xref: /dpdk/lib/vhost/virtio_net.c (revision 30a1de105a5f40d77b344a891c4a68f79e815c43)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2016 Intel Corporation
3  */
4 
5 #include <stdint.h>
6 #include <stdbool.h>
7 #include <linux/virtio_net.h>
8 
9 #include <rte_mbuf.h>
10 #include <rte_memcpy.h>
11 #include <rte_net.h>
12 #include <rte_ether.h>
13 #include <rte_ip.h>
14 #include <rte_dmadev.h>
15 #include <rte_vhost.h>
16 #include <rte_tcp.h>
17 #include <rte_udp.h>
18 #include <rte_sctp.h>
19 #include <rte_arp.h>
20 #include <rte_spinlock.h>
21 #include <rte_malloc.h>
22 #include <rte_vhost_async.h>
23 
24 #include "iotlb.h"
25 #include "vhost.h"
26 
27 #define MAX_BATCH_LEN 256
28 
29 /* DMA device copy operation tracking array. */
30 struct async_dma_info dma_copy_track[RTE_DMADEV_DEFAULT_MAX];
31 
32 static  __rte_always_inline bool
33 rxvq_is_mergeable(struct virtio_net *dev)
34 {
35 	return dev->features & (1ULL << VIRTIO_NET_F_MRG_RXBUF);
36 }
37 
38 static  __rte_always_inline bool
39 virtio_net_is_inorder(struct virtio_net *dev)
40 {
41 	return dev->features & (1ULL << VIRTIO_F_IN_ORDER);
42 }
43 
44 static bool
45 is_valid_virt_queue_idx(uint32_t idx, int is_tx, uint32_t nr_vring)
46 {
47 	return (is_tx ^ (idx & 1)) == 0 && idx < nr_vring;
48 }
49 
50 static __rte_always_inline int64_t
51 vhost_async_dma_transfer_one(struct virtio_net *dev, struct vhost_virtqueue *vq,
52 		int16_t dma_id, uint16_t vchan_id, uint16_t flag_idx,
53 		struct vhost_iov_iter *pkt)
54 {
55 	struct async_dma_vchan_info *dma_info = &dma_copy_track[dma_id].vchans[vchan_id];
56 	uint16_t ring_mask = dma_info->ring_mask;
57 	static bool vhost_async_dma_copy_log;
58 
59 
60 	struct vhost_iovec *iov = pkt->iov;
61 	int copy_idx = 0;
62 	uint32_t nr_segs = pkt->nr_segs;
63 	uint16_t i;
64 
65 	if (rte_dma_burst_capacity(dma_id, vchan_id) < nr_segs)
66 		return -1;
67 
68 	for (i = 0; i < nr_segs; i++) {
69 		copy_idx = rte_dma_copy(dma_id, vchan_id, (rte_iova_t)iov[i].src_addr,
70 				(rte_iova_t)iov[i].dst_addr, iov[i].len, RTE_DMA_OP_FLAG_LLC);
71 		/**
72 		 * Since all memory is pinned and DMA vChannel
73 		 * ring has enough space, failure should be a
74 		 * rare case. If failure happens, it means DMA
75 		 * device encounters serious errors; in this
76 		 * case, please stop async data-path and check
77 		 * what has happened to DMA device.
78 		 */
79 		if (unlikely(copy_idx < 0)) {
80 			if (!vhost_async_dma_copy_log) {
81 				VHOST_LOG_DATA(ERR, "(%s) DMA copy failed for channel %d:%u\n",
82 						dev->ifname, dma_id, vchan_id);
83 				vhost_async_dma_copy_log = true;
84 			}
85 			return -1;
86 		}
87 	}
88 
89 	/**
90 	 * Only store packet completion flag address in the last copy's
91 	 * slot, and other slots are set to NULL.
92 	 */
93 	dma_info->pkts_cmpl_flag_addr[copy_idx & ring_mask] = &vq->async->pkts_cmpl_flag[flag_idx];
94 
95 	return nr_segs;
96 }
97 
98 static __rte_always_inline uint16_t
99 vhost_async_dma_transfer(struct virtio_net *dev, struct vhost_virtqueue *vq,
100 		int16_t dma_id, uint16_t vchan_id, uint16_t head_idx,
101 		struct vhost_iov_iter *pkts, uint16_t nr_pkts)
102 {
103 	struct async_dma_vchan_info *dma_info = &dma_copy_track[dma_id].vchans[vchan_id];
104 	int64_t ret, nr_copies = 0;
105 	uint16_t pkt_idx;
106 
107 	rte_spinlock_lock(&dma_info->dma_lock);
108 
109 	for (pkt_idx = 0; pkt_idx < nr_pkts; pkt_idx++) {
110 		ret = vhost_async_dma_transfer_one(dev, vq, dma_id, vchan_id, head_idx,
111 				&pkts[pkt_idx]);
112 		if (unlikely(ret < 0))
113 			break;
114 
115 		nr_copies += ret;
116 		head_idx++;
117 		if (head_idx >= vq->size)
118 			head_idx -= vq->size;
119 	}
120 
121 	if (likely(nr_copies > 0))
122 		rte_dma_submit(dma_id, vchan_id);
123 
124 	rte_spinlock_unlock(&dma_info->dma_lock);
125 
126 	return pkt_idx;
127 }
128 
129 static __rte_always_inline uint16_t
130 vhost_async_dma_check_completed(struct virtio_net *dev, int16_t dma_id, uint16_t vchan_id,
131 		uint16_t max_pkts)
132 {
133 	struct async_dma_vchan_info *dma_info = &dma_copy_track[dma_id].vchans[vchan_id];
134 	uint16_t ring_mask = dma_info->ring_mask;
135 	uint16_t last_idx = 0;
136 	uint16_t nr_copies;
137 	uint16_t copy_idx;
138 	uint16_t i;
139 	bool has_error = false;
140 	static bool vhost_async_dma_complete_log;
141 
142 	rte_spinlock_lock(&dma_info->dma_lock);
143 
144 	/**
145 	 * Print error log for debugging, if DMA reports error during
146 	 * DMA transfer. We do not handle error in vhost level.
147 	 */
148 	nr_copies = rte_dma_completed(dma_id, vchan_id, max_pkts, &last_idx, &has_error);
149 	if (unlikely(!vhost_async_dma_complete_log && has_error)) {
150 		VHOST_LOG_DATA(ERR, "(%s) DMA completion failure on channel %d:%u\n", dev->ifname,
151 				dma_id, vchan_id);
152 		vhost_async_dma_complete_log = true;
153 	} else if (nr_copies == 0) {
154 		goto out;
155 	}
156 
157 	copy_idx = last_idx - nr_copies + 1;
158 	for (i = 0; i < nr_copies; i++) {
159 		bool *flag;
160 
161 		flag = dma_info->pkts_cmpl_flag_addr[copy_idx & ring_mask];
162 		if (flag) {
163 			/**
164 			 * Mark the packet flag as received. The flag
165 			 * could belong to another virtqueue but write
166 			 * is atomic.
167 			 */
168 			*flag = true;
169 			dma_info->pkts_cmpl_flag_addr[copy_idx & ring_mask] = NULL;
170 		}
171 		copy_idx++;
172 	}
173 
174 out:
175 	rte_spinlock_unlock(&dma_info->dma_lock);
176 	return nr_copies;
177 }
178 
179 static inline void
180 do_data_copy_enqueue(struct virtio_net *dev, struct vhost_virtqueue *vq)
181 {
182 	struct batch_copy_elem *elem = vq->batch_copy_elems;
183 	uint16_t count = vq->batch_copy_nb_elems;
184 	int i;
185 
186 	for (i = 0; i < count; i++) {
187 		rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
188 		vhost_log_cache_write_iova(dev, vq, elem[i].log_addr,
189 					   elem[i].len);
190 		PRINT_PACKET(dev, (uintptr_t)elem[i].dst, elem[i].len, 0);
191 	}
192 
193 	vq->batch_copy_nb_elems = 0;
194 }
195 
196 static inline void
197 do_data_copy_dequeue(struct vhost_virtqueue *vq)
198 {
199 	struct batch_copy_elem *elem = vq->batch_copy_elems;
200 	uint16_t count = vq->batch_copy_nb_elems;
201 	int i;
202 
203 	for (i = 0; i < count; i++)
204 		rte_memcpy(elem[i].dst, elem[i].src, elem[i].len);
205 
206 	vq->batch_copy_nb_elems = 0;
207 }
208 
209 static __rte_always_inline void
210 do_flush_shadow_used_ring_split(struct virtio_net *dev,
211 			struct vhost_virtqueue *vq,
212 			uint16_t to, uint16_t from, uint16_t size)
213 {
214 	rte_memcpy(&vq->used->ring[to],
215 			&vq->shadow_used_split[from],
216 			size * sizeof(struct vring_used_elem));
217 	vhost_log_cache_used_vring(dev, vq,
218 			offsetof(struct vring_used, ring[to]),
219 			size * sizeof(struct vring_used_elem));
220 }
221 
222 static __rte_always_inline void
223 flush_shadow_used_ring_split(struct virtio_net *dev, struct vhost_virtqueue *vq)
224 {
225 	uint16_t used_idx = vq->last_used_idx & (vq->size - 1);
226 
227 	if (used_idx + vq->shadow_used_idx <= vq->size) {
228 		do_flush_shadow_used_ring_split(dev, vq, used_idx, 0,
229 					  vq->shadow_used_idx);
230 	} else {
231 		uint16_t size;
232 
233 		/* update used ring interval [used_idx, vq->size] */
234 		size = vq->size - used_idx;
235 		do_flush_shadow_used_ring_split(dev, vq, used_idx, 0, size);
236 
237 		/* update the left half used ring interval [0, left_size] */
238 		do_flush_shadow_used_ring_split(dev, vq, 0, size,
239 					  vq->shadow_used_idx - size);
240 	}
241 	vq->last_used_idx += vq->shadow_used_idx;
242 
243 	vhost_log_cache_sync(dev, vq);
244 
245 	__atomic_add_fetch(&vq->used->idx, vq->shadow_used_idx,
246 			   __ATOMIC_RELEASE);
247 	vq->shadow_used_idx = 0;
248 	vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
249 		sizeof(vq->used->idx));
250 }
251 
252 static __rte_always_inline void
253 update_shadow_used_ring_split(struct vhost_virtqueue *vq,
254 			 uint16_t desc_idx, uint32_t len)
255 {
256 	uint16_t i = vq->shadow_used_idx++;
257 
258 	vq->shadow_used_split[i].id  = desc_idx;
259 	vq->shadow_used_split[i].len = len;
260 }
261 
262 static __rte_always_inline void
263 vhost_flush_enqueue_shadow_packed(struct virtio_net *dev,
264 				  struct vhost_virtqueue *vq)
265 {
266 	int i;
267 	uint16_t used_idx = vq->last_used_idx;
268 	uint16_t head_idx = vq->last_used_idx;
269 	uint16_t head_flags = 0;
270 
271 	/* Split loop in two to save memory barriers */
272 	for (i = 0; i < vq->shadow_used_idx; i++) {
273 		vq->desc_packed[used_idx].id = vq->shadow_used_packed[i].id;
274 		vq->desc_packed[used_idx].len = vq->shadow_used_packed[i].len;
275 
276 		used_idx += vq->shadow_used_packed[i].count;
277 		if (used_idx >= vq->size)
278 			used_idx -= vq->size;
279 	}
280 
281 	/* The ordering for storing desc flags needs to be enforced. */
282 	rte_atomic_thread_fence(__ATOMIC_RELEASE);
283 
284 	for (i = 0; i < vq->shadow_used_idx; i++) {
285 		uint16_t flags;
286 
287 		if (vq->shadow_used_packed[i].len)
288 			flags = VRING_DESC_F_WRITE;
289 		else
290 			flags = 0;
291 
292 		if (vq->used_wrap_counter) {
293 			flags |= VRING_DESC_F_USED;
294 			flags |= VRING_DESC_F_AVAIL;
295 		} else {
296 			flags &= ~VRING_DESC_F_USED;
297 			flags &= ~VRING_DESC_F_AVAIL;
298 		}
299 
300 		if (i > 0) {
301 			vq->desc_packed[vq->last_used_idx].flags = flags;
302 
303 			vhost_log_cache_used_vring(dev, vq,
304 					vq->last_used_idx *
305 					sizeof(struct vring_packed_desc),
306 					sizeof(struct vring_packed_desc));
307 		} else {
308 			head_idx = vq->last_used_idx;
309 			head_flags = flags;
310 		}
311 
312 		vq_inc_last_used_packed(vq, vq->shadow_used_packed[i].count);
313 	}
314 
315 	vq->desc_packed[head_idx].flags = head_flags;
316 
317 	vhost_log_cache_used_vring(dev, vq,
318 				head_idx *
319 				sizeof(struct vring_packed_desc),
320 				sizeof(struct vring_packed_desc));
321 
322 	vq->shadow_used_idx = 0;
323 	vhost_log_cache_sync(dev, vq);
324 }
325 
326 static __rte_always_inline void
327 vhost_flush_dequeue_shadow_packed(struct virtio_net *dev,
328 				  struct vhost_virtqueue *vq)
329 {
330 	struct vring_used_elem_packed *used_elem = &vq->shadow_used_packed[0];
331 
332 	vq->desc_packed[vq->shadow_last_used_idx].id = used_elem->id;
333 	/* desc flags is the synchronization point for virtio packed vring */
334 	__atomic_store_n(&vq->desc_packed[vq->shadow_last_used_idx].flags,
335 			 used_elem->flags, __ATOMIC_RELEASE);
336 
337 	vhost_log_cache_used_vring(dev, vq, vq->shadow_last_used_idx *
338 				   sizeof(struct vring_packed_desc),
339 				   sizeof(struct vring_packed_desc));
340 	vq->shadow_used_idx = 0;
341 	vhost_log_cache_sync(dev, vq);
342 }
343 
344 static __rte_always_inline void
345 vhost_flush_enqueue_batch_packed(struct virtio_net *dev,
346 				 struct vhost_virtqueue *vq,
347 				 uint64_t *lens,
348 				 uint16_t *ids)
349 {
350 	uint16_t i;
351 	uint16_t flags;
352 	uint16_t last_used_idx;
353 	struct vring_packed_desc *desc_base;
354 
355 	last_used_idx = vq->last_used_idx;
356 	desc_base = &vq->desc_packed[last_used_idx];
357 
358 	flags = PACKED_DESC_ENQUEUE_USED_FLAG(vq->used_wrap_counter);
359 
360 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
361 		desc_base[i].id = ids[i];
362 		desc_base[i].len = lens[i];
363 	}
364 
365 	rte_atomic_thread_fence(__ATOMIC_RELEASE);
366 
367 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
368 		desc_base[i].flags = flags;
369 	}
370 
371 	vhost_log_cache_used_vring(dev, vq, last_used_idx *
372 				   sizeof(struct vring_packed_desc),
373 				   sizeof(struct vring_packed_desc) *
374 				   PACKED_BATCH_SIZE);
375 	vhost_log_cache_sync(dev, vq);
376 
377 	vq_inc_last_used_packed(vq, PACKED_BATCH_SIZE);
378 }
379 
380 static __rte_always_inline void
381 vhost_shadow_dequeue_batch_packed_inorder(struct vhost_virtqueue *vq,
382 					  uint16_t id)
383 {
384 	vq->shadow_used_packed[0].id = id;
385 
386 	if (!vq->shadow_used_idx) {
387 		vq->shadow_last_used_idx = vq->last_used_idx;
388 		vq->shadow_used_packed[0].flags =
389 			PACKED_DESC_DEQUEUE_USED_FLAG(vq->used_wrap_counter);
390 		vq->shadow_used_packed[0].len = 0;
391 		vq->shadow_used_packed[0].count = 1;
392 		vq->shadow_used_idx++;
393 	}
394 
395 	vq_inc_last_used_packed(vq, PACKED_BATCH_SIZE);
396 }
397 
398 static __rte_always_inline void
399 vhost_shadow_dequeue_batch_packed(struct virtio_net *dev,
400 				  struct vhost_virtqueue *vq,
401 				  uint16_t *ids)
402 {
403 	uint16_t flags;
404 	uint16_t i;
405 	uint16_t begin;
406 
407 	flags = PACKED_DESC_DEQUEUE_USED_FLAG(vq->used_wrap_counter);
408 
409 	if (!vq->shadow_used_idx) {
410 		vq->shadow_last_used_idx = vq->last_used_idx;
411 		vq->shadow_used_packed[0].id  = ids[0];
412 		vq->shadow_used_packed[0].len = 0;
413 		vq->shadow_used_packed[0].count = 1;
414 		vq->shadow_used_packed[0].flags = flags;
415 		vq->shadow_used_idx++;
416 		begin = 1;
417 	} else
418 		begin = 0;
419 
420 	vhost_for_each_try_unroll(i, begin, PACKED_BATCH_SIZE) {
421 		vq->desc_packed[vq->last_used_idx + i].id = ids[i];
422 		vq->desc_packed[vq->last_used_idx + i].len = 0;
423 	}
424 
425 	rte_atomic_thread_fence(__ATOMIC_RELEASE);
426 	vhost_for_each_try_unroll(i, begin, PACKED_BATCH_SIZE)
427 		vq->desc_packed[vq->last_used_idx + i].flags = flags;
428 
429 	vhost_log_cache_used_vring(dev, vq, vq->last_used_idx *
430 				   sizeof(struct vring_packed_desc),
431 				   sizeof(struct vring_packed_desc) *
432 				   PACKED_BATCH_SIZE);
433 	vhost_log_cache_sync(dev, vq);
434 
435 	vq_inc_last_used_packed(vq, PACKED_BATCH_SIZE);
436 }
437 
438 static __rte_always_inline void
439 vhost_shadow_dequeue_single_packed(struct vhost_virtqueue *vq,
440 				   uint16_t buf_id,
441 				   uint16_t count)
442 {
443 	uint16_t flags;
444 
445 	flags = vq->desc_packed[vq->last_used_idx].flags;
446 	if (vq->used_wrap_counter) {
447 		flags |= VRING_DESC_F_USED;
448 		flags |= VRING_DESC_F_AVAIL;
449 	} else {
450 		flags &= ~VRING_DESC_F_USED;
451 		flags &= ~VRING_DESC_F_AVAIL;
452 	}
453 
454 	if (!vq->shadow_used_idx) {
455 		vq->shadow_last_used_idx = vq->last_used_idx;
456 
457 		vq->shadow_used_packed[0].id  = buf_id;
458 		vq->shadow_used_packed[0].len = 0;
459 		vq->shadow_used_packed[0].flags = flags;
460 		vq->shadow_used_idx++;
461 	} else {
462 		vq->desc_packed[vq->last_used_idx].id = buf_id;
463 		vq->desc_packed[vq->last_used_idx].len = 0;
464 		vq->desc_packed[vq->last_used_idx].flags = flags;
465 	}
466 
467 	vq_inc_last_used_packed(vq, count);
468 }
469 
470 static __rte_always_inline void
471 vhost_shadow_dequeue_single_packed_inorder(struct vhost_virtqueue *vq,
472 					   uint16_t buf_id,
473 					   uint16_t count)
474 {
475 	uint16_t flags;
476 
477 	vq->shadow_used_packed[0].id = buf_id;
478 
479 	flags = vq->desc_packed[vq->last_used_idx].flags;
480 	if (vq->used_wrap_counter) {
481 		flags |= VRING_DESC_F_USED;
482 		flags |= VRING_DESC_F_AVAIL;
483 	} else {
484 		flags &= ~VRING_DESC_F_USED;
485 		flags &= ~VRING_DESC_F_AVAIL;
486 	}
487 
488 	if (!vq->shadow_used_idx) {
489 		vq->shadow_last_used_idx = vq->last_used_idx;
490 		vq->shadow_used_packed[0].len = 0;
491 		vq->shadow_used_packed[0].flags = flags;
492 		vq->shadow_used_idx++;
493 	}
494 
495 	vq_inc_last_used_packed(vq, count);
496 }
497 
498 static __rte_always_inline void
499 vhost_shadow_enqueue_packed(struct vhost_virtqueue *vq,
500 				   uint32_t *len,
501 				   uint16_t *id,
502 				   uint16_t *count,
503 				   uint16_t num_buffers)
504 {
505 	uint16_t i;
506 
507 	for (i = 0; i < num_buffers; i++) {
508 		/* enqueue shadow flush action aligned with batch num */
509 		if (!vq->shadow_used_idx)
510 			vq->shadow_aligned_idx = vq->last_used_idx &
511 				PACKED_BATCH_MASK;
512 		vq->shadow_used_packed[vq->shadow_used_idx].id  = id[i];
513 		vq->shadow_used_packed[vq->shadow_used_idx].len = len[i];
514 		vq->shadow_used_packed[vq->shadow_used_idx].count = count[i];
515 		vq->shadow_aligned_idx += count[i];
516 		vq->shadow_used_idx++;
517 	}
518 }
519 
520 static __rte_always_inline void
521 vhost_shadow_enqueue_single_packed(struct virtio_net *dev,
522 				   struct vhost_virtqueue *vq,
523 				   uint32_t *len,
524 				   uint16_t *id,
525 				   uint16_t *count,
526 				   uint16_t num_buffers)
527 {
528 	vhost_shadow_enqueue_packed(vq, len, id, count, num_buffers);
529 
530 	if (vq->shadow_aligned_idx >= PACKED_BATCH_SIZE) {
531 		do_data_copy_enqueue(dev, vq);
532 		vhost_flush_enqueue_shadow_packed(dev, vq);
533 	}
534 }
535 
536 /* avoid write operation when necessary, to lessen cache issues */
537 #define ASSIGN_UNLESS_EQUAL(var, val) do {	\
538 	if ((var) != (val))			\
539 		(var) = (val);			\
540 } while (0)
541 
542 static __rte_always_inline void
543 virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr *net_hdr)
544 {
545 	uint64_t csum_l4 = m_buf->ol_flags & RTE_MBUF_F_TX_L4_MASK;
546 
547 	if (m_buf->ol_flags & RTE_MBUF_F_TX_TCP_SEG)
548 		csum_l4 |= RTE_MBUF_F_TX_TCP_CKSUM;
549 
550 	if (csum_l4) {
551 		net_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
552 		net_hdr->csum_start = m_buf->l2_len + m_buf->l3_len;
553 
554 		switch (csum_l4) {
555 		case RTE_MBUF_F_TX_TCP_CKSUM:
556 			net_hdr->csum_offset = (offsetof(struct rte_tcp_hdr,
557 						cksum));
558 			break;
559 		case RTE_MBUF_F_TX_UDP_CKSUM:
560 			net_hdr->csum_offset = (offsetof(struct rte_udp_hdr,
561 						dgram_cksum));
562 			break;
563 		case RTE_MBUF_F_TX_SCTP_CKSUM:
564 			net_hdr->csum_offset = (offsetof(struct rte_sctp_hdr,
565 						cksum));
566 			break;
567 		}
568 	} else {
569 		ASSIGN_UNLESS_EQUAL(net_hdr->csum_start, 0);
570 		ASSIGN_UNLESS_EQUAL(net_hdr->csum_offset, 0);
571 		ASSIGN_UNLESS_EQUAL(net_hdr->flags, 0);
572 	}
573 
574 	/* IP cksum verification cannot be bypassed, then calculate here */
575 	if (m_buf->ol_flags & RTE_MBUF_F_TX_IP_CKSUM) {
576 		struct rte_ipv4_hdr *ipv4_hdr;
577 
578 		ipv4_hdr = rte_pktmbuf_mtod_offset(m_buf, struct rte_ipv4_hdr *,
579 						   m_buf->l2_len);
580 		ipv4_hdr->hdr_checksum = 0;
581 		ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
582 	}
583 
584 	if (m_buf->ol_flags & RTE_MBUF_F_TX_TCP_SEG) {
585 		if (m_buf->ol_flags & RTE_MBUF_F_TX_IPV4)
586 			net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
587 		else
588 			net_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
589 		net_hdr->gso_size = m_buf->tso_segsz;
590 		net_hdr->hdr_len = m_buf->l2_len + m_buf->l3_len
591 					+ m_buf->l4_len;
592 	} else if (m_buf->ol_flags & RTE_MBUF_F_TX_UDP_SEG) {
593 		net_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
594 		net_hdr->gso_size = m_buf->tso_segsz;
595 		net_hdr->hdr_len = m_buf->l2_len + m_buf->l3_len +
596 			m_buf->l4_len;
597 	} else {
598 		ASSIGN_UNLESS_EQUAL(net_hdr->gso_type, 0);
599 		ASSIGN_UNLESS_EQUAL(net_hdr->gso_size, 0);
600 		ASSIGN_UNLESS_EQUAL(net_hdr->hdr_len, 0);
601 	}
602 }
603 
604 static __rte_always_inline int
605 map_one_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
606 		struct buf_vector *buf_vec, uint16_t *vec_idx,
607 		uint64_t desc_iova, uint64_t desc_len, uint8_t perm)
608 {
609 	uint16_t vec_id = *vec_idx;
610 
611 	while (desc_len) {
612 		uint64_t desc_addr;
613 		uint64_t desc_chunck_len = desc_len;
614 
615 		if (unlikely(vec_id >= BUF_VECTOR_MAX))
616 			return -1;
617 
618 		desc_addr = vhost_iova_to_vva(dev, vq,
619 				desc_iova,
620 				&desc_chunck_len,
621 				perm);
622 		if (unlikely(!desc_addr))
623 			return -1;
624 
625 		rte_prefetch0((void *)(uintptr_t)desc_addr);
626 
627 		buf_vec[vec_id].buf_iova = desc_iova;
628 		buf_vec[vec_id].buf_addr = desc_addr;
629 		buf_vec[vec_id].buf_len  = desc_chunck_len;
630 
631 		desc_len -= desc_chunck_len;
632 		desc_iova += desc_chunck_len;
633 		vec_id++;
634 	}
635 	*vec_idx = vec_id;
636 
637 	return 0;
638 }
639 
640 static __rte_always_inline int
641 fill_vec_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
642 			 uint32_t avail_idx, uint16_t *vec_idx,
643 			 struct buf_vector *buf_vec, uint16_t *desc_chain_head,
644 			 uint32_t *desc_chain_len, uint8_t perm)
645 {
646 	uint16_t idx = vq->avail->ring[avail_idx & (vq->size - 1)];
647 	uint16_t vec_id = *vec_idx;
648 	uint32_t len    = 0;
649 	uint64_t dlen;
650 	uint32_t nr_descs = vq->size;
651 	uint32_t cnt    = 0;
652 	struct vring_desc *descs = vq->desc;
653 	struct vring_desc *idesc = NULL;
654 
655 	if (unlikely(idx >= vq->size))
656 		return -1;
657 
658 	*desc_chain_head = idx;
659 
660 	if (vq->desc[idx].flags & VRING_DESC_F_INDIRECT) {
661 		dlen = vq->desc[idx].len;
662 		nr_descs = dlen / sizeof(struct vring_desc);
663 		if (unlikely(nr_descs > vq->size))
664 			return -1;
665 
666 		descs = (struct vring_desc *)(uintptr_t)
667 			vhost_iova_to_vva(dev, vq, vq->desc[idx].addr,
668 						&dlen,
669 						VHOST_ACCESS_RO);
670 		if (unlikely(!descs))
671 			return -1;
672 
673 		if (unlikely(dlen < vq->desc[idx].len)) {
674 			/*
675 			 * The indirect desc table is not contiguous
676 			 * in process VA space, we have to copy it.
677 			 */
678 			idesc = vhost_alloc_copy_ind_table(dev, vq,
679 					vq->desc[idx].addr, vq->desc[idx].len);
680 			if (unlikely(!idesc))
681 				return -1;
682 
683 			descs = idesc;
684 		}
685 
686 		idx = 0;
687 	}
688 
689 	while (1) {
690 		if (unlikely(idx >= nr_descs || cnt++ >= nr_descs)) {
691 			free_ind_table(idesc);
692 			return -1;
693 		}
694 
695 		dlen = descs[idx].len;
696 		len += dlen;
697 
698 		if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id,
699 						descs[idx].addr, dlen,
700 						perm))) {
701 			free_ind_table(idesc);
702 			return -1;
703 		}
704 
705 		if ((descs[idx].flags & VRING_DESC_F_NEXT) == 0)
706 			break;
707 
708 		idx = descs[idx].next;
709 	}
710 
711 	*desc_chain_len = len;
712 	*vec_idx = vec_id;
713 
714 	if (unlikely(!!idesc))
715 		free_ind_table(idesc);
716 
717 	return 0;
718 }
719 
720 /*
721  * Returns -1 on fail, 0 on success
722  */
723 static inline int
724 reserve_avail_buf_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
725 				uint32_t size, struct buf_vector *buf_vec,
726 				uint16_t *num_buffers, uint16_t avail_head,
727 				uint16_t *nr_vec)
728 {
729 	uint16_t cur_idx;
730 	uint16_t vec_idx = 0;
731 	uint16_t max_tries, tries = 0;
732 
733 	uint16_t head_idx = 0;
734 	uint32_t len = 0;
735 
736 	*num_buffers = 0;
737 	cur_idx  = vq->last_avail_idx;
738 
739 	if (rxvq_is_mergeable(dev))
740 		max_tries = vq->size - 1;
741 	else
742 		max_tries = 1;
743 
744 	while (size > 0) {
745 		if (unlikely(cur_idx == avail_head))
746 			return -1;
747 		/*
748 		 * if we tried all available ring items, and still
749 		 * can't get enough buf, it means something abnormal
750 		 * happened.
751 		 */
752 		if (unlikely(++tries > max_tries))
753 			return -1;
754 
755 		if (unlikely(fill_vec_buf_split(dev, vq, cur_idx,
756 						&vec_idx, buf_vec,
757 						&head_idx, &len,
758 						VHOST_ACCESS_RW) < 0))
759 			return -1;
760 		len = RTE_MIN(len, size);
761 		update_shadow_used_ring_split(vq, head_idx, len);
762 		size -= len;
763 
764 		cur_idx++;
765 		*num_buffers += 1;
766 	}
767 
768 	*nr_vec = vec_idx;
769 
770 	return 0;
771 }
772 
773 static __rte_always_inline int
774 fill_vec_buf_packed_indirect(struct virtio_net *dev,
775 			struct vhost_virtqueue *vq,
776 			struct vring_packed_desc *desc, uint16_t *vec_idx,
777 			struct buf_vector *buf_vec, uint32_t *len, uint8_t perm)
778 {
779 	uint16_t i;
780 	uint32_t nr_descs;
781 	uint16_t vec_id = *vec_idx;
782 	uint64_t dlen;
783 	struct vring_packed_desc *descs, *idescs = NULL;
784 
785 	dlen = desc->len;
786 	descs = (struct vring_packed_desc *)(uintptr_t)
787 		vhost_iova_to_vva(dev, vq, desc->addr, &dlen, VHOST_ACCESS_RO);
788 	if (unlikely(!descs))
789 		return -1;
790 
791 	if (unlikely(dlen < desc->len)) {
792 		/*
793 		 * The indirect desc table is not contiguous
794 		 * in process VA space, we have to copy it.
795 		 */
796 		idescs = vhost_alloc_copy_ind_table(dev,
797 				vq, desc->addr, desc->len);
798 		if (unlikely(!idescs))
799 			return -1;
800 
801 		descs = idescs;
802 	}
803 
804 	nr_descs =  desc->len / sizeof(struct vring_packed_desc);
805 	if (unlikely(nr_descs >= vq->size)) {
806 		free_ind_table(idescs);
807 		return -1;
808 	}
809 
810 	for (i = 0; i < nr_descs; i++) {
811 		if (unlikely(vec_id >= BUF_VECTOR_MAX)) {
812 			free_ind_table(idescs);
813 			return -1;
814 		}
815 
816 		dlen = descs[i].len;
817 		*len += dlen;
818 		if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id,
819 						descs[i].addr, dlen,
820 						perm)))
821 			return -1;
822 	}
823 	*vec_idx = vec_id;
824 
825 	if (unlikely(!!idescs))
826 		free_ind_table(idescs);
827 
828 	return 0;
829 }
830 
831 static __rte_always_inline int
832 fill_vec_buf_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
833 				uint16_t avail_idx, uint16_t *desc_count,
834 				struct buf_vector *buf_vec, uint16_t *vec_idx,
835 				uint16_t *buf_id, uint32_t *len, uint8_t perm)
836 {
837 	bool wrap_counter = vq->avail_wrap_counter;
838 	struct vring_packed_desc *descs = vq->desc_packed;
839 	uint16_t vec_id = *vec_idx;
840 	uint64_t dlen;
841 
842 	if (avail_idx < vq->last_avail_idx)
843 		wrap_counter ^= 1;
844 
845 	/*
846 	 * Perform a load-acquire barrier in desc_is_avail to
847 	 * enforce the ordering between desc flags and desc
848 	 * content.
849 	 */
850 	if (unlikely(!desc_is_avail(&descs[avail_idx], wrap_counter)))
851 		return -1;
852 
853 	*desc_count = 0;
854 	*len = 0;
855 
856 	while (1) {
857 		if (unlikely(vec_id >= BUF_VECTOR_MAX))
858 			return -1;
859 
860 		if (unlikely(*desc_count >= vq->size))
861 			return -1;
862 
863 		*desc_count += 1;
864 		*buf_id = descs[avail_idx].id;
865 
866 		if (descs[avail_idx].flags & VRING_DESC_F_INDIRECT) {
867 			if (unlikely(fill_vec_buf_packed_indirect(dev, vq,
868 							&descs[avail_idx],
869 							&vec_id, buf_vec,
870 							len, perm) < 0))
871 				return -1;
872 		} else {
873 			dlen = descs[avail_idx].len;
874 			*len += dlen;
875 
876 			if (unlikely(map_one_desc(dev, vq, buf_vec, &vec_id,
877 							descs[avail_idx].addr,
878 							dlen,
879 							perm)))
880 				return -1;
881 		}
882 
883 		if ((descs[avail_idx].flags & VRING_DESC_F_NEXT) == 0)
884 			break;
885 
886 		if (++avail_idx >= vq->size) {
887 			avail_idx -= vq->size;
888 			wrap_counter ^= 1;
889 		}
890 	}
891 
892 	*vec_idx = vec_id;
893 
894 	return 0;
895 }
896 
897 static __rte_noinline void
898 copy_vnet_hdr_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
899 		struct buf_vector *buf_vec,
900 		struct virtio_net_hdr_mrg_rxbuf *hdr)
901 {
902 	uint64_t len;
903 	uint64_t remain = dev->vhost_hlen;
904 	uint64_t src = (uint64_t)(uintptr_t)hdr, dst;
905 	uint64_t iova = buf_vec->buf_iova;
906 
907 	while (remain) {
908 		len = RTE_MIN(remain,
909 				buf_vec->buf_len);
910 		dst = buf_vec->buf_addr;
911 		rte_memcpy((void *)(uintptr_t)dst,
912 				(void *)(uintptr_t)src,
913 				len);
914 
915 		PRINT_PACKET(dev, (uintptr_t)dst,
916 				(uint32_t)len, 0);
917 		vhost_log_cache_write_iova(dev, vq,
918 				iova, len);
919 
920 		remain -= len;
921 		iova += len;
922 		src += len;
923 		buf_vec++;
924 	}
925 }
926 
927 static __rte_always_inline int
928 async_iter_initialize(struct virtio_net *dev, struct vhost_async *async)
929 {
930 	struct vhost_iov_iter *iter;
931 
932 	if (unlikely(async->iovec_idx >= VHOST_MAX_ASYNC_VEC)) {
933 		VHOST_LOG_DATA(ERR, "(%s) no more async iovec available\n", dev->ifname);
934 		return -1;
935 	}
936 
937 	iter = async->iov_iter + async->iter_idx;
938 	iter->iov = async->iovec + async->iovec_idx;
939 	iter->nr_segs = 0;
940 
941 	return 0;
942 }
943 
944 static __rte_always_inline int
945 async_iter_add_iovec(struct virtio_net *dev, struct vhost_async *async,
946 		void *src, void *dst, size_t len)
947 {
948 	struct vhost_iov_iter *iter;
949 	struct vhost_iovec *iovec;
950 
951 	if (unlikely(async->iovec_idx >= VHOST_MAX_ASYNC_VEC)) {
952 		static bool vhost_max_async_vec_log;
953 
954 		if (!vhost_max_async_vec_log) {
955 			VHOST_LOG_DATA(ERR, "(%s) no more async iovec available\n", dev->ifname);
956 			vhost_max_async_vec_log = true;
957 		}
958 
959 		return -1;
960 	}
961 
962 	iter = async->iov_iter + async->iter_idx;
963 	iovec = async->iovec + async->iovec_idx;
964 
965 	iovec->src_addr = src;
966 	iovec->dst_addr = dst;
967 	iovec->len = len;
968 
969 	iter->nr_segs++;
970 	async->iovec_idx++;
971 
972 	return 0;
973 }
974 
975 static __rte_always_inline void
976 async_iter_finalize(struct vhost_async *async)
977 {
978 	async->iter_idx++;
979 }
980 
981 static __rte_always_inline void
982 async_iter_cancel(struct vhost_async *async)
983 {
984 	struct vhost_iov_iter *iter;
985 
986 	iter = async->iov_iter + async->iter_idx;
987 	async->iovec_idx -= iter->nr_segs;
988 	iter->nr_segs = 0;
989 	iter->iov = NULL;
990 }
991 
992 static __rte_always_inline void
993 async_iter_reset(struct vhost_async *async)
994 {
995 	async->iter_idx = 0;
996 	async->iovec_idx = 0;
997 }
998 
999 static __rte_always_inline int
1000 async_mbuf_to_desc_seg(struct virtio_net *dev, struct vhost_virtqueue *vq,
1001 		struct rte_mbuf *m, uint32_t mbuf_offset,
1002 		uint64_t buf_iova, uint32_t cpy_len)
1003 {
1004 	struct vhost_async *async = vq->async;
1005 	uint64_t mapped_len;
1006 	uint32_t buf_offset = 0;
1007 	void *hpa;
1008 
1009 	while (cpy_len) {
1010 		hpa = (void *)(uintptr_t)gpa_to_first_hpa(dev,
1011 				buf_iova + buf_offset, cpy_len, &mapped_len);
1012 		if (unlikely(!hpa)) {
1013 			VHOST_LOG_DATA(ERR, "(%s) %s: failed to get hpa.\n", dev->ifname, __func__);
1014 			return -1;
1015 		}
1016 
1017 		if (unlikely(async_iter_add_iovec(dev, async,
1018 						(void *)(uintptr_t)rte_pktmbuf_iova_offset(m,
1019 							mbuf_offset),
1020 						hpa, (size_t)mapped_len)))
1021 			return -1;
1022 
1023 		cpy_len -= (uint32_t)mapped_len;
1024 		mbuf_offset += (uint32_t)mapped_len;
1025 		buf_offset += (uint32_t)mapped_len;
1026 	}
1027 
1028 	return 0;
1029 }
1030 
1031 static __rte_always_inline void
1032 sync_mbuf_to_desc_seg(struct virtio_net *dev, struct vhost_virtqueue *vq,
1033 		struct rte_mbuf *m, uint32_t mbuf_offset,
1034 		uint64_t buf_addr, uint64_t buf_iova, uint32_t cpy_len)
1035 {
1036 	struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
1037 
1038 	if (likely(cpy_len > MAX_BATCH_LEN || vq->batch_copy_nb_elems >= vq->size)) {
1039 		rte_memcpy((void *)((uintptr_t)(buf_addr)),
1040 				rte_pktmbuf_mtod_offset(m, void *, mbuf_offset),
1041 				cpy_len);
1042 		vhost_log_cache_write_iova(dev, vq, buf_iova, cpy_len);
1043 		PRINT_PACKET(dev, (uintptr_t)(buf_addr), cpy_len, 0);
1044 	} else {
1045 		batch_copy[vq->batch_copy_nb_elems].dst =
1046 			(void *)((uintptr_t)(buf_addr));
1047 		batch_copy[vq->batch_copy_nb_elems].src =
1048 			rte_pktmbuf_mtod_offset(m, void *, mbuf_offset);
1049 		batch_copy[vq->batch_copy_nb_elems].log_addr = buf_iova;
1050 		batch_copy[vq->batch_copy_nb_elems].len = cpy_len;
1051 		vq->batch_copy_nb_elems++;
1052 	}
1053 }
1054 
1055 static __rte_always_inline int
1056 mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq,
1057 		struct rte_mbuf *m, struct buf_vector *buf_vec,
1058 		uint16_t nr_vec, uint16_t num_buffers, bool is_async)
1059 {
1060 	uint32_t vec_idx = 0;
1061 	uint32_t mbuf_offset, mbuf_avail;
1062 	uint32_t buf_offset, buf_avail;
1063 	uint64_t buf_addr, buf_iova, buf_len;
1064 	uint32_t cpy_len;
1065 	uint64_t hdr_addr;
1066 	struct rte_mbuf *hdr_mbuf;
1067 	struct virtio_net_hdr_mrg_rxbuf tmp_hdr, *hdr = NULL;
1068 	struct vhost_async *async = vq->async;
1069 
1070 	if (unlikely(m == NULL))
1071 		return -1;
1072 
1073 	buf_addr = buf_vec[vec_idx].buf_addr;
1074 	buf_iova = buf_vec[vec_idx].buf_iova;
1075 	buf_len = buf_vec[vec_idx].buf_len;
1076 
1077 	if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1))
1078 		return -1;
1079 
1080 	hdr_mbuf = m;
1081 	hdr_addr = buf_addr;
1082 	if (unlikely(buf_len < dev->vhost_hlen)) {
1083 		memset(&tmp_hdr, 0, sizeof(struct virtio_net_hdr_mrg_rxbuf));
1084 		hdr = &tmp_hdr;
1085 	} else
1086 		hdr = (struct virtio_net_hdr_mrg_rxbuf *)(uintptr_t)hdr_addr;
1087 
1088 	VHOST_LOG_DATA(DEBUG, "(%s) RX: num merge buffers %d\n",
1089 		dev->ifname, num_buffers);
1090 
1091 	if (unlikely(buf_len < dev->vhost_hlen)) {
1092 		buf_offset = dev->vhost_hlen - buf_len;
1093 		vec_idx++;
1094 		buf_addr = buf_vec[vec_idx].buf_addr;
1095 		buf_iova = buf_vec[vec_idx].buf_iova;
1096 		buf_len = buf_vec[vec_idx].buf_len;
1097 		buf_avail = buf_len - buf_offset;
1098 	} else {
1099 		buf_offset = dev->vhost_hlen;
1100 		buf_avail = buf_len - dev->vhost_hlen;
1101 	}
1102 
1103 	mbuf_avail  = rte_pktmbuf_data_len(m);
1104 	mbuf_offset = 0;
1105 
1106 	if (is_async) {
1107 		if (async_iter_initialize(dev, async))
1108 			return -1;
1109 	}
1110 
1111 	while (mbuf_avail != 0 || m->next != NULL) {
1112 		/* done with current buf, get the next one */
1113 		if (buf_avail == 0) {
1114 			vec_idx++;
1115 			if (unlikely(vec_idx >= nr_vec))
1116 				goto error;
1117 
1118 			buf_addr = buf_vec[vec_idx].buf_addr;
1119 			buf_iova = buf_vec[vec_idx].buf_iova;
1120 			buf_len = buf_vec[vec_idx].buf_len;
1121 
1122 			buf_offset = 0;
1123 			buf_avail  = buf_len;
1124 		}
1125 
1126 		/* done with current mbuf, get the next one */
1127 		if (mbuf_avail == 0) {
1128 			m = m->next;
1129 
1130 			mbuf_offset = 0;
1131 			mbuf_avail  = rte_pktmbuf_data_len(m);
1132 		}
1133 
1134 		if (hdr_addr) {
1135 			virtio_enqueue_offload(hdr_mbuf, &hdr->hdr);
1136 			if (rxvq_is_mergeable(dev))
1137 				ASSIGN_UNLESS_EQUAL(hdr->num_buffers,
1138 						num_buffers);
1139 
1140 			if (unlikely(hdr == &tmp_hdr)) {
1141 				copy_vnet_hdr_to_desc(dev, vq, buf_vec, hdr);
1142 			} else {
1143 				PRINT_PACKET(dev, (uintptr_t)hdr_addr,
1144 						dev->vhost_hlen, 0);
1145 				vhost_log_cache_write_iova(dev, vq,
1146 						buf_vec[0].buf_iova,
1147 						dev->vhost_hlen);
1148 			}
1149 
1150 			hdr_addr = 0;
1151 		}
1152 
1153 		cpy_len = RTE_MIN(buf_avail, mbuf_avail);
1154 
1155 		if (is_async) {
1156 			if (async_mbuf_to_desc_seg(dev, vq, m, mbuf_offset,
1157 						buf_iova + buf_offset, cpy_len) < 0)
1158 				goto error;
1159 		} else {
1160 			sync_mbuf_to_desc_seg(dev, vq, m, mbuf_offset,
1161 					buf_addr + buf_offset,
1162 					buf_iova + buf_offset, cpy_len);
1163 		}
1164 
1165 		mbuf_avail  -= cpy_len;
1166 		mbuf_offset += cpy_len;
1167 		buf_avail  -= cpy_len;
1168 		buf_offset += cpy_len;
1169 	}
1170 
1171 	if (is_async)
1172 		async_iter_finalize(async);
1173 
1174 	return 0;
1175 error:
1176 	if (is_async)
1177 		async_iter_cancel(async);
1178 
1179 	return -1;
1180 }
1181 
1182 static __rte_always_inline int
1183 vhost_enqueue_single_packed(struct virtio_net *dev,
1184 			    struct vhost_virtqueue *vq,
1185 			    struct rte_mbuf *pkt,
1186 			    struct buf_vector *buf_vec,
1187 			    uint16_t *nr_descs)
1188 {
1189 	uint16_t nr_vec = 0;
1190 	uint16_t avail_idx = vq->last_avail_idx;
1191 	uint16_t max_tries, tries = 0;
1192 	uint16_t buf_id = 0;
1193 	uint32_t len = 0;
1194 	uint16_t desc_count;
1195 	uint32_t size = pkt->pkt_len + sizeof(struct virtio_net_hdr_mrg_rxbuf);
1196 	uint16_t num_buffers = 0;
1197 	uint32_t buffer_len[vq->size];
1198 	uint16_t buffer_buf_id[vq->size];
1199 	uint16_t buffer_desc_count[vq->size];
1200 
1201 	if (rxvq_is_mergeable(dev))
1202 		max_tries = vq->size - 1;
1203 	else
1204 		max_tries = 1;
1205 
1206 	while (size > 0) {
1207 		/*
1208 		 * if we tried all available ring items, and still
1209 		 * can't get enough buf, it means something abnormal
1210 		 * happened.
1211 		 */
1212 		if (unlikely(++tries > max_tries))
1213 			return -1;
1214 
1215 		if (unlikely(fill_vec_buf_packed(dev, vq,
1216 						avail_idx, &desc_count,
1217 						buf_vec, &nr_vec,
1218 						&buf_id, &len,
1219 						VHOST_ACCESS_RW) < 0))
1220 			return -1;
1221 
1222 		len = RTE_MIN(len, size);
1223 		size -= len;
1224 
1225 		buffer_len[num_buffers] = len;
1226 		buffer_buf_id[num_buffers] = buf_id;
1227 		buffer_desc_count[num_buffers] = desc_count;
1228 		num_buffers += 1;
1229 
1230 		*nr_descs += desc_count;
1231 		avail_idx += desc_count;
1232 		if (avail_idx >= vq->size)
1233 			avail_idx -= vq->size;
1234 	}
1235 
1236 	if (mbuf_to_desc(dev, vq, pkt, buf_vec, nr_vec, num_buffers, false) < 0)
1237 		return -1;
1238 
1239 	vhost_shadow_enqueue_single_packed(dev, vq, buffer_len, buffer_buf_id,
1240 					   buffer_desc_count, num_buffers);
1241 
1242 	return 0;
1243 }
1244 
1245 static __rte_noinline uint32_t
1246 virtio_dev_rx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
1247 	struct rte_mbuf **pkts, uint32_t count)
1248 {
1249 	uint32_t pkt_idx = 0;
1250 	uint16_t num_buffers;
1251 	struct buf_vector buf_vec[BUF_VECTOR_MAX];
1252 	uint16_t avail_head;
1253 
1254 	/*
1255 	 * The ordering between avail index and
1256 	 * desc reads needs to be enforced.
1257 	 */
1258 	avail_head = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE);
1259 
1260 	rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
1261 
1262 	for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
1263 		uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
1264 		uint16_t nr_vec = 0;
1265 
1266 		if (unlikely(reserve_avail_buf_split(dev, vq,
1267 						pkt_len, buf_vec, &num_buffers,
1268 						avail_head, &nr_vec) < 0)) {
1269 			VHOST_LOG_DATA(DEBUG,
1270 				"(%s) failed to get enough desc from vring\n",
1271 				dev->ifname);
1272 			vq->shadow_used_idx -= num_buffers;
1273 			break;
1274 		}
1275 
1276 		VHOST_LOG_DATA(DEBUG, "(%s) current index %d | end index %d\n",
1277 			dev->ifname, vq->last_avail_idx,
1278 			vq->last_avail_idx + num_buffers);
1279 
1280 		if (mbuf_to_desc(dev, vq, pkts[pkt_idx], buf_vec, nr_vec,
1281 					num_buffers, false) < 0) {
1282 			vq->shadow_used_idx -= num_buffers;
1283 			break;
1284 		}
1285 
1286 		vq->last_avail_idx += num_buffers;
1287 	}
1288 
1289 	do_data_copy_enqueue(dev, vq);
1290 
1291 	if (likely(vq->shadow_used_idx)) {
1292 		flush_shadow_used_ring_split(dev, vq);
1293 		vhost_vring_call_split(dev, vq);
1294 	}
1295 
1296 	return pkt_idx;
1297 }
1298 
1299 static __rte_always_inline int
1300 virtio_dev_rx_sync_batch_check(struct virtio_net *dev,
1301 			   struct vhost_virtqueue *vq,
1302 			   struct rte_mbuf **pkts,
1303 			   uint64_t *desc_addrs,
1304 			   uint64_t *lens)
1305 {
1306 	bool wrap_counter = vq->avail_wrap_counter;
1307 	struct vring_packed_desc *descs = vq->desc_packed;
1308 	uint16_t avail_idx = vq->last_avail_idx;
1309 	uint32_t buf_offset = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1310 	uint16_t i;
1311 
1312 	if (unlikely(avail_idx & PACKED_BATCH_MASK))
1313 		return -1;
1314 
1315 	if (unlikely((avail_idx + PACKED_BATCH_SIZE) > vq->size))
1316 		return -1;
1317 
1318 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
1319 		if (unlikely(pkts[i]->next != NULL))
1320 			return -1;
1321 		if (unlikely(!desc_is_avail(&descs[avail_idx + i],
1322 					    wrap_counter)))
1323 			return -1;
1324 	}
1325 
1326 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
1327 		lens[i] = descs[avail_idx + i].len;
1328 
1329 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
1330 		if (unlikely(pkts[i]->pkt_len > (lens[i] - buf_offset)))
1331 			return -1;
1332 	}
1333 
1334 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
1335 		desc_addrs[i] = vhost_iova_to_vva(dev, vq,
1336 						  descs[avail_idx + i].addr,
1337 						  &lens[i],
1338 						  VHOST_ACCESS_RW);
1339 
1340 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
1341 		if (unlikely(!desc_addrs[i]))
1342 			return -1;
1343 		if (unlikely(lens[i] != descs[avail_idx + i].len))
1344 			return -1;
1345 	}
1346 
1347 	return 0;
1348 }
1349 
1350 static __rte_always_inline void
1351 virtio_dev_rx_batch_packed_copy(struct virtio_net *dev,
1352 			   struct vhost_virtqueue *vq,
1353 			   struct rte_mbuf **pkts,
1354 			   uint64_t *desc_addrs,
1355 			   uint64_t *lens)
1356 {
1357 	uint32_t buf_offset = sizeof(struct virtio_net_hdr_mrg_rxbuf);
1358 	struct virtio_net_hdr_mrg_rxbuf *hdrs[PACKED_BATCH_SIZE];
1359 	struct vring_packed_desc *descs = vq->desc_packed;
1360 	uint16_t avail_idx = vq->last_avail_idx;
1361 	uint16_t ids[PACKED_BATCH_SIZE];
1362 	uint16_t i;
1363 
1364 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
1365 		rte_prefetch0((void *)(uintptr_t)desc_addrs[i]);
1366 		hdrs[i] = (struct virtio_net_hdr_mrg_rxbuf *)
1367 					(uintptr_t)desc_addrs[i];
1368 		lens[i] = pkts[i]->pkt_len +
1369 			sizeof(struct virtio_net_hdr_mrg_rxbuf);
1370 	}
1371 
1372 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
1373 		virtio_enqueue_offload(pkts[i], &hdrs[i]->hdr);
1374 
1375 	vq_inc_last_avail_packed(vq, PACKED_BATCH_SIZE);
1376 
1377 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
1378 		rte_memcpy((void *)(uintptr_t)(desc_addrs[i] + buf_offset),
1379 			   rte_pktmbuf_mtod_offset(pkts[i], void *, 0),
1380 			   pkts[i]->pkt_len);
1381 	}
1382 
1383 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
1384 		vhost_log_cache_write_iova(dev, vq, descs[avail_idx + i].addr,
1385 					   lens[i]);
1386 
1387 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
1388 		ids[i] = descs[avail_idx + i].id;
1389 
1390 	vhost_flush_enqueue_batch_packed(dev, vq, lens, ids);
1391 }
1392 
1393 static __rte_always_inline int
1394 virtio_dev_rx_sync_batch_packed(struct virtio_net *dev,
1395 			   struct vhost_virtqueue *vq,
1396 			   struct rte_mbuf **pkts)
1397 {
1398 	uint64_t desc_addrs[PACKED_BATCH_SIZE];
1399 	uint64_t lens[PACKED_BATCH_SIZE];
1400 
1401 	if (virtio_dev_rx_sync_batch_check(dev, vq, pkts, desc_addrs, lens) == -1)
1402 		return -1;
1403 
1404 	if (vq->shadow_used_idx) {
1405 		do_data_copy_enqueue(dev, vq);
1406 		vhost_flush_enqueue_shadow_packed(dev, vq);
1407 	}
1408 
1409 	virtio_dev_rx_batch_packed_copy(dev, vq, pkts, desc_addrs, lens);
1410 
1411 	return 0;
1412 }
1413 
1414 static __rte_always_inline int16_t
1415 virtio_dev_rx_single_packed(struct virtio_net *dev,
1416 			    struct vhost_virtqueue *vq,
1417 			    struct rte_mbuf *pkt)
1418 {
1419 	struct buf_vector buf_vec[BUF_VECTOR_MAX];
1420 	uint16_t nr_descs = 0;
1421 
1422 	if (unlikely(vhost_enqueue_single_packed(dev, vq, pkt, buf_vec,
1423 						 &nr_descs) < 0)) {
1424 		VHOST_LOG_DATA(DEBUG, "(%s) failed to get enough desc from vring\n",
1425 				dev->ifname);
1426 		return -1;
1427 	}
1428 
1429 	VHOST_LOG_DATA(DEBUG, "(%s) current index %d | end index %d\n",
1430 			dev->ifname, vq->last_avail_idx,
1431 			vq->last_avail_idx + nr_descs);
1432 
1433 	vq_inc_last_avail_packed(vq, nr_descs);
1434 
1435 	return 0;
1436 }
1437 
1438 static __rte_noinline uint32_t
1439 virtio_dev_rx_packed(struct virtio_net *dev,
1440 		     struct vhost_virtqueue *__rte_restrict vq,
1441 		     struct rte_mbuf **__rte_restrict pkts,
1442 		     uint32_t count)
1443 {
1444 	uint32_t pkt_idx = 0;
1445 
1446 	do {
1447 		rte_prefetch0(&vq->desc_packed[vq->last_avail_idx]);
1448 
1449 		if (count - pkt_idx >= PACKED_BATCH_SIZE) {
1450 			if (!virtio_dev_rx_sync_batch_packed(dev, vq,
1451 							&pkts[pkt_idx])) {
1452 				pkt_idx += PACKED_BATCH_SIZE;
1453 				continue;
1454 			}
1455 		}
1456 
1457 		if (virtio_dev_rx_single_packed(dev, vq, pkts[pkt_idx]))
1458 			break;
1459 		pkt_idx++;
1460 
1461 	} while (pkt_idx < count);
1462 
1463 	if (vq->shadow_used_idx) {
1464 		do_data_copy_enqueue(dev, vq);
1465 		vhost_flush_enqueue_shadow_packed(dev, vq);
1466 	}
1467 
1468 	if (pkt_idx)
1469 		vhost_vring_call_packed(dev, vq);
1470 
1471 	return pkt_idx;
1472 }
1473 
1474 static __rte_always_inline uint32_t
1475 virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
1476 	struct rte_mbuf **pkts, uint32_t count)
1477 {
1478 	struct vhost_virtqueue *vq;
1479 	uint32_t nb_tx = 0;
1480 
1481 	VHOST_LOG_DATA(DEBUG, "(%s) %s\n", dev->ifname, __func__);
1482 	if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
1483 		VHOST_LOG_DATA(ERR, "(%s) %s: invalid virtqueue idx %d.\n",
1484 			dev->ifname, __func__, queue_id);
1485 		return 0;
1486 	}
1487 
1488 	vq = dev->virtqueue[queue_id];
1489 
1490 	rte_spinlock_lock(&vq->access_lock);
1491 
1492 	if (unlikely(!vq->enabled))
1493 		goto out_access_unlock;
1494 
1495 	if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
1496 		vhost_user_iotlb_rd_lock(vq);
1497 
1498 	if (unlikely(!vq->access_ok))
1499 		if (unlikely(vring_translate(dev, vq) < 0))
1500 			goto out;
1501 
1502 	count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
1503 	if (count == 0)
1504 		goto out;
1505 
1506 	if (vq_is_packed(dev))
1507 		nb_tx = virtio_dev_rx_packed(dev, vq, pkts, count);
1508 	else
1509 		nb_tx = virtio_dev_rx_split(dev, vq, pkts, count);
1510 
1511 out:
1512 	if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
1513 		vhost_user_iotlb_rd_unlock(vq);
1514 
1515 out_access_unlock:
1516 	rte_spinlock_unlock(&vq->access_lock);
1517 
1518 	return nb_tx;
1519 }
1520 
1521 uint16_t
1522 rte_vhost_enqueue_burst(int vid, uint16_t queue_id,
1523 	struct rte_mbuf **__rte_restrict pkts, uint16_t count)
1524 {
1525 	struct virtio_net *dev = get_device(vid);
1526 
1527 	if (!dev)
1528 		return 0;
1529 
1530 	if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
1531 		VHOST_LOG_DATA(ERR, "(%s) %s: built-in vhost net backend is disabled.\n",
1532 			dev->ifname, __func__);
1533 		return 0;
1534 	}
1535 
1536 	return virtio_dev_rx(dev, queue_id, pkts, count);
1537 }
1538 
1539 static __rte_always_inline uint16_t
1540 async_get_first_inflight_pkt_idx(struct vhost_virtqueue *vq)
1541 {
1542 	struct vhost_async *async = vq->async;
1543 
1544 	if (async->pkts_idx >= async->pkts_inflight_n)
1545 		return async->pkts_idx - async->pkts_inflight_n;
1546 	else
1547 		return vq->size - async->pkts_inflight_n + async->pkts_idx;
1548 }
1549 
1550 static __rte_always_inline void
1551 store_dma_desc_info_split(struct vring_used_elem *s_ring, struct vring_used_elem *d_ring,
1552 		uint16_t ring_size, uint16_t s_idx, uint16_t d_idx, uint16_t count)
1553 {
1554 	size_t elem_size = sizeof(struct vring_used_elem);
1555 
1556 	if (d_idx + count <= ring_size) {
1557 		rte_memcpy(d_ring + d_idx, s_ring + s_idx, count * elem_size);
1558 	} else {
1559 		uint16_t size = ring_size - d_idx;
1560 
1561 		rte_memcpy(d_ring + d_idx, s_ring + s_idx, size * elem_size);
1562 		rte_memcpy(d_ring, s_ring + s_idx + size, (count - size) * elem_size);
1563 	}
1564 }
1565 
1566 static __rte_always_inline void
1567 store_dma_desc_info_packed(struct vring_used_elem_packed *s_ring,
1568 		struct vring_used_elem_packed *d_ring,
1569 		uint16_t ring_size, uint16_t s_idx, uint16_t d_idx, uint16_t count)
1570 {
1571 	size_t elem_size = sizeof(struct vring_used_elem_packed);
1572 
1573 	if (d_idx + count <= ring_size) {
1574 		rte_memcpy(d_ring + d_idx, s_ring + s_idx, count * elem_size);
1575 	} else {
1576 		uint16_t size = ring_size - d_idx;
1577 
1578 		rte_memcpy(d_ring + d_idx, s_ring + s_idx, size * elem_size);
1579 		rte_memcpy(d_ring, s_ring + s_idx + size, (count - size) * elem_size);
1580 	}
1581 }
1582 
1583 static __rte_noinline uint32_t
1584 virtio_dev_rx_async_submit_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
1585 		uint16_t queue_id, struct rte_mbuf **pkts, uint32_t count,
1586 		int16_t dma_id, uint16_t vchan_id)
1587 {
1588 	struct buf_vector buf_vec[BUF_VECTOR_MAX];
1589 	uint32_t pkt_idx = 0;
1590 	uint16_t num_buffers;
1591 	uint16_t avail_head;
1592 
1593 	struct vhost_async *async = vq->async;
1594 	struct async_inflight_info *pkts_info = async->pkts_info;
1595 	uint32_t pkt_err = 0;
1596 	uint16_t n_xfer;
1597 	uint16_t slot_idx = 0;
1598 
1599 	/*
1600 	 * The ordering between avail index and desc reads need to be enforced.
1601 	 */
1602 	avail_head = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE);
1603 
1604 	rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
1605 
1606 	async_iter_reset(async);
1607 
1608 	for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {
1609 		uint32_t pkt_len = pkts[pkt_idx]->pkt_len + dev->vhost_hlen;
1610 		uint16_t nr_vec = 0;
1611 
1612 		if (unlikely(reserve_avail_buf_split(dev, vq, pkt_len, buf_vec,
1613 						&num_buffers, avail_head, &nr_vec) < 0)) {
1614 			VHOST_LOG_DATA(DEBUG, "(%s) failed to get enough desc from vring\n",
1615 					dev->ifname);
1616 			vq->shadow_used_idx -= num_buffers;
1617 			break;
1618 		}
1619 
1620 		VHOST_LOG_DATA(DEBUG, "(%s) current index %d | end index %d\n",
1621 			dev->ifname, vq->last_avail_idx, vq->last_avail_idx + num_buffers);
1622 
1623 		if (mbuf_to_desc(dev, vq, pkts[pkt_idx], buf_vec, nr_vec, num_buffers, true) < 0) {
1624 			vq->shadow_used_idx -= num_buffers;
1625 			break;
1626 		}
1627 
1628 		slot_idx = (async->pkts_idx + pkt_idx) & (vq->size - 1);
1629 		pkts_info[slot_idx].descs = num_buffers;
1630 		pkts_info[slot_idx].mbuf = pkts[pkt_idx];
1631 
1632 		vq->last_avail_idx += num_buffers;
1633 	}
1634 
1635 	if (unlikely(pkt_idx == 0))
1636 		return 0;
1637 
1638 	n_xfer = vhost_async_dma_transfer(dev, vq, dma_id, vchan_id, async->pkts_idx,
1639 			async->iov_iter, pkt_idx);
1640 
1641 	pkt_err = pkt_idx - n_xfer;
1642 	if (unlikely(pkt_err)) {
1643 		uint16_t num_descs = 0;
1644 
1645 		VHOST_LOG_DATA(DEBUG, "(%s) %s: failed to transfer %u packets for queue %u.\n",
1646 				dev->ifname, __func__, pkt_err, queue_id);
1647 
1648 		/* update number of completed packets */
1649 		pkt_idx = n_xfer;
1650 
1651 		/* calculate the sum of descriptors to revert */
1652 		while (pkt_err-- > 0) {
1653 			num_descs += pkts_info[slot_idx & (vq->size - 1)].descs;
1654 			slot_idx--;
1655 		}
1656 
1657 		/* recover shadow used ring and available ring */
1658 		vq->shadow_used_idx -= num_descs;
1659 		vq->last_avail_idx -= num_descs;
1660 	}
1661 
1662 	/* keep used descriptors */
1663 	if (likely(vq->shadow_used_idx)) {
1664 		uint16_t to = async->desc_idx_split & (vq->size - 1);
1665 
1666 		store_dma_desc_info_split(vq->shadow_used_split,
1667 				async->descs_split, vq->size, 0, to,
1668 				vq->shadow_used_idx);
1669 
1670 		async->desc_idx_split += vq->shadow_used_idx;
1671 
1672 		async->pkts_idx += pkt_idx;
1673 		if (async->pkts_idx >= vq->size)
1674 			async->pkts_idx -= vq->size;
1675 
1676 		async->pkts_inflight_n += pkt_idx;
1677 		vq->shadow_used_idx = 0;
1678 	}
1679 
1680 	return pkt_idx;
1681 }
1682 
1683 
1684 static __rte_always_inline int
1685 vhost_enqueue_async_packed(struct virtio_net *dev,
1686 			    struct vhost_virtqueue *vq,
1687 			    struct rte_mbuf *pkt,
1688 			    struct buf_vector *buf_vec,
1689 			    uint16_t *nr_descs,
1690 			    uint16_t *nr_buffers)
1691 {
1692 	uint16_t nr_vec = 0;
1693 	uint16_t avail_idx = vq->last_avail_idx;
1694 	uint16_t max_tries, tries = 0;
1695 	uint16_t buf_id = 0;
1696 	uint32_t len = 0;
1697 	uint16_t desc_count = 0;
1698 	uint32_t size = pkt->pkt_len + sizeof(struct virtio_net_hdr_mrg_rxbuf);
1699 	uint32_t buffer_len[vq->size];
1700 	uint16_t buffer_buf_id[vq->size];
1701 	uint16_t buffer_desc_count[vq->size];
1702 
1703 	if (rxvq_is_mergeable(dev))
1704 		max_tries = vq->size - 1;
1705 	else
1706 		max_tries = 1;
1707 
1708 	while (size > 0) {
1709 		/*
1710 		 * if we tried all available ring items, and still
1711 		 * can't get enough buf, it means something abnormal
1712 		 * happened.
1713 		 */
1714 		if (unlikely(++tries > max_tries))
1715 			return -1;
1716 
1717 		if (unlikely(fill_vec_buf_packed(dev, vq,
1718 						avail_idx, &desc_count,
1719 						buf_vec, &nr_vec,
1720 						&buf_id, &len,
1721 						VHOST_ACCESS_RW) < 0))
1722 			return -1;
1723 
1724 		len = RTE_MIN(len, size);
1725 		size -= len;
1726 
1727 		buffer_len[*nr_buffers] = len;
1728 		buffer_buf_id[*nr_buffers] = buf_id;
1729 		buffer_desc_count[*nr_buffers] = desc_count;
1730 		*nr_buffers += 1;
1731 		*nr_descs += desc_count;
1732 		avail_idx += desc_count;
1733 		if (avail_idx >= vq->size)
1734 			avail_idx -= vq->size;
1735 	}
1736 
1737 	if (unlikely(mbuf_to_desc(dev, vq, pkt, buf_vec, nr_vec, *nr_buffers, true) < 0))
1738 		return -1;
1739 
1740 	vhost_shadow_enqueue_packed(vq, buffer_len, buffer_buf_id, buffer_desc_count, *nr_buffers);
1741 
1742 	return 0;
1743 }
1744 
1745 static __rte_always_inline int16_t
1746 virtio_dev_rx_async_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
1747 			    struct rte_mbuf *pkt, uint16_t *nr_descs, uint16_t *nr_buffers)
1748 {
1749 	struct buf_vector buf_vec[BUF_VECTOR_MAX];
1750 
1751 	if (unlikely(vhost_enqueue_async_packed(dev, vq, pkt, buf_vec,
1752 					nr_descs, nr_buffers) < 0)) {
1753 		VHOST_LOG_DATA(DEBUG, "(%s) failed to get enough desc from vring\n", dev->ifname);
1754 		return -1;
1755 	}
1756 
1757 	VHOST_LOG_DATA(DEBUG, "(%s) current index %d | end index %d\n",
1758 			dev->ifname, vq->last_avail_idx, vq->last_avail_idx + *nr_descs);
1759 
1760 	return 0;
1761 }
1762 
1763 static __rte_always_inline void
1764 dma_error_handler_packed(struct vhost_virtqueue *vq, uint16_t slot_idx,
1765 			uint32_t nr_err, uint32_t *pkt_idx)
1766 {
1767 	uint16_t descs_err = 0;
1768 	uint16_t buffers_err = 0;
1769 	struct async_inflight_info *pkts_info = vq->async->pkts_info;
1770 
1771 	*pkt_idx -= nr_err;
1772 	/* calculate the sum of buffers and descs of DMA-error packets. */
1773 	while (nr_err-- > 0) {
1774 		descs_err += pkts_info[slot_idx % vq->size].descs;
1775 		buffers_err += pkts_info[slot_idx % vq->size].nr_buffers;
1776 		slot_idx--;
1777 	}
1778 
1779 	if (vq->last_avail_idx >= descs_err) {
1780 		vq->last_avail_idx -= descs_err;
1781 	} else {
1782 		vq->last_avail_idx = vq->last_avail_idx + vq->size - descs_err;
1783 		vq->avail_wrap_counter ^= 1;
1784 	}
1785 
1786 	vq->shadow_used_idx -= buffers_err;
1787 }
1788 
1789 static __rte_noinline uint32_t
1790 virtio_dev_rx_async_submit_packed(struct virtio_net *dev, struct vhost_virtqueue *vq,
1791 		uint16_t queue_id, struct rte_mbuf **pkts, uint32_t count,
1792 		int16_t dma_id, uint16_t vchan_id)
1793 {
1794 	uint32_t pkt_idx = 0;
1795 	uint32_t remained = count;
1796 	uint16_t n_xfer;
1797 	uint16_t num_buffers;
1798 	uint16_t num_descs;
1799 
1800 	struct vhost_async *async = vq->async;
1801 	struct async_inflight_info *pkts_info = async->pkts_info;
1802 	uint32_t pkt_err = 0;
1803 	uint16_t slot_idx = 0;
1804 
1805 	do {
1806 		rte_prefetch0(&vq->desc_packed[vq->last_avail_idx]);
1807 
1808 		num_buffers = 0;
1809 		num_descs = 0;
1810 		if (unlikely(virtio_dev_rx_async_packed(dev, vq, pkts[pkt_idx],
1811 						&num_descs, &num_buffers) < 0))
1812 			break;
1813 
1814 		slot_idx = (async->pkts_idx + pkt_idx) % vq->size;
1815 
1816 		pkts_info[slot_idx].descs = num_descs;
1817 		pkts_info[slot_idx].nr_buffers = num_buffers;
1818 		pkts_info[slot_idx].mbuf = pkts[pkt_idx];
1819 
1820 		pkt_idx++;
1821 		remained--;
1822 		vq_inc_last_avail_packed(vq, num_descs);
1823 	} while (pkt_idx < count);
1824 
1825 	if (unlikely(pkt_idx == 0))
1826 		return 0;
1827 
1828 	n_xfer = vhost_async_dma_transfer(dev, vq, dma_id, vchan_id, async->pkts_idx,
1829 			async->iov_iter, pkt_idx);
1830 
1831 	async_iter_reset(async);
1832 
1833 	pkt_err = pkt_idx - n_xfer;
1834 	if (unlikely(pkt_err)) {
1835 		VHOST_LOG_DATA(DEBUG, "(%s) %s: failed to transfer %u packets for queue %u.\n",
1836 				dev->ifname, __func__, pkt_err, queue_id);
1837 		dma_error_handler_packed(vq, slot_idx, pkt_err, &pkt_idx);
1838 	}
1839 
1840 	if (likely(vq->shadow_used_idx)) {
1841 		/* keep used descriptors. */
1842 		store_dma_desc_info_packed(vq->shadow_used_packed, async->buffers_packed,
1843 					vq->size, 0, async->buffer_idx_packed,
1844 					vq->shadow_used_idx);
1845 
1846 		async->buffer_idx_packed += vq->shadow_used_idx;
1847 		if (async->buffer_idx_packed >= vq->size)
1848 			async->buffer_idx_packed -= vq->size;
1849 
1850 		async->pkts_idx += pkt_idx;
1851 		if (async->pkts_idx >= vq->size)
1852 			async->pkts_idx -= vq->size;
1853 
1854 		vq->shadow_used_idx = 0;
1855 		async->pkts_inflight_n += pkt_idx;
1856 	}
1857 
1858 	return pkt_idx;
1859 }
1860 
1861 static __rte_always_inline void
1862 write_back_completed_descs_split(struct vhost_virtqueue *vq, uint16_t n_descs)
1863 {
1864 	struct vhost_async *async = vq->async;
1865 	uint16_t nr_left = n_descs;
1866 	uint16_t nr_copy;
1867 	uint16_t to, from;
1868 
1869 	do {
1870 		from = async->last_desc_idx_split & (vq->size - 1);
1871 		nr_copy = nr_left + from <= vq->size ? nr_left : vq->size - from;
1872 		to = vq->last_used_idx & (vq->size - 1);
1873 
1874 		if (to + nr_copy <= vq->size) {
1875 			rte_memcpy(&vq->used->ring[to], &async->descs_split[from],
1876 					nr_copy * sizeof(struct vring_used_elem));
1877 		} else {
1878 			uint16_t size = vq->size - to;
1879 
1880 			rte_memcpy(&vq->used->ring[to], &async->descs_split[from],
1881 					size * sizeof(struct vring_used_elem));
1882 			rte_memcpy(&vq->used->ring[0], &async->descs_split[from + size],
1883 					(nr_copy - size) * sizeof(struct vring_used_elem));
1884 		}
1885 
1886 		async->last_desc_idx_split += nr_copy;
1887 		vq->last_used_idx += nr_copy;
1888 		nr_left -= nr_copy;
1889 	} while (nr_left > 0);
1890 }
1891 
1892 static __rte_always_inline void
1893 write_back_completed_descs_packed(struct vhost_virtqueue *vq,
1894 				uint16_t n_buffers)
1895 {
1896 	struct vhost_async *async = vq->async;
1897 	uint16_t from = async->last_buffer_idx_packed;
1898 	uint16_t used_idx = vq->last_used_idx;
1899 	uint16_t head_idx = vq->last_used_idx;
1900 	uint16_t head_flags = 0;
1901 	uint16_t i;
1902 
1903 	/* Split loop in two to save memory barriers */
1904 	for (i = 0; i < n_buffers; i++) {
1905 		vq->desc_packed[used_idx].id = async->buffers_packed[from].id;
1906 		vq->desc_packed[used_idx].len = async->buffers_packed[from].len;
1907 
1908 		used_idx += async->buffers_packed[from].count;
1909 		if (used_idx >= vq->size)
1910 			used_idx -= vq->size;
1911 
1912 		from++;
1913 		if (from >= vq->size)
1914 			from = 0;
1915 	}
1916 
1917 	/* The ordering for storing desc flags needs to be enforced. */
1918 	rte_atomic_thread_fence(__ATOMIC_RELEASE);
1919 
1920 	from = async->last_buffer_idx_packed;
1921 
1922 	for (i = 0; i < n_buffers; i++) {
1923 		uint16_t flags;
1924 
1925 		if (async->buffers_packed[from].len)
1926 			flags = VRING_DESC_F_WRITE;
1927 		else
1928 			flags = 0;
1929 
1930 		if (vq->used_wrap_counter) {
1931 			flags |= VRING_DESC_F_USED;
1932 			flags |= VRING_DESC_F_AVAIL;
1933 		} else {
1934 			flags &= ~VRING_DESC_F_USED;
1935 			flags &= ~VRING_DESC_F_AVAIL;
1936 		}
1937 
1938 		if (i > 0) {
1939 			vq->desc_packed[vq->last_used_idx].flags = flags;
1940 		} else {
1941 			head_idx = vq->last_used_idx;
1942 			head_flags = flags;
1943 		}
1944 
1945 		vq_inc_last_used_packed(vq, async->buffers_packed[from].count);
1946 
1947 		from++;
1948 		if (from == vq->size)
1949 			from = 0;
1950 	}
1951 
1952 	vq->desc_packed[head_idx].flags = head_flags;
1953 	async->last_buffer_idx_packed = from;
1954 }
1955 
1956 static __rte_always_inline uint16_t
1957 vhost_poll_enqueue_completed(struct virtio_net *dev, uint16_t queue_id,
1958 		struct rte_mbuf **pkts, uint16_t count, int16_t dma_id,
1959 		uint16_t vchan_id)
1960 {
1961 	struct vhost_virtqueue *vq = dev->virtqueue[queue_id];
1962 	struct vhost_async *async = vq->async;
1963 	struct async_inflight_info *pkts_info = async->pkts_info;
1964 	uint16_t nr_cpl_pkts = 0;
1965 	uint16_t n_descs = 0, n_buffers = 0;
1966 	uint16_t start_idx, from, i;
1967 
1968 	/* Check completed copies for the given DMA vChannel */
1969 	vhost_async_dma_check_completed(dev, dma_id, vchan_id, VHOST_DMA_MAX_COPY_COMPLETE);
1970 
1971 	start_idx = async_get_first_inflight_pkt_idx(vq);
1972 	/**
1973 	 * Calculate the number of copy completed packets.
1974 	 * Note that there may be completed packets even if
1975 	 * no copies are reported done by the given DMA vChannel,
1976 	 * as it's possible that a virtqueue uses multiple DMA
1977 	 * vChannels.
1978 	 */
1979 	from = start_idx;
1980 	while (vq->async->pkts_cmpl_flag[from] && count--) {
1981 		vq->async->pkts_cmpl_flag[from] = false;
1982 		from++;
1983 		if (from >= vq->size)
1984 			from -= vq->size;
1985 		nr_cpl_pkts++;
1986 	}
1987 
1988 	if (nr_cpl_pkts == 0)
1989 		return 0;
1990 
1991 	for (i = 0; i < nr_cpl_pkts; i++) {
1992 		from = (start_idx + i) % vq->size;
1993 		/* Only used with packed ring */
1994 		n_buffers += pkts_info[from].nr_buffers;
1995 		/* Only used with split ring */
1996 		n_descs += pkts_info[from].descs;
1997 		pkts[i] = pkts_info[from].mbuf;
1998 	}
1999 
2000 	async->pkts_inflight_n -= nr_cpl_pkts;
2001 
2002 	if (likely(vq->enabled && vq->access_ok)) {
2003 		if (vq_is_packed(dev)) {
2004 			write_back_completed_descs_packed(vq, n_buffers);
2005 			vhost_vring_call_packed(dev, vq);
2006 		} else {
2007 			write_back_completed_descs_split(vq, n_descs);
2008 			__atomic_add_fetch(&vq->used->idx, n_descs, __ATOMIC_RELEASE);
2009 			vhost_vring_call_split(dev, vq);
2010 		}
2011 	} else {
2012 		if (vq_is_packed(dev)) {
2013 			async->last_buffer_idx_packed += n_buffers;
2014 			if (async->last_buffer_idx_packed >= vq->size)
2015 				async->last_buffer_idx_packed -= vq->size;
2016 		} else {
2017 			async->last_desc_idx_split += n_descs;
2018 		}
2019 	}
2020 
2021 	return nr_cpl_pkts;
2022 }
2023 
2024 uint16_t
2025 rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
2026 		struct rte_mbuf **pkts, uint16_t count, int16_t dma_id,
2027 		uint16_t vchan_id)
2028 {
2029 	struct virtio_net *dev = get_device(vid);
2030 	struct vhost_virtqueue *vq;
2031 	uint16_t n_pkts_cpl = 0;
2032 
2033 	if (unlikely(!dev))
2034 		return 0;
2035 
2036 	VHOST_LOG_DATA(DEBUG, "(%s) %s\n", dev->ifname, __func__);
2037 	if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
2038 		VHOST_LOG_DATA(ERR, "(%s) %s: invalid virtqueue idx %d.\n",
2039 			dev->ifname, __func__, queue_id);
2040 		return 0;
2041 	}
2042 
2043 	if (unlikely(!dma_copy_track[dma_id].vchans ||
2044 				!dma_copy_track[dma_id].vchans[vchan_id].pkts_cmpl_flag_addr)) {
2045 		VHOST_LOG_DATA(ERR, "(%s) %s: invalid channel %d:%u.\n", dev->ifname, __func__,
2046 			       dma_id, vchan_id);
2047 		return 0;
2048 	}
2049 
2050 	vq = dev->virtqueue[queue_id];
2051 
2052 	if (!rte_spinlock_trylock(&vq->access_lock)) {
2053 		VHOST_LOG_DATA(DEBUG, "(%s) %s: virtqueue %u is busy.\n", dev->ifname, __func__,
2054 				queue_id);
2055 		return 0;
2056 	}
2057 
2058 	if (unlikely(!vq->async)) {
2059 		VHOST_LOG_DATA(ERR, "(%s) %s: async not registered for virtqueue %d.\n",
2060 				dev->ifname, __func__, queue_id);
2061 		goto out;
2062 	}
2063 
2064 	n_pkts_cpl = vhost_poll_enqueue_completed(dev, queue_id, pkts, count, dma_id, vchan_id);
2065 
2066 out:
2067 	rte_spinlock_unlock(&vq->access_lock);
2068 
2069 	return n_pkts_cpl;
2070 }
2071 
2072 uint16_t
2073 rte_vhost_clear_queue_thread_unsafe(int vid, uint16_t queue_id,
2074 		struct rte_mbuf **pkts, uint16_t count, int16_t dma_id,
2075 		uint16_t vchan_id)
2076 {
2077 	struct virtio_net *dev = get_device(vid);
2078 	struct vhost_virtqueue *vq;
2079 	uint16_t n_pkts_cpl = 0;
2080 
2081 	if (!dev)
2082 		return 0;
2083 
2084 	VHOST_LOG_DATA(DEBUG, "(%s) %s\n", dev->ifname, __func__);
2085 	if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
2086 		VHOST_LOG_DATA(ERR, "(%s) %s: invalid virtqueue idx %d.\n",
2087 			dev->ifname, __func__, queue_id);
2088 		return 0;
2089 	}
2090 
2091 	vq = dev->virtqueue[queue_id];
2092 
2093 	if (unlikely(!vq->async)) {
2094 		VHOST_LOG_DATA(ERR, "(%s) %s: async not registered for queue id %d.\n",
2095 			dev->ifname, __func__, queue_id);
2096 		return 0;
2097 	}
2098 
2099 	if (unlikely(!dma_copy_track[dma_id].vchans ||
2100 				!dma_copy_track[dma_id].vchans[vchan_id].pkts_cmpl_flag_addr)) {
2101 		VHOST_LOG_DATA(ERR, "(%s) %s: invalid channel %d:%u.\n", dev->ifname, __func__,
2102 				dma_id, vchan_id);
2103 		return 0;
2104 	}
2105 
2106 	n_pkts_cpl = vhost_poll_enqueue_completed(dev, queue_id, pkts, count, dma_id, vchan_id);
2107 
2108 	return n_pkts_cpl;
2109 }
2110 
2111 static __rte_always_inline uint32_t
2112 virtio_dev_rx_async_submit(struct virtio_net *dev, uint16_t queue_id,
2113 	struct rte_mbuf **pkts, uint32_t count, int16_t dma_id, uint16_t vchan_id)
2114 {
2115 	struct vhost_virtqueue *vq;
2116 	uint32_t nb_tx = 0;
2117 
2118 	VHOST_LOG_DATA(DEBUG, "(%s) %s\n", dev->ifname, __func__);
2119 	if (unlikely(!is_valid_virt_queue_idx(queue_id, 0, dev->nr_vring))) {
2120 		VHOST_LOG_DATA(ERR, "(%s) %s: invalid virtqueue idx %d.\n",
2121 			dev->ifname, __func__, queue_id);
2122 		return 0;
2123 	}
2124 
2125 	if (unlikely(!dma_copy_track[dma_id].vchans ||
2126 				!dma_copy_track[dma_id].vchans[vchan_id].pkts_cmpl_flag_addr)) {
2127 		VHOST_LOG_DATA(ERR, "(%s) %s: invalid channel %d:%u.\n", dev->ifname, __func__,
2128 			       dma_id, vchan_id);
2129 		return 0;
2130 	}
2131 
2132 	vq = dev->virtqueue[queue_id];
2133 
2134 	rte_spinlock_lock(&vq->access_lock);
2135 
2136 	if (unlikely(!vq->enabled || !vq->async))
2137 		goto out_access_unlock;
2138 
2139 	if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
2140 		vhost_user_iotlb_rd_lock(vq);
2141 
2142 	if (unlikely(!vq->access_ok))
2143 		if (unlikely(vring_translate(dev, vq) < 0))
2144 			goto out;
2145 
2146 	count = RTE_MIN((uint32_t)MAX_PKT_BURST, count);
2147 	if (count == 0)
2148 		goto out;
2149 
2150 	if (vq_is_packed(dev))
2151 		nb_tx = virtio_dev_rx_async_submit_packed(dev, vq, queue_id,
2152 				pkts, count, dma_id, vchan_id);
2153 	else
2154 		nb_tx = virtio_dev_rx_async_submit_split(dev, vq, queue_id,
2155 				pkts, count, dma_id, vchan_id);
2156 
2157 out:
2158 	if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
2159 		vhost_user_iotlb_rd_unlock(vq);
2160 
2161 out_access_unlock:
2162 	rte_spinlock_unlock(&vq->access_lock);
2163 
2164 	return nb_tx;
2165 }
2166 
2167 uint16_t
2168 rte_vhost_submit_enqueue_burst(int vid, uint16_t queue_id,
2169 		struct rte_mbuf **pkts, uint16_t count, int16_t dma_id,
2170 		uint16_t vchan_id)
2171 {
2172 	struct virtio_net *dev = get_device(vid);
2173 
2174 	if (!dev)
2175 		return 0;
2176 
2177 	if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
2178 		VHOST_LOG_DATA(ERR, "(%s) %s: built-in vhost net backend is disabled.\n",
2179 			dev->ifname, __func__);
2180 		return 0;
2181 	}
2182 
2183 	return virtio_dev_rx_async_submit(dev, queue_id, pkts, count, dma_id, vchan_id);
2184 }
2185 
2186 static inline bool
2187 virtio_net_with_host_offload(struct virtio_net *dev)
2188 {
2189 	if (dev->features &
2190 			((1ULL << VIRTIO_NET_F_CSUM) |
2191 			 (1ULL << VIRTIO_NET_F_HOST_ECN) |
2192 			 (1ULL << VIRTIO_NET_F_HOST_TSO4) |
2193 			 (1ULL << VIRTIO_NET_F_HOST_TSO6) |
2194 			 (1ULL << VIRTIO_NET_F_HOST_UFO)))
2195 		return true;
2196 
2197 	return false;
2198 }
2199 
2200 static int
2201 parse_headers(struct rte_mbuf *m, uint8_t *l4_proto)
2202 {
2203 	struct rte_ipv4_hdr *ipv4_hdr;
2204 	struct rte_ipv6_hdr *ipv6_hdr;
2205 	struct rte_ether_hdr *eth_hdr;
2206 	uint16_t ethertype;
2207 	uint16_t data_len = rte_pktmbuf_data_len(m);
2208 
2209 	if (data_len < sizeof(struct rte_ether_hdr))
2210 		return -EINVAL;
2211 
2212 	eth_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
2213 
2214 	m->l2_len = sizeof(struct rte_ether_hdr);
2215 	ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);
2216 
2217 	if (ethertype == RTE_ETHER_TYPE_VLAN) {
2218 		if (data_len < sizeof(struct rte_ether_hdr) +
2219 				sizeof(struct rte_vlan_hdr))
2220 			goto error;
2221 
2222 		struct rte_vlan_hdr *vlan_hdr =
2223 			(struct rte_vlan_hdr *)(eth_hdr + 1);
2224 
2225 		m->l2_len += sizeof(struct rte_vlan_hdr);
2226 		ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
2227 	}
2228 
2229 	switch (ethertype) {
2230 	case RTE_ETHER_TYPE_IPV4:
2231 		if (data_len < m->l2_len + sizeof(struct rte_ipv4_hdr))
2232 			goto error;
2233 		ipv4_hdr = rte_pktmbuf_mtod_offset(m, struct rte_ipv4_hdr *,
2234 				m->l2_len);
2235 		m->l3_len = rte_ipv4_hdr_len(ipv4_hdr);
2236 		if (data_len < m->l2_len + m->l3_len)
2237 			goto error;
2238 		m->ol_flags |= RTE_MBUF_F_TX_IPV4;
2239 		*l4_proto = ipv4_hdr->next_proto_id;
2240 		break;
2241 	case RTE_ETHER_TYPE_IPV6:
2242 		if (data_len < m->l2_len + sizeof(struct rte_ipv6_hdr))
2243 			goto error;
2244 		ipv6_hdr = rte_pktmbuf_mtod_offset(m, struct rte_ipv6_hdr *,
2245 				m->l2_len);
2246 		m->l3_len = sizeof(struct rte_ipv6_hdr);
2247 		m->ol_flags |= RTE_MBUF_F_TX_IPV6;
2248 		*l4_proto = ipv6_hdr->proto;
2249 		break;
2250 	default:
2251 		/* a valid L3 header is needed for further L4 parsing */
2252 		goto error;
2253 	}
2254 
2255 	/* both CSUM and GSO need a valid L4 header */
2256 	switch (*l4_proto) {
2257 	case IPPROTO_TCP:
2258 		if (data_len < m->l2_len + m->l3_len +
2259 				sizeof(struct rte_tcp_hdr))
2260 			goto error;
2261 		break;
2262 	case IPPROTO_UDP:
2263 		if (data_len < m->l2_len + m->l3_len +
2264 				sizeof(struct rte_udp_hdr))
2265 			goto error;
2266 		break;
2267 	case IPPROTO_SCTP:
2268 		if (data_len < m->l2_len + m->l3_len +
2269 				sizeof(struct rte_sctp_hdr))
2270 			goto error;
2271 		break;
2272 	default:
2273 		goto error;
2274 	}
2275 
2276 	return 0;
2277 
2278 error:
2279 	m->l2_len = 0;
2280 	m->l3_len = 0;
2281 	m->ol_flags = 0;
2282 	return -EINVAL;
2283 }
2284 
2285 static __rte_always_inline void
2286 vhost_dequeue_offload_legacy(struct virtio_net *dev, struct virtio_net_hdr *hdr,
2287 		struct rte_mbuf *m)
2288 {
2289 	uint8_t l4_proto = 0;
2290 	struct rte_tcp_hdr *tcp_hdr = NULL;
2291 	uint16_t tcp_len;
2292 	uint16_t data_len = rte_pktmbuf_data_len(m);
2293 
2294 	if (parse_headers(m, &l4_proto) < 0)
2295 		return;
2296 
2297 	if (hdr->flags == VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2298 		if (hdr->csum_start == (m->l2_len + m->l3_len)) {
2299 			switch (hdr->csum_offset) {
2300 			case (offsetof(struct rte_tcp_hdr, cksum)):
2301 				if (l4_proto != IPPROTO_TCP)
2302 					goto error;
2303 				m->ol_flags |= RTE_MBUF_F_TX_TCP_CKSUM;
2304 				break;
2305 			case (offsetof(struct rte_udp_hdr, dgram_cksum)):
2306 				if (l4_proto != IPPROTO_UDP)
2307 					goto error;
2308 				m->ol_flags |= RTE_MBUF_F_TX_UDP_CKSUM;
2309 				break;
2310 			case (offsetof(struct rte_sctp_hdr, cksum)):
2311 				if (l4_proto != IPPROTO_SCTP)
2312 					goto error;
2313 				m->ol_flags |= RTE_MBUF_F_TX_SCTP_CKSUM;
2314 				break;
2315 			default:
2316 				goto error;
2317 			}
2318 		} else {
2319 			goto error;
2320 		}
2321 	}
2322 
2323 	if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2324 		switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2325 		case VIRTIO_NET_HDR_GSO_TCPV4:
2326 		case VIRTIO_NET_HDR_GSO_TCPV6:
2327 			if (l4_proto != IPPROTO_TCP)
2328 				goto error;
2329 			tcp_hdr = rte_pktmbuf_mtod_offset(m,
2330 					struct rte_tcp_hdr *,
2331 					m->l2_len + m->l3_len);
2332 			tcp_len = (tcp_hdr->data_off & 0xf0) >> 2;
2333 			if (data_len < m->l2_len + m->l3_len + tcp_len)
2334 				goto error;
2335 			m->ol_flags |= RTE_MBUF_F_TX_TCP_SEG;
2336 			m->tso_segsz = hdr->gso_size;
2337 			m->l4_len = tcp_len;
2338 			break;
2339 		case VIRTIO_NET_HDR_GSO_UDP:
2340 			if (l4_proto != IPPROTO_UDP)
2341 				goto error;
2342 			m->ol_flags |= RTE_MBUF_F_TX_UDP_SEG;
2343 			m->tso_segsz = hdr->gso_size;
2344 			m->l4_len = sizeof(struct rte_udp_hdr);
2345 			break;
2346 		default:
2347 			VHOST_LOG_DATA(WARNING, "(%s) unsupported gso type %u.\n",
2348 					dev->ifname, hdr->gso_type);
2349 			goto error;
2350 		}
2351 	}
2352 	return;
2353 
2354 error:
2355 	m->l2_len = 0;
2356 	m->l3_len = 0;
2357 	m->ol_flags = 0;
2358 }
2359 
2360 static __rte_always_inline void
2361 vhost_dequeue_offload(struct virtio_net *dev, struct virtio_net_hdr *hdr,
2362 		struct rte_mbuf *m, bool legacy_ol_flags)
2363 {
2364 	struct rte_net_hdr_lens hdr_lens;
2365 	int l4_supported = 0;
2366 	uint32_t ptype;
2367 
2368 	if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
2369 		return;
2370 
2371 	if (legacy_ol_flags) {
2372 		vhost_dequeue_offload_legacy(dev, hdr, m);
2373 		return;
2374 	}
2375 
2376 	m->ol_flags |= RTE_MBUF_F_RX_IP_CKSUM_UNKNOWN;
2377 
2378 	ptype = rte_net_get_ptype(m, &hdr_lens, RTE_PTYPE_ALL_MASK);
2379 	m->packet_type = ptype;
2380 	if ((ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_TCP ||
2381 	    (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_UDP ||
2382 	    (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_SCTP)
2383 		l4_supported = 1;
2384 
2385 	/* According to Virtio 1.1 spec, the device only needs to look at
2386 	 * VIRTIO_NET_HDR_F_NEEDS_CSUM in the packet transmission path.
2387 	 * This differs from the processing incoming packets path where the
2388 	 * driver could rely on VIRTIO_NET_HDR_F_DATA_VALID flag set by the
2389 	 * device.
2390 	 *
2391 	 * 5.1.6.2.1 Driver Requirements: Packet Transmission
2392 	 * The driver MUST NOT set the VIRTIO_NET_HDR_F_DATA_VALID and
2393 	 * VIRTIO_NET_HDR_F_RSC_INFO bits in flags.
2394 	 *
2395 	 * 5.1.6.2.2 Device Requirements: Packet Transmission
2396 	 * The device MUST ignore flag bits that it does not recognize.
2397 	 */
2398 	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2399 		uint32_t hdrlen;
2400 
2401 		hdrlen = hdr_lens.l2_len + hdr_lens.l3_len + hdr_lens.l4_len;
2402 		if (hdr->csum_start <= hdrlen && l4_supported != 0) {
2403 			m->ol_flags |= RTE_MBUF_F_RX_L4_CKSUM_NONE;
2404 		} else {
2405 			/* Unknown proto or tunnel, do sw cksum. We can assume
2406 			 * the cksum field is in the first segment since the
2407 			 * buffers we provided to the host are large enough.
2408 			 * In case of SCTP, this will be wrong since it's a CRC
2409 			 * but there's nothing we can do.
2410 			 */
2411 			uint16_t csum = 0, off;
2412 
2413 			if (rte_raw_cksum_mbuf(m, hdr->csum_start,
2414 					rte_pktmbuf_pkt_len(m) - hdr->csum_start, &csum) < 0)
2415 				return;
2416 			if (likely(csum != 0xffff))
2417 				csum = ~csum;
2418 			off = hdr->csum_offset + hdr->csum_start;
2419 			if (rte_pktmbuf_data_len(m) >= off + 1)
2420 				*rte_pktmbuf_mtod_offset(m, uint16_t *, off) = csum;
2421 		}
2422 	}
2423 
2424 	if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2425 		if (hdr->gso_size == 0)
2426 			return;
2427 
2428 		switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2429 		case VIRTIO_NET_HDR_GSO_TCPV4:
2430 		case VIRTIO_NET_HDR_GSO_TCPV6:
2431 			if ((ptype & RTE_PTYPE_L4_MASK) != RTE_PTYPE_L4_TCP)
2432 				break;
2433 			m->ol_flags |= RTE_MBUF_F_RX_LRO | RTE_MBUF_F_RX_L4_CKSUM_NONE;
2434 			m->tso_segsz = hdr->gso_size;
2435 			break;
2436 		case VIRTIO_NET_HDR_GSO_UDP:
2437 			if ((ptype & RTE_PTYPE_L4_MASK) != RTE_PTYPE_L4_UDP)
2438 				break;
2439 			m->ol_flags |= RTE_MBUF_F_RX_LRO | RTE_MBUF_F_RX_L4_CKSUM_NONE;
2440 			m->tso_segsz = hdr->gso_size;
2441 			break;
2442 		default:
2443 			break;
2444 		}
2445 	}
2446 }
2447 
2448 static __rte_noinline void
2449 copy_vnet_hdr_from_desc(struct virtio_net_hdr *hdr,
2450 		struct buf_vector *buf_vec)
2451 {
2452 	uint64_t len;
2453 	uint64_t remain = sizeof(struct virtio_net_hdr);
2454 	uint64_t src;
2455 	uint64_t dst = (uint64_t)(uintptr_t)hdr;
2456 
2457 	while (remain) {
2458 		len = RTE_MIN(remain, buf_vec->buf_len);
2459 		src = buf_vec->buf_addr;
2460 		rte_memcpy((void *)(uintptr_t)dst,
2461 				(void *)(uintptr_t)src, len);
2462 
2463 		remain -= len;
2464 		dst += len;
2465 		buf_vec++;
2466 	}
2467 }
2468 
2469 static __rte_always_inline int
2470 copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
2471 		  struct buf_vector *buf_vec, uint16_t nr_vec,
2472 		  struct rte_mbuf *m, struct rte_mempool *mbuf_pool,
2473 		  bool legacy_ol_flags)
2474 {
2475 	uint32_t buf_avail, buf_offset;
2476 	uint64_t buf_addr, buf_len;
2477 	uint32_t mbuf_avail, mbuf_offset;
2478 	uint32_t cpy_len;
2479 	struct rte_mbuf *cur = m, *prev = m;
2480 	struct virtio_net_hdr tmp_hdr;
2481 	struct virtio_net_hdr *hdr = NULL;
2482 	/* A counter to avoid desc dead loop chain */
2483 	uint16_t vec_idx = 0;
2484 	struct batch_copy_elem *batch_copy = vq->batch_copy_elems;
2485 	int error = 0;
2486 
2487 	buf_addr = buf_vec[vec_idx].buf_addr;
2488 	buf_len = buf_vec[vec_idx].buf_len;
2489 
2490 	if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1)) {
2491 		error = -1;
2492 		goto out;
2493 	}
2494 
2495 	if (virtio_net_with_host_offload(dev)) {
2496 		if (unlikely(buf_len < sizeof(struct virtio_net_hdr))) {
2497 			/*
2498 			 * No luck, the virtio-net header doesn't fit
2499 			 * in a contiguous virtual area.
2500 			 */
2501 			copy_vnet_hdr_from_desc(&tmp_hdr, buf_vec);
2502 			hdr = &tmp_hdr;
2503 		} else {
2504 			hdr = (struct virtio_net_hdr *)((uintptr_t)buf_addr);
2505 		}
2506 	}
2507 
2508 	/*
2509 	 * A virtio driver normally uses at least 2 desc buffers
2510 	 * for Tx: the first for storing the header, and others
2511 	 * for storing the data.
2512 	 */
2513 	if (unlikely(buf_len < dev->vhost_hlen)) {
2514 		buf_offset = dev->vhost_hlen - buf_len;
2515 		vec_idx++;
2516 		buf_addr = buf_vec[vec_idx].buf_addr;
2517 		buf_len = buf_vec[vec_idx].buf_len;
2518 		buf_avail  = buf_len - buf_offset;
2519 	} else if (buf_len == dev->vhost_hlen) {
2520 		if (unlikely(++vec_idx >= nr_vec))
2521 			goto out;
2522 		buf_addr = buf_vec[vec_idx].buf_addr;
2523 		buf_len = buf_vec[vec_idx].buf_len;
2524 
2525 		buf_offset = 0;
2526 		buf_avail = buf_len;
2527 	} else {
2528 		buf_offset = dev->vhost_hlen;
2529 		buf_avail = buf_vec[vec_idx].buf_len - dev->vhost_hlen;
2530 	}
2531 
2532 	PRINT_PACKET(dev,
2533 			(uintptr_t)(buf_addr + buf_offset),
2534 			(uint32_t)buf_avail, 0);
2535 
2536 	mbuf_offset = 0;
2537 	mbuf_avail  = m->buf_len - RTE_PKTMBUF_HEADROOM;
2538 	while (1) {
2539 		cpy_len = RTE_MIN(buf_avail, mbuf_avail);
2540 
2541 		if (likely(cpy_len > MAX_BATCH_LEN ||
2542 					vq->batch_copy_nb_elems >= vq->size ||
2543 					(hdr && cur == m))) {
2544 			rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *,
2545 						mbuf_offset),
2546 					(void *)((uintptr_t)(buf_addr +
2547 							buf_offset)), cpy_len);
2548 		} else {
2549 			batch_copy[vq->batch_copy_nb_elems].dst =
2550 				rte_pktmbuf_mtod_offset(cur, void *,
2551 						mbuf_offset);
2552 			batch_copy[vq->batch_copy_nb_elems].src =
2553 				(void *)((uintptr_t)(buf_addr + buf_offset));
2554 			batch_copy[vq->batch_copy_nb_elems].len = cpy_len;
2555 			vq->batch_copy_nb_elems++;
2556 		}
2557 
2558 		mbuf_avail  -= cpy_len;
2559 		mbuf_offset += cpy_len;
2560 		buf_avail -= cpy_len;
2561 		buf_offset += cpy_len;
2562 
2563 		/* This buf reaches to its end, get the next one */
2564 		if (buf_avail == 0) {
2565 			if (++vec_idx >= nr_vec)
2566 				break;
2567 
2568 			buf_addr = buf_vec[vec_idx].buf_addr;
2569 			buf_len = buf_vec[vec_idx].buf_len;
2570 
2571 			buf_offset = 0;
2572 			buf_avail  = buf_len;
2573 
2574 			PRINT_PACKET(dev, (uintptr_t)buf_addr,
2575 					(uint32_t)buf_avail, 0);
2576 		}
2577 
2578 		/*
2579 		 * This mbuf reaches to its end, get a new one
2580 		 * to hold more data.
2581 		 */
2582 		if (mbuf_avail == 0) {
2583 			cur = rte_pktmbuf_alloc(mbuf_pool);
2584 			if (unlikely(cur == NULL)) {
2585 				VHOST_LOG_DATA(ERR, "(%s) failed to allocate memory for mbuf.\n",
2586 						dev->ifname);
2587 				error = -1;
2588 				goto out;
2589 			}
2590 
2591 			prev->next = cur;
2592 			prev->data_len = mbuf_offset;
2593 			m->nb_segs += 1;
2594 			m->pkt_len += mbuf_offset;
2595 			prev = cur;
2596 
2597 			mbuf_offset = 0;
2598 			mbuf_avail  = cur->buf_len - RTE_PKTMBUF_HEADROOM;
2599 		}
2600 	}
2601 
2602 	prev->data_len = mbuf_offset;
2603 	m->pkt_len    += mbuf_offset;
2604 
2605 	if (hdr)
2606 		vhost_dequeue_offload(dev, hdr, m, legacy_ol_flags);
2607 
2608 out:
2609 
2610 	return error;
2611 }
2612 
2613 static void
2614 virtio_dev_extbuf_free(void *addr __rte_unused, void *opaque)
2615 {
2616 	rte_free(opaque);
2617 }
2618 
2619 static int
2620 virtio_dev_extbuf_alloc(struct virtio_net *dev, struct rte_mbuf *pkt, uint32_t size)
2621 {
2622 	struct rte_mbuf_ext_shared_info *shinfo = NULL;
2623 	uint32_t total_len = RTE_PKTMBUF_HEADROOM + size;
2624 	uint16_t buf_len;
2625 	rte_iova_t iova;
2626 	void *buf;
2627 
2628 	total_len += sizeof(*shinfo) + sizeof(uintptr_t);
2629 	total_len = RTE_ALIGN_CEIL(total_len, sizeof(uintptr_t));
2630 
2631 	if (unlikely(total_len > UINT16_MAX))
2632 		return -ENOSPC;
2633 
2634 	buf_len = total_len;
2635 	buf = rte_malloc(NULL, buf_len, RTE_CACHE_LINE_SIZE);
2636 	if (unlikely(buf == NULL))
2637 		return -ENOMEM;
2638 
2639 	/* Initialize shinfo */
2640 	shinfo = rte_pktmbuf_ext_shinfo_init_helper(buf, &buf_len,
2641 						virtio_dev_extbuf_free, buf);
2642 	if (unlikely(shinfo == NULL)) {
2643 		rte_free(buf);
2644 		VHOST_LOG_DATA(ERR, "(%s) failed to init shinfo\n", dev->ifname);
2645 		return -1;
2646 	}
2647 
2648 	iova = rte_malloc_virt2iova(buf);
2649 	rte_pktmbuf_attach_extbuf(pkt, buf, iova, buf_len, shinfo);
2650 	rte_pktmbuf_reset_headroom(pkt);
2651 
2652 	return 0;
2653 }
2654 
2655 /*
2656  * Prepare a host supported pktmbuf.
2657  */
2658 static __rte_always_inline int
2659 virtio_dev_pktmbuf_prep(struct virtio_net *dev, struct rte_mbuf *pkt,
2660 			 uint32_t data_len)
2661 {
2662 	if (rte_pktmbuf_tailroom(pkt) >= data_len)
2663 		return 0;
2664 
2665 	/* attach an external buffer if supported */
2666 	if (dev->extbuf && !virtio_dev_extbuf_alloc(dev, pkt, data_len))
2667 		return 0;
2668 
2669 	/* check if chained buffers are allowed */
2670 	if (!dev->linearbuf)
2671 		return 0;
2672 
2673 	return -1;
2674 }
2675 
2676 __rte_always_inline
2677 static uint16_t
2678 virtio_dev_tx_split(struct virtio_net *dev, struct vhost_virtqueue *vq,
2679 	struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count,
2680 	bool legacy_ol_flags)
2681 {
2682 	uint16_t i;
2683 	uint16_t free_entries;
2684 	uint16_t dropped = 0;
2685 	static bool allocerr_warned;
2686 
2687 	/*
2688 	 * The ordering between avail index and
2689 	 * desc reads needs to be enforced.
2690 	 */
2691 	free_entries = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE) -
2692 			vq->last_avail_idx;
2693 	if (free_entries == 0)
2694 		return 0;
2695 
2696 	rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
2697 
2698 	VHOST_LOG_DATA(DEBUG, "(%s) %s\n", dev->ifname, __func__);
2699 
2700 	count = RTE_MIN(count, MAX_PKT_BURST);
2701 	count = RTE_MIN(count, free_entries);
2702 	VHOST_LOG_DATA(DEBUG, "(%s) about to dequeue %u buffers\n",
2703 			dev->ifname, count);
2704 
2705 	if (rte_pktmbuf_alloc_bulk(mbuf_pool, pkts, count))
2706 		return 0;
2707 
2708 	for (i = 0; i < count; i++) {
2709 		struct buf_vector buf_vec[BUF_VECTOR_MAX];
2710 		uint16_t head_idx;
2711 		uint32_t buf_len;
2712 		uint16_t nr_vec = 0;
2713 		int err;
2714 
2715 		if (unlikely(fill_vec_buf_split(dev, vq,
2716 						vq->last_avail_idx + i,
2717 						&nr_vec, buf_vec,
2718 						&head_idx, &buf_len,
2719 						VHOST_ACCESS_RO) < 0))
2720 			break;
2721 
2722 		update_shadow_used_ring_split(vq, head_idx, 0);
2723 
2724 		err = virtio_dev_pktmbuf_prep(dev, pkts[i], buf_len);
2725 		if (unlikely(err)) {
2726 			/*
2727 			 * mbuf allocation fails for jumbo packets when external
2728 			 * buffer allocation is not allowed and linear buffer
2729 			 * is required. Drop this packet.
2730 			 */
2731 			if (!allocerr_warned) {
2732 				VHOST_LOG_DATA(ERR, "(%s) failed mbuf alloc of size %d from %s.\n",
2733 					dev->ifname, buf_len, mbuf_pool->name);
2734 				allocerr_warned = true;
2735 			}
2736 			dropped += 1;
2737 			i++;
2738 			break;
2739 		}
2740 
2741 		err = copy_desc_to_mbuf(dev, vq, buf_vec, nr_vec, pkts[i],
2742 				mbuf_pool, legacy_ol_flags);
2743 		if (unlikely(err)) {
2744 			if (!allocerr_warned) {
2745 				VHOST_LOG_DATA(ERR, "(%s) failed to copy desc to mbuf.\n",
2746 					dev->ifname);
2747 				allocerr_warned = true;
2748 			}
2749 			dropped += 1;
2750 			i++;
2751 			break;
2752 		}
2753 	}
2754 
2755 	if (dropped)
2756 		rte_pktmbuf_free_bulk(&pkts[i - 1], count - i + 1);
2757 
2758 	vq->last_avail_idx += i;
2759 
2760 	do_data_copy_dequeue(vq);
2761 	if (unlikely(i < count))
2762 		vq->shadow_used_idx = i;
2763 	if (likely(vq->shadow_used_idx)) {
2764 		flush_shadow_used_ring_split(dev, vq);
2765 		vhost_vring_call_split(dev, vq);
2766 	}
2767 
2768 	return (i - dropped);
2769 }
2770 
2771 __rte_noinline
2772 static uint16_t
2773 virtio_dev_tx_split_legacy(struct virtio_net *dev,
2774 	struct vhost_virtqueue *vq, struct rte_mempool *mbuf_pool,
2775 	struct rte_mbuf **pkts, uint16_t count)
2776 {
2777 	return virtio_dev_tx_split(dev, vq, mbuf_pool, pkts, count, true);
2778 }
2779 
2780 __rte_noinline
2781 static uint16_t
2782 virtio_dev_tx_split_compliant(struct virtio_net *dev,
2783 	struct vhost_virtqueue *vq, struct rte_mempool *mbuf_pool,
2784 	struct rte_mbuf **pkts, uint16_t count)
2785 {
2786 	return virtio_dev_tx_split(dev, vq, mbuf_pool, pkts, count, false);
2787 }
2788 
2789 static __rte_always_inline int
2790 vhost_reserve_avail_batch_packed(struct virtio_net *dev,
2791 				 struct vhost_virtqueue *vq,
2792 				 struct rte_mbuf **pkts,
2793 				 uint16_t avail_idx,
2794 				 uintptr_t *desc_addrs,
2795 				 uint16_t *ids)
2796 {
2797 	bool wrap = vq->avail_wrap_counter;
2798 	struct vring_packed_desc *descs = vq->desc_packed;
2799 	uint64_t lens[PACKED_BATCH_SIZE];
2800 	uint64_t buf_lens[PACKED_BATCH_SIZE];
2801 	uint32_t buf_offset = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2802 	uint16_t flags, i;
2803 
2804 	if (unlikely(avail_idx & PACKED_BATCH_MASK))
2805 		return -1;
2806 	if (unlikely((avail_idx + PACKED_BATCH_SIZE) > vq->size))
2807 		return -1;
2808 
2809 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
2810 		flags = descs[avail_idx + i].flags;
2811 		if (unlikely((wrap != !!(flags & VRING_DESC_F_AVAIL)) ||
2812 			     (wrap == !!(flags & VRING_DESC_F_USED))  ||
2813 			     (flags & PACKED_DESC_SINGLE_DEQUEUE_FLAG)))
2814 			return -1;
2815 	}
2816 
2817 	rte_atomic_thread_fence(__ATOMIC_ACQUIRE);
2818 
2819 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
2820 		lens[i] = descs[avail_idx + i].len;
2821 
2822 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
2823 		desc_addrs[i] = vhost_iova_to_vva(dev, vq,
2824 						  descs[avail_idx + i].addr,
2825 						  &lens[i], VHOST_ACCESS_RW);
2826 	}
2827 
2828 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
2829 		if (unlikely(!desc_addrs[i]))
2830 			return -1;
2831 		if (unlikely((lens[i] != descs[avail_idx + i].len)))
2832 			return -1;
2833 	}
2834 
2835 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
2836 		if (virtio_dev_pktmbuf_prep(dev, pkts[i], lens[i]))
2837 			goto err;
2838 	}
2839 
2840 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
2841 		buf_lens[i] = pkts[i]->buf_len - pkts[i]->data_off;
2842 
2843 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
2844 		if (unlikely(buf_lens[i] < (lens[i] - buf_offset)))
2845 			goto err;
2846 	}
2847 
2848 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
2849 		pkts[i]->pkt_len = lens[i] - buf_offset;
2850 		pkts[i]->data_len = pkts[i]->pkt_len;
2851 		ids[i] = descs[avail_idx + i].id;
2852 	}
2853 
2854 	return 0;
2855 
2856 err:
2857 	return -1;
2858 }
2859 
2860 static __rte_always_inline int
2861 virtio_dev_tx_batch_packed(struct virtio_net *dev,
2862 			   struct vhost_virtqueue *vq,
2863 			   struct rte_mbuf **pkts,
2864 			   bool legacy_ol_flags)
2865 {
2866 	uint16_t avail_idx = vq->last_avail_idx;
2867 	uint32_t buf_offset = sizeof(struct virtio_net_hdr_mrg_rxbuf);
2868 	struct virtio_net_hdr *hdr;
2869 	uintptr_t desc_addrs[PACKED_BATCH_SIZE];
2870 	uint16_t ids[PACKED_BATCH_SIZE];
2871 	uint16_t i;
2872 
2873 	if (vhost_reserve_avail_batch_packed(dev, vq, pkts, avail_idx,
2874 					     desc_addrs, ids))
2875 		return -1;
2876 
2877 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
2878 		rte_prefetch0((void *)(uintptr_t)desc_addrs[i]);
2879 
2880 	vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE)
2881 		rte_memcpy(rte_pktmbuf_mtod_offset(pkts[i], void *, 0),
2882 			   (void *)(uintptr_t)(desc_addrs[i] + buf_offset),
2883 			   pkts[i]->pkt_len);
2884 
2885 	if (virtio_net_with_host_offload(dev)) {
2886 		vhost_for_each_try_unroll(i, 0, PACKED_BATCH_SIZE) {
2887 			hdr = (struct virtio_net_hdr *)(desc_addrs[i]);
2888 			vhost_dequeue_offload(dev, hdr, pkts[i], legacy_ol_flags);
2889 		}
2890 	}
2891 
2892 	if (virtio_net_is_inorder(dev))
2893 		vhost_shadow_dequeue_batch_packed_inorder(vq,
2894 			ids[PACKED_BATCH_SIZE - 1]);
2895 	else
2896 		vhost_shadow_dequeue_batch_packed(dev, vq, ids);
2897 
2898 	vq_inc_last_avail_packed(vq, PACKED_BATCH_SIZE);
2899 
2900 	return 0;
2901 }
2902 
2903 static __rte_always_inline int
2904 vhost_dequeue_single_packed(struct virtio_net *dev,
2905 			    struct vhost_virtqueue *vq,
2906 			    struct rte_mempool *mbuf_pool,
2907 			    struct rte_mbuf *pkts,
2908 			    uint16_t *buf_id,
2909 			    uint16_t *desc_count,
2910 			    bool legacy_ol_flags)
2911 {
2912 	struct buf_vector buf_vec[BUF_VECTOR_MAX];
2913 	uint32_t buf_len;
2914 	uint16_t nr_vec = 0;
2915 	int err;
2916 	static bool allocerr_warned;
2917 
2918 	if (unlikely(fill_vec_buf_packed(dev, vq,
2919 					 vq->last_avail_idx, desc_count,
2920 					 buf_vec, &nr_vec,
2921 					 buf_id, &buf_len,
2922 					 VHOST_ACCESS_RO) < 0))
2923 		return -1;
2924 
2925 	if (unlikely(virtio_dev_pktmbuf_prep(dev, pkts, buf_len))) {
2926 		if (!allocerr_warned) {
2927 			VHOST_LOG_DATA(ERR, "(%s) failed mbuf alloc of size %d from %s.\n",
2928 				dev->ifname, buf_len, mbuf_pool->name);
2929 			allocerr_warned = true;
2930 		}
2931 		return -1;
2932 	}
2933 
2934 	err = copy_desc_to_mbuf(dev, vq, buf_vec, nr_vec, pkts,
2935 				mbuf_pool, legacy_ol_flags);
2936 	if (unlikely(err)) {
2937 		if (!allocerr_warned) {
2938 			VHOST_LOG_DATA(ERR, "(%s) failed to copy desc to mbuf.\n",
2939 				dev->ifname);
2940 			allocerr_warned = true;
2941 		}
2942 		return -1;
2943 	}
2944 
2945 	return 0;
2946 }
2947 
2948 static __rte_always_inline int
2949 virtio_dev_tx_single_packed(struct virtio_net *dev,
2950 			    struct vhost_virtqueue *vq,
2951 			    struct rte_mempool *mbuf_pool,
2952 			    struct rte_mbuf *pkts,
2953 			    bool legacy_ol_flags)
2954 {
2955 
2956 	uint16_t buf_id, desc_count = 0;
2957 	int ret;
2958 
2959 	ret = vhost_dequeue_single_packed(dev, vq, mbuf_pool, pkts, &buf_id,
2960 					&desc_count, legacy_ol_flags);
2961 
2962 	if (likely(desc_count > 0)) {
2963 		if (virtio_net_is_inorder(dev))
2964 			vhost_shadow_dequeue_single_packed_inorder(vq, buf_id,
2965 								   desc_count);
2966 		else
2967 			vhost_shadow_dequeue_single_packed(vq, buf_id,
2968 					desc_count);
2969 
2970 		vq_inc_last_avail_packed(vq, desc_count);
2971 	}
2972 
2973 	return ret;
2974 }
2975 
2976 __rte_always_inline
2977 static uint16_t
2978 virtio_dev_tx_packed(struct virtio_net *dev,
2979 		     struct vhost_virtqueue *__rte_restrict vq,
2980 		     struct rte_mempool *mbuf_pool,
2981 		     struct rte_mbuf **__rte_restrict pkts,
2982 		     uint32_t count,
2983 		     bool legacy_ol_flags)
2984 {
2985 	uint32_t pkt_idx = 0;
2986 
2987 	if (rte_pktmbuf_alloc_bulk(mbuf_pool, pkts, count))
2988 		return 0;
2989 
2990 	do {
2991 		rte_prefetch0(&vq->desc_packed[vq->last_avail_idx]);
2992 
2993 		if (count - pkt_idx >= PACKED_BATCH_SIZE) {
2994 			if (!virtio_dev_tx_batch_packed(dev, vq,
2995 							&pkts[pkt_idx],
2996 							legacy_ol_flags)) {
2997 				pkt_idx += PACKED_BATCH_SIZE;
2998 				continue;
2999 			}
3000 		}
3001 
3002 		if (virtio_dev_tx_single_packed(dev, vq, mbuf_pool,
3003 						pkts[pkt_idx],
3004 						legacy_ol_flags))
3005 			break;
3006 		pkt_idx++;
3007 	} while (pkt_idx < count);
3008 
3009 	if (pkt_idx != count)
3010 		rte_pktmbuf_free_bulk(&pkts[pkt_idx], count - pkt_idx);
3011 
3012 	if (vq->shadow_used_idx) {
3013 		do_data_copy_dequeue(vq);
3014 
3015 		vhost_flush_dequeue_shadow_packed(dev, vq);
3016 		vhost_vring_call_packed(dev, vq);
3017 	}
3018 
3019 	return pkt_idx;
3020 }
3021 
3022 __rte_noinline
3023 static uint16_t
3024 virtio_dev_tx_packed_legacy(struct virtio_net *dev,
3025 	struct vhost_virtqueue *__rte_restrict vq, struct rte_mempool *mbuf_pool,
3026 	struct rte_mbuf **__rte_restrict pkts, uint32_t count)
3027 {
3028 	return virtio_dev_tx_packed(dev, vq, mbuf_pool, pkts, count, true);
3029 }
3030 
3031 __rte_noinline
3032 static uint16_t
3033 virtio_dev_tx_packed_compliant(struct virtio_net *dev,
3034 	struct vhost_virtqueue *__rte_restrict vq, struct rte_mempool *mbuf_pool,
3035 	struct rte_mbuf **__rte_restrict pkts, uint32_t count)
3036 {
3037 	return virtio_dev_tx_packed(dev, vq, mbuf_pool, pkts, count, false);
3038 }
3039 
3040 uint16_t
3041 rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
3042 	struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count)
3043 {
3044 	struct virtio_net *dev;
3045 	struct rte_mbuf *rarp_mbuf = NULL;
3046 	struct vhost_virtqueue *vq;
3047 	int16_t success = 1;
3048 
3049 	dev = get_device(vid);
3050 	if (!dev)
3051 		return 0;
3052 
3053 	if (unlikely(!(dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET))) {
3054 		VHOST_LOG_DATA(ERR, "(%s) %s: built-in vhost net backend is disabled.\n",
3055 				dev->ifname, __func__);
3056 		return 0;
3057 	}
3058 
3059 	if (unlikely(!is_valid_virt_queue_idx(queue_id, 1, dev->nr_vring))) {
3060 		VHOST_LOG_DATA(ERR, "(%s) %s: invalid virtqueue idx %d.\n",
3061 				dev->ifname, __func__, queue_id);
3062 		return 0;
3063 	}
3064 
3065 	vq = dev->virtqueue[queue_id];
3066 
3067 	if (unlikely(rte_spinlock_trylock(&vq->access_lock) == 0))
3068 		return 0;
3069 
3070 	if (unlikely(!vq->enabled)) {
3071 		count = 0;
3072 		goto out_access_unlock;
3073 	}
3074 
3075 	if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
3076 		vhost_user_iotlb_rd_lock(vq);
3077 
3078 	if (unlikely(!vq->access_ok))
3079 		if (unlikely(vring_translate(dev, vq) < 0)) {
3080 			count = 0;
3081 			goto out;
3082 		}
3083 
3084 	/*
3085 	 * Construct a RARP broadcast packet, and inject it to the "pkts"
3086 	 * array, to looks like that guest actually send such packet.
3087 	 *
3088 	 * Check user_send_rarp() for more information.
3089 	 *
3090 	 * broadcast_rarp shares a cacheline in the virtio_net structure
3091 	 * with some fields that are accessed during enqueue and
3092 	 * __atomic_compare_exchange_n causes a write if performed compare
3093 	 * and exchange. This could result in false sharing between enqueue
3094 	 * and dequeue.
3095 	 *
3096 	 * Prevent unnecessary false sharing by reading broadcast_rarp first
3097 	 * and only performing compare and exchange if the read indicates it
3098 	 * is likely to be set.
3099 	 */
3100 	if (unlikely(__atomic_load_n(&dev->broadcast_rarp, __ATOMIC_ACQUIRE) &&
3101 			__atomic_compare_exchange_n(&dev->broadcast_rarp,
3102 			&success, 0, 0, __ATOMIC_RELEASE, __ATOMIC_RELAXED))) {
3103 
3104 		rarp_mbuf = rte_net_make_rarp_packet(mbuf_pool, &dev->mac);
3105 		if (rarp_mbuf == NULL) {
3106 			VHOST_LOG_DATA(ERR, "(%s) failed to make RARP packet.\n", dev->ifname);
3107 			count = 0;
3108 			goto out;
3109 		}
3110 		/*
3111 		 * Inject it to the head of "pkts" array, so that switch's mac
3112 		 * learning table will get updated first.
3113 		 */
3114 		pkts[0] = rarp_mbuf;
3115 		pkts++;
3116 		count -= 1;
3117 	}
3118 
3119 	if (vq_is_packed(dev)) {
3120 		if (dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS)
3121 			count = virtio_dev_tx_packed_legacy(dev, vq, mbuf_pool, pkts, count);
3122 		else
3123 			count = virtio_dev_tx_packed_compliant(dev, vq, mbuf_pool, pkts, count);
3124 	} else {
3125 		if (dev->flags & VIRTIO_DEV_LEGACY_OL_FLAGS)
3126 			count = virtio_dev_tx_split_legacy(dev, vq, mbuf_pool, pkts, count);
3127 		else
3128 			count = virtio_dev_tx_split_compliant(dev, vq, mbuf_pool, pkts, count);
3129 	}
3130 
3131 out:
3132 	if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
3133 		vhost_user_iotlb_rd_unlock(vq);
3134 
3135 out_access_unlock:
3136 	rte_spinlock_unlock(&vq->access_lock);
3137 
3138 	if (unlikely(rarp_mbuf != NULL))
3139 		count += 1;
3140 
3141 	return count;
3142 }
3143