drivers/vhost/vsock.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * vhost transport for vsock
   4  *
   5  * Copyright (C) 2013-2015 Red Hat, Inc.
   6  * Author: Asias He <asias@redhat.com>
   7  *         Stefan Hajnoczi <stefanha@redhat.com>
   8  */
   9 #include <linux/miscdevice.h>
  10 #include <linux/atomic.h>
  11 #include <linux/module.h>
  12 #include <linux/mutex.h>
  13 #include <linux/vmalloc.h>
  14 #include <net/sock.h>
  15 #include <linux/virtio_vsock.h>
  16 #include <linux/vhost.h>
  17 #include <linux/hashtable.h>
  18
  19 #include <net/af_vsock.h>
  20 #include "vhost.h"
  21
  22 #define VHOST_VSOCK_DEFAULT_HOST_CID    2
  23 /* Max number of bytes transferred before requeueing the job.
  24  * Using this limit prevents one virtqueue from starving others. */
  25 #define VHOST_VSOCK_WEIGHT 0x80000
  26 /* Max number of packets transferred before requeueing the job.
  27  * Using this limit prevents one virtqueue from starving others with
  28  * small pkts.
  29  */
  30 #define VHOST_VSOCK_PKT_WEIGHT 256
  31
  32 enum {
  33         VHOST_VSOCK_FEATURES = VHOST_FEATURES,
  34 };
  35
  36 /* Used to track all the vhost_vsock instances on the system. */
  37 static DEFINE_MUTEX(vhost_vsock_mutex);
  38 static DEFINE_READ_MOSTLY_HASHTABLE(vhost_vsock_hash, 8);
  39
  40 struct vhost_vsock {
  41         struct vhost_dev dev;
  42         struct vhost_virtqueue vqs[2];
  43
  44         /* Link to global vhost_vsock_hash, writes use vhost_vsock_mutex */
  45         struct hlist_node hash;
  46
  47         struct vhost_work send_pkt_work;
  48         spinlock_t send_pkt_list_lock;
  49         struct list_head send_pkt_list; /* host->guest pending packets */
  50
  51         atomic_t queued_replies;
  52
  53         u32 guest_cid;
  54 };
  55
  56 static u32 vhost_transport_get_local_cid(void)
  57 {
  58         return VHOST_VSOCK_DEFAULT_HOST_CID;
  59 }
  60
  61 /* Callers that dereference the return value must hold vhost_vsock_mutex or the
  62  * RCU read lock.
  63  */
  64 static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
  65 {
  66         struct vhost_vsock *vsock;
  67
  68         hash_for_each_possible_rcu(vhost_vsock_hash, vsock, hash, guest_cid) {
  69                 u32 other_cid = vsock->guest_cid;
  70
  71                 /* Skip instances that have no CID yet */
  72                 if (other_cid == 0)
  73                         continue;
  74
  75                 if (other_cid == guest_cid)
  76                         return vsock;
  77
  78         }
  79
  80         return NULL;
  81 }
  82
  83 static void
  84 vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
  85                             struct vhost_virtqueue *vq)
  86 {
  87         struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
  88         int pkts = 0, total_len = 0;
  89         bool added = false;
  90         bool restart_tx = false;
  91
  92         mutex_lock(&vq->mutex);
  93
  94         if (!vq->private_data)
  95                 goto out;
  96
  97         /* Avoid further vmexits, we're already processing the virtqueue */
  98         vhost_disable_notify(&vsock->dev, vq);
  99
 100         do {
 101                 struct virtio_vsock_pkt *pkt;
 102                 struct iov_iter iov_iter;
 103                 unsigned out, in;
 104                 size_t nbytes;
 105                 size_t len;
 106                 int head;
 107
 108                 spin_lock_bh(&vsock->send_pkt_list_lock);
 109                 if (list_empty(&vsock->send_pkt_list)) {
 110                         spin_unlock_bh(&vsock->send_pkt_list_lock);
 111                         vhost_enable_notify(&vsock->dev, vq);
 112                         break;
 113                 }
 114
 115                 pkt = list_first_entry(&vsock->send_pkt_list,
 116                                        struct virtio_vsock_pkt, list);
 117                 list_del_init(&pkt->list);
 118                 spin_unlock_bh(&vsock->send_pkt_list_lock);
 119
 120                 head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
 121                                          &out, &in, NULL, NULL);
 122                 if (head < 0) {
 123                         spin_lock_bh(&vsock->send_pkt_list_lock);
 124                         list_add(&pkt->list, &vsock->send_pkt_list);
 125                         spin_unlock_bh(&vsock->send_pkt_list_lock);
 126                         break;
 127                 }
 128
 129                 if (head == vq->num) {
 130                         spin_lock_bh(&vsock->send_pkt_list_lock);
 131                         list_add(&pkt->list, &vsock->send_pkt_list);
 132                         spin_unlock_bh(&vsock->send_pkt_list_lock);
 133
 134                         /* We cannot finish yet if more buffers snuck in while
 135                          * re-enabling notify.
 136                          */
 137                         if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
 138                                 vhost_disable_notify(&vsock->dev, vq);
 139                                 continue;
 140                         }
 141                         break;
 142                 }
 143
 144                 if (out) {
 145                         virtio_transport_free_pkt(pkt);
 146                         vq_err(vq, "Expected 0 output buffers, got %u\n", out);
 147                         break;
 148                 }
 149
 150                 len = iov_length(&vq->iov[out], in);
 151                 iov_iter_init(&iov_iter, READ, &vq->iov[out], in, len);
 152
 153                 nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
 154                 if (nbytes != sizeof(pkt->hdr)) {
 155                         virtio_transport_free_pkt(pkt);
 156                         vq_err(vq, "Faulted on copying pkt hdr\n");
 157                         break;
 158                 }
 159
 160                 nbytes = copy_to_iter(pkt->buf, pkt->len, &iov_iter);
 161                 if (nbytes != pkt->len) {
 162                         virtio_transport_free_pkt(pkt);
 163                         vq_err(vq, "Faulted on copying pkt buf\n");
 164                         break;
 165                 }
 166
 167                 vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len);
 168                 added = true;
 169
 170                 if (pkt->reply) {
 171                         int val;
 172
 173                         val = atomic_dec_return(&vsock->queued_replies);
 174
 175                         /* Do we have resources to resume tx processing? */
 176                         if (val + 1 == tx_vq->num)
 177                                 restart_tx = true;
 178                 }
 179
 180                 /* Deliver to monitoring devices all correctly transmitted
 181                  * packets.
 182                  */
 183                 virtio_transport_deliver_tap_pkt(pkt);
 184
 185                 total_len += pkt->len;
 186                 virtio_transport_free_pkt(pkt);
 187         } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len)));
 188         if (added)
 189                 vhost_signal(&vsock->dev, vq);
 190
 191 out:
 192         mutex_unlock(&vq->mutex);
 193
 194         if (restart_tx)
 195                 vhost_poll_queue(&tx_vq->poll);
 196 }
 197
 198 static void vhost_transport_send_pkt_work(struct vhost_work *work)
 199 {
 200         struct vhost_virtqueue *vq;
 201         struct vhost_vsock *vsock;
 202
 203         vsock = container_of(work, struct vhost_vsock, send_pkt_work);
 204         vq = &vsock->vqs[VSOCK_VQ_RX];
 205
 206         vhost_transport_do_send_pkt(vsock, vq);
 207 }
 208
 209 static int
 210 vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt)
 211 {
 212         struct vhost_vsock *vsock;
 213         int len = pkt->len;
 214
 215         rcu_read_lock();
 216
 217         /* Find the vhost_vsock according to guest context id  */
 218         vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid));
 219         if (!vsock) {
 220                 rcu_read_unlock();
 221                 virtio_transport_free_pkt(pkt);
 222                 return -ENODEV;
 223         }
 224
 225         if (pkt->reply)
 226                 atomic_inc(&vsock->queued_replies);
 227
 228         spin_lock_bh(&vsock->send_pkt_list_lock);
 229         list_add_tail(&pkt->list, &vsock->send_pkt_list);
 230         spin_unlock_bh(&vsock->send_pkt_list_lock);
 231
 232         vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
 233
 234         rcu_read_unlock();
 235         return len;
 236 }
 237
 238 static int
 239 vhost_transport_cancel_pkt(struct vsock_sock *vsk)
 240 {
 241         struct vhost_vsock *vsock;
 242         struct virtio_vsock_pkt *pkt, *n;
 243         int cnt = 0;
 244         int ret = -ENODEV;
 245         LIST_HEAD(freeme);
 246
 247         rcu_read_lock();
 248
 249         /* Find the vhost_vsock according to guest context id  */
 250         vsock = vhost_vsock_get(vsk->remote_addr.svm_cid);
 251         if (!vsock)
 252                 goto out;
 253
 254         spin_lock_bh(&vsock->send_pkt_list_lock);
 255         list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
 256                 if (pkt->vsk != vsk)
 257                         continue;
 258                 list_move(&pkt->list, &freeme);
 259         }
 260         spin_unlock_bh(&vsock->send_pkt_list_lock);
 261
 262         list_for_each_entry_safe(pkt, n, &freeme, list) {
 263                 if (pkt->reply)
 264                         cnt++;
 265                 list_del(&pkt->list);
 266                 virtio_transport_free_pkt(pkt);
 267         }
 268
 269         if (cnt) {
 270                 struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
 271                 int new_cnt;
 272
 273                 new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
 274                 if (new_cnt + cnt >= tx_vq->num && new_cnt < tx_vq->num)
 275                         vhost_poll_queue(&tx_vq->poll);
 276         }
 277
 278         ret = 0;
 279 out:
 280         rcu_read_unlock();
 281         return ret;
 282 }
 283
 284 static struct virtio_vsock_pkt *
 285 vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
 286                       unsigned int out, unsigned int in)
 287 {
 288         struct virtio_vsock_pkt *pkt;
 289         struct iov_iter iov_iter;
 290         size_t nbytes;
 291         size_t len;
 292
 293         if (in != 0) {
 294                 vq_err(vq, "Expected 0 input buffers, got %u\n", in);
 295                 return NULL;
 296         }
 297
 298         pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
 299         if (!pkt)
 300                 return NULL;
 301
 302         len = iov_length(vq->iov, out);
 303         iov_iter_init(&iov_iter, WRITE, vq->iov, out, len);
 304
 305         nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
 306         if (nbytes != sizeof(pkt->hdr)) {
 307                 vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n",
 308                        sizeof(pkt->hdr), nbytes);
 309                 kfree(pkt);
 310                 return NULL;
 311         }
 312
 313         if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_STREAM)
 314                 pkt->len = le32_to_cpu(pkt->hdr.len);
 315
 316         /* No payload */
 317         if (!pkt->len)
 318                 return pkt;
 319
 320         /* The pkt is too big */
 321         if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
 322                 kfree(pkt);
 323                 return NULL;
 324         }
 325
 326         pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
 327         if (!pkt->buf) {
 328                 kfree(pkt);
 329                 return NULL;
 330         }
 331
 332         nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter);
 333         if (nbytes != pkt->len) {
 334                 vq_err(vq, "Expected %u byte payload, got %zu bytes\n",
 335                        pkt->len, nbytes);
 336                 virtio_transport_free_pkt(pkt);
 337                 return NULL;
 338         }
 339
 340         return pkt;
 341 }
 342
 343 /* Is there space left for replies to rx packets? */
 344 static bool vhost_vsock_more_replies(struct vhost_vsock *vsock)
 345 {
 346         struct vhost_virtqueue *vq = &vsock->vqs[VSOCK_VQ_TX];
 347         int val;
 348
 349         smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
 350         val = atomic_read(&vsock->queued_replies);
 351
 352         return val < vq->num;
 353 }
 354
 355 static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
 356 {
 357         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
 358                                                   poll.work);
 359         struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
 360                                                  dev);
 361         struct virtio_vsock_pkt *pkt;
 362         int head, pkts = 0, total_len = 0;
 363         unsigned int out, in;
 364         bool added = false;
 365
 366         mutex_lock(&vq->mutex);
 367
 368         if (!vq->private_data)
 369                 goto out;
 370
 371         vhost_disable_notify(&vsock->dev, vq);
 372         do {
 373                 u32 len;
 374
 375                 if (!vhost_vsock_more_replies(vsock)) {
 376                         /* Stop tx until the device processes already
 377                          * pending replies.  Leave tx virtqueue
 378                          * callbacks disabled.
 379                          */
 380                         goto no_more_replies;
 381                 }
 382
 383                 head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
 384                                          &out, &in, NULL, NULL);
 385                 if (head < 0)
 386                         break;
 387
 388                 if (head == vq->num) {
 389                         if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
 390                                 vhost_disable_notify(&vsock->dev, vq);
 391                                 continue;
 392                         }
 393                         break;
 394                 }
 395
 396                 pkt = vhost_vsock_alloc_pkt(vq, out, in);
 397                 if (!pkt) {
 398                         vq_err(vq, "Faulted on pkt\n");
 399                         continue;
 400                 }
 401
 402                 len = pkt->len;
 403
 404                 /* Deliver to monitoring devices all received packets */
 405                 virtio_transport_deliver_tap_pkt(pkt);
 406
 407                 /* Only accept correctly addressed packets */
 408                 if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid)
 409                         virtio_transport_recv_pkt(pkt);
 410                 else
 411                         virtio_transport_free_pkt(pkt);
 412
 413                 len += sizeof(pkt->hdr);
 414                 vhost_add_used(vq, head, len);
 415                 total_len += len;
 416                 added = true;
 417         } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len)));
 418
 419 no_more_replies:
 420         if (added)
 421                 vhost_signal(&vsock->dev, vq);
 422
 423 out:
 424         mutex_unlock(&vq->mutex);
 425 }
 426
 427 static void vhost_vsock_handle_rx_kick(struct vhost_work *work)
 428 {
 429         struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
 430                                                 poll.work);
 431         struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
 432                                                  dev);
 433
 434         vhost_transport_do_send_pkt(vsock, vq);
 435 }
 436
 437 static int vhost_vsock_start(struct vhost_vsock *vsock)
 438 {
 439         struct vhost_virtqueue *vq;
 440         size_t i;
 441         int ret;
 442
 443         mutex_lock(&vsock->dev.mutex);
 444
 445         ret = vhost_dev_check_owner(&vsock->dev);
 446         if (ret)
 447                 goto err;
 448
 449         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
 450                 vq = &vsock->vqs[i];
 451
 452                 mutex_lock(&vq->mutex);
 453
 454                 if (!vhost_vq_access_ok(vq)) {
 455                         ret = -EFAULT;
 456                         goto err_vq;
 457                 }
 458
 459                 if (!vq->private_data) {
 460                         vq->private_data = vsock;
 461                         ret = vhost_vq_init_access(vq);
 462                         if (ret)
 463                                 goto err_vq;
 464                 }
 465
 466                 mutex_unlock(&vq->mutex);
 467         }
 468
 469         mutex_unlock(&vsock->dev.mutex);
 470         return 0;
 471
 472 err_vq:
 473         vq->private_data = NULL;
 474         mutex_unlock(&vq->mutex);
 475
 476         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
 477                 vq = &vsock->vqs[i];
 478
 479                 mutex_lock(&vq->mutex);
 480                 vq->private_data = NULL;
 481                 mutex_unlock(&vq->mutex);
 482         }
 483 err:
 484         mutex_unlock(&vsock->dev.mutex);
 485         return ret;
 486 }
 487
 488 static int vhost_vsock_stop(struct vhost_vsock *vsock)
 489 {
 490         size_t i;
 491         int ret;
 492
 493         mutex_lock(&vsock->dev.mutex);
 494
 495         ret = vhost_dev_check_owner(&vsock->dev);
 496         if (ret)
 497                 goto err;
 498
 499         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
 500                 struct vhost_virtqueue *vq = &vsock->vqs[i];
 501
 502                 mutex_lock(&vq->mutex);
 503                 vq->private_data = NULL;
 504                 mutex_unlock(&vq->mutex);
 505         }
 506
 507 err:
 508         mutex_unlock(&vsock->dev.mutex);
 509         return ret;
 510 }
 511
 512 static void vhost_vsock_free(struct vhost_vsock *vsock)
 513 {
 514         kvfree(vsock);
 515 }
 516
 517 static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
 518 {
 519         struct vhost_virtqueue **vqs;
 520         struct vhost_vsock *vsock;
 521         int ret;
 522
 523         /* This struct is large and allocation could fail, fall back to vmalloc
 524          * if there is no other way.
 525          */
 526         vsock = kvmalloc(sizeof(*vsock), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
 527         if (!vsock)
 528                 return -ENOMEM;
 529
 530         vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL);
 531         if (!vqs) {
 532                 ret = -ENOMEM;
 533                 goto out;
 534         }
 535
 536         vsock->guest_cid = 0; /* no CID assigned yet */
 537
 538         atomic_set(&vsock->queued_replies, 0);
 539
 540         vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX];
 541         vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX];
 542         vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
 543         vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
 544
 545         vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs),
 546                        UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT,
 547                        VHOST_VSOCK_WEIGHT);
 548
 549         file->private_data = vsock;
 550         spin_lock_init(&vsock->send_pkt_list_lock);
 551         INIT_LIST_HEAD(&vsock->send_pkt_list);
 552         vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
 553         return 0;
 554
 555 out:
 556         vhost_vsock_free(vsock);
 557         return ret;
 558 }
 559
 560 static void vhost_vsock_flush(struct vhost_vsock *vsock)
 561 {
 562         int i;
 563
 564         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++)
 565                 if (vsock->vqs[i].handle_kick)
 566                         vhost_poll_flush(&vsock->vqs[i].poll);
 567         vhost_work_flush(&vsock->dev, &vsock->send_pkt_work);
 568 }
 569
 570 static void vhost_vsock_reset_orphans(struct sock *sk)
 571 {
 572         struct vsock_sock *vsk = vsock_sk(sk);
 573
 574         /* vmci_transport.c doesn't take sk_lock here either.  At least we're
 575          * under vsock_table_lock so the sock cannot disappear while we're
 576          * executing.
 577          */
 578
 579         /* If the peer is still valid, no need to reset connection */
 580         if (vhost_vsock_get(vsk->remote_addr.svm_cid))
 581                 return;
 582
 583         /* If the close timeout is pending, let it expire.  This avoids races
 584          * with the timeout callback.
 585          */
 586         if (vsk->close_work_scheduled)
 587                 return;
 588
 589         sock_set_flag(sk, SOCK_DONE);
 590         vsk->peer_shutdown = SHUTDOWN_MASK;
 591         sk->sk_state = SS_UNCONNECTED;
 592         sk->sk_err = ECONNRESET;
 593         sk->sk_error_report(sk);
 594 }
 595
 596 static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
 597 {
 598         struct vhost_vsock *vsock = file->private_data;
 599
 600         mutex_lock(&vhost_vsock_mutex);
 601         if (vsock->guest_cid)
 602                 hash_del_rcu(&vsock->hash);
 603         mutex_unlock(&vhost_vsock_mutex);
 604
 605         /* Wait for other CPUs to finish using vsock */
 606         synchronize_rcu();
 607
 608         /* Iterating over all connections for all CIDs to find orphans is
 609          * inefficient.  Room for improvement here. */
 610         vsock_for_each_connected_socket(vhost_vsock_reset_orphans);
 611
 612         vhost_vsock_stop(vsock);
 613         vhost_vsock_flush(vsock);
 614         vhost_dev_stop(&vsock->dev);
 615
 616         spin_lock_bh(&vsock->send_pkt_list_lock);
 617         while (!list_empty(&vsock->send_pkt_list)) {
 618                 struct virtio_vsock_pkt *pkt;
 619
 620                 pkt = list_first_entry(&vsock->send_pkt_list,
 621                                 struct virtio_vsock_pkt, list);
 622                 list_del_init(&pkt->list);
 623                 virtio_transport_free_pkt(pkt);
 624         }
 625         spin_unlock_bh(&vsock->send_pkt_list_lock);
 626
 627         vhost_dev_cleanup(&vsock->dev);
 628         kfree(vsock->dev.vqs);
 629         vhost_vsock_free(vsock);
 630         return 0;
 631 }
 632
 633 static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
 634 {
 635         struct vhost_vsock *other;
 636
 637         /* Refuse reserved CIDs */
 638         if (guest_cid <= VMADDR_CID_HOST ||
 639             guest_cid == U32_MAX)
 640                 return -EINVAL;
 641
 642         /* 64-bit CIDs are not yet supported */
 643         if (guest_cid > U32_MAX)
 644                 return -EINVAL;
 645
 646         /* Refuse if CID is already in use */
 647         mutex_lock(&vhost_vsock_mutex);
 648         other = vhost_vsock_get(guest_cid);
 649         if (other && other != vsock) {
 650                 mutex_unlock(&vhost_vsock_mutex);
 651                 return -EADDRINUSE;
 652         }
 653
 654         if (vsock->guest_cid)
 655                 hash_del_rcu(&vsock->hash);
 656
 657         vsock->guest_cid = guest_cid;
 658         hash_add_rcu(vhost_vsock_hash, &vsock->hash, vsock->guest_cid);
 659         mutex_unlock(&vhost_vsock_mutex);
 660
 661         return 0;
 662 }
 663
 664 static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features)
 665 {
 666         struct vhost_virtqueue *vq;
 667         int i;
 668
 669         if (features & ~VHOST_VSOCK_FEATURES)
 670                 return -EOPNOTSUPP;
 671
 672         mutex_lock(&vsock->dev.mutex);
 673         if ((features & (1 << VHOST_F_LOG_ALL)) &&
 674             !vhost_log_access_ok(&vsock->dev)) {
 675                 mutex_unlock(&vsock->dev.mutex);
 676                 return -EFAULT;
 677         }
 678
 679         for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
 680                 vq = &vsock->vqs[i];
 681                 mutex_lock(&vq->mutex);
 682                 vq->acked_features = features;
 683                 mutex_unlock(&vq->mutex);
 684         }
 685         mutex_unlock(&vsock->dev.mutex);
 686         return 0;
 687 }
 688
 689 static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
 690                                   unsigned long arg)
 691 {
 692         struct vhost_vsock *vsock = f->private_data;
 693         void __user *argp = (void __user *)arg;
 694         u64 guest_cid;
 695         u64 features;
 696         int start;
 697         int r;
 698
 699         switch (ioctl) {
 700         case VHOST_VSOCK_SET_GUEST_CID:
 701                 if (copy_from_user(&guest_cid, argp, sizeof(guest_cid)))
 702                         return -EFAULT;
 703                 return vhost_vsock_set_cid(vsock, guest_cid);
 704         case VHOST_VSOCK_SET_RUNNING:
 705                 if (copy_from_user(&start, argp, sizeof(start)))
 706                         return -EFAULT;
 707                 if (start)
 708                         return vhost_vsock_start(vsock);
 709                 else
 710                         return vhost_vsock_stop(vsock);
 711         case VHOST_GET_FEATURES:
 712                 features = VHOST_VSOCK_FEATURES;
 713                 if (copy_to_user(argp, &features, sizeof(features)))
 714                         return -EFAULT;
 715                 return 0;
 716         case VHOST_SET_FEATURES:
 717                 if (copy_from_user(&features, argp, sizeof(features)))
 718                         return -EFAULT;
 719                 return vhost_vsock_set_features(vsock, features);
 720         default:
 721                 mutex_lock(&vsock->dev.mutex);
 722                 r = vhost_dev_ioctl(&vsock->dev, ioctl, argp);
 723                 if (r == -ENOIOCTLCMD)
 724                         r = vhost_vring_ioctl(&vsock->dev, ioctl, argp);
 725                 else
 726                         vhost_vsock_flush(vsock);
 727                 mutex_unlock(&vsock->dev.mutex);
 728                 return r;
 729         }
 730 }
 731
 732 #ifdef CONFIG_COMPAT
 733 static long vhost_vsock_dev_compat_ioctl(struct file *f, unsigned int ioctl,
 734                                          unsigned long arg)
 735 {
 736         return vhost_vsock_dev_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
 737 }
 738 #endif
 739
 740 static const struct file_operations vhost_vsock_fops = {
 741         .owner          = THIS_MODULE,
 742         .open           = vhost_vsock_dev_open,
 743         .release        = vhost_vsock_dev_release,
 744         .llseek         = noop_llseek,
 745         .unlocked_ioctl = vhost_vsock_dev_ioctl,
 746 #ifdef CONFIG_COMPAT
 747         .compat_ioctl   = vhost_vsock_dev_compat_ioctl,
 748 #endif
 749 };
 750
 751 static struct miscdevice vhost_vsock_misc = {
 752         .minor = VHOST_VSOCK_MINOR,
 753         .name = "vhost-vsock",
 754         .fops = &vhost_vsock_fops,
 755 };
 756
 757 static struct virtio_transport vhost_transport = {
 758         .transport = {
 759                 .get_local_cid            = vhost_transport_get_local_cid,
 760
 761                 .init                     = virtio_transport_do_socket_init,
 762                 .destruct                 = virtio_transport_destruct,
 763                 .release                  = virtio_transport_release,
 764                 .connect                  = virtio_transport_connect,
 765                 .shutdown                 = virtio_transport_shutdown,
 766                 .cancel_pkt               = vhost_transport_cancel_pkt,
 767
 768                 .dgram_enqueue            = virtio_transport_dgram_enqueue,
 769                 .dgram_dequeue            = virtio_transport_dgram_dequeue,
 770                 .dgram_bind               = virtio_transport_dgram_bind,
 771                 .dgram_allow              = virtio_transport_dgram_allow,
 772
 773                 .stream_enqueue           = virtio_transport_stream_enqueue,
 774                 .stream_dequeue           = virtio_transport_stream_dequeue,
 775                 .stream_has_data          = virtio_transport_stream_has_data,
 776                 .stream_has_space         = virtio_transport_stream_has_space,
 777                 .stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
 778                 .stream_is_active         = virtio_transport_stream_is_active,
 779                 .stream_allow             = virtio_transport_stream_allow,
 780
 781                 .notify_poll_in           = virtio_transport_notify_poll_in,
 782                 .notify_poll_out          = virtio_transport_notify_poll_out,
 783                 .notify_recv_init         = virtio_transport_notify_recv_init,
 784                 .notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
 785                 .notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
 786                 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
 787                 .notify_send_init         = virtio_transport_notify_send_init,
 788                 .notify_send_pre_block    = virtio_transport_notify_send_pre_block,
 789                 .notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
 790                 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
 791
 792                 .set_buffer_size          = virtio_transport_set_buffer_size,
 793                 .set_min_buffer_size      = virtio_transport_set_min_buffer_size,
 794                 .set_max_buffer_size      = virtio_transport_set_max_buffer_size,
 795                 .get_buffer_size          = virtio_transport_get_buffer_size,
 796                 .get_min_buffer_size      = virtio_transport_get_min_buffer_size,
 797                 .get_max_buffer_size      = virtio_transport_get_max_buffer_size,
 798         },
 799
 800         .send_pkt = vhost_transport_send_pkt,
 801 };
 802
 803 static int __init vhost_vsock_init(void)
 804 {
 805         int ret;
 806
 807         ret = vsock_core_init(&vhost_transport.transport);
 808         if (ret < 0)
 809                 return ret;
 810         return misc_register(&vhost_vsock_misc);
 811 };
 812
 813 static void __exit vhost_vsock_exit(void)
 814 {
 815         misc_deregister(&vhost_vsock_misc);
 816         vsock_core_exit();
 817 };
 818
 819 module_init(vhost_vsock_init);
 820 module_exit(vhost_vsock_exit);
 821 MODULE_LICENSE("GPL v2");
 822 MODULE_AUTHOR("Asias He");
 823 MODULE_DESCRIPTION("vhost transport for vsock ");
 824 MODULE_ALIAS_MISCDEV(VHOST_VSOCK_MINOR);
 825 MODULE_ALIAS("devname:vhost-vsock");