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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 */
55bool separate_tx_rx_irq = true;
56module_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 */
61unsigned int rx_drain_timeout_msecs = 10000;
62module_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 */
67unsigned int rx_stall_timeout_msecs = 60000;
68module_param(rx_stall_timeout_msecs, uint, 0444);
69
70#define MAX_QUEUES_DEFAULT 8
71unsigned int xenvif_max_queues;
72module_param_named(max_queues, xenvif_max_queues, uint, 0644);
73MODULE_PARM_DESC(max_queues,
74 "Maximum number of queues per virtual interface");
75
76/*
77 * This is the maximum slots a skb can have. If a guest sends a skb
78 * which exceeds this limit it is considered malicious.
79 */
80#define FATAL_SKB_SLOTS_DEFAULT 20
81static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT;
82module_param(fatal_skb_slots, uint, 0444);
83
84/* The amount to copy out of the first guest Tx slot into the skb's
85 * linear area. If the first slot has more data, it will be mapped
86 * and put into the first frag.
87 *
88 * This is sized to avoid pulling headers from the frags for most
89 * TCP/IP packets.
90 */
91#define XEN_NETBACK_TX_COPY_LEN 128
92
93/* This is the maximum number of flows in the hash cache. */
94#define XENVIF_HASH_CACHE_SIZE_DEFAULT 64
95unsigned int xenvif_hash_cache_size = XENVIF_HASH_CACHE_SIZE_DEFAULT;
96module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, 0644);
97MODULE_PARM_DESC(hash_cache_size, "Number of flows in the hash cache");
98
99/* The module parameter tells that we have to put data
100 * for xen-netfront with the XDP_PACKET_HEADROOM offset
101 * needed for XDP processing
102 */
103bool provides_xdp_headroom = true;
104module_param(provides_xdp_headroom, bool, 0644);
105
106static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
107 s8 status);
108
109static void make_tx_response(struct xenvif_queue *queue,
110 const struct xen_netif_tx_request *txp,
111 unsigned int extra_count,
112 s8 status);
113
114static void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
115
116static inline int tx_work_todo(struct xenvif_queue *queue);
117
118static inline unsigned long idx_to_pfn(struct xenvif_queue *queue,
119 u16 idx)
120{
121 return page_to_pfn(queue->mmap_pages[idx]);
122}
123
124static inline unsigned long idx_to_kaddr(struct xenvif_queue *queue,
125 u16 idx)
126{
127 return (unsigned long)pfn_to_kaddr(idx_to_pfn(queue, idx));
128}
129
130#define callback_param(vif, pending_idx) \
131 (vif->pending_tx_info[pending_idx].callback_struct)
132
133/* Find the containing VIF's structure from a pointer in pending_tx_info array
134 */
135static inline struct xenvif_queue *ubuf_to_queue(const struct ubuf_info_msgzc *ubuf)
136{
137 u16 pending_idx = ubuf->desc;
138 struct pending_tx_info *temp =
139 container_of(ubuf, struct pending_tx_info, callback_struct);
140 return container_of(temp - pending_idx,
141 struct xenvif_queue,
142 pending_tx_info[0]);
143}
144
145static u16 frag_get_pending_idx(skb_frag_t *frag)
146{
147 return (u16)skb_frag_off(frag);
148}
149
150static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx)
151{
152 skb_frag_off_set(frag, pending_idx);
153}
154
155static inline pending_ring_idx_t pending_index(unsigned i)
156{
157 return i & (MAX_PENDING_REQS-1);
158}
159
160void xenvif_kick_thread(struct xenvif_queue *queue)
161{
162 wake_up(&queue->wq);
163}
164
165void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue)
166{
167 int more_to_do;
168
169 RING_FINAL_CHECK_FOR_REQUESTS(&queue->tx, more_to_do);
170
171 if (more_to_do)
172 napi_schedule(&queue->napi);
173 else if (atomic_fetch_andnot(NETBK_TX_EOI | NETBK_COMMON_EOI,
174 &queue->eoi_pending) &
175 (NETBK_TX_EOI | NETBK_COMMON_EOI))
176 xen_irq_lateeoi(queue->tx_irq, 0);
177}
178
179static void tx_add_credit(struct xenvif_queue *queue)
180{
181 unsigned long max_burst, max_credit;
182
183 /*
184 * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
185 * Otherwise the interface can seize up due to insufficient credit.
186 */
187 max_burst = max(131072UL, queue->credit_bytes);
188
189 /* Take care that adding a new chunk of credit doesn't wrap to zero. */
190 max_credit = queue->remaining_credit + queue->credit_bytes;
191 if (max_credit < queue->remaining_credit)
192 max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
193
194 queue->remaining_credit = min(max_credit, max_burst);
195 queue->rate_limited = false;
196}
197
198void xenvif_tx_credit_callback(struct timer_list *t)
199{
200 struct xenvif_queue *queue = from_timer(queue, t, credit_timeout);
201 tx_add_credit(queue);
202 xenvif_napi_schedule_or_enable_events(queue);
203}
204
205static void xenvif_tx_err(struct xenvif_queue *queue,
206 struct xen_netif_tx_request *txp,
207 unsigned int extra_count, RING_IDX end)
208{
209 RING_IDX cons = queue->tx.req_cons;
210
211 do {
212 make_tx_response(queue, txp, extra_count, XEN_NETIF_RSP_ERROR);
213 if (cons == end)
214 break;
215 RING_COPY_REQUEST(&queue->tx, cons++, txp);
216 extra_count = 0; /* only the first frag can have extras */
217 } while (1);
218 queue->tx.req_cons = cons;
219}
220
221static void xenvif_fatal_tx_err(struct xenvif *vif)
222{
223 netdev_err(vif->dev, "fatal error; disabling device\n");
224 vif->disabled = true;
225 /* Disable the vif from queue 0's kthread */
226 if (vif->num_queues)
227 xenvif_kick_thread(&vif->queues[0]);
228}
229
230static int xenvif_count_requests(struct xenvif_queue *queue,
231 struct xen_netif_tx_request *first,
232 unsigned int extra_count,
233 struct xen_netif_tx_request *txp,
234 int work_to_do)
235{
236 RING_IDX cons = queue->tx.req_cons;
237 int slots = 0;
238 int drop_err = 0;
239 int more_data;
240
241 if (!(first->flags & XEN_NETTXF_more_data))
242 return 0;
243
244 do {
245 struct xen_netif_tx_request dropped_tx = { 0 };
246
247 if (slots >= work_to_do) {
248 netdev_err(queue->vif->dev,
249 "Asked for %d slots but exceeds this limit\n",
250 work_to_do);
251 xenvif_fatal_tx_err(queue->vif);
252 return -ENODATA;
253 }
254
255 /* This guest is really using too many slots and
256 * considered malicious.
257 */
258 if (unlikely(slots >= fatal_skb_slots)) {
259 netdev_err(queue->vif->dev,
260 "Malicious frontend using %d slots, threshold %u\n",
261 slots, fatal_skb_slots);
262 xenvif_fatal_tx_err(queue->vif);
263 return -E2BIG;
264 }
265
266 /* Xen network protocol had implicit dependency on
267 * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to
268 * the historical MAX_SKB_FRAGS value 18 to honor the
269 * same behavior as before. Any packet using more than
270 * 18 slots but less than fatal_skb_slots slots is
271 * dropped
272 */
273 if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) {
274 if (net_ratelimit())
275 netdev_dbg(queue->vif->dev,
276 "Too many slots (%d) exceeding limit (%d), dropping packet\n",
277 slots, XEN_NETBK_LEGACY_SLOTS_MAX);
278 drop_err = -E2BIG;
279 }
280
281 if (drop_err)
282 txp = &dropped_tx;
283
284 RING_COPY_REQUEST(&queue->tx, cons + slots, txp);
285
286 /* If the guest submitted a frame >= 64 KiB then
287 * first->size overflowed and following slots will
288 * appear to be larger than the frame.
289 *
290 * This cannot be fatal error as there are buggy
291 * frontends that do this.
292 *
293 * Consume all slots and drop the packet.
294 */
295 if (!drop_err && txp->size > first->size) {
296 if (net_ratelimit())
297 netdev_dbg(queue->vif->dev,
298 "Invalid tx request, slot size %u > remaining size %u\n",
299 txp->size, first->size);
300 drop_err = -EIO;
301 }
302
303 first->size -= txp->size;
304 slots++;
305
306 if (unlikely((txp->offset + txp->size) > XEN_PAGE_SIZE)) {
307 netdev_err(queue->vif->dev, "Cross page boundary, txp->offset: %u, size: %u\n",
308 txp->offset, txp->size);
309 xenvif_fatal_tx_err(queue->vif);
310 return -EINVAL;
311 }
312
313 more_data = txp->flags & XEN_NETTXF_more_data;
314
315 if (!drop_err)
316 txp++;
317
318 } while (more_data);
319
320 if (drop_err) {
321 xenvif_tx_err(queue, first, extra_count, cons + slots);
322 return drop_err;
323 }
324
325 return slots;
326}
327
328
329struct xenvif_tx_cb {
330 u16 copy_pending_idx[XEN_NETBK_LEGACY_SLOTS_MAX + 1];
331 u8 copy_count;
332 u32 split_mask;
333};
334
335#define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb)
336#define copy_pending_idx(skb, i) (XENVIF_TX_CB(skb)->copy_pending_idx[i])
337#define copy_count(skb) (XENVIF_TX_CB(skb)->copy_count)
338
339static inline void xenvif_tx_create_map_op(struct xenvif_queue *queue,
340 u16 pending_idx,
341 struct xen_netif_tx_request *txp,
342 unsigned int extra_count,
343 struct gnttab_map_grant_ref *mop)
344{
345 queue->pages_to_map[mop-queue->tx_map_ops] = queue->mmap_pages[pending_idx];
346 gnttab_set_map_op(mop, idx_to_kaddr(queue, pending_idx),
347 GNTMAP_host_map | GNTMAP_readonly,
348 txp->gref, queue->vif->domid);
349
350 memcpy(&queue->pending_tx_info[pending_idx].req, txp,
351 sizeof(*txp));
352 queue->pending_tx_info[pending_idx].extra_count = extra_count;
353}
354
355static inline struct sk_buff *xenvif_alloc_skb(unsigned int size)
356{
357 struct sk_buff *skb =
358 alloc_skb(size + NET_SKB_PAD + NET_IP_ALIGN,
359 GFP_ATOMIC | __GFP_NOWARN);
360
361 BUILD_BUG_ON(sizeof(*XENVIF_TX_CB(skb)) > sizeof(skb->cb));
362 if (unlikely(skb == NULL))
363 return NULL;
364
365 /* Packets passed to netif_rx() must have some headroom. */
366 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
367
368 /* Initialize it here to avoid later surprises */
369 skb_shinfo(skb)->destructor_arg = NULL;
370
371 return skb;
372}
373
374static void xenvif_get_requests(struct xenvif_queue *queue,
375 struct sk_buff *skb,
376 struct xen_netif_tx_request *first,
377 struct xen_netif_tx_request *txfrags,
378 unsigned *copy_ops,
379 unsigned *map_ops,
380 unsigned int frag_overflow,
381 struct sk_buff *nskb,
382 unsigned int extra_count,
383 unsigned int data_len)
384{
385 struct skb_shared_info *shinfo = skb_shinfo(skb);
386 skb_frag_t *frags = shinfo->frags;
387 u16 pending_idx;
388 pending_ring_idx_t index;
389 unsigned int nr_slots;
390 struct gnttab_copy *cop = queue->tx_copy_ops + *copy_ops;
391 struct gnttab_map_grant_ref *gop = queue->tx_map_ops + *map_ops;
392 struct xen_netif_tx_request *txp = first;
393
394 nr_slots = shinfo->nr_frags + frag_overflow + 1;
395
396 copy_count(skb) = 0;
397 XENVIF_TX_CB(skb)->split_mask = 0;
398
399 /* Create copy ops for exactly data_len bytes into the skb head. */
400 __skb_put(skb, data_len);
401 while (data_len > 0) {
402 int amount = data_len > txp->size ? txp->size : data_len;
403 bool split = false;
404
405 cop->source.u.ref = txp->gref;
406 cop->source.domid = queue->vif->domid;
407 cop->source.offset = txp->offset;
408
409 cop->dest.domid = DOMID_SELF;
410 cop->dest.offset = (offset_in_page(skb->data +
411 skb_headlen(skb) -
412 data_len)) & ~XEN_PAGE_MASK;
413 cop->dest.u.gmfn = virt_to_gfn(skb->data + skb_headlen(skb)
414 - data_len);
415
416 /* Don't cross local page boundary! */
417 if (cop->dest.offset + amount > XEN_PAGE_SIZE) {
418 amount = XEN_PAGE_SIZE - cop->dest.offset;
419 XENVIF_TX_CB(skb)->split_mask |= 1U << copy_count(skb);
420 split = true;
421 }
422
423 cop->len = amount;
424 cop->flags = GNTCOPY_source_gref;
425
426 index = pending_index(queue->pending_cons);
427 pending_idx = queue->pending_ring[index];
428 callback_param(queue, pending_idx).ctx = NULL;
429 copy_pending_idx(skb, copy_count(skb)) = pending_idx;
430 if (!split)
431 copy_count(skb)++;
432
433 cop++;
434 data_len -= amount;
435
436 if (amount == txp->size) {
437 /* The copy op covered the full tx_request */
438
439 memcpy(&queue->pending_tx_info[pending_idx].req,
440 txp, sizeof(*txp));
441 queue->pending_tx_info[pending_idx].extra_count =
442 (txp == first) ? extra_count : 0;
443
444 if (txp == first)
445 txp = txfrags;
446 else
447 txp++;
448 queue->pending_cons++;
449 nr_slots--;
450 } else {
451 /* The copy op partially covered the tx_request.
452 * The remainder will be mapped or copied in the next
453 * iteration.
454 */
455 txp->offset += amount;
456 txp->size -= amount;
457 }
458 }
459
460 for (shinfo->nr_frags = 0; nr_slots > 0 && shinfo->nr_frags < MAX_SKB_FRAGS;
461 nr_slots--) {
462 if (unlikely(!txp->size)) {
463 make_tx_response(queue, txp, 0, XEN_NETIF_RSP_OKAY);
464 ++txp;
465 continue;
466 }
467
468 index = pending_index(queue->pending_cons++);
469 pending_idx = queue->pending_ring[index];
470 xenvif_tx_create_map_op(queue, pending_idx, txp,
471 txp == first ? extra_count : 0, gop);
472 frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx);
473 ++shinfo->nr_frags;
474 ++gop;
475
476 if (txp == first)
477 txp = txfrags;
478 else
479 txp++;
480 }
481
482 if (nr_slots > 0) {
483
484 shinfo = skb_shinfo(nskb);
485 frags = shinfo->frags;
486
487 for (shinfo->nr_frags = 0; shinfo->nr_frags < nr_slots; ++txp) {
488 if (unlikely(!txp->size)) {
489 make_tx_response(queue, txp, 0,
490 XEN_NETIF_RSP_OKAY);
491 continue;
492 }
493
494 index = pending_index(queue->pending_cons++);
495 pending_idx = queue->pending_ring[index];
496 xenvif_tx_create_map_op(queue, pending_idx, txp, 0,
497 gop);
498 frag_set_pending_idx(&frags[shinfo->nr_frags],
499 pending_idx);
500 ++shinfo->nr_frags;
501 ++gop;
502 }
503
504 if (shinfo->nr_frags) {
505 skb_shinfo(skb)->frag_list = nskb;
506 nskb = NULL;
507 }
508 }
509
510 if (nskb) {
511 /* A frag_list skb was allocated but it is no longer needed
512 * because enough slots were converted to copy ops above or some
513 * were empty.
514 */
515 kfree_skb(nskb);
516 }
517
518 (*copy_ops) = cop - queue->tx_copy_ops;
519 (*map_ops) = gop - queue->tx_map_ops;
520}
521
522static inline void xenvif_grant_handle_set(struct xenvif_queue *queue,
523 u16 pending_idx,
524 grant_handle_t handle)
525{
526 if (unlikely(queue->grant_tx_handle[pending_idx] !=
527 NETBACK_INVALID_HANDLE)) {
528 netdev_err(queue->vif->dev,
529 "Trying to overwrite active handle! pending_idx: 0x%x\n",
530 pending_idx);
531 BUG();
532 }
533 queue->grant_tx_handle[pending_idx] = handle;
534}
535
536static inline void xenvif_grant_handle_reset(struct xenvif_queue *queue,
537 u16 pending_idx)
538{
539 if (unlikely(queue->grant_tx_handle[pending_idx] ==
540 NETBACK_INVALID_HANDLE)) {
541 netdev_err(queue->vif->dev,
542 "Trying to unmap invalid handle! pending_idx: 0x%x\n",
543 pending_idx);
544 BUG();
545 }
546 queue->grant_tx_handle[pending_idx] = NETBACK_INVALID_HANDLE;
547}
548
549static int xenvif_tx_check_gop(struct xenvif_queue *queue,
550 struct sk_buff *skb,
551 struct gnttab_map_grant_ref **gopp_map,
552 struct gnttab_copy **gopp_copy)
553{
554 struct gnttab_map_grant_ref *gop_map = *gopp_map;
555 u16 pending_idx;
556 /* This always points to the shinfo of the skb being checked, which
557 * could be either the first or the one on the frag_list
558 */
559 struct skb_shared_info *shinfo = skb_shinfo(skb);
560 /* If this is non-NULL, we are currently checking the frag_list skb, and
561 * this points to the shinfo of the first one
562 */
563 struct skb_shared_info *first_shinfo = NULL;
564 int nr_frags = shinfo->nr_frags;
565 const bool sharedslot = nr_frags &&
566 frag_get_pending_idx(&shinfo->frags[0]) ==
567 copy_pending_idx(skb, copy_count(skb) - 1);
568 int i, err = 0;
569
570 for (i = 0; i < copy_count(skb); i++) {
571 int newerr;
572
573 /* Check status of header. */
574 pending_idx = copy_pending_idx(skb, i);
575
576 newerr = (*gopp_copy)->status;
577
578 /* Split copies need to be handled together. */
579 if (XENVIF_TX_CB(skb)->split_mask & (1U << i)) {
580 (*gopp_copy)++;
581 if (!newerr)
582 newerr = (*gopp_copy)->status;
583 }
584 if (likely(!newerr)) {
585 /* The first frag might still have this slot mapped */
586 if (i < copy_count(skb) - 1 || !sharedslot)
587 xenvif_idx_release(queue, pending_idx,
588 XEN_NETIF_RSP_OKAY);
589 } else {
590 err = newerr;
591 if (net_ratelimit())
592 netdev_dbg(queue->vif->dev,
593 "Grant copy of header failed! status: %d pending_idx: %u ref: %u\n",
594 (*gopp_copy)->status,
595 pending_idx,
596 (*gopp_copy)->source.u.ref);
597 /* The first frag might still have this slot mapped */
598 if (i < copy_count(skb) - 1 || !sharedslot)
599 xenvif_idx_release(queue, pending_idx,
600 XEN_NETIF_RSP_ERROR);
601 }
602 (*gopp_copy)++;
603 }
604
605check_frags:
606 for (i = 0; i < nr_frags; i++, gop_map++) {
607 int j, newerr;
608
609 pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
610
611 /* Check error status: if okay then remember grant handle. */
612 newerr = gop_map->status;
613
614 if (likely(!newerr)) {
615 xenvif_grant_handle_set(queue,
616 pending_idx,
617 gop_map->handle);
618 /* Had a previous error? Invalidate this fragment. */
619 if (unlikely(err)) {
620 xenvif_idx_unmap(queue, pending_idx);
621 /* If the mapping of the first frag was OK, but
622 * the header's copy failed, and they are
623 * sharing a slot, send an error
624 */
625 if (i == 0 && !first_shinfo && sharedslot)
626 xenvif_idx_release(queue, pending_idx,
627 XEN_NETIF_RSP_ERROR);
628 else
629 xenvif_idx_release(queue, pending_idx,
630 XEN_NETIF_RSP_OKAY);
631 }
632 continue;
633 }
634
635 /* Error on this fragment: respond to client with an error. */
636 if (net_ratelimit())
637 netdev_dbg(queue->vif->dev,
638 "Grant map of %d. frag failed! status: %d pending_idx: %u ref: %u\n",
639 i,
640 gop_map->status,
641 pending_idx,
642 gop_map->ref);
643
644 xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_ERROR);
645
646 /* Not the first error? Preceding frags already invalidated. */
647 if (err)
648 continue;
649
650 /* Invalidate preceding fragments of this skb. */
651 for (j = 0; j < i; j++) {
652 pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
653 xenvif_idx_unmap(queue, pending_idx);
654 xenvif_idx_release(queue, pending_idx,
655 XEN_NETIF_RSP_OKAY);
656 }
657
658 /* And if we found the error while checking the frag_list, unmap
659 * the first skb's frags
660 */
661 if (first_shinfo) {
662 for (j = 0; j < first_shinfo->nr_frags; j++) {
663 pending_idx = frag_get_pending_idx(&first_shinfo->frags[j]);
664 xenvif_idx_unmap(queue, pending_idx);
665 xenvif_idx_release(queue, pending_idx,
666 XEN_NETIF_RSP_OKAY);
667 }
668 }
669
670 /* Remember the error: invalidate all subsequent fragments. */
671 err = newerr;
672 }
673
674 if (skb_has_frag_list(skb) && !first_shinfo) {
675 first_shinfo = shinfo;
676 shinfo = skb_shinfo(shinfo->frag_list);
677 nr_frags = shinfo->nr_frags;
678
679 goto check_frags;
680 }
681
682 *gopp_map = gop_map;
683 return err;
684}
685
686static void xenvif_fill_frags(struct xenvif_queue *queue, struct sk_buff *skb)
687{
688 struct skb_shared_info *shinfo = skb_shinfo(skb);
689 int nr_frags = shinfo->nr_frags;
690 int i;
691 u16 prev_pending_idx = INVALID_PENDING_IDX;
692
693 for (i = 0; i < nr_frags; i++) {
694 skb_frag_t *frag = shinfo->frags + i;
695 struct xen_netif_tx_request *txp;
696 struct page *page;
697 u16 pending_idx;
698
699 pending_idx = frag_get_pending_idx(frag);
700
701 /* If this is not the first frag, chain it to the previous*/
702 if (prev_pending_idx == INVALID_PENDING_IDX)
703 skb_shinfo(skb)->destructor_arg =
704 &callback_param(queue, pending_idx);
705 else
706 callback_param(queue, prev_pending_idx).ctx =
707 &callback_param(queue, pending_idx);
708
709 callback_param(queue, pending_idx).ctx = NULL;
710 prev_pending_idx = pending_idx;
711
712 txp = &queue->pending_tx_info[pending_idx].req;
713 page = virt_to_page((void *)idx_to_kaddr(queue, pending_idx));
714 __skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
715 skb->len += txp->size;
716 skb->data_len += txp->size;
717 skb->truesize += txp->size;
718
719 /* Take an extra reference to offset network stack's put_page */
720 get_page(queue->mmap_pages[pending_idx]);
721 }
722}
723
724static int xenvif_get_extras(struct xenvif_queue *queue,
725 struct xen_netif_extra_info *extras,
726 unsigned int *extra_count,
727 int work_to_do)
728{
729 struct xen_netif_extra_info extra;
730 RING_IDX cons = queue->tx.req_cons;
731
732 do {
733 if (unlikely(work_to_do-- <= 0)) {
734 netdev_err(queue->vif->dev, "Missing extra info\n");
735 xenvif_fatal_tx_err(queue->vif);
736 return -EBADR;
737 }
738
739 RING_COPY_REQUEST(&queue->tx, cons, &extra);
740
741 queue->tx.req_cons = ++cons;
742 (*extra_count)++;
743
744 if (unlikely(!extra.type ||
745 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
746 netdev_err(queue->vif->dev,
747 "Invalid extra type: %d\n", extra.type);
748 xenvif_fatal_tx_err(queue->vif);
749 return -EINVAL;
750 }
751
752 memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
753 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
754
755 return work_to_do;
756}
757
758static int xenvif_set_skb_gso(struct xenvif *vif,
759 struct sk_buff *skb,
760 struct xen_netif_extra_info *gso)
761{
762 if (!gso->u.gso.size) {
763 netdev_err(vif->dev, "GSO size must not be zero.\n");
764 xenvif_fatal_tx_err(vif);
765 return -EINVAL;
766 }
767
768 switch (gso->u.gso.type) {
769 case XEN_NETIF_GSO_TYPE_TCPV4:
770 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
771 break;
772 case XEN_NETIF_GSO_TYPE_TCPV6:
773 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
774 break;
775 default:
776 netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
777 xenvif_fatal_tx_err(vif);
778 return -EINVAL;
779 }
780
781 skb_shinfo(skb)->gso_size = gso->u.gso.size;
782 /* gso_segs will be calculated later */
783
784 return 0;
785}
786
787static int checksum_setup(struct xenvif_queue *queue, struct sk_buff *skb)
788{
789 bool recalculate_partial_csum = false;
790
791 /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
792 * peers can fail to set NETRXF_csum_blank when sending a GSO
793 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
794 * recalculate the partial checksum.
795 */
796 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
797 queue->stats.rx_gso_checksum_fixup++;
798 skb->ip_summed = CHECKSUM_PARTIAL;
799 recalculate_partial_csum = true;
800 }
801
802 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
803 if (skb->ip_summed != CHECKSUM_PARTIAL)
804 return 0;
805
806 return skb_checksum_setup(skb, recalculate_partial_csum);
807}
808
809static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size)
810{
811 u64 now = get_jiffies_64();
812 u64 next_credit = queue->credit_window_start +
813 msecs_to_jiffies(queue->credit_usec / 1000);
814
815 /* Timer could already be pending in rare cases. */
816 if (timer_pending(&queue->credit_timeout)) {
817 queue->rate_limited = true;
818 return true;
819 }
820
821 /* Passed the point where we can replenish credit? */
822 if (time_after_eq64(now, next_credit)) {
823 queue->credit_window_start = now;
824 tx_add_credit(queue);
825 }
826
827 /* Still too big to send right now? Set a callback. */
828 if (size > queue->remaining_credit) {
829 mod_timer(&queue->credit_timeout,
830 next_credit);
831 queue->credit_window_start = next_credit;
832 queue->rate_limited = true;
833
834 return true;
835 }
836
837 return false;
838}
839
840/* No locking is required in xenvif_mcast_add/del() as they are
841 * only ever invoked from NAPI poll. An RCU list is used because
842 * xenvif_mcast_match() is called asynchronously, during start_xmit.
843 */
844
845static int xenvif_mcast_add(struct xenvif *vif, const u8 *addr)
846{
847 struct xenvif_mcast_addr *mcast;
848
849 if (vif->fe_mcast_count == XEN_NETBK_MCAST_MAX) {
850 if (net_ratelimit())
851 netdev_err(vif->dev,
852 "Too many multicast addresses\n");
853 return -ENOSPC;
854 }
855
856 mcast = kzalloc(sizeof(*mcast), GFP_ATOMIC);
857 if (!mcast)
858 return -ENOMEM;
859
860 ether_addr_copy(mcast->addr, addr);
861 list_add_tail_rcu(&mcast->entry, &vif->fe_mcast_addr);
862 vif->fe_mcast_count++;
863
864 return 0;
865}
866
867static void xenvif_mcast_del(struct xenvif *vif, const u8 *addr)
868{
869 struct xenvif_mcast_addr *mcast;
870
871 list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
872 if (ether_addr_equal(addr, mcast->addr)) {
873 --vif->fe_mcast_count;
874 list_del_rcu(&mcast->entry);
875 kfree_rcu(mcast, rcu);
876 break;
877 }
878 }
879}
880
881bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr)
882{
883 struct xenvif_mcast_addr *mcast;
884
885 rcu_read_lock();
886 list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
887 if (ether_addr_equal(addr, mcast->addr)) {
888 rcu_read_unlock();
889 return true;
890 }
891 }
892 rcu_read_unlock();
893
894 return false;
895}
896
897void xenvif_mcast_addr_list_free(struct xenvif *vif)
898{
899 /* No need for locking or RCU here. NAPI poll and TX queue
900 * are stopped.
901 */
902 while (!list_empty(&vif->fe_mcast_addr)) {
903 struct xenvif_mcast_addr *mcast;
904
905 mcast = list_first_entry(&vif->fe_mcast_addr,
906 struct xenvif_mcast_addr,
907 entry);
908 --vif->fe_mcast_count;
909 list_del(&mcast->entry);
910 kfree(mcast);
911 }
912}
913
914static void xenvif_tx_build_gops(struct xenvif_queue *queue,
915 int budget,
916 unsigned *copy_ops,
917 unsigned *map_ops)
918{
919 struct sk_buff *skb, *nskb;
920 int ret;
921 unsigned int frag_overflow;
922
923 while (skb_queue_len(&queue->tx_queue) < budget) {
924 struct xen_netif_tx_request txreq;
925 struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
926 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
927 unsigned int extra_count;
928 RING_IDX idx;
929 int work_to_do;
930 unsigned int data_len;
931
932 if (queue->tx.sring->req_prod - queue->tx.req_cons >
933 XEN_NETIF_TX_RING_SIZE) {
934 netdev_err(queue->vif->dev,
935 "Impossible number of requests. "
936 "req_prod %d, req_cons %d, size %ld\n",
937 queue->tx.sring->req_prod, queue->tx.req_cons,
938 XEN_NETIF_TX_RING_SIZE);
939 xenvif_fatal_tx_err(queue->vif);
940 break;
941 }
942
943 work_to_do = XEN_RING_NR_UNCONSUMED_REQUESTS(&queue->tx);
944 if (!work_to_do)
945 break;
946
947 idx = queue->tx.req_cons;
948 rmb(); /* Ensure that we see the request before we copy it. */
949 RING_COPY_REQUEST(&queue->tx, idx, &txreq);
950
951 /* Credit-based scheduling. */
952 if (txreq.size > queue->remaining_credit &&
953 tx_credit_exceeded(queue, txreq.size))
954 break;
955
956 queue->remaining_credit -= txreq.size;
957
958 work_to_do--;
959 queue->tx.req_cons = ++idx;
960
961 memset(extras, 0, sizeof(extras));
962 extra_count = 0;
963 if (txreq.flags & XEN_NETTXF_extra_info) {
964 work_to_do = xenvif_get_extras(queue, extras,
965 &extra_count,
966 work_to_do);
967 idx = queue->tx.req_cons;
968 if (unlikely(work_to_do < 0))
969 break;
970 }
971
972 if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1].type) {
973 struct xen_netif_extra_info *extra;
974
975 extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1];
976 ret = xenvif_mcast_add(queue->vif, extra->u.mcast.addr);
977
978 make_tx_response(queue, &txreq, extra_count,
979 (ret == 0) ?
980 XEN_NETIF_RSP_OKAY :
981 XEN_NETIF_RSP_ERROR);
982 continue;
983 }
984
985 if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1].type) {
986 struct xen_netif_extra_info *extra;
987
988 extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1];
989 xenvif_mcast_del(queue->vif, extra->u.mcast.addr);
990
991 make_tx_response(queue, &txreq, extra_count,
992 XEN_NETIF_RSP_OKAY);
993 continue;
994 }
995
996 data_len = (txreq.size > XEN_NETBACK_TX_COPY_LEN) ?
997 XEN_NETBACK_TX_COPY_LEN : txreq.size;
998
999 ret = xenvif_count_requests(queue, &txreq, extra_count,
1000 txfrags, work_to_do);
1001
1002 if (unlikely(ret < 0))
1003 break;
1004
1005 idx += ret;
1006
1007 if (unlikely(txreq.size < ETH_HLEN)) {
1008 netdev_dbg(queue->vif->dev,
1009 "Bad packet size: %d\n", txreq.size);
1010 xenvif_tx_err(queue, &txreq, extra_count, idx);
1011 break;
1012 }
1013
1014 /* No crossing a page as the payload mustn't fragment. */
1015 if (unlikely((txreq.offset + txreq.size) > XEN_PAGE_SIZE)) {
1016 netdev_err(queue->vif->dev, "Cross page boundary, txreq.offset: %u, size: %u\n",
1017 txreq.offset, txreq.size);
1018 xenvif_fatal_tx_err(queue->vif);
1019 break;
1020 }
1021
1022 if (ret >= XEN_NETBK_LEGACY_SLOTS_MAX - 1 && data_len < txreq.size)
1023 data_len = txreq.size;
1024
1025 skb = xenvif_alloc_skb(data_len);
1026 if (unlikely(skb == NULL)) {
1027 netdev_dbg(queue->vif->dev,
1028 "Can't allocate a skb in start_xmit.\n");
1029 xenvif_tx_err(queue, &txreq, extra_count, idx);
1030 break;
1031 }
1032
1033 skb_shinfo(skb)->nr_frags = ret;
1034 /* At this point shinfo->nr_frags is in fact the number of
1035 * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
1036 */
1037 frag_overflow = 0;
1038 nskb = NULL;
1039 if (skb_shinfo(skb)->nr_frags > MAX_SKB_FRAGS) {
1040 frag_overflow = skb_shinfo(skb)->nr_frags - MAX_SKB_FRAGS;
1041 BUG_ON(frag_overflow > MAX_SKB_FRAGS);
1042 skb_shinfo(skb)->nr_frags = MAX_SKB_FRAGS;
1043 nskb = xenvif_alloc_skb(0);
1044 if (unlikely(nskb == NULL)) {
1045 skb_shinfo(skb)->nr_frags = 0;
1046 kfree_skb(skb);
1047 xenvif_tx_err(queue, &txreq, extra_count, idx);
1048 if (net_ratelimit())
1049 netdev_err(queue->vif->dev,
1050 "Can't allocate the frag_list skb.\n");
1051 break;
1052 }
1053 }
1054
1055 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1056 struct xen_netif_extra_info *gso;
1057 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1058
1059 if (xenvif_set_skb_gso(queue->vif, skb, gso)) {
1060 /* Failure in xenvif_set_skb_gso is fatal. */
1061 skb_shinfo(skb)->nr_frags = 0;
1062 kfree_skb(skb);
1063 kfree_skb(nskb);
1064 break;
1065 }
1066 }
1067
1068 if (extras[XEN_NETIF_EXTRA_TYPE_HASH - 1].type) {
1069 struct xen_netif_extra_info *extra;
1070 enum pkt_hash_types type = PKT_HASH_TYPE_NONE;
1071
1072 extra = &extras[XEN_NETIF_EXTRA_TYPE_HASH - 1];
1073
1074 switch (extra->u.hash.type) {
1075 case _XEN_NETIF_CTRL_HASH_TYPE_IPV4:
1076 case _XEN_NETIF_CTRL_HASH_TYPE_IPV6:
1077 type = PKT_HASH_TYPE_L3;
1078 break;
1079
1080 case _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP:
1081 case _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP:
1082 type = PKT_HASH_TYPE_L4;
1083 break;
1084
1085 default:
1086 break;
1087 }
1088
1089 if (type != PKT_HASH_TYPE_NONE)
1090 skb_set_hash(skb,
1091 *(u32 *)extra->u.hash.value,
1092 type);
1093 }
1094
1095 xenvif_get_requests(queue, skb, &txreq, txfrags, copy_ops,
1096 map_ops, frag_overflow, nskb, extra_count,
1097 data_len);
1098
1099 __skb_queue_tail(&queue->tx_queue, skb);
1100
1101 queue->tx.req_cons = idx;
1102 }
1103
1104 return;
1105}
1106
1107/* Consolidate skb with a frag_list into a brand new one with local pages on
1108 * frags. Returns 0 or -ENOMEM if can't allocate new pages.
1109 */
1110static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *skb)
1111{
1112 unsigned int offset = skb_headlen(skb);
1113 skb_frag_t frags[MAX_SKB_FRAGS];
1114 int i, f;
1115 struct ubuf_info *uarg;
1116 struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
1117
1118 queue->stats.tx_zerocopy_sent += 2;
1119 queue->stats.tx_frag_overflow++;
1120
1121 xenvif_fill_frags(queue, nskb);
1122 /* Subtract frags size, we will correct it later */
1123 skb->truesize -= skb->data_len;
1124 skb->len += nskb->len;
1125 skb->data_len += nskb->len;
1126
1127 /* create a brand new frags array and coalesce there */
1128 for (i = 0; offset < skb->len; i++) {
1129 struct page *page;
1130 unsigned int len;
1131
1132 BUG_ON(i >= MAX_SKB_FRAGS);
1133 page = alloc_page(GFP_ATOMIC);
1134 if (!page) {
1135 int j;
1136 skb->truesize += skb->data_len;
1137 for (j = 0; j < i; j++)
1138 put_page(skb_frag_page(&frags[j]));
1139 return -ENOMEM;
1140 }
1141
1142 if (offset + PAGE_SIZE < skb->len)
1143 len = PAGE_SIZE;
1144 else
1145 len = skb->len - offset;
1146 if (skb_copy_bits(skb, offset, page_address(page), len))
1147 BUG();
1148
1149 offset += len;
1150 skb_frag_fill_page_desc(&frags[i], page, 0, len);
1151 }
1152
1153 /* Release all the original (foreign) frags. */
1154 for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
1155 skb_frag_unref(skb, f);
1156 uarg = skb_shinfo(skb)->destructor_arg;
1157 /* increase inflight counter to offset decrement in callback */
1158 atomic_inc(&queue->inflight_packets);
1159 uarg->callback(NULL, uarg, true);
1160 skb_shinfo(skb)->destructor_arg = NULL;
1161
1162 /* Fill the skb with the new (local) frags. */
1163 memcpy(skb_shinfo(skb)->frags, frags, i * sizeof(skb_frag_t));
1164 skb_shinfo(skb)->nr_frags = i;
1165 skb->truesize += i * PAGE_SIZE;
1166
1167 return 0;
1168}
1169
1170static int xenvif_tx_submit(struct xenvif_queue *queue)
1171{
1172 struct gnttab_map_grant_ref *gop_map = queue->tx_map_ops;
1173 struct gnttab_copy *gop_copy = queue->tx_copy_ops;
1174 struct sk_buff *skb;
1175 int work_done = 0;
1176
1177 while ((skb = __skb_dequeue(&queue->tx_queue)) != NULL) {
1178 struct xen_netif_tx_request *txp;
1179 u16 pending_idx;
1180
1181 pending_idx = copy_pending_idx(skb, 0);
1182 txp = &queue->pending_tx_info[pending_idx].req;
1183
1184 /* Check the remap error code. */
1185 if (unlikely(xenvif_tx_check_gop(queue, skb, &gop_map, &gop_copy))) {
1186 /* If there was an error, xenvif_tx_check_gop is
1187 * expected to release all the frags which were mapped,
1188 * so kfree_skb shouldn't do it again
1189 */
1190 skb_shinfo(skb)->nr_frags = 0;
1191 if (skb_has_frag_list(skb)) {
1192 struct sk_buff *nskb =
1193 skb_shinfo(skb)->frag_list;
1194 skb_shinfo(nskb)->nr_frags = 0;
1195 }
1196 kfree_skb(skb);
1197 continue;
1198 }
1199
1200 if (txp->flags & XEN_NETTXF_csum_blank)
1201 skb->ip_summed = CHECKSUM_PARTIAL;
1202 else if (txp->flags & XEN_NETTXF_data_validated)
1203 skb->ip_summed = CHECKSUM_UNNECESSARY;
1204
1205 xenvif_fill_frags(queue, skb);
1206
1207 if (unlikely(skb_has_frag_list(skb))) {
1208 struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
1209 xenvif_skb_zerocopy_prepare(queue, nskb);
1210 if (xenvif_handle_frag_list(queue, skb)) {
1211 if (net_ratelimit())
1212 netdev_err(queue->vif->dev,
1213 "Not enough memory to consolidate frag_list!\n");
1214 xenvif_skb_zerocopy_prepare(queue, skb);
1215 kfree_skb(skb);
1216 continue;
1217 }
1218 /* Copied all the bits from the frag list -- free it. */
1219 skb_frag_list_init(skb);
1220 kfree_skb(nskb);
1221 }
1222
1223 skb->dev = queue->vif->dev;
1224 skb->protocol = eth_type_trans(skb, skb->dev);
1225 skb_reset_network_header(skb);
1226
1227 if (checksum_setup(queue, skb)) {
1228 netdev_dbg(queue->vif->dev,
1229 "Can't setup checksum in net_tx_action\n");
1230 /* We have to set this flag to trigger the callback */
1231 if (skb_shinfo(skb)->destructor_arg)
1232 xenvif_skb_zerocopy_prepare(queue, skb);
1233 kfree_skb(skb);
1234 continue;
1235 }
1236
1237 skb_probe_transport_header(skb);
1238
1239 /* If the packet is GSO then we will have just set up the
1240 * transport header offset in checksum_setup so it's now
1241 * straightforward to calculate gso_segs.
1242 */
1243 if (skb_is_gso(skb)) {
1244 int mss, hdrlen;
1245
1246 /* GSO implies having the L4 header. */
1247 WARN_ON_ONCE(!skb_transport_header_was_set(skb));
1248 if (unlikely(!skb_transport_header_was_set(skb))) {
1249 kfree_skb(skb);
1250 continue;
1251 }
1252
1253 mss = skb_shinfo(skb)->gso_size;
1254 hdrlen = skb_tcp_all_headers(skb);
1255
1256 skb_shinfo(skb)->gso_segs =
1257 DIV_ROUND_UP(skb->len - hdrlen, mss);
1258 }
1259
1260 queue->stats.rx_bytes += skb->len;
1261 queue->stats.rx_packets++;
1262
1263 work_done++;
1264
1265 /* Set this flag right before netif_receive_skb, otherwise
1266 * someone might think this packet already left netback, and
1267 * do a skb_copy_ubufs while we are still in control of the
1268 * skb. E.g. the __pskb_pull_tail earlier can do such thing.
1269 */
1270 if (skb_shinfo(skb)->destructor_arg) {
1271 xenvif_skb_zerocopy_prepare(queue, skb);
1272 queue->stats.tx_zerocopy_sent++;
1273 }
1274
1275 netif_receive_skb(skb);
1276 }
1277
1278 return work_done;
1279}
1280
1281void xenvif_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *ubuf_base,
1282 bool zerocopy_success)
1283{
1284 unsigned long flags;
1285 pending_ring_idx_t index;
1286 struct ubuf_info_msgzc *ubuf = uarg_to_msgzc(ubuf_base);
1287 struct xenvif_queue *queue = ubuf_to_queue(ubuf);
1288
1289 /* This is the only place where we grab this lock, to protect callbacks
1290 * from each other.
1291 */
1292 spin_lock_irqsave(&queue->callback_lock, flags);
1293 do {
1294 u16 pending_idx = ubuf->desc;
1295 ubuf = (struct ubuf_info_msgzc *) ubuf->ctx;
1296 BUG_ON(queue->dealloc_prod - queue->dealloc_cons >=
1297 MAX_PENDING_REQS);
1298 index = pending_index(queue->dealloc_prod);
1299 queue->dealloc_ring[index] = pending_idx;
1300 /* Sync with xenvif_tx_dealloc_action:
1301 * insert idx then incr producer.
1302 */
1303 smp_wmb();
1304 queue->dealloc_prod++;
1305 } while (ubuf);
1306 spin_unlock_irqrestore(&queue->callback_lock, flags);
1307
1308 if (likely(zerocopy_success))
1309 queue->stats.tx_zerocopy_success++;
1310 else
1311 queue->stats.tx_zerocopy_fail++;
1312 xenvif_skb_zerocopy_complete(queue);
1313}
1314
1315static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue)
1316{
1317 struct gnttab_unmap_grant_ref *gop;
1318 pending_ring_idx_t dc, dp;
1319 u16 pending_idx, pending_idx_release[MAX_PENDING_REQS];
1320 unsigned int i = 0;
1321
1322 dc = queue->dealloc_cons;
1323 gop = queue->tx_unmap_ops;
1324
1325 /* Free up any grants we have finished using */
1326 do {
1327 dp = queue->dealloc_prod;
1328
1329 /* Ensure we see all indices enqueued by all
1330 * xenvif_zerocopy_callback().
1331 */
1332 smp_rmb();
1333
1334 while (dc != dp) {
1335 BUG_ON(gop - queue->tx_unmap_ops >= MAX_PENDING_REQS);
1336 pending_idx =
1337 queue->dealloc_ring[pending_index(dc++)];
1338
1339 pending_idx_release[gop - queue->tx_unmap_ops] =
1340 pending_idx;
1341 queue->pages_to_unmap[gop - queue->tx_unmap_ops] =
1342 queue->mmap_pages[pending_idx];
1343 gnttab_set_unmap_op(gop,
1344 idx_to_kaddr(queue, pending_idx),
1345 GNTMAP_host_map,
1346 queue->grant_tx_handle[pending_idx]);
1347 xenvif_grant_handle_reset(queue, pending_idx);
1348 ++gop;
1349 }
1350
1351 } while (dp != queue->dealloc_prod);
1352
1353 queue->dealloc_cons = dc;
1354
1355 if (gop - queue->tx_unmap_ops > 0) {
1356 int ret;
1357 ret = gnttab_unmap_refs(queue->tx_unmap_ops,
1358 NULL,
1359 queue->pages_to_unmap,
1360 gop - queue->tx_unmap_ops);
1361 if (ret) {
1362 netdev_err(queue->vif->dev, "Unmap fail: nr_ops %tu ret %d\n",
1363 gop - queue->tx_unmap_ops, ret);
1364 for (i = 0; i < gop - queue->tx_unmap_ops; ++i) {
1365 if (gop[i].status != GNTST_okay)
1366 netdev_err(queue->vif->dev,
1367 " host_addr: 0x%llx handle: 0x%x status: %d\n",
1368 gop[i].host_addr,
1369 gop[i].handle,
1370 gop[i].status);
1371 }
1372 BUG();
1373 }
1374 }
1375
1376 for (i = 0; i < gop - queue->tx_unmap_ops; ++i)
1377 xenvif_idx_release(queue, pending_idx_release[i],
1378 XEN_NETIF_RSP_OKAY);
1379}
1380
1381
1382/* Called after netfront has transmitted */
1383int xenvif_tx_action(struct xenvif_queue *queue, int budget)
1384{
1385 unsigned nr_mops = 0, nr_cops = 0;
1386 int work_done, ret;
1387
1388 if (unlikely(!tx_work_todo(queue)))
1389 return 0;
1390
1391 xenvif_tx_build_gops(queue, budget, &nr_cops, &nr_mops);
1392
1393 if (nr_cops == 0)
1394 return 0;
1395
1396 gnttab_batch_copy(queue->tx_copy_ops, nr_cops);
1397 if (nr_mops != 0) {
1398 ret = gnttab_map_refs(queue->tx_map_ops,
1399 NULL,
1400 queue->pages_to_map,
1401 nr_mops);
1402 if (ret) {
1403 unsigned int i;
1404
1405 netdev_err(queue->vif->dev, "Map fail: nr %u ret %d\n",
1406 nr_mops, ret);
1407 for (i = 0; i < nr_mops; ++i)
1408 WARN_ON_ONCE(queue->tx_map_ops[i].status ==
1409 GNTST_okay);
1410 }
1411 }
1412
1413 work_done = xenvif_tx_submit(queue);
1414
1415 return work_done;
1416}
1417
1418static void _make_tx_response(struct xenvif_queue *queue,
1419 const struct xen_netif_tx_request *txp,
1420 unsigned int extra_count,
1421 s8 status)
1422{
1423 RING_IDX i = queue->tx.rsp_prod_pvt;
1424 struct xen_netif_tx_response *resp;
1425
1426 resp = RING_GET_RESPONSE(&queue->tx, i);
1427 resp->id = txp->id;
1428 resp->status = status;
1429
1430 while (extra_count-- != 0)
1431 RING_GET_RESPONSE(&queue->tx, ++i)->status = XEN_NETIF_RSP_NULL;
1432
1433 queue->tx.rsp_prod_pvt = ++i;
1434}
1435
1436static void push_tx_responses(struct xenvif_queue *queue)
1437{
1438 int notify;
1439
1440 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->tx, notify);
1441 if (notify)
1442 notify_remote_via_irq(queue->tx_irq);
1443}
1444
1445static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
1446 s8 status)
1447{
1448 struct pending_tx_info *pending_tx_info;
1449 pending_ring_idx_t index;
1450 unsigned long flags;
1451
1452 pending_tx_info = &queue->pending_tx_info[pending_idx];
1453
1454 spin_lock_irqsave(&queue->response_lock, flags);
1455
1456 _make_tx_response(queue, &pending_tx_info->req,
1457 pending_tx_info->extra_count, status);
1458
1459 /* Release the pending index before pusing the Tx response so
1460 * its available before a new Tx request is pushed by the
1461 * frontend.
1462 */
1463 index = pending_index(queue->pending_prod++);
1464 queue->pending_ring[index] = pending_idx;
1465
1466 push_tx_responses(queue);
1467
1468 spin_unlock_irqrestore(&queue->response_lock, flags);
1469}
1470
1471static void make_tx_response(struct xenvif_queue *queue,
1472 const struct xen_netif_tx_request *txp,
1473 unsigned int extra_count,
1474 s8 status)
1475{
1476 unsigned long flags;
1477
1478 spin_lock_irqsave(&queue->response_lock, flags);
1479
1480 _make_tx_response(queue, txp, extra_count, status);
1481 push_tx_responses(queue);
1482
1483 spin_unlock_irqrestore(&queue->response_lock, flags);
1484}
1485
1486static void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx)
1487{
1488 int ret;
1489 struct gnttab_unmap_grant_ref tx_unmap_op;
1490
1491 gnttab_set_unmap_op(&tx_unmap_op,
1492 idx_to_kaddr(queue, pending_idx),
1493 GNTMAP_host_map,
1494 queue->grant_tx_handle[pending_idx]);
1495 xenvif_grant_handle_reset(queue, pending_idx);
1496
1497 ret = gnttab_unmap_refs(&tx_unmap_op, NULL,
1498 &queue->mmap_pages[pending_idx], 1);
1499 if (ret) {
1500 netdev_err(queue->vif->dev,
1501 "Unmap fail: ret: %d pending_idx: %d host_addr: %llx handle: 0x%x status: %d\n",
1502 ret,
1503 pending_idx,
1504 tx_unmap_op.host_addr,
1505 tx_unmap_op.handle,
1506 tx_unmap_op.status);
1507 BUG();
1508 }
1509}
1510
1511static inline int tx_work_todo(struct xenvif_queue *queue)
1512{
1513 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&queue->tx)))
1514 return 1;
1515
1516 return 0;
1517}
1518
1519static inline bool tx_dealloc_work_todo(struct xenvif_queue *queue)
1520{
1521 return queue->dealloc_cons != queue->dealloc_prod;
1522}
1523
1524void xenvif_unmap_frontend_data_rings(struct xenvif_queue *queue)
1525{
1526 if (queue->tx.sring)
1527 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
1528 queue->tx.sring);
1529 if (queue->rx.sring)
1530 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
1531 queue->rx.sring);
1532}
1533
1534int xenvif_map_frontend_data_rings(struct xenvif_queue *queue,
1535 grant_ref_t tx_ring_ref,
1536 grant_ref_t rx_ring_ref)
1537{
1538 void *addr;
1539 struct xen_netif_tx_sring *txs;
1540 struct xen_netif_rx_sring *rxs;
1541 RING_IDX rsp_prod, req_prod;
1542 int err;
1543
1544 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
1545 &tx_ring_ref, 1, &addr);
1546 if (err)
1547 goto err;
1548
1549 txs = (struct xen_netif_tx_sring *)addr;
1550 rsp_prod = READ_ONCE(txs->rsp_prod);
1551 req_prod = READ_ONCE(txs->req_prod);
1552
1553 BACK_RING_ATTACH(&queue->tx, txs, rsp_prod, XEN_PAGE_SIZE);
1554
1555 err = -EIO;
1556 if (req_prod - rsp_prod > RING_SIZE(&queue->tx))
1557 goto err;
1558
1559 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
1560 &rx_ring_ref, 1, &addr);
1561 if (err)
1562 goto err;
1563
1564 rxs = (struct xen_netif_rx_sring *)addr;
1565 rsp_prod = READ_ONCE(rxs->rsp_prod);
1566 req_prod = READ_ONCE(rxs->req_prod);
1567
1568 BACK_RING_ATTACH(&queue->rx, rxs, rsp_prod, XEN_PAGE_SIZE);
1569
1570 err = -EIO;
1571 if (req_prod - rsp_prod > RING_SIZE(&queue->rx))
1572 goto err;
1573
1574 return 0;
1575
1576err:
1577 xenvif_unmap_frontend_data_rings(queue);
1578 return err;
1579}
1580
1581static bool xenvif_dealloc_kthread_should_stop(struct xenvif_queue *queue)
1582{
1583 /* Dealloc thread must remain running until all inflight
1584 * packets complete.
1585 */
1586 return kthread_should_stop() &&
1587 !atomic_read(&queue->inflight_packets);
1588}
1589
1590int xenvif_dealloc_kthread(void *data)
1591{
1592 struct xenvif_queue *queue = data;
1593
1594 for (;;) {
1595 wait_event_interruptible(queue->dealloc_wq,
1596 tx_dealloc_work_todo(queue) ||
1597 xenvif_dealloc_kthread_should_stop(queue));
1598 if (xenvif_dealloc_kthread_should_stop(queue))
1599 break;
1600
1601 xenvif_tx_dealloc_action(queue);
1602 cond_resched();
1603 }
1604
1605 /* Unmap anything remaining*/
1606 if (tx_dealloc_work_todo(queue))
1607 xenvif_tx_dealloc_action(queue);
1608
1609 return 0;
1610}
1611
1612static void make_ctrl_response(struct xenvif *vif,
1613 const struct xen_netif_ctrl_request *req,
1614 u32 status, u32 data)
1615{
1616 RING_IDX idx = vif->ctrl.rsp_prod_pvt;
1617 struct xen_netif_ctrl_response rsp = {
1618 .id = req->id,
1619 .type = req->type,
1620 .status = status,
1621 .data = data,
1622 };
1623
1624 *RING_GET_RESPONSE(&vif->ctrl, idx) = rsp;
1625 vif->ctrl.rsp_prod_pvt = ++idx;
1626}
1627
1628static void push_ctrl_response(struct xenvif *vif)
1629{
1630 int notify;
1631
1632 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->ctrl, notify);
1633 if (notify)
1634 notify_remote_via_irq(vif->ctrl_irq);
1635}
1636
1637static void process_ctrl_request(struct xenvif *vif,
1638 const struct xen_netif_ctrl_request *req)
1639{
1640 u32 status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED;
1641 u32 data = 0;
1642
1643 switch (req->type) {
1644 case XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM:
1645 status = xenvif_set_hash_alg(vif, req->data[0]);
1646 break;
1647
1648 case XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS:
1649 status = xenvif_get_hash_flags(vif, &data);
1650 break;
1651
1652 case XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS:
1653 status = xenvif_set_hash_flags(vif, req->data[0]);
1654 break;
1655
1656 case XEN_NETIF_CTRL_TYPE_SET_HASH_KEY:
1657 status = xenvif_set_hash_key(vif, req->data[0],
1658 req->data[1]);
1659 break;
1660
1661 case XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE:
1662 status = XEN_NETIF_CTRL_STATUS_SUCCESS;
1663 data = XEN_NETBK_MAX_HASH_MAPPING_SIZE;
1664 break;
1665
1666 case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE:
1667 status = xenvif_set_hash_mapping_size(vif,
1668 req->data[0]);
1669 break;
1670
1671 case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING:
1672 status = xenvif_set_hash_mapping(vif, req->data[0],
1673 req->data[1],
1674 req->data[2]);
1675 break;
1676
1677 default:
1678 break;
1679 }
1680
1681 make_ctrl_response(vif, req, status, data);
1682 push_ctrl_response(vif);
1683}
1684
1685static void xenvif_ctrl_action(struct xenvif *vif)
1686{
1687 for (;;) {
1688 RING_IDX req_prod, req_cons;
1689
1690 req_prod = vif->ctrl.sring->req_prod;
1691 req_cons = vif->ctrl.req_cons;
1692
1693 /* Make sure we can see requests before we process them. */
1694 rmb();
1695
1696 if (req_cons == req_prod)
1697 break;
1698
1699 while (req_cons != req_prod) {
1700 struct xen_netif_ctrl_request req;
1701
1702 RING_COPY_REQUEST(&vif->ctrl, req_cons, &req);
1703 req_cons++;
1704
1705 process_ctrl_request(vif, &req);
1706 }
1707
1708 vif->ctrl.req_cons = req_cons;
1709 vif->ctrl.sring->req_event = req_cons + 1;
1710 }
1711}
1712
1713static bool xenvif_ctrl_work_todo(struct xenvif *vif)
1714{
1715 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->ctrl)))
1716 return true;
1717
1718 return false;
1719}
1720
1721irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data)
1722{
1723 struct xenvif *vif = data;
1724 unsigned int eoi_flag = XEN_EOI_FLAG_SPURIOUS;
1725
1726 while (xenvif_ctrl_work_todo(vif)) {
1727 xenvif_ctrl_action(vif);
1728 eoi_flag = 0;
1729 }
1730
1731 xen_irq_lateeoi(irq, eoi_flag);
1732
1733 return IRQ_HANDLED;
1734}
1735
1736static int __init netback_init(void)
1737{
1738 int rc = 0;
1739
1740 if (!xen_domain())
1741 return -ENODEV;
1742
1743 /* Allow as many queues as there are CPUs but max. 8 if user has not
1744 * specified a value.
1745 */
1746 if (xenvif_max_queues == 0)
1747 xenvif_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
1748 num_online_cpus());
1749
1750 if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
1751 pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
1752 fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX);
1753 fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX;
1754 }
1755
1756 rc = xenvif_xenbus_init();
1757 if (rc)
1758 goto failed_init;
1759
1760#ifdef CONFIG_DEBUG_FS
1761 xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL);
1762#endif /* CONFIG_DEBUG_FS */
1763
1764 return 0;
1765
1766failed_init:
1767 return rc;
1768}
1769
1770module_init(netback_init);
1771
1772static void __exit netback_fini(void)
1773{
1774#ifdef CONFIG_DEBUG_FS
1775 debugfs_remove_recursive(xen_netback_dbg_root);
1776#endif /* CONFIG_DEBUG_FS */
1777 xenvif_xenbus_fini();
1778}
1779module_exit(netback_fini);
1780
1781MODULE_DESCRIPTION("Xen backend network device module");
1782MODULE_LICENSE("Dual BSD/GPL");
1783MODULE_ALIAS("xen-backend:vif");
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 */
55bool separate_tx_rx_irq = true;
56module_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 */
61unsigned int rx_drain_timeout_msecs = 10000;
62module_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 */
67unsigned int rx_stall_timeout_msecs = 60000;
68module_param(rx_stall_timeout_msecs, uint, 0444);
69
70#define MAX_QUEUES_DEFAULT 8
71unsigned int xenvif_max_queues;
72module_param_named(max_queues, xenvif_max_queues, uint, 0644);
73MODULE_PARM_DESC(max_queues,
74 "Maximum number of queues per virtual interface");
75
76/*
77 * This is the maximum slots a skb can have. If a guest sends a skb
78 * which exceeds this limit it is considered malicious.
79 */
80#define FATAL_SKB_SLOTS_DEFAULT 20
81static unsigned int fatal_skb_slots = FATAL_SKB_SLOTS_DEFAULT;
82module_param(fatal_skb_slots, uint, 0444);
83
84/* The amount to copy out of the first guest Tx slot into the skb's
85 * linear area. If the first slot has more data, it will be mapped
86 * and put into the first frag.
87 *
88 * This is sized to avoid pulling headers from the frags for most
89 * TCP/IP packets.
90 */
91#define XEN_NETBACK_TX_COPY_LEN 128
92
93/* This is the maximum number of flows in the hash cache. */
94#define XENVIF_HASH_CACHE_SIZE_DEFAULT 64
95unsigned int xenvif_hash_cache_size = XENVIF_HASH_CACHE_SIZE_DEFAULT;
96module_param_named(hash_cache_size, xenvif_hash_cache_size, uint, 0644);
97MODULE_PARM_DESC(hash_cache_size, "Number of flows in the hash cache");
98
99/* The module parameter tells that we have to put data
100 * for xen-netfront with the XDP_PACKET_HEADROOM offset
101 * needed for XDP processing
102 */
103bool provides_xdp_headroom = true;
104module_param(provides_xdp_headroom, bool, 0644);
105
106static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
107 u8 status);
108
109static void make_tx_response(struct xenvif_queue *queue,
110 struct xen_netif_tx_request *txp,
111 unsigned int extra_count,
112 s8 st);
113static void push_tx_responses(struct xenvif_queue *queue);
114
115static void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx);
116
117static inline int tx_work_todo(struct xenvif_queue *queue);
118
119static inline unsigned long idx_to_pfn(struct xenvif_queue *queue,
120 u16 idx)
121{
122 return page_to_pfn(queue->mmap_pages[idx]);
123}
124
125static inline unsigned long idx_to_kaddr(struct xenvif_queue *queue,
126 u16 idx)
127{
128 return (unsigned long)pfn_to_kaddr(idx_to_pfn(queue, idx));
129}
130
131#define callback_param(vif, pending_idx) \
132 (vif->pending_tx_info[pending_idx].callback_struct)
133
134/* Find the containing VIF's structure from a pointer in pending_tx_info array
135 */
136static inline struct xenvif_queue *ubuf_to_queue(const struct ubuf_info_msgzc *ubuf)
137{
138 u16 pending_idx = ubuf->desc;
139 struct pending_tx_info *temp =
140 container_of(ubuf, struct pending_tx_info, callback_struct);
141 return container_of(temp - pending_idx,
142 struct xenvif_queue,
143 pending_tx_info[0]);
144}
145
146static u16 frag_get_pending_idx(skb_frag_t *frag)
147{
148 return (u16)skb_frag_off(frag);
149}
150
151static void frag_set_pending_idx(skb_frag_t *frag, u16 pending_idx)
152{
153 skb_frag_off_set(frag, pending_idx);
154}
155
156static inline pending_ring_idx_t pending_index(unsigned i)
157{
158 return i & (MAX_PENDING_REQS-1);
159}
160
161void xenvif_kick_thread(struct xenvif_queue *queue)
162{
163 wake_up(&queue->wq);
164}
165
166void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue)
167{
168 int more_to_do;
169
170 RING_FINAL_CHECK_FOR_REQUESTS(&queue->tx, more_to_do);
171
172 if (more_to_do)
173 napi_schedule(&queue->napi);
174 else if (atomic_fetch_andnot(NETBK_TX_EOI | NETBK_COMMON_EOI,
175 &queue->eoi_pending) &
176 (NETBK_TX_EOI | NETBK_COMMON_EOI))
177 xen_irq_lateeoi(queue->tx_irq, 0);
178}
179
180static void tx_add_credit(struct xenvif_queue *queue)
181{
182 unsigned long max_burst, max_credit;
183
184 /*
185 * Allow a burst big enough to transmit a jumbo packet of up to 128kB.
186 * Otherwise the interface can seize up due to insufficient credit.
187 */
188 max_burst = max(131072UL, queue->credit_bytes);
189
190 /* Take care that adding a new chunk of credit doesn't wrap to zero. */
191 max_credit = queue->remaining_credit + queue->credit_bytes;
192 if (max_credit < queue->remaining_credit)
193 max_credit = ULONG_MAX; /* wrapped: clamp to ULONG_MAX */
194
195 queue->remaining_credit = min(max_credit, max_burst);
196 queue->rate_limited = false;
197}
198
199void xenvif_tx_credit_callback(struct timer_list *t)
200{
201 struct xenvif_queue *queue = from_timer(queue, t, credit_timeout);
202 tx_add_credit(queue);
203 xenvif_napi_schedule_or_enable_events(queue);
204}
205
206static void xenvif_tx_err(struct xenvif_queue *queue,
207 struct xen_netif_tx_request *txp,
208 unsigned int extra_count, RING_IDX end)
209{
210 RING_IDX cons = queue->tx.req_cons;
211 unsigned long flags;
212
213 do {
214 spin_lock_irqsave(&queue->response_lock, flags);
215 make_tx_response(queue, txp, extra_count, XEN_NETIF_RSP_ERROR);
216 push_tx_responses(queue);
217 spin_unlock_irqrestore(&queue->response_lock, flags);
218 if (cons == end)
219 break;
220 RING_COPY_REQUEST(&queue->tx, cons++, txp);
221 extra_count = 0; /* only the first frag can have extras */
222 } while (1);
223 queue->tx.req_cons = cons;
224}
225
226static void xenvif_fatal_tx_err(struct xenvif *vif)
227{
228 netdev_err(vif->dev, "fatal error; disabling device\n");
229 vif->disabled = true;
230 /* Disable the vif from queue 0's kthread */
231 if (vif->num_queues)
232 xenvif_kick_thread(&vif->queues[0]);
233}
234
235static int xenvif_count_requests(struct xenvif_queue *queue,
236 struct xen_netif_tx_request *first,
237 unsigned int extra_count,
238 struct xen_netif_tx_request *txp,
239 int work_to_do)
240{
241 RING_IDX cons = queue->tx.req_cons;
242 int slots = 0;
243 int drop_err = 0;
244 int more_data;
245
246 if (!(first->flags & XEN_NETTXF_more_data))
247 return 0;
248
249 do {
250 struct xen_netif_tx_request dropped_tx = { 0 };
251
252 if (slots >= work_to_do) {
253 netdev_err(queue->vif->dev,
254 "Asked for %d slots but exceeds this limit\n",
255 work_to_do);
256 xenvif_fatal_tx_err(queue->vif);
257 return -ENODATA;
258 }
259
260 /* This guest is really using too many slots and
261 * considered malicious.
262 */
263 if (unlikely(slots >= fatal_skb_slots)) {
264 netdev_err(queue->vif->dev,
265 "Malicious frontend using %d slots, threshold %u\n",
266 slots, fatal_skb_slots);
267 xenvif_fatal_tx_err(queue->vif);
268 return -E2BIG;
269 }
270
271 /* Xen network protocol had implicit dependency on
272 * MAX_SKB_FRAGS. XEN_NETBK_LEGACY_SLOTS_MAX is set to
273 * the historical MAX_SKB_FRAGS value 18 to honor the
274 * same behavior as before. Any packet using more than
275 * 18 slots but less than fatal_skb_slots slots is
276 * dropped
277 */
278 if (!drop_err && slots >= XEN_NETBK_LEGACY_SLOTS_MAX) {
279 if (net_ratelimit())
280 netdev_dbg(queue->vif->dev,
281 "Too many slots (%d) exceeding limit (%d), dropping packet\n",
282 slots, XEN_NETBK_LEGACY_SLOTS_MAX);
283 drop_err = -E2BIG;
284 }
285
286 if (drop_err)
287 txp = &dropped_tx;
288
289 RING_COPY_REQUEST(&queue->tx, cons + slots, txp);
290
291 /* If the guest submitted a frame >= 64 KiB then
292 * first->size overflowed and following slots will
293 * appear to be larger than the frame.
294 *
295 * This cannot be fatal error as there are buggy
296 * frontends that do this.
297 *
298 * Consume all slots and drop the packet.
299 */
300 if (!drop_err && txp->size > first->size) {
301 if (net_ratelimit())
302 netdev_dbg(queue->vif->dev,
303 "Invalid tx request, slot size %u > remaining size %u\n",
304 txp->size, first->size);
305 drop_err = -EIO;
306 }
307
308 first->size -= txp->size;
309 slots++;
310
311 if (unlikely((txp->offset + txp->size) > XEN_PAGE_SIZE)) {
312 netdev_err(queue->vif->dev, "Cross page boundary, txp->offset: %u, size: %u\n",
313 txp->offset, txp->size);
314 xenvif_fatal_tx_err(queue->vif);
315 return -EINVAL;
316 }
317
318 more_data = txp->flags & XEN_NETTXF_more_data;
319
320 if (!drop_err)
321 txp++;
322
323 } while (more_data);
324
325 if (drop_err) {
326 xenvif_tx_err(queue, first, extra_count, cons + slots);
327 return drop_err;
328 }
329
330 return slots;
331}
332
333
334struct xenvif_tx_cb {
335 u16 copy_pending_idx[XEN_NETBK_LEGACY_SLOTS_MAX + 1];
336 u8 copy_count;
337};
338
339#define XENVIF_TX_CB(skb) ((struct xenvif_tx_cb *)(skb)->cb)
340#define copy_pending_idx(skb, i) (XENVIF_TX_CB(skb)->copy_pending_idx[i])
341#define copy_count(skb) (XENVIF_TX_CB(skb)->copy_count)
342
343static inline void xenvif_tx_create_map_op(struct xenvif_queue *queue,
344 u16 pending_idx,
345 struct xen_netif_tx_request *txp,
346 unsigned int extra_count,
347 struct gnttab_map_grant_ref *mop)
348{
349 queue->pages_to_map[mop-queue->tx_map_ops] = queue->mmap_pages[pending_idx];
350 gnttab_set_map_op(mop, idx_to_kaddr(queue, pending_idx),
351 GNTMAP_host_map | GNTMAP_readonly,
352 txp->gref, queue->vif->domid);
353
354 memcpy(&queue->pending_tx_info[pending_idx].req, txp,
355 sizeof(*txp));
356 queue->pending_tx_info[pending_idx].extra_count = extra_count;
357}
358
359static inline struct sk_buff *xenvif_alloc_skb(unsigned int size)
360{
361 struct sk_buff *skb =
362 alloc_skb(size + NET_SKB_PAD + NET_IP_ALIGN,
363 GFP_ATOMIC | __GFP_NOWARN);
364 if (unlikely(skb == NULL))
365 return NULL;
366
367 /* Packets passed to netif_rx() must have some headroom. */
368 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
369
370 /* Initialize it here to avoid later surprises */
371 skb_shinfo(skb)->destructor_arg = NULL;
372
373 return skb;
374}
375
376static void xenvif_get_requests(struct xenvif_queue *queue,
377 struct sk_buff *skb,
378 struct xen_netif_tx_request *first,
379 struct xen_netif_tx_request *txfrags,
380 unsigned *copy_ops,
381 unsigned *map_ops,
382 unsigned int frag_overflow,
383 struct sk_buff *nskb,
384 unsigned int extra_count,
385 unsigned int data_len)
386{
387 struct skb_shared_info *shinfo = skb_shinfo(skb);
388 skb_frag_t *frags = shinfo->frags;
389 u16 pending_idx;
390 pending_ring_idx_t index;
391 unsigned int nr_slots;
392 struct gnttab_copy *cop = queue->tx_copy_ops + *copy_ops;
393 struct gnttab_map_grant_ref *gop = queue->tx_map_ops + *map_ops;
394 struct xen_netif_tx_request *txp = first;
395
396 nr_slots = shinfo->nr_frags + 1;
397
398 copy_count(skb) = 0;
399
400 /* Create copy ops for exactly data_len bytes into the skb head. */
401 __skb_put(skb, data_len);
402 while (data_len > 0) {
403 int amount = data_len > txp->size ? txp->size : data_len;
404
405 cop->source.u.ref = txp->gref;
406 cop->source.domid = queue->vif->domid;
407 cop->source.offset = txp->offset;
408
409 cop->dest.domid = DOMID_SELF;
410 cop->dest.offset = (offset_in_page(skb->data +
411 skb_headlen(skb) -
412 data_len)) & ~XEN_PAGE_MASK;
413 cop->dest.u.gmfn = virt_to_gfn(skb->data + skb_headlen(skb)
414 - data_len);
415
416 cop->len = amount;
417 cop->flags = GNTCOPY_source_gref;
418
419 index = pending_index(queue->pending_cons);
420 pending_idx = queue->pending_ring[index];
421 callback_param(queue, pending_idx).ctx = NULL;
422 copy_pending_idx(skb, copy_count(skb)) = pending_idx;
423 copy_count(skb)++;
424
425 cop++;
426 data_len -= amount;
427
428 if (amount == txp->size) {
429 /* The copy op covered the full tx_request */
430
431 memcpy(&queue->pending_tx_info[pending_idx].req,
432 txp, sizeof(*txp));
433 queue->pending_tx_info[pending_idx].extra_count =
434 (txp == first) ? extra_count : 0;
435
436 if (txp == first)
437 txp = txfrags;
438 else
439 txp++;
440 queue->pending_cons++;
441 nr_slots--;
442 } else {
443 /* The copy op partially covered the tx_request.
444 * The remainder will be mapped.
445 */
446 txp->offset += amount;
447 txp->size -= amount;
448 }
449 }
450
451 for (shinfo->nr_frags = 0; shinfo->nr_frags < nr_slots;
452 shinfo->nr_frags++, gop++) {
453 index = pending_index(queue->pending_cons++);
454 pending_idx = queue->pending_ring[index];
455 xenvif_tx_create_map_op(queue, pending_idx, txp,
456 txp == first ? extra_count : 0, gop);
457 frag_set_pending_idx(&frags[shinfo->nr_frags], pending_idx);
458
459 if (txp == first)
460 txp = txfrags;
461 else
462 txp++;
463 }
464
465 if (frag_overflow) {
466
467 shinfo = skb_shinfo(nskb);
468 frags = shinfo->frags;
469
470 for (shinfo->nr_frags = 0; shinfo->nr_frags < frag_overflow;
471 shinfo->nr_frags++, txp++, gop++) {
472 index = pending_index(queue->pending_cons++);
473 pending_idx = queue->pending_ring[index];
474 xenvif_tx_create_map_op(queue, pending_idx, txp, 0,
475 gop);
476 frag_set_pending_idx(&frags[shinfo->nr_frags],
477 pending_idx);
478 }
479
480 skb_shinfo(skb)->frag_list = nskb;
481 }
482
483 (*copy_ops) = cop - queue->tx_copy_ops;
484 (*map_ops) = gop - queue->tx_map_ops;
485}
486
487static inline void xenvif_grant_handle_set(struct xenvif_queue *queue,
488 u16 pending_idx,
489 grant_handle_t handle)
490{
491 if (unlikely(queue->grant_tx_handle[pending_idx] !=
492 NETBACK_INVALID_HANDLE)) {
493 netdev_err(queue->vif->dev,
494 "Trying to overwrite active handle! pending_idx: 0x%x\n",
495 pending_idx);
496 BUG();
497 }
498 queue->grant_tx_handle[pending_idx] = handle;
499}
500
501static inline void xenvif_grant_handle_reset(struct xenvif_queue *queue,
502 u16 pending_idx)
503{
504 if (unlikely(queue->grant_tx_handle[pending_idx] ==
505 NETBACK_INVALID_HANDLE)) {
506 netdev_err(queue->vif->dev,
507 "Trying to unmap invalid handle! pending_idx: 0x%x\n",
508 pending_idx);
509 BUG();
510 }
511 queue->grant_tx_handle[pending_idx] = NETBACK_INVALID_HANDLE;
512}
513
514static int xenvif_tx_check_gop(struct xenvif_queue *queue,
515 struct sk_buff *skb,
516 struct gnttab_map_grant_ref **gopp_map,
517 struct gnttab_copy **gopp_copy)
518{
519 struct gnttab_map_grant_ref *gop_map = *gopp_map;
520 u16 pending_idx;
521 /* This always points to the shinfo of the skb being checked, which
522 * could be either the first or the one on the frag_list
523 */
524 struct skb_shared_info *shinfo = skb_shinfo(skb);
525 /* If this is non-NULL, we are currently checking the frag_list skb, and
526 * this points to the shinfo of the first one
527 */
528 struct skb_shared_info *first_shinfo = NULL;
529 int nr_frags = shinfo->nr_frags;
530 const bool sharedslot = nr_frags &&
531 frag_get_pending_idx(&shinfo->frags[0]) ==
532 copy_pending_idx(skb, copy_count(skb) - 1);
533 int i, err = 0;
534
535 for (i = 0; i < copy_count(skb); i++) {
536 int newerr;
537
538 /* Check status of header. */
539 pending_idx = copy_pending_idx(skb, i);
540
541 newerr = (*gopp_copy)->status;
542 if (likely(!newerr)) {
543 /* The first frag might still have this slot mapped */
544 if (i < copy_count(skb) - 1 || !sharedslot)
545 xenvif_idx_release(queue, pending_idx,
546 XEN_NETIF_RSP_OKAY);
547 } else {
548 err = newerr;
549 if (net_ratelimit())
550 netdev_dbg(queue->vif->dev,
551 "Grant copy of header failed! status: %d pending_idx: %u ref: %u\n",
552 (*gopp_copy)->status,
553 pending_idx,
554 (*gopp_copy)->source.u.ref);
555 /* The first frag might still have this slot mapped */
556 if (i < copy_count(skb) - 1 || !sharedslot)
557 xenvif_idx_release(queue, pending_idx,
558 XEN_NETIF_RSP_ERROR);
559 }
560 (*gopp_copy)++;
561 }
562
563check_frags:
564 for (i = 0; i < nr_frags; i++, gop_map++) {
565 int j, newerr;
566
567 pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
568
569 /* Check error status: if okay then remember grant handle. */
570 newerr = gop_map->status;
571
572 if (likely(!newerr)) {
573 xenvif_grant_handle_set(queue,
574 pending_idx,
575 gop_map->handle);
576 /* Had a previous error? Invalidate this fragment. */
577 if (unlikely(err)) {
578 xenvif_idx_unmap(queue, pending_idx);
579 /* If the mapping of the first frag was OK, but
580 * the header's copy failed, and they are
581 * sharing a slot, send an error
582 */
583 if (i == 0 && !first_shinfo && sharedslot)
584 xenvif_idx_release(queue, pending_idx,
585 XEN_NETIF_RSP_ERROR);
586 else
587 xenvif_idx_release(queue, pending_idx,
588 XEN_NETIF_RSP_OKAY);
589 }
590 continue;
591 }
592
593 /* Error on this fragment: respond to client with an error. */
594 if (net_ratelimit())
595 netdev_dbg(queue->vif->dev,
596 "Grant map of %d. frag failed! status: %d pending_idx: %u ref: %u\n",
597 i,
598 gop_map->status,
599 pending_idx,
600 gop_map->ref);
601
602 xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_ERROR);
603
604 /* Not the first error? Preceding frags already invalidated. */
605 if (err)
606 continue;
607
608 /* Invalidate preceding fragments of this skb. */
609 for (j = 0; j < i; j++) {
610 pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
611 xenvif_idx_unmap(queue, pending_idx);
612 xenvif_idx_release(queue, pending_idx,
613 XEN_NETIF_RSP_OKAY);
614 }
615
616 /* And if we found the error while checking the frag_list, unmap
617 * the first skb's frags
618 */
619 if (first_shinfo) {
620 for (j = 0; j < first_shinfo->nr_frags; j++) {
621 pending_idx = frag_get_pending_idx(&first_shinfo->frags[j]);
622 xenvif_idx_unmap(queue, pending_idx);
623 xenvif_idx_release(queue, pending_idx,
624 XEN_NETIF_RSP_OKAY);
625 }
626 }
627
628 /* Remember the error: invalidate all subsequent fragments. */
629 err = newerr;
630 }
631
632 if (skb_has_frag_list(skb) && !first_shinfo) {
633 first_shinfo = shinfo;
634 shinfo = skb_shinfo(shinfo->frag_list);
635 nr_frags = shinfo->nr_frags;
636
637 goto check_frags;
638 }
639
640 *gopp_map = gop_map;
641 return err;
642}
643
644static void xenvif_fill_frags(struct xenvif_queue *queue, struct sk_buff *skb)
645{
646 struct skb_shared_info *shinfo = skb_shinfo(skb);
647 int nr_frags = shinfo->nr_frags;
648 int i;
649 u16 prev_pending_idx = INVALID_PENDING_IDX;
650
651 for (i = 0; i < nr_frags; i++) {
652 skb_frag_t *frag = shinfo->frags + i;
653 struct xen_netif_tx_request *txp;
654 struct page *page;
655 u16 pending_idx;
656
657 pending_idx = frag_get_pending_idx(frag);
658
659 /* If this is not the first frag, chain it to the previous*/
660 if (prev_pending_idx == INVALID_PENDING_IDX)
661 skb_shinfo(skb)->destructor_arg =
662 &callback_param(queue, pending_idx);
663 else
664 callback_param(queue, prev_pending_idx).ctx =
665 &callback_param(queue, pending_idx);
666
667 callback_param(queue, pending_idx).ctx = NULL;
668 prev_pending_idx = pending_idx;
669
670 txp = &queue->pending_tx_info[pending_idx].req;
671 page = virt_to_page(idx_to_kaddr(queue, pending_idx));
672 __skb_fill_page_desc(skb, i, page, txp->offset, txp->size);
673 skb->len += txp->size;
674 skb->data_len += txp->size;
675 skb->truesize += txp->size;
676
677 /* Take an extra reference to offset network stack's put_page */
678 get_page(queue->mmap_pages[pending_idx]);
679 }
680}
681
682static int xenvif_get_extras(struct xenvif_queue *queue,
683 struct xen_netif_extra_info *extras,
684 unsigned int *extra_count,
685 int work_to_do)
686{
687 struct xen_netif_extra_info extra;
688 RING_IDX cons = queue->tx.req_cons;
689
690 do {
691 if (unlikely(work_to_do-- <= 0)) {
692 netdev_err(queue->vif->dev, "Missing extra info\n");
693 xenvif_fatal_tx_err(queue->vif);
694 return -EBADR;
695 }
696
697 RING_COPY_REQUEST(&queue->tx, cons, &extra);
698
699 queue->tx.req_cons = ++cons;
700 (*extra_count)++;
701
702 if (unlikely(!extra.type ||
703 extra.type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
704 netdev_err(queue->vif->dev,
705 "Invalid extra type: %d\n", extra.type);
706 xenvif_fatal_tx_err(queue->vif);
707 return -EINVAL;
708 }
709
710 memcpy(&extras[extra.type - 1], &extra, sizeof(extra));
711 } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE);
712
713 return work_to_do;
714}
715
716static int xenvif_set_skb_gso(struct xenvif *vif,
717 struct sk_buff *skb,
718 struct xen_netif_extra_info *gso)
719{
720 if (!gso->u.gso.size) {
721 netdev_err(vif->dev, "GSO size must not be zero.\n");
722 xenvif_fatal_tx_err(vif);
723 return -EINVAL;
724 }
725
726 switch (gso->u.gso.type) {
727 case XEN_NETIF_GSO_TYPE_TCPV4:
728 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
729 break;
730 case XEN_NETIF_GSO_TYPE_TCPV6:
731 skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
732 break;
733 default:
734 netdev_err(vif->dev, "Bad GSO type %d.\n", gso->u.gso.type);
735 xenvif_fatal_tx_err(vif);
736 return -EINVAL;
737 }
738
739 skb_shinfo(skb)->gso_size = gso->u.gso.size;
740 /* gso_segs will be calculated later */
741
742 return 0;
743}
744
745static int checksum_setup(struct xenvif_queue *queue, struct sk_buff *skb)
746{
747 bool recalculate_partial_csum = false;
748
749 /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
750 * peers can fail to set NETRXF_csum_blank when sending a GSO
751 * frame. In this case force the SKB to CHECKSUM_PARTIAL and
752 * recalculate the partial checksum.
753 */
754 if (skb->ip_summed != CHECKSUM_PARTIAL && skb_is_gso(skb)) {
755 queue->stats.rx_gso_checksum_fixup++;
756 skb->ip_summed = CHECKSUM_PARTIAL;
757 recalculate_partial_csum = true;
758 }
759
760 /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
761 if (skb->ip_summed != CHECKSUM_PARTIAL)
762 return 0;
763
764 return skb_checksum_setup(skb, recalculate_partial_csum);
765}
766
767static bool tx_credit_exceeded(struct xenvif_queue *queue, unsigned size)
768{
769 u64 now = get_jiffies_64();
770 u64 next_credit = queue->credit_window_start +
771 msecs_to_jiffies(queue->credit_usec / 1000);
772
773 /* Timer could already be pending in rare cases. */
774 if (timer_pending(&queue->credit_timeout)) {
775 queue->rate_limited = true;
776 return true;
777 }
778
779 /* Passed the point where we can replenish credit? */
780 if (time_after_eq64(now, next_credit)) {
781 queue->credit_window_start = now;
782 tx_add_credit(queue);
783 }
784
785 /* Still too big to send right now? Set a callback. */
786 if (size > queue->remaining_credit) {
787 mod_timer(&queue->credit_timeout,
788 next_credit);
789 queue->credit_window_start = next_credit;
790 queue->rate_limited = true;
791
792 return true;
793 }
794
795 return false;
796}
797
798/* No locking is required in xenvif_mcast_add/del() as they are
799 * only ever invoked from NAPI poll. An RCU list is used because
800 * xenvif_mcast_match() is called asynchronously, during start_xmit.
801 */
802
803static int xenvif_mcast_add(struct xenvif *vif, const u8 *addr)
804{
805 struct xenvif_mcast_addr *mcast;
806
807 if (vif->fe_mcast_count == XEN_NETBK_MCAST_MAX) {
808 if (net_ratelimit())
809 netdev_err(vif->dev,
810 "Too many multicast addresses\n");
811 return -ENOSPC;
812 }
813
814 mcast = kzalloc(sizeof(*mcast), GFP_ATOMIC);
815 if (!mcast)
816 return -ENOMEM;
817
818 ether_addr_copy(mcast->addr, addr);
819 list_add_tail_rcu(&mcast->entry, &vif->fe_mcast_addr);
820 vif->fe_mcast_count++;
821
822 return 0;
823}
824
825static void xenvif_mcast_del(struct xenvif *vif, const u8 *addr)
826{
827 struct xenvif_mcast_addr *mcast;
828
829 list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
830 if (ether_addr_equal(addr, mcast->addr)) {
831 --vif->fe_mcast_count;
832 list_del_rcu(&mcast->entry);
833 kfree_rcu(mcast, rcu);
834 break;
835 }
836 }
837}
838
839bool xenvif_mcast_match(struct xenvif *vif, const u8 *addr)
840{
841 struct xenvif_mcast_addr *mcast;
842
843 rcu_read_lock();
844 list_for_each_entry_rcu(mcast, &vif->fe_mcast_addr, entry) {
845 if (ether_addr_equal(addr, mcast->addr)) {
846 rcu_read_unlock();
847 return true;
848 }
849 }
850 rcu_read_unlock();
851
852 return false;
853}
854
855void xenvif_mcast_addr_list_free(struct xenvif *vif)
856{
857 /* No need for locking or RCU here. NAPI poll and TX queue
858 * are stopped.
859 */
860 while (!list_empty(&vif->fe_mcast_addr)) {
861 struct xenvif_mcast_addr *mcast;
862
863 mcast = list_first_entry(&vif->fe_mcast_addr,
864 struct xenvif_mcast_addr,
865 entry);
866 --vif->fe_mcast_count;
867 list_del(&mcast->entry);
868 kfree(mcast);
869 }
870}
871
872static void xenvif_tx_build_gops(struct xenvif_queue *queue,
873 int budget,
874 unsigned *copy_ops,
875 unsigned *map_ops)
876{
877 struct sk_buff *skb, *nskb;
878 int ret;
879 unsigned int frag_overflow;
880
881 while (skb_queue_len(&queue->tx_queue) < budget) {
882 struct xen_netif_tx_request txreq;
883 struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX];
884 struct xen_netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX-1];
885 unsigned int extra_count;
886 u16 pending_idx;
887 RING_IDX idx;
888 int work_to_do;
889 unsigned int data_len;
890 pending_ring_idx_t index;
891
892 if (queue->tx.sring->req_prod - queue->tx.req_cons >
893 XEN_NETIF_TX_RING_SIZE) {
894 netdev_err(queue->vif->dev,
895 "Impossible number of requests. "
896 "req_prod %d, req_cons %d, size %ld\n",
897 queue->tx.sring->req_prod, queue->tx.req_cons,
898 XEN_NETIF_TX_RING_SIZE);
899 xenvif_fatal_tx_err(queue->vif);
900 break;
901 }
902
903 work_to_do = XEN_RING_NR_UNCONSUMED_REQUESTS(&queue->tx);
904 if (!work_to_do)
905 break;
906
907 idx = queue->tx.req_cons;
908 rmb(); /* Ensure that we see the request before we copy it. */
909 RING_COPY_REQUEST(&queue->tx, idx, &txreq);
910
911 /* Credit-based scheduling. */
912 if (txreq.size > queue->remaining_credit &&
913 tx_credit_exceeded(queue, txreq.size))
914 break;
915
916 queue->remaining_credit -= txreq.size;
917
918 work_to_do--;
919 queue->tx.req_cons = ++idx;
920
921 memset(extras, 0, sizeof(extras));
922 extra_count = 0;
923 if (txreq.flags & XEN_NETTXF_extra_info) {
924 work_to_do = xenvif_get_extras(queue, extras,
925 &extra_count,
926 work_to_do);
927 idx = queue->tx.req_cons;
928 if (unlikely(work_to_do < 0))
929 break;
930 }
931
932 if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1].type) {
933 struct xen_netif_extra_info *extra;
934
935 extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_ADD - 1];
936 ret = xenvif_mcast_add(queue->vif, extra->u.mcast.addr);
937
938 make_tx_response(queue, &txreq, extra_count,
939 (ret == 0) ?
940 XEN_NETIF_RSP_OKAY :
941 XEN_NETIF_RSP_ERROR);
942 push_tx_responses(queue);
943 continue;
944 }
945
946 if (extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1].type) {
947 struct xen_netif_extra_info *extra;
948
949 extra = &extras[XEN_NETIF_EXTRA_TYPE_MCAST_DEL - 1];
950 xenvif_mcast_del(queue->vif, extra->u.mcast.addr);
951
952 make_tx_response(queue, &txreq, extra_count,
953 XEN_NETIF_RSP_OKAY);
954 push_tx_responses(queue);
955 continue;
956 }
957
958 data_len = (txreq.size > XEN_NETBACK_TX_COPY_LEN) ?
959 XEN_NETBACK_TX_COPY_LEN : txreq.size;
960
961 ret = xenvif_count_requests(queue, &txreq, extra_count,
962 txfrags, work_to_do);
963
964 if (unlikely(ret < 0))
965 break;
966
967 idx += ret;
968
969 if (unlikely(txreq.size < ETH_HLEN)) {
970 netdev_dbg(queue->vif->dev,
971 "Bad packet size: %d\n", txreq.size);
972 xenvif_tx_err(queue, &txreq, extra_count, idx);
973 break;
974 }
975
976 /* No crossing a page as the payload mustn't fragment. */
977 if (unlikely((txreq.offset + txreq.size) > XEN_PAGE_SIZE)) {
978 netdev_err(queue->vif->dev,
979 "txreq.offset: %u, size: %u, end: %lu\n",
980 txreq.offset, txreq.size,
981 (unsigned long)(txreq.offset&~XEN_PAGE_MASK) + txreq.size);
982 xenvif_fatal_tx_err(queue->vif);
983 break;
984 }
985
986 index = pending_index(queue->pending_cons);
987 pending_idx = queue->pending_ring[index];
988
989 if (ret >= XEN_NETBK_LEGACY_SLOTS_MAX - 1 && data_len < txreq.size)
990 data_len = txreq.size;
991
992 skb = xenvif_alloc_skb(data_len);
993 if (unlikely(skb == NULL)) {
994 netdev_dbg(queue->vif->dev,
995 "Can't allocate a skb in start_xmit.\n");
996 xenvif_tx_err(queue, &txreq, extra_count, idx);
997 break;
998 }
999
1000 skb_shinfo(skb)->nr_frags = ret;
1001 /* At this point shinfo->nr_frags is in fact the number of
1002 * slots, which can be as large as XEN_NETBK_LEGACY_SLOTS_MAX.
1003 */
1004 frag_overflow = 0;
1005 nskb = NULL;
1006 if (skb_shinfo(skb)->nr_frags > MAX_SKB_FRAGS) {
1007 frag_overflow = skb_shinfo(skb)->nr_frags - MAX_SKB_FRAGS;
1008 BUG_ON(frag_overflow > MAX_SKB_FRAGS);
1009 skb_shinfo(skb)->nr_frags = MAX_SKB_FRAGS;
1010 nskb = xenvif_alloc_skb(0);
1011 if (unlikely(nskb == NULL)) {
1012 skb_shinfo(skb)->nr_frags = 0;
1013 kfree_skb(skb);
1014 xenvif_tx_err(queue, &txreq, extra_count, idx);
1015 if (net_ratelimit())
1016 netdev_err(queue->vif->dev,
1017 "Can't allocate the frag_list skb.\n");
1018 break;
1019 }
1020 }
1021
1022 if (extras[XEN_NETIF_EXTRA_TYPE_GSO - 1].type) {
1023 struct xen_netif_extra_info *gso;
1024 gso = &extras[XEN_NETIF_EXTRA_TYPE_GSO - 1];
1025
1026 if (xenvif_set_skb_gso(queue->vif, skb, gso)) {
1027 /* Failure in xenvif_set_skb_gso is fatal. */
1028 skb_shinfo(skb)->nr_frags = 0;
1029 kfree_skb(skb);
1030 kfree_skb(nskb);
1031 break;
1032 }
1033 }
1034
1035 if (extras[XEN_NETIF_EXTRA_TYPE_HASH - 1].type) {
1036 struct xen_netif_extra_info *extra;
1037 enum pkt_hash_types type = PKT_HASH_TYPE_NONE;
1038
1039 extra = &extras[XEN_NETIF_EXTRA_TYPE_HASH - 1];
1040
1041 switch (extra->u.hash.type) {
1042 case _XEN_NETIF_CTRL_HASH_TYPE_IPV4:
1043 case _XEN_NETIF_CTRL_HASH_TYPE_IPV6:
1044 type = PKT_HASH_TYPE_L3;
1045 break;
1046
1047 case _XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP:
1048 case _XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP:
1049 type = PKT_HASH_TYPE_L4;
1050 break;
1051
1052 default:
1053 break;
1054 }
1055
1056 if (type != PKT_HASH_TYPE_NONE)
1057 skb_set_hash(skb,
1058 *(u32 *)extra->u.hash.value,
1059 type);
1060 }
1061
1062 xenvif_get_requests(queue, skb, &txreq, txfrags, copy_ops,
1063 map_ops, frag_overflow, nskb, extra_count,
1064 data_len);
1065
1066 __skb_queue_tail(&queue->tx_queue, skb);
1067
1068 queue->tx.req_cons = idx;
1069
1070 if ((*map_ops >= ARRAY_SIZE(queue->tx_map_ops)) ||
1071 (*copy_ops >= ARRAY_SIZE(queue->tx_copy_ops)))
1072 break;
1073 }
1074
1075 return;
1076}
1077
1078/* Consolidate skb with a frag_list into a brand new one with local pages on
1079 * frags. Returns 0 or -ENOMEM if can't allocate new pages.
1080 */
1081static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *skb)
1082{
1083 unsigned int offset = skb_headlen(skb);
1084 skb_frag_t frags[MAX_SKB_FRAGS];
1085 int i, f;
1086 struct ubuf_info *uarg;
1087 struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
1088
1089 queue->stats.tx_zerocopy_sent += 2;
1090 queue->stats.tx_frag_overflow++;
1091
1092 xenvif_fill_frags(queue, nskb);
1093 /* Subtract frags size, we will correct it later */
1094 skb->truesize -= skb->data_len;
1095 skb->len += nskb->len;
1096 skb->data_len += nskb->len;
1097
1098 /* create a brand new frags array and coalesce there */
1099 for (i = 0; offset < skb->len; i++) {
1100 struct page *page;
1101 unsigned int len;
1102
1103 BUG_ON(i >= MAX_SKB_FRAGS);
1104 page = alloc_page(GFP_ATOMIC);
1105 if (!page) {
1106 int j;
1107 skb->truesize += skb->data_len;
1108 for (j = 0; j < i; j++)
1109 put_page(skb_frag_page(&frags[j]));
1110 return -ENOMEM;
1111 }
1112
1113 if (offset + PAGE_SIZE < skb->len)
1114 len = PAGE_SIZE;
1115 else
1116 len = skb->len - offset;
1117 if (skb_copy_bits(skb, offset, page_address(page), len))
1118 BUG();
1119
1120 offset += len;
1121 __skb_frag_set_page(&frags[i], page);
1122 skb_frag_off_set(&frags[i], 0);
1123 skb_frag_size_set(&frags[i], len);
1124 }
1125
1126 /* Release all the original (foreign) frags. */
1127 for (f = 0; f < skb_shinfo(skb)->nr_frags; f++)
1128 skb_frag_unref(skb, f);
1129 uarg = skb_shinfo(skb)->destructor_arg;
1130 /* increase inflight counter to offset decrement in callback */
1131 atomic_inc(&queue->inflight_packets);
1132 uarg->callback(NULL, uarg, true);
1133 skb_shinfo(skb)->destructor_arg = NULL;
1134
1135 /* Fill the skb with the new (local) frags. */
1136 memcpy(skb_shinfo(skb)->frags, frags, i * sizeof(skb_frag_t));
1137 skb_shinfo(skb)->nr_frags = i;
1138 skb->truesize += i * PAGE_SIZE;
1139
1140 return 0;
1141}
1142
1143static int xenvif_tx_submit(struct xenvif_queue *queue)
1144{
1145 struct gnttab_map_grant_ref *gop_map = queue->tx_map_ops;
1146 struct gnttab_copy *gop_copy = queue->tx_copy_ops;
1147 struct sk_buff *skb;
1148 int work_done = 0;
1149
1150 while ((skb = __skb_dequeue(&queue->tx_queue)) != NULL) {
1151 struct xen_netif_tx_request *txp;
1152 u16 pending_idx;
1153
1154 pending_idx = copy_pending_idx(skb, 0);
1155 txp = &queue->pending_tx_info[pending_idx].req;
1156
1157 /* Check the remap error code. */
1158 if (unlikely(xenvif_tx_check_gop(queue, skb, &gop_map, &gop_copy))) {
1159 /* If there was an error, xenvif_tx_check_gop is
1160 * expected to release all the frags which were mapped,
1161 * so kfree_skb shouldn't do it again
1162 */
1163 skb_shinfo(skb)->nr_frags = 0;
1164 if (skb_has_frag_list(skb)) {
1165 struct sk_buff *nskb =
1166 skb_shinfo(skb)->frag_list;
1167 skb_shinfo(nskb)->nr_frags = 0;
1168 }
1169 kfree_skb(skb);
1170 continue;
1171 }
1172
1173 if (txp->flags & XEN_NETTXF_csum_blank)
1174 skb->ip_summed = CHECKSUM_PARTIAL;
1175 else if (txp->flags & XEN_NETTXF_data_validated)
1176 skb->ip_summed = CHECKSUM_UNNECESSARY;
1177
1178 xenvif_fill_frags(queue, skb);
1179
1180 if (unlikely(skb_has_frag_list(skb))) {
1181 struct sk_buff *nskb = skb_shinfo(skb)->frag_list;
1182 xenvif_skb_zerocopy_prepare(queue, nskb);
1183 if (xenvif_handle_frag_list(queue, skb)) {
1184 if (net_ratelimit())
1185 netdev_err(queue->vif->dev,
1186 "Not enough memory to consolidate frag_list!\n");
1187 xenvif_skb_zerocopy_prepare(queue, skb);
1188 kfree_skb(skb);
1189 continue;
1190 }
1191 /* Copied all the bits from the frag list -- free it. */
1192 skb_frag_list_init(skb);
1193 kfree_skb(nskb);
1194 }
1195
1196 skb->dev = queue->vif->dev;
1197 skb->protocol = eth_type_trans(skb, skb->dev);
1198 skb_reset_network_header(skb);
1199
1200 if (checksum_setup(queue, skb)) {
1201 netdev_dbg(queue->vif->dev,
1202 "Can't setup checksum in net_tx_action\n");
1203 /* We have to set this flag to trigger the callback */
1204 if (skb_shinfo(skb)->destructor_arg)
1205 xenvif_skb_zerocopy_prepare(queue, skb);
1206 kfree_skb(skb);
1207 continue;
1208 }
1209
1210 skb_probe_transport_header(skb);
1211
1212 /* If the packet is GSO then we will have just set up the
1213 * transport header offset in checksum_setup so it's now
1214 * straightforward to calculate gso_segs.
1215 */
1216 if (skb_is_gso(skb)) {
1217 int mss, hdrlen;
1218
1219 /* GSO implies having the L4 header. */
1220 WARN_ON_ONCE(!skb_transport_header_was_set(skb));
1221 if (unlikely(!skb_transport_header_was_set(skb))) {
1222 kfree_skb(skb);
1223 continue;
1224 }
1225
1226 mss = skb_shinfo(skb)->gso_size;
1227 hdrlen = skb_tcp_all_headers(skb);
1228
1229 skb_shinfo(skb)->gso_segs =
1230 DIV_ROUND_UP(skb->len - hdrlen, mss);
1231 }
1232
1233 queue->stats.rx_bytes += skb->len;
1234 queue->stats.rx_packets++;
1235
1236 work_done++;
1237
1238 /* Set this flag right before netif_receive_skb, otherwise
1239 * someone might think this packet already left netback, and
1240 * do a skb_copy_ubufs while we are still in control of the
1241 * skb. E.g. the __pskb_pull_tail earlier can do such thing.
1242 */
1243 if (skb_shinfo(skb)->destructor_arg) {
1244 xenvif_skb_zerocopy_prepare(queue, skb);
1245 queue->stats.tx_zerocopy_sent++;
1246 }
1247
1248 netif_receive_skb(skb);
1249 }
1250
1251 return work_done;
1252}
1253
1254void xenvif_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *ubuf_base,
1255 bool zerocopy_success)
1256{
1257 unsigned long flags;
1258 pending_ring_idx_t index;
1259 struct ubuf_info_msgzc *ubuf = uarg_to_msgzc(ubuf_base);
1260 struct xenvif_queue *queue = ubuf_to_queue(ubuf);
1261
1262 /* This is the only place where we grab this lock, to protect callbacks
1263 * from each other.
1264 */
1265 spin_lock_irqsave(&queue->callback_lock, flags);
1266 do {
1267 u16 pending_idx = ubuf->desc;
1268 ubuf = (struct ubuf_info_msgzc *) ubuf->ctx;
1269 BUG_ON(queue->dealloc_prod - queue->dealloc_cons >=
1270 MAX_PENDING_REQS);
1271 index = pending_index(queue->dealloc_prod);
1272 queue->dealloc_ring[index] = pending_idx;
1273 /* Sync with xenvif_tx_dealloc_action:
1274 * insert idx then incr producer.
1275 */
1276 smp_wmb();
1277 queue->dealloc_prod++;
1278 } while (ubuf);
1279 spin_unlock_irqrestore(&queue->callback_lock, flags);
1280
1281 if (likely(zerocopy_success))
1282 queue->stats.tx_zerocopy_success++;
1283 else
1284 queue->stats.tx_zerocopy_fail++;
1285 xenvif_skb_zerocopy_complete(queue);
1286}
1287
1288static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue)
1289{
1290 struct gnttab_unmap_grant_ref *gop;
1291 pending_ring_idx_t dc, dp;
1292 u16 pending_idx, pending_idx_release[MAX_PENDING_REQS];
1293 unsigned int i = 0;
1294
1295 dc = queue->dealloc_cons;
1296 gop = queue->tx_unmap_ops;
1297
1298 /* Free up any grants we have finished using */
1299 do {
1300 dp = queue->dealloc_prod;
1301
1302 /* Ensure we see all indices enqueued by all
1303 * xenvif_zerocopy_callback().
1304 */
1305 smp_rmb();
1306
1307 while (dc != dp) {
1308 BUG_ON(gop - queue->tx_unmap_ops >= MAX_PENDING_REQS);
1309 pending_idx =
1310 queue->dealloc_ring[pending_index(dc++)];
1311
1312 pending_idx_release[gop - queue->tx_unmap_ops] =
1313 pending_idx;
1314 queue->pages_to_unmap[gop - queue->tx_unmap_ops] =
1315 queue->mmap_pages[pending_idx];
1316 gnttab_set_unmap_op(gop,
1317 idx_to_kaddr(queue, pending_idx),
1318 GNTMAP_host_map,
1319 queue->grant_tx_handle[pending_idx]);
1320 xenvif_grant_handle_reset(queue, pending_idx);
1321 ++gop;
1322 }
1323
1324 } while (dp != queue->dealloc_prod);
1325
1326 queue->dealloc_cons = dc;
1327
1328 if (gop - queue->tx_unmap_ops > 0) {
1329 int ret;
1330 ret = gnttab_unmap_refs(queue->tx_unmap_ops,
1331 NULL,
1332 queue->pages_to_unmap,
1333 gop - queue->tx_unmap_ops);
1334 if (ret) {
1335 netdev_err(queue->vif->dev, "Unmap fail: nr_ops %tu ret %d\n",
1336 gop - queue->tx_unmap_ops, ret);
1337 for (i = 0; i < gop - queue->tx_unmap_ops; ++i) {
1338 if (gop[i].status != GNTST_okay)
1339 netdev_err(queue->vif->dev,
1340 " host_addr: 0x%llx handle: 0x%x status: %d\n",
1341 gop[i].host_addr,
1342 gop[i].handle,
1343 gop[i].status);
1344 }
1345 BUG();
1346 }
1347 }
1348
1349 for (i = 0; i < gop - queue->tx_unmap_ops; ++i)
1350 xenvif_idx_release(queue, pending_idx_release[i],
1351 XEN_NETIF_RSP_OKAY);
1352}
1353
1354
1355/* Called after netfront has transmitted */
1356int xenvif_tx_action(struct xenvif_queue *queue, int budget)
1357{
1358 unsigned nr_mops = 0, nr_cops = 0;
1359 int work_done, ret;
1360
1361 if (unlikely(!tx_work_todo(queue)))
1362 return 0;
1363
1364 xenvif_tx_build_gops(queue, budget, &nr_cops, &nr_mops);
1365
1366 if (nr_cops == 0)
1367 return 0;
1368
1369 gnttab_batch_copy(queue->tx_copy_ops, nr_cops);
1370 if (nr_mops != 0) {
1371 ret = gnttab_map_refs(queue->tx_map_ops,
1372 NULL,
1373 queue->pages_to_map,
1374 nr_mops);
1375 if (ret) {
1376 unsigned int i;
1377
1378 netdev_err(queue->vif->dev, "Map fail: nr %u ret %d\n",
1379 nr_mops, ret);
1380 for (i = 0; i < nr_mops; ++i)
1381 WARN_ON_ONCE(queue->tx_map_ops[i].status ==
1382 GNTST_okay);
1383 }
1384 }
1385
1386 work_done = xenvif_tx_submit(queue);
1387
1388 return work_done;
1389}
1390
1391static void xenvif_idx_release(struct xenvif_queue *queue, u16 pending_idx,
1392 u8 status)
1393{
1394 struct pending_tx_info *pending_tx_info;
1395 pending_ring_idx_t index;
1396 unsigned long flags;
1397
1398 pending_tx_info = &queue->pending_tx_info[pending_idx];
1399
1400 spin_lock_irqsave(&queue->response_lock, flags);
1401
1402 make_tx_response(queue, &pending_tx_info->req,
1403 pending_tx_info->extra_count, status);
1404
1405 /* Release the pending index before pusing the Tx response so
1406 * its available before a new Tx request is pushed by the
1407 * frontend.
1408 */
1409 index = pending_index(queue->pending_prod++);
1410 queue->pending_ring[index] = pending_idx;
1411
1412 push_tx_responses(queue);
1413
1414 spin_unlock_irqrestore(&queue->response_lock, flags);
1415}
1416
1417
1418static void make_tx_response(struct xenvif_queue *queue,
1419 struct xen_netif_tx_request *txp,
1420 unsigned int extra_count,
1421 s8 st)
1422{
1423 RING_IDX i = queue->tx.rsp_prod_pvt;
1424 struct xen_netif_tx_response *resp;
1425
1426 resp = RING_GET_RESPONSE(&queue->tx, i);
1427 resp->id = txp->id;
1428 resp->status = st;
1429
1430 while (extra_count-- != 0)
1431 RING_GET_RESPONSE(&queue->tx, ++i)->status = XEN_NETIF_RSP_NULL;
1432
1433 queue->tx.rsp_prod_pvt = ++i;
1434}
1435
1436static void push_tx_responses(struct xenvif_queue *queue)
1437{
1438 int notify;
1439
1440 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&queue->tx, notify);
1441 if (notify)
1442 notify_remote_via_irq(queue->tx_irq);
1443}
1444
1445static void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx)
1446{
1447 int ret;
1448 struct gnttab_unmap_grant_ref tx_unmap_op;
1449
1450 gnttab_set_unmap_op(&tx_unmap_op,
1451 idx_to_kaddr(queue, pending_idx),
1452 GNTMAP_host_map,
1453 queue->grant_tx_handle[pending_idx]);
1454 xenvif_grant_handle_reset(queue, pending_idx);
1455
1456 ret = gnttab_unmap_refs(&tx_unmap_op, NULL,
1457 &queue->mmap_pages[pending_idx], 1);
1458 if (ret) {
1459 netdev_err(queue->vif->dev,
1460 "Unmap fail: ret: %d pending_idx: %d host_addr: %llx handle: 0x%x status: %d\n",
1461 ret,
1462 pending_idx,
1463 tx_unmap_op.host_addr,
1464 tx_unmap_op.handle,
1465 tx_unmap_op.status);
1466 BUG();
1467 }
1468}
1469
1470static inline int tx_work_todo(struct xenvif_queue *queue)
1471{
1472 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&queue->tx)))
1473 return 1;
1474
1475 return 0;
1476}
1477
1478static inline bool tx_dealloc_work_todo(struct xenvif_queue *queue)
1479{
1480 return queue->dealloc_cons != queue->dealloc_prod;
1481}
1482
1483void xenvif_unmap_frontend_data_rings(struct xenvif_queue *queue)
1484{
1485 if (queue->tx.sring)
1486 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
1487 queue->tx.sring);
1488 if (queue->rx.sring)
1489 xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(queue->vif),
1490 queue->rx.sring);
1491}
1492
1493int xenvif_map_frontend_data_rings(struct xenvif_queue *queue,
1494 grant_ref_t tx_ring_ref,
1495 grant_ref_t rx_ring_ref)
1496{
1497 void *addr;
1498 struct xen_netif_tx_sring *txs;
1499 struct xen_netif_rx_sring *rxs;
1500 RING_IDX rsp_prod, req_prod;
1501 int err;
1502
1503 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
1504 &tx_ring_ref, 1, &addr);
1505 if (err)
1506 goto err;
1507
1508 txs = (struct xen_netif_tx_sring *)addr;
1509 rsp_prod = READ_ONCE(txs->rsp_prod);
1510 req_prod = READ_ONCE(txs->req_prod);
1511
1512 BACK_RING_ATTACH(&queue->tx, txs, rsp_prod, XEN_PAGE_SIZE);
1513
1514 err = -EIO;
1515 if (req_prod - rsp_prod > RING_SIZE(&queue->tx))
1516 goto err;
1517
1518 err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(queue->vif),
1519 &rx_ring_ref, 1, &addr);
1520 if (err)
1521 goto err;
1522
1523 rxs = (struct xen_netif_rx_sring *)addr;
1524 rsp_prod = READ_ONCE(rxs->rsp_prod);
1525 req_prod = READ_ONCE(rxs->req_prod);
1526
1527 BACK_RING_ATTACH(&queue->rx, rxs, rsp_prod, XEN_PAGE_SIZE);
1528
1529 err = -EIO;
1530 if (req_prod - rsp_prod > RING_SIZE(&queue->rx))
1531 goto err;
1532
1533 return 0;
1534
1535err:
1536 xenvif_unmap_frontend_data_rings(queue);
1537 return err;
1538}
1539
1540static bool xenvif_dealloc_kthread_should_stop(struct xenvif_queue *queue)
1541{
1542 /* Dealloc thread must remain running until all inflight
1543 * packets complete.
1544 */
1545 return kthread_should_stop() &&
1546 !atomic_read(&queue->inflight_packets);
1547}
1548
1549int xenvif_dealloc_kthread(void *data)
1550{
1551 struct xenvif_queue *queue = data;
1552
1553 for (;;) {
1554 wait_event_interruptible(queue->dealloc_wq,
1555 tx_dealloc_work_todo(queue) ||
1556 xenvif_dealloc_kthread_should_stop(queue));
1557 if (xenvif_dealloc_kthread_should_stop(queue))
1558 break;
1559
1560 xenvif_tx_dealloc_action(queue);
1561 cond_resched();
1562 }
1563
1564 /* Unmap anything remaining*/
1565 if (tx_dealloc_work_todo(queue))
1566 xenvif_tx_dealloc_action(queue);
1567
1568 return 0;
1569}
1570
1571static void make_ctrl_response(struct xenvif *vif,
1572 const struct xen_netif_ctrl_request *req,
1573 u32 status, u32 data)
1574{
1575 RING_IDX idx = vif->ctrl.rsp_prod_pvt;
1576 struct xen_netif_ctrl_response rsp = {
1577 .id = req->id,
1578 .type = req->type,
1579 .status = status,
1580 .data = data,
1581 };
1582
1583 *RING_GET_RESPONSE(&vif->ctrl, idx) = rsp;
1584 vif->ctrl.rsp_prod_pvt = ++idx;
1585}
1586
1587static void push_ctrl_response(struct xenvif *vif)
1588{
1589 int notify;
1590
1591 RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->ctrl, notify);
1592 if (notify)
1593 notify_remote_via_irq(vif->ctrl_irq);
1594}
1595
1596static void process_ctrl_request(struct xenvif *vif,
1597 const struct xen_netif_ctrl_request *req)
1598{
1599 u32 status = XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED;
1600 u32 data = 0;
1601
1602 switch (req->type) {
1603 case XEN_NETIF_CTRL_TYPE_SET_HASH_ALGORITHM:
1604 status = xenvif_set_hash_alg(vif, req->data[0]);
1605 break;
1606
1607 case XEN_NETIF_CTRL_TYPE_GET_HASH_FLAGS:
1608 status = xenvif_get_hash_flags(vif, &data);
1609 break;
1610
1611 case XEN_NETIF_CTRL_TYPE_SET_HASH_FLAGS:
1612 status = xenvif_set_hash_flags(vif, req->data[0]);
1613 break;
1614
1615 case XEN_NETIF_CTRL_TYPE_SET_HASH_KEY:
1616 status = xenvif_set_hash_key(vif, req->data[0],
1617 req->data[1]);
1618 break;
1619
1620 case XEN_NETIF_CTRL_TYPE_GET_HASH_MAPPING_SIZE:
1621 status = XEN_NETIF_CTRL_STATUS_SUCCESS;
1622 data = XEN_NETBK_MAX_HASH_MAPPING_SIZE;
1623 break;
1624
1625 case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING_SIZE:
1626 status = xenvif_set_hash_mapping_size(vif,
1627 req->data[0]);
1628 break;
1629
1630 case XEN_NETIF_CTRL_TYPE_SET_HASH_MAPPING:
1631 status = xenvif_set_hash_mapping(vif, req->data[0],
1632 req->data[1],
1633 req->data[2]);
1634 break;
1635
1636 default:
1637 break;
1638 }
1639
1640 make_ctrl_response(vif, req, status, data);
1641 push_ctrl_response(vif);
1642}
1643
1644static void xenvif_ctrl_action(struct xenvif *vif)
1645{
1646 for (;;) {
1647 RING_IDX req_prod, req_cons;
1648
1649 req_prod = vif->ctrl.sring->req_prod;
1650 req_cons = vif->ctrl.req_cons;
1651
1652 /* Make sure we can see requests before we process them. */
1653 rmb();
1654
1655 if (req_cons == req_prod)
1656 break;
1657
1658 while (req_cons != req_prod) {
1659 struct xen_netif_ctrl_request req;
1660
1661 RING_COPY_REQUEST(&vif->ctrl, req_cons, &req);
1662 req_cons++;
1663
1664 process_ctrl_request(vif, &req);
1665 }
1666
1667 vif->ctrl.req_cons = req_cons;
1668 vif->ctrl.sring->req_event = req_cons + 1;
1669 }
1670}
1671
1672static bool xenvif_ctrl_work_todo(struct xenvif *vif)
1673{
1674 if (likely(RING_HAS_UNCONSUMED_REQUESTS(&vif->ctrl)))
1675 return true;
1676
1677 return false;
1678}
1679
1680irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data)
1681{
1682 struct xenvif *vif = data;
1683 unsigned int eoi_flag = XEN_EOI_FLAG_SPURIOUS;
1684
1685 while (xenvif_ctrl_work_todo(vif)) {
1686 xenvif_ctrl_action(vif);
1687 eoi_flag = 0;
1688 }
1689
1690 xen_irq_lateeoi(irq, eoi_flag);
1691
1692 return IRQ_HANDLED;
1693}
1694
1695static int __init netback_init(void)
1696{
1697 int rc = 0;
1698
1699 if (!xen_domain())
1700 return -ENODEV;
1701
1702 /* Allow as many queues as there are CPUs but max. 8 if user has not
1703 * specified a value.
1704 */
1705 if (xenvif_max_queues == 0)
1706 xenvif_max_queues = min_t(unsigned int, MAX_QUEUES_DEFAULT,
1707 num_online_cpus());
1708
1709 if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
1710 pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",
1711 fatal_skb_slots, XEN_NETBK_LEGACY_SLOTS_MAX);
1712 fatal_skb_slots = XEN_NETBK_LEGACY_SLOTS_MAX;
1713 }
1714
1715 rc = xenvif_xenbus_init();
1716 if (rc)
1717 goto failed_init;
1718
1719#ifdef CONFIG_DEBUG_FS
1720 xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL);
1721#endif /* CONFIG_DEBUG_FS */
1722
1723 return 0;
1724
1725failed_init:
1726 return rc;
1727}
1728
1729module_init(netback_init);
1730
1731static void __exit netback_fini(void)
1732{
1733#ifdef CONFIG_DEBUG_FS
1734 debugfs_remove_recursive(xen_netback_dbg_root);
1735#endif /* CONFIG_DEBUG_FS */
1736 xenvif_xenbus_fini();
1737}
1738module_exit(netback_fini);
1739
1740MODULE_LICENSE("Dual BSD/GPL");
1741MODULE_ALIAS("xen-backend:vif");