drivers/net/virtio/virtqueue.h

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2014 Intel Corporation
   3  */
   4
   5 #ifndef _VIRTQUEUE_H_
   6 #define _VIRTQUEUE_H_
   7
   8 #include <stdint.h>
   9
  10 #include <rte_atomic.h>
  11 #include <rte_memory.h>
  12 #include <rte_mempool.h>
  13 #include <rte_net.h>
  14
  15 #include "virtio.h"
  16 #include "virtio_ring.h"
  17 #include "virtio_logs.h"
  18 #include "virtio_rxtx.h"
  19
  20 struct rte_mbuf;
  21
  22 #define DEFAULT_TX_FREE_THRESH 32
  23 #define DEFAULT_RX_FREE_THRESH 32
  24
  25 #define VIRTIO_MBUF_BURST_SZ 64
  26 /*
  27  * Per virtio_ring.h in Linux.
  28  *     For virtio_pci on SMP, we don't need to order with respect to MMIO
  29  *     accesses through relaxed memory I/O windows, so thread_fence is
  30  *     sufficient.
  31  *
  32  *     For using virtio to talk to real devices (eg. vDPA) we do need real
  33  *     barriers.
  34  */
  35 static inline void
  36 virtio_mb(uint8_t weak_barriers)
  37 {
  38         if (weak_barriers)
  39                 rte_atomic_thread_fence(__ATOMIC_SEQ_CST);
  40         else
  41                 rte_mb();
  42 }
  43
  44 static inline void
  45 virtio_rmb(uint8_t weak_barriers)
  46 {
  47         if (weak_barriers)
  48                 rte_atomic_thread_fence(__ATOMIC_ACQUIRE);
  49         else
  50                 rte_io_rmb();
  51 }
  52
  53 static inline void
  54 virtio_wmb(uint8_t weak_barriers)
  55 {
  56         if (weak_barriers)
  57                 rte_atomic_thread_fence(__ATOMIC_RELEASE);
  58         else
  59                 rte_io_wmb();
  60 }
  61
  62 static inline uint16_t
  63 virtqueue_fetch_flags_packed(struct vring_packed_desc *dp,
  64                               uint8_t weak_barriers)
  65 {
  66         uint16_t flags;
  67
  68         if (weak_barriers) {
  69 /* x86 prefers to using rte_io_rmb over __atomic_load_n as it reports
  70  * a better perf(~1.5%), which comes from the saved branch by the compiler.
  71  * The if and else branch are identical  on the platforms except Arm.
  72  */
  73 #ifdef RTE_ARCH_ARM
  74                 flags = __atomic_load_n(&dp->flags, __ATOMIC_ACQUIRE);
  75 #else
  76                 flags = dp->flags;
  77                 rte_io_rmb();
  78 #endif
  79         } else {
  80                 flags = dp->flags;
  81                 rte_io_rmb();
  82         }
  83
  84         return flags;
  85 }
  86
  87 static inline void
  88 virtqueue_store_flags_packed(struct vring_packed_desc *dp,
  89                               uint16_t flags, uint8_t weak_barriers)
  90 {
  91         if (weak_barriers) {
  92 /* x86 prefers to using rte_io_wmb over __atomic_store_n as it reports
  93  * a better perf(~1.5%), which comes from the saved branch by the compiler.
  94  * The if and else branch are identical on the platforms except Arm.
  95  */
  96 #ifdef RTE_ARCH_ARM
  97                 __atomic_store_n(&dp->flags, flags, __ATOMIC_RELEASE);
  98 #else
  99                 rte_io_wmb();
 100                 dp->flags = flags;
 101 #endif
 102         } else {
 103                 rte_io_wmb();
 104                 dp->flags = flags;
 105         }
 106 }
 107
 108 #ifdef RTE_PMD_PACKET_PREFETCH
 109 #define rte_packet_prefetch(p)  rte_prefetch1(p)
 110 #else
 111 #define rte_packet_prefetch(p)  do {} while(0)
 112 #endif
 113
 114 #define VIRTQUEUE_MAX_NAME_SZ 32
 115
 116 #define VTNET_SQ_RQ_QUEUE_IDX 0
 117 #define VTNET_SQ_TQ_QUEUE_IDX 1
 118 #define VTNET_SQ_CQ_QUEUE_IDX 2
 119
 120 enum { VTNET_RQ = 0, VTNET_TQ = 1, VTNET_CQ = 2 };
 121 /**
 122  * The maximum virtqueue size is 2^15. Use that value as the end of
 123  * descriptor chain terminator since it will never be a valid index
 124  * in the descriptor table. This is used to verify we are correctly
 125  * handling vq_free_cnt.
 126  */
 127 #define VQ_RING_DESC_CHAIN_END 32768
 128
 129 /**
 130  * Control the RX mode, ie. promiscuous, allmulti, etc...
 131  * All commands require an "out" sg entry containing a 1 byte
 132  * state value, zero = disable, non-zero = enable.  Commands
 133  * 0 and 1 are supported with the VIRTIO_NET_F_CTRL_RX feature.
 134  * Commands 2-5 are added with VIRTIO_NET_F_CTRL_RX_EXTRA.
 135  */
 136 #define VIRTIO_NET_CTRL_RX              0
 137 #define VIRTIO_NET_CTRL_RX_PROMISC      0
 138 #define VIRTIO_NET_CTRL_RX_ALLMULTI     1
 139 #define VIRTIO_NET_CTRL_RX_ALLUNI       2
 140 #define VIRTIO_NET_CTRL_RX_NOMULTI      3
 141 #define VIRTIO_NET_CTRL_RX_NOUNI        4
 142 #define VIRTIO_NET_CTRL_RX_NOBCAST      5
 143
 144 /**
 145  * Control the MAC
 146  *
 147  * The MAC filter table is managed by the hypervisor, the guest should
 148  * assume the size is infinite.  Filtering should be considered
 149  * non-perfect, ie. based on hypervisor resources, the guest may
 150  * received packets from sources not specified in the filter list.
 151  *
 152  * In addition to the class/cmd header, the TABLE_SET command requires
 153  * two out scatterlists.  Each contains a 4 byte count of entries followed
 154  * by a concatenated byte stream of the ETH_ALEN MAC addresses.  The
 155  * first sg list contains unicast addresses, the second is for multicast.
 156  * This functionality is present if the VIRTIO_NET_F_CTRL_RX feature
 157  * is available.
 158  *
 159  * The ADDR_SET command requests one out scatterlist, it contains a
 160  * 6 bytes MAC address. This functionality is present if the
 161  * VIRTIO_NET_F_CTRL_MAC_ADDR feature is available.
 162  */
 163 struct virtio_net_ctrl_mac {
 164         uint32_t entries;
 165         uint8_t macs[][RTE_ETHER_ADDR_LEN];
 166 } __rte_packed;
 167
 168 #define VIRTIO_NET_CTRL_MAC    1
 169 #define VIRTIO_NET_CTRL_MAC_TABLE_SET        0
 170 #define VIRTIO_NET_CTRL_MAC_ADDR_SET         1
 171
 172 /**
 173  * Control VLAN filtering
 174  *
 175  * The VLAN filter table is controlled via a simple ADD/DEL interface.
 176  * VLAN IDs not added may be filtered by the hypervisor.  Del is the
 177  * opposite of add.  Both commands expect an out entry containing a 2
 178  * byte VLAN ID.  VLAN filtering is available with the
 179  * VIRTIO_NET_F_CTRL_VLAN feature bit.
 180  */
 181 #define VIRTIO_NET_CTRL_VLAN     2
 182 #define VIRTIO_NET_CTRL_VLAN_ADD 0
 183 #define VIRTIO_NET_CTRL_VLAN_DEL 1
 184
 185 /*
 186  * Control link announce acknowledgement
 187  *
 188  * The command VIRTIO_NET_CTRL_ANNOUNCE_ACK is used to indicate that
 189  * driver has recevied the notification; device would clear the
 190  * VIRTIO_NET_S_ANNOUNCE bit in the status field after it receives
 191  * this command.
 192  */
 193 #define VIRTIO_NET_CTRL_ANNOUNCE     3
 194 #define VIRTIO_NET_CTRL_ANNOUNCE_ACK 0
 195
 196 struct virtio_net_ctrl_hdr {
 197         uint8_t class;
 198         uint8_t cmd;
 199 } __rte_packed;
 200
 201 typedef uint8_t virtio_net_ctrl_ack;
 202
 203 #define VIRTIO_NET_OK     0
 204 #define VIRTIO_NET_ERR    1
 205
 206 #define VIRTIO_MAX_CTRL_DATA 2048
 207
 208 struct virtio_pmd_ctrl {
 209         struct virtio_net_ctrl_hdr hdr;
 210         virtio_net_ctrl_ack status;
 211         uint8_t data[VIRTIO_MAX_CTRL_DATA];
 212 };
 213
 214 struct vq_desc_extra {
 215         void *cookie;
 216         uint16_t ndescs;
 217         uint16_t next;
 218 };
 219
 220 struct virtqueue {
 221         struct virtio_hw  *hw; /**< virtio_hw structure pointer. */
 222         union {
 223                 struct {
 224                         /**< vring keeping desc, used and avail */
 225                         struct vring ring;
 226                 } vq_split;
 227
 228                 struct {
 229                         /**< vring keeping descs and events */
 230                         struct vring_packed ring;
 231                         bool used_wrap_counter;
 232                         uint16_t cached_flags; /**< cached flags for descs */
 233                         uint16_t event_flags_shadow;
 234                 } vq_packed;
 235         };
 236
 237         uint16_t vq_used_cons_idx; /**< last consumed descriptor */
 238         uint16_t vq_nentries;  /**< vring desc numbers */
 239         uint16_t vq_free_cnt;  /**< num of desc available */
 240         uint16_t vq_avail_idx; /**< sync until needed */
 241         uint16_t vq_free_thresh; /**< free threshold */
 242
 243         void *vq_ring_virt_mem;  /**< linear address of vring*/
 244         unsigned int vq_ring_size;
 245
 246         union {
 247                 struct virtnet_rx rxq;
 248                 struct virtnet_tx txq;
 249                 struct virtnet_ctl cq;
 250         };
 251
 252         rte_iova_t vq_ring_mem; /**< physical address of vring,
 253                                  * or virtual address for virtio_user. */
 254
 255         /**
 256          * Head of the free chain in the descriptor table. If
 257          * there are no free descriptors, this will be set to
 258          * VQ_RING_DESC_CHAIN_END.
 259          */
 260         uint16_t  vq_desc_head_idx;
 261         uint16_t  vq_desc_tail_idx;
 262         uint16_t  vq_queue_index;   /**< PCI queue index */
 263         uint16_t offset; /**< relative offset to obtain addr in mbuf */
 264         uint16_t  *notify_addr;
 265         struct rte_mbuf **sw_ring;  /**< RX software ring. */
 266         struct vq_desc_extra vq_descx[0];
 267 };
 268
 269 /* If multiqueue is provided by host, then we suppport it. */
 270 #define VIRTIO_NET_CTRL_MQ   4
 271 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET        0
 272 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN        1
 273 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX        0x8000
 274
 275 /**
 276  * This is the first element of the scatter-gather list.  If you don't
 277  * specify GSO or CSUM features, you can simply ignore the header.
 278  */
 279 struct virtio_net_hdr {
 280 #define VIRTIO_NET_HDR_F_NEEDS_CSUM 1    /**< Use csum_start,csum_offset*/
 281 #define VIRTIO_NET_HDR_F_DATA_VALID 2    /**< Checksum is valid */
 282         uint8_t flags;
 283 #define VIRTIO_NET_HDR_GSO_NONE     0    /**< Not a GSO frame */
 284 #define VIRTIO_NET_HDR_GSO_TCPV4    1    /**< GSO frame, IPv4 TCP (TSO) */
 285 #define VIRTIO_NET_HDR_GSO_UDP      3    /**< GSO frame, IPv4 UDP (UFO) */
 286 #define VIRTIO_NET_HDR_GSO_TCPV6    4    /**< GSO frame, IPv6 TCP */
 287 #define VIRTIO_NET_HDR_GSO_ECN      0x80 /**< TCP has ECN set */
 288         uint8_t gso_type;
 289         uint16_t hdr_len;     /**< Ethernet + IP + tcp/udp hdrs */
 290         uint16_t gso_size;    /**< Bytes to append to hdr_len per frame */
 291         uint16_t csum_start;  /**< Position to start checksumming from */
 292         uint16_t csum_offset; /**< Offset after that to place checksum */
 293 };
 294
 295 /**
 296  * This is the version of the header to use when the MRG_RXBUF
 297  * feature has been negotiated.
 298  */
 299 struct virtio_net_hdr_mrg_rxbuf {
 300         struct   virtio_net_hdr hdr;
 301         uint16_t num_buffers; /**< Number of merged rx buffers */
 302 };
 303
 304 /* Region reserved to allow for transmit header and indirect ring */
 305 #define VIRTIO_MAX_TX_INDIRECT 8
 306 struct virtio_tx_region {
 307         struct virtio_net_hdr_mrg_rxbuf tx_hdr;
 308         union {
 309                 struct vring_desc tx_indir[VIRTIO_MAX_TX_INDIRECT];
 310                 struct vring_packed_desc
 311                         tx_packed_indir[VIRTIO_MAX_TX_INDIRECT];
 312         } __rte_aligned(16);
 313 };
 314
 315 static inline int
 316 desc_is_used(struct vring_packed_desc *desc, struct virtqueue *vq)
 317 {
 318         uint16_t used, avail, flags;
 319
 320         flags = virtqueue_fetch_flags_packed(desc, vq->hw->weak_barriers);
 321         used = !!(flags & VRING_PACKED_DESC_F_USED);
 322         avail = !!(flags & VRING_PACKED_DESC_F_AVAIL);
 323
 324         return avail == used && used == vq->vq_packed.used_wrap_counter;
 325 }
 326
 327 static inline void
 328 vring_desc_init_packed(struct virtqueue *vq, int n)
 329 {
 330         int i;
 331         for (i = 0; i < n - 1; i++) {
 332                 vq->vq_packed.ring.desc[i].id = i;
 333                 vq->vq_descx[i].next = i + 1;
 334         }
 335         vq->vq_packed.ring.desc[i].id = i;
 336         vq->vq_descx[i].next = VQ_RING_DESC_CHAIN_END;
 337 }
 338
 339 /* Chain all the descriptors in the ring with an END */
 340 static inline void
 341 vring_desc_init_split(struct vring_desc *dp, uint16_t n)
 342 {
 343         uint16_t i;
 344
 345         for (i = 0; i < n - 1; i++)
 346                 dp[i].next = (uint16_t)(i + 1);
 347         dp[i].next = VQ_RING_DESC_CHAIN_END;
 348 }
 349
 350 static inline void
 351 vring_desc_init_indirect_packed(struct vring_packed_desc *dp, int n)
 352 {
 353         int i;
 354         for (i = 0; i < n; i++) {
 355                 dp[i].id = (uint16_t)i;
 356                 dp[i].flags = VRING_DESC_F_WRITE;
 357         }
 358 }
 359
 360 /**
 361  * Tell the backend not to interrupt us. Implementation for packed virtqueues.
 362  */
 363 static inline void
 364 virtqueue_disable_intr_packed(struct virtqueue *vq)
 365 {
 366         if (vq->vq_packed.event_flags_shadow != RING_EVENT_FLAGS_DISABLE) {
 367                 vq->vq_packed.event_flags_shadow = RING_EVENT_FLAGS_DISABLE;
 368                 vq->vq_packed.ring.driver->desc_event_flags =
 369                         vq->vq_packed.event_flags_shadow;
 370         }
 371 }
 372
 373 /**
 374  * Tell the backend not to interrupt us. Implementation for split virtqueues.
 375  */
 376 static inline void
 377 virtqueue_disable_intr_split(struct virtqueue *vq)
 378 {
 379         vq->vq_split.ring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
 380 }
 381
 382 /**
 383  * Tell the backend not to interrupt us.
 384  */
 385 static inline void
 386 virtqueue_disable_intr(struct virtqueue *vq)
 387 {
 388         if (virtio_with_packed_queue(vq->hw))
 389                 virtqueue_disable_intr_packed(vq);
 390         else
 391                 virtqueue_disable_intr_split(vq);
 392 }
 393
 394 /**
 395  * Tell the backend to interrupt. Implementation for packed virtqueues.
 396  */
 397 static inline void
 398 virtqueue_enable_intr_packed(struct virtqueue *vq)
 399 {
 400         if (vq->vq_packed.event_flags_shadow == RING_EVENT_FLAGS_DISABLE) {
 401                 vq->vq_packed.event_flags_shadow = RING_EVENT_FLAGS_ENABLE;
 402                 vq->vq_packed.ring.driver->desc_event_flags =
 403                         vq->vq_packed.event_flags_shadow;
 404         }
 405 }
 406
 407 /**
 408  * Tell the backend to interrupt. Implementation for split virtqueues.
 409  */
 410 static inline void
 411 virtqueue_enable_intr_split(struct virtqueue *vq)
 412 {
 413         vq->vq_split.ring.avail->flags &= (~VRING_AVAIL_F_NO_INTERRUPT);
 414 }
 415
 416 /**
 417  * Tell the backend to interrupt us.
 418  */
 419 static inline void
 420 virtqueue_enable_intr(struct virtqueue *vq)
 421 {
 422         if (virtio_with_packed_queue(vq->hw))
 423                 virtqueue_enable_intr_packed(vq);
 424         else
 425                 virtqueue_enable_intr_split(vq);
 426 }
 427
 428 /**
 429  *  Dump virtqueue internal structures, for debug purpose only.
 430  */
 431 void virtqueue_dump(struct virtqueue *vq);
 432 /**
 433  *  Get all mbufs to be freed.
 434  */
 435 struct rte_mbuf *virtqueue_detach_unused(struct virtqueue *vq);
 436
 437 /* Flush the elements in the used ring. */
 438 void virtqueue_rxvq_flush(struct virtqueue *vq);
 439
 440 int virtqueue_rxvq_reset_packed(struct virtqueue *vq);
 441
 442 int virtqueue_txvq_reset_packed(struct virtqueue *vq);
 443
 444 static inline int
 445 virtqueue_full(const struct virtqueue *vq)
 446 {
 447         return vq->vq_free_cnt == 0;
 448 }
 449
 450 static inline int
 451 virtio_get_queue_type(struct virtio_hw *hw, uint16_t vtpci_queue_idx)
 452 {
 453         if (vtpci_queue_idx == hw->max_queue_pairs * 2)
 454                 return VTNET_CQ;
 455         else if (vtpci_queue_idx % 2 == 0)
 456                 return VTNET_RQ;
 457         else
 458                 return VTNET_TQ;
 459 }
 460
 461 /* virtqueue_nused has load-acquire or rte_io_rmb insed */
 462 static inline uint16_t
 463 virtqueue_nused(const struct virtqueue *vq)
 464 {
 465         uint16_t idx;
 466
 467         if (vq->hw->weak_barriers) {
 468         /**
 469          * x86 prefers to using rte_smp_rmb over __atomic_load_n as it
 470          * reports a slightly better perf, which comes from the saved
 471          * branch by the compiler.
 472          * The if and else branches are identical with the smp and io
 473          * barriers both defined as compiler barriers on x86.
 474          */
 475 #ifdef RTE_ARCH_X86_64
 476                 idx = vq->vq_split.ring.used->idx;
 477                 rte_smp_rmb();
 478 #else
 479                 idx = __atomic_load_n(&(vq)->vq_split.ring.used->idx,
 480                                 __ATOMIC_ACQUIRE);
 481 #endif
 482         } else {
 483                 idx = vq->vq_split.ring.used->idx;
 484                 rte_io_rmb();
 485         }
 486         return idx - vq->vq_used_cons_idx;
 487 }
 488
 489 void vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx);
 490 void vq_ring_free_chain_packed(struct virtqueue *vq, uint16_t used_idx);
 491 void vq_ring_free_inorder(struct virtqueue *vq, uint16_t desc_idx,
 492                           uint16_t num);
 493
 494 static inline void
 495 vq_update_avail_idx(struct virtqueue *vq)
 496 {
 497         if (vq->hw->weak_barriers) {
 498         /* x86 prefers to using rte_smp_wmb over __atomic_store_n as
 499          * it reports a slightly better perf, which comes from the
 500          * saved branch by the compiler.
 501          * The if and else branches are identical with the smp and
 502          * io barriers both defined as compiler barriers on x86.
 503          */
 504 #ifdef RTE_ARCH_X86_64
 505                 rte_smp_wmb();
 506                 vq->vq_split.ring.avail->idx = vq->vq_avail_idx;
 507 #else
 508                 __atomic_store_n(&vq->vq_split.ring.avail->idx,
 509                                  vq->vq_avail_idx, __ATOMIC_RELEASE);
 510 #endif
 511         } else {
 512                 rte_io_wmb();
 513                 vq->vq_split.ring.avail->idx = vq->vq_avail_idx;
 514         }
 515 }
 516
 517 static inline void
 518 vq_update_avail_ring(struct virtqueue *vq, uint16_t desc_idx)
 519 {
 520         uint16_t avail_idx;
 521         /*
 522          * Place the head of the descriptor chain into the next slot and make
 523          * it usable to the host. The chain is made available now rather than
 524          * deferring to virtqueue_notify() in the hopes that if the host is
 525          * currently running on another CPU, we can keep it processing the new
 526          * descriptor.
 527          */
 528         avail_idx = (uint16_t)(vq->vq_avail_idx & (vq->vq_nentries - 1));
 529         if (unlikely(vq->vq_split.ring.avail->ring[avail_idx] != desc_idx))
 530                 vq->vq_split.ring.avail->ring[avail_idx] = desc_idx;
 531         vq->vq_avail_idx++;
 532 }
 533
 534 static inline int
 535 virtqueue_kick_prepare(struct virtqueue *vq)
 536 {
 537         /*
 538          * Ensure updated avail->idx is visible to vhost before reading
 539          * the used->flags.
 540          */
 541         virtio_mb(vq->hw->weak_barriers);
 542         return !(vq->vq_split.ring.used->flags & VRING_USED_F_NO_NOTIFY);
 543 }
 544
 545 static inline int
 546 virtqueue_kick_prepare_packed(struct virtqueue *vq)
 547 {
 548         uint16_t flags;
 549
 550         /*
 551          * Ensure updated data is visible to vhost before reading the flags.
 552          */
 553         virtio_mb(vq->hw->weak_barriers);
 554         flags = vq->vq_packed.ring.device->desc_event_flags;
 555
 556         return flags != RING_EVENT_FLAGS_DISABLE;
 557 }
 558
 559 /*
 560  * virtqueue_kick_prepare*() or the virtio_wmb() should be called
 561  * before this function to be sure that all the data is visible to vhost.
 562  */
 563 static inline void
 564 virtqueue_notify(struct virtqueue *vq)
 565 {
 566         VIRTIO_OPS(vq->hw)->notify_queue(vq->hw, vq);
 567 }
 568
 569 #ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
 570 #define VIRTQUEUE_DUMP(vq) do { \
 571         uint16_t used_idx, nused; \
 572         used_idx = __atomic_load_n(&(vq)->vq_split.ring.used->idx, \
 573                                    __ATOMIC_RELAXED); \
 574         nused = (uint16_t)(used_idx - (vq)->vq_used_cons_idx); \
 575         if (virtio_with_packed_queue((vq)->hw)) { \
 576                 PMD_INIT_LOG(DEBUG, \
 577                 "VQ: - size=%d; free=%d; used_cons_idx=%d; avail_idx=%d;" \
 578                 " cached_flags=0x%x; used_wrap_counter=%d", \
 579                 (vq)->vq_nentries, (vq)->vq_free_cnt, (vq)->vq_used_cons_idx, \
 580                 (vq)->vq_avail_idx, (vq)->vq_packed.cached_flags, \
 581                 (vq)->vq_packed.used_wrap_counter); \
 582                 break; \
 583         } \
 584         PMD_INIT_LOG(DEBUG, \
 585           "VQ: - size=%d; free=%d; used=%d; desc_head_idx=%d;" \
 586           " avail.idx=%d; used_cons_idx=%d; used.idx=%d;" \
 587           " avail.flags=0x%x; used.flags=0x%x", \
 588           (vq)->vq_nentries, (vq)->vq_free_cnt, nused, (vq)->vq_desc_head_idx, \
 589           (vq)->vq_split.ring.avail->idx, (vq)->vq_used_cons_idx, \
 590           __atomic_load_n(&(vq)->vq_split.ring.used->idx, __ATOMIC_RELAXED), \
 591           (vq)->vq_split.ring.avail->flags, (vq)->vq_split.ring.used->flags); \
 592 } while (0)
 593 #else
 594 #define VIRTQUEUE_DUMP(vq) do { } while (0)
 595 #endif
 596
 597 /* avoid write operation when necessary, to lessen cache issues */
 598 #define ASSIGN_UNLESS_EQUAL(var, val) do {      \
 599         typeof(var) *const var_ = &(var);       \
 600         typeof(val)  const val_ = (val);        \
 601         if (*var_ != val_)                      \
 602                 *var_ = val_;                   \
 603 } while (0)
 604
 605 #define virtqueue_clear_net_hdr(hdr) do {               \
 606         typeof(hdr) hdr_ = (hdr);                       \
 607         ASSIGN_UNLESS_EQUAL((hdr_)->csum_start, 0);     \
 608         ASSIGN_UNLESS_EQUAL((hdr_)->csum_offset, 0);    \
 609         ASSIGN_UNLESS_EQUAL((hdr_)->flags, 0);          \
 610         ASSIGN_UNLESS_EQUAL((hdr_)->gso_type, 0);       \
 611         ASSIGN_UNLESS_EQUAL((hdr_)->gso_size, 0);       \
 612         ASSIGN_UNLESS_EQUAL((hdr_)->hdr_len, 0);        \
 613 } while (0)
 614
 615 static inline void
 616 virtqueue_xmit_offload(struct virtio_net_hdr *hdr,
 617                         struct rte_mbuf *cookie,
 618                         uint8_t offload)
 619 {
 620         if (offload) {
 621                 if (cookie->ol_flags & PKT_TX_TCP_SEG)
 622                         cookie->ol_flags |= PKT_TX_TCP_CKSUM;
 623
 624                 switch (cookie->ol_flags & PKT_TX_L4_MASK) {
 625                 case PKT_TX_UDP_CKSUM:
 626                         hdr->csum_start = cookie->l2_len + cookie->l3_len;
 627                         hdr->csum_offset = offsetof(struct rte_udp_hdr,
 628                                 dgram_cksum);
 629                         hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 630                         break;
 631
 632                 case PKT_TX_TCP_CKSUM:
 633                         hdr->csum_start = cookie->l2_len + cookie->l3_len;
 634                         hdr->csum_offset = offsetof(struct rte_tcp_hdr, cksum);
 635                         hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 636                         break;
 637
 638                 default:
 639                         ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0);
 640                         ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0);
 641                         ASSIGN_UNLESS_EQUAL(hdr->flags, 0);
 642                         break;
 643                 }
 644
 645                 /* TCP Segmentation Offload */
 646                 if (cookie->ol_flags & PKT_TX_TCP_SEG) {
 647                         hdr->gso_type = (cookie->ol_flags & PKT_TX_IPV6) ?
 648                                 VIRTIO_NET_HDR_GSO_TCPV6 :
 649                                 VIRTIO_NET_HDR_GSO_TCPV4;
 650                         hdr->gso_size = cookie->tso_segsz;
 651                         hdr->hdr_len =
 652                                 cookie->l2_len +
 653                                 cookie->l3_len +
 654                                 cookie->l4_len;
 655                 } else {
 656                         ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0);
 657                         ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0);
 658                         ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0);
 659                 }
 660         }
 661 }
 662
 663 static inline void
 664 virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 665                               uint16_t needed, int use_indirect, int can_push,
 666                               int in_order)
 667 {
 668         struct virtio_tx_region *txr = txvq->virtio_net_hdr_mz->addr;
 669         struct vq_desc_extra *dxp;
 670         struct virtqueue *vq = txvq->vq;
 671         struct vring_packed_desc *start_dp, *head_dp;
 672         uint16_t idx, id, head_idx, head_flags;
 673         int16_t head_size = vq->hw->vtnet_hdr_size;
 674         struct virtio_net_hdr *hdr;
 675         uint16_t prev;
 676         bool prepend_header = false;
 677         uint16_t seg_num = cookie->nb_segs;
 678
 679         id = in_order ? vq->vq_avail_idx : vq->vq_desc_head_idx;
 680
 681         dxp = &vq->vq_descx[id];
 682         dxp->ndescs = needed;
 683         dxp->cookie = cookie;
 684
 685         head_idx = vq->vq_avail_idx;
 686         idx = head_idx;
 687         prev = head_idx;
 688         start_dp = vq->vq_packed.ring.desc;
 689
 690         head_dp = &vq->vq_packed.ring.desc[idx];
 691         head_flags = cookie->next ? VRING_DESC_F_NEXT : 0;
 692         head_flags |= vq->vq_packed.cached_flags;
 693
 694         if (can_push) {
 695                 /* prepend cannot fail, checked by caller */
 696                 hdr = rte_pktmbuf_mtod_offset(cookie, struct virtio_net_hdr *,
 697                                               -head_size);
 698                 prepend_header = true;
 699
 700                 /* if offload disabled, it is not zeroed below, do it now */
 701                 if (!vq->hw->has_tx_offload)
 702                         virtqueue_clear_net_hdr(hdr);
 703         } else if (use_indirect) {
 704                 /* setup tx ring slot to point to indirect
 705                  * descriptor list stored in reserved region.
 706                  *
 707                  * the first slot in indirect ring is already preset
 708                  * to point to the header in reserved region
 709                  */
 710                 start_dp[idx].addr  = txvq->virtio_net_hdr_mem +
 711                         RTE_PTR_DIFF(&txr[idx].tx_packed_indir, txr);
 712                 start_dp[idx].len   = (seg_num + 1) *
 713                         sizeof(struct vring_packed_desc);
 714                 /* reset flags for indirect desc */
 715                 head_flags = VRING_DESC_F_INDIRECT;
 716                 head_flags |= vq->vq_packed.cached_flags;
 717                 hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
 718
 719                 /* loop below will fill in rest of the indirect elements */
 720                 start_dp = txr[idx].tx_packed_indir;
 721                 idx = 1;
 722         } else {
 723                 /* setup first tx ring slot to point to header
 724                  * stored in reserved region.
 725                  */
 726                 start_dp[idx].addr  = txvq->virtio_net_hdr_mem +
 727                         RTE_PTR_DIFF(&txr[idx].tx_hdr, txr);
 728                 start_dp[idx].len   = vq->hw->vtnet_hdr_size;
 729                 hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
 730                 idx++;
 731                 if (idx >= vq->vq_nentries) {
 732                         idx -= vq->vq_nentries;
 733                         vq->vq_packed.cached_flags ^=
 734                                 VRING_PACKED_DESC_F_AVAIL_USED;
 735                 }
 736         }
 737
 738         virtqueue_xmit_offload(hdr, cookie, vq->hw->has_tx_offload);
 739
 740         do {
 741                 uint16_t flags;
 742
 743                 start_dp[idx].addr = rte_mbuf_data_iova(cookie);
 744                 start_dp[idx].len  = cookie->data_len;
 745                 if (prepend_header) {
 746                         start_dp[idx].addr -= head_size;
 747                         start_dp[idx].len += head_size;
 748                         prepend_header = false;
 749                 }
 750
 751                 if (likely(idx != head_idx)) {
 752                         flags = cookie->next ? VRING_DESC_F_NEXT : 0;
 753                         flags |= vq->vq_packed.cached_flags;
 754                         start_dp[idx].flags = flags;
 755                 }
 756                 prev = idx;
 757                 idx++;
 758                 if (idx >= vq->vq_nentries) {
 759                         idx -= vq->vq_nentries;
 760                         vq->vq_packed.cached_flags ^=
 761                                 VRING_PACKED_DESC_F_AVAIL_USED;
 762                 }
 763         } while ((cookie = cookie->next) != NULL);
 764
 765         start_dp[prev].id = id;
 766
 767         if (use_indirect) {
 768                 idx = head_idx;
 769                 if (++idx >= vq->vq_nentries) {
 770                         idx -= vq->vq_nentries;
 771                         vq->vq_packed.cached_flags ^=
 772                                 VRING_PACKED_DESC_F_AVAIL_USED;
 773                 }
 774         }
 775
 776         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
 777         vq->vq_avail_idx = idx;
 778
 779         if (!in_order) {
 780                 vq->vq_desc_head_idx = dxp->next;
 781                 if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
 782                         vq->vq_desc_tail_idx = VQ_RING_DESC_CHAIN_END;
 783         }
 784
 785         virtqueue_store_flags_packed(head_dp, head_flags,
 786                                      vq->hw->weak_barriers);
 787 }
 788
 789 static void
 790 vq_ring_free_id_packed(struct virtqueue *vq, uint16_t id)
 791 {
 792         struct vq_desc_extra *dxp;
 793
 794         dxp = &vq->vq_descx[id];
 795         vq->vq_free_cnt += dxp->ndescs;
 796
 797         if (vq->vq_desc_tail_idx == VQ_RING_DESC_CHAIN_END)
 798                 vq->vq_desc_head_idx = id;
 799         else
 800                 vq->vq_descx[vq->vq_desc_tail_idx].next = id;
 801
 802         vq->vq_desc_tail_idx = id;
 803         dxp->next = VQ_RING_DESC_CHAIN_END;
 804 }
 805
 806 static void
 807 virtio_xmit_cleanup_inorder_packed(struct virtqueue *vq, int num)
 808 {
 809         uint16_t used_idx, id, curr_id, free_cnt = 0;
 810         uint16_t size = vq->vq_nentries;
 811         struct vring_packed_desc *desc = vq->vq_packed.ring.desc;
 812         struct vq_desc_extra *dxp;
 813
 814         used_idx = vq->vq_used_cons_idx;
 815         /* desc_is_used has a load-acquire or rte_io_rmb inside
 816          * and wait for used desc in virtqueue.
 817          */
 818         while (num > 0 && desc_is_used(&desc[used_idx], vq)) {
 819                 id = desc[used_idx].id;
 820                 do {
 821                         curr_id = used_idx;
 822                         dxp = &vq->vq_descx[used_idx];
 823                         used_idx += dxp->ndescs;
 824                         free_cnt += dxp->ndescs;
 825                         num -= dxp->ndescs;
 826                         if (used_idx >= size) {
 827                                 used_idx -= size;
 828                                 vq->vq_packed.used_wrap_counter ^= 1;
 829                         }
 830                         if (dxp->cookie != NULL) {
 831                                 rte_pktmbuf_free(dxp->cookie);
 832                                 dxp->cookie = NULL;
 833                         }
 834                 } while (curr_id != id);
 835         }
 836         vq->vq_used_cons_idx = used_idx;
 837         vq->vq_free_cnt += free_cnt;
 838 }
 839
 840 static void
 841 virtio_xmit_cleanup_normal_packed(struct virtqueue *vq, int num)
 842 {
 843         uint16_t used_idx, id;
 844         uint16_t size = vq->vq_nentries;
 845         struct vring_packed_desc *desc = vq->vq_packed.ring.desc;
 846         struct vq_desc_extra *dxp;
 847
 848         used_idx = vq->vq_used_cons_idx;
 849         /* desc_is_used has a load-acquire or rte_io_rmb inside
 850          * and wait for used desc in virtqueue.
 851          */
 852         while (num-- && desc_is_used(&desc[used_idx], vq)) {
 853                 id = desc[used_idx].id;
 854                 dxp = &vq->vq_descx[id];
 855                 vq->vq_used_cons_idx += dxp->ndescs;
 856                 if (vq->vq_used_cons_idx >= size) {
 857                         vq->vq_used_cons_idx -= size;
 858                         vq->vq_packed.used_wrap_counter ^= 1;
 859                 }
 860                 vq_ring_free_id_packed(vq, id);
 861                 if (dxp->cookie != NULL) {
 862                         rte_pktmbuf_free(dxp->cookie);
 863                         dxp->cookie = NULL;
 864                 }
 865                 used_idx = vq->vq_used_cons_idx;
 866         }
 867 }
 868
 869 /* Cleanup from completed transmits. */
 870 static inline void
 871 virtio_xmit_cleanup_packed(struct virtqueue *vq, int num, int in_order)
 872 {
 873         if (in_order)
 874                 virtio_xmit_cleanup_inorder_packed(vq, num);
 875         else
 876                 virtio_xmit_cleanup_normal_packed(vq, num);
 877 }
 878
 879 static inline void
 880 virtio_xmit_cleanup(struct virtqueue *vq, uint16_t num)
 881 {
 882         uint16_t i, used_idx, desc_idx;
 883         for (i = 0; i < num; i++) {
 884                 struct vring_used_elem *uep;
 885                 struct vq_desc_extra *dxp;
 886
 887                 used_idx = (uint16_t)(vq->vq_used_cons_idx &
 888                                 (vq->vq_nentries - 1));
 889                 uep = &vq->vq_split.ring.used->ring[used_idx];
 890
 891                 desc_idx = (uint16_t)uep->id;
 892                 dxp = &vq->vq_descx[desc_idx];
 893                 vq->vq_used_cons_idx++;
 894                 vq_ring_free_chain(vq, desc_idx);
 895
 896                 if (dxp->cookie != NULL) {
 897                         rte_pktmbuf_free(dxp->cookie);
 898                         dxp->cookie = NULL;
 899                 }
 900         }
 901 }
 902
 903 /* Cleanup from completed inorder transmits. */
 904 static __rte_always_inline void
 905 virtio_xmit_cleanup_inorder(struct virtqueue *vq, uint16_t num)
 906 {
 907         uint16_t i, idx = vq->vq_used_cons_idx;
 908         int16_t free_cnt = 0;
 909         struct vq_desc_extra *dxp = NULL;
 910
 911         if (unlikely(num == 0))
 912                 return;
 913
 914         for (i = 0; i < num; i++) {
 915                 dxp = &vq->vq_descx[idx++ & (vq->vq_nentries - 1)];
 916                 free_cnt += dxp->ndescs;
 917                 if (dxp->cookie != NULL) {
 918                         rte_pktmbuf_free(dxp->cookie);
 919                         dxp->cookie = NULL;
 920                 }
 921         }
 922
 923         vq->vq_free_cnt += free_cnt;
 924         vq->vq_used_cons_idx = idx;
 925 }
 926 #endif /* _VIRTQUEUE_H_ */