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 <stdlib.h> 8 #include <linux/virtio_net.h> 9 10 #include <rte_mbuf.h> 11 #include <rte_memcpy.h> 12 #include <rte_vhost.h> 13 14 #include "main.h" 15 16 /* 17 * A very simple vhost-user net driver implementation, without 18 * any extra features being enabled, such as TSO and mrg-Rx. 19 */ 20 21 void 22 vs_vhost_net_setup(struct vhost_dev *dev) 23 { 24 uint16_t i; 25 int vid = dev->vid; 26 struct vhost_queue *queue; 27 int ret; 28 29 RTE_LOG(INFO, VHOST_CONFIG, 30 "setting builtin vhost-user net driver\n"); 31 32 rte_vhost_get_negotiated_features(vid, &dev->features); 33 if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF)) 34 dev->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); 35 else 36 dev->hdr_len = sizeof(struct virtio_net_hdr); 37 38 ret = rte_vhost_get_mem_table(vid, &dev->mem); 39 if (ret < 0) { 40 RTE_LOG(ERR, VHOST_CONFIG, "Failed to get " 41 "VM memory layout for device(%d)\n", vid); 42 return; 43 } 44 45 dev->nr_vrings = rte_vhost_get_vring_num(vid); 46 for (i = 0; i < dev->nr_vrings; i++) { 47 queue = &dev->queues[i]; 48 49 queue->last_used_idx = 0; 50 queue->last_avail_idx = 0; 51 rte_vhost_get_vhost_vring(vid, i, &queue->vr); 52 } 53 } 54 55 void 56 vs_vhost_net_remove(struct vhost_dev *dev) 57 { 58 free(dev->mem); 59 } 60 61 static __rte_always_inline int 62 enqueue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr, 63 struct rte_mbuf *m, uint16_t desc_idx) 64 { 65 uint32_t desc_avail, desc_offset; 66 uint64_t desc_chunck_len; 67 uint32_t mbuf_avail, mbuf_offset; 68 uint32_t cpy_len; 69 struct vring_desc *desc; 70 uint64_t desc_addr, desc_gaddr; 71 struct virtio_net_hdr virtio_hdr = {0, 0, 0, 0, 0, 0}; 72 /* A counter to avoid desc dead loop chain */ 73 uint16_t nr_desc = 1; 74 75 desc = &vr->desc[desc_idx]; 76 desc_chunck_len = desc->len; 77 desc_gaddr = desc->addr; 78 desc_addr = rte_vhost_va_from_guest_pa( 79 dev->mem, desc_gaddr, &desc_chunck_len); 80 /* 81 * Checking of 'desc_addr' placed outside of 'unlikely' macro to avoid 82 * performance issue with some versions of gcc (4.8.4 and 5.3.0) which 83 * otherwise stores offset on the stack instead of in a register. 84 */ 85 if (unlikely(desc->len < dev->hdr_len) || !desc_addr) 86 return -1; 87 88 rte_prefetch0((void *)(uintptr_t)desc_addr); 89 90 /* write virtio-net header */ 91 if (likely(desc_chunck_len >= dev->hdr_len)) { 92 *(struct virtio_net_hdr *)(uintptr_t)desc_addr = virtio_hdr; 93 desc_offset = dev->hdr_len; 94 } else { 95 uint64_t len; 96 uint64_t remain = dev->hdr_len; 97 uint64_t src = (uint64_t)(uintptr_t)&virtio_hdr, dst; 98 uint64_t guest_addr = desc_gaddr; 99 100 while (remain) { 101 len = remain; 102 dst = rte_vhost_va_from_guest_pa(dev->mem, 103 guest_addr, &len); 104 if (unlikely(!dst || !len)) 105 return -1; 106 107 rte_memcpy((void *)(uintptr_t)dst, 108 (void *)(uintptr_t)src, 109 len); 110 111 remain -= len; 112 guest_addr += len; 113 src += len; 114 } 115 116 desc_chunck_len = desc->len - dev->hdr_len; 117 desc_gaddr += dev->hdr_len; 118 desc_addr = rte_vhost_va_from_guest_pa( 119 dev->mem, desc_gaddr, 120 &desc_chunck_len); 121 if (unlikely(!desc_addr)) 122 return -1; 123 124 desc_offset = 0; 125 } 126 127 desc_avail = desc->len - dev->hdr_len; 128 129 mbuf_avail = rte_pktmbuf_data_len(m); 130 mbuf_offset = 0; 131 while (mbuf_avail != 0 || m->next != NULL) { 132 /* done with current mbuf, fetch next */ 133 if (mbuf_avail == 0) { 134 m = m->next; 135 136 mbuf_offset = 0; 137 mbuf_avail = rte_pktmbuf_data_len(m); 138 } 139 140 /* done with current desc buf, fetch next */ 141 if (desc_avail == 0) { 142 if ((desc->flags & VRING_DESC_F_NEXT) == 0) { 143 /* Room in vring buffer is not enough */ 144 return -1; 145 } 146 if (unlikely(desc->next >= vr->size || 147 ++nr_desc > vr->size)) 148 return -1; 149 150 desc = &vr->desc[desc->next]; 151 desc_chunck_len = desc->len; 152 desc_gaddr = desc->addr; 153 desc_addr = rte_vhost_va_from_guest_pa( 154 dev->mem, desc_gaddr, &desc_chunck_len); 155 if (unlikely(!desc_addr)) 156 return -1; 157 158 desc_offset = 0; 159 desc_avail = desc->len; 160 } else if (unlikely(desc_chunck_len == 0)) { 161 desc_chunck_len = desc_avail; 162 desc_gaddr += desc_offset; 163 desc_addr = rte_vhost_va_from_guest_pa(dev->mem, 164 desc_gaddr, 165 &desc_chunck_len); 166 if (unlikely(!desc_addr)) 167 return -1; 168 169 desc_offset = 0; 170 } 171 172 cpy_len = RTE_MIN(desc_chunck_len, mbuf_avail); 173 rte_memcpy((void *)((uintptr_t)(desc_addr + desc_offset)), 174 rte_pktmbuf_mtod_offset(m, void *, mbuf_offset), 175 cpy_len); 176 177 mbuf_avail -= cpy_len; 178 mbuf_offset += cpy_len; 179 desc_avail -= cpy_len; 180 desc_offset += cpy_len; 181 desc_chunck_len -= cpy_len; 182 } 183 184 return 0; 185 } 186 187 uint16_t 188 vs_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id, 189 struct rte_mbuf **pkts, uint32_t count) 190 { 191 struct vhost_queue *queue; 192 struct rte_vhost_vring *vr; 193 uint16_t avail_idx, free_entries, start_idx; 194 uint16_t desc_indexes[MAX_PKT_BURST]; 195 uint16_t used_idx; 196 uint32_t i; 197 198 queue = &dev->queues[queue_id]; 199 vr = &queue->vr; 200 201 avail_idx = rte_atomic_load_explicit((uint16_t __rte_atomic *)&vr->avail->idx, 202 rte_memory_order_acquire); 203 start_idx = queue->last_used_idx; 204 free_entries = avail_idx - start_idx; 205 count = RTE_MIN(count, free_entries); 206 count = RTE_MIN(count, (uint32_t)MAX_PKT_BURST); 207 if (count == 0) 208 return 0; 209 210 /* Retrieve all of the desc indexes first to avoid caching issues. */ 211 rte_prefetch0(&vr->avail->ring[start_idx & (vr->size - 1)]); 212 for (i = 0; i < count; i++) { 213 used_idx = (start_idx + i) & (vr->size - 1); 214 desc_indexes[i] = vr->avail->ring[used_idx]; 215 vr->used->ring[used_idx].id = desc_indexes[i]; 216 vr->used->ring[used_idx].len = pkts[i]->pkt_len + 217 dev->hdr_len; 218 } 219 220 rte_prefetch0(&vr->desc[desc_indexes[0]]); 221 for (i = 0; i < count; i++) { 222 uint16_t desc_idx = desc_indexes[i]; 223 int err; 224 225 err = enqueue_pkt(dev, vr, pkts[i], desc_idx); 226 if (unlikely(err)) { 227 used_idx = (start_idx + i) & (vr->size - 1); 228 vr->used->ring[used_idx].len = dev->hdr_len; 229 } 230 231 if (i + 1 < count) 232 rte_prefetch0(&vr->desc[desc_indexes[i+1]]); 233 } 234 235 rte_atomic_fetch_add_explicit((uint16_t __rte_atomic *)&vr->used->idx, count, 236 rte_memory_order_release); 237 queue->last_used_idx += count; 238 239 rte_vhost_vring_call(dev->vid, queue_id); 240 241 return count; 242 } 243 244 uint16_t 245 builtin_enqueue_pkts(struct vhost_dev *dev, uint16_t queue_id, 246 struct rte_mbuf **pkts, uint32_t count) 247 { 248 return vs_enqueue_pkts(dev, queue_id, pkts, count); 249 } 250 251 static __rte_always_inline int 252 dequeue_pkt(struct vhost_dev *dev, struct rte_vhost_vring *vr, 253 struct rte_mbuf *m, uint16_t desc_idx, 254 struct rte_mempool *mbuf_pool) 255 { 256 struct vring_desc *desc; 257 uint64_t desc_addr, desc_gaddr; 258 uint32_t desc_avail, desc_offset; 259 uint64_t desc_chunck_len; 260 uint32_t mbuf_avail, mbuf_offset; 261 uint32_t cpy_len; 262 struct rte_mbuf *cur = m, *prev = m; 263 /* A counter to avoid desc dead loop chain */ 264 uint32_t nr_desc = 1; 265 266 desc = &vr->desc[desc_idx]; 267 if (unlikely((desc->len < dev->hdr_len)) || 268 (desc->flags & VRING_DESC_F_INDIRECT)) 269 return -1; 270 271 desc_chunck_len = desc->len; 272 desc_gaddr = desc->addr; 273 desc_addr = rte_vhost_va_from_guest_pa( 274 dev->mem, desc_gaddr, &desc_chunck_len); 275 if (unlikely(!desc_addr)) 276 return -1; 277 278 /* 279 * We don't support ANY_LAYOUT, neither VERSION_1, meaning 280 * a Tx packet from guest must have 2 desc buffers at least: 281 * the first for storing the header and the others for 282 * storing the data. 283 * 284 * And since we don't support TSO, we could simply skip the 285 * header. 286 */ 287 desc = &vr->desc[desc->next]; 288 desc_chunck_len = desc->len; 289 desc_gaddr = desc->addr; 290 desc_addr = rte_vhost_va_from_guest_pa( 291 dev->mem, desc_gaddr, &desc_chunck_len); 292 if (unlikely(!desc_addr)) 293 return -1; 294 rte_prefetch0((void *)(uintptr_t)desc_addr); 295 296 desc_offset = 0; 297 desc_avail = desc->len; 298 nr_desc += 1; 299 300 mbuf_offset = 0; 301 mbuf_avail = m->buf_len - RTE_PKTMBUF_HEADROOM; 302 while (1) { 303 cpy_len = RTE_MIN(desc_chunck_len, mbuf_avail); 304 rte_memcpy(rte_pktmbuf_mtod_offset(cur, void *, 305 mbuf_offset), 306 (void *)((uintptr_t)(desc_addr + desc_offset)), 307 cpy_len); 308 309 mbuf_avail -= cpy_len; 310 mbuf_offset += cpy_len; 311 desc_avail -= cpy_len; 312 desc_offset += cpy_len; 313 desc_chunck_len -= cpy_len; 314 315 /* This desc reaches to its end, get the next one */ 316 if (desc_avail == 0) { 317 if ((desc->flags & VRING_DESC_F_NEXT) == 0) 318 break; 319 320 if (unlikely(desc->next >= vr->size || 321 ++nr_desc > vr->size)) 322 return -1; 323 desc = &vr->desc[desc->next]; 324 325 desc_chunck_len = desc->len; 326 desc_gaddr = desc->addr; 327 desc_addr = rte_vhost_va_from_guest_pa( 328 dev->mem, desc_gaddr, &desc_chunck_len); 329 if (unlikely(!desc_addr)) 330 return -1; 331 rte_prefetch0((void *)(uintptr_t)desc_addr); 332 333 desc_offset = 0; 334 desc_avail = desc->len; 335 } else if (unlikely(desc_chunck_len == 0)) { 336 desc_chunck_len = desc_avail; 337 desc_gaddr += desc_offset; 338 desc_addr = rte_vhost_va_from_guest_pa(dev->mem, 339 desc_gaddr, 340 &desc_chunck_len); 341 if (unlikely(!desc_addr)) 342 return -1; 343 344 desc_offset = 0; 345 } 346 347 /* 348 * This mbuf reaches to its end, get a new one 349 * to hold more data. 350 */ 351 if (mbuf_avail == 0) { 352 cur = rte_pktmbuf_alloc(mbuf_pool); 353 if (unlikely(cur == NULL)) { 354 RTE_LOG(ERR, VHOST_DATA, "Failed to " 355 "allocate memory for mbuf.\n"); 356 return -1; 357 } 358 359 prev->next = cur; 360 prev->data_len = mbuf_offset; 361 m->nb_segs += 1; 362 m->pkt_len += mbuf_offset; 363 prev = cur; 364 365 mbuf_offset = 0; 366 mbuf_avail = cur->buf_len - RTE_PKTMBUF_HEADROOM; 367 } 368 } 369 370 prev->data_len = mbuf_offset; 371 m->pkt_len += mbuf_offset; 372 373 return 0; 374 } 375 376 static uint16_t 377 vs_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id, 378 struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count) 379 { 380 struct vhost_queue *queue; 381 struct rte_vhost_vring *vr; 382 uint32_t desc_indexes[MAX_PKT_BURST]; 383 uint32_t used_idx; 384 uint32_t i = 0; 385 uint16_t free_entries; 386 uint16_t avail_idx; 387 388 queue = &dev->queues[queue_id]; 389 vr = &queue->vr; 390 391 free_entries = rte_atomic_load_explicit((uint16_t __rte_atomic *)&vr->avail->idx, 392 rte_memory_order_acquire) - queue->last_avail_idx; 393 if (free_entries == 0) 394 return 0; 395 396 /* Prefetch available and used ring */ 397 avail_idx = queue->last_avail_idx & (vr->size - 1); 398 used_idx = queue->last_used_idx & (vr->size - 1); 399 rte_prefetch0(&vr->avail->ring[avail_idx]); 400 rte_prefetch0(&vr->used->ring[used_idx]); 401 402 count = RTE_MIN(count, MAX_PKT_BURST); 403 count = RTE_MIN(count, free_entries); 404 405 if (unlikely(count == 0)) 406 return 0; 407 408 /* 409 * Retrieve all of the head indexes first and pre-update used entries 410 * to avoid caching issues. 411 */ 412 for (i = 0; i < count; i++) { 413 avail_idx = (queue->last_avail_idx + i) & (vr->size - 1); 414 used_idx = (queue->last_used_idx + i) & (vr->size - 1); 415 desc_indexes[i] = vr->avail->ring[avail_idx]; 416 417 vr->used->ring[used_idx].id = desc_indexes[i]; 418 vr->used->ring[used_idx].len = 0; 419 } 420 421 /* Prefetch descriptor index. */ 422 rte_prefetch0(&vr->desc[desc_indexes[0]]); 423 for (i = 0; i < count; i++) { 424 int err; 425 426 if (likely(i + 1 < count)) 427 rte_prefetch0(&vr->desc[desc_indexes[i + 1]]); 428 429 pkts[i] = rte_pktmbuf_alloc(mbuf_pool); 430 if (unlikely(pkts[i] == NULL)) { 431 RTE_LOG(ERR, VHOST_DATA, 432 "Failed to allocate memory for mbuf.\n"); 433 break; 434 } 435 436 err = dequeue_pkt(dev, vr, pkts[i], desc_indexes[i], mbuf_pool); 437 if (unlikely(err)) { 438 rte_pktmbuf_free(pkts[i]); 439 break; 440 } 441 442 } 443 444 queue->last_avail_idx += i; 445 queue->last_used_idx += i; 446 447 rte_atomic_fetch_add_explicit((uint16_t __rte_atomic *)&vr->used->idx, i, 448 rte_memory_order_acq_rel); 449 450 rte_vhost_vring_call(dev->vid, queue_id); 451 452 return i; 453 } 454 455 uint16_t 456 builtin_dequeue_pkts(struct vhost_dev *dev, uint16_t queue_id, 457 struct rte_mempool *mbuf_pool, struct rte_mbuf **pkts, uint16_t count) 458 { 459 return vs_dequeue_pkts(dev, queue_id, mbuf_pool, pkts, count); 460 } 461