfo(skb)->destructor_arg)
1470 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1475 skb_probe_transport_header(skb, 0);
1477 /* If the packet is GSO then we will have just set up the
1478 * transport header offset in checksum_setup so it's now
1479 * straightforward to calculate gso_segs.
1481 if (skb_is_gso(skb)) {
1482 int mss = skb_shinfo(skb)->gso_size;
1483 int hdrlen = skb_transport_header(skb) -
1484 skb_mac_header(skb) +
1487 skb_shinfo(skb)->gso_segs =
1488 DIV_ROUND_UP(skb->len - hdrlen, mss);
1491 vif->dev->stats.rx_bytes += skb->len;
1492 vif->dev->stats.rx_packets++;
1496 /* Set this flag right before netif_receive_skb, otherwise
1497 * someone might think this packet already left netback, and
1498 * do a skb_copy_ubufs while we are still in control of the
1499 * skb. E.g. the __pskb_pull_tail earlier can do such thing.
1501 if (skb_shinfo(skb)->destructor_arg) {
1502 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
1503 vif->tx_zerocopy_sent++;
1506 netif_receive_skb(skb);
1512 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success)
1514 unsigned long flags;
1515 pending_ring_idx_t index;
1516 struct xenvif *vif = ubuf_to_vif(ubuf);
1518 /* This is the only place where we grab this lock, to protect callbacks
1521 spin_lock_irqsave(&vif->callback_lock, flags);
1523 u16 pending_idx = ubuf->desc;
1524 ubuf = (struct ubuf_info *) ubuf->ctx;
1525 BUG_ON(vif->dealloc_prod - vif->dealloc_cons >=
1527 index = pending_index(vif->dealloc_prod);
1528 vif->dealloc_ring[index] = pending_idx;
1529 /* Sync with xenvif_tx_dealloc_action:
1530 * insert idx then incr producer.
1533 vif->dealloc_prod++;
1535 wake_up(&vif->dealloc_wq);
1536 spin_unlock_irqrestore(&vif->callback_lock, flags);
1538 if (likely(zerocopy_success))
1539 vif->tx_zerocopy_success++;
1541 vif->tx_zerocopy_fail++;
1544 static inline void xenvif_tx_dealloc_action(struct xenvif *vif)
1546 struct gnttab_unmap_grant_ref *gop;
1547 pending_ring_idx_t dc, dp;
1548 u16 pending_idx, pending_idx_release[MAX_PENDING_REQS];
1551 dc = vif->dealloc_cons;
1552 gop = vif->tx_unmap_ops;
1554 /* Free up any grants we have finished using */
1556 dp = vif->dealloc_prod;
1558 /* Ensure we see all indices enqueued by all
1559 * xenvif_zerocopy_callback().
1564 BUG_ON(gop - vif->tx_unmap_ops > MAX_PENDING_REQS);
1566 vif->dealloc_ring[pending_index(dc++)];
1568 pending_idx_release[gop-vif->tx_unmap_ops] =
1570 vif->pages_to_unmap[gop-vif->tx_unmap_ops] =
1571 vif->mmap_pages[pending_idx];
1572 gnttab_set_unmap_op(gop,
1573 idx_to_kaddr(vif, pending_idx),
1575 vif->grant_tx_handle[pending_idx]);
1576 xenvif_grant_handle_reset(vif, pending_idx);
1580 } while (dp != vif->dealloc_prod);
1582 vif->dealloc_cons = dc;
1584 if (gop - vif->tx_unmap_ops > 0) {
1586 ret = gnttab_unmap_refs(vif->tx_unmap_ops,
1588 vif->pages_to_unmap,
1589 gop - vif->tx_unmap_ops);
1591 netdev_err(vif->dev, "Unmap fail: nr_ops %tx ret %d\n",
1592 gop - vif->tx_unmap_ops, ret);
1593 for (i = 0; i < gop - vif->tx_unmap_ops; ++i) {
1594 if (gop[i].status != GNTST_okay)
1595 netdev_err(vif->dev,
1596 " host_addr: %llx handle: %x status: %d\n",
1605 for (i = 0; i < gop - vif->tx_unmap_ops; ++i)
1606 xenvif_idx_release(vif, pending_idx_release[i],
1607 XEN_NETIF_RSP_OKAY);
1611 /* Called after netfront has transmitted */
1612 int xenvif_tx_action(struct xenvif *vif, int budget)
1617 if (unlikely(!tx_work_todo(vif)))
1620 nr_gops = xenvif_tx_build_gops(vif, budget);
1625 ret = gnttab_map_refs(vif->tx_map_ops,
1631 work_done = xenvif_tx_submit(vif);
1636 static void xenvif_idx_release(struct xenvif *vif, u16 pending_idx,
1639 struct pending_tx_info *pending_tx_info;
1640 pending_ring_idx_t index;
1641 unsigned long flags;
1643 pending_tx_info = &vif->pending_tx_info[pending_idx];
1644 spin_lock_irqsave(&vif->response_lock, flags);
1645 make_tx_response(vif, &pending_tx_info->req, status);
1646 index = pending_index(vif->pending_prod);
1647 vif->pending_ring[index] = pending_idx;
1648 /* TX shouldn't use the index before we give it back here */
1650 vif->pending_prod++;
1651 spin_unlock_irqrestore(&vif->response_lock, flags);
1655 static void make_tx_response(struct xenvif *vif,
1656 struct xen_netif_tx_request *txp,
1659 RING_IDX i = vif->tx.rsp_prod_pvt;
1660 struct xen_netif_tx_response *resp;
1663 resp = RING_GET_RESPONSE(&vif->tx, i);
1667 if (txp->flags & XEN_NETTXF_extra_info)
1668 RING_GET_RESPONSE(&vif->tx, ++i)->status = XEN_NETIF_RSP_NULL;
1670 vif->tx.rsp_prod_pvt = ++i;
1671 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->tx, notify);
1673 notify_remote_via_irq(vif->tx_irq);
1676 static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif,
1683 RING_IDX i = vif->rx.rsp_prod_pvt;
1684 struct xen_netif_rx_response *resp;
1686 resp = RING_GET_RESPONSE(&vif->rx, i);
1687 resp->offset = offset;
1688 resp->flags = flags;
1690 resp->status = (s16)size;
1692 resp->status = (s16)st;
1694 vif->rx.rsp_prod_pvt = ++i;
1699 void xenvif_idx_unmap(struct xenvif *vif, u16 pending_idx)
1702 struct gnttab_unmap_grant_ref tx_unmap_op;
1704 gnttab_set_unmap_op(&tx_unmap_op,
1705 idx_to_kaddr(vif, pending_idx),
1707 vif->grant_tx_handle[pending_idx]);
1708 xenvif_grant_handle_reset(vif, pending_idx);
1710 ret = gnttab_unmap_refs(&tx_unmap_op, NULL,
1711 &vif->mmap_pages[pending_idx], 1);
1713 netdev_err(vif->dev,
1714 "Unmap fail: ret: %d pending_idx: %d host_addr: %llx handle: %x status: %d\n",
1717 tx_unmap_op.host_addr,
1719 tx_unmap_op.status);
1723 xenvif_idx_release(vif, pending_idx, XEN_NETIF_RSP_OKAY);
1726 static inline int rx_work_todo(struct xenvif *vif)
1728 return (!skb_queue_empty(&vif->rx_queue) &&
1729 xenvif_rx_ring_slots_available(vif, vif->rx_last_skb_slots)) ||
1730 vif->rx_queue_purge;
1733 static inline int tx_work_todo(struct xenvif *vif)
1736 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->tx)))
1742 static inline bool tx_dealloc_work_todo(struct xenvif *vif)
1744 return vif->dealloc_cons != vif->dealloc_prod;
1747 void xenvif_unmap_frontend_rings(struct xenvif *vif)
1750 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
1753 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
1757 int xenvif_map_frontend_rings(struct xenvif *vif,
1758 grant_ref_t tx_ring_ref,
1759 grant_ref_t rx_ring_ref)
1762 struct xen_netif_tx_sring *txs;
1763 struct xen_netif_rx_sring *rxs;
1767 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
1768 tx_ring_ref, &addr);
1772 txs = (struct xen_netif_tx_sring *)addr;
1773 BACK_RING_INIT(&vif->tx, txs, PAGE_SIZE);
1775 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
1776 rx_ring_ref, &addr);
1780 rxs = (struct xen_netif_rx_sring *)addr;
1781 BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE);
1786 xenvif_unmap_frontend_rings(vif);
1790 void xenvif_stop_queue(struct xenvif *vif)
1792 if (!vif->can_queue)
1795 netif_stop_queue(vif->dev);
1798 static void xenvif_start_queue(struct xenvif *vif)
1800 if (xenvif_schedulable(vif))
1801 netif_wake_queue(vif->dev);
1804 int xenvif_kthread_guest_rx(void *data)
1806 struct xenvif *vif = data;
1807 struct sk_buff *skb;
1809 while (!kthread_should_stop()) {
1810 wait_event_interruptible(vif->wq,
1811 rx_work_todo(vif) ||
1813 kthread_should_stop());
1815 /* This frontend is found to be rogue, disable it in
1816 * kthread context. Currently this is only set when
1817 * netback finds out frontend sends malformed packet,
1818 * but we cannot disable the interface in softirq
1819 * context so we defer it here.
1821 if (unlikely(vif->disabled && netif_carrier_ok(vif->dev)))
1822 xenvif_carrier_off(vif);
1824 if (kthread_should_stop())
1827 if (vif->rx_queue_purge) {
1828 skb_queue_purge(&vif->rx_queue);
1829 vif->rx_queue_purge = false;
1832 if (!skb_queue_empty(&vif->rx_queue))
1833 xenvif_rx_action(vif);
1835 if (skb_queue_empty(&vif->rx_queue) &&
1836 netif_queue_stopped(vif->dev)) {
1837 del_timer_sync(&vif->wake_queue);
1838 xenvif_start_queue(vif);
1844 /* Bin any remaining skbs */
1845 while ((skb = skb_dequeue(&vif->rx_queue)) != NULL)
1851 int xenvif_dealloc_kthread(void *data)
1853 struct xenvif *vif = data;
1855 while (!kthread_should_stop()) {
1856 wait_event_interruptible(vif->dealloc_wq,
1857 tx_dealloc_work_todo(vif) ||
1858 kthread_should_stop());
1859 if (kthread_should_stop())
1862 xenvif_tx_dealloc_action(vif);
1866 /* Unmap anything remaining*/
1867 if (tx_dealloc_work_todo(vif))
1868 xenvif_tx_dealloc_action(vif);
1873 static int __init netback_init(void)
1880 if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
1881 pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
1882 fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX);
1883 fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX;
1886 rc = xenvif_xenbus_init();
1890 rx_drain_timeout_jiffies = msecs_to_jiffies(rx_drain_timeout_msecs);
1898 module_init(netback_init);
1900 static void __exit netback_fini(void)
1902 xenvif_xenbus_fini();
1904 module_exit(netback_fini);
1906 MODULE_LICENSE("Dual BSD/GPL");
1907 MODULE_ALIAS("xen-backend:vif");