e30377c510cb093410ca2c3a02375fbcb117e719
[deb_dpdk.git] / drivers / net / virtio / virtio_rxtx.c
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright(c) 2010-2014 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 <rte_cycles.h>
41 #include <rte_memory.h>
42 #include <rte_memzone.h>
43 #include <rte_branch_prediction.h>
44 #include <rte_mempool.h>
45 #include <rte_malloc.h>
46 #include <rte_mbuf.h>
47 #include <rte_ether.h>
48 #include <rte_ethdev.h>
49 #include <rte_prefetch.h>
50 #include <rte_string_fns.h>
51 #include <rte_errno.h>
52 #include <rte_byteorder.h>
53 #include <rte_cpuflags.h>
54 #include <rte_net.h>
55 #include <rte_ip.h>
56 #include <rte_udp.h>
57 #include <rte_tcp.h>
58
59 #include "virtio_logs.h"
60 #include "virtio_ethdev.h"
61 #include "virtio_pci.h"
62 #include "virtqueue.h"
63 #include "virtio_rxtx.h"
64
65 #ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
66 #define VIRTIO_DUMP_PACKET(m, len) rte_pktmbuf_dump(stdout, m, len)
67 #else
68 #define  VIRTIO_DUMP_PACKET(m, len) do { } while (0)
69 #endif
70
71
72 #define VIRTIO_SIMPLE_FLAGS ((uint32_t)ETH_TXQ_FLAGS_NOMULTSEGS | \
73         ETH_TXQ_FLAGS_NOOFFLOADS)
74
75 int
76 virtio_dev_rx_queue_done(void *rxq, uint16_t offset)
77 {
78         struct virtnet_rx *rxvq = rxq;
79         struct virtqueue *vq = rxvq->vq;
80
81         return VIRTQUEUE_NUSED(vq) >= offset;
82 }
83
84 static void
85 vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx)
86 {
87         struct vring_desc *dp, *dp_tail;
88         struct vq_desc_extra *dxp;
89         uint16_t desc_idx_last = desc_idx;
90
91         dp  = &vq->vq_ring.desc[desc_idx];
92         dxp = &vq->vq_descx[desc_idx];
93         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt + dxp->ndescs);
94         if ((dp->flags & VRING_DESC_F_INDIRECT) == 0) {
95                 while (dp->flags & VRING_DESC_F_NEXT) {
96                         desc_idx_last = dp->next;
97                         dp = &vq->vq_ring.desc[dp->next];
98                 }
99         }
100         dxp->ndescs = 0;
101
102         /*
103          * We must append the existing free chain, if any, to the end of
104          * newly freed chain. If the virtqueue was completely used, then
105          * head would be VQ_RING_DESC_CHAIN_END (ASSERTed above).
106          */
107         if (vq->vq_desc_tail_idx == VQ_RING_DESC_CHAIN_END) {
108                 vq->vq_desc_head_idx = desc_idx;
109         } else {
110                 dp_tail = &vq->vq_ring.desc[vq->vq_desc_tail_idx];
111                 dp_tail->next = desc_idx;
112         }
113
114         vq->vq_desc_tail_idx = desc_idx_last;
115         dp->next = VQ_RING_DESC_CHAIN_END;
116 }
117
118 static uint16_t
119 virtqueue_dequeue_burst_rx(struct virtqueue *vq, struct rte_mbuf **rx_pkts,
120                            uint32_t *len, uint16_t num)
121 {
122         struct vring_used_elem *uep;
123         struct rte_mbuf *cookie;
124         uint16_t used_idx, desc_idx;
125         uint16_t i;
126
127         /*  Caller does the check */
128         for (i = 0; i < num ; i++) {
129                 used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
130                 uep = &vq->vq_ring.used->ring[used_idx];
131                 desc_idx = (uint16_t) uep->id;
132                 len[i] = uep->len;
133                 cookie = (struct rte_mbuf *)vq->vq_descx[desc_idx].cookie;
134
135                 if (unlikely(cookie == NULL)) {
136                         PMD_DRV_LOG(ERR, "vring descriptor with no mbuf cookie at %u",
137                                 vq->vq_used_cons_idx);
138                         break;
139                 }
140
141                 rte_prefetch0(cookie);
142                 rte_packet_prefetch(rte_pktmbuf_mtod(cookie, void *));
143                 rx_pkts[i]  = cookie;
144                 vq->vq_used_cons_idx++;
145                 vq_ring_free_chain(vq, desc_idx);
146                 vq->vq_descx[desc_idx].cookie = NULL;
147         }
148
149         return i;
150 }
151
152 #ifndef DEFAULT_TX_FREE_THRESH
153 #define DEFAULT_TX_FREE_THRESH 32
154 #endif
155
156 /* Cleanup from completed transmits. */
157 static void
158 virtio_xmit_cleanup(struct virtqueue *vq, uint16_t num)
159 {
160         uint16_t i, used_idx, desc_idx;
161         for (i = 0; i < num; i++) {
162                 struct vring_used_elem *uep;
163                 struct vq_desc_extra *dxp;
164
165                 used_idx = (uint16_t)(vq->vq_used_cons_idx & (vq->vq_nentries - 1));
166                 uep = &vq->vq_ring.used->ring[used_idx];
167
168                 desc_idx = (uint16_t) uep->id;
169                 dxp = &vq->vq_descx[desc_idx];
170                 vq->vq_used_cons_idx++;
171                 vq_ring_free_chain(vq, desc_idx);
172
173                 if (dxp->cookie != NULL) {
174                         rte_pktmbuf_free(dxp->cookie);
175                         dxp->cookie = NULL;
176                 }
177         }
178 }
179
180
181 static inline int
182 virtqueue_enqueue_recv_refill(struct virtqueue *vq, struct rte_mbuf *cookie)
183 {
184         struct vq_desc_extra *dxp;
185         struct virtio_hw *hw = vq->hw;
186         struct vring_desc *start_dp;
187         uint16_t needed = 1;
188         uint16_t head_idx, idx;
189
190         if (unlikely(vq->vq_free_cnt == 0))
191                 return -ENOSPC;
192         if (unlikely(vq->vq_free_cnt < needed))
193                 return -EMSGSIZE;
194
195         head_idx = vq->vq_desc_head_idx;
196         if (unlikely(head_idx >= vq->vq_nentries))
197                 return -EFAULT;
198
199         idx = head_idx;
200         dxp = &vq->vq_descx[idx];
201         dxp->cookie = (void *)cookie;
202         dxp->ndescs = needed;
203
204         start_dp = vq->vq_ring.desc;
205         start_dp[idx].addr =
206                 VIRTIO_MBUF_ADDR(cookie, vq) +
207                 RTE_PKTMBUF_HEADROOM - hw->vtnet_hdr_size;
208         start_dp[idx].len =
209                 cookie->buf_len - RTE_PKTMBUF_HEADROOM + hw->vtnet_hdr_size;
210         start_dp[idx].flags =  VRING_DESC_F_WRITE;
211         idx = start_dp[idx].next;
212         vq->vq_desc_head_idx = idx;
213         if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
214                 vq->vq_desc_tail_idx = idx;
215         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
216         vq_update_avail_ring(vq, head_idx);
217
218         return 0;
219 }
220
221 /* When doing TSO, the IP length is not included in the pseudo header
222  * checksum of the packet given to the PMD, but for virtio it is
223  * expected.
224  */
225 static void
226 virtio_tso_fix_cksum(struct rte_mbuf *m)
227 {
228         /* common case: header is not fragmented */
229         if (likely(rte_pktmbuf_data_len(m) >= m->l2_len + m->l3_len +
230                         m->l4_len)) {
231                 struct ipv4_hdr *iph;
232                 struct ipv6_hdr *ip6h;
233                 struct tcp_hdr *th;
234                 uint16_t prev_cksum, new_cksum, ip_len, ip_paylen;
235                 uint32_t tmp;
236
237                 iph = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *, m->l2_len);
238                 th = RTE_PTR_ADD(iph, m->l3_len);
239                 if ((iph->version_ihl >> 4) == 4) {
240                         iph->hdr_checksum = 0;
241                         iph->hdr_checksum = rte_ipv4_cksum(iph);
242                         ip_len = iph->total_length;
243                         ip_paylen = rte_cpu_to_be_16(rte_be_to_cpu_16(ip_len) -
244                                 m->l3_len);
245                 } else {
246                         ip6h = (struct ipv6_hdr *)iph;
247                         ip_paylen = ip6h->payload_len;
248                 }
249
250                 /* calculate the new phdr checksum not including ip_paylen */
251                 prev_cksum = th->cksum;
252                 tmp = prev_cksum;
253                 tmp += ip_paylen;
254                 tmp = (tmp & 0xffff) + (tmp >> 16);
255                 new_cksum = tmp;
256
257                 /* replace it in the packet */
258                 th->cksum = new_cksum;
259         }
260 }
261
262 static inline int
263 tx_offload_enabled(struct virtio_hw *hw)
264 {
265         return vtpci_with_feature(hw, VIRTIO_NET_F_CSUM) ||
266                 vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO4) ||
267                 vtpci_with_feature(hw, VIRTIO_NET_F_HOST_TSO6);
268 }
269
270 /* avoid write operation when necessary, to lessen cache issues */
271 #define ASSIGN_UNLESS_EQUAL(var, val) do {      \
272         if ((var) != (val))                     \
273                 (var) = (val);                  \
274 } while (0)
275
276 static inline void
277 virtqueue_enqueue_xmit(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
278                        uint16_t needed, int use_indirect, int can_push)
279 {
280         struct virtio_tx_region *txr = txvq->virtio_net_hdr_mz->addr;
281         struct vq_desc_extra *dxp;
282         struct virtqueue *vq = txvq->vq;
283         struct vring_desc *start_dp;
284         uint16_t seg_num = cookie->nb_segs;
285         uint16_t head_idx, idx;
286         uint16_t head_size = vq->hw->vtnet_hdr_size;
287         struct virtio_net_hdr *hdr;
288         int offload;
289
290         offload = tx_offload_enabled(vq->hw);
291         head_idx = vq->vq_desc_head_idx;
292         idx = head_idx;
293         dxp = &vq->vq_descx[idx];
294         dxp->cookie = (void *)cookie;
295         dxp->ndescs = needed;
296
297         start_dp = vq->vq_ring.desc;
298
299         if (can_push) {
300                 /* prepend cannot fail, checked by caller */
301                 hdr = (struct virtio_net_hdr *)
302                         rte_pktmbuf_prepend(cookie, head_size);
303                 /* if offload disabled, it is not zeroed below, do it now */
304                 if (offload == 0) {
305                         ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0);
306                         ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0);
307                         ASSIGN_UNLESS_EQUAL(hdr->flags, 0);
308                         ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0);
309                         ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0);
310                         ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0);
311                 }
312         } else if (use_indirect) {
313                 /* setup tx ring slot to point to indirect
314                  * descriptor list stored in reserved region.
315                  *
316                  * the first slot in indirect ring is already preset
317                  * to point to the header in reserved region
318                  */
319                 start_dp[idx].addr  = txvq->virtio_net_hdr_mem +
320                         RTE_PTR_DIFF(&txr[idx].tx_indir, txr);
321                 start_dp[idx].len   = (seg_num + 1) * sizeof(struct vring_desc);
322                 start_dp[idx].flags = VRING_DESC_F_INDIRECT;
323                 hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
324
325                 /* loop below will fill in rest of the indirect elements */
326                 start_dp = txr[idx].tx_indir;
327                 idx = 1;
328         } else {
329                 /* setup first tx ring slot to point to header
330                  * stored in reserved region.
331                  */
332                 start_dp[idx].addr  = txvq->virtio_net_hdr_mem +
333                         RTE_PTR_DIFF(&txr[idx].tx_hdr, txr);
334                 start_dp[idx].len   = vq->hw->vtnet_hdr_size;
335                 start_dp[idx].flags = VRING_DESC_F_NEXT;
336                 hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
337
338                 idx = start_dp[idx].next;
339         }
340
341         /* Checksum Offload / TSO */
342         if (offload) {
343                 if (cookie->ol_flags & PKT_TX_TCP_SEG)
344                         cookie->ol_flags |= PKT_TX_TCP_CKSUM;
345
346                 switch (cookie->ol_flags & PKT_TX_L4_MASK) {
347                 case PKT_TX_UDP_CKSUM:
348                         hdr->csum_start = cookie->l2_len + cookie->l3_len;
349                         hdr->csum_offset = offsetof(struct udp_hdr,
350                                 dgram_cksum);
351                         hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
352                         break;
353
354                 case PKT_TX_TCP_CKSUM:
355                         hdr->csum_start = cookie->l2_len + cookie->l3_len;
356                         hdr->csum_offset = offsetof(struct tcp_hdr, cksum);
357                         hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
358                         break;
359
360                 default:
361                         ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0);
362                         ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0);
363                         ASSIGN_UNLESS_EQUAL(hdr->flags, 0);
364                         break;
365                 }
366
367                 /* TCP Segmentation Offload */
368                 if (cookie->ol_flags & PKT_TX_TCP_SEG) {
369                         virtio_tso_fix_cksum(cookie);
370                         hdr->gso_type = (cookie->ol_flags & PKT_TX_IPV6) ?
371                                 VIRTIO_NET_HDR_GSO_TCPV6 :
372                                 VIRTIO_NET_HDR_GSO_TCPV4;
373                         hdr->gso_size = cookie->tso_segsz;
374                         hdr->hdr_len =
375                                 cookie->l2_len +
376                                 cookie->l3_len +
377                                 cookie->l4_len;
378                 } else {
379                         ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0);
380                         ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0);
381                         ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0);
382                 }
383         }
384
385         do {
386                 start_dp[idx].addr  = VIRTIO_MBUF_DATA_DMA_ADDR(cookie, vq);
387                 start_dp[idx].len   = cookie->data_len;
388                 start_dp[idx].flags = cookie->next ? VRING_DESC_F_NEXT : 0;
389                 idx = start_dp[idx].next;
390         } while ((cookie = cookie->next) != NULL);
391
392         if (use_indirect)
393                 idx = vq->vq_ring.desc[head_idx].next;
394
395         vq->vq_desc_head_idx = idx;
396         if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
397                 vq->vq_desc_tail_idx = idx;
398         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
399         vq_update_avail_ring(vq, head_idx);
400 }
401
402 void
403 virtio_dev_cq_start(struct rte_eth_dev *dev)
404 {
405         struct virtio_hw *hw = dev->data->dev_private;
406
407         if (hw->cvq && hw->cvq->vq) {
408                 VIRTQUEUE_DUMP((struct virtqueue *)hw->cvq->vq);
409         }
410 }
411
412 int
413 virtio_dev_rx_queue_setup(struct rte_eth_dev *dev,
414                         uint16_t queue_idx,
415                         uint16_t nb_desc,
416                         unsigned int socket_id __rte_unused,
417                         __rte_unused const struct rte_eth_rxconf *rx_conf,
418                         struct rte_mempool *mp)
419 {
420         uint16_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_RQ_QUEUE_IDX;
421         struct virtio_hw *hw = dev->data->dev_private;
422         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
423         struct virtnet_rx *rxvq;
424         int error, nbufs;
425         struct rte_mbuf *m;
426         uint16_t desc_idx;
427
428         PMD_INIT_FUNC_TRACE();
429
430         if (nb_desc == 0 || nb_desc > vq->vq_nentries)
431                 nb_desc = vq->vq_nentries;
432         vq->vq_free_cnt = RTE_MIN(vq->vq_free_cnt, nb_desc);
433
434         rxvq = &vq->rxq;
435         rxvq->queue_id = queue_idx;
436         rxvq->mpool = mp;
437         if (rxvq->mpool == NULL) {
438                 rte_exit(EXIT_FAILURE,
439                         "Cannot allocate mbufs for rx virtqueue");
440         }
441         dev->data->rx_queues[queue_idx] = rxvq;
442
443
444         /* Allocate blank mbufs for the each rx descriptor */
445         nbufs = 0;
446         error = ENOSPC;
447
448         if (hw->use_simple_rxtx) {
449                 for (desc_idx = 0; desc_idx < vq->vq_nentries;
450                      desc_idx++) {
451                         vq->vq_ring.avail->ring[desc_idx] = desc_idx;
452                         vq->vq_ring.desc[desc_idx].flags =
453                                 VRING_DESC_F_WRITE;
454                 }
455         }
456
457         memset(&rxvq->fake_mbuf, 0, sizeof(rxvq->fake_mbuf));
458         for (desc_idx = 0; desc_idx < RTE_PMD_VIRTIO_RX_MAX_BURST;
459              desc_idx++) {
460                 vq->sw_ring[vq->vq_nentries + desc_idx] =
461                         &rxvq->fake_mbuf;
462         }
463
464         while (!virtqueue_full(vq)) {
465                 m = rte_mbuf_raw_alloc(rxvq->mpool);
466                 if (m == NULL)
467                         break;
468
469                 /* Enqueue allocated buffers */
470                 if (hw->use_simple_rxtx)
471                         error = virtqueue_enqueue_recv_refill_simple(vq, m);
472                 else
473                         error = virtqueue_enqueue_recv_refill(vq, m);
474
475                 if (error) {
476                         rte_pktmbuf_free(m);
477                         break;
478                 }
479                 nbufs++;
480         }
481
482         vq_update_avail_idx(vq);
483
484         PMD_INIT_LOG(DEBUG, "Allocated %d bufs", nbufs);
485
486         virtio_rxq_vec_setup(rxvq);
487
488         VIRTQUEUE_DUMP(vq);
489
490         return 0;
491 }
492
493 static void
494 virtio_update_rxtx_handler(struct rte_eth_dev *dev,
495                            const struct rte_eth_txconf *tx_conf)
496 {
497         uint8_t use_simple_rxtx = 0;
498         struct virtio_hw *hw = dev->data->dev_private;
499
500 #if defined RTE_ARCH_X86
501         if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE3))
502                 use_simple_rxtx = 1;
503 #elif defined RTE_ARCH_ARM64 || defined CONFIG_RTE_ARCH_ARM
504         if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_NEON))
505                 use_simple_rxtx = 1;
506 #endif
507         /* Use simple rx/tx func if single segment and no offloads */
508         if (use_simple_rxtx &&
509             (tx_conf->txq_flags & VIRTIO_SIMPLE_FLAGS) == VIRTIO_SIMPLE_FLAGS &&
510             !vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF)) {
511                 PMD_INIT_LOG(INFO, "Using simple rx/tx path");
512                 dev->tx_pkt_burst = virtio_xmit_pkts_simple;
513                 dev->rx_pkt_burst = virtio_recv_pkts_vec;
514                 hw->use_simple_rxtx = use_simple_rxtx;
515         }
516 }
517
518 /*
519  * struct rte_eth_dev *dev: Used to update dev
520  * uint16_t nb_desc: Defaults to values read from config space
521  * unsigned int socket_id: Used to allocate memzone
522  * const struct rte_eth_txconf *tx_conf: Used to setup tx engine
523  * uint16_t queue_idx: Just used as an index in dev txq list
524  */
525 int
526 virtio_dev_tx_queue_setup(struct rte_eth_dev *dev,
527                         uint16_t queue_idx,
528                         uint16_t nb_desc,
529                         unsigned int socket_id __rte_unused,
530                         const struct rte_eth_txconf *tx_conf)
531 {
532         uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_TQ_QUEUE_IDX;
533         struct virtio_hw *hw = dev->data->dev_private;
534         struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
535         struct virtnet_tx *txvq;
536         uint16_t tx_free_thresh;
537         uint16_t desc_idx;
538
539         PMD_INIT_FUNC_TRACE();
540
541         virtio_update_rxtx_handler(dev, tx_conf);
542
543         if (nb_desc == 0 || nb_desc > vq->vq_nentries)
544                 nb_desc = vq->vq_nentries;
545         vq->vq_free_cnt = RTE_MIN(vq->vq_free_cnt, nb_desc);
546
547         txvq = &vq->txq;
548         txvq->queue_id = queue_idx;
549
550         tx_free_thresh = tx_conf->tx_free_thresh;
551         if (tx_free_thresh == 0)
552                 tx_free_thresh =
553                         RTE_MIN(vq->vq_nentries / 4, DEFAULT_TX_FREE_THRESH);
554
555         if (tx_free_thresh >= (vq->vq_nentries - 3)) {
556                 RTE_LOG(ERR, PMD, "tx_free_thresh must be less than the "
557                         "number of TX entries minus 3 (%u)."
558                         " (tx_free_thresh=%u port=%u queue=%u)\n",
559                         vq->vq_nentries - 3,
560                         tx_free_thresh, dev->data->port_id, queue_idx);
561                 return -EINVAL;
562         }
563
564         vq->vq_free_thresh = tx_free_thresh;
565
566         if (hw->use_simple_rxtx) {
567                 uint16_t mid_idx  = vq->vq_nentries >> 1;
568
569                 for (desc_idx = 0; desc_idx < mid_idx; desc_idx++) {
570                         vq->vq_ring.avail->ring[desc_idx] =
571                                 desc_idx + mid_idx;
572                         vq->vq_ring.desc[desc_idx + mid_idx].next =
573                                 desc_idx;
574                         vq->vq_ring.desc[desc_idx + mid_idx].addr =
575                                 txvq->virtio_net_hdr_mem +
576                                 offsetof(struct virtio_tx_region, tx_hdr);
577                         vq->vq_ring.desc[desc_idx + mid_idx].len =
578                                 vq->hw->vtnet_hdr_size;
579                         vq->vq_ring.desc[desc_idx + mid_idx].flags =
580                                 VRING_DESC_F_NEXT;
581                         vq->vq_ring.desc[desc_idx].flags = 0;
582                 }
583                 for (desc_idx = mid_idx; desc_idx < vq->vq_nentries;
584                      desc_idx++)
585                         vq->vq_ring.avail->ring[desc_idx] = desc_idx;
586         }
587
588         VIRTQUEUE_DUMP(vq);
589
590         dev->data->tx_queues[queue_idx] = txvq;
591         return 0;
592 }
593
594 static void
595 virtio_discard_rxbuf(struct virtqueue *vq, struct rte_mbuf *m)
596 {
597         int error;
598         /*
599          * Requeue the discarded mbuf. This should always be
600          * successful since it was just dequeued.
601          */
602         error = virtqueue_enqueue_recv_refill(vq, m);
603         if (unlikely(error)) {
604                 RTE_LOG(ERR, PMD, "cannot requeue discarded mbuf");
605                 rte_pktmbuf_free(m);
606         }
607 }
608
609 static void
610 virtio_update_packet_stats(struct virtnet_stats *stats, struct rte_mbuf *mbuf)
611 {
612         uint32_t s = mbuf->pkt_len;
613         struct ether_addr *ea;
614
615         if (s == 64) {
616                 stats->size_bins[1]++;
617         } else if (s > 64 && s < 1024) {
618                 uint32_t bin;
619
620                 /* count zeros, and offset into correct bin */
621                 bin = (sizeof(s) * 8) - __builtin_clz(s) - 5;
622                 stats->size_bins[bin]++;
623         } else {
624                 if (s < 64)
625                         stats->size_bins[0]++;
626                 else if (s < 1519)
627                         stats->size_bins[6]++;
628                 else if (s >= 1519)
629                         stats->size_bins[7]++;
630         }
631
632         ea = rte_pktmbuf_mtod(mbuf, struct ether_addr *);
633         if (is_multicast_ether_addr(ea)) {
634                 if (is_broadcast_ether_addr(ea))
635                         stats->broadcast++;
636                 else
637                         stats->multicast++;
638         }
639 }
640
641 /* Optionally fill offload information in structure */
642 static int
643 virtio_rx_offload(struct rte_mbuf *m, struct virtio_net_hdr *hdr)
644 {
645         struct rte_net_hdr_lens hdr_lens;
646         uint32_t hdrlen, ptype;
647         int l4_supported = 0;
648
649         /* nothing to do */
650         if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
651                 return 0;
652
653         m->ol_flags |= PKT_RX_IP_CKSUM_UNKNOWN;
654
655         ptype = rte_net_get_ptype(m, &hdr_lens, RTE_PTYPE_ALL_MASK);
656         m->packet_type = ptype;
657         if ((ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_TCP ||
658             (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_UDP ||
659             (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_SCTP)
660                 l4_supported = 1;
661
662         if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
663                 hdrlen = hdr_lens.l2_len + hdr_lens.l3_len + hdr_lens.l4_len;
664                 if (hdr->csum_start <= hdrlen && l4_supported) {
665                         m->ol_flags |= PKT_RX_L4_CKSUM_NONE;
666                 } else {
667                         /* Unknown proto or tunnel, do sw cksum. We can assume
668                          * the cksum field is in the first segment since the
669                          * buffers we provided to the host are large enough.
670                          * In case of SCTP, this will be wrong since it's a CRC
671                          * but there's nothing we can do.
672                          */
673                         uint16_t csum, off;
674
675                         rte_raw_cksum_mbuf(m, hdr->csum_start,
676                                 rte_pktmbuf_pkt_len(m) - hdr->csum_start,
677                                 &csum);
678                         if (likely(csum != 0xffff))
679                                 csum = ~csum;
680                         off = hdr->csum_offset + hdr->csum_start;
681                         if (rte_pktmbuf_data_len(m) >= off + 1)
682                                 *rte_pktmbuf_mtod_offset(m, uint16_t *,
683                                         off) = csum;
684                 }
685         } else if (hdr->flags & VIRTIO_NET_HDR_F_DATA_VALID && l4_supported) {
686                 m->ol_flags |= PKT_RX_L4_CKSUM_GOOD;
687         }
688
689         /* GSO request, save required information in mbuf */
690         if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
691                 /* Check unsupported modes */
692                 if ((hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) ||
693                     (hdr->gso_size == 0)) {
694                         return -EINVAL;
695                 }
696
697                 /* Update mss lengthes in mbuf */
698                 m->tso_segsz = hdr->gso_size;
699                 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
700                         case VIRTIO_NET_HDR_GSO_TCPV4:
701                         case VIRTIO_NET_HDR_GSO_TCPV6:
702                                 m->ol_flags |= PKT_RX_LRO | \
703                                         PKT_RX_L4_CKSUM_NONE;
704                                 break;
705                         default:
706                                 return -EINVAL;
707                 }
708         }
709
710         return 0;
711 }
712
713 static inline int
714 rx_offload_enabled(struct virtio_hw *hw)
715 {
716         return vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_CSUM) ||
717                 vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO4) ||
718                 vtpci_with_feature(hw, VIRTIO_NET_F_GUEST_TSO6);
719 }
720
721 #define VIRTIO_MBUF_BURST_SZ 64
722 #define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc))
723 uint16_t
724 virtio_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
725 {
726         struct virtnet_rx *rxvq = rx_queue;
727         struct virtqueue *vq = rxvq->vq;
728         struct virtio_hw *hw = vq->hw;
729         struct rte_mbuf *rxm, *new_mbuf;
730         uint16_t nb_used, num, nb_rx;
731         uint32_t len[VIRTIO_MBUF_BURST_SZ];
732         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
733         int error;
734         uint32_t i, nb_enqueued;
735         uint32_t hdr_size;
736         int offload;
737         struct virtio_net_hdr *hdr;
738
739         nb_rx = 0;
740         if (unlikely(hw->started == 0))
741                 return nb_rx;
742
743         nb_used = VIRTQUEUE_NUSED(vq);
744
745         virtio_rmb();
746
747         num = likely(nb_used <= nb_pkts) ? nb_used : nb_pkts;
748         if (unlikely(num > VIRTIO_MBUF_BURST_SZ))
749                 num = VIRTIO_MBUF_BURST_SZ;
750         if (likely(num > DESC_PER_CACHELINE))
751                 num = num - ((vq->vq_used_cons_idx + num) % DESC_PER_CACHELINE);
752
753         num = virtqueue_dequeue_burst_rx(vq, rcv_pkts, len, num);
754         PMD_RX_LOG(DEBUG, "used:%d dequeue:%d", nb_used, num);
755
756         nb_enqueued = 0;
757         hdr_size = hw->vtnet_hdr_size;
758         offload = rx_offload_enabled(hw);
759
760         for (i = 0; i < num ; i++) {
761                 rxm = rcv_pkts[i];
762
763                 PMD_RX_LOG(DEBUG, "packet len:%d", len[i]);
764
765                 if (unlikely(len[i] < hdr_size + ETHER_HDR_LEN)) {
766                         PMD_RX_LOG(ERR, "Packet drop");
767                         nb_enqueued++;
768                         virtio_discard_rxbuf(vq, rxm);
769                         rxvq->stats.errors++;
770                         continue;
771                 }
772
773                 rxm->port = rxvq->port_id;
774                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
775                 rxm->ol_flags = 0;
776                 rxm->vlan_tci = 0;
777
778                 rxm->pkt_len = (uint32_t)(len[i] - hdr_size);
779                 rxm->data_len = (uint16_t)(len[i] - hdr_size);
780
781                 hdr = (struct virtio_net_hdr *)((char *)rxm->buf_addr +
782                         RTE_PKTMBUF_HEADROOM - hdr_size);
783
784                 if (hw->vlan_strip)
785                         rte_vlan_strip(rxm);
786
787                 if (offload && virtio_rx_offload(rxm, hdr) < 0) {
788                         virtio_discard_rxbuf(vq, rxm);
789                         rxvq->stats.errors++;
790                         continue;
791                 }
792
793                 VIRTIO_DUMP_PACKET(rxm, rxm->data_len);
794
795                 rx_pkts[nb_rx++] = rxm;
796
797                 rxvq->stats.bytes += rxm->pkt_len;
798                 virtio_update_packet_stats(&rxvq->stats, rxm);
799         }
800
801         rxvq->stats.packets += nb_rx;
802
803         /* Allocate new mbuf for the used descriptor */
804         error = ENOSPC;
805         while (likely(!virtqueue_full(vq))) {
806                 new_mbuf = rte_mbuf_raw_alloc(rxvq->mpool);
807                 if (unlikely(new_mbuf == NULL)) {
808                         struct rte_eth_dev *dev
809                                 = &rte_eth_devices[rxvq->port_id];
810                         dev->data->rx_mbuf_alloc_failed++;
811                         break;
812                 }
813                 error = virtqueue_enqueue_recv_refill(vq, new_mbuf);
814                 if (unlikely(error)) {
815                         rte_pktmbuf_free(new_mbuf);
816                         break;
817                 }
818                 nb_enqueued++;
819         }
820
821         if (likely(nb_enqueued)) {
822                 vq_update_avail_idx(vq);
823
824                 if (unlikely(virtqueue_kick_prepare(vq))) {
825                         virtqueue_notify(vq);
826                         PMD_RX_LOG(DEBUG, "Notified");
827                 }
828         }
829
830         return nb_rx;
831 }
832
833 uint16_t
834 virtio_recv_mergeable_pkts(void *rx_queue,
835                         struct rte_mbuf **rx_pkts,
836                         uint16_t nb_pkts)
837 {
838         struct virtnet_rx *rxvq = rx_queue;
839         struct virtqueue *vq = rxvq->vq;
840         struct virtio_hw *hw = vq->hw;
841         struct rte_mbuf *rxm, *new_mbuf;
842         uint16_t nb_used, num, nb_rx;
843         uint32_t len[VIRTIO_MBUF_BURST_SZ];
844         struct rte_mbuf *rcv_pkts[VIRTIO_MBUF_BURST_SZ];
845         struct rte_mbuf *prev;
846         int error;
847         uint32_t i, nb_enqueued;
848         uint32_t seg_num;
849         uint16_t extra_idx;
850         uint32_t seg_res;
851         uint32_t hdr_size;
852         int offload;
853
854         nb_rx = 0;
855         if (unlikely(hw->started == 0))
856                 return nb_rx;
857
858         nb_used = VIRTQUEUE_NUSED(vq);
859
860         virtio_rmb();
861
862         PMD_RX_LOG(DEBUG, "used:%d", nb_used);
863
864         i = 0;
865         nb_enqueued = 0;
866         seg_num = 0;
867         extra_idx = 0;
868         seg_res = 0;
869         hdr_size = hw->vtnet_hdr_size;
870         offload = rx_offload_enabled(hw);
871
872         while (i < nb_used) {
873                 struct virtio_net_hdr_mrg_rxbuf *header;
874
875                 if (nb_rx == nb_pkts)
876                         break;
877
878                 num = virtqueue_dequeue_burst_rx(vq, rcv_pkts, len, 1);
879                 if (num != 1)
880                         continue;
881
882                 i++;
883
884                 PMD_RX_LOG(DEBUG, "dequeue:%d", num);
885                 PMD_RX_LOG(DEBUG, "packet len:%d", len[0]);
886
887                 rxm = rcv_pkts[0];
888
889                 if (unlikely(len[0] < hdr_size + ETHER_HDR_LEN)) {
890                         PMD_RX_LOG(ERR, "Packet drop");
891                         nb_enqueued++;
892                         virtio_discard_rxbuf(vq, rxm);
893                         rxvq->stats.errors++;
894                         continue;
895                 }
896
897                 header = (struct virtio_net_hdr_mrg_rxbuf *)((char *)rxm->buf_addr +
898                         RTE_PKTMBUF_HEADROOM - hdr_size);
899                 seg_num = header->num_buffers;
900
901                 if (seg_num == 0)
902                         seg_num = 1;
903
904                 rxm->data_off = RTE_PKTMBUF_HEADROOM;
905                 rxm->nb_segs = seg_num;
906                 rxm->ol_flags = 0;
907                 rxm->vlan_tci = 0;
908                 rxm->pkt_len = (uint32_t)(len[0] - hdr_size);
909                 rxm->data_len = (uint16_t)(len[0] - hdr_size);
910
911                 rxm->port = rxvq->port_id;
912                 rx_pkts[nb_rx] = rxm;
913                 prev = rxm;
914
915                 if (offload && virtio_rx_offload(rxm, &header->hdr) < 0) {
916                         virtio_discard_rxbuf(vq, rxm);
917                         rxvq->stats.errors++;
918                         continue;
919                 }
920
921                 seg_res = seg_num - 1;
922
923                 while (seg_res != 0) {
924                         /*
925                          * Get extra segments for current uncompleted packet.
926                          */
927                         uint16_t  rcv_cnt =
928                                 RTE_MIN(seg_res, RTE_DIM(rcv_pkts));
929                         if (likely(VIRTQUEUE_NUSED(vq) >= rcv_cnt)) {
930                                 uint32_t rx_num =
931                                         virtqueue_dequeue_burst_rx(vq,
932                                         rcv_pkts, len, rcv_cnt);
933                                 i += rx_num;
934                                 rcv_cnt = rx_num;
935                         } else {
936                                 PMD_RX_LOG(ERR,
937                                            "No enough segments for packet.");
938                                 nb_enqueued++;
939                                 virtio_discard_rxbuf(vq, rxm);
940                                 rxvq->stats.errors++;
941                                 break;
942                         }
943
944                         extra_idx = 0;
945
946                         while (extra_idx < rcv_cnt) {
947                                 rxm = rcv_pkts[extra_idx];
948
949                                 rxm->data_off = RTE_PKTMBUF_HEADROOM - hdr_size;
950                                 rxm->pkt_len = (uint32_t)(len[extra_idx]);
951                                 rxm->data_len = (uint16_t)(len[extra_idx]);
952
953                                 if (prev)
954                                         prev->next = rxm;
955
956                                 prev = rxm;
957                                 rx_pkts[nb_rx]->pkt_len += rxm->pkt_len;
958                                 extra_idx++;
959                         };
960                         seg_res -= rcv_cnt;
961                 }
962
963                 if (hw->vlan_strip)
964                         rte_vlan_strip(rx_pkts[nb_rx]);
965
966                 VIRTIO_DUMP_PACKET(rx_pkts[nb_rx],
967                         rx_pkts[nb_rx]->data_len);
968
969                 rxvq->stats.bytes += rx_pkts[nb_rx]->pkt_len;
970                 virtio_update_packet_stats(&rxvq->stats, rx_pkts[nb_rx]);
971                 nb_rx++;
972         }
973
974         rxvq->stats.packets += nb_rx;
975
976         /* Allocate new mbuf for the used descriptor */
977         error = ENOSPC;
978         while (likely(!virtqueue_full(vq))) {
979                 new_mbuf = rte_mbuf_raw_alloc(rxvq->mpool);
980                 if (unlikely(new_mbuf == NULL)) {
981                         struct rte_eth_dev *dev
982                                 = &rte_eth_devices[rxvq->port_id];
983                         dev->data->rx_mbuf_alloc_failed++;
984                         break;
985                 }
986                 error = virtqueue_enqueue_recv_refill(vq, new_mbuf);
987                 if (unlikely(error)) {
988                         rte_pktmbuf_free(new_mbuf);
989                         break;
990                 }
991                 nb_enqueued++;
992         }
993
994         if (likely(nb_enqueued)) {
995                 vq_update_avail_idx(vq);
996
997                 if (unlikely(virtqueue_kick_prepare(vq))) {
998                         virtqueue_notify(vq);
999                         PMD_RX_LOG(DEBUG, "Notified");
1000                 }
1001         }
1002
1003         return nb_rx;
1004 }
1005
1006 uint16_t
1007 virtio_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
1008 {
1009         struct virtnet_tx *txvq = tx_queue;
1010         struct virtqueue *vq = txvq->vq;
1011         struct virtio_hw *hw = vq->hw;
1012         uint16_t hdr_size = hw->vtnet_hdr_size;
1013         uint16_t nb_used, nb_tx = 0;
1014         int error;
1015
1016         if (unlikely(hw->started == 0))
1017                 return nb_tx;
1018
1019         if (unlikely(nb_pkts < 1))
1020                 return nb_pkts;
1021
1022         PMD_TX_LOG(DEBUG, "%d packets to xmit", nb_pkts);
1023         nb_used = VIRTQUEUE_NUSED(vq);
1024
1025         virtio_rmb();
1026         if (likely(nb_used > vq->vq_nentries - vq->vq_free_thresh))
1027                 virtio_xmit_cleanup(vq, nb_used);
1028
1029         for (nb_tx = 0; nb_tx < nb_pkts; nb_tx++) {
1030                 struct rte_mbuf *txm = tx_pkts[nb_tx];
1031                 int can_push = 0, use_indirect = 0, slots, need;
1032
1033                 /* Do VLAN tag insertion */
1034                 if (unlikely(txm->ol_flags & PKT_TX_VLAN_PKT)) {
1035                         error = rte_vlan_insert(&txm);
1036                         if (unlikely(error)) {
1037                                 rte_pktmbuf_free(txm);
1038                                 continue;
1039                         }
1040                 }
1041
1042                 /* optimize ring usage */
1043                 if ((vtpci_with_feature(hw, VIRTIO_F_ANY_LAYOUT) ||
1044                       vtpci_with_feature(hw, VIRTIO_F_VERSION_1)) &&
1045                     rte_mbuf_refcnt_read(txm) == 1 &&
1046                     RTE_MBUF_DIRECT(txm) &&
1047                     txm->nb_segs == 1 &&
1048                     rte_pktmbuf_headroom(txm) >= hdr_size &&
1049                     rte_is_aligned(rte_pktmbuf_mtod(txm, char *),
1050                                    __alignof__(struct virtio_net_hdr_mrg_rxbuf)))
1051                         can_push = 1;
1052                 else if (vtpci_with_feature(hw, VIRTIO_RING_F_INDIRECT_DESC) &&
1053                          txm->nb_segs < VIRTIO_MAX_TX_INDIRECT)
1054                         use_indirect = 1;
1055
1056                 /* How many main ring entries are needed to this Tx?
1057                  * any_layout => number of segments
1058                  * indirect   => 1
1059                  * default    => number of segments + 1
1060                  */
1061                 slots = use_indirect ? 1 : (txm->nb_segs + !can_push);
1062                 need = slots - vq->vq_free_cnt;
1063
1064                 /* Positive value indicates it need free vring descriptors */
1065                 if (unlikely(need > 0)) {
1066                         nb_used = VIRTQUEUE_NUSED(vq);
1067                         virtio_rmb();
1068                         need = RTE_MIN(need, (int)nb_used);
1069
1070                         virtio_xmit_cleanup(vq, need);
1071                         need = slots - vq->vq_free_cnt;
1072                         if (unlikely(need > 0)) {
1073                                 PMD_TX_LOG(ERR,
1074                                            "No free tx descriptors to transmit");
1075                                 break;
1076                         }
1077                 }
1078
1079                 /* Enqueue Packet buffers */
1080                 virtqueue_enqueue_xmit(txvq, txm, slots, use_indirect, can_push);
1081
1082                 txvq->stats.bytes += txm->pkt_len;
1083                 virtio_update_packet_stats(&txvq->stats, txm);
1084         }
1085
1086         txvq->stats.packets += nb_tx;
1087
1088         if (likely(nb_tx)) {
1089                 vq_update_avail_idx(vq);
1090
1091                 if (unlikely(virtqueue_kick_prepare(vq))) {
1092                         virtqueue_notify(vq);
1093                         PMD_TX_LOG(DEBUG, "Notified backend after xmit");
1094                 }
1095         }
1096
1097         return nb_tx;
1098 }