ceph/src/spdk/dpdk/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
  14 #include "virtio_pci.h"
  15 #include "virtio_ring.h"
  16 #include "virtio_logs.h"
  17 #include "virtio_rxtx.h"
  18
  19 struct rte_mbuf;
  20
  21 /*
  22  * Per virtio_ring.h in Linux.
  23  *     For virtio_pci on SMP, we don't need to order with respect to MMIO
  24  *     accesses through relaxed memory I/O windows, so smp_mb() et al are
  25  *     sufficient.
  26  *
  27  *     For using virtio to talk to real devices (eg. vDPA) we do need real
  28  *     barriers.
  29  */
  30 static inline void
  31 virtio_mb(uint8_t weak_barriers)
  32 {
  33         if (weak_barriers)
  34                 rte_smp_mb();
  35         else
  36                 rte_mb();
  37 }
  38
  39 static inline void
  40 virtio_rmb(uint8_t weak_barriers)
  41 {
  42         if (weak_barriers)
  43                 rte_smp_rmb();
  44         else
  45                 rte_cio_rmb();
  46 }
  47
  48 static inline void
  49 virtio_wmb(uint8_t weak_barriers)
  50 {
  51         if (weak_barriers)
  52                 rte_smp_wmb();
  53         else
  54                 rte_cio_wmb();
  55 }
  56
  57 #ifdef RTE_PMD_PACKET_PREFETCH
  58 #define rte_packet_prefetch(p)  rte_prefetch1(p)
  59 #else
  60 #define rte_packet_prefetch(p)  do {} while(0)
  61 #endif
  62
  63 #define VIRTQUEUE_MAX_NAME_SZ 32
  64
  65 #ifdef RTE_VIRTIO_USER
  66 /**
  67  * Return the physical address (or virtual address in case of
  68  * virtio-user) of mbuf data buffer.
  69  *
  70  * The address is firstly casted to the word size (sizeof(uintptr_t))
  71  * before casting it to uint64_t. This is to make it work with different
  72  * combination of word size (64 bit and 32 bit) and virtio device
  73  * (virtio-pci and virtio-user).
  74  */
  75 #define VIRTIO_MBUF_ADDR(mb, vq) \
  76         ((uint64_t)(*(uintptr_t *)((uintptr_t)(mb) + (vq)->offset)))
  77 #else
  78 #define VIRTIO_MBUF_ADDR(mb, vq) ((mb)->buf_iova)
  79 #endif
  80
  81 /**
  82  * Return the physical address (or virtual address in case of
  83  * virtio-user) of mbuf data buffer, taking care of mbuf data offset
  84  */
  85 #define VIRTIO_MBUF_DATA_DMA_ADDR(mb, vq) \
  86         (VIRTIO_MBUF_ADDR(mb, vq) + (mb)->data_off)
  87
  88 #define VTNET_SQ_RQ_QUEUE_IDX 0
  89 #define VTNET_SQ_TQ_QUEUE_IDX 1
  90 #define VTNET_SQ_CQ_QUEUE_IDX 2
  91
  92 enum { VTNET_RQ = 0, VTNET_TQ = 1, VTNET_CQ = 2 };
  93 /**
  94  * The maximum virtqueue size is 2^15. Use that value as the end of
  95  * descriptor chain terminator since it will never be a valid index
  96  * in the descriptor table. This is used to verify we are correctly
  97  * handling vq_free_cnt.
  98  */
  99 #define VQ_RING_DESC_CHAIN_END 32768
 100
 101 /**
 102  * Control the RX mode, ie. promiscuous, allmulti, etc...
 103  * All commands require an "out" sg entry containing a 1 byte
 104  * state value, zero = disable, non-zero = enable.  Commands
 105  * 0 and 1 are supported with the VIRTIO_NET_F_CTRL_RX feature.
 106  * Commands 2-5 are added with VIRTIO_NET_F_CTRL_RX_EXTRA.
 107  */
 108 #define VIRTIO_NET_CTRL_RX              0
 109 #define VIRTIO_NET_CTRL_RX_PROMISC      0
 110 #define VIRTIO_NET_CTRL_RX_ALLMULTI     1
 111 #define VIRTIO_NET_CTRL_RX_ALLUNI       2
 112 #define VIRTIO_NET_CTRL_RX_NOMULTI      3
 113 #define VIRTIO_NET_CTRL_RX_NOUNI        4
 114 #define VIRTIO_NET_CTRL_RX_NOBCAST      5
 115
 116 /**
 117  * Control the MAC
 118  *
 119  * The MAC filter table is managed by the hypervisor, the guest should
 120  * assume the size is infinite.  Filtering should be considered
 121  * non-perfect, ie. based on hypervisor resources, the guest may
 122  * received packets from sources not specified in the filter list.
 123  *
 124  * In addition to the class/cmd header, the TABLE_SET command requires
 125  * two out scatterlists.  Each contains a 4 byte count of entries followed
 126  * by a concatenated byte stream of the ETH_ALEN MAC addresses.  The
 127  * first sg list contains unicast addresses, the second is for multicast.
 128  * This functionality is present if the VIRTIO_NET_F_CTRL_RX feature
 129  * is available.
 130  *
 131  * The ADDR_SET command requests one out scatterlist, it contains a
 132  * 6 bytes MAC address. This functionality is present if the
 133  * VIRTIO_NET_F_CTRL_MAC_ADDR feature is available.
 134  */
 135 struct virtio_net_ctrl_mac {
 136         uint32_t entries;
 137         uint8_t macs[][ETHER_ADDR_LEN];
 138 } __attribute__((__packed__));
 139
 140 #define VIRTIO_NET_CTRL_MAC    1
 141 #define VIRTIO_NET_CTRL_MAC_TABLE_SET        0
 142 #define VIRTIO_NET_CTRL_MAC_ADDR_SET         1
 143
 144 /**
 145  * Control VLAN filtering
 146  *
 147  * The VLAN filter table is controlled via a simple ADD/DEL interface.
 148  * VLAN IDs not added may be filtered by the hypervisor.  Del is the
 149  * opposite of add.  Both commands expect an out entry containing a 2
 150  * byte VLAN ID.  VLAN filtering is available with the
 151  * VIRTIO_NET_F_CTRL_VLAN feature bit.
 152  */
 153 #define VIRTIO_NET_CTRL_VLAN     2
 154 #define VIRTIO_NET_CTRL_VLAN_ADD 0
 155 #define VIRTIO_NET_CTRL_VLAN_DEL 1
 156
 157 /*
 158  * Control link announce acknowledgement
 159  *
 160  * The command VIRTIO_NET_CTRL_ANNOUNCE_ACK is used to indicate that
 161  * driver has recevied the notification; device would clear the
 162  * VIRTIO_NET_S_ANNOUNCE bit in the status field after it receives
 163  * this command.
 164  */
 165 #define VIRTIO_NET_CTRL_ANNOUNCE     3
 166 #define VIRTIO_NET_CTRL_ANNOUNCE_ACK 0
 167
 168 struct virtio_net_ctrl_hdr {
 169         uint8_t class;
 170         uint8_t cmd;
 171 } __attribute__((packed));
 172
 173 typedef uint8_t virtio_net_ctrl_ack;
 174
 175 #define VIRTIO_NET_OK     0
 176 #define VIRTIO_NET_ERR    1
 177
 178 #define VIRTIO_MAX_CTRL_DATA 2048
 179
 180 struct virtio_pmd_ctrl {
 181         struct virtio_net_ctrl_hdr hdr;
 182         virtio_net_ctrl_ack status;
 183         uint8_t data[VIRTIO_MAX_CTRL_DATA];
 184 };
 185
 186 struct vq_desc_extra {
 187         void *cookie;
 188         uint16_t ndescs;
 189         uint16_t next;
 190 };
 191
 192 struct virtqueue {
 193         struct virtio_hw  *hw; /**< virtio_hw structure pointer. */
 194         union {
 195                 struct {
 196                         /**< vring keeping desc, used and avail */
 197                         struct vring ring;
 198                 } vq_split;
 199
 200                 struct {
 201                         /**< vring keeping descs and events */
 202                         struct vring_packed ring;
 203                         bool used_wrap_counter;
 204                         uint16_t cached_flags; /**< cached flags for descs */
 205                         uint16_t event_flags_shadow;
 206                 } vq_packed;
 207         };
 208
 209         uint16_t vq_used_cons_idx; /**< last consumed descriptor */
 210         uint16_t vq_nentries;  /**< vring desc numbers */
 211         uint16_t vq_free_cnt;  /**< num of desc available */
 212         uint16_t vq_avail_idx; /**< sync until needed */
 213         uint16_t vq_free_thresh; /**< free threshold */
 214
 215         void *vq_ring_virt_mem;  /**< linear address of vring*/
 216         unsigned int vq_ring_size;
 217
 218         union {
 219                 struct virtnet_rx rxq;
 220                 struct virtnet_tx txq;
 221                 struct virtnet_ctl cq;
 222         };
 223
 224         rte_iova_t vq_ring_mem; /**< physical address of vring,
 225                                  * or virtual address for virtio_user. */
 226
 227         /**
 228          * Head of the free chain in the descriptor table. If
 229          * there are no free descriptors, this will be set to
 230          * VQ_RING_DESC_CHAIN_END.
 231          */
 232         uint16_t  vq_desc_head_idx;
 233         uint16_t  vq_desc_tail_idx;
 234         uint16_t  vq_queue_index;   /**< PCI queue index */
 235         uint16_t offset; /**< relative offset to obtain addr in mbuf */
 236         uint16_t  *notify_addr;
 237         struct rte_mbuf **sw_ring;  /**< RX software ring. */
 238         struct vq_desc_extra vq_descx[0];
 239 };
 240
 241 /* If multiqueue is provided by host, then we suppport it. */
 242 #define VIRTIO_NET_CTRL_MQ   4
 243 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET        0
 244 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN        1
 245 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX        0x8000
 246
 247 /**
 248  * This is the first element of the scatter-gather list.  If you don't
 249  * specify GSO or CSUM features, you can simply ignore the header.
 250  */
 251 struct virtio_net_hdr {
 252 #define VIRTIO_NET_HDR_F_NEEDS_CSUM 1    /**< Use csum_start,csum_offset*/
 253 #define VIRTIO_NET_HDR_F_DATA_VALID 2    /**< Checksum is valid */
 254         uint8_t flags;
 255 #define VIRTIO_NET_HDR_GSO_NONE     0    /**< Not a GSO frame */
 256 #define VIRTIO_NET_HDR_GSO_TCPV4    1    /**< GSO frame, IPv4 TCP (TSO) */
 257 #define VIRTIO_NET_HDR_GSO_UDP      3    /**< GSO frame, IPv4 UDP (UFO) */
 258 #define VIRTIO_NET_HDR_GSO_TCPV6    4    /**< GSO frame, IPv6 TCP */
 259 #define VIRTIO_NET_HDR_GSO_ECN      0x80 /**< TCP has ECN set */
 260         uint8_t gso_type;
 261         uint16_t hdr_len;     /**< Ethernet + IP + tcp/udp hdrs */
 262         uint16_t gso_size;    /**< Bytes to append to hdr_len per frame */
 263         uint16_t csum_start;  /**< Position to start checksumming from */
 264         uint16_t csum_offset; /**< Offset after that to place checksum */
 265 };
 266
 267 /**
 268  * This is the version of the header to use when the MRG_RXBUF
 269  * feature has been negotiated.
 270  */
 271 struct virtio_net_hdr_mrg_rxbuf {
 272         struct   virtio_net_hdr hdr;
 273         uint16_t num_buffers; /**< Number of merged rx buffers */
 274 };
 275
 276 /* Region reserved to allow for transmit header and indirect ring */
 277 #define VIRTIO_MAX_TX_INDIRECT 8
 278 struct virtio_tx_region {
 279         struct virtio_net_hdr_mrg_rxbuf tx_hdr;
 280         struct vring_desc tx_indir[VIRTIO_MAX_TX_INDIRECT]
 281                 __attribute__((__aligned__(16)));
 282 };
 283
 284 static inline int
 285 desc_is_used(struct vring_packed_desc *desc, struct virtqueue *vq)
 286 {
 287         uint16_t used, avail, flags;
 288
 289         flags = desc->flags;
 290         used = !!(flags & VRING_PACKED_DESC_F_USED);
 291         avail = !!(flags & VRING_PACKED_DESC_F_AVAIL);
 292
 293         return avail == used && used == vq->vq_packed.used_wrap_counter;
 294 }
 295
 296 static inline void
 297 vring_desc_init_packed(struct virtqueue *vq, int n)
 298 {
 299         int i;
 300         for (i = 0; i < n - 1; i++) {
 301                 vq->vq_packed.ring.desc[i].id = i;
 302                 vq->vq_descx[i].next = i + 1;
 303         }
 304         vq->vq_packed.ring.desc[i].id = i;
 305         vq->vq_descx[i].next = VQ_RING_DESC_CHAIN_END;
 306 }
 307
 308 /* Chain all the descriptors in the ring with an END */
 309 static inline void
 310 vring_desc_init_split(struct vring_desc *dp, uint16_t n)
 311 {
 312         uint16_t i;
 313
 314         for (i = 0; i < n - 1; i++)
 315                 dp[i].next = (uint16_t)(i + 1);
 316         dp[i].next = VQ_RING_DESC_CHAIN_END;
 317 }
 318
 319 /**
 320  * Tell the backend not to interrupt us. Implementation for packed virtqueues.
 321  */
 322 static inline void
 323 virtqueue_disable_intr_packed(struct virtqueue *vq)
 324 {
 325         if (vq->vq_packed.event_flags_shadow != RING_EVENT_FLAGS_DISABLE) {
 326                 vq->vq_packed.event_flags_shadow = RING_EVENT_FLAGS_DISABLE;
 327                 vq->vq_packed.ring.driver->desc_event_flags =
 328                         vq->vq_packed.event_flags_shadow;
 329         }
 330 }
 331
 332 /**
 333  * Tell the backend not to interrupt us. Implementation for split virtqueues.
 334  */
 335 static inline void
 336 virtqueue_disable_intr_split(struct virtqueue *vq)
 337 {
 338         vq->vq_split.ring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
 339 }
 340
 341 /**
 342  * Tell the backend not to interrupt us.
 343  */
 344 static inline void
 345 virtqueue_disable_intr(struct virtqueue *vq)
 346 {
 347         if (vtpci_packed_queue(vq->hw))
 348                 virtqueue_disable_intr_packed(vq);
 349         else
 350                 virtqueue_disable_intr_split(vq);
 351 }
 352
 353 /**
 354  * Tell the backend to interrupt. Implementation for packed virtqueues.
 355  */
 356 static inline void
 357 virtqueue_enable_intr_packed(struct virtqueue *vq)
 358 {
 359         if (vq->vq_packed.event_flags_shadow == RING_EVENT_FLAGS_DISABLE) {
 360                 vq->vq_packed.event_flags_shadow = RING_EVENT_FLAGS_ENABLE;
 361                 vq->vq_packed.ring.driver->desc_event_flags =
 362                         vq->vq_packed.event_flags_shadow;
 363         }
 364 }
 365
 366 /**
 367  * Tell the backend to interrupt. Implementation for split virtqueues.
 368  */
 369 static inline void
 370 virtqueue_enable_intr_split(struct virtqueue *vq)
 371 {
 372         vq->vq_split.ring.avail->flags &= (~VRING_AVAIL_F_NO_INTERRUPT);
 373 }
 374
 375 /**
 376  * Tell the backend to interrupt us.
 377  */
 378 static inline void
 379 virtqueue_enable_intr(struct virtqueue *vq)
 380 {
 381         if (vtpci_packed_queue(vq->hw))
 382                 virtqueue_enable_intr_packed(vq);
 383         else
 384                 virtqueue_enable_intr_split(vq);
 385 }
 386
 387 /**
 388  *  Dump virtqueue internal structures, for debug purpose only.
 389  */
 390 void virtqueue_dump(struct virtqueue *vq);
 391 /**
 392  *  Get all mbufs to be freed.
 393  */
 394 struct rte_mbuf *virtqueue_detach_unused(struct virtqueue *vq);
 395
 396 /* Flush the elements in the used ring. */
 397 void virtqueue_rxvq_flush(struct virtqueue *vq);
 398
 399 static inline int
 400 virtqueue_full(const struct virtqueue *vq)
 401 {
 402         return vq->vq_free_cnt == 0;
 403 }
 404
 405 static inline int
 406 virtio_get_queue_type(struct virtio_hw *hw, uint16_t vtpci_queue_idx)
 407 {
 408         if (vtpci_queue_idx == hw->max_queue_pairs * 2)
 409                 return VTNET_CQ;
 410         else if (vtpci_queue_idx % 2 == 0)
 411                 return VTNET_RQ;
 412         else
 413                 return VTNET_TQ;
 414 }
 415
 416 #define VIRTQUEUE_NUSED(vq) ((uint16_t)((vq)->vq_split.ring.used->idx - \
 417                                         (vq)->vq_used_cons_idx))
 418
 419 void vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx);
 420 void vq_ring_free_chain_packed(struct virtqueue *vq, uint16_t used_idx);
 421 void vq_ring_free_inorder(struct virtqueue *vq, uint16_t desc_idx,
 422                           uint16_t num);
 423
 424 static inline void
 425 vq_update_avail_idx(struct virtqueue *vq)
 426 {
 427         virtio_wmb(vq->hw->weak_barriers);
 428         vq->vq_split.ring.avail->idx = vq->vq_avail_idx;
 429 }
 430
 431 static inline void
 432 vq_update_avail_ring(struct virtqueue *vq, uint16_t desc_idx)
 433 {
 434         uint16_t avail_idx;
 435         /*
 436          * Place the head of the descriptor chain into the next slot and make
 437          * it usable to the host. The chain is made available now rather than
 438          * deferring to virtqueue_notify() in the hopes that if the host is
 439          * currently running on another CPU, we can keep it processing the new
 440          * descriptor.
 441          */
 442         avail_idx = (uint16_t)(vq->vq_avail_idx & (vq->vq_nentries - 1));
 443         if (unlikely(vq->vq_split.ring.avail->ring[avail_idx] != desc_idx))
 444                 vq->vq_split.ring.avail->ring[avail_idx] = desc_idx;
 445         vq->vq_avail_idx++;
 446 }
 447
 448 static inline int
 449 virtqueue_kick_prepare(struct virtqueue *vq)
 450 {
 451         /*
 452          * Ensure updated avail->idx is visible to vhost before reading
 453          * the used->flags.
 454          */
 455         virtio_mb(vq->hw->weak_barriers);
 456         return !(vq->vq_split.ring.used->flags & VRING_USED_F_NO_NOTIFY);
 457 }
 458
 459 static inline int
 460 virtqueue_kick_prepare_packed(struct virtqueue *vq)
 461 {
 462         uint16_t flags;
 463
 464         /*
 465          * Ensure updated data is visible to vhost before reading the flags.
 466          */
 467         virtio_mb(vq->hw->weak_barriers);
 468         flags = vq->vq_packed.ring.device->desc_event_flags;
 469
 470         return flags != RING_EVENT_FLAGS_DISABLE;
 471 }
 472
 473 /*
 474  * virtqueue_kick_prepare*() or the virtio_wmb() should be called
 475  * before this function to be sure that all the data is visible to vhost.
 476  */
 477 static inline void
 478 virtqueue_notify(struct virtqueue *vq)
 479 {
 480         VTPCI_OPS(vq->hw)->notify_queue(vq->hw, vq);
 481 }
 482
 483 #ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
 484 #define VIRTQUEUE_DUMP(vq) do { \
 485         uint16_t used_idx, nused; \
 486         used_idx = (vq)->vq_split.ring.used->idx; \
 487         nused = (uint16_t)(used_idx - (vq)->vq_used_cons_idx); \
 488         if (vtpci_packed_queue((vq)->hw)) { \
 489                 PMD_INIT_LOG(DEBUG, \
 490                 "VQ: - size=%d; free=%d; used_cons_idx=%d; avail_idx=%d;" \
 491                 " cached_flags=0x%x; used_wrap_counter=%d", \
 492                 (vq)->vq_nentries, (vq)->vq_free_cnt, (vq)->vq_used_cons_idx, \
 493                 (vq)->vq_avail_idx, (vq)->vq_packed.cached_flags, \
 494                 (vq)->vq_packed.used_wrap_counter); \
 495                 break; \
 496         } \
 497         PMD_INIT_LOG(DEBUG, \
 498           "VQ: - size=%d; free=%d; used=%d; desc_head_idx=%d;" \
 499           " avail.idx=%d; used_cons_idx=%d; used.idx=%d;" \
 500           " avail.flags=0x%x; used.flags=0x%x", \
 501           (vq)->vq_nentries, (vq)->vq_free_cnt, nused, \
 502           (vq)->vq_desc_head_idx, (vq)->vq_split.ring.avail->idx, \
 503           (vq)->vq_used_cons_idx, (vq)->vq_split.ring.used->idx, \
 504           (vq)->vq_split.ring.avail->flags, (vq)->vq_split.ring.used->flags); \
 505 } while (0)
 506 #else
 507 #define VIRTQUEUE_DUMP(vq) do { } while (0)
 508 #endif
 509
 510 #endif /* _VIRTQUEUE_H_ */