hw/virtio/vhost-user.c

   1 /*
   2  * vhost-user
   3  *
   4  * Copyright (c) 2013 Virtual Open Systems Sarl.
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  *
   9  */
  10
  11 #include "qemu/osdep.h"
  12 #include "qapi/error.h"
  13 #include "hw/virtio/vhost.h"
  14 #include "hw/virtio/vhost-user.h"
  15 #include "hw/virtio/vhost-backend.h"
  16 #include "hw/virtio/virtio.h"
  17 #include "hw/virtio/virtio-net.h"
  18 #include "chardev/char-fe.h"
  19 #include "sysemu/kvm.h"
  20 #include "qemu/error-report.h"
  21 #include "qemu/sockets.h"
  22 #include "sysemu/cryptodev.h"
  23 #include "migration/migration.h"
  24 #include "migration/postcopy-ram.h"
  25 #include "trace.h"
  26
  27 #include <sys/ioctl.h>
  28 #include <sys/socket.h>
  29 #include <sys/un.h>
  30 #include <linux/vhost.h>
  31 #include <linux/userfaultfd.h>
  32
  33 #define VHOST_MEMORY_MAX_NREGIONS    8
  34 #define VHOST_USER_F_PROTOCOL_FEATURES 30
  35 #define VHOST_USER_SLAVE_MAX_FDS     8
  36
  37 /*
  38  * Maximum size of virtio device config space
  39  */
  40 #define VHOST_USER_MAX_CONFIG_SIZE 256
  41
  42 enum VhostUserProtocolFeature {
  43     VHOST_USER_PROTOCOL_F_MQ = 0,
  44     VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
  45     VHOST_USER_PROTOCOL_F_RARP = 2,
  46     VHOST_USER_PROTOCOL_F_REPLY_ACK = 3,
  47     VHOST_USER_PROTOCOL_F_NET_MTU = 4,
  48     VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5,
  49     VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
  50     VHOST_USER_PROTOCOL_F_CRYPTO_SESSION = 7,
  51     VHOST_USER_PROTOCOL_F_PAGEFAULT = 8,
  52     VHOST_USER_PROTOCOL_F_CONFIG = 9,
  53     VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10,
  54     VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11,
  55     VHOST_USER_PROTOCOL_F_MAX
  56 };
  57
  58 #define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
  59
  60 typedef enum VhostUserRequest {
  61     VHOST_USER_NONE = 0,
  62     VHOST_USER_GET_FEATURES = 1,
  63     VHOST_USER_SET_FEATURES = 2,
  64     VHOST_USER_SET_OWNER = 3,
  65     VHOST_USER_RESET_OWNER = 4,
  66     VHOST_USER_SET_MEM_TABLE = 5,
  67     VHOST_USER_SET_LOG_BASE = 6,
  68     VHOST_USER_SET_LOG_FD = 7,
  69     VHOST_USER_SET_VRING_NUM = 8,
  70     VHOST_USER_SET_VRING_ADDR = 9,
  71     VHOST_USER_SET_VRING_BASE = 10,
  72     VHOST_USER_GET_VRING_BASE = 11,
  73     VHOST_USER_SET_VRING_KICK = 12,
  74     VHOST_USER_SET_VRING_CALL = 13,
  75     VHOST_USER_SET_VRING_ERR = 14,
  76     VHOST_USER_GET_PROTOCOL_FEATURES = 15,
  77     VHOST_USER_SET_PROTOCOL_FEATURES = 16,
  78     VHOST_USER_GET_QUEUE_NUM = 17,
  79     VHOST_USER_SET_VRING_ENABLE = 18,
  80     VHOST_USER_SEND_RARP = 19,
  81     VHOST_USER_NET_SET_MTU = 20,
  82     VHOST_USER_SET_SLAVE_REQ_FD = 21,
  83     VHOST_USER_IOTLB_MSG = 22,
  84     VHOST_USER_SET_VRING_ENDIAN = 23,
  85     VHOST_USER_GET_CONFIG = 24,
  86     VHOST_USER_SET_CONFIG = 25,
  87     VHOST_USER_CREATE_CRYPTO_SESSION = 26,
  88     VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
  89     VHOST_USER_POSTCOPY_ADVISE  = 28,
  90     VHOST_USER_POSTCOPY_LISTEN  = 29,
  91     VHOST_USER_POSTCOPY_END     = 30,
  92     VHOST_USER_MAX
  93 } VhostUserRequest;
  94
  95 typedef enum VhostUserSlaveRequest {
  96     VHOST_USER_SLAVE_NONE = 0,
  97     VHOST_USER_SLAVE_IOTLB_MSG = 1,
  98     VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
  99     VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3,
 100     VHOST_USER_SLAVE_MAX
 101 }  VhostUserSlaveRequest;
 102
 103 typedef struct VhostUserMemoryRegion {
 104     uint64_t guest_phys_addr;
 105     uint64_t memory_size;
 106     uint64_t userspace_addr;
 107     uint64_t mmap_offset;
 108 } VhostUserMemoryRegion;
 109
 110 typedef struct VhostUserMemory {
 111     uint32_t nregions;
 112     uint32_t padding;
 113     VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
 114 } VhostUserMemory;
 115
 116 typedef struct VhostUserLog {
 117     uint64_t mmap_size;
 118     uint64_t mmap_offset;
 119 } VhostUserLog;
 120
 121 typedef struct VhostUserConfig {
 122     uint32_t offset;
 123     uint32_t size;
 124     uint32_t flags;
 125     uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
 126 } VhostUserConfig;
 127
 128 #define VHOST_CRYPTO_SYM_HMAC_MAX_KEY_LEN    512
 129 #define VHOST_CRYPTO_SYM_CIPHER_MAX_KEY_LEN  64
 130
 131 typedef struct VhostUserCryptoSession {
 132     /* session id for success, -1 on errors */
 133     int64_t session_id;
 134     CryptoDevBackendSymSessionInfo session_setup_data;
 135     uint8_t key[VHOST_CRYPTO_SYM_CIPHER_MAX_KEY_LEN];
 136     uint8_t auth_key[VHOST_CRYPTO_SYM_HMAC_MAX_KEY_LEN];
 137 } VhostUserCryptoSession;
 138
 139 static VhostUserConfig c __attribute__ ((unused));
 140 #define VHOST_USER_CONFIG_HDR_SIZE (sizeof(c.offset) \
 141                                    + sizeof(c.size) \
 142                                    + sizeof(c.flags))
 143
 144 typedef struct VhostUserVringArea {
 145     uint64_t u64;
 146     uint64_t size;
 147     uint64_t offset;
 148 } VhostUserVringArea;
 149
 150 typedef struct {
 151     VhostUserRequest request;
 152
 153 #define VHOST_USER_VERSION_MASK     (0x3)
 154 #define VHOST_USER_REPLY_MASK       (0x1<<2)
 155 #define VHOST_USER_NEED_REPLY_MASK  (0x1 << 3)
 156     uint32_t flags;
 157     uint32_t size; /* the following payload size */
 158 } QEMU_PACKED VhostUserHeader;
 159
 160 typedef union {
 161 #define VHOST_USER_VRING_IDX_MASK   (0xff)
 162 #define VHOST_USER_VRING_NOFD_MASK  (0x1<<8)
 163         uint64_t u64;
 164         struct vhost_vring_state state;
 165         struct vhost_vring_addr addr;
 166         VhostUserMemory memory;
 167         VhostUserLog log;
 168         struct vhost_iotlb_msg iotlb;
 169         VhostUserConfig config;
 170         VhostUserCryptoSession session;
 171         VhostUserVringArea area;
 172 } VhostUserPayload;
 173
 174 typedef struct VhostUserMsg {
 175     VhostUserHeader hdr;
 176     VhostUserPayload payload;
 177 } QEMU_PACKED VhostUserMsg;
 178
 179 static VhostUserMsg m __attribute__ ((unused));
 180 #define VHOST_USER_HDR_SIZE (sizeof(VhostUserHeader))
 181
 182 #define VHOST_USER_PAYLOAD_SIZE (sizeof(VhostUserPayload))
 183
 184 /* The version of the protocol we support */
 185 #define VHOST_USER_VERSION    (0x1)
 186
 187 struct vhost_user {
 188     struct vhost_dev *dev;
 189     /* Shared between vhost devs of the same virtio device */
 190     VhostUserState *user;
 191     int slave_fd;
 192     NotifierWithReturn postcopy_notifier;
 193     struct PostCopyFD  postcopy_fd;
 194     uint64_t           postcopy_client_bases[VHOST_MEMORY_MAX_NREGIONS];
 195     /* Length of the region_rb and region_rb_offset arrays */
 196     size_t             region_rb_len;
 197     /* RAMBlock associated with a given region */
 198     RAMBlock         **region_rb;
 199     /* The offset from the start of the RAMBlock to the start of the
 200      * vhost region.
 201      */
 202     ram_addr_t        *region_rb_offset;
 203
 204     /* True once we've entered postcopy_listen */
 205     bool               postcopy_listen;
 206 };
 207
 208 static bool ioeventfd_enabled(void)
 209 {
 210     return !kvm_enabled() || kvm_eventfds_enabled();
 211 }
 212
 213 static int vhost_user_read(struct vhost_dev *dev, VhostUserMsg *msg)
 214 {
 215     struct vhost_user *u = dev->opaque;
 216     CharBackend *chr = u->user->chr;
 217     uint8_t *p = (uint8_t *) msg;
 218     int r, size = VHOST_USER_HDR_SIZE;
 219
 220     r = qemu_chr_fe_read_all(chr, p, size);
 221     if (r != size) {
 222         error_report("Failed to read msg header. Read %d instead of %d."
 223                      " Original request %d.", r, size, msg->hdr.request);
 224         goto fail;
 225     }
 226
 227     /* validate received flags */
 228     if (msg->hdr.flags != (VHOST_USER_REPLY_MASK | VHOST_USER_VERSION)) {
 229         error_report("Failed to read msg header."
 230                 " Flags 0x%x instead of 0x%x.", msg->hdr.flags,
 231                 VHOST_USER_REPLY_MASK | VHOST_USER_VERSION);
 232         goto fail;
 233     }
 234
 235     /* validate message size is sane */
 236     if (msg->hdr.size > VHOST_USER_PAYLOAD_SIZE) {
 237         error_report("Failed to read msg header."
 238                 " Size %d exceeds the maximum %zu.", msg->hdr.size,
 239                 VHOST_USER_PAYLOAD_SIZE);
 240         goto fail;
 241     }
 242
 243     if (msg->hdr.size) {
 244         p += VHOST_USER_HDR_SIZE;
 245         size = msg->hdr.size;
 246         r = qemu_chr_fe_read_all(chr, p, size);
 247         if (r != size) {
 248             error_report("Failed to read msg payload."
 249                          " Read %d instead of %d.", r, msg->hdr.size);
 250             goto fail;
 251         }
 252     }
 253
 254     return 0;
 255
 256 fail:
 257     return -1;
 258 }
 259
 260 static int process_message_reply(struct vhost_dev *dev,
 261                                  const VhostUserMsg *msg)
 262 {
 263     VhostUserMsg msg_reply;
 264
 265     if ((msg->hdr.flags & VHOST_USER_NEED_REPLY_MASK) == 0) {
 266         return 0;
 267     }
 268
 269     if (vhost_user_read(dev, &msg_reply) < 0) {
 270         return -1;
 271     }
 272
 273     if (msg_reply.hdr.request != msg->hdr.request) {
 274         error_report("Received unexpected msg type."
 275                      "Expected %d received %d",
 276                      msg->hdr.request, msg_reply.hdr.request);
 277         return -1;
 278     }
 279
 280     return msg_reply.payload.u64 ? -1 : 0;
 281 }
 282
 283 static bool vhost_user_one_time_request(VhostUserRequest request)
 284 {
 285     switch (request) {
 286     case VHOST_USER_SET_OWNER:
 287     case VHOST_USER_RESET_OWNER:
 288     case VHOST_USER_SET_MEM_TABLE:
 289     case VHOST_USER_GET_QUEUE_NUM:
 290     case VHOST_USER_NET_SET_MTU:
 291         return true;
 292     default:
 293         return false;
 294     }
 295 }
 296
 297 /* most non-init callers ignore the error */
 298 static int vhost_user_write(struct vhost_dev *dev, VhostUserMsg *msg,
 299                             int *fds, int fd_num)
 300 {
 301     struct vhost_user *u = dev->opaque;
 302     CharBackend *chr = u->user->chr;
 303     int ret, size = VHOST_USER_HDR_SIZE + msg->hdr.size;
 304
 305     /*
 306      * For non-vring specific requests, like VHOST_USER_SET_MEM_TABLE,
 307      * we just need send it once in the first time. For later such
 308      * request, we just ignore it.
 309      */
 310     if (vhost_user_one_time_request(msg->hdr.request) && dev->vq_index != 0) {
 311         msg->hdr.flags &= ~VHOST_USER_NEED_REPLY_MASK;
 312         return 0;
 313     }
 314
 315     if (qemu_chr_fe_set_msgfds(chr, fds, fd_num) < 0) {
 316         error_report("Failed to set msg fds.");
 317         return -1;
 318     }
 319
 320     ret = qemu_chr_fe_write_all(chr, (const uint8_t *) msg, size);
 321     if (ret != size) {
 322         error_report("Failed to write msg."
 323                      " Wrote %d instead of %d.", ret, size);
 324         return -1;
 325     }
 326
 327     return 0;
 328 }
 329
 330 static int vhost_user_set_log_base(struct vhost_dev *dev, uint64_t base,
 331                                    struct vhost_log *log)
 332 {
 333     int fds[VHOST_MEMORY_MAX_NREGIONS];
 334     size_t fd_num = 0;
 335     bool shmfd = virtio_has_feature(dev->protocol_features,
 336                                     VHOST_USER_PROTOCOL_F_LOG_SHMFD);
 337     VhostUserMsg msg = {
 338         .hdr.request = VHOST_USER_SET_LOG_BASE,
 339         .hdr.flags = VHOST_USER_VERSION,
 340         .payload.log.mmap_size = log->size * sizeof(*(log->log)),
 341         .payload.log.mmap_offset = 0,
 342         .hdr.size = sizeof(msg.payload.log),
 343     };
 344
 345     if (shmfd && log->fd != -1) {
 346         fds[fd_num++] = log->fd;
 347     }
 348
 349     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
 350         return -1;
 351     }
 352
 353     if (shmfd) {
 354         msg.hdr.size = 0;
 355         if (vhost_user_read(dev, &msg) < 0) {
 356             return -1;
 357         }
 358
 359         if (msg.hdr.request != VHOST_USER_SET_LOG_BASE) {
 360             error_report("Received unexpected msg type. "
 361                          "Expected %d received %d",
 362                          VHOST_USER_SET_LOG_BASE, msg.hdr.request);
 363             return -1;
 364         }
 365     }
 366
 367     return 0;
 368 }
 369
 370 static int vhost_user_set_mem_table_postcopy(struct vhost_dev *dev,
 371                                              struct vhost_memory *mem)
 372 {
 373     struct vhost_user *u = dev->opaque;
 374     int fds[VHOST_MEMORY_MAX_NREGIONS];
 375     int i, fd;
 376     size_t fd_num = 0;
 377     VhostUserMsg msg_reply;
 378     int region_i, msg_i;
 379
 380     VhostUserMsg msg = {
 381         .hdr.request = VHOST_USER_SET_MEM_TABLE,
 382         .hdr.flags = VHOST_USER_VERSION,
 383     };
 384
 385     if (u->region_rb_len < dev->mem->nregions) {
 386         u->region_rb = g_renew(RAMBlock*, u->region_rb, dev->mem->nregions);
 387         u->region_rb_offset = g_renew(ram_addr_t, u->region_rb_offset,
 388                                       dev->mem->nregions);
 389         memset(&(u->region_rb[u->region_rb_len]), '\0',
 390                sizeof(RAMBlock *) * (dev->mem->nregions - u->region_rb_len));
 391         memset(&(u->region_rb_offset[u->region_rb_len]), '\0',
 392                sizeof(ram_addr_t) * (dev->mem->nregions - u->region_rb_len));
 393         u->region_rb_len = dev->mem->nregions;
 394     }
 395
 396     for (i = 0; i < dev->mem->nregions; ++i) {
 397         struct vhost_memory_region *reg = dev->mem->regions + i;
 398         ram_addr_t offset;
 399         MemoryRegion *mr;
 400
 401         assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
 402         mr = memory_region_from_host((void *)(uintptr_t)reg->userspace_addr,
 403                                      &offset);
 404         fd = memory_region_get_fd(mr);
 405         if (fd > 0) {
 406             trace_vhost_user_set_mem_table_withfd(fd_num, mr->name,
 407                                                   reg->memory_size,
 408                                                   reg->guest_phys_addr,
 409                                                   reg->userspace_addr, offset);
 410             u->region_rb_offset[i] = offset;
 411             u->region_rb[i] = mr->ram_block;
 412             msg.payload.memory.regions[fd_num].userspace_addr =
 413                 reg->userspace_addr;
 414             msg.payload.memory.regions[fd_num].memory_size  = reg->memory_size;
 415             msg.payload.memory.regions[fd_num].guest_phys_addr =
 416                 reg->guest_phys_addr;
 417             msg.payload.memory.regions[fd_num].mmap_offset = offset;
 418             assert(fd_num < VHOST_MEMORY_MAX_NREGIONS);
 419             fds[fd_num++] = fd;
 420         } else {
 421             u->region_rb_offset[i] = 0;
 422             u->region_rb[i] = NULL;
 423         }
 424     }
 425
 426     msg.payload.memory.nregions = fd_num;
 427
 428     if (!fd_num) {
 429         error_report("Failed initializing vhost-user memory map, "
 430                      "consider using -object memory-backend-file share=on");
 431         return -1;
 432     }
 433
 434     msg.hdr.size = sizeof(msg.payload.memory.nregions);
 435     msg.hdr.size += sizeof(msg.payload.memory.padding);
 436     msg.hdr.size += fd_num * sizeof(VhostUserMemoryRegion);
 437
 438     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
 439         return -1;
 440     }
 441
 442     if (vhost_user_read(dev, &msg_reply) < 0) {
 443         return -1;
 444     }
 445
 446     if (msg_reply.hdr.request != VHOST_USER_SET_MEM_TABLE) {
 447         error_report("%s: Received unexpected msg type."
 448                      "Expected %d received %d", __func__,
 449                      VHOST_USER_SET_MEM_TABLE, msg_reply.hdr.request);
 450         return -1;
 451     }
 452     /* We're using the same structure, just reusing one of the
 453      * fields, so it should be the same size.
 454      */
 455     if (msg_reply.hdr.size != msg.hdr.size) {
 456         error_report("%s: Unexpected size for postcopy reply "
 457                      "%d vs %d", __func__, msg_reply.hdr.size, msg.hdr.size);
 458         return -1;
 459     }
 460
 461     memset(u->postcopy_client_bases, 0,
 462            sizeof(uint64_t) * VHOST_MEMORY_MAX_NREGIONS);
 463
 464     /* They're in the same order as the regions that were sent
 465      * but some of the regions were skipped (above) if they
 466      * didn't have fd's
 467     */
 468     for (msg_i = 0, region_i = 0;
 469          region_i < dev->mem->nregions;
 470         region_i++) {
 471         if (msg_i < fd_num &&
 472             msg_reply.payload.memory.regions[msg_i].guest_phys_addr ==
 473             dev->mem->regions[region_i].guest_phys_addr) {
 474             u->postcopy_client_bases[region_i] =
 475                 msg_reply.payload.memory.regions[msg_i].userspace_addr;
 476             trace_vhost_user_set_mem_table_postcopy(
 477                 msg_reply.payload.memory.regions[msg_i].userspace_addr,
 478                 msg.payload.memory.regions[msg_i].userspace_addr,
 479                 msg_i, region_i);
 480             msg_i++;
 481         }
 482     }
 483     if (msg_i != fd_num) {
 484         error_report("%s: postcopy reply not fully consumed "
 485                      "%d vs %zd",
 486                      __func__, msg_i, fd_num);
 487         return -1;
 488     }
 489     /* Now we've registered this with the postcopy code, we ack to the client,
 490      * because now we're in the position to be able to deal with any faults
 491      * it generates.
 492      */
 493     /* TODO: Use this for failure cases as well with a bad value */
 494     msg.hdr.size = sizeof(msg.payload.u64);
 495     msg.payload.u64 = 0; /* OK */
 496     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
 497         return -1;
 498     }
 499
 500     return 0;
 501 }
 502
 503 static int vhost_user_set_mem_table(struct vhost_dev *dev,
 504                                     struct vhost_memory *mem)
 505 {
 506     struct vhost_user *u = dev->opaque;
 507     int fds[VHOST_MEMORY_MAX_NREGIONS];
 508     int i, fd;
 509     size_t fd_num = 0;
 510     bool do_postcopy = u->postcopy_listen && u->postcopy_fd.handler;
 511     bool reply_supported = virtio_has_feature(dev->protocol_features,
 512                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
 513
 514     if (do_postcopy) {
 515         /* Postcopy has enough differences that it's best done in it's own
 516          * version
 517          */
 518         return vhost_user_set_mem_table_postcopy(dev, mem);
 519     }
 520
 521     VhostUserMsg msg = {
 522         .hdr.request = VHOST_USER_SET_MEM_TABLE,
 523         .hdr.flags = VHOST_USER_VERSION,
 524     };
 525
 526     if (reply_supported) {
 527         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
 528     }
 529
 530     for (i = 0; i < dev->mem->nregions; ++i) {
 531         struct vhost_memory_region *reg = dev->mem->regions + i;
 532         ram_addr_t offset;
 533         MemoryRegion *mr;
 534
 535         assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
 536         mr = memory_region_from_host((void *)(uintptr_t)reg->userspace_addr,
 537                                      &offset);
 538         fd = memory_region_get_fd(mr);
 539         if (fd > 0) {
 540             if (fd_num == VHOST_MEMORY_MAX_NREGIONS) {
 541                 error_report("Failed preparing vhost-user memory table msg");
 542                 return -1;
 543             }
 544             msg.payload.memory.regions[fd_num].userspace_addr =
 545                 reg->userspace_addr;
 546             msg.payload.memory.regions[fd_num].memory_size  = reg->memory_size;
 547             msg.payload.memory.regions[fd_num].guest_phys_addr =
 548                 reg->guest_phys_addr;
 549             msg.payload.memory.regions[fd_num].mmap_offset = offset;
 550             fds[fd_num++] = fd;
 551         }
 552     }
 553
 554     msg.payload.memory.nregions = fd_num;
 555
 556     if (!fd_num) {
 557         error_report("Failed initializing vhost-user memory map, "
 558                      "consider using -object memory-backend-file share=on");
 559         return -1;
 560     }
 561
 562     msg.hdr.size = sizeof(msg.payload.memory.nregions);
 563     msg.hdr.size += sizeof(msg.payload.memory.padding);
 564     msg.hdr.size += fd_num * sizeof(VhostUserMemoryRegion);
 565
 566     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
 567         return -1;
 568     }
 569
 570     if (reply_supported) {
 571         return process_message_reply(dev, &msg);
 572     }
 573
 574     return 0;
 575 }
 576
 577 static int vhost_user_set_vring_addr(struct vhost_dev *dev,
 578                                      struct vhost_vring_addr *addr)
 579 {
 580     VhostUserMsg msg = {
 581         .hdr.request = VHOST_USER_SET_VRING_ADDR,
 582         .hdr.flags = VHOST_USER_VERSION,
 583         .payload.addr = *addr,
 584         .hdr.size = sizeof(msg.payload.addr),
 585     };
 586
 587     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
 588         return -1;
 589     }
 590
 591     return 0;
 592 }
 593
 594 static int vhost_user_set_vring_endian(struct vhost_dev *dev,
 595                                        struct vhost_vring_state *ring)
 596 {
 597     bool cross_endian = virtio_has_feature(dev->protocol_features,
 598                                            VHOST_USER_PROTOCOL_F_CROSS_ENDIAN);
 599     VhostUserMsg msg = {
 600         .hdr.request = VHOST_USER_SET_VRING_ENDIAN,
 601         .hdr.flags = VHOST_USER_VERSION,
 602         .payload.state = *ring,
 603         .hdr.size = sizeof(msg.payload.state),
 604     };
 605
 606     if (!cross_endian) {
 607         error_report("vhost-user trying to send unhandled ioctl");
 608         return -1;
 609     }
 610
 611     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
 612         return -1;
 613     }
 614
 615     return 0;
 616 }
 617
 618 static int vhost_set_vring(struct vhost_dev *dev,
 619                            unsigned long int request,
 620                            struct vhost_vring_state *ring)
 621 {
 622     VhostUserMsg msg = {
 623         .hdr.request = request,
 624         .hdr.flags = VHOST_USER_VERSION,
 625         .payload.state = *ring,
 626         .hdr.size = sizeof(msg.payload.state),
 627     };
 628
 629     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
 630         return -1;
 631     }
 632
 633     return 0;
 634 }
 635
 636 static int vhost_user_set_vring_num(struct vhost_dev *dev,
 637                                     struct vhost_vring_state *ring)
 638 {
 639     return vhost_set_vring(dev, VHOST_USER_SET_VRING_NUM, ring);
 640 }
 641
 642 static void vhost_user_host_notifier_restore(struct vhost_dev *dev,
 643                                              int queue_idx)
 644 {
 645     struct vhost_user *u = dev->opaque;
 646     VhostUserHostNotifier *n = &u->user->notifier[queue_idx];
 647     VirtIODevice *vdev = dev->vdev;
 648
 649     if (n->addr && !n->set) {
 650         virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, true);
 651         n->set = true;
 652     }
 653 }
 654
 655 static void vhost_user_host_notifier_remove(struct vhost_dev *dev,
 656                                             int queue_idx)
 657 {
 658     struct vhost_user *u = dev->opaque;
 659     VhostUserHostNotifier *n = &u->user->notifier[queue_idx];
 660     VirtIODevice *vdev = dev->vdev;
 661
 662     if (n->addr && n->set) {
 663         virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, false);
 664         n->set = false;
 665     }
 666 }
 667
 668 static int vhost_user_set_vring_base(struct vhost_dev *dev,
 669                                      struct vhost_vring_state *ring)
 670 {
 671     vhost_user_host_notifier_restore(dev, ring->index);
 672
 673     return vhost_set_vring(dev, VHOST_USER_SET_VRING_BASE, ring);
 674 }
 675
 676 static int vhost_user_set_vring_enable(struct vhost_dev *dev, int enable)
 677 {
 678     int i;
 679
 680     if (!virtio_has_feature(dev->features, VHOST_USER_F_PROTOCOL_FEATURES)) {
 681         return -1;
 682     }
 683
 684     for (i = 0; i < dev->nvqs; ++i) {
 685         struct vhost_vring_state state = {
 686             .index = dev->vq_index + i,
 687             .num   = enable,
 688         };
 689
 690         vhost_set_vring(dev, VHOST_USER_SET_VRING_ENABLE, &state);
 691     }
 692
 693     return 0;
 694 }
 695
 696 static int vhost_user_get_vring_base(struct vhost_dev *dev,
 697                                      struct vhost_vring_state *ring)
 698 {
 699     VhostUserMsg msg = {
 700         .hdr.request = VHOST_USER_GET_VRING_BASE,
 701         .hdr.flags = VHOST_USER_VERSION,
 702         .payload.state = *ring,
 703         .hdr.size = sizeof(msg.payload.state),
 704     };
 705
 706     vhost_user_host_notifier_remove(dev, ring->index);
 707
 708     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
 709         return -1;
 710     }
 711
 712     if (vhost_user_read(dev, &msg) < 0) {
 713         return -1;
 714     }
 715
 716     if (msg.hdr.request != VHOST_USER_GET_VRING_BASE) {
 717         error_report("Received unexpected msg type. Expected %d received %d",
 718                      VHOST_USER_GET_VRING_BASE, msg.hdr.request);
 719         return -1;
 720     }
 721
 722     if (msg.hdr.size != sizeof(msg.payload.state)) {
 723         error_report("Received bad msg size.");
 724         return -1;
 725     }
 726
 727     *ring = msg.payload.state;
 728
 729     return 0;
 730 }
 731
 732 static int vhost_set_vring_file(struct vhost_dev *dev,
 733                                 VhostUserRequest request,
 734                                 struct vhost_vring_file *file)
 735 {
 736     int fds[VHOST_MEMORY_MAX_NREGIONS];
 737     size_t fd_num = 0;
 738     VhostUserMsg msg = {
 739         .hdr.request = request,
 740         .hdr.flags = VHOST_USER_VERSION,
 741         .payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK,
 742         .hdr.size = sizeof(msg.payload.u64),
 743     };
 744
 745     if (ioeventfd_enabled() && file->fd > 0) {
 746         fds[fd_num++] = file->fd;
 747     } else {
 748         msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
 749     }
 750
 751     if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
 752         return -1;
 753     }
 754
 755     return 0;
 756 }
 757
 758 static int vhost_user_set_vring_kick(struct vhost_dev *dev,
 759                                      struct vhost_vring_file *file)
 760 {
 761     return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_KICK, file);
 762 }
 763
 764 static int vhost_user_set_vring_call(struct vhost_dev *dev,
 765                                      struct vhost_vring_file *file)
 766 {
 767     return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_CALL, file);
 768 }
 769
 770 static int vhost_user_set_u64(struct vhost_dev *dev, int request, uint64_t u64)
 771 {
 772     VhostUserMsg msg = {
 773         .hdr.request = request,
 774         .hdr.flags = VHOST_USER_VERSION,
 775         .payload.u64 = u64,
 776         .hdr.size = sizeof(msg.payload.u64),
 777     };
 778
 779     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
 780         return -1;
 781     }
 782
 783     return 0;
 784 }
 785
 786 static int vhost_user_set_features(struct vhost_dev *dev,
 787                                    uint64_t features)
 788 {
 789     return vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES, features);
 790 }
 791
 792 static int vhost_user_set_protocol_features(struct vhost_dev *dev,
 793                                             uint64_t features)
 794 {
 795     return vhost_user_set_u64(dev, VHOST_USER_SET_PROTOCOL_FEATURES, features);
 796 }
 797
 798 static int vhost_user_get_u64(struct vhost_dev *dev, int request, uint64_t *u64)
 799 {
 800     VhostUserMsg msg = {
 801         .hdr.request = request,
 802         .hdr.flags = VHOST_USER_VERSION,
 803     };
 804
 805     if (vhost_user_one_time_request(request) && dev->vq_index != 0) {
 806         return 0;
 807     }
 808
 809     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
 810         return -1;
 811     }
 812
 813     if (vhost_user_read(dev, &msg) < 0) {
 814         return -1;
 815     }
 816
 817     if (msg.hdr.request != request) {
 818         error_report("Received unexpected msg type. Expected %d received %d",
 819                      request, msg.hdr.request);
 820         return -1;
 821     }
 822
 823     if (msg.hdr.size != sizeof(msg.payload.u64)) {
 824         error_report("Received bad msg size.");
 825         return -1;
 826     }
 827
 828     *u64 = msg.payload.u64;
 829
 830     return 0;
 831 }
 832
 833 static int vhost_user_get_features(struct vhost_dev *dev, uint64_t *features)
 834 {
 835     return vhost_user_get_u64(dev, VHOST_USER_GET_FEATURES, features);
 836 }
 837
 838 static int vhost_user_set_owner(struct vhost_dev *dev)
 839 {
 840     VhostUserMsg msg = {
 841         .hdr.request = VHOST_USER_SET_OWNER,
 842         .hdr.flags = VHOST_USER_VERSION,
 843     };
 844
 845     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
 846         return -1;
 847     }
 848
 849     return 0;
 850 }
 851
 852 static int vhost_user_reset_device(struct vhost_dev *dev)
 853 {
 854     VhostUserMsg msg = {
 855         .hdr.request = VHOST_USER_RESET_OWNER,
 856         .hdr.flags = VHOST_USER_VERSION,
 857     };
 858
 859     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
 860         return -1;
 861     }
 862
 863     return 0;
 864 }
 865
 866 static int vhost_user_slave_handle_config_change(struct vhost_dev *dev)
 867 {
 868     int ret = -1;
 869
 870     if (!dev->config_ops) {
 871         return -1;
 872     }
 873
 874     if (dev->config_ops->vhost_dev_config_notifier) {
 875         ret = dev->config_ops->vhost_dev_config_notifier(dev);
 876     }
 877
 878     return ret;
 879 }
 880
 881 static int vhost_user_slave_handle_vring_host_notifier(struct vhost_dev *dev,
 882                                                        VhostUserVringArea *area,
 883                                                        int fd)
 884 {
 885     int queue_idx = area->u64 & VHOST_USER_VRING_IDX_MASK;
 886     size_t page_size = qemu_real_host_page_size;
 887     struct vhost_user *u = dev->opaque;
 888     VhostUserState *user = u->user;
 889     VirtIODevice *vdev = dev->vdev;
 890     VhostUserHostNotifier *n;
 891     void *addr;
 892     char *name;
 893
 894     if (!virtio_has_feature(dev->protocol_features,
 895                             VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) ||
 896         vdev == NULL || queue_idx >= virtio_get_num_queues(vdev)) {
 897         return -1;
 898     }
 899
 900     n = &user->notifier[queue_idx];
 901
 902     if (n->addr) {
 903         virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, false);
 904         object_unparent(OBJECT(&n->mr));
 905         munmap(n->addr, page_size);
 906         n->addr = NULL;
 907     }
 908
 909     if (area->u64 & VHOST_USER_VRING_NOFD_MASK) {
 910         return 0;
 911     }
 912
 913     /* Sanity check. */
 914     if (area->size != page_size) {
 915         return -1;
 916     }
 917
 918     addr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED,
 919                 fd, area->offset);
 920     if (addr == MAP_FAILED) {
 921         return -1;
 922     }
 923
 924     name = g_strdup_printf("vhost-user/host-notifier@%p mmaps[%d]",
 925                            user, queue_idx);
 926     memory_region_init_ram_device_ptr(&n->mr, OBJECT(vdev), name,
 927                                       page_size, addr);
 928     g_free(name);
 929
 930     if (virtio_queue_set_host_notifier_mr(vdev, queue_idx, &n->mr, true)) {
 931         munmap(addr, page_size);
 932         return -1;
 933     }
 934
 935     n->addr = addr;
 936     n->set = true;
 937
 938     return 0;
 939 }
 940
 941 static void slave_read(void *opaque)
 942 {
 943     struct vhost_dev *dev = opaque;
 944     struct vhost_user *u = dev->opaque;
 945     VhostUserHeader hdr = { 0, };
 946     VhostUserPayload payload = { 0, };
 947     int size, ret = 0;
 948     struct iovec iov;
 949     struct msghdr msgh;
 950     int fd[VHOST_USER_SLAVE_MAX_FDS];
 951     char control[CMSG_SPACE(sizeof(fd))];
 952     struct cmsghdr *cmsg;
 953     int i, fdsize = 0;
 954
 955     memset(&msgh, 0, sizeof(msgh));
 956     msgh.msg_iov = &iov;
 957     msgh.msg_iovlen = 1;
 958     msgh.msg_control = control;
 959     msgh.msg_controllen = sizeof(control);
 960
 961     memset(fd, -1, sizeof(fd));
 962
 963     /* Read header */
 964     iov.iov_base = &hdr;
 965     iov.iov_len = VHOST_USER_HDR_SIZE;
 966
 967     size = recvmsg(u->slave_fd, &msgh, 0);
 968     if (size != VHOST_USER_HDR_SIZE) {
 969         error_report("Failed to read from slave.");
 970         goto err;
 971     }
 972
 973     if (msgh.msg_flags & MSG_CTRUNC) {
 974         error_report("Truncated message.");
 975         goto err;
 976     }
 977
 978     for (cmsg = CMSG_FIRSTHDR(&msgh); cmsg != NULL;
 979          cmsg = CMSG_NXTHDR(&msgh, cmsg)) {
 980             if (cmsg->cmsg_level == SOL_SOCKET &&
 981                 cmsg->cmsg_type == SCM_RIGHTS) {
 982                     fdsize = cmsg->cmsg_len - CMSG_LEN(0);
 983                     memcpy(fd, CMSG_DATA(cmsg), fdsize);
 984                     break;
 985             }
 986     }
 987
 988     if (hdr.size > VHOST_USER_PAYLOAD_SIZE) {
 989         error_report("Failed to read msg header."
 990                 " Size %d exceeds the maximum %zu.", hdr.size,
 991                 VHOST_USER_PAYLOAD_SIZE);
 992         goto err;
 993     }
 994
 995     /* Read payload */
 996     size = read(u->slave_fd, &payload, hdr.size);
 997     if (size != hdr.size) {
 998         error_report("Failed to read payload from slave.");
 999         goto err;
1000     }
1001
1002     switch (hdr.request) {
1003     case VHOST_USER_SLAVE_IOTLB_MSG:
1004         ret = vhost_backend_handle_iotlb_msg(dev, &payload.iotlb);
1005         break;
1006     case VHOST_USER_SLAVE_CONFIG_CHANGE_MSG :
1007         ret = vhost_user_slave_handle_config_change(dev);
1008         break;
1009     case VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG:
1010         ret = vhost_user_slave_handle_vring_host_notifier(dev, &payload.area,
1011                                                           fd[0]);
1012         break;
1013     default:
1014         error_report("Received unexpected msg type.");
1015         ret = -EINVAL;
1016     }
1017
1018     /* Close the remaining file descriptors. */
1019     for (i = 0; i < fdsize; i++) {
1020         if (fd[i] != -1) {
1021             close(fd[i]);
1022         }
1023     }
1024
1025     /*
1026      * REPLY_ACK feature handling. Other reply types has to be managed
1027      * directly in their request handlers.
1028      */
1029     if (hdr.flags & VHOST_USER_NEED_REPLY_MASK) {
1030         struct iovec iovec[2];
1031
1032
1033         hdr.flags &= ~VHOST_USER_NEED_REPLY_MASK;
1034         hdr.flags |= VHOST_USER_REPLY_MASK;
1035
1036         payload.u64 = !!ret;
1037         hdr.size = sizeof(payload.u64);
1038
1039         iovec[0].iov_base = &hdr;
1040         iovec[0].iov_len = VHOST_USER_HDR_SIZE;
1041         iovec[1].iov_base = &payload;
1042         iovec[1].iov_len = hdr.size;
1043
1044         size = writev(u->slave_fd, iovec, ARRAY_SIZE(iovec));
1045         if (size != VHOST_USER_HDR_SIZE + hdr.size) {
1046             error_report("Failed to send msg reply to slave.");
1047             goto err;
1048         }
1049     }
1050
1051     return;
1052
1053 err:
1054     qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
1055     close(u->slave_fd);
1056     u->slave_fd = -1;
1057     for (i = 0; i < fdsize; i++) {
1058         if (fd[i] != -1) {
1059             close(fd[i]);
1060         }
1061     }
1062     return;
1063 }
1064
1065 static int vhost_setup_slave_channel(struct vhost_dev *dev)
1066 {
1067     VhostUserMsg msg = {
1068         .hdr.request = VHOST_USER_SET_SLAVE_REQ_FD,
1069         .hdr.flags = VHOST_USER_VERSION,
1070     };
1071     struct vhost_user *u = dev->opaque;
1072     int sv[2], ret = 0;
1073     bool reply_supported = virtio_has_feature(dev->protocol_features,
1074                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
1075
1076     if (!virtio_has_feature(dev->protocol_features,
1077                             VHOST_USER_PROTOCOL_F_SLAVE_REQ)) {
1078         return 0;
1079     }
1080
1081     if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) {
1082         error_report("socketpair() failed");
1083         return -1;
1084     }
1085
1086     u->slave_fd = sv[0];
1087     qemu_set_fd_handler(u->slave_fd, slave_read, NULL, dev);
1088
1089     if (reply_supported) {
1090         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
1091     }
1092
1093     ret = vhost_user_write(dev, &msg, &sv[1], 1);
1094     if (ret) {
1095         goto out;
1096     }
1097
1098     if (reply_supported) {
1099         ret = process_message_reply(dev, &msg);
1100     }
1101
1102 out:
1103     close(sv[1]);
1104     if (ret) {
1105         qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
1106         close(u->slave_fd);
1107         u->slave_fd = -1;
1108     }
1109
1110     return ret;
1111 }
1112
1113 /*
1114  * Called back from the postcopy fault thread when a fault is received on our
1115  * ufd.
1116  * TODO: This is Linux specific
1117  */
1118 static int vhost_user_postcopy_fault_handler(struct PostCopyFD *pcfd,
1119                                              void *ufd)
1120 {
1121     struct vhost_dev *dev = pcfd->data;
1122     struct vhost_user *u = dev->opaque;
1123     struct uffd_msg *msg = ufd;
1124     uint64_t faultaddr = msg->arg.pagefault.address;
1125     RAMBlock *rb = NULL;
1126     uint64_t rb_offset;
1127     int i;
1128
1129     trace_vhost_user_postcopy_fault_handler(pcfd->idstr, faultaddr,
1130                                             dev->mem->nregions);
1131     for (i = 0; i < MIN(dev->mem->nregions, u->region_rb_len); i++) {
1132         trace_vhost_user_postcopy_fault_handler_loop(i,
1133                 u->postcopy_client_bases[i], dev->mem->regions[i].memory_size);
1134         if (faultaddr >= u->postcopy_client_bases[i]) {
1135             /* Ofset of the fault address in the vhost region */
1136             uint64_t region_offset = faultaddr - u->postcopy_client_bases[i];
1137             if (region_offset < dev->mem->regions[i].memory_size) {
1138                 rb_offset = region_offset + u->region_rb_offset[i];
1139                 trace_vhost_user_postcopy_fault_handler_found(i,
1140                         region_offset, rb_offset);
1141                 rb = u->region_rb[i];
1142                 return postcopy_request_shared_page(pcfd, rb, faultaddr,
1143                                                     rb_offset);
1144             }
1145         }
1146     }
1147     error_report("%s: Failed to find region for fault %" PRIx64,
1148                  __func__, faultaddr);
1149     return -1;
1150 }
1151
1152 static int vhost_user_postcopy_waker(struct PostCopyFD *pcfd, RAMBlock *rb,
1153                                      uint64_t offset)
1154 {
1155     struct vhost_dev *dev = pcfd->data;
1156     struct vhost_user *u = dev->opaque;
1157     int i;
1158
1159     trace_vhost_user_postcopy_waker(qemu_ram_get_idstr(rb), offset);
1160
1161     if (!u) {
1162         return 0;
1163     }
1164     /* Translate the offset into an address in the clients address space */
1165     for (i = 0; i < MIN(dev->mem->nregions, u->region_rb_len); i++) {
1166         if (u->region_rb[i] == rb &&
1167             offset >= u->region_rb_offset[i] &&
1168             offset < (u->region_rb_offset[i] +
1169                       dev->mem->regions[i].memory_size)) {
1170             uint64_t client_addr = (offset - u->region_rb_offset[i]) +
1171                                    u->postcopy_client_bases[i];
1172             trace_vhost_user_postcopy_waker_found(client_addr);
1173             return postcopy_wake_shared(pcfd, client_addr, rb);
1174         }
1175     }
1176
1177     trace_vhost_user_postcopy_waker_nomatch(qemu_ram_get_idstr(rb), offset);
1178     return 0;
1179 }
1180
1181 /*
1182  * Called at the start of an inbound postcopy on reception of the
1183  * 'advise' command.
1184  */
1185 static int vhost_user_postcopy_advise(struct vhost_dev *dev, Error **errp)
1186 {
1187     struct vhost_user *u = dev->opaque;
1188     CharBackend *chr = u->user->chr;
1189     int ufd;
1190     VhostUserMsg msg = {
1191         .hdr.request = VHOST_USER_POSTCOPY_ADVISE,
1192         .hdr.flags = VHOST_USER_VERSION,
1193     };
1194
1195     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1196         error_setg(errp, "Failed to send postcopy_advise to vhost");
1197         return -1;
1198     }
1199
1200     if (vhost_user_read(dev, &msg) < 0) {
1201         error_setg(errp, "Failed to get postcopy_advise reply from vhost");
1202         return -1;
1203     }
1204
1205     if (msg.hdr.request != VHOST_USER_POSTCOPY_ADVISE) {
1206         error_setg(errp, "Unexpected msg type. Expected %d received %d",
1207                      VHOST_USER_POSTCOPY_ADVISE, msg.hdr.request);
1208         return -1;
1209     }
1210
1211     if (msg.hdr.size) {
1212         error_setg(errp, "Received bad msg size.");
1213         return -1;
1214     }
1215     ufd = qemu_chr_fe_get_msgfd(chr);
1216     if (ufd < 0) {
1217         error_setg(errp, "%s: Failed to get ufd", __func__);
1218         return -1;
1219     }
1220     qemu_set_nonblock(ufd);
1221
1222     /* register ufd with userfault thread */
1223     u->postcopy_fd.fd = ufd;
1224     u->postcopy_fd.data = dev;
1225     u->postcopy_fd.handler = vhost_user_postcopy_fault_handler;
1226     u->postcopy_fd.waker = vhost_user_postcopy_waker;
1227     u->postcopy_fd.idstr = "vhost-user"; /* Need to find unique name */
1228     postcopy_register_shared_ufd(&u->postcopy_fd);
1229     return 0;
1230 }
1231
1232 /*
1233  * Called at the switch to postcopy on reception of the 'listen' command.
1234  */
1235 static int vhost_user_postcopy_listen(struct vhost_dev *dev, Error **errp)
1236 {
1237     struct vhost_user *u = dev->opaque;
1238     int ret;
1239     VhostUserMsg msg = {
1240         .hdr.request = VHOST_USER_POSTCOPY_LISTEN,
1241         .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1242     };
1243     u->postcopy_listen = true;
1244     trace_vhost_user_postcopy_listen();
1245     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1246         error_setg(errp, "Failed to send postcopy_listen to vhost");
1247         return -1;
1248     }
1249
1250     ret = process_message_reply(dev, &msg);
1251     if (ret) {
1252         error_setg(errp, "Failed to receive reply to postcopy_listen");
1253         return ret;
1254     }
1255
1256     return 0;
1257 }
1258
1259 /*
1260  * Called at the end of postcopy
1261  */
1262 static int vhost_user_postcopy_end(struct vhost_dev *dev, Error **errp)
1263 {
1264     VhostUserMsg msg = {
1265         .hdr.request = VHOST_USER_POSTCOPY_END,
1266         .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1267     };
1268     int ret;
1269     struct vhost_user *u = dev->opaque;
1270
1271     trace_vhost_user_postcopy_end_entry();
1272     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1273         error_setg(errp, "Failed to send postcopy_end to vhost");
1274         return -1;
1275     }
1276
1277     ret = process_message_reply(dev, &msg);
1278     if (ret) {
1279         error_setg(errp, "Failed to receive reply to postcopy_end");
1280         return ret;
1281     }
1282     postcopy_unregister_shared_ufd(&u->postcopy_fd);
1283     close(u->postcopy_fd.fd);
1284     u->postcopy_fd.handler = NULL;
1285
1286     trace_vhost_user_postcopy_end_exit();
1287
1288     return 0;
1289 }
1290
1291 static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier,
1292                                         void *opaque)
1293 {
1294     struct PostcopyNotifyData *pnd = opaque;
1295     struct vhost_user *u = container_of(notifier, struct vhost_user,
1296                                          postcopy_notifier);
1297     struct vhost_dev *dev = u->dev;
1298
1299     switch (pnd->reason) {
1300     case POSTCOPY_NOTIFY_PROBE:
1301         if (!virtio_has_feature(dev->protocol_features,
1302                                 VHOST_USER_PROTOCOL_F_PAGEFAULT)) {
1303             /* TODO: Get the device name into this error somehow */
1304             error_setg(pnd->errp,
1305                        "vhost-user backend not capable of postcopy");
1306             return -ENOENT;
1307         }
1308         break;
1309
1310     case POSTCOPY_NOTIFY_INBOUND_ADVISE:
1311         return vhost_user_postcopy_advise(dev, pnd->errp);
1312
1313     case POSTCOPY_NOTIFY_INBOUND_LISTEN:
1314         return vhost_user_postcopy_listen(dev, pnd->errp);
1315
1316     case POSTCOPY_NOTIFY_INBOUND_END:
1317         return vhost_user_postcopy_end(dev, pnd->errp);
1318
1319     default:
1320         /* We ignore notifications we don't know */
1321         break;
1322     }
1323
1324     return 0;
1325 }
1326
1327 static int vhost_user_backend_init(struct vhost_dev *dev, void *opaque)
1328 {
1329     uint64_t features, protocol_features;
1330     struct vhost_user *u;
1331     int err;
1332
1333     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1334
1335     u = g_new0(struct vhost_user, 1);
1336     u->user = opaque;
1337     u->slave_fd = -1;
1338     u->dev = dev;
1339     dev->opaque = u;
1340
1341     err = vhost_user_get_features(dev, &features);
1342     if (err < 0) {
1343         return err;
1344     }
1345
1346     if (virtio_has_feature(features, VHOST_USER_F_PROTOCOL_FEATURES)) {
1347         dev->backend_features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
1348
1349         err = vhost_user_get_u64(dev, VHOST_USER_GET_PROTOCOL_FEATURES,
1350                                  &protocol_features);
1351         if (err < 0) {
1352             return err;
1353         }
1354
1355         dev->protocol_features =
1356             protocol_features & VHOST_USER_PROTOCOL_FEATURE_MASK;
1357
1358         if (!dev->config_ops || !dev->config_ops->vhost_dev_config_notifier) {
1359             /* Don't acknowledge CONFIG feature if device doesn't support it */
1360             dev->protocol_features &= ~(1ULL << VHOST_USER_PROTOCOL_F_CONFIG);
1361         } else if (!(protocol_features &
1362                     (1ULL << VHOST_USER_PROTOCOL_F_CONFIG))) {
1363             error_report("Device expects VHOST_USER_PROTOCOL_F_CONFIG "
1364                     "but backend does not support it.");
1365             return -1;
1366         }
1367
1368         err = vhost_user_set_protocol_features(dev, dev->protocol_features);
1369         if (err < 0) {
1370             return err;
1371         }
1372
1373         /* query the max queues we support if backend supports Multiple Queue */
1374         if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ)) {
1375             err = vhost_user_get_u64(dev, VHOST_USER_GET_QUEUE_NUM,
1376                                      &dev->max_queues);
1377             if (err < 0) {
1378                 return err;
1379             }
1380         }
1381
1382         if (virtio_has_feature(features, VIRTIO_F_IOMMU_PLATFORM) &&
1383                 !(virtio_has_feature(dev->protocol_features,
1384                     VHOST_USER_PROTOCOL_F_SLAVE_REQ) &&
1385                  virtio_has_feature(dev->protocol_features,
1386                     VHOST_USER_PROTOCOL_F_REPLY_ACK))) {
1387             error_report("IOMMU support requires reply-ack and "
1388                          "slave-req protocol features.");
1389             return -1;
1390         }
1391     }
1392
1393     if (dev->migration_blocker == NULL &&
1394         !virtio_has_feature(dev->protocol_features,
1395                             VHOST_USER_PROTOCOL_F_LOG_SHMFD)) {
1396         error_setg(&dev->migration_blocker,
1397                    "Migration disabled: vhost-user backend lacks "
1398                    "VHOST_USER_PROTOCOL_F_LOG_SHMFD feature.");
1399     }
1400
1401     err = vhost_setup_slave_channel(dev);
1402     if (err < 0) {
1403         return err;
1404     }
1405
1406     u->postcopy_notifier.notify = vhost_user_postcopy_notifier;
1407     postcopy_add_notifier(&u->postcopy_notifier);
1408
1409     return 0;
1410 }
1411
1412 static int vhost_user_backend_cleanup(struct vhost_dev *dev)
1413 {
1414     struct vhost_user *u;
1415
1416     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1417
1418     u = dev->opaque;
1419     if (u->postcopy_notifier.notify) {
1420         postcopy_remove_notifier(&u->postcopy_notifier);
1421         u->postcopy_notifier.notify = NULL;
1422     }
1423     u->postcopy_listen = false;
1424     if (u->postcopy_fd.handler) {
1425         postcopy_unregister_shared_ufd(&u->postcopy_fd);
1426         close(u->postcopy_fd.fd);
1427         u->postcopy_fd.handler = NULL;
1428     }
1429     if (u->slave_fd >= 0) {
1430         qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
1431         close(u->slave_fd);
1432         u->slave_fd = -1;
1433     }
1434     g_free(u->region_rb);
1435     u->region_rb = NULL;
1436     g_free(u->region_rb_offset);
1437     u->region_rb_offset = NULL;
1438     u->region_rb_len = 0;
1439     g_free(u);
1440     dev->opaque = 0;
1441
1442     return 0;
1443 }
1444
1445 static int vhost_user_get_vq_index(struct vhost_dev *dev, int idx)
1446 {
1447     assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
1448
1449     return idx;
1450 }
1451
1452 static int vhost_user_memslots_limit(struct vhost_dev *dev)
1453 {
1454     return VHOST_MEMORY_MAX_NREGIONS;
1455 }
1456
1457 static bool vhost_user_requires_shm_log(struct vhost_dev *dev)
1458 {
1459     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1460
1461     return virtio_has_feature(dev->protocol_features,
1462                               VHOST_USER_PROTOCOL_F_LOG_SHMFD);
1463 }
1464
1465 static int vhost_user_migration_done(struct vhost_dev *dev, char* mac_addr)
1466 {
1467     VhostUserMsg msg = { };
1468
1469     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1470
1471     /* If guest supports GUEST_ANNOUNCE do nothing */
1472     if (virtio_has_feature(dev->acked_features, VIRTIO_NET_F_GUEST_ANNOUNCE)) {
1473         return 0;
1474     }
1475
1476     /* if backend supports VHOST_USER_PROTOCOL_F_RARP ask it to send the RARP */
1477     if (virtio_has_feature(dev->protocol_features,
1478                            VHOST_USER_PROTOCOL_F_RARP)) {
1479         msg.hdr.request = VHOST_USER_SEND_RARP;
1480         msg.hdr.flags = VHOST_USER_VERSION;
1481         memcpy((char *)&msg.payload.u64, mac_addr, 6);
1482         msg.hdr.size = sizeof(msg.payload.u64);
1483
1484         return vhost_user_write(dev, &msg, NULL, 0);
1485     }
1486     return -1;
1487 }
1488
1489 static bool vhost_user_can_merge(struct vhost_dev *dev,
1490                                  uint64_t start1, uint64_t size1,
1491                                  uint64_t start2, uint64_t size2)
1492 {
1493     ram_addr_t offset;
1494     int mfd, rfd;
1495     MemoryRegion *mr;
1496
1497     mr = memory_region_from_host((void *)(uintptr_t)start1, &offset);
1498     mfd = memory_region_get_fd(mr);
1499
1500     mr = memory_region_from_host((void *)(uintptr_t)start2, &offset);
1501     rfd = memory_region_get_fd(mr);
1502
1503     return mfd == rfd;
1504 }
1505
1506 static int vhost_user_net_set_mtu(struct vhost_dev *dev, uint16_t mtu)
1507 {
1508     VhostUserMsg msg;
1509     bool reply_supported = virtio_has_feature(dev->protocol_features,
1510                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
1511
1512     if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_NET_MTU))) {
1513         return 0;
1514     }
1515
1516     msg.hdr.request = VHOST_USER_NET_SET_MTU;
1517     msg.payload.u64 = mtu;
1518     msg.hdr.size = sizeof(msg.payload.u64);
1519     msg.hdr.flags = VHOST_USER_VERSION;
1520     if (reply_supported) {
1521         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
1522     }
1523
1524     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1525         return -1;
1526     }
1527
1528     /* If reply_ack supported, slave has to ack specified MTU is valid */
1529     if (reply_supported) {
1530         return process_message_reply(dev, &msg);
1531     }
1532
1533     return 0;
1534 }
1535
1536 static int vhost_user_send_device_iotlb_msg(struct vhost_dev *dev,
1537                                             struct vhost_iotlb_msg *imsg)
1538 {
1539     VhostUserMsg msg = {
1540         .hdr.request = VHOST_USER_IOTLB_MSG,
1541         .hdr.size = sizeof(msg.payload.iotlb),
1542         .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
1543         .payload.iotlb = *imsg,
1544     };
1545
1546     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1547         return -EFAULT;
1548     }
1549
1550     return process_message_reply(dev, &msg);
1551 }
1552
1553
1554 static void vhost_user_set_iotlb_callback(struct vhost_dev *dev, int enabled)
1555 {
1556     /* No-op as the receive channel is not dedicated to IOTLB messages. */
1557 }
1558
1559 static int vhost_user_get_config(struct vhost_dev *dev, uint8_t *config,
1560                                  uint32_t config_len)
1561 {
1562     VhostUserMsg msg = {
1563         .hdr.request = VHOST_USER_GET_CONFIG,
1564         .hdr.flags = VHOST_USER_VERSION,
1565         .hdr.size = VHOST_USER_CONFIG_HDR_SIZE + config_len,
1566     };
1567
1568     if (!virtio_has_feature(dev->protocol_features,
1569                 VHOST_USER_PROTOCOL_F_CONFIG)) {
1570         return -1;
1571     }
1572
1573     if (config_len > VHOST_USER_MAX_CONFIG_SIZE) {
1574         return -1;
1575     }
1576
1577     msg.payload.config.offset = 0;
1578     msg.payload.config.size = config_len;
1579     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1580         return -1;
1581     }
1582
1583     if (vhost_user_read(dev, &msg) < 0) {
1584         return -1;
1585     }
1586
1587     if (msg.hdr.request != VHOST_USER_GET_CONFIG) {
1588         error_report("Received unexpected msg type. Expected %d received %d",
1589                      VHOST_USER_GET_CONFIG, msg.hdr.request);
1590         return -1;
1591     }
1592
1593     if (msg.hdr.size != VHOST_USER_CONFIG_HDR_SIZE + config_len) {
1594         error_report("Received bad msg size.");
1595         return -1;
1596     }
1597
1598     memcpy(config, msg.payload.config.region, config_len);
1599
1600     return 0;
1601 }
1602
1603 static int vhost_user_set_config(struct vhost_dev *dev, const uint8_t *data,
1604                                  uint32_t offset, uint32_t size, uint32_t flags)
1605 {
1606     uint8_t *p;
1607     bool reply_supported = virtio_has_feature(dev->protocol_features,
1608                                               VHOST_USER_PROTOCOL_F_REPLY_ACK);
1609
1610     VhostUserMsg msg = {
1611         .hdr.request = VHOST_USER_SET_CONFIG,
1612         .hdr.flags = VHOST_USER_VERSION,
1613         .hdr.size = VHOST_USER_CONFIG_HDR_SIZE + size,
1614     };
1615
1616     if (!virtio_has_feature(dev->protocol_features,
1617                 VHOST_USER_PROTOCOL_F_CONFIG)) {
1618         return -1;
1619     }
1620
1621     if (reply_supported) {
1622         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
1623     }
1624
1625     if (size > VHOST_USER_MAX_CONFIG_SIZE) {
1626         return -1;
1627     }
1628
1629     msg.payload.config.offset = offset,
1630     msg.payload.config.size = size,
1631     msg.payload.config.flags = flags,
1632     p = msg.payload.config.region;
1633     memcpy(p, data, size);
1634
1635     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1636         return -1;
1637     }
1638
1639     if (reply_supported) {
1640         return process_message_reply(dev, &msg);
1641     }
1642
1643     return 0;
1644 }
1645
1646 static int vhost_user_crypto_create_session(struct vhost_dev *dev,
1647                                             void *session_info,
1648                                             uint64_t *session_id)
1649 {
1650     bool crypto_session = virtio_has_feature(dev->protocol_features,
1651                                        VHOST_USER_PROTOCOL_F_CRYPTO_SESSION);
1652     CryptoDevBackendSymSessionInfo *sess_info = session_info;
1653     VhostUserMsg msg = {
1654         .hdr.request = VHOST_USER_CREATE_CRYPTO_SESSION,
1655         .hdr.flags = VHOST_USER_VERSION,
1656         .hdr.size = sizeof(msg.payload.session),
1657     };
1658
1659     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
1660
1661     if (!crypto_session) {
1662         error_report("vhost-user trying to send unhandled ioctl");
1663         return -1;
1664     }
1665
1666     memcpy(&msg.payload.session.session_setup_data, sess_info,
1667               sizeof(CryptoDevBackendSymSessionInfo));
1668     if (sess_info->key_len) {
1669         memcpy(&msg.payload.session.key, sess_info->cipher_key,
1670                sess_info->key_len);
1671     }
1672     if (sess_info->auth_key_len > 0) {
1673         memcpy(&msg.payload.session.auth_key, sess_info->auth_key,
1674                sess_info->auth_key_len);
1675     }
1676     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1677         error_report("vhost_user_write() return -1, create session failed");
1678         return -1;
1679     }
1680
1681     if (vhost_user_read(dev, &msg) < 0) {
1682         error_report("vhost_user_read() return -1, create session failed");
1683         return -1;
1684     }
1685
1686     if (msg.hdr.request != VHOST_USER_CREATE_CRYPTO_SESSION) {
1687         error_report("Received unexpected msg type. Expected %d received %d",
1688                      VHOST_USER_CREATE_CRYPTO_SESSION, msg.hdr.request);
1689         return -1;
1690     }
1691
1692     if (msg.hdr.size != sizeof(msg.payload.session)) {
1693         error_report("Received bad msg size.");
1694         return -1;
1695     }
1696
1697     if (msg.payload.session.session_id < 0) {
1698         error_report("Bad session id: %" PRId64 "",
1699                               msg.payload.session.session_id);
1700         return -1;
1701     }
1702     *session_id = msg.payload.session.session_id;
1703
1704     return 0;
1705 }
1706
1707 static int
1708 vhost_user_crypto_close_session(struct vhost_dev *dev, uint64_t session_id)
1709 {
1710     bool crypto_session = virtio_has_feature(dev->protocol_features,
1711                                        VHOST_USER_PROTOCOL_F_CRYPTO_SESSION);
1712     VhostUserMsg msg = {
1713         .hdr.request = VHOST_USER_CLOSE_CRYPTO_SESSION,
1714         .hdr.flags = VHOST_USER_VERSION,
1715         .hdr.size = sizeof(msg.payload.u64),
1716     };
1717     msg.payload.u64 = session_id;
1718
1719     if (!crypto_session) {
1720         error_report("vhost-user trying to send unhandled ioctl");
1721         return -1;
1722     }
1723
1724     if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
1725         error_report("vhost_user_write() return -1, close session failed");
1726         return -1;
1727     }
1728
1729     return 0;
1730 }
1731
1732 static bool vhost_user_mem_section_filter(struct vhost_dev *dev,
1733                                           MemoryRegionSection *section)
1734 {
1735     bool result;
1736
1737     result = memory_region_get_fd(section->mr) >= 0;
1738
1739     return result;
1740 }
1741
1742 VhostUserState *vhost_user_init(void)
1743 {
1744     VhostUserState *user = g_new0(struct VhostUserState, 1);
1745
1746     return user;
1747 }
1748
1749 void vhost_user_cleanup(VhostUserState *user)
1750 {
1751     int i;
1752
1753     for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
1754         if (user->notifier[i].addr) {
1755             object_unparent(OBJECT(&user->notifier[i].mr));
1756             munmap(user->notifier[i].addr, qemu_real_host_page_size);
1757             user->notifier[i].addr = NULL;
1758         }
1759     }
1760 }
1761
1762 const VhostOps user_ops = {
1763         .backend_type = VHOST_BACKEND_TYPE_USER,
1764         .vhost_backend_init = vhost_user_backend_init,
1765         .vhost_backend_cleanup = vhost_user_backend_cleanup,
1766         .vhost_backend_memslots_limit = vhost_user_memslots_limit,
1767         .vhost_set_log_base = vhost_user_set_log_base,
1768         .vhost_set_mem_table = vhost_user_set_mem_table,
1769         .vhost_set_vring_addr = vhost_user_set_vring_addr,
1770         .vhost_set_vring_endian = vhost_user_set_vring_endian,
1771         .vhost_set_vring_num = vhost_user_set_vring_num,
1772         .vhost_set_vring_base = vhost_user_set_vring_base,
1773         .vhost_get_vring_base = vhost_user_get_vring_base,
1774         .vhost_set_vring_kick = vhost_user_set_vring_kick,
1775         .vhost_set_vring_call = vhost_user_set_vring_call,
1776         .vhost_set_features = vhost_user_set_features,
1777         .vhost_get_features = vhost_user_get_features,
1778         .vhost_set_owner = vhost_user_set_owner,
1779         .vhost_reset_device = vhost_user_reset_device,
1780         .vhost_get_vq_index = vhost_user_get_vq_index,
1781         .vhost_set_vring_enable = vhost_user_set_vring_enable,
1782         .vhost_requires_shm_log = vhost_user_requires_shm_log,
1783         .vhost_migration_done = vhost_user_migration_done,
1784         .vhost_backend_can_merge = vhost_user_can_merge,
1785         .vhost_net_set_mtu = vhost_user_net_set_mtu,
1786         .vhost_set_iotlb_callback = vhost_user_set_iotlb_callback,
1787         .vhost_send_device_iotlb_msg = vhost_user_send_device_iotlb_msg,
1788         .vhost_get_config = vhost_user_get_config,
1789         .vhost_set_config = vhost_user_set_config,
1790         .vhost_crypto_create_session = vhost_user_crypto_create_session,
1791         .vhost_crypto_close_session = vhost_user_crypto_close_session,
1792         .vhost_backend_mem_section_filter = vhost_user_mem_section_filter,
1793 };