xref: /dpdk/drivers/net/virtio/virtio_rxtx_simple.c (revision a38dfe974b3b9ef7d961a9805a805a3ce7df9288)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright(c) 2010-2015 Intel Corporation. All rights reserved.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <stdint.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <errno.h>
39 
40 #include <tmmintrin.h>
41 
42 #include <rte_cycles.h>
43 #include <rte_memory.h>
44 #include <rte_memzone.h>
45 #include <rte_branch_prediction.h>
46 #include <rte_mempool.h>
47 #include <rte_malloc.h>
48 #include <rte_mbuf.h>
49 #include <rte_ether.h>
50 #include <rte_ethdev.h>
51 #include <rte_prefetch.h>
52 #include <rte_string_fns.h>
53 #include <rte_errno.h>
54 #include <rte_byteorder.h>
55 
56 #include "virtio_logs.h"
57 #include "virtio_ethdev.h"
58 #include "virtqueue.h"
59 #include "virtio_rxtx.h"
60 
61 #define RTE_VIRTIO_VPMD_RX_BURST 32
62 #define RTE_VIRTIO_DESC_PER_LOOP 8
63 #define RTE_VIRTIO_VPMD_RX_REARM_THRESH RTE_VIRTIO_VPMD_RX_BURST
64 
65 #ifndef __INTEL_COMPILER
66 #pragma GCC diagnostic ignored "-Wcast-qual"
67 #endif
68 
69 int __attribute__((cold))
70 virtqueue_enqueue_recv_refill_simple(struct virtqueue *vq,
71 	struct rte_mbuf *cookie)
72 {
73 	struct vq_desc_extra *dxp;
74 	struct vring_desc *start_dp;
75 	uint16_t desc_idx;
76 
77 	desc_idx = vq->vq_avail_idx & (vq->vq_nentries - 1);
78 	dxp = &vq->vq_descx[desc_idx];
79 	dxp->cookie = (void *)cookie;
80 	vq->sw_ring[desc_idx] = cookie;
81 
82 	start_dp = vq->vq_ring.desc;
83 	start_dp[desc_idx].addr = (uint64_t)((uintptr_t)cookie->buf_physaddr +
84 		RTE_PKTMBUF_HEADROOM - vq->hw->vtnet_hdr_size);
85 	start_dp[desc_idx].len = cookie->buf_len -
86 		RTE_PKTMBUF_HEADROOM + vq->hw->vtnet_hdr_size;
87 
88 	vq->vq_free_cnt--;
89 	vq->vq_avail_idx++;
90 
91 	return 0;
92 }
93 
94 static inline void
95 virtio_rxq_rearm_vec(struct virtqueue *rxvq)
96 {
97 	int i;
98 	uint16_t desc_idx;
99 	struct rte_mbuf **sw_ring;
100 	struct vring_desc *start_dp;
101 	int ret;
102 
103 	desc_idx = rxvq->vq_avail_idx & (rxvq->vq_nentries - 1);
104 	sw_ring = &rxvq->sw_ring[desc_idx];
105 	start_dp = &rxvq->vq_ring.desc[desc_idx];
106 
107 	ret = rte_mempool_get_bulk(rxvq->mpool, (void **)sw_ring,
108 		RTE_VIRTIO_VPMD_RX_REARM_THRESH);
109 	if (unlikely(ret)) {
110 		rte_eth_devices[rxvq->port_id].data->rx_mbuf_alloc_failed +=
111 			RTE_VIRTIO_VPMD_RX_REARM_THRESH;
112 		return;
113 	}
114 
115 	for (i = 0; i < RTE_VIRTIO_VPMD_RX_REARM_THRESH; i++) {
116 		uintptr_t p;
117 
118 		p = (uintptr_t)&sw_ring[i]->rearm_data;
119 		*(uint64_t *)p = rxvq->mbuf_initializer;
120 
121 		start_dp[i].addr =
122 			(uint64_t)((uintptr_t)sw_ring[i]->buf_physaddr +
123 			RTE_PKTMBUF_HEADROOM - rxvq->hw->vtnet_hdr_size);
124 		start_dp[i].len = sw_ring[i]->buf_len -
125 			RTE_PKTMBUF_HEADROOM + rxvq->hw->vtnet_hdr_size;
126 	}
127 
128 	rxvq->vq_avail_idx += RTE_VIRTIO_VPMD_RX_REARM_THRESH;
129 	rxvq->vq_free_cnt -= RTE_VIRTIO_VPMD_RX_REARM_THRESH;
130 	vq_update_avail_idx(rxvq);
131 }
132 
133 /* virtio vPMD receive routine, only accept(nb_pkts >= RTE_VIRTIO_DESC_PER_LOOP)
134  *
135  * This routine is for non-mergeable RX, one desc for each guest buffer.
136  * This routine is based on the RX ring layout optimization. Each entry in the
137  * avail ring points to the desc with the same index in the desc ring and this
138  * will never be changed in the driver.
139  *
140  * - nb_pkts < RTE_VIRTIO_DESC_PER_LOOP, just return no packet
141  */
142 uint16_t
143 virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
144 	uint16_t nb_pkts)
145 {
146 	struct virtqueue *rxvq = rx_queue;
147 	uint16_t nb_used;
148 	uint16_t desc_idx;
149 	struct vring_used_elem *rused;
150 	struct rte_mbuf **sw_ring;
151 	struct rte_mbuf **sw_ring_end;
152 	uint16_t nb_pkts_received;
153 	__m128i shuf_msk1, shuf_msk2, len_adjust;
154 
155 	shuf_msk1 = _mm_set_epi8(
156 		0xFF, 0xFF, 0xFF, 0xFF,
157 		0xFF, 0xFF,		/* vlan tci */
158 		5, 4,			/* dat len */
159 		0xFF, 0xFF, 5, 4,	/* pkt len */
160 		0xFF, 0xFF, 0xFF, 0xFF	/* packet type */
161 
162 	);
163 
164 	shuf_msk2 = _mm_set_epi8(
165 		0xFF, 0xFF, 0xFF, 0xFF,
166 		0xFF, 0xFF,		/* vlan tci */
167 		13, 12,			/* dat len */
168 		0xFF, 0xFF, 13, 12,	/* pkt len */
169 		0xFF, 0xFF, 0xFF, 0xFF	/* packet type */
170 	);
171 
172 	/* Subtract the header length.
173 	*  In which case do we need the header length in used->len ?
174 	*/
175 	len_adjust = _mm_set_epi16(
176 		0, 0,
177 		0,
178 		(uint16_t)-rxvq->hw->vtnet_hdr_size,
179 		0, (uint16_t)-rxvq->hw->vtnet_hdr_size,
180 		0, 0);
181 
182 	if (unlikely(nb_pkts < RTE_VIRTIO_DESC_PER_LOOP))
183 		return 0;
184 
185 	nb_used = *(volatile uint16_t *)&rxvq->vq_ring.used->idx -
186 		rxvq->vq_used_cons_idx;
187 
188 	rte_compiler_barrier();
189 
190 	if (unlikely(nb_used == 0))
191 		return 0;
192 
193 	nb_pkts = RTE_ALIGN_FLOOR(nb_pkts, RTE_VIRTIO_DESC_PER_LOOP);
194 	nb_used = RTE_MIN(nb_used, nb_pkts);
195 
196 	desc_idx = (uint16_t)(rxvq->vq_used_cons_idx & (rxvq->vq_nentries - 1));
197 	rused = &rxvq->vq_ring.used->ring[desc_idx];
198 	sw_ring  = &rxvq->sw_ring[desc_idx];
199 	sw_ring_end = &rxvq->sw_ring[rxvq->vq_nentries];
200 
201 	_mm_prefetch((const void *)rused, _MM_HINT_T0);
202 
203 	if (rxvq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
204 		virtio_rxq_rearm_vec(rxvq);
205 		if (unlikely(virtqueue_kick_prepare(rxvq)))
206 			virtqueue_notify(rxvq);
207 	}
208 
209 	for (nb_pkts_received = 0;
210 		nb_pkts_received < nb_used;) {
211 		__m128i desc[RTE_VIRTIO_DESC_PER_LOOP / 2];
212 		__m128i mbp[RTE_VIRTIO_DESC_PER_LOOP / 2];
213 		__m128i pkt_mb[RTE_VIRTIO_DESC_PER_LOOP];
214 
215 		mbp[0] = _mm_loadu_si128((__m128i *)(sw_ring + 0));
216 		desc[0] = _mm_loadu_si128((__m128i *)(rused + 0));
217 		_mm_storeu_si128((__m128i *)&rx_pkts[0], mbp[0]);
218 
219 		mbp[1] = _mm_loadu_si128((__m128i *)(sw_ring + 2));
220 		desc[1] = _mm_loadu_si128((__m128i *)(rused + 2));
221 		_mm_storeu_si128((__m128i *)&rx_pkts[2], mbp[1]);
222 
223 		mbp[2] = _mm_loadu_si128((__m128i *)(sw_ring + 4));
224 		desc[2] = _mm_loadu_si128((__m128i *)(rused + 4));
225 		_mm_storeu_si128((__m128i *)&rx_pkts[4], mbp[2]);
226 
227 		mbp[3] = _mm_loadu_si128((__m128i *)(sw_ring + 6));
228 		desc[3] = _mm_loadu_si128((__m128i *)(rused + 6));
229 		_mm_storeu_si128((__m128i *)&rx_pkts[6], mbp[3]);
230 
231 		pkt_mb[1] = _mm_shuffle_epi8(desc[0], shuf_msk2);
232 		pkt_mb[0] = _mm_shuffle_epi8(desc[0], shuf_msk1);
233 		pkt_mb[1] = _mm_add_epi16(pkt_mb[1], len_adjust);
234 		pkt_mb[0] = _mm_add_epi16(pkt_mb[0], len_adjust);
235 		_mm_storeu_si128((void *)&rx_pkts[1]->rx_descriptor_fields1,
236 			pkt_mb[1]);
237 		_mm_storeu_si128((void *)&rx_pkts[0]->rx_descriptor_fields1,
238 			pkt_mb[0]);
239 
240 		pkt_mb[3] = _mm_shuffle_epi8(desc[1], shuf_msk2);
241 		pkt_mb[2] = _mm_shuffle_epi8(desc[1], shuf_msk1);
242 		pkt_mb[3] = _mm_add_epi16(pkt_mb[3], len_adjust);
243 		pkt_mb[2] = _mm_add_epi16(pkt_mb[2], len_adjust);
244 		_mm_storeu_si128((void *)&rx_pkts[3]->rx_descriptor_fields1,
245 			pkt_mb[3]);
246 		_mm_storeu_si128((void *)&rx_pkts[2]->rx_descriptor_fields1,
247 			pkt_mb[2]);
248 
249 		pkt_mb[5] = _mm_shuffle_epi8(desc[2], shuf_msk2);
250 		pkt_mb[4] = _mm_shuffle_epi8(desc[2], shuf_msk1);
251 		pkt_mb[5] = _mm_add_epi16(pkt_mb[5], len_adjust);
252 		pkt_mb[4] = _mm_add_epi16(pkt_mb[4], len_adjust);
253 		_mm_storeu_si128((void *)&rx_pkts[5]->rx_descriptor_fields1,
254 			pkt_mb[5]);
255 		_mm_storeu_si128((void *)&rx_pkts[4]->rx_descriptor_fields1,
256 			pkt_mb[4]);
257 
258 		pkt_mb[7] = _mm_shuffle_epi8(desc[3], shuf_msk2);
259 		pkt_mb[6] = _mm_shuffle_epi8(desc[3], shuf_msk1);
260 		pkt_mb[7] = _mm_add_epi16(pkt_mb[7], len_adjust);
261 		pkt_mb[6] = _mm_add_epi16(pkt_mb[6], len_adjust);
262 		_mm_storeu_si128((void *)&rx_pkts[7]->rx_descriptor_fields1,
263 			pkt_mb[7]);
264 		_mm_storeu_si128((void *)&rx_pkts[6]->rx_descriptor_fields1,
265 			pkt_mb[6]);
266 
267 		if (unlikely(nb_used <= RTE_VIRTIO_DESC_PER_LOOP)) {
268 			if (sw_ring + nb_used <= sw_ring_end)
269 				nb_pkts_received += nb_used;
270 			else
271 				nb_pkts_received += sw_ring_end - sw_ring;
272 			break;
273 		} else {
274 			if (unlikely(sw_ring + RTE_VIRTIO_DESC_PER_LOOP >=
275 				sw_ring_end)) {
276 				nb_pkts_received += sw_ring_end - sw_ring;
277 				break;
278 			} else {
279 				nb_pkts_received += RTE_VIRTIO_DESC_PER_LOOP;
280 
281 				rx_pkts += RTE_VIRTIO_DESC_PER_LOOP;
282 				sw_ring += RTE_VIRTIO_DESC_PER_LOOP;
283 				rused   += RTE_VIRTIO_DESC_PER_LOOP;
284 				nb_used -= RTE_VIRTIO_DESC_PER_LOOP;
285 			}
286 		}
287 	}
288 
289 	rxvq->vq_used_cons_idx += nb_pkts_received;
290 	rxvq->vq_free_cnt += nb_pkts_received;
291 	rxvq->packets += nb_pkts_received;
292 	return nb_pkts_received;
293 }
294 
295 #define VIRTIO_TX_FREE_THRESH 32
296 #define VIRTIO_TX_MAX_FREE_BUF_SZ 32
297 #define VIRTIO_TX_FREE_NR 32
298 /* TODO: vq->tx_free_cnt could mean num of free slots so we could avoid shift */
299 static inline void
300 virtio_xmit_cleanup(struct virtqueue *vq)
301 {
302 	uint16_t i, desc_idx;
303 	int nb_free = 0;
304 	struct rte_mbuf *m, *free[VIRTIO_TX_MAX_FREE_BUF_SZ];
305 
306 	desc_idx = (uint16_t)(vq->vq_used_cons_idx &
307 		   ((vq->vq_nentries >> 1) - 1));
308 	m = (struct rte_mbuf *)vq->vq_descx[desc_idx++].cookie;
309 	m = __rte_pktmbuf_prefree_seg(m);
310 	if (likely(m != NULL)) {
311 		free[0] = m;
312 		nb_free = 1;
313 		for (i = 1; i < VIRTIO_TX_FREE_NR; i++) {
314 			m = (struct rte_mbuf *)vq->vq_descx[desc_idx++].cookie;
315 			m = __rte_pktmbuf_prefree_seg(m);
316 			if (likely(m != NULL)) {
317 				if (likely(m->pool == free[0]->pool))
318 					free[nb_free++] = m;
319 				else {
320 					rte_mempool_put_bulk(free[0]->pool,
321 						(void **)free, nb_free);
322 					free[0] = m;
323 					nb_free = 1;
324 				}
325 			}
326 		}
327 		rte_mempool_put_bulk(free[0]->pool, (void **)free, nb_free);
328 	} else {
329 		for (i = 1; i < VIRTIO_TX_FREE_NR; i++) {
330 			m = (struct rte_mbuf *)vq->vq_descx[desc_idx++].cookie;
331 			m = __rte_pktmbuf_prefree_seg(m);
332 			if (m != NULL)
333 				rte_mempool_put(m->pool, m);
334 		}
335 	}
336 
337 	vq->vq_used_cons_idx += VIRTIO_TX_FREE_NR;
338 	vq->vq_free_cnt += (VIRTIO_TX_FREE_NR << 1);
339 }
340 
341 uint16_t
342 virtio_xmit_pkts_simple(void *tx_queue, struct rte_mbuf **tx_pkts,
343 	uint16_t nb_pkts)
344 {
345 	struct virtqueue *txvq = tx_queue;
346 	uint16_t nb_used;
347 	uint16_t desc_idx;
348 	struct vring_desc *start_dp;
349 	uint16_t nb_tail, nb_commit;
350 	int i;
351 	uint16_t desc_idx_max = (txvq->vq_nentries >> 1) - 1;
352 
353 	nb_used = VIRTQUEUE_NUSED(txvq);
354 	rte_compiler_barrier();
355 
356 	if (nb_used >= VIRTIO_TX_FREE_THRESH)
357 		virtio_xmit_cleanup(tx_queue);
358 
359 	nb_commit = nb_pkts = RTE_MIN((txvq->vq_free_cnt >> 1), nb_pkts);
360 	desc_idx = (uint16_t) (txvq->vq_avail_idx & desc_idx_max);
361 	start_dp = txvq->vq_ring.desc;
362 	nb_tail = (uint16_t) (desc_idx_max + 1 - desc_idx);
363 
364 	if (nb_commit >= nb_tail) {
365 		for (i = 0; i < nb_tail; i++)
366 			txvq->vq_descx[desc_idx + i].cookie = tx_pkts[i];
367 		for (i = 0; i < nb_tail; i++) {
368 			start_dp[desc_idx].addr =
369 				rte_mbuf_data_dma_addr(*tx_pkts);
370 			start_dp[desc_idx].len = (*tx_pkts)->pkt_len;
371 			tx_pkts++;
372 			desc_idx++;
373 		}
374 		nb_commit -= nb_tail;
375 		desc_idx = 0;
376 	}
377 	for (i = 0; i < nb_commit; i++)
378 		txvq->vq_descx[desc_idx + i].cookie = tx_pkts[i];
379 	for (i = 0; i < nb_commit; i++) {
380 		start_dp[desc_idx].addr = rte_mbuf_data_dma_addr(*tx_pkts);
381 		start_dp[desc_idx].len = (*tx_pkts)->pkt_len;
382 		tx_pkts++;
383 		desc_idx++;
384 	}
385 
386 	rte_compiler_barrier();
387 
388 	txvq->vq_free_cnt -= (uint16_t)(nb_pkts << 1);
389 	txvq->vq_avail_idx += nb_pkts;
390 	txvq->vq_ring.avail->idx = txvq->vq_avail_idx;
391 	txvq->packets += nb_pkts;
392 
393 	if (likely(nb_pkts)) {
394 		if (unlikely(virtqueue_kick_prepare(txvq)))
395 			virtqueue_notify(txvq);
396 	}
397 
398 	return nb_pkts;
399 }
400 
401 int __attribute__((cold))
402 virtio_rxq_vec_setup(struct virtqueue *rxq)
403 {
404 	uintptr_t p;
405 	struct rte_mbuf mb_def = { .buf_addr = 0 }; /* zeroed mbuf */
406 
407 	mb_def.nb_segs = 1;
408 	mb_def.data_off = RTE_PKTMBUF_HEADROOM;
409 	mb_def.port = rxq->port_id;
410 	rte_mbuf_refcnt_set(&mb_def, 1);
411 
412 	/* prevent compiler reordering: rearm_data covers previous fields */
413 	rte_compiler_barrier();
414 	p = (uintptr_t)&mb_def.rearm_data;
415 	rxq->mbuf_initializer = *(uint64_t *)p;
416 
417 	return 0;
418 }
419