1 /* SPDX-License-Identifier: BSD-3-Clause 2 * Copyright(c) 2010-2017 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_vhost.h> 12 13 #include "main.h" 14 15 /* 16 * A very simple vhost-user net driver implementation, without 17 * any extra features being enabled, such as TSO and mrg-Rx. 18 */ 19 20 void 21 vs_vhost_net_setup(struct vhost_dev *dev) 22 { 23 uint16_t i; 24 int vid = dev->vid; 25 struct vhost_queue *queue; 26 27 RTE_LOG(INFO, VHOST_CONFIG, 28 "setting builtin vhost-user net driver\n"); 29 30 rte_vhost_get_negotiated_features(vid, &dev->features); 31 if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF)) 32 dev->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); 33 else 34 dev->hdr_len = sizeof(struct virtio_net_hdr); 35 36 rte_vhost_get_mem_table(vid, &dev->mem); 37 38 dev->nr_vrings = rte_vhost_get_vring_num(vid); 39 for (i = 0; i < dev->nr_vrings; i++) { 40 queue = &dev->queues[i]; 41 42 queue->last_used_idx = 0; 43 queue->last_avail_idx = 0; 44 rte_vhost_get_vhost_vring(vid, i, &queue->vr); 45 } 46 } 47 48 void 49 vs_vhost_net_remove(struct vhost_dev *dev) 50 { 51 free(dev->mem); 52 } 53 54 static __rte_always_inline int 55 enqueue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr, 56 struct rte_mbuf *m, uint16_t desc_idx) 57 { 58 uint32_t desc_avail, desc_offset; 59 uint32_t mbuf_avail, mbuf_offset; 60 uint32_t cpy_len; 61 struct vring_desc *desc; 62 uint64_t desc_addr; 63 struct virtio_net_hdr virtio_hdr = {0, 0, 0, 0, 0, 0}; 64 /* A counter to avoid desc dead loop chain */ 65 uint16_t nr_desc = 1; 66 67 desc = &vr->desc[desc_idx]; 68 desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr); 69 /* 70 * Checking of 'desc_addr' placed outside of 'unlikely' macro to avoid 71 * performance issue with some versions of gcc (4.8.4 and 5.3.0) which 72 * otherwise stores offset on the stack instead of in a register. 73 */ 74 if (unlikely(desc->len < dev->hdr_len) || !desc_addr) 75 return -1; 76 77 rte_prefetch0((void *)(uintptr_t)desc_addr); 78 79 /* write virtio-net header */ 80 *(struct virtio_net_hdr *)(uintptr_t)desc_addr = virtio_hdr; 81 82 desc_offset = dev->hdr_len; 83 desc_avail = desc->len - dev->hdr_len; 84 85 mbuf_avail = rte_pktmbuf_data_len(m); 86 mbuf_offset = 0; 87 while (mbuf_avail != 0 || m->next != NULL) { 88 /* done with current mbuf, fetch next */ 89 if (mbuf_avail == 0) { 90 m = m->next; 91 92 mbuf_offset = 0; 93 mbuf_avail = rte_pktmbuf_data_len(m); 94 } 95 96 /* done with current desc buf, fetch next */ 97 if (desc_avail == 0) { 98 if ((desc->flags & VRING_DESC_F_NEXT) == 0) { 99 /* Room in vring buffer is not enough */ 100 return -1; 101 } 102 if (unlikely(desc->next >= vr->size || 103 ++nr_desc > vr->size)) 104 return -1; 105 106 desc = &vr->desc[desc->next]; 107 desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr); 108 if (unlikely(!desc_addr)) 109 return -1; 110 111 desc_offset = 0; 112 desc_avail = desc->len; 113 } 114 115 cpy_len = RTE_MIN(desc_avail, mbuf_avail); 116 rte_memcpy((void *)((uintptr_t)(desc_addr + desc_offset)), 117 rte_pktmbuf_mtod_offset(m, void *, mbuf_offset), 118 cpy_len); 119 120 mbuf_avail -= cpy_len; 121 mbuf_offset += cpy_len; 122 desc_avail -= cpy_len; 123 desc_offset += cpy_len; 124 } 125 126 return 0; 127 } 128 129 uint16_t 130 vs_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id, 131 struct rte_mbuf **pkts, uint32_t count) 132 { 133 struct vhost_queue *queue; 134 struct rte_vhost_vring *vr; 135 uint16_t avail_idx, free_entries, start_idx; 136 uint16_t desc_indexes[MAX_PKT_BURST]; 137 uint16_t used_idx; 138 uint32_t i; 139 140 queue = &dev->queues[queue_id]; 141 vr = &queue->vr; 142 143 avail_idx = *((volatile uint16_t *)&vr->avail->idx); 144 start_idx = queue->last_used_idx; 145 free_entries = avail_idx - start_idx; 146 count = RTE_MIN(count, free_entries); 147 count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST); 148 if (count == 0) 149 return 0; 150 151 /* Retrieve all of the desc indexes first to avoid caching issues. */ 152 rte_prefetch0(&vr->avail->ring[start_idx & (vr->size - 1)]); 153 for (i = 0; i < count; i++) { 154 used_idx = (start_idx + i) & (vr->size - 1); 155 desc_indexes[i] = vr->avail->ring[used_idx]; 156 vr->used->ring[used_idx].id = desc_indexes[i]; 157 vr->used->ring[used_idx].len = pkts[i]->pkt_len + 158 dev->hdr_len; 159 } 160 161 rte_prefetch0(&vr->desc[desc_indexes[0]]); 162 for (i = 0; i < count; i++) { 163 uint16_t desc_idx = desc_indexes[i]; 164 int err; 165 166 err = enqueue_pkt(dev, vr, pkts[i], desc_idx); 167 if (unlikely(err)) { 168 used_idx = (start_idx + i) & (vr->size - 1); 169 vr->used->ring[used_idx].len = dev->hdr_len; 170 } 171 172 if (i + 1 < count) 173 rte_prefetch0(&vr->desc[desc_indexes[i+1]]); 174 } 175 176 rte_smp_wmb(); 177 178 *(volatile uint16_t *)&vr->used->idx += count; 179 queue->last_used_idx += count; 180 181 rte_vhost_vring_call(dev->vid, queue_id); 182 183 return count; 184 } 185 186 static __rte_always_inline int 187 dequeue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr, 188 struct rte_mbuf *m, uint16_t desc_idx, 189 struct rte_mempool *mbuf_pool) 190 { 191 struct vring_desc *desc; 192 uint64_t desc_addr; 193 uint32_t desc_avail, desc_offset; 194 uint32_t mbuf_avail, mbuf_offset; 195 uint32_t cpy_len; 196 struct rte_mbuf *cur = m, *prev = m; 197 /* A counter to avoid desc dead loop chain */ 198 uint32_t nr_desc = 1; 199 200 desc = &vr->desc[desc_idx]; 201 if (unlikely((desc->len < dev->hdr_len)) || 202 (desc->flags & VRING_DESC_F_INDIRECT)) 203 return -1; 204 205 desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr); 206 if (unlikely(!desc_addr)) 207 return -1; 208 209 /* 210 * We don't support ANY_LAYOUT, neither VERSION_1, meaning 211 * a Tx packet from guest must have 2 desc buffers at least: 212 * the first for storing the header and the others for 213 * storing the data. 214 * 215 * And since we don't support TSO, we could simply skip the 216 * header. 217 */ 218 desc = &vr->desc[desc->next]; 219 desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr); 220 if (unlikely(!desc_addr)) 221 return -1; 222 rte_prefetch0((void *)(uintptr_t)desc_addr); 223 224 desc_offset = 0; 225 desc_avail = desc->len; 226 nr_desc += 1; 227 228 mbuf_offset = 0; 229 mbuf_avail = m->buf_len - RTE_PKTMBUF_HEADROOM; 230 while (1) { 231 cpy_len = RTE_MIN(desc_avail, mbuf_avail); 232 rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *, 233 mbuf_offset), 234 (void *)((uintptr_t)(desc_addr + desc_offset)), 235 cpy_len); 236 237 mbuf_avail -= cpy_len; 238 mbuf_offset += cpy_len; 239 desc_avail -= cpy_len; 240 desc_offset += cpy_len; 241 242 /* This desc reaches to its end, get the next one */ 243 if (desc_avail == 0) { 244 if ((desc->flags & VRING_DESC_F_NEXT) == 0) 245 break; 246 247 if (unlikely(desc->next >= vr->size || 248 ++nr_desc > vr->size)) 249 return -1; 250 desc = &vr->desc[desc->next]; 251 252 desc_addr = rte_vhost_gpa_to_vva(dev->mem, desc->addr); 253 if (unlikely(!desc_addr)) 254 return -1; 255 rte_prefetch0((void *)(uintptr_t)desc_addr); 256 257 desc_offset = 0; 258 desc_avail = desc->len; 259 } 260 261 /* 262 * This mbuf reaches to its end, get a new one 263 * to hold more data. 264 */ 265 if (mbuf_avail == 0) { 266 cur = rte_pktmbuf_alloc(mbuf_pool); 267 if (unlikely(cur == NULL)) { 268 RTE_LOG(ERR, VHOST_DATA, "Failed to " 269 "allocate memory for mbuf.\n"); 270 return -1; 271 } 272 273 prev->next = cur; 274 prev->data_len = mbuf_offset; 275 m->nb_segs += 1; 276 m->pkt_len += mbuf_offset; 277 prev = cur; 278 279 mbuf_offset = 0; 280 mbuf_avail = cur->buf_len - RTE_PKTMBUF_HEADROOM; 281 } 282 } 283 284 prev->data_len = mbuf_offset; 285 m->pkt_len += mbuf_offset; 286 287 return 0; 288 } 289 290 uint16_t 291 vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id, 292 struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count) 293 { 294 struct vhost_queue *queue; 295 struct rte_vhost_vring *vr; 296 uint32_t desc_indexes[MAX_PKT_BURST]; 297 uint32_t used_idx; 298 uint32_t i = 0; 299 uint16_t free_entries; 300 uint16_t avail_idx; 301 302 queue = &dev->queues[queue_id]; 303 vr = &queue->vr; 304 305 free_entries = *((volatile uint16_t *)&vr->avail->idx) - 306 queue->last_avail_idx; 307 if (free_entries == 0) 308 return 0; 309 310 /* Prefetch available and used ring */ 311 avail_idx = queue->last_avail_idx & (vr->size - 1); 312 used_idx = queue->last_used_idx & (vr->size - 1); 313 rte_prefetch0(&vr->avail->ring[avail_idx]); 314 rte_prefetch0(&vr->used->ring[used_idx]); 315 316 count = RTE_MIN(count, MAX_PKT_BURST); 317 count = RTE_MIN(count, free_entries); 318 319 if (unlikely(count == 0)) 320 return 0; 321 322 /* 323 * Retrieve all of the head indexes first and pre-update used entries 324 * to avoid caching issues. 325 */ 326 for (i = 0; i < count; i++) { 327 avail_idx = (queue->last_avail_idx + i) & (vr->size - 1); 328 used_idx = (queue->last_used_idx + i) & (vr->size - 1); 329 desc_indexes[i] = vr->avail->ring[avail_idx]; 330 331 vr->used->ring[used_idx].id = desc_indexes[i]; 332 vr->used->ring[used_idx].len = 0; 333 } 334 335 /* Prefetch descriptor index. */ 336 rte_prefetch0(&vr->desc[desc_indexes[0]]); 337 for (i = 0; i < count; i++) { 338 int err; 339 340 if (likely(i + 1 < count)) 341 rte_prefetch0(&vr->desc[desc_indexes[i + 1]]); 342 343 pkts[i] = rte_pktmbuf_alloc(mbuf_pool); 344 if (unlikely(pkts[i] == NULL)) { 345 RTE_LOG(ERR, VHOST_DATA, 346 "Failed to allocate memory for mbuf.\n"); 347 break; 348 } 349 350 err = dequeue_pkt(dev, vr, pkts[i], desc_indexes[i], mbuf_pool); 351 if (unlikely(err)) { 352 rte_pktmbuf_free(pkts[i]); 353 break; 354 } 355 356 } 357 358 queue->last_avail_idx += i; 359 queue->last_used_idx += i; 360 rte_smp_wmb(); 361 rte_smp_rmb(); 362 363 vr->used->idx += i; 364 365 rte_vhost_vring_call(dev->vid, queue_id); 366 367 return i; 368 } 369