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Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[cris-mirror.git] / drivers / net / xen-netback / netback.c
blobedbae0b1e8f0ed8e9be929767c01cecf838fa5fd
1 /*
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
7 *
8 * Copyright (c) 2002-2005, K A Fraser
9 *
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:
15 *
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:
22 *
23 * The above copyright notice and this permission notice shall be included in
24 * all copies or substantial portions of the Software.
25 *
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
32 * IN THE SOFTWARE.
33 */
34
35 #include "common.h"
36
37 #include <linux/kthread.h>
38 #include <linux/if_vlan.h>
39 #include <linux/udp.h>
40 #include <linux/highmem.h>
41
42 #include <net/tcp.h>
43
44 #include <xen/xen.h>
45 #include <xen/events.h>
46 #include <xen/interface/memory.h>
47 #include <xen/page.h>
48
49 #include <asm/xen/hypercall.h>
50
51 /* Provide an option to disable split event channels at load time as
52 * event channels are limited resource. Split event channels are
53 * enabled by default.
54 */
55 bool separate_tx_rx_irq = true;
56 module_param(separate_tx_rx_irq, bool, 0644);
57
58 /* The time that packets can stay on the guest Rx internal queue
59 * before they are dropped.
60 */
61 unsigned int rx_drain_timeout_msecs = 10000;
62 module_param(rx_drain_timeout_msecs, uint, 0444);
63
64 /* The length of time before the frontend is considered unresponsive
65 * because it isn't providing Rx slots.
66 */
67 unsigned int rx_stall_timeout_msecs = 60000;
68 module_param(rx_stall_timeout_msecs, uint, 0444);
69
70 unsigned int xenvif_max_queues;
71 module_param_named(max_queues, xenvif_max_queues, uint, 0644);
72 MODULE_PARM_DESC(max_queues,
73 "Maximum number of queues per virtual interface");
74
75 /*
76 * This is the maximum slots a skb can have. If a guest sends a skb
77 * which exceeds this limit it is considered malicious.
78 */
79 #define FATAL_SKB_SLOTS_DEFAULT 20
80 static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT;
81 module_param(fatal_skb_slots, uint, 0444);
82
83 /* The amount to copy out of the first guest Tx slot into the skb's
84 * linear area. If the first slot has more data, it will be mapped
85 * and put into the first frag.
86 *
87 * This is sized to avoid pulling headers from the frags for most
88 * TCP/IP packets.
89 */
90 #define XEN_NETBACK_TX_COPY_LEN 128
91
92 /* This is the maximum number of flows in the hash cache. */
93 #define XENVIF_HASH_CACHE_SIZE_DEFAULT 64
94 unsigned int xenvif_hash_cache_size = XENVIF_HASH_CACHE_SIZE_DEFAULT;
95 module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, 0644);
96 MODULE_PARM_DESC(hash_cache_size, "Number of flows in the hash cache");
97
98 static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
99 u8 status);
100
101 static void make_tx_response(struct xenvif_queue *queue,
102 struct xen_netif_tx_request *txp,
103 unsigned int extra_count,
104 s8 st);
105 static void push_tx_responses(struct xenvif_queue *queue);
106
107 static inline int tx_work_todo(struct xenvif_queue *queue);
108
109 static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue,
110 u16 id,
111 s8 st,
112 u16 offset,
113 u16 size,
114 u16 flags);
115
116 static inline unsigned long idx_to_pfn(struct xenvif_queue *queue,
117 u16 idx)
118 {
119 return page_to_pfn(queue->mmap_pages[idx]);
120 }
121
122 static inline unsigned long idx_to_kaddr(struct xenvif_queue *queue,
123 u16 idx)
124 {
125 return (unsigned long)pfn_to_kaddr(idx_to_pfn(queue, idx));
126 }
127
128 #define callback_param(vif, pending_idx) \
129 (vif->pending_tx_info[pending_idx].callback_struct)
130
131 /* Find the containing VIF's structure from a pointer in pending_tx_info array
132 */
133 static inline struct xenvif_queue *ubuf_to_queue(const struct ubuf_info *ubuf)
134 {
135 u16 pending_idx = ubuf->desc;
136 struct pending_tx_info *temp =
137 container_of(ubuf, struct pending_tx_info, callback_struct);
138 return container_of(temp - pending_idx,
139 struct xenvif_queue,
140 pending_tx_info[0]);
141 }
142
143 static u16 frag_get_pending_idx(skb_frag_t *frag)
144 {
145 return (u16)frag->page_offset;
146 }
147
148 static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx)
149 {
150 frag->page_offset = pending_idx;
151 }
152
153 static inline pending_ring_idx_t pending_index(unsigned i)
154 {
155 return i & (MAX_PENDING_REQS-1);
156 }
157
158 static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue)
159 {
160 RING_IDX prod, cons;
161 struct sk_buff *skb;
162 int needed;
163
164 skb = skb_peek(&queue->rx_queue);
165 if (!skb)
166 return false;
167
168 needed = DIV_ROUND_UP(skb->len, XEN_PAGE_SIZE);
169 if (skb_is_gso(skb))
170 needed++;
171 if (skb->sw_hash)
172 needed++;
173
174 do {
175 prod = queue->rx.sring->req_prod;
176 cons = queue->rx.req_cons;
177
178 if (prod - cons >= needed)
179 return true;
180
181 queue->rx.sring->req_event = prod + 1;
182
183 /* Make sure event is visible before we check prod
184 * again.
185 */
186 mb();
187 } while (queue->rx.sring->req_prod != prod);
188
189 return false;
190 }
191
192 void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb)
193 {
194 unsigned long flags;
195
196 spin_lock_irqsave(&queue->rx_queue.lock, flags);
197
198 __skb_queue_tail(&queue->rx_queue, skb);
199
200 queue->rx_queue_len += skb->len;
201 if (queue->rx_queue_len > queue->rx_queue_max)
202 netif_tx_stop_queue(netdev_get_tx_queue(queue->vif->dev, queue->id));
203
204 spin_unlock_irqrestore(&queue->rx_queue.lock, flags);
205 }
206
207 static struct sk_buff *xenvif_rx_dequeue(struct xenvif_queue *queue)
208 {
209 struct sk_buff *skb;
210
211 spin_lock_irq(&queue->rx_queue.lock);
212
213 skb = __skb_dequeue(&queue->rx_queue);
214 if (skb)
215 queue->rx_queue_len -= skb->len;
216
217 spin_unlock_irq(&queue->rx_queue.lock);
218
219 return skb;
220 }
221
222 static void xenvif_rx_queue_maybe_wake(struct xenvif_queue *queue)
223 {
224 spin_lock_irq(&queue->rx_queue.lock);
225
226 if (queue->rx_queue_len < queue->rx_queue_max)
227 netif_tx_wake_queue(netdev_get_tx_queue(queue->vif->dev, queue->id));
228
229 spin_unlock_irq(&queue->rx_queue.lock);
230 }
231
232
233 static void xenvif_rx_queue_purge(struct xenvif_queue *queue)
234 {
235 struct sk_buff *skb;
236 while ((skb = xenvif_rx_dequeue(queue)) != NULL)
237 kfree_skb(skb);
238 }
239
240 static void xenvif_rx_queue_drop_expired(struct xenvif_queue *queue)
241 {
242 struct sk_buff *skb;
243
244 for(;;) {
245 skb = skb_peek(&queue->rx_queue);
246 if (!skb)
247 break;
248 if (time_before(jiffies, XENVIF_RX_CB(skb)->expires))
249 break;
250 xenvif_rx_dequeue(queue);
251 kfree_skb(skb);
252 }
253 }
254
255 struct netrx_pending_operations {
256 unsigned copy_prod, copy_cons;
257 unsigned meta_prod, meta_cons;
258 struct gnttab_copy *copy;
259 struct xenvif_rx_meta *meta;
260 int copy_off;
261 grant_ref_t copy_gref;
262 };
263
264 static struct xenvif_rx_meta *get_next_rx_buffer(struct xenvif_queue *queue,
265 struct netrx_pending_operations *npo)
266 {
267 struct xenvif_rx_meta *meta;
268 struct xen_netif_rx_request req;
269
270 RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
271
272 meta = npo->meta + npo->meta_prod++;
273 meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
274 meta->gso_size = 0;
275 meta->size = 0;
276 meta->id = req.id;
277
278 npo->copy_off = 0;
279 npo->copy_gref = req.gref;
280
281 return meta;
282 }
283
284 struct gop_frag_copy {
285 struct xenvif_queue *queue;
286 struct netrx_pending_operations *npo;
287 struct xenvif_rx_meta *meta;
288 int head;
289 int gso_type;
290 int protocol;
291 int hash_present;
292
293 struct page *page;
294 };
295
296 static void xenvif_setup_copy_gop(unsigned long gfn,
297 unsigned int offset,
298 unsigned int *len,
299 struct gop_frag_copy *info)
300 {
301 struct gnttab_copy *copy_gop;
302 struct xen_page_foreign *foreign;
303 /* Convenient aliases */
304 struct xenvif_queue *queue = info->queue;
305 struct netrx_pending_operations *npo = info->npo;
306 struct page *page = info->page;
307
308 BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET);
309
310 if (npo->copy_off == MAX_BUFFER_OFFSET)
311 info->meta = get_next_rx_buffer(queue, npo);
312
313 if (npo->copy_off + *len > MAX_BUFFER_OFFSET)
314 *len = MAX_BUFFER_OFFSET - npo->copy_off;
315
316 copy_gop = npo->copy + npo->copy_prod++;
317 copy_gop->flags = GNTCOPY_dest_gref;
318 copy_gop->len = *len;
319
320 foreign = xen_page_foreign(page);
321 if (foreign) {
322 copy_gop->source.domid = foreign->domid;
323 copy_gop->source.u.ref = foreign->gref;
324 copy_gop->flags |= GNTCOPY_source_gref;
325 } else {
326 copy_gop->source.domid = DOMID_SELF;
327 copy_gop->source.u.gmfn = gfn;
328 }
329 copy_gop->source.offset = offset;
330
331 copy_gop->dest.domid = queue->vif->domid;
332 copy_gop->dest.offset = npo->copy_off;
333 copy_gop->dest.u.ref = npo->copy_gref;
334
335 npo->copy_off += *len;
336 info->meta->size += *len;
337
338 if (!info->head)
339 return;
340
341 /* Leave a gap for the GSO descriptor. */
342 if ((1 << info->gso_type) & queue->vif->gso_mask)
343 queue->rx.req_cons++;
344
345 /* Leave a gap for the hash extra segment. */
346 if (info->hash_present)
347 queue->rx.req_cons++;
348
349 info->head = 0; /* There must be something in this buffer now */
350 }
351
352 static void xenvif_gop_frag_copy_grant(unsigned long gfn,
353 unsigned offset,
354 unsigned int len,
355 void *data)
356 {
357 unsigned int bytes;
358
359 while (len) {
360 bytes = len;
361 xenvif_setup_copy_gop(gfn, offset, &bytes, data);
362 offset += bytes;
363 len -= bytes;
364 }
365 }
366
367 /*
368 * Set up the grant operations for this fragment. If it's a flipping
369 * interface, we also set up the unmap request from here.
370 */
371 static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb,
372 struct netrx_pending_operations *npo,
373 struct page *page, unsigned long size,
374 unsigned long offset, int *head)
375 {
376 struct gop_frag_copy info = {
377 .queue = queue,
378 .npo = npo,
379 .head = *head,
380 .gso_type = XEN_NETIF_GSO_TYPE_NONE,
381 /* xenvif_set_skb_hash() will have either set a s/w
382 * hash or cleared the hash depending on
383 * whether the the frontend wants a hash for this skb.
384 */
385 .hash_present = skb->sw_hash,
386 };
387 unsigned long bytes;
388
389 if (skb_is_gso(skb)) {
390 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
391 info.gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
392 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
393 info.gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
394 }
395
396 /* Data must not cross a page boundary. */
397 BUG_ON(size + offset > PAGE_SIZE<<compound_order(page));
398
399 info.meta = npo->meta + npo->meta_prod - 1;
400
401 /* Skip unused frames from start of page */
402 page += offset >> PAGE_SHIFT;
403 offset &= ~PAGE_MASK;
404
405 while (size > 0) {
406 BUG_ON(offset >= PAGE_SIZE);
407
408 bytes = PAGE_SIZE - offset;
409 if (bytes > size)
410 bytes = size;
411
412 info.page = page;
413 gnttab_foreach_grant_in_range(page, offset, bytes,
414 xenvif_gop_frag_copy_grant,
415 &info);
416 size -= bytes;
417 offset = 0;
418
419 /* Next page */
420 if (size) {
421 BUG_ON(!PageCompound(page));
422 page++;
423 }
424 }
425
426 *head = info.head;
427 }
428
429 /*
430 * Prepare an SKB to be transmitted to the frontend.
431 *
432 * This function is responsible for allocating grant operations, meta
433 * structures, etc.
434 *
435 * It returns the number of meta structures consumed. The number of
436 * ring slots used is always equal to the number of meta slots used
437 * plus the number of GSO descriptors used. Currently, we use either
438 * zero GSO descriptors (for non-GSO packets) or one descriptor (for
439 * frontend-side LRO).
440 */
441 static int xenvif_gop_skb(struct sk_buff *skb,
442 struct netrx_pending_operations *npo,
443 struct xenvif_queue *queue)
444 {
445 struct xenvif *vif = netdev_priv(skb->dev);
446 int nr_frags = skb_shinfo(skb)->nr_frags;
447 int i;
448 struct xen_netif_rx_request req;
449 struct xenvif_rx_meta *meta;
450 unsigned char *data;
451 int head = 1;
452 int old_meta_prod;
453 int gso_type;
454
455 old_meta_prod = npo->meta_prod;
456
457 gso_type = XEN_NETIF_GSO_TYPE_NONE;
458 if (skb_is_gso(skb)) {
459 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
460 gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
461 else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
462 gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
463 }
464
465 /* Set up a GSO prefix descriptor, if necessary */
466 if ((1 << gso_type) & vif->gso_prefix_mask) {
467 RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
468 meta = npo->meta + npo->meta_prod++;
469 meta->gso_type = gso_type;
470 meta->gso_size = skb_shinfo(skb)->gso_size;
471 meta->size = 0;
472 meta->id = req.id;
473 }
474
475 RING_COPY_REQUEST(&queue->rx, queue->rx.req_cons++, &req);
476 meta = npo->meta + npo->meta_prod++;
477
478 if ((1 << gso_type) & vif->gso_mask) {
479 meta->gso_type = gso_type;
480 meta->gso_size = skb_shinfo(skb)->gso_size;
481 } else {
482 meta->gso_type = XEN_NETIF_GSO_TYPE_NONE;
483 meta->gso_size = 0;
484 }
485
486 meta->size = 0;
487 meta->id = req.id;
488 npo->copy_off = 0;
489 npo->copy_gref = req.gref;
490
491 data = skb->data;
492 while (data < skb_tail_pointer(skb)) {
493 unsigned int offset = offset_in_page(data);
494 unsigned int len = PAGE_SIZE - offset;
495
496 if (data + len > skb_tail_pointer(skb))
497 len = skb_tail_pointer(skb) - data;
498
499 xenvif_gop_frag_copy(queue, skb, npo,
500 virt_to_page(data), len, offset, &head);
501 data += len;
502 }
503
504 for (i = 0; i < nr_frags; i++) {
505 xenvif_gop_frag_copy(queue, skb, npo,
506 skb_frag_page(&skb_shinfo(skb)->frags[i]),
507 skb_frag_size(&skb_shinfo(skb)->frags[i]),
508 skb_shinfo(skb)->frags[i].page_offset,
509 &head);
510 }
511
512 return npo->meta_prod - old_meta_prod;
513 }
514
515 /*
516 * This is a twin to xenvif_gop_skb. Assume that xenvif_gop_skb was
517 * used to set up the operations on the top of
518 * netrx_pending_operations, which have since been done. Check that
519 * they didn't give any errors and advance over them.
520 */
521 static int xenvif_check_gop(struct xenvif *vif, int nr_meta_slots,
522 struct netrx_pending_operations *npo)
523 {
524 struct gnttab_copy *copy_op;
525 int status = XEN_NETIF_RSP_OKAY;
526 int i;
527
528 for (i = 0; i < nr_meta_slots; i++) {
529 copy_op = npo->copy + npo->copy_cons++;
530 if (copy_op->status != GNTST_okay) {
531 netdev_dbg(vif->dev,
532 "Bad status %d from copy to DOM%d.\n",
533 copy_op->status, vif->domid);
534 status = XEN_NETIF_RSP_ERROR;
535 }
536 }
537
538 return status;
539 }
540
541 static void xenvif_add_frag_responses(struct xenvif_queue *queue, int status,
542 struct xenvif_rx_meta *meta,
543 int nr_meta_slots)
544 {
545 int i;
546 unsigned long offset;
547
548 /* No fragments used */
549 if (nr_meta_slots <= 1)
550 return;
551
552 nr_meta_slots--;
553
554 for (i = 0; i < nr_meta_slots; i++) {
555 int flags;
556 if (i == nr_meta_slots - 1)
557 flags = 0;
558 else
559 flags = XEN_NETRXF_more_data;
560
561 offset = 0;
562 make_rx_response(queue, meta[i].id, status, offset,
563 meta[i].size, flags);
564 }
565 }
566
567 void xenvif_kick_thread(struct xenvif_queue *queue)
568 {
569 wake_up(&queue->wq);
570 }
571
572 static void xenvif_rx_action(struct xenvif_queue *queue)
573 {
574 struct xenvif *vif = queue->vif;
575 s8 status;
576 u16 flags;
577 struct xen_netif_rx_response *resp;
578 struct sk_buff_head rxq;
579 struct sk_buff *skb;
580 LIST_HEAD(notify);
581 int ret;
582 unsigned long offset;
583 bool need_to_notify = false;
584
585 struct netrx_pending_operations npo = {
586 .copy = queue->grant_copy_op,
587 .meta = queue->meta,
588 };
589
590 skb_queue_head_init(&rxq);
591
592 while (xenvif_rx_ring_slots_available(queue)
593 && (skb = xenvif_rx_dequeue(queue)) != NULL) {
594 queue->last_rx_time = jiffies;
595
596 XENVIF_RX_CB(skb)->meta_slots_used = xenvif_gop_skb(skb, &npo, queue);
597
598 __skb_queue_tail(&rxq, skb);
599 }
600
601 BUG_ON(npo.meta_prod > ARRAY_SIZE(queue->meta));
602
603 if (!npo.copy_prod)
604 goto done;
605
606 BUG_ON(npo.copy_prod > MAX_GRANT_COPY_OPS);
607 gnttab_batch_copy(queue->grant_copy_op, npo.copy_prod);
608
609 while ((skb = __skb_dequeue(&rxq)) != NULL) {
610 struct xen_netif_extra_info *extra = NULL;
611
612 if ((1 << queue->meta[npo.meta_cons].gso_type) &
613 vif->gso_prefix_mask) {
614 resp = RING_GET_RESPONSE(&queue->rx,
615 queue->rx.rsp_prod_pvt++);
616
617 resp->flags = XEN_NETRXF_gso_prefix | XEN_NETRXF_more_data;
618
619 resp->offset = queue->meta[npo.meta_cons].gso_size;
620 resp->id = queue->meta[npo.meta_cons].id;
621 resp->status = XENVIF_RX_CB(skb)->meta_slots_used;
622
623 npo.meta_cons++;
624 XENVIF_RX_CB(skb)->meta_slots_used--;
625 }
626
627
628 queue->stats.tx_bytes += skb->len;
629 queue->stats.tx_packets++;
630
631 status = xenvif_check_gop(vif,
632 XENVIF_RX_CB(skb)->meta_slots_used,
633 &npo);
634
635 if (XENVIF_RX_CB(skb)->meta_slots_used == 1)
636 flags = 0;
637 else
638 flags = XEN_NETRXF_more_data;
639
640 if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */
641 flags |= XEN_NETRXF_csum_blank | XEN_NETRXF_data_validated;
642 else if (skb->ip_summed == CHECKSUM_UNNECESSARY)
643 /* remote but checksummed. */
644 flags |= XEN_NETRXF_data_validated;
645
646 offset = 0;
647 resp = make_rx_response(queue, queue->meta[npo.meta_cons].id,
648 status, offset,
649 queue->meta[npo.meta_cons].size,
650 flags);
651
652 if ((1 << queue->meta[npo.meta_cons].gso_type) &
653 vif->gso_mask) {
654 extra = (struct xen_netif_extra_info *)
655 RING_GET_RESPONSE(&queue->rx,
656 queue->rx.rsp_prod_pvt++);
657
658 resp->flags |= XEN_NETRXF_extra_info;
659
660 extra->u.gso.type = queue->meta[npo.meta_cons].gso_type;
661 extra->u.gso.size = queue->meta[npo.meta_cons].gso_size;
662 extra->u.gso.pad = 0;
663 extra->u.gso.features = 0;
664
665 extra->type = XEN_NETIF_EXTRA_TYPE_GSO;
666 extra->flags = 0;
667 }
668
669 if (skb->sw_hash) {
670 /* Since the skb got here via xenvif_select_queue()
671 * we know that the hash has been re-calculated
672 * according to a configuration set by the frontend
673 * and therefore we know that it is legitimate to
674 * pass it to the frontend.
675 */
676 if (resp->flags & XEN_NETRXF_extra_info)
677 extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;
678 else
679 resp->flags |= XEN_NETRXF_extra_info;
680
681 extra = (struct xen_netif_extra_info *)
682 RING_GET_RESPONSE(&queue->rx,
683 queue->rx.rsp_prod_pvt++);
684
685 extra->u.hash.algorithm =
686 XEN_NETIF_CTRL_HASH_ALGORITHM_TOEPLITZ;
687
688 if (skb->l4_hash)
689 extra->u.hash.type =
690 skb->protocol == htons(ETH_P_IP) ?
691 _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP :
692 _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP;
693 else
694 extra->u.hash.type =
695 skb->protocol == htons(ETH_P_IP) ?
696 _XEN_NETIF_CTRL_HASH_TYPE_IPV4 :
697 _XEN_NETIF_CTRL_HASH_TYPE_IPV6;
698
699 *(uint32_t *)extra->u.hash.value =
700 skb_get_hash_raw(skb);
701
702 extra->type = XEN_NETIF_EXTRA_TYPE_HASH;
703 extra->flags = 0;
704 }
705
706 xenvif_add_frag_responses(queue, status,
707 queue->meta + npo.meta_cons + 1,
708 XENVIF_RX_CB(skb)->meta_slots_used);
709
710 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->rx, ret);
711
712 need_to_notify |= !!ret;
713
714 npo.meta_cons += XENVIF_RX_CB(skb)->meta_slots_used;
715 dev_kfree_skb(skb);
716 }
717
718 done:
719 if (need_to_notify)
720 notify_remote_via_irq(queue->rx_irq);
721 }
722
723 void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue)
724 {
725 int more_to_do;
726
727 RING_FINAL_CHECK_FOR_REQUESTS(&queue->tx, more_to_do);
728
729 if (more_to_do)
730 napi_schedule(&queue->napi);
731 }
732
733 static void tx_add_credit(struct xenvif_queue *queue)
734 {
735 unsigned long max_burst, max_credit;
736
737 /*
738 * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
739 * Otherwise the interface can seize up due to insufficient credit.
740 */
741 max_burst = max(131072UL, queue->credit_bytes);
742
743 /* Take care that adding a new chunk of credit doesn't wrap to zero. */
744 max_credit = queue->remaining_credit + queue->credit_bytes;
745 if (max_credit < queue->remaining_credit)
746 max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
747
748 queue->remaining_credit = min(max_credit, max_burst);
749 }
750
751 void xenvif_tx_credit_callback(unsigned long data)
752 {
753 struct xenvif_queue *queue = (struct xenvif_queue *)data;
754 tx_add_credit(queue);
755 xenvif_napi_schedule_or_enable_events(queue);
756 }
757
758 static void xenvif_tx_err(struct xenvif_queue *queue,
759 struct xen_netif_tx_request *txp,
760 unsigned int extra_count, RING_IDX end)
761 {
762 RING_IDX cons = queue->tx.req_cons;
763 unsigned long flags;
764
765 do {
766 spin_lock_irqsave(&queue->response_lock, flags);
767 make_tx_response(queue, txp, extra_count, XEN_NETIF_RSP_ERROR);
768 push_tx_responses(queue);
769 spin_unlock_irqrestore(&queue->response_lock, flags);
770 if (cons == end)
771 break;
772 RING_COPY_REQUEST(&queue->tx, cons++, txp);
773 extra_count = 0; /* only the first frag can have extras */
774 } while (1);
775 queue->tx.req_cons = cons;
776 }
777
778 static void xenvif_fatal_tx_err(struct xenvif *vif)
779 {
780 netdev_err(vif->dev, "fatal error; disabling device\n");
781 vif->disabled = true;
782 /* Disable the vif from queue 0's kthread */
783 if (vif->queues)
784 xenvif_kick_thread(&vif->queues[0]);
785 }
786
787 static int xenvif_count_requests(struct xenvif_queue *queue,
788 struct xen_netif_tx_request *first,
789 unsigned int extra_count,
790 struct xen_netif_tx_request *txp,
791 int work_to_do)
792 {
793 RING_IDX cons = queue->tx.req_cons;
794 int slots = 0;
795 int drop_err = 0;
796 int more_data;
797
798 if (!(first->flags & XEN_NETTXF_more_data))
799 return 0;
800
801 do {
802 struct xen_netif_tx_request dropped_tx = { 0 };
803
804 if (slots >= work_to_do) {
805 netdev_err(queue->vif->dev,
806 "Asked for %d slots but exceeds this limit\n",
807 work_to_do);
808 xenvif_fatal_tx_err(queue->vif);
809 return -ENODATA;
810 }
811
812 /* This guest is really using too many slots and
813 * considered malicious.
814 */
815 if (unlikely(slots >= fatal_skb_slots)) {
816 netdev_err(queue->vif->dev,
817 "Malicious frontend using %d slots, threshold %u\n",
818 slots, fatal_skb_slots);
819 xenvif_fatal_tx_err(queue->vif);
820 return -E2BIG;
821 }
822
823 /* Xen network protocol had implicit dependency on
824 * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to
825 * the historical MAX_SKB_FRAGS value 18 to honor the
826 * same behavior as before. Any packet using more than
827 * 18 slots but less than fatal_skb_slots slots is
828 * dropped
829 */
830 if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) {
831 if (net_ratelimit())
832 netdev_dbg(queue->vif->dev,
833 "Too many slots (%d) exceeding limit (%d), dropping packet\n",
834 slots, XEN_NETBK_LEGACY_SLOTS_MAX);
835 drop_err = -E2BIG;
836 }
837
838 if (drop_err)
839 txp = &dropped_tx;
840
841 RING_COPY_REQUEST(&queue->tx, cons + slots, txp);
842
843 /* If the guest submitted a frame >= 64 KiB then
844 * first->size overflowed and following slots will
845 * appear to be larger than the frame.
846 *
847 * This cannot be fatal error as there are buggy
848 * frontends that do this.
849 *
850 * Consume all slots and drop the packet.
851 */
852 if (!drop_err && txp->size > first->size) {
853 if (net_ratelimit())
854 netdev_dbg(queue->vif->dev,
855 "Invalid tx request, slot size %u > remaining size %u\n",
856 txp->size, first->size);
857 drop_err = -EIO;
858 }
859
860 first->size -= txp->size;
861 slots++;
862
863 if (unlikely((txp->offset + txp->size) > XEN_PAGE_SIZE)) {
864 netdev_err(queue->vif->dev, "Cross page boundary, txp->offset: %u, size: %u\n",
865 txp->offset, txp->size);
866 xenvif_fatal_tx_err(queue->vif);
867 return -EINVAL;
868 }
869
870 more_data = txp->flags & XEN_NETTXF_more_data;
871
872 if (!drop_err)
873 txp++;
874
875 } while (more_data);
876
877 if (drop_err) {
878 xenvif_tx_err(queue, first, extra_count, cons + slots);
879 return drop_err;
880 }
881
882 return slots;
883 }
884
885
886 struct xenvif_tx_cb {
887 u16 pending_idx;
888 };
889
890 #define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb)
891
892 static inline void xenvif_tx_create_map_op(struct xenvif_queue *queue,
893 u16 pending_idx,
894 struct xen_netif_tx_request *txp,
895 unsigned int extra_count,
896 struct gnttab_map_grant_ref *mop)
897 {
898 queue->pages_to_map[mop-queue->tx_map_ops] = queue->mmap_pages[pending_idx];
899 gnttab_set_map_op(mop, idx_to_kaddr(queue, pending_idx),
900 GNTMAP_host_map | GNTMAP_readonly,
901 txp->gref, queue->vif->domid);
902
903 memcpy(&queue->pending_tx_info[pending_idx].req, txp,
904 sizeof(*txp));
905 queue->pending_tx_info[pending_idx].extra_count = extra_count;
906 }
907
908 static inline struct sk_buff *xenvif_alloc_skb(unsigned int size)
909 {
910 struct sk_buff *skb =
911 alloc_skb(size + NET_SKB_PAD + NET_IP_ALIGN,
912 GFP_ATOMIC | __GFP_NOWARN);
913 if (unlikely(skb == NULL))
914 return NULL;
915
916 /* Packets passed to netif_rx() must have some headroom. */
917 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
918
919 /* Initialize it here to avoid later surprises */
920 skb_shinfo(skb)->destructor_arg = NULL;
921
922 return skb;
923 }
924
925 static struct gnttab_map_grant_ref *xenvif_get_requests(struct xenvif_queue *queue,
926 struct sk_buff *skb,
927 struct xen_netif_tx_request *txp,
928 struct gnttab_map_grant_ref *gop,
929 unsigned int frag_overflow,
930 struct sk_buff *nskb)
931 {
932 struct skb_shared_info *shinfo = skb_shinfo(skb);
933 skb_frag_t *frags = shinfo->frags;
934 u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
935 int start;
936 pending_ring_idx_t index;
937 unsigned int nr_slots;
938
939 nr_slots = shinfo->nr_frags;
940
941 /* Skip first skb fragment if it is on same page as header fragment. */
942 start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
943
944 for (shinfo->nr_frags = start; shinfo->nr_frags < nr_slots;
945 shinfo->nr_frags++, txp++, gop++) {
946 index = pending_index(queue->pending_cons++);
947 pending_idx = queue->pending_ring[index];
948 xenvif_tx_create_map_op(queue, pending_idx, txp, 0, gop);
949 frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx);
950 }
951
952 if (frag_overflow) {
953
954 shinfo = skb_shinfo(nskb);
955 frags = shinfo->frags;
956
957 for (shinfo->nr_frags = 0; shinfo->nr_frags < frag_overflow;
958 shinfo->nr_frags++, txp++, gop++) {
959 index = pending_index(queue->pending_cons++);
960 pending_idx = queue->pending_ring[index];
961 xenvif_tx_create_map_op(queue, pending_idx, txp, 0,
962 gop);
963 frag_set_pending_idx(&frags[shinfo->nr_frags],
964 pending_idx);
965 }
966
967 skb_shinfo(skb)->frag_list = nskb;
968 }
969
970 return gop;
971 }
972
973 static inline void xenvif_grant_handle_set(struct xenvif_queue *queue,
974 u16 pending_idx,
975 grant_handle_t handle)
976 {
977 if (unlikely(queue->grant_tx_handle[pending_idx] !=
978 NETBACK_INVALID_HANDLE)) {
979 netdev_err(queue->vif->dev,
980 "Trying to overwrite active handle! pending_idx: 0x%x\n",
981 pending_idx);
982 BUG();
983 }
984 queue->grant_tx_handle[pending_idx] = handle;
985 }
986
987 static inline void xenvif_grant_handle_reset(struct xenvif_queue *queue,
988 u16 pending_idx)
989 {
990 if (unlikely(queue->grant_tx_handle[pending_idx] ==
991 NETBACK_INVALID_HANDLE)) {
992 netdev_err(queue->vif->dev,
993 "Trying to unmap invalid handle! pending_idx: 0x%x\n",
994 pending_idx);
995 BUG();
996 }
997 queue->grant_tx_handle[pending_idx] = NETBACK_INVALID_HANDLE;
998 }
999
1000 static int xenvif_tx_check_gop(struct xenvif_queue *queue,
1001 struct sk_buff *skb,
1002 struct gnttab_map_grant_ref **gopp_map,
1003 struct gnttab_copy **gopp_copy)
1004 {
1005 struct gnttab_map_grant_ref *gop_map = *gopp_map;
1006 u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
1007 /* This always points to the shinfo of the skb being checked, which
1008 * could be either the first or the one on the frag_list
1009 */
1010 struct skb_shared_info *shinfo = skb_shinfo(skb);
1011 /* If this is non-NULL, we are currently checking the frag_list skb, and
1012 * this points to the shinfo of the first one
1013 */
1014 struct skb_shared_info *first_shinfo = NULL;
1015 int nr_frags = shinfo->nr_frags;
1016 const bool sharedslot = nr_frags &&
1017 frag_get_pending_idx(&shinfo->frags[0]) == pending_idx;
1018 int i, err;
1019
1020 /* Check status of header. */
1021 err = (*gopp_copy)->status;
1022 if (unlikely(err)) {
1023 if (net_ratelimit())
1024 netdev_dbg(queue->vif->dev,
1025 "Grant copy of header failed! status: %d pending_idx: %u ref: %u\n",
1026 (*gopp_copy)->status,
1027 pending_idx,
1028 (*gopp_copy)->source.u.ref);
1029 /* The first frag might still have this slot mapped */
1030 if (!sharedslot)
1031 xenvif_idx_release(queue, pending_idx,
1032 XEN_NETIF_RSP_ERROR);
1033 }
1034 (*gopp_copy)++;
1035
1036 check_frags:
1037 for (i = 0; i < nr_frags; i++, gop_map++) {
1038 int j, newerr;
1039
1040 pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
1041
1042 /* Check error status: if okay then remember grant handle. */
1043 newerr = gop_map->status;
1044
1045 if (likely(!newerr)) {
1046 xenvif_grant_handle_set(queue,
1047 pending_idx,
1048 gop_map->handle);
1049 /* Had a previous error? Invalidate this fragment. */
1050 if (unlikely(err)) {
1051 xenvif_idx_unmap(queue, pending_idx);
1052 /* If the mapping of the first frag was OK, but
1053 * the header's copy failed, and they are
1054 * sharing a slot, send an error
1055 */
1056 if (i == 0 && sharedslot)
1057 xenvif_idx_release(queue, pending_idx,
1058 XEN_NETIF_RSP_ERROR);
1059 else
1060 xenvif_idx_release(queue, pending_idx,
1061 XEN_NETIF_RSP_OKAY);
1062 }
1063 continue;
1064 }
1065
1066 /* Error on this fragment: respond to client with an error. */
1067 if (net_ratelimit())
1068 netdev_dbg(queue->vif->dev,
1069 "Grant map of %d. frag failed! status: %d pending_idx: %u ref: %u\n",
1070 i,
1071 gop_map->status,
1072 pending_idx,
1073 gop_map->ref);
1074
1075 xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_ERROR);
1076
1077 /* Not the first error? Preceding frags already invalidated. */
1078 if (err)
1079 continue;
1080
1081 /* First error: if the header haven't shared a slot with the
1082 * first frag, release it as well.
1083 */
1084 if (!sharedslot)
1085 xenvif_idx_release(queue,
1086 XENVIF_TX_CB(skb)->pending_idx,
1087 XEN_NETIF_RSP_OKAY);
1088
1089 /* Invalidate preceding fragments of this skb. */
1090 for (j = 0; j < i; j++) {
1091 pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
1092 xenvif_idx_unmap(queue, pending_idx);
1093 xenvif_idx_release(queue, pending_idx,
1094 XEN_NETIF_RSP_OKAY);
1095 }
1096
1097 /* And if we found the error while checking the frag_list, unmap
1098 * the first skb's frags
1099 */
1100 if (first_shinfo) {
1101 for (j = 0; j < first_shinfo->nr_frags; j++) {
1102 pending_idx = frag_get_pending_idx(&first_shinfo->frags[j]);
1103 xenvif_idx_unmap(queue, pending_idx);
1104 xenvif_idx_release(queue, pending_idx,
1105 XEN_NETIF_RSP_OKAY);
1106 }
1107 }
1108
1109 /* Remember the error: invalidate all subsequent fragments. */
1110 err = newerr;
1111 }
1112
1113 if (skb_has_frag_list(skb) && !first_shinfo) {
1114 first_shinfo = skb_shinfo(skb);
1115 shinfo = skb_shinfo(skb_shinfo(skb)->frag_list);
1116 nr_frags = shinfo->nr_frags;
1117
1118 goto check_frags;
1119 }
1120
1121 *gopp_map = gop_map;
1122 return err;
1123 }
1124
1125 static void xenvif_fill_frags(struct xenvif_queue *queue, struct sk_buff *skb)
1126 {
1127 struct skb_shared_info *shinfo = skb_shinfo(skb);
1128 int nr_frags = shinfo->nr_frags;
1129 int i;
1130 u16 prev_pending_idx = INVALID_PENDING_IDX;
1131
1132 for (i = 0; i < nr_frags; i++) {
1133 skb_frag_t *frag = shinfo->frags + i;
1134 struct xen_netif_tx_request *txp;
1135 struct page *page;
1136 u16 pending_idx;
1137
1138 pending_idx = frag_get_pending_idx(frag);
1139
1140 /* If this is not the first frag, chain it to the previous*/
1141 if (prev_pending_idx == INVALID_PENDING_IDX)
1142 skb_shinfo(skb)->destructor_arg =
1143 &callback_param(queue, pending_idx);
1144 else
1145 callback_param(queue, prev_pending_idx).ctx =
1146 &callback_param(queue, pending_idx);
1147
1148 callback_param(queue, pending_idx).ctx = NULL;
1149 prev_pending_idx = pending_idx;
1150
1151 txp = &queue->pending_tx_info[pending_idx].req;
1152 page = virt_to_page(idx_to_kaddr(queue, pending_idx));
1153 __skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
1154 skb->len += txp->size;
1155 skb->data_len += txp->size;
1156 skb->truesize += txp->size;
1157
1158 /* Take an extra reference to offset network stack's put_page */
1159 get_page(queue->mmap_pages[pending_idx]);
1160 }
1161 }
1162
1163 static int xenvif_get_extras(struct xenvif_queue *queue,
1164 struct xen_netif_extra_info *extras,
1165 unsigned int *extra_count,
1166 int work_to_do)
1167 {
1168 struct xen_netif_extra_info extra;
1169 RING_IDX cons = queue->tx.req_cons;
1170
1171 do {
1172 if (unlikely(work_to_do-- <= 0)) {
1173 netdev_err(queue->vif->dev, "Missing extra info\n");
1174 xenvif_fatal_tx_err(queue->vif);
1175 return -EBADR;
1176 }
1177
1178 RING_COPY_REQUEST(&queue->tx, cons, &extra);
1179
1180 queue->tx.req_cons = ++cons;
1181 (*extra_count)++;
1182
1183 if (unlikely(!extra.type ||
1184 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
1185 netdev_err(queue->vif->dev,
1186 "Invalid extra type: %d\n", extra.type);
1187 xenvif_fatal_tx_err(queue->vif);
1188 return -EINVAL;
1189 }
1190
1191 memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
1192 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
1193
1194 return work_to_do;
1195 }
1196
1197 static int xenvif_set_skb_gso(struct xenvif *vif,
1198 struct sk_buff *skb,
1199 struct xen_netif_extra_info *gso)
1200 {
1201 if (!gso->u.gso.size) {
1202 netdev_err(vif->dev, "GSO size must not be zero.\n");
1203 xenvif_fatal_tx_err(vif);
1204 return -EINVAL;
1205 }
1206
1207 switch (gso->u.gso.type) {
1208 case XEN_NETIF_GSO_TYPE_TCPV4:
1209 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
1210 break;
1211 case XEN_NETIF_GSO_TYPE_TCPV6:
1212 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
1213 break;
1214 default:
1215 netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
1216 xenvif_fatal_tx_err(vif);
1217 return -EINVAL;
1218 }
1219
1220 skb_shinfo(skb)->gso_size = gso->u.gso.size;
1221 /* gso_segs will be calculated later */
1222
1223 return 0;
1224 }
1225
1226 static int checksum_setup(struct xenvif_queue *queue, struct sk_buff *skb)
1227 {
1228 bool recalculate_partial_csum = false;
1229
1230 /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
1231 * peers can fail to set NETRXF_csum_blank when sending a GSO
1232 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
1233 * recalculate the partial checksum.
1234 */
1235 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
1236 queue->stats.rx_gso_checksum_fixup++;
1237 skb->ip_summed = CHECKSUM_PARTIAL;
1238 recalculate_partial_csum = true;
1239 }
1240
1241 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
1242 if (skb->ip_summed != CHECKSUM_PARTIAL)
1243 return 0;
1244
1245 return skb_checksum_setup(skb, recalculate_partial_csum);
1246 }
1247
1248 static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size)
1249 {
1250 u64 now = get_jiffies_64();
1251 u64 next_credit = queue->credit_window_start +
1252 msecs_to_jiffies(queue->credit_usec / 1000);
1253
1254 /* Timer could already be pending in rare cases. */
1255 if (timer_pending(&queue->credit_timeout))
1256 return true;
1257
1258 /* Passed the point where we can replenish credit? */
1259 if (time_after_eq64(now, next_credit)) {
1260 queue->credit_window_start = now;
1261 tx_add_credit(queue);
1262 }
1263
1264 /* Still too big to send right now? Set a callback. */
1265 if (size > queue->remaining_credit) {
1266 queue->credit_timeout.data =
1267 (unsigned long)queue;
1268 mod_timer(&queue->credit_timeout,
1269 next_credit);
1270 queue->credit_window_start = next_credit;
1271
1272 return true;
1273 }
1274
1275 return false;
1276 }
1277
1278 /* No locking is required in xenvif_mcast_add/del() as they are
1279 * only ever invoked from NAPI poll. An RCU list is used because
1280 * xenvif_mcast_match() is called asynchronously, during start_xmit.
1281 */
1282
1283 static int xenvif_mcast_add(struct xenvif *vif, const u8 *addr)
1284 {
1285 struct xenvif_mcast_addr *mcast;
1286
1287 if (vif->fe_mcast_count == XEN_NETBK_MCAST_MAX) {
1288 if (net_ratelimit())
1289 netdev_err(vif->dev,
1290 "Too many multicast addresses\n");
1291 return -ENOSPC;
1292 }
1293
1294 mcast = kzalloc(sizeof(*mcast), GFP_ATOMIC);
1295 if (!mcast)
1296 return -ENOMEM;
1297
1298 ether_addr_copy(mcast->addr, addr);
1299 list_add_tail_rcu(&mcast->entry, &vif->fe_mcast_addr);
1300 vif->fe_mcast_count++;
1301
1302 return 0;
1303 }
1304
1305 static void xenvif_mcast_del(struct xenvif *vif, const u8 *addr)
1306 {
1307 struct xenvif_mcast_addr *mcast;
1308
1309 list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
1310 if (ether_addr_equal(addr, mcast->addr)) {
1311 --vif->fe_mcast_count;
1312 list_del_rcu(&mcast->entry);
1313 kfree_rcu(mcast, rcu);
1314 break;
1315 }
1316 }
1317 }
1318
1319 bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr)
1320 {
1321 struct xenvif_mcast_addr *mcast;
1322
1323 rcu_read_lock();
1324 list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
1325 if (ether_addr_equal(addr, mcast->addr)) {
1326 rcu_read_unlock();
1327 return true;
1328 }
1329 }
1330 rcu_read_unlock();
1331
1332 return false;
1333 }
1334
1335 void xenvif_mcast_addr_list_free(struct xenvif *vif)
1336 {
1337 /* No need for locking or RCU here. NAPI poll and TX queue
1338 * are stopped.
1339 */
1340 while (!list_empty(&vif->fe_mcast_addr)) {
1341 struct xenvif_mcast_addr *mcast;
1342
1343 mcast = list_first_entry(&vif->fe_mcast_addr,
1344 struct xenvif_mcast_addr,
1345 entry);
1346 --vif->fe_mcast_count;
1347 list_del(&mcast->entry);
1348 kfree(mcast);
1349 }
1350 }
1351
1352 static void xenvif_tx_build_gops(struct xenvif_queue *queue,
1353 int budget,
1354 unsigned *copy_ops,
1355 unsigned *map_ops)
1356 {
1357 struct gnttab_map_grant_ref *gop = queue->tx_map_ops;
1358 struct sk_buff *skb, *nskb;
1359 int ret;
1360 unsigned int frag_overflow;
1361
1362 while (skb_queue_len(&queue->tx_queue) < budget) {
1363 struct xen_netif_tx_request txreq;
1364 struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
1365 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
1366 unsigned int extra_count;
1367 u16 pending_idx;
1368 RING_IDX idx;
1369 int work_to_do;
1370 unsigned int data_len;
1371 pending_ring_idx_t index;
1372
1373 if (queue->tx.sring->req_prod - queue->tx.req_cons >
1374 XEN_NETIF_TX_RING_SIZE) {
1375 netdev_err(queue->vif->dev,
1376 "Impossible number of requests. "
1377 "req_prod %d, req_cons %d, size %ld\n",
1378 queue->tx.sring->req_prod, queue->tx.req_cons,
1379 XEN_NETIF_TX_RING_SIZE);
1380 xenvif_fatal_tx_err(queue->vif);
1381 break;
1382 }
1383
1384 work_to_do = RING_HAS_UNCONSUMED_REQUESTS(&queue->tx);
1385 if (!work_to_do)
1386 break;
1387
1388 idx = queue->tx.req_cons;
1389 rmb(); /* Ensure that we see the request before we copy it. */
1390 RING_COPY_REQUEST(&queue->tx, idx, &txreq);
1391
1392 /* Credit-based scheduling. */
1393 if (txreq.size > queue->remaining_credit &&
1394 tx_credit_exceeded(queue, txreq.size))
1395 break;
1396
1397 queue->remaining_credit -= txreq.size;
1398
1399 work_to_do--;
1400 queue->tx.req_cons = ++idx;
1401
1402 memset(extras, 0, sizeof(extras));
1403 extra_count = 0;
1404 if (txreq.flags & XEN_NETTXF_extra_info) {
1405 work_to_do = xenvif_get_extras(queue, extras,
1406 &extra_count,
1407 work_to_do);
1408 idx = queue->tx.req_cons;
1409 if (unlikely(work_to_do < 0))
1410 break;
1411 }
1412
1413 if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1].type) {
1414 struct xen_netif_extra_info *extra;
1415
1416 extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1];
1417 ret = xenvif_mcast_add(queue->vif, extra->u.mcast.addr);
1418
1419 make_tx_response(queue, &txreq, extra_count,
1420 (ret == 0) ?
1421 XEN_NETIF_RSP_OKAY :
1422 XEN_NETIF_RSP_ERROR);
1423 push_tx_responses(queue);
1424 continue;
1425 }
1426
1427 if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1].type) {
1428 struct xen_netif_extra_info *extra;
1429
1430 extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1];
1431 xenvif_mcast_del(queue->vif, extra->u.mcast.addr);
1432
1433 make_tx_response(queue, &txreq, extra_count,
1434 XEN_NETIF_RSP_OKAY);
1435 push_tx_responses(queue);
1436 continue;
1437 }
1438
1439 ret = xenvif_count_requests(queue, &txreq, extra_count,
1440 txfrags, work_to_do);
1441 if (unlikely(ret < 0))
1442 break;
1443
1444 idx += ret;
1445
1446 if (unlikely(txreq.size < ETH_HLEN)) {
1447 netdev_dbg(queue->vif->dev,
1448 "Bad packet size: %d\n", txreq.size);
1449 xenvif_tx_err(queue, &txreq, extra_count, idx);
1450 break;
1451 }
1452
1453 /* No crossing a page as the payload mustn't fragment. */
1454 if (unlikely((txreq.offset + txreq.size) > XEN_PAGE_SIZE)) {
1455 netdev_err(queue->vif->dev,
1456 "txreq.offset: %u, size: %u, end: %lu\n",
1457 txreq.offset, txreq.size,
1458 (unsigned long)(txreq.offset&~XEN_PAGE_MASK) + txreq.size);
1459 xenvif_fatal_tx_err(queue->vif);
1460 break;
1461 }
1462
1463 index = pending_index(queue->pending_cons);
1464 pending_idx = queue->pending_ring[index];
1465
1466 data_len = (txreq.size > XEN_NETBACK_TX_COPY_LEN &&
1467 ret < XEN_NETBK_LEGACY_SLOTS_MAX) ?
1468 XEN_NETBACK_TX_COPY_LEN : txreq.size;
1469
1470 skb = xenvif_alloc_skb(data_len);
1471 if (unlikely(skb == NULL)) {
1472 netdev_dbg(queue->vif->dev,
1473 "Can't allocate a skb in start_xmit.\n");
1474 xenvif_tx_err(queue, &txreq, extra_count, idx);
1475 break;
1476 }
1477
1478 skb_shinfo(skb)->nr_frags = ret;
1479 if (data_len < txreq.size)
1480 skb_shinfo(skb)->nr_frags++;
1481 /* At this point shinfo->nr_frags is in fact the number of
1482 * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
1483 */
1484 frag_overflow = 0;
1485 nskb = NULL;
1486 if (skb_shinfo(skb)->nr_frags > MAX_SKB_FRAGS) {
1487 frag_overflow = skb_shinfo(skb)->nr_frags - MAX_SKB_FRAGS;
1488 BUG_ON(frag_overflow > MAX_SKB_FRAGS);
1489 skb_shinfo(skb)->nr_frags = MAX_SKB_FRAGS;
1490 nskb = xenvif_alloc_skb(0);
1491 if (unlikely(nskb == NULL)) {
1492 kfree_skb(skb);
1493 xenvif_tx_err(queue, &txreq, extra_count, idx);
1494 if (net_ratelimit())
1495 netdev_err(queue->vif->dev,
1496 "Can't allocate the frag_list skb.\n");
1497 break;
1498 }
1499 }
1500
1501 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1502 struct xen_netif_extra_info *gso;
1503 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1504
1505 if (xenvif_set_skb_gso(queue->vif, skb, gso)) {
1506 /* Failure in xenvif_set_skb_gso is fatal. */
1507 kfree_skb(skb);
1508 kfree_skb(nskb);
1509 break;
1510 }
1511 }
1512
1513 if (extras[XEN_NETIF_EXTRA_TYPE_HASH - 1].type) {
1514 struct xen_netif_extra_info *extra;
1515 enum pkt_hash_types type = PKT_HASH_TYPE_NONE;
1516
1517 extra = &extras[XEN_NETIF_EXTRA_TYPE_HASH - 1];
1518
1519 switch (extra->u.hash.type) {
1520 case _XEN_NETIF_CTRL_HASH_TYPE_IPV4:
1521 case _XEN_NETIF_CTRL_HASH_TYPE_IPV6:
1522 type = PKT_HASH_TYPE_L3;
1523 break;
1524
1525 case _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP:
1526 case _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP:
1527 type = PKT_HASH_TYPE_L4;
1528 break;
1529
1530 default:
1531 break;
1532 }
1533
1534 if (type != PKT_HASH_TYPE_NONE)
1535 skb_set_hash(skb,
1536 *(u32 *)extra->u.hash.value,
1537 type);
1538 }
1539
1540 XENVIF_TX_CB(skb)->pending_idx = pending_idx;
1541
1542 __skb_put(skb, data_len);
1543 queue->tx_copy_ops[*copy_ops].source.u.ref = txreq.gref;
1544 queue->tx_copy_ops[*copy_ops].source.domid = queue->vif->domid;
1545 queue->tx_copy_ops[*copy_ops].source.offset = txreq.offset;
1546
1547 queue->tx_copy_ops[*copy_ops].dest.u.gmfn =
1548 virt_to_gfn(skb->data);
1549 queue->tx_copy_ops[*copy_ops].dest.domid = DOMID_SELF;
1550 queue->tx_copy_ops[*copy_ops].dest.offset =
1551 offset_in_page(skb->data) & ~XEN_PAGE_MASK;
1552
1553 queue->tx_copy_ops[*copy_ops].len = data_len;
1554 queue->tx_copy_ops[*copy_ops].flags = GNTCOPY_source_gref;
1555
1556 (*copy_ops)++;
1557
1558 if (data_len < txreq.size) {
1559 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
1560 pending_idx);
1561 xenvif_tx_create_map_op(queue, pending_idx, &txreq,
1562 extra_count, gop);
1563 gop++;
1564 } else {
1565 frag_set_pending_idx(&skb_shinfo(skb)->frags[0],
1566 INVALID_PENDING_IDX);
1567 memcpy(&queue->pending_tx_info[pending_idx].req,
1568 &txreq, sizeof(txreq));
1569 queue->pending_tx_info[pending_idx].extra_count =
1570 extra_count;
1571 }
1572
1573 queue->pending_cons++;
1574
1575 gop = xenvif_get_requests(queue, skb, txfrags, gop,
1576 frag_overflow, nskb);
1577
1578 __skb_queue_tail(&queue->tx_queue, skb);
1579
1580 queue->tx.req_cons = idx;
1581
1582 if (((gop-queue->tx_map_ops) >= ARRAY_SIZE(queue->tx_map_ops)) ||
1583 (*copy_ops >= ARRAY_SIZE(queue->tx_copy_ops)))
1584 break;
1585 }
1586
1587 (*map_ops) = gop - queue->tx_map_ops;
1588 return;
1589 }
1590
1591 /* Consolidate skb with a frag_list into a brand new one with local pages on
1592 * frags. Returns 0 or -ENOMEM if can't allocate new pages.
1593 */
1594 static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *skb)
1595 {
1596 unsigned int offset = skb_headlen(skb);
1597 skb_frag_t frags[MAX_SKB_FRAGS];
1598 int i, f;
1599 struct ubuf_info *uarg;
1600 struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
1601
1602 queue->stats.tx_zerocopy_sent += 2;
1603 queue->stats.tx_frag_overflow++;
1604
1605 xenvif_fill_frags(queue, nskb);
1606 /* Subtract frags size, we will correct it later */
1607 skb->truesize -= skb->data_len;
1608 skb->len += nskb->len;
1609 skb->data_len += nskb->len;
1610
1611 /* create a brand new frags array and coalesce there */
1612 for (i = 0; offset < skb->len; i++) {
1613 struct page *page;
1614 unsigned int len;
1615
1616 BUG_ON(i >= MAX_SKB_FRAGS);
1617 page = alloc_page(GFP_ATOMIC);
1618 if (!page) {
1619 int j;
1620 skb->truesize += skb->data_len;
1621 for (j = 0; j < i; j++)
1622 put_page(frags[j].page.p);
1623 return -ENOMEM;
1624 }
1625
1626 if (offset + PAGE_SIZE < skb->len)
1627 len = PAGE_SIZE;
1628 else
1629 len = skb->len - offset;
1630 if (skb_copy_bits(skb, offset, page_address(page), len))
1631 BUG();
1632
1633 offset += len;
1634 frags[i].page.p = page;
1635 frags[i].page_offset = 0;
1636 skb_frag_size_set(&frags[i], len);
1637 }
1638
1639 /* Copied all the bits from the frag list -- free it. */
1640 skb_frag_list_init(skb);
1641 xenvif_skb_zerocopy_prepare(queue, nskb);
1642 kfree_skb(nskb);
1643
1644 /* Release all the original (foreign) frags. */
1645 for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
1646 skb_frag_unref(skb, f);
1647 uarg = skb_shinfo(skb)->destructor_arg;
1648 /* increase inflight counter to offset decrement in callback */
1649 atomic_inc(&queue->inflight_packets);
1650 uarg->callback(uarg, true);
1651 skb_shinfo(skb)->destructor_arg = NULL;
1652
1653 /* Fill the skb with the new (local) frags. */
1654 memcpy(skb_shinfo(skb)->frags, frags, i * sizeof(skb_frag_t));
1655 skb_shinfo(skb)->nr_frags = i;
1656 skb->truesize += i * PAGE_SIZE;
1657
1658 return 0;
1659 }
1660
1661 static int xenvif_tx_submit(struct xenvif_queue *queue)
1662 {
1663 struct gnttab_map_grant_ref *gop_map = queue->tx_map_ops;
1664 struct gnttab_copy *gop_copy = queue->tx_copy_ops;
1665 struct sk_buff *skb;
1666 int work_done = 0;
1667
1668 while ((skb = __skb_dequeue(&queue->tx_queue)) != NULL) {
1669 struct xen_netif_tx_request *txp;
1670 u16 pending_idx;
1671 unsigned data_len;
1672
1673 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
1674 txp = &queue->pending_tx_info[pending_idx].req;
1675
1676 /* Check the remap error code. */
1677 if (unlikely(xenvif_tx_check_gop(queue, skb, &gop_map, &gop_copy))) {
1678 /* If there was an error, xenvif_tx_check_gop is
1679 * expected to release all the frags which were mapped,
1680 * so kfree_skb shouldn't do it again
1681 */
1682 skb_shinfo(skb)->nr_frags = 0;
1683 if (skb_has_frag_list(skb)) {
1684 struct sk_buff *nskb =
1685 skb_shinfo(skb)->frag_list;
1686 skb_shinfo(nskb)->nr_frags = 0;
1687 }
1688 kfree_skb(skb);
1689 continue;
1690 }
1691
1692 data_len = skb->len;
1693 callback_param(queue, pending_idx).ctx = NULL;
1694 if (data_len < txp->size) {
1695 /* Append the packet payload as a fragment. */
1696 txp->offset += data_len;
1697 txp->size -= data_len;
1698 } else {
1699 /* Schedule a response immediately. */
1700 xenvif_idx_release(queue, pending_idx,
1701 XEN_NETIF_RSP_OKAY);
1702 }
1703
1704 if (txp->flags & XEN_NETTXF_csum_blank)
1705 skb->ip_summed = CHECKSUM_PARTIAL;
1706 else if (txp->flags & XEN_NETTXF_data_validated)
1707 skb->ip_summed = CHECKSUM_UNNECESSARY;
1708
1709 xenvif_fill_frags(queue, skb);
1710
1711 if (unlikely(skb_has_frag_list(skb))) {
1712 if (xenvif_handle_frag_list(queue, skb)) {
1713 if (net_ratelimit())
1714 netdev_err(queue->vif->dev,
1715 "Not enough memory to consolidate frag_list!\n");
1716 xenvif_skb_zerocopy_prepare(queue, skb);
1717 kfree_skb(skb);
1718 continue;
1719 }
1720 }
1721
1722 skb->dev = queue->vif->dev;
1723 skb->protocol = eth_type_trans(skb, skb->dev);
1724 skb_reset_network_header(skb);
1725
1726 if (checksum_setup(queue, skb)) {
1727 netdev_dbg(queue->vif->dev,
1728 "Can't setup checksum in net_tx_action\n");
1729 /* We have to set this flag to trigger the callback */
1730 if (skb_shinfo(skb)->destructor_arg)
1731 xenvif_skb_zerocopy_prepare(queue, skb);
1732 kfree_skb(skb);
1733 continue;
1734 }
1735
1736 skb_probe_transport_header(skb, 0);
1737
1738 /* If the packet is GSO then we will have just set up the
1739 * transport header offset in checksum_setup so it's now
1740 * straightforward to calculate gso_segs.
1741 */
1742 if (skb_is_gso(skb)) {
1743 int mss = skb_shinfo(skb)->gso_size;
1744 int hdrlen = skb_transport_header(skb) -
1745 skb_mac_header(skb) +
1746 tcp_hdrlen(skb);
1747
1748 skb_shinfo(skb)->gso_segs =
1749 DIV_ROUND_UP(skb->len - hdrlen, mss);
1750 }
1751
1752 queue->stats.rx_bytes += skb->len;
1753 queue->stats.rx_packets++;
1754
1755 work_done++;
1756
1757 /* Set this flag right before netif_receive_skb, otherwise
1758 * someone might think this packet already left netback, and
1759 * do a skb_copy_ubufs while we are still in control of the
1760 * skb. E.g. the __pskb_pull_tail earlier can do such thing.
1761 */
1762 if (skb_shinfo(skb)->destructor_arg) {
1763 xenvif_skb_zerocopy_prepare(queue, skb);
1764 queue->stats.tx_zerocopy_sent++;
1765 }
1766
1767 netif_receive_skb(skb);
1768 }
1769
1770 return work_done;
1771 }
1772
1773 void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success)
1774 {
1775 unsigned long flags;
1776 pending_ring_idx_t index;
1777 struct xenvif_queue *queue = ubuf_to_queue(ubuf);
1778
1779 /* This is the only place where we grab this lock, to protect callbacks
1780 * from each other.
1781 */
1782 spin_lock_irqsave(&queue->callback_lock, flags);
1783 do {
1784 u16 pending_idx = ubuf->desc;
1785 ubuf = (struct ubuf_info *) ubuf->ctx;
1786 BUG_ON(queue->dealloc_prod - queue->dealloc_cons >=
1787 MAX_PENDING_REQS);
1788 index = pending_index(queue->dealloc_prod);
1789 queue->dealloc_ring[index] = pending_idx;
1790 /* Sync with xenvif_tx_dealloc_action:
1791 * insert idx then incr producer.
1792 */
1793 smp_wmb();
1794 queue->dealloc_prod++;
1795 } while (ubuf);
1796 spin_unlock_irqrestore(&queue->callback_lock, flags);
1797
1798 if (likely(zerocopy_success))
1799 queue->stats.tx_zerocopy_success++;
1800 else
1801 queue->stats.tx_zerocopy_fail++;
1802 xenvif_skb_zerocopy_complete(queue);
1803 }
1804
1805 static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue)
1806 {
1807 struct gnttab_unmap_grant_ref *gop;
1808 pending_ring_idx_t dc, dp;
1809 u16 pending_idx, pending_idx_release[MAX_PENDING_REQS];
1810 unsigned int i = 0;
1811
1812 dc = queue->dealloc_cons;
1813 gop = queue->tx_unmap_ops;
1814
1815 /* Free up any grants we have finished using */
1816 do {
1817 dp = queue->dealloc_prod;
1818
1819 /* Ensure we see all indices enqueued by all
1820 * xenvif_zerocopy_callback().
1821 */
1822 smp_rmb();
1823
1824 while (dc != dp) {
1825 BUG_ON(gop - queue->tx_unmap_ops >= MAX_PENDING_REQS);
1826 pending_idx =
1827 queue->dealloc_ring[pending_index(dc++)];
1828
1829 pending_idx_release[gop - queue->tx_unmap_ops] =
1830 pending_idx;
1831 queue->pages_to_unmap[gop - queue->tx_unmap_ops] =
1832 queue->mmap_pages[pending_idx];
1833 gnttab_set_unmap_op(gop,
1834 idx_to_kaddr(queue, pending_idx),
1835 GNTMAP_host_map,
1836 queue->grant_tx_handle[pending_idx]);
1837 xenvif_grant_handle_reset(queue, pending_idx);
1838 ++gop;
1839 }
1840
1841 } while (dp != queue->dealloc_prod);
1842
1843 queue->dealloc_cons = dc;
1844
1845 if (gop - queue->tx_unmap_ops > 0) {
1846 int ret;
1847 ret = gnttab_unmap_refs(queue->tx_unmap_ops,
1848 NULL,
1849 queue->pages_to_unmap,
1850 gop - queue->tx_unmap_ops);
1851 if (ret) {
1852 netdev_err(queue->vif->dev, "Unmap fail: nr_ops %tu ret %d\n",
1853 gop - queue->tx_unmap_ops, ret);
1854 for (i = 0; i < gop - queue->tx_unmap_ops; ++i) {
1855 if (gop[i].status != GNTST_okay)
1856 netdev_err(queue->vif->dev,
1857 " host_addr: 0x%llx handle: 0x%x status: %d\n",
1858 gop[i].host_addr,
1859 gop[i].handle,
1860 gop[i].status);
1861 }
1862 BUG();
1863 }
1864 }
1865
1866 for (i = 0; i < gop - queue->tx_unmap_ops; ++i)
1867 xenvif_idx_release(queue, pending_idx_release[i],
1868 XEN_NETIF_RSP_OKAY);
1869 }
1870
1871
1872 /* Called after netfront has transmitted */
1873 int xenvif_tx_action(struct xenvif_queue *queue, int budget)
1874 {
1875 unsigned nr_mops, nr_cops = 0;
1876 int work_done, ret;
1877
1878 if (unlikely(!tx_work_todo(queue)))
1879 return 0;
1880
1881 xenvif_tx_build_gops(queue, budget, &nr_cops, &nr_mops);
1882
1883 if (nr_cops == 0)
1884 return 0;
1885
1886 gnttab_batch_copy(queue->tx_copy_ops, nr_cops);
1887 if (nr_mops != 0) {
1888 ret = gnttab_map_refs(queue->tx_map_ops,
1889 NULL,
1890 queue->pages_to_map,
1891 nr_mops);
1892 BUG_ON(ret);
1893 }
1894
1895 work_done = xenvif_tx_submit(queue);
1896
1897 return work_done;
1898 }
1899
1900 static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
1901 u8 status)
1902 {
1903 struct pending_tx_info *pending_tx_info;
1904 pending_ring_idx_t index;
1905 unsigned long flags;
1906
1907 pending_tx_info = &queue->pending_tx_info[pending_idx];
1908
1909 spin_lock_irqsave(&queue->response_lock, flags);
1910
1911 make_tx_response(queue, &pending_tx_info->req,
1912 pending_tx_info->extra_count, status);
1913
1914 /* Release the pending index before pusing the Tx response so
1915 * its available before a new Tx request is pushed by the
1916 * frontend.
1917 */
1918 index = pending_index(queue->pending_prod++);
1919 queue->pending_ring[index] = pending_idx;
1920
1921 push_tx_responses(queue);
1922
1923 spin_unlock_irqrestore(&queue->response_lock, flags);
1924 }
1925
1926
1927 static void make_tx_response(struct xenvif_queue *queue,
1928 struct xen_netif_tx_request *txp,
1929 unsigned int extra_count,
1930 s8 st)
1931 {
1932 RING_IDX i = queue->tx.rsp_prod_pvt;
1933 struct xen_netif_tx_response *resp;
1934
1935 resp = RING_GET_RESPONSE(&queue->tx, i);
1936 resp->id = txp->id;
1937 resp->status = st;
1938
1939 while (extra_count-- != 0)
1940 RING_GET_RESPONSE(&queue->tx, ++i)->status = XEN_NETIF_RSP_NULL;
1941
1942 queue->tx.rsp_prod_pvt = ++i;
1943 }
1944
1945 static void push_tx_responses(struct xenvif_queue *queue)
1946 {
1947 int notify;
1948
1949 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->tx, notify);
1950 if (notify)
1951 notify_remote_via_irq(queue->tx_irq);
1952 }
1953
1954 static struct xen_netif_rx_response *make_rx_response(struct xenvif_queue *queue,
1955 u16 id,
1956 s8 st,
1957 u16 offset,
1958 u16 size,
1959 u16 flags)
1960 {
1961 RING_IDX i = queue->rx.rsp_prod_pvt;
1962 struct xen_netif_rx_response *resp;
1963
1964 resp = RING_GET_RESPONSE(&queue->rx, i);
1965 resp->offset = offset;
1966 resp->flags = flags;
1967 resp->id = id;
1968 resp->status = (s16)size;
1969 if (st < 0)
1970 resp->status = (s16)st;
1971
1972 queue->rx.rsp_prod_pvt = ++i;
1973
1974 return resp;
1975 }
1976
1977 void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx)
1978 {
1979 int ret;
1980 struct gnttab_unmap_grant_ref tx_unmap_op;
1981
1982 gnttab_set_unmap_op(&tx_unmap_op,
1983 idx_to_kaddr(queue, pending_idx),
1984 GNTMAP_host_map,
1985 queue->grant_tx_handle[pending_idx]);
1986 xenvif_grant_handle_reset(queue, pending_idx);
1987
1988 ret = gnttab_unmap_refs(&tx_unmap_op, NULL,
1989 &queue->mmap_pages[pending_idx], 1);
1990 if (ret) {
1991 netdev_err(queue->vif->dev,
1992 "Unmap fail: ret: %d pending_idx: %d host_addr: %llx handle: 0x%x status: %d\n",
1993 ret,
1994 pending_idx,
1995 tx_unmap_op.host_addr,
1996 tx_unmap_op.handle,
1997 tx_unmap_op.status);
1998 BUG();
1999 }
2000 }
2001
2002 static inline int tx_work_todo(struct xenvif_queue *queue)
2003 {
2004 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&queue->tx)))
2005 return 1;
2006
2007 return 0;
2008 }
2009
2010 static inline bool tx_dealloc_work_todo(struct xenvif_queue *queue)
2011 {
2012 return queue->dealloc_cons != queue->dealloc_prod;
2013 }
2014
2015 void xenvif_unmap_frontend_data_rings(struct xenvif_queue *queue)
2016 {
2017 if (queue->tx.sring)
2018 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
2019 queue->tx.sring);
2020 if (queue->rx.sring)
2021 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
2022 queue->rx.sring);
2023 }
2024
2025 int xenvif_map_frontend_data_rings(struct xenvif_queue *queue,
2026 grant_ref_t tx_ring_ref,
2027 grant_ref_t rx_ring_ref)
2028 {
2029 void *addr;
2030 struct xen_netif_tx_sring *txs;
2031 struct xen_netif_rx_sring *rxs;
2032
2033 int err = -ENOMEM;
2034
2035 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
2036 &tx_ring_ref, 1, &addr);
2037 if (err)
2038 goto err;
2039
2040 txs = (struct xen_netif_tx_sring *)addr;
2041 BACK_RING_INIT(&queue->tx, txs, XEN_PAGE_SIZE);
2042
2043 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
2044 &rx_ring_ref, 1, &addr);
2045 if (err)
2046 goto err;
2047
2048 rxs = (struct xen_netif_rx_sring *)addr;
2049 BACK_RING_INIT(&queue->rx, rxs, XEN_PAGE_SIZE);
2050
2051 return 0;
2052
2053 err:
2054 xenvif_unmap_frontend_data_rings(queue);
2055 return err;
2056 }
2057
2058 static void xenvif_queue_carrier_off(struct xenvif_queue *queue)
2059 {
2060 struct xenvif *vif = queue->vif;
2061
2062 queue->stalled = true;
2063
2064 /* At least one queue has stalled? Disable the carrier. */
2065 spin_lock(&vif->lock);
2066 if (vif->stalled_queues++ == 0) {
2067 netdev_info(vif->dev, "Guest Rx stalled");
2068 netif_carrier_off(vif->dev);
2069 }
2070 spin_unlock(&vif->lock);
2071 }
2072
2073 static void xenvif_queue_carrier_on(struct xenvif_queue *queue)
2074 {
2075 struct xenvif *vif = queue->vif;
2076
2077 queue->last_rx_time = jiffies; /* Reset Rx stall detection. */
2078 queue->stalled = false;
2079
2080 /* All queues are ready? Enable the carrier. */
2081 spin_lock(&vif->lock);
2082 if (--vif->stalled_queues == 0) {
2083 netdev_info(vif->dev, "Guest Rx ready");
2084 netif_carrier_on(vif->dev);
2085 }
2086 spin_unlock(&vif->lock);
2087 }
2088
2089 static bool xenvif_rx_queue_stalled(struct xenvif_queue *queue)
2090 {
2091 RING_IDX prod, cons;
2092
2093 prod = queue->rx.sring->req_prod;
2094 cons = queue->rx.req_cons;
2095
2096 return !queue->stalled && prod - cons < 1
2097 && time_after(jiffies,
2098 queue->last_rx_time + queue->vif->stall_timeout);
2099 }
2100
2101 static bool xenvif_rx_queue_ready(struct xenvif_queue *queue)
2102 {
2103 RING_IDX prod, cons;
2104
2105 prod = queue->rx.sring->req_prod;
2106 cons = queue->rx.req_cons;
2107
2108 return queue->stalled && prod - cons >= 1;
2109 }
2110
2111 static bool xenvif_have_rx_work(struct xenvif_queue *queue)
2112 {
2113 return xenvif_rx_ring_slots_available(queue)
2114 || (queue->vif->stall_timeout &&
2115 (xenvif_rx_queue_stalled(queue)
2116 || xenvif_rx_queue_ready(queue)))
2117 || kthread_should_stop()
2118 || queue->vif->disabled;
2119 }
2120
2121 static long xenvif_rx_queue_timeout(struct xenvif_queue *queue)
2122 {
2123 struct sk_buff *skb;
2124 long timeout;
2125
2126 skb = skb_peek(&queue->rx_queue);
2127 if (!skb)
2128 return MAX_SCHEDULE_TIMEOUT;
2129
2130 timeout = XENVIF_RX_CB(skb)->expires - jiffies;
2131 return timeout < 0 ? 0 : timeout;
2132 }
2133
2134 /* Wait until the guest Rx thread has work.
2135 *
2136 * The timeout needs to be adjusted based on the current head of the
2137 * queue (and not just the head at the beginning). In particular, if
2138 * the queue is initially empty an infinite timeout is used and this
2139 * needs to be reduced when a skb is queued.
2140 *
2141 * This cannot be done with wait_event_timeout() because it only
2142 * calculates the timeout once.
2143 */
2144 static void xenvif_wait_for_rx_work(struct xenvif_queue *queue)
2145 {
2146 DEFINE_WAIT(wait);
2147
2148 if (xenvif_have_rx_work(queue))
2149 return;
2150
2151 for (;;) {
2152 long ret;
2153
2154 prepare_to_wait(&queue->wq, &wait, TASK_INTERRUPTIBLE);
2155 if (xenvif_have_rx_work(queue))
2156 break;
2157 ret = schedule_timeout(xenvif_rx_queue_timeout(queue));
2158 if (!ret)
2159 break;
2160 }
2161 finish_wait(&queue->wq, &wait);
2162 }
2163
2164 int xenvif_kthread_guest_rx(void *data)
2165 {
2166 struct xenvif_queue *queue = data;
2167 struct xenvif *vif = queue->vif;
2168
2169 if (!vif->stall_timeout)
2170 xenvif_queue_carrier_on(queue);
2171
2172 for (;;) {
2173 xenvif_wait_for_rx_work(queue);
2174
2175 if (kthread_should_stop())
2176 break;
2177
2178 /* This frontend is found to be rogue, disable it in
2179 * kthread context. Currently this is only set when
2180 * netback finds out frontend sends malformed packet,
2181 * but we cannot disable the interface in softirq
2182 * context so we defer it here, if this thread is
2183 * associated with queue 0.
2184 */
2185 if (unlikely(vif->disabled && queue->id == 0)) {
2186 xenvif_carrier_off(vif);
2187 break;
2188 }
2189
2190 if (!skb_queue_empty(&queue->rx_queue))
2191 xenvif_rx_action(queue);
2192
2193 /* If the guest hasn't provided any Rx slots for a
2194 * while it's probably not responsive, drop the
2195 * carrier so packets are dropped earlier.
2196 */
2197 if (vif->stall_timeout) {
2198 if (xenvif_rx_queue_stalled(queue))
2199 xenvif_queue_carrier_off(queue);
2200 else if (xenvif_rx_queue_ready(queue))
2201 xenvif_queue_carrier_on(queue);
2202 }
2203
2204 /* Queued packets may have foreign pages from other
2205 * domains. These cannot be queued indefinitely as
2206 * this would starve guests of grant refs and transmit
2207 * slots.
2208 */
2209 xenvif_rx_queue_drop_expired(queue);
2210
2211 xenvif_rx_queue_maybe_wake(queue);
2212
2213 cond_resched();
2214 }
2215
2216 /* Bin any remaining skbs */
2217 xenvif_rx_queue_purge(queue);
2218
2219 return 0;
2220 }
2221
2222 static bool xenvif_dealloc_kthread_should_stop(struct xenvif_queue *queue)
2223 {
2224 /* Dealloc thread must remain running until all inflight
2225 * packets complete.
2226 */
2227 return kthread_should_stop() &&
2228 !atomic_read(&queue->inflight_packets);
2229 }
2230
2231 int xenvif_dealloc_kthread(void *data)
2232 {
2233 struct xenvif_queue *queue = data;
2234
2235 for (;;) {
2236 wait_event_interruptible(queue->dealloc_wq,
2237 tx_dealloc_work_todo(queue) ||
2238 xenvif_dealloc_kthread_should_stop(queue));
2239 if (xenvif_dealloc_kthread_should_stop(queue))
2240 break;
2241
2242 xenvif_tx_dealloc_action(queue);
2243 cond_resched();
2244 }
2245
2246 /* Unmap anything remaining*/
2247 if (tx_dealloc_work_todo(queue))
2248 xenvif_tx_dealloc_action(queue);
2249
2250 return 0;
2251 }
2252
2253 static void make_ctrl_response(struct xenvif *vif,
2254 const struct xen_netif_ctrl_request *req,
2255 u32 status, u32 data)
2256 {
2257 RING_IDX idx = vif->ctrl.rsp_prod_pvt;
2258 struct xen_netif_ctrl_response rsp = {
2259 .id = req->id,
2260 .type = req->type,
2261 .status = status,
2262 .data = data,
2263 };
2264
2265 *RING_GET_RESPONSE(&vif->ctrl, idx) = rsp;
2266 vif->ctrl.rsp_prod_pvt = ++idx;
2267 }
2268
2269 static void push_ctrl_response(struct xenvif *vif)
2270 {
2271 int notify;
2272
2273 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->ctrl, notify);
2274 if (notify)
2275 notify_remote_via_irq(vif->ctrl_irq);
2276 }
2277
2278 static void process_ctrl_request(struct xenvif *vif,
2279 const struct xen_netif_ctrl_request *req)
2280 {
2281 u32 status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED;
2282 u32 data = 0;
2283
2284 switch (req->type) {
2285 case XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM:
2286 status = xenvif_set_hash_alg(vif, req->data[0]);
2287 break;
2288
2289 case XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS:
2290 status = xenvif_get_hash_flags(vif, &data);
2291 break;
2292
2293 case XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS:
2294 status = xenvif_set_hash_flags(vif, req->data[0]);
2295 break;
2296
2297 case XEN_NETIF_CTRL_TYPE_SET_HASH_KEY:
2298 status = xenvif_set_hash_key(vif, req->data[0],
2299 req->data[1]);
2300 break;
2301
2302 case XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE:
2303 status = XEN_NETIF_CTRL_STATUS_SUCCESS;
2304 data = XEN_NETBK_MAX_HASH_MAPPING_SIZE;
2305 break;
2306
2307 case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE:
2308 status = xenvif_set_hash_mapping_size(vif,
2309 req->data[0]);
2310 break;
2311
2312 case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING:
2313 status = xenvif_set_hash_mapping(vif, req->data[0],
2314 req->data[1],
2315 req->data[2]);
2316 break;
2317
2318 default:
2319 break;
2320 }
2321
2322 make_ctrl_response(vif, req, status, data);
2323 push_ctrl_response(vif);
2324 }
2325
2326 static void xenvif_ctrl_action(struct xenvif *vif)
2327 {
2328 for (;;) {
2329 RING_IDX req_prod, req_cons;
2330
2331 req_prod = vif->ctrl.sring->req_prod;
2332 req_cons = vif->ctrl.req_cons;
2333
2334 /* Make sure we can see requests before we process them. */
2335 rmb();
2336
2337 if (req_cons == req_prod)
2338 break;
2339
2340 while (req_cons != req_prod) {
2341 struct xen_netif_ctrl_request req;
2342
2343 RING_COPY_REQUEST(&vif->ctrl, req_cons, &req);
2344 req_cons++;
2345
2346 process_ctrl_request(vif, &req);
2347 }
2348
2349 vif->ctrl.req_cons = req_cons;
2350 vif->ctrl.sring->req_event = req_cons + 1;
2351 }
2352 }
2353
2354 static bool xenvif_ctrl_work_todo(struct xenvif *vif)
2355 {
2356 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->ctrl)))
2357 return 1;
2358
2359 return 0;
2360 }
2361
2362 int xenvif_ctrl_kthread(void *data)
2363 {
2364 struct xenvif *vif = data;
2365
2366 for (;;) {
2367 wait_event_interruptible(vif->ctrl_wq,
2368 xenvif_ctrl_work_todo(vif) ||
2369 kthread_should_stop());
2370 if (kthread_should_stop())
2371 break;
2372
2373 while (xenvif_ctrl_work_todo(vif))
2374 xenvif_ctrl_action(vif);
2375
2376 cond_resched();
2377 }
2378
2379 return 0;
2380 }
2381
2382 static int __init netback_init(void)
2383 {
2384 int rc = 0;
2385
2386 if (!xen_domain())
2387 return -ENODEV;
2388
2389 /* Allow as many queues as there are CPUs if user has not
2390 * specified a value.
2391 */
2392 if (xenvif_max_queues == 0)
2393 xenvif_max_queues = num_online_cpus();
2394
2395 if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
2396 pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
2397 fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX);
2398 fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX;
2399 }
2400
2401 rc = xenvif_xenbus_init();
2402 if (rc)
2403 goto failed_init;
2404
2405 #ifdef CONFIG_DEBUG_FS
2406 xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL);
2407 if (IS_ERR_OR_NULL(xen_netback_dbg_root))
2408 pr_warn("Init of debugfs returned %ld!\n",
2409 PTR_ERR(xen_netback_dbg_root));
2410 #endif /* CONFIG_DEBUG_FS */
2411
2412 return 0;
2413
2414 failed_init:
2415 return rc;
2416 }
2417
2418 module_init(netback_init);
2419
2420 static void __exit netback_fini(void)
2421 {
2422 #ifdef CONFIG_DEBUG_FS
2423 if (!IS_ERR_OR_NULL(xen_netback_dbg_root))
2424 debugfs_remove_recursive(xen_netback_dbg_root);
2425 #endif /* CONFIG_DEBUG_FS */
2426 xenvif_xenbus_fini();
2427 }
2428 module_exit(netback_fini);
2429
2430 MODULE_LICENSE("Dual BSD/GPL");
2431 MODULE_ALIAS("xen-backend:vif");
CRIS linux kernel tree