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 #define virtnet_rxq_to_vq(rxvq) container_of(rxvq, struct virtqueue, rxq)
 221 #define virtnet_txq_to_vq(txvq) container_of(txvq, struct virtqueue, txq)
 222 #define virtnet_cq_to_vq(cvq) container_of(cvq, struct virtqueue, cq)
 223
 224 struct virtqueue {
 225         struct virtio_hw  *hw; /**< virtio_hw structure pointer. */
 226         union {
 227                 struct {
 228                         /**< vring keeping desc, used and avail */
 229                         struct vring ring;
 230                 } vq_split;
 231
 232                 struct {
 233                         /**< vring keeping descs and events */
 234                         struct vring_packed ring;
 235                         bool used_wrap_counter;
 236                         uint16_t cached_flags; /**< cached flags for descs */
 237                         uint16_t event_flags_shadow;
 238                 } vq_packed;
 239         };
 240
 241         uint16_t vq_used_cons_idx; /**< last consumed descriptor */
 242         uint16_t vq_nentries;  /**< vring desc numbers */
 243         uint16_t vq_free_cnt;  /**< num of desc available */
 244         uint16_t vq_avail_idx; /**< sync until needed */
 245         uint16_t vq_free_thresh; /**< free threshold */
 246
 247         /**
 248          * Head of the free chain in the descriptor table. If
 249          * there are no free descriptors, this will be set to
 250          * VQ_RING_DESC_CHAIN_END.
 251          */
 252         uint16_t  vq_desc_head_idx;
 253         uint16_t  vq_desc_tail_idx;
 254         uint16_t  vq_queue_index;   /**< PCI queue index */
 255
 256         void *vq_ring_virt_mem;  /**< linear address of vring*/
 257         unsigned int vq_ring_size;
 258
 259         union {
 260                 struct virtnet_rx rxq;
 261                 struct virtnet_tx txq;
 262                 struct virtnet_ctl cq;
 263         };
 264
 265         rte_iova_t vq_ring_mem; /**< physical address of vring,
 266                                  * or virtual address for virtio_user. */
 267
 268         uint16_t  *notify_addr;
 269         struct rte_mbuf **sw_ring;  /**< RX software ring. */
 270         struct vq_desc_extra vq_descx[0];
 271 };
 272
 273 /* If multiqueue is provided by host, then we suppport it. */
 274 #define VIRTIO_NET_CTRL_MQ   4
 275 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET        0
 276 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN        1
 277 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX        0x8000
 278
 279 /**
 280  * This is the first element of the scatter-gather list.  If you don't
 281  * specify GSO or CSUM features, you can simply ignore the header.
 282  */
 283 struct virtio_net_hdr {
 284 #define VIRTIO_NET_HDR_F_NEEDS_CSUM 1    /**< Use csum_start,csum_offset*/
 285 #define VIRTIO_NET_HDR_F_DATA_VALID 2    /**< Checksum is valid */
 286         uint8_t flags;
 287 #define VIRTIO_NET_HDR_GSO_NONE     0    /**< Not a GSO frame */
 288 #define VIRTIO_NET_HDR_GSO_TCPV4    1    /**< GSO frame, IPv4 TCP (TSO) */
 289 #define VIRTIO_NET_HDR_GSO_UDP      3    /**< GSO frame, IPv4 UDP (UFO) */
 290 #define VIRTIO_NET_HDR_GSO_TCPV6    4    /**< GSO frame, IPv6 TCP */
 291 #define VIRTIO_NET_HDR_GSO_ECN      0x80 /**< TCP has ECN set */
 292         uint8_t gso_type;
 293         uint16_t hdr_len;     /**< Ethernet + IP + tcp/udp hdrs */
 294         uint16_t gso_size;    /**< Bytes to append to hdr_len per frame */
 295         uint16_t csum_start;  /**< Position to start checksumming from */
 296         uint16_t csum_offset; /**< Offset after that to place checksum */
 297 };
 298
 299 /**
 300  * This is the version of the header to use when the MRG_RXBUF
 301  * feature has been negotiated.
 302  */
 303 struct virtio_net_hdr_mrg_rxbuf {
 304         struct   virtio_net_hdr hdr;
 305         uint16_t num_buffers; /**< Number of merged rx buffers */
 306 };
 307
 308 /* Region reserved to allow for transmit header and indirect ring */
 309 #define VIRTIO_MAX_TX_INDIRECT 8
 310 struct virtio_tx_region {
 311         struct virtio_net_hdr_mrg_rxbuf tx_hdr;
 312         union {
 313                 struct vring_desc tx_indir[VIRTIO_MAX_TX_INDIRECT];
 314                 struct vring_packed_desc
 315                         tx_packed_indir[VIRTIO_MAX_TX_INDIRECT];
 316         } __rte_aligned(16);
 317 };
 318
 319 static inline int
 320 desc_is_used(struct vring_packed_desc *desc, struct virtqueue *vq)
 321 {
 322         uint16_t used, avail, flags;
 323
 324         flags = virtqueue_fetch_flags_packed(desc, vq->hw->weak_barriers);
 325         used = !!(flags & VRING_PACKED_DESC_F_USED);
 326         avail = !!(flags & VRING_PACKED_DESC_F_AVAIL);
 327
 328         return avail == used && used == vq->vq_packed.used_wrap_counter;
 329 }
 330
 331 static inline void
 332 vring_desc_init_packed(struct virtqueue *vq, int n)
 333 {
 334         int i;
 335         for (i = 0; i < n - 1; i++) {
 336                 vq->vq_packed.ring.desc[i].id = i;
 337                 vq->vq_descx[i].next = i + 1;
 338         }
 339         vq->vq_packed.ring.desc[i].id = i;
 340         vq->vq_descx[i].next = VQ_RING_DESC_CHAIN_END;
 341 }
 342
 343 /* Chain all the descriptors in the ring with an END */
 344 static inline void
 345 vring_desc_init_split(struct vring_desc *dp, uint16_t n)
 346 {
 347         uint16_t i;
 348
 349         for (i = 0; i < n - 1; i++)
 350                 dp[i].next = (uint16_t)(i + 1);
 351         dp[i].next = VQ_RING_DESC_CHAIN_END;
 352 }
 353
 354 static inline void
 355 vring_desc_init_indirect_packed(struct vring_packed_desc *dp, int n)
 356 {
 357         int i;
 358         for (i = 0; i < n; i++) {
 359                 dp[i].id = (uint16_t)i;
 360                 dp[i].flags = VRING_DESC_F_WRITE;
 361         }
 362 }
 363
 364 /**
 365  * Tell the backend not to interrupt us. Implementation for packed virtqueues.
 366  */
 367 static inline void
 368 virtqueue_disable_intr_packed(struct virtqueue *vq)
 369 {
 370         if (vq->vq_packed.event_flags_shadow != RING_EVENT_FLAGS_DISABLE) {
 371                 vq->vq_packed.event_flags_shadow = RING_EVENT_FLAGS_DISABLE;
 372                 vq->vq_packed.ring.driver->desc_event_flags =
 373                         vq->vq_packed.event_flags_shadow;
 374         }
 375 }
 376
 377 /**
 378  * Tell the backend not to interrupt us. Implementation for split virtqueues.
 379  */
 380 static inline void
 381 virtqueue_disable_intr_split(struct virtqueue *vq)
 382 {
 383         vq->vq_split.ring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
 384 }
 385
 386 /**
 387  * Tell the backend not to interrupt us.
 388  */
 389 static inline void
 390 virtqueue_disable_intr(struct virtqueue *vq)
 391 {
 392         if (virtio_with_packed_queue(vq->hw))
 393                 virtqueue_disable_intr_packed(vq);
 394         else
 395                 virtqueue_disable_intr_split(vq);
 396 }
 397
 398 /**
 399  * Tell the backend to interrupt. Implementation for packed virtqueues.
 400  */
 401 static inline void
 402 virtqueue_enable_intr_packed(struct virtqueue *vq)
 403 {
 404         if (vq->vq_packed.event_flags_shadow == RING_EVENT_FLAGS_DISABLE) {
 405                 vq->vq_packed.event_flags_shadow = RING_EVENT_FLAGS_ENABLE;
 406                 vq->vq_packed.ring.driver->desc_event_flags =
 407                         vq->vq_packed.event_flags_shadow;
 408         }
 409 }
 410
 411 /**
 412  * Tell the backend to interrupt. Implementation for split virtqueues.
 413  */
 414 static inline void
 415 virtqueue_enable_intr_split(struct virtqueue *vq)
 416 {
 417         vq->vq_split.ring.avail->flags &= (~VRING_AVAIL_F_NO_INTERRUPT);
 418 }
 419
 420 /**
 421  * Tell the backend to interrupt us.
 422  */
 423 static inline void
 424 virtqueue_enable_intr(struct virtqueue *vq)
 425 {
 426         if (virtio_with_packed_queue(vq->hw))
 427                 virtqueue_enable_intr_packed(vq);
 428         else
 429                 virtqueue_enable_intr_split(vq);
 430 }
 431
 432 /**
 433  *  Dump virtqueue internal structures, for debug purpose only.
 434  */
 435 void virtqueue_dump(struct virtqueue *vq);
 436 /**
 437  *  Get all mbufs to be freed.
 438  */
 439 struct rte_mbuf *virtqueue_detach_unused(struct virtqueue *vq);
 440
 441 /* Flush the elements in the used ring. */
 442 void virtqueue_rxvq_flush(struct virtqueue *vq);
 443
 444 int virtqueue_rxvq_reset_packed(struct virtqueue *vq);
 445
 446 int virtqueue_txvq_reset_packed(struct virtqueue *vq);
 447
 448 static inline int
 449 virtqueue_full(const struct virtqueue *vq)
 450 {
 451         return vq->vq_free_cnt == 0;
 452 }
 453
 454 static inline int
 455 virtio_get_queue_type(struct virtio_hw *hw, uint16_t vq_idx)
 456 {
 457         if (vq_idx == hw->max_queue_pairs * 2)
 458                 return VTNET_CQ;
 459         else if (vq_idx % 2 == 0)
 460                 return VTNET_RQ;
 461         else
 462                 return VTNET_TQ;
 463 }
 464
 465 /* virtqueue_nused has load-acquire or rte_io_rmb insed */
 466 static inline uint16_t
 467 virtqueue_nused(const struct virtqueue *vq)
 468 {
 469         uint16_t idx;
 470
 471         if (vq->hw->weak_barriers) {
 472         /**
 473          * x86 prefers to using rte_smp_rmb over __atomic_load_n as it
 474          * reports a slightly better perf, which comes from the saved
 475          * branch by the compiler.
 476          * The if and else branches are identical with the smp and io
 477          * barriers both defined as compiler barriers on x86.
 478          */
 479 #ifdef RTE_ARCH_X86_64
 480                 idx = vq->vq_split.ring.used->idx;
 481                 rte_smp_rmb();
 482 #else
 483                 idx = __atomic_load_n(&(vq)->vq_split.ring.used->idx,
 484                                 __ATOMIC_ACQUIRE);
 485 #endif
 486         } else {
 487                 idx = vq->vq_split.ring.used->idx;
 488                 rte_io_rmb();
 489         }
 490         return idx - vq->vq_used_cons_idx;
 491 }
 492
 493 void vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx);
 494 void vq_ring_free_chain_packed(struct virtqueue *vq, uint16_t used_idx);
 495 void vq_ring_free_inorder(struct virtqueue *vq, uint16_t desc_idx,
 496                           uint16_t num);
 497
 498 static inline void
 499 vq_update_avail_idx(struct virtqueue *vq)
 500 {
 501         if (vq->hw->weak_barriers) {
 502         /* x86 prefers to using rte_smp_wmb over __atomic_store_n as
 503          * it reports a slightly better perf, which comes from the
 504          * saved branch by the compiler.
 505          * The if and else branches are identical with the smp and
 506          * io barriers both defined as compiler barriers on x86.
 507          */
 508 #ifdef RTE_ARCH_X86_64
 509                 rte_smp_wmb();
 510                 vq->vq_split.ring.avail->idx = vq->vq_avail_idx;
 511 #else
 512                 __atomic_store_n(&vq->vq_split.ring.avail->idx,
 513                                  vq->vq_avail_idx, __ATOMIC_RELEASE);
 514 #endif
 515         } else {
 516                 rte_io_wmb();
 517                 vq->vq_split.ring.avail->idx = vq->vq_avail_idx;
 518         }
 519 }
 520
 521 static inline void
 522 vq_update_avail_ring(struct virtqueue *vq, uint16_t desc_idx)
 523 {
 524         uint16_t avail_idx;
 525         /*
 526          * Place the head of the descriptor chain into the next slot and make
 527          * it usable to the host. The chain is made available now rather than
 528          * deferring to virtqueue_notify() in the hopes that if the host is
 529          * currently running on another CPU, we can keep it processing the new
 530          * descriptor.
 531          */
 532         avail_idx = (uint16_t)(vq->vq_avail_idx & (vq->vq_nentries - 1));
 533         if (unlikely(vq->vq_split.ring.avail->ring[avail_idx] != desc_idx))
 534                 vq->vq_split.ring.avail->ring[avail_idx] = desc_idx;
 535         vq->vq_avail_idx++;
 536 }
 537
 538 static inline int
 539 virtqueue_kick_prepare(struct virtqueue *vq)
 540 {
 541         /*
 542          * Ensure updated avail->idx is visible to vhost before reading
 543          * the used->flags.
 544          */
 545         virtio_mb(vq->hw->weak_barriers);
 546         return !(vq->vq_split.ring.used->flags & VRING_USED_F_NO_NOTIFY);
 547 }
 548
 549 static inline int
 550 virtqueue_kick_prepare_packed(struct virtqueue *vq)
 551 {
 552         uint16_t flags;
 553
 554         /*
 555          * Ensure updated data is visible to vhost before reading the flags.
 556          */
 557         virtio_mb(vq->hw->weak_barriers);
 558         flags = vq->vq_packed.ring.device->desc_event_flags;
 559
 560         return flags != RING_EVENT_FLAGS_DISABLE;
 561 }
 562
 563 /*
 564  * virtqueue_kick_prepare*() or the virtio_wmb() should be called
 565  * before this function to be sure that all the data is visible to vhost.
 566  */
 567 static inline void
 568 virtqueue_notify(struct virtqueue *vq)
 569 {
 570         VIRTIO_OPS(vq->hw)->notify_queue(vq->hw, vq);
 571 }
 572
 573 #ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
 574 #define VIRTQUEUE_DUMP(vq) do { \
 575         uint16_t used_idx, nused; \
 576         used_idx = __atomic_load_n(&(vq)->vq_split.ring.used->idx, \
 577                                    __ATOMIC_RELAXED); \
 578         nused = (uint16_t)(used_idx - (vq)->vq_used_cons_idx); \
 579         if (virtio_with_packed_queue((vq)->hw)) { \
 580                 PMD_INIT_LOG(DEBUG, \
 581                 "VQ: - size=%d; free=%d; used_cons_idx=%d; avail_idx=%d;" \
 582                 " cached_flags=0x%x; used_wrap_counter=%d", \
 583                 (vq)->vq_nentries, (vq)->vq_free_cnt, (vq)->vq_used_cons_idx, \
 584                 (vq)->vq_avail_idx, (vq)->vq_packed.cached_flags, \
 585                 (vq)->vq_packed.used_wrap_counter); \
 586                 break; \
 587         } \
 588         PMD_INIT_LOG(DEBUG, \
 589           "VQ: - size=%d; free=%d; used=%d; desc_head_idx=%d;" \
 590           " avail.idx=%d; used_cons_idx=%d; used.idx=%d;" \
 591           " avail.flags=0x%x; used.flags=0x%x", \
 592           (vq)->vq_nentries, (vq)->vq_free_cnt, nused, (vq)->vq_desc_head_idx, \
 593           (vq)->vq_split.ring.avail->idx, (vq)->vq_used_cons_idx, \
 594           __atomic_load_n(&(vq)->vq_split.ring.used->idx, __ATOMIC_RELAXED), \
 595           (vq)->vq_split.ring.avail->flags, (vq)->vq_split.ring.used->flags); \
 596 } while (0)
 597 #else
 598 #define VIRTQUEUE_DUMP(vq) do { } while (0)
 599 #endif
 600
 601 /* avoid write operation when necessary, to lessen cache issues */
 602 #define ASSIGN_UNLESS_EQUAL(var, val) do {      \
 603         typeof(var) *const var_ = &(var);       \
 604         typeof(val)  const val_ = (val);        \
 605         if (*var_ != val_)                      \
 606                 *var_ = val_;                   \
 607 } while (0)
 608
 609 #define virtqueue_clear_net_hdr(hdr) do {               \
 610         typeof(hdr) hdr_ = (hdr);                       \
 611         ASSIGN_UNLESS_EQUAL((hdr_)->csum_start, 0);     \
 612         ASSIGN_UNLESS_EQUAL((hdr_)->csum_offset, 0);    \
 613         ASSIGN_UNLESS_EQUAL((hdr_)->flags, 0);          \
 614         ASSIGN_UNLESS_EQUAL((hdr_)->gso_type, 0);       \
 615         ASSIGN_UNLESS_EQUAL((hdr_)->gso_size, 0);       \
 616         ASSIGN_UNLESS_EQUAL((hdr_)->hdr_len, 0);        \
 617 } while (0)
 618
 619 static inline void
 620 virtqueue_xmit_offload(struct virtio_net_hdr *hdr,
 621                         struct rte_mbuf *cookie,
 622                         uint8_t offload)
 623 {
 624         if (offload) {
 625                 uint64_t csum_l4 = cookie->ol_flags & PKT_TX_L4_MASK;
 626
 627                 if (cookie->ol_flags & PKT_TX_TCP_SEG)
 628                         csum_l4 |= PKT_TX_TCP_CKSUM;
 629
 630                 switch (csum_l4) {
 631                 case PKT_TX_UDP_CKSUM:
 632                         hdr->csum_start = cookie->l2_len + cookie->l3_len;
 633                         hdr->csum_offset = offsetof(struct rte_udp_hdr,
 634                                 dgram_cksum);
 635                         hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 636                         break;
 637
 638                 case PKT_TX_TCP_CKSUM:
 639                         hdr->csum_start = cookie->l2_len + cookie->l3_len;
 640                         hdr->csum_offset = offsetof(struct rte_tcp_hdr, cksum);
 641                         hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
 642                         break;
 643
 644                 default:
 645                         ASSIGN_UNLESS_EQUAL(hdr->csum_start, 0);
 646                         ASSIGN_UNLESS_EQUAL(hdr->csum_offset, 0);
 647                         ASSIGN_UNLESS_EQUAL(hdr->flags, 0);
 648                         break;
 649                 }
 650
 651                 /* TCP Segmentation Offload */
 652                 if (cookie->ol_flags & PKT_TX_TCP_SEG) {
 653                         hdr->gso_type = (cookie->ol_flags & PKT_TX_IPV6) ?
 654                                 VIRTIO_NET_HDR_GSO_TCPV6 :
 655                                 VIRTIO_NET_HDR_GSO_TCPV4;
 656                         hdr->gso_size = cookie->tso_segsz;
 657                         hdr->hdr_len =
 658                                 cookie->l2_len +
 659                                 cookie->l3_len +
 660                                 cookie->l4_len;
 661                 } else {
 662                         ASSIGN_UNLESS_EQUAL(hdr->gso_type, 0);
 663                         ASSIGN_UNLESS_EQUAL(hdr->gso_size, 0);
 664                         ASSIGN_UNLESS_EQUAL(hdr->hdr_len, 0);
 665                 }
 666         }
 667 }
 668
 669 static inline void
 670 virtqueue_enqueue_xmit_packed(struct virtnet_tx *txvq, struct rte_mbuf *cookie,
 671                               uint16_t needed, int use_indirect, int can_push,
 672                               int in_order)
 673 {
 674         struct virtio_tx_region *txr = txvq->virtio_net_hdr_mz->addr;
 675         struct vq_desc_extra *dxp;
 676         struct virtqueue *vq = virtnet_txq_to_vq(txvq);
 677         struct vring_packed_desc *start_dp, *head_dp;
 678         uint16_t idx, id, head_idx, head_flags;
 679         int16_t head_size = vq->hw->vtnet_hdr_size;
 680         struct virtio_net_hdr *hdr;
 681         uint16_t prev;
 682         bool prepend_header = false;
 683         uint16_t seg_num = cookie->nb_segs;
 684
 685         id = in_order ? vq->vq_avail_idx : vq->vq_desc_head_idx;
 686
 687         dxp = &vq->vq_descx[id];
 688         dxp->ndescs = needed;
 689         dxp->cookie = cookie;
 690
 691         head_idx = vq->vq_avail_idx;
 692         idx = head_idx;
 693         prev = head_idx;
 694         start_dp = vq->vq_packed.ring.desc;
 695
 696         head_dp = &vq->vq_packed.ring.desc[idx];
 697         head_flags = cookie->next ? VRING_DESC_F_NEXT : 0;
 698         head_flags |= vq->vq_packed.cached_flags;
 699
 700         if (can_push) {
 701                 /* prepend cannot fail, checked by caller */
 702                 hdr = rte_pktmbuf_mtod_offset(cookie, struct virtio_net_hdr *,
 703                                               -head_size);
 704                 prepend_header = true;
 705
 706                 /* if offload disabled, it is not zeroed below, do it now */
 707                 if (!vq->hw->has_tx_offload)
 708                         virtqueue_clear_net_hdr(hdr);
 709         } else if (use_indirect) {
 710                 /* setup tx ring slot to point to indirect
 711                  * descriptor list stored in reserved region.
 712                  *
 713                  * the first slot in indirect ring is already preset
 714                  * to point to the header in reserved region
 715                  */
 716                 start_dp[idx].addr  = txvq->virtio_net_hdr_mem +
 717                         RTE_PTR_DIFF(&txr[idx].tx_packed_indir, txr);
 718                 start_dp[idx].len   = (seg_num + 1) *
 719                         sizeof(struct vring_packed_desc);
 720                 /* reset flags for indirect desc */
 721                 head_flags = VRING_DESC_F_INDIRECT;
 722                 head_flags |= vq->vq_packed.cached_flags;
 723                 hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
 724
 725                 /* loop below will fill in rest of the indirect elements */
 726                 start_dp = txr[idx].tx_packed_indir;
 727                 idx = 1;
 728         } else {
 729                 /* setup first tx ring slot to point to header
 730                  * stored in reserved region.
 731                  */
 732                 start_dp[idx].addr  = txvq->virtio_net_hdr_mem +
 733                         RTE_PTR_DIFF(&txr[idx].tx_hdr, txr);
 734                 start_dp[idx].len   = vq->hw->vtnet_hdr_size;
 735                 hdr = (struct virtio_net_hdr *)&txr[idx].tx_hdr;
 736                 idx++;
 737                 if (idx >= vq->vq_nentries) {
 738                         idx -= vq->vq_nentries;
 739                         vq->vq_packed.cached_flags ^=
 740                                 VRING_PACKED_DESC_F_AVAIL_USED;
 741                 }
 742         }
 743
 744         virtqueue_xmit_offload(hdr, cookie, vq->hw->has_tx_offload);
 745
 746         do {
 747                 uint16_t flags;
 748
 749                 start_dp[idx].addr = rte_mbuf_data_iova(cookie);
 750                 start_dp[idx].len  = cookie->data_len;
 751                 if (prepend_header) {
 752                         start_dp[idx].addr -= head_size;
 753                         start_dp[idx].len += head_size;
 754                         prepend_header = false;
 755                 }
 756
 757                 if (likely(idx != head_idx)) {
 758                         flags = cookie->next ? VRING_DESC_F_NEXT : 0;
 759                         flags |= vq->vq_packed.cached_flags;
 760                         start_dp[idx].flags = flags;
 761                 }
 762                 prev = idx;
 763                 idx++;
 764                 if (idx >= vq->vq_nentries) {
 765                         idx -= vq->vq_nentries;
 766                         vq->vq_packed.cached_flags ^=
 767                                 VRING_PACKED_DESC_F_AVAIL_USED;
 768                 }
 769         } while ((cookie = cookie->next) != NULL);
 770
 771         start_dp[prev].id = id;
 772
 773         if (use_indirect) {
 774                 idx = head_idx;
 775                 if (++idx >= vq->vq_nentries) {
 776                         idx -= vq->vq_nentries;
 777                         vq->vq_packed.cached_flags ^=
 778                                 VRING_PACKED_DESC_F_AVAIL_USED;
 779                 }
 780         }
 781
 782         vq->vq_free_cnt = (uint16_t)(vq->vq_free_cnt - needed);
 783         vq->vq_avail_idx = idx;
 784
 785         if (!in_order) {
 786                 vq->vq_desc_head_idx = dxp->next;
 787                 if (vq->vq_desc_head_idx == VQ_RING_DESC_CHAIN_END)
 788                         vq->vq_desc_tail_idx = VQ_RING_DESC_CHAIN_END;
 789         }
 790
 791         virtqueue_store_flags_packed(head_dp, head_flags,
 792                                      vq->hw->weak_barriers);
 793 }
 794
 795 static void
 796 vq_ring_free_id_packed(struct virtqueue *vq, uint16_t id)
 797 {
 798         struct vq_desc_extra *dxp;
 799
 800         dxp = &vq->vq_descx[id];
 801         vq->vq_free_cnt += dxp->ndescs;
 802
 803         if (vq->vq_desc_tail_idx == VQ_RING_DESC_CHAIN_END)
 804                 vq->vq_desc_head_idx = id;
 805         else
 806                 vq->vq_descx[vq->vq_desc_tail_idx].next = id;
 807
 808         vq->vq_desc_tail_idx = id;
 809         dxp->next = VQ_RING_DESC_CHAIN_END;
 810 }
 811
 812 static void
 813 virtio_xmit_cleanup_inorder_packed(struct virtqueue *vq, int num)
 814 {
 815         uint16_t used_idx, id, curr_id, free_cnt = 0;
 816         uint16_t size = vq->vq_nentries;
 817         struct vring_packed_desc *desc = vq->vq_packed.ring.desc;
 818         struct vq_desc_extra *dxp;
 819
 820         used_idx = vq->vq_used_cons_idx;
 821         /* desc_is_used has a load-acquire or rte_io_rmb inside
 822          * and wait for used desc in virtqueue.
 823          */
 824         while (num > 0 && desc_is_used(&desc[used_idx], vq)) {
 825                 id = desc[used_idx].id;
 826                 do {
 827                         curr_id = used_idx;
 828                         dxp = &vq->vq_descx[used_idx];
 829                         used_idx += dxp->ndescs;
 830                         free_cnt += dxp->ndescs;
 831                         num -= dxp->ndescs;
 832                         if (used_idx >= size) {
 833                                 used_idx -= size;
 834                                 vq->vq_packed.used_wrap_counter ^= 1;
 835                         }
 836                         if (dxp->cookie != NULL) {
 837                                 rte_pktmbuf_free(dxp->cookie);
 838                                 dxp->cookie = NULL;
 839                         }
 840                 } while (curr_id != id);
 841         }
 842         vq->vq_used_cons_idx = used_idx;
 843         vq->vq_free_cnt += free_cnt;
 844 }
 845
 846 static void
 847 virtio_xmit_cleanup_normal_packed(struct virtqueue *vq, int num)
 848 {
 849         uint16_t used_idx, id;
 850         uint16_t size = vq->vq_nentries;
 851         struct vring_packed_desc *desc = vq->vq_packed.ring.desc;
 852         struct vq_desc_extra *dxp;
 853
 854         used_idx = vq->vq_used_cons_idx;
 855         /* desc_is_used has a load-acquire or rte_io_rmb inside
 856          * and wait for used desc in virtqueue.
 857          */
 858         while (num-- && desc_is_used(&desc[used_idx], vq)) {
 859                 id = desc[used_idx].id;
 860                 dxp = &vq->vq_descx[id];
 861                 vq->vq_used_cons_idx += dxp->ndescs;
 862                 if (vq->vq_used_cons_idx >= size) {
 863                         vq->vq_used_cons_idx -= size;
 864                         vq->vq_packed.used_wrap_counter ^= 1;
 865                 }
 866                 vq_ring_free_id_packed(vq, id);
 867                 if (dxp->cookie != NULL) {
 868                         rte_pktmbuf_free(dxp->cookie);
 869                         dxp->cookie = NULL;
 870                 }
 871                 used_idx = vq->vq_used_cons_idx;
 872         }
 873 }
 874
 875 /* Cleanup from completed transmits. */
 876 static inline void
 877 virtio_xmit_cleanup_packed(struct virtqueue *vq, int num, int in_order)
 878 {
 879         if (in_order)
 880                 virtio_xmit_cleanup_inorder_packed(vq, num);
 881         else
 882                 virtio_xmit_cleanup_normal_packed(vq, num);
 883 }
 884
 885 static inline void
 886 virtio_xmit_cleanup(struct virtqueue *vq, uint16_t num)
 887 {
 888         uint16_t i, used_idx, desc_idx;
 889         for (i = 0; i < num; i++) {
 890                 struct vring_used_elem *uep;
 891                 struct vq_desc_extra *dxp;
 892
 893                 used_idx = (uint16_t)(vq->vq_used_cons_idx &
 894                                 (vq->vq_nentries - 1));
 895                 uep = &vq->vq_split.ring.used->ring[used_idx];
 896
 897                 desc_idx = (uint16_t)uep->id;
 898                 dxp = &vq->vq_descx[desc_idx];
 899                 vq->vq_used_cons_idx++;
 900                 vq_ring_free_chain(vq, desc_idx);
 901
 902                 if (dxp->cookie != NULL) {
 903                         rte_pktmbuf_free(dxp->cookie);
 904                         dxp->cookie = NULL;
 905                 }
 906         }
 907 }
 908
 909 /* Cleanup from completed inorder transmits. */
 910 static __rte_always_inline void
 911 virtio_xmit_cleanup_inorder(struct virtqueue *vq, uint16_t num)
 912 {
 913         uint16_t i, idx = vq->vq_used_cons_idx;
 914         int16_t free_cnt = 0;
 915         struct vq_desc_extra *dxp = NULL;
 916
 917         if (unlikely(num == 0))
 918                 return;
 919
 920         for (i = 0; i < num; i++) {
 921                 dxp = &vq->vq_descx[idx++ & (vq->vq_nentries - 1)];
 922                 free_cnt += dxp->ndescs;
 923                 if (dxp->cookie != NULL) {
 924                         rte_pktmbuf_free(dxp->cookie);
 925                         dxp->cookie = NULL;
 926                 }
 927         }
 928
 929         vq->vq_free_cnt += free_cnt;
 930         vq->vq_used_cons_idx = idx;
 931 }
 932 #endif /* _VIRTQUEUE_H_ */