| 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 | (1ULL << VIRTIO_F_ACCESS_PLATFORM) | |
| 35 | (1ULL << VIRTIO_VSOCK_F_SEQPACKET) |
| 36 | }; |
| 37 | |
| 38 | enum { |
| 39 | VHOST_VSOCK_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) |
| 40 | }; |
| 41 | |
| 42 | /* Used to track all the vhost_vsock instances on the system. */ |
| 43 | static DEFINE_MUTEX(vhost_vsock_mutex); |
| 44 | static DEFINE_READ_MOSTLY_HASHTABLE(vhost_vsock_hash, 8); |
| 45 | |
| 46 | struct vhost_vsock { |
| 47 | struct vhost_dev dev; |
| 48 | struct vhost_virtqueue vqs[2]; |
| 49 | |
| 50 | /* Link to global vhost_vsock_hash, writes use vhost_vsock_mutex */ |
| 51 | struct hlist_node hash; |
| 52 | |
| 53 | struct vhost_work send_pkt_work; |
| 54 | spinlock_t send_pkt_list_lock; |
| 55 | struct list_head send_pkt_list; /* host->guest pending packets */ |
| 56 | |
| 57 | atomic_t queued_replies; |
| 58 | |
| 59 | u32 guest_cid; |
| 60 | bool seqpacket_allow; |
| 61 | }; |
| 62 | |
| 63 | static u32 vhost_transport_get_local_cid(void) |
| 64 | { |
| 65 | return VHOST_VSOCK_DEFAULT_HOST_CID; |
| 66 | } |
| 67 | |
| 68 | /* Callers that dereference the return value must hold vhost_vsock_mutex or the |
| 69 | * RCU read lock. |
| 70 | */ |
| 71 | static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) |
| 72 | { |
| 73 | struct vhost_vsock *vsock; |
| 74 | |
| 75 | hash_for_each_possible_rcu(vhost_vsock_hash, vsock, hash, guest_cid) { |
| 76 | u32 other_cid = vsock->guest_cid; |
| 77 | |
| 78 | /* Skip instances that have no CID yet */ |
| 79 | if (other_cid == 0) |
| 80 | continue; |
| 81 | |
| 82 | if (other_cid == guest_cid) |
| 83 | return vsock; |
| 84 | |
| 85 | } |
| 86 | |
| 87 | return NULL; |
| 88 | } |
| 89 | |
| 90 | static void |
| 91 | vhost_transport_do_send_pkt(struct vhost_vsock *vsock, |
| 92 | struct vhost_virtqueue *vq) |
| 93 | { |
| 94 | struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX]; |
| 95 | int pkts = 0, total_len = 0; |
| 96 | bool added = false; |
| 97 | bool restart_tx = false; |
| 98 | |
| 99 | mutex_lock(&vq->mutex); |
| 100 | |
| 101 | if (!vhost_vq_get_backend(vq)) |
| 102 | goto out; |
| 103 | |
| 104 | if (!vq_meta_prefetch(vq)) |
| 105 | goto out; |
| 106 | |
| 107 | /* Avoid further vmexits, we're already processing the virtqueue */ |
| 108 | vhost_disable_notify(&vsock->dev, vq); |
| 109 | |
| 110 | do { |
| 111 | struct virtio_vsock_pkt *pkt; |
| 112 | struct iov_iter iov_iter; |
| 113 | unsigned out, in; |
| 114 | size_t nbytes; |
| 115 | size_t iov_len, payload_len; |
| 116 | int head; |
| 117 | bool restore_flag = false; |
| 118 | |
| 119 | spin_lock_bh(&vsock->send_pkt_list_lock); |
| 120 | if (list_empty(&vsock->send_pkt_list)) { |
| 121 | spin_unlock_bh(&vsock->send_pkt_list_lock); |
| 122 | vhost_enable_notify(&vsock->dev, vq); |
| 123 | break; |
| 124 | } |
| 125 | |
| 126 | pkt = list_first_entry(&vsock->send_pkt_list, |
| 127 | struct virtio_vsock_pkt, list); |
| 128 | list_del_init(&pkt->list); |
| 129 | spin_unlock_bh(&vsock->send_pkt_list_lock); |
| 130 | |
| 131 | head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), |
| 132 | &out, &in, NULL, NULL); |
| 133 | if (head < 0) { |
| 134 | spin_lock_bh(&vsock->send_pkt_list_lock); |
| 135 | list_add(&pkt->list, &vsock->send_pkt_list); |
| 136 | spin_unlock_bh(&vsock->send_pkt_list_lock); |
| 137 | break; |
| 138 | } |
| 139 | |
| 140 | if (head == vq->num) { |
| 141 | spin_lock_bh(&vsock->send_pkt_list_lock); |
| 142 | list_add(&pkt->list, &vsock->send_pkt_list); |
| 143 | spin_unlock_bh(&vsock->send_pkt_list_lock); |
| 144 | |
| 145 | /* We cannot finish yet if more buffers snuck in while |
| 146 | * re-enabling notify. |
| 147 | */ |
| 148 | if (unlikely(vhost_enable_notify(&vsock->dev, vq))) { |
| 149 | vhost_disable_notify(&vsock->dev, vq); |
| 150 | continue; |
| 151 | } |
| 152 | break; |
| 153 | } |
| 154 | |
| 155 | if (out) { |
| 156 | virtio_transport_free_pkt(pkt); |
| 157 | vq_err(vq, "Expected 0 output buffers, got %u\n", out); |
| 158 | break; |
| 159 | } |
| 160 | |
| 161 | iov_len = iov_length(&vq->iov[out], in); |
| 162 | if (iov_len < sizeof(pkt->hdr)) { |
| 163 | virtio_transport_free_pkt(pkt); |
| 164 | vq_err(vq, "Buffer len [%zu] too small\n", iov_len); |
| 165 | break; |
| 166 | } |
| 167 | |
| 168 | iov_iter_init(&iov_iter, READ, &vq->iov[out], in, iov_len); |
| 169 | payload_len = pkt->len - pkt->off; |
| 170 | |
| 171 | /* If the packet is greater than the space available in the |
| 172 | * buffer, we split it using multiple buffers. |
| 173 | */ |
| 174 | if (payload_len > iov_len - sizeof(pkt->hdr)) { |
| 175 | payload_len = iov_len - sizeof(pkt->hdr); |
| 176 | |
| 177 | /* As we are copying pieces of large packet's buffer to |
| 178 | * small rx buffers, headers of packets in rx queue are |
| 179 | * created dynamically and are initialized with header |
| 180 | * of current packet(except length). But in case of |
| 181 | * SOCK_SEQPACKET, we also must clear record delimeter |
| 182 | * bit(VIRTIO_VSOCK_SEQ_EOR). Otherwise, instead of one |
| 183 | * packet with delimeter(which marks end of record), |
| 184 | * there will be sequence of packets with delimeter |
| 185 | * bit set. After initialized header will be copied to |
| 186 | * rx buffer, this bit will be restored. |
| 187 | */ |
| 188 | if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR) { |
| 189 | pkt->hdr.flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR); |
| 190 | restore_flag = true; |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | /* Set the correct length in the header */ |
| 195 | pkt->hdr.len = cpu_to_le32(payload_len); |
| 196 | |
| 197 | nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter); |
| 198 | if (nbytes != sizeof(pkt->hdr)) { |
| 199 | virtio_transport_free_pkt(pkt); |
| 200 | vq_err(vq, "Faulted on copying pkt hdr\n"); |
| 201 | break; |
| 202 | } |
| 203 | |
| 204 | nbytes = copy_to_iter(pkt->buf + pkt->off, payload_len, |
| 205 | &iov_iter); |
| 206 | if (nbytes != payload_len) { |
| 207 | virtio_transport_free_pkt(pkt); |
| 208 | vq_err(vq, "Faulted on copying pkt buf\n"); |
| 209 | break; |
| 210 | } |
| 211 | |
| 212 | /* Deliver to monitoring devices all packets that we |
| 213 | * will transmit. |
| 214 | */ |
| 215 | virtio_transport_deliver_tap_pkt(pkt); |
| 216 | |
| 217 | vhost_add_used(vq, head, sizeof(pkt->hdr) + payload_len); |
| 218 | added = true; |
| 219 | |
| 220 | pkt->off += payload_len; |
| 221 | total_len += payload_len; |
| 222 | |
| 223 | /* If we didn't send all the payload we can requeue the packet |
| 224 | * to send it with the next available buffer. |
| 225 | */ |
| 226 | if (pkt->off < pkt->len) { |
| 227 | if (restore_flag) |
| 228 | pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR); |
| 229 | |
| 230 | /* We are queueing the same virtio_vsock_pkt to handle |
| 231 | * the remaining bytes, and we want to deliver it |
| 232 | * to monitoring devices in the next iteration. |
| 233 | */ |
| 234 | pkt->tap_delivered = false; |
| 235 | |
| 236 | spin_lock_bh(&vsock->send_pkt_list_lock); |
| 237 | list_add(&pkt->list, &vsock->send_pkt_list); |
| 238 | spin_unlock_bh(&vsock->send_pkt_list_lock); |
| 239 | } else { |
| 240 | if (pkt->reply) { |
| 241 | int val; |
| 242 | |
| 243 | val = atomic_dec_return(&vsock->queued_replies); |
| 244 | |
| 245 | /* Do we have resources to resume tx |
| 246 | * processing? |
| 247 | */ |
| 248 | if (val + 1 == tx_vq->num) |
| 249 | restart_tx = true; |
| 250 | } |
| 251 | |
| 252 | virtio_transport_free_pkt(pkt); |
| 253 | } |
| 254 | } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len))); |
| 255 | if (added) |
| 256 | vhost_signal(&vsock->dev, vq); |
| 257 | |
| 258 | out: |
| 259 | mutex_unlock(&vq->mutex); |
| 260 | |
| 261 | if (restart_tx) |
| 262 | vhost_poll_queue(&tx_vq->poll); |
| 263 | } |
| 264 | |
| 265 | static void vhost_transport_send_pkt_work(struct vhost_work *work) |
| 266 | { |
| 267 | struct vhost_virtqueue *vq; |
| 268 | struct vhost_vsock *vsock; |
| 269 | |
| 270 | vsock = container_of(work, struct vhost_vsock, send_pkt_work); |
| 271 | vq = &vsock->vqs[VSOCK_VQ_RX]; |
| 272 | |
| 273 | vhost_transport_do_send_pkt(vsock, vq); |
| 274 | } |
| 275 | |
| 276 | static int |
| 277 | vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt) |
| 278 | { |
| 279 | struct vhost_vsock *vsock; |
| 280 | int len = pkt->len; |
| 281 | |
| 282 | rcu_read_lock(); |
| 283 | |
| 284 | /* Find the vhost_vsock according to guest context id */ |
| 285 | vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid)); |
| 286 | if (!vsock) { |
| 287 | rcu_read_unlock(); |
| 288 | virtio_transport_free_pkt(pkt); |
| 289 | return -ENODEV; |
| 290 | } |
| 291 | |
| 292 | if (pkt->reply) |
| 293 | atomic_inc(&vsock->queued_replies); |
| 294 | |
| 295 | spin_lock_bh(&vsock->send_pkt_list_lock); |
| 296 | list_add_tail(&pkt->list, &vsock->send_pkt_list); |
| 297 | spin_unlock_bh(&vsock->send_pkt_list_lock); |
| 298 | |
| 299 | vhost_work_queue(&vsock->dev, &vsock->send_pkt_work); |
| 300 | |
| 301 | rcu_read_unlock(); |
| 302 | return len; |
| 303 | } |
| 304 | |
| 305 | static int |
| 306 | vhost_transport_cancel_pkt(struct vsock_sock *vsk) |
| 307 | { |
| 308 | struct vhost_vsock *vsock; |
| 309 | struct virtio_vsock_pkt *pkt, *n; |
| 310 | int cnt = 0; |
| 311 | int ret = -ENODEV; |
| 312 | LIST_HEAD(freeme); |
| 313 | |
| 314 | rcu_read_lock(); |
| 315 | |
| 316 | /* Find the vhost_vsock according to guest context id */ |
| 317 | vsock = vhost_vsock_get(vsk->remote_addr.svm_cid); |
| 318 | if (!vsock) |
| 319 | goto out; |
| 320 | |
| 321 | spin_lock_bh(&vsock->send_pkt_list_lock); |
| 322 | list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) { |
| 323 | if (pkt->vsk != vsk) |
| 324 | continue; |
| 325 | list_move(&pkt->list, &freeme); |
| 326 | } |
| 327 | spin_unlock_bh(&vsock->send_pkt_list_lock); |
| 328 | |
| 329 | list_for_each_entry_safe(pkt, n, &freeme, list) { |
| 330 | if (pkt->reply) |
| 331 | cnt++; |
| 332 | list_del(&pkt->list); |
| 333 | virtio_transport_free_pkt(pkt); |
| 334 | } |
| 335 | |
| 336 | if (cnt) { |
| 337 | struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX]; |
| 338 | int new_cnt; |
| 339 | |
| 340 | new_cnt = atomic_sub_return(cnt, &vsock->queued_replies); |
| 341 | if (new_cnt + cnt >= tx_vq->num && new_cnt < tx_vq->num) |
| 342 | vhost_poll_queue(&tx_vq->poll); |
| 343 | } |
| 344 | |
| 345 | ret = 0; |
| 346 | out: |
| 347 | rcu_read_unlock(); |
| 348 | return ret; |
| 349 | } |
| 350 | |
| 351 | static struct virtio_vsock_pkt * |
| 352 | vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq, |
| 353 | unsigned int out, unsigned int in) |
| 354 | { |
| 355 | struct virtio_vsock_pkt *pkt; |
| 356 | struct iov_iter iov_iter; |
| 357 | size_t nbytes; |
| 358 | size_t len; |
| 359 | |
| 360 | if (in != 0) { |
| 361 | vq_err(vq, "Expected 0 input buffers, got %u\n", in); |
| 362 | return NULL; |
| 363 | } |
| 364 | |
| 365 | pkt = kzalloc(sizeof(*pkt), GFP_KERNEL); |
| 366 | if (!pkt) |
| 367 | return NULL; |
| 368 | |
| 369 | len = iov_length(vq->iov, out); |
| 370 | iov_iter_init(&iov_iter, WRITE, vq->iov, out, len); |
| 371 | |
| 372 | nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter); |
| 373 | if (nbytes != sizeof(pkt->hdr)) { |
| 374 | vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n", |
| 375 | sizeof(pkt->hdr), nbytes); |
| 376 | kfree(pkt); |
| 377 | return NULL; |
| 378 | } |
| 379 | |
| 380 | pkt->len = le32_to_cpu(pkt->hdr.len); |
| 381 | |
| 382 | /* No payload */ |
| 383 | if (!pkt->len) |
| 384 | return pkt; |
| 385 | |
| 386 | /* The pkt is too big */ |
| 387 | if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) { |
| 388 | kfree(pkt); |
| 389 | return NULL; |
| 390 | } |
| 391 | |
| 392 | pkt->buf = kmalloc(pkt->len, GFP_KERNEL); |
| 393 | if (!pkt->buf) { |
| 394 | kfree(pkt); |
| 395 | return NULL; |
| 396 | } |
| 397 | |
| 398 | pkt->buf_len = pkt->len; |
| 399 | |
| 400 | nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter); |
| 401 | if (nbytes != pkt->len) { |
| 402 | vq_err(vq, "Expected %u byte payload, got %zu bytes\n", |
| 403 | pkt->len, nbytes); |
| 404 | virtio_transport_free_pkt(pkt); |
| 405 | return NULL; |
| 406 | } |
| 407 | |
| 408 | return pkt; |
| 409 | } |
| 410 | |
| 411 | /* Is there space left for replies to rx packets? */ |
| 412 | static bool vhost_vsock_more_replies(struct vhost_vsock *vsock) |
| 413 | { |
| 414 | struct vhost_virtqueue *vq = &vsock->vqs[VSOCK_VQ_TX]; |
| 415 | int val; |
| 416 | |
| 417 | smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */ |
| 418 | val = atomic_read(&vsock->queued_replies); |
| 419 | |
| 420 | return val < vq->num; |
| 421 | } |
| 422 | |
| 423 | static bool vhost_transport_seqpacket_allow(u32 remote_cid); |
| 424 | |
| 425 | static struct virtio_transport vhost_transport = { |
| 426 | .transport = { |
| 427 | .module = THIS_MODULE, |
| 428 | |
| 429 | .get_local_cid = vhost_transport_get_local_cid, |
| 430 | |
| 431 | .init = virtio_transport_do_socket_init, |
| 432 | .destruct = virtio_transport_destruct, |
| 433 | .release = virtio_transport_release, |
| 434 | .connect = virtio_transport_connect, |
| 435 | .shutdown = virtio_transport_shutdown, |
| 436 | .cancel_pkt = vhost_transport_cancel_pkt, |
| 437 | |
| 438 | .dgram_enqueue = virtio_transport_dgram_enqueue, |
| 439 | .dgram_dequeue = virtio_transport_dgram_dequeue, |
| 440 | .dgram_bind = virtio_transport_dgram_bind, |
| 441 | .dgram_allow = virtio_transport_dgram_allow, |
| 442 | |
| 443 | .stream_enqueue = virtio_transport_stream_enqueue, |
| 444 | .stream_dequeue = virtio_transport_stream_dequeue, |
| 445 | .stream_has_data = virtio_transport_stream_has_data, |
| 446 | .stream_has_space = virtio_transport_stream_has_space, |
| 447 | .stream_rcvhiwat = virtio_transport_stream_rcvhiwat, |
| 448 | .stream_is_active = virtio_transport_stream_is_active, |
| 449 | .stream_allow = virtio_transport_stream_allow, |
| 450 | |
| 451 | .seqpacket_dequeue = virtio_transport_seqpacket_dequeue, |
| 452 | .seqpacket_enqueue = virtio_transport_seqpacket_enqueue, |
| 453 | .seqpacket_allow = vhost_transport_seqpacket_allow, |
| 454 | .seqpacket_has_data = virtio_transport_seqpacket_has_data, |
| 455 | |
| 456 | .notify_poll_in = virtio_transport_notify_poll_in, |
| 457 | .notify_poll_out = virtio_transport_notify_poll_out, |
| 458 | .notify_recv_init = virtio_transport_notify_recv_init, |
| 459 | .notify_recv_pre_block = virtio_transport_notify_recv_pre_block, |
| 460 | .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue, |
| 461 | .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue, |
| 462 | .notify_send_init = virtio_transport_notify_send_init, |
| 463 | .notify_send_pre_block = virtio_transport_notify_send_pre_block, |
| 464 | .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, |
| 465 | .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, |
| 466 | .notify_buffer_size = virtio_transport_notify_buffer_size, |
| 467 | |
| 468 | }, |
| 469 | |
| 470 | .send_pkt = vhost_transport_send_pkt, |
| 471 | }; |
| 472 | |
| 473 | static bool vhost_transport_seqpacket_allow(u32 remote_cid) |
| 474 | { |
| 475 | struct vhost_vsock *vsock; |
| 476 | bool seqpacket_allow = false; |
| 477 | |
| 478 | rcu_read_lock(); |
| 479 | vsock = vhost_vsock_get(remote_cid); |
| 480 | |
| 481 | if (vsock) |
| 482 | seqpacket_allow = vsock->seqpacket_allow; |
| 483 | |
| 484 | rcu_read_unlock(); |
| 485 | |
| 486 | return seqpacket_allow; |
| 487 | } |
| 488 | |
| 489 | static void vhost_vsock_handle_tx_kick(struct vhost_work *work) |
| 490 | { |
| 491 | struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, |
| 492 | poll.work); |
| 493 | struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock, |
| 494 | dev); |
| 495 | struct virtio_vsock_pkt *pkt; |
| 496 | int head, pkts = 0, total_len = 0; |
| 497 | unsigned int out, in; |
| 498 | bool added = false; |
| 499 | |
| 500 | mutex_lock(&vq->mutex); |
| 501 | |
| 502 | if (!vhost_vq_get_backend(vq)) |
| 503 | goto out; |
| 504 | |
| 505 | if (!vq_meta_prefetch(vq)) |
| 506 | goto out; |
| 507 | |
| 508 | vhost_disable_notify(&vsock->dev, vq); |
| 509 | do { |
| 510 | u32 len; |
| 511 | |
| 512 | if (!vhost_vsock_more_replies(vsock)) { |
| 513 | /* Stop tx until the device processes already |
| 514 | * pending replies. Leave tx virtqueue |
| 515 | * callbacks disabled. |
| 516 | */ |
| 517 | goto no_more_replies; |
| 518 | } |
| 519 | |
| 520 | head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), |
| 521 | &out, &in, NULL, NULL); |
| 522 | if (head < 0) |
| 523 | break; |
| 524 | |
| 525 | if (head == vq->num) { |
| 526 | if (unlikely(vhost_enable_notify(&vsock->dev, vq))) { |
| 527 | vhost_disable_notify(&vsock->dev, vq); |
| 528 | continue; |
| 529 | } |
| 530 | break; |
| 531 | } |
| 532 | |
| 533 | pkt = vhost_vsock_alloc_pkt(vq, out, in); |
| 534 | if (!pkt) { |
| 535 | vq_err(vq, "Faulted on pkt\n"); |
| 536 | continue; |
| 537 | } |
| 538 | |
| 539 | len = pkt->len; |
| 540 | |
| 541 | /* Deliver to monitoring devices all received packets */ |
| 542 | virtio_transport_deliver_tap_pkt(pkt); |
| 543 | |
| 544 | /* Only accept correctly addressed packets */ |
| 545 | if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid && |
| 546 | le64_to_cpu(pkt->hdr.dst_cid) == |
| 547 | vhost_transport_get_local_cid()) |
| 548 | virtio_transport_recv_pkt(&vhost_transport, pkt); |
| 549 | else |
| 550 | virtio_transport_free_pkt(pkt); |
| 551 | |
| 552 | len += sizeof(pkt->hdr); |
| 553 | vhost_add_used(vq, head, len); |
| 554 | total_len += len; |
| 555 | added = true; |
| 556 | } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len))); |
| 557 | |
| 558 | no_more_replies: |
| 559 | if (added) |
| 560 | vhost_signal(&vsock->dev, vq); |
| 561 | |
| 562 | out: |
| 563 | mutex_unlock(&vq->mutex); |
| 564 | } |
| 565 | |
| 566 | static void vhost_vsock_handle_rx_kick(struct vhost_work *work) |
| 567 | { |
| 568 | struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, |
| 569 | poll.work); |
| 570 | struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock, |
| 571 | dev); |
| 572 | |
| 573 | vhost_transport_do_send_pkt(vsock, vq); |
| 574 | } |
| 575 | |
| 576 | static int vhost_vsock_start(struct vhost_vsock *vsock) |
| 577 | { |
| 578 | struct vhost_virtqueue *vq; |
| 579 | size_t i; |
| 580 | int ret; |
| 581 | |
| 582 | mutex_lock(&vsock->dev.mutex); |
| 583 | |
| 584 | ret = vhost_dev_check_owner(&vsock->dev); |
| 585 | if (ret) |
| 586 | goto err; |
| 587 | |
| 588 | for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { |
| 589 | vq = &vsock->vqs[i]; |
| 590 | |
| 591 | mutex_lock(&vq->mutex); |
| 592 | |
| 593 | if (!vhost_vq_access_ok(vq)) { |
| 594 | ret = -EFAULT; |
| 595 | goto err_vq; |
| 596 | } |
| 597 | |
| 598 | if (!vhost_vq_get_backend(vq)) { |
| 599 | vhost_vq_set_backend(vq, vsock); |
| 600 | ret = vhost_vq_init_access(vq); |
| 601 | if (ret) |
| 602 | goto err_vq; |
| 603 | } |
| 604 | |
| 605 | mutex_unlock(&vq->mutex); |
| 606 | } |
| 607 | |
| 608 | /* Some packets may have been queued before the device was started, |
| 609 | * let's kick the send worker to send them. |
| 610 | */ |
| 611 | vhost_work_queue(&vsock->dev, &vsock->send_pkt_work); |
| 612 | |
| 613 | mutex_unlock(&vsock->dev.mutex); |
| 614 | return 0; |
| 615 | |
| 616 | err_vq: |
| 617 | vhost_vq_set_backend(vq, NULL); |
| 618 | mutex_unlock(&vq->mutex); |
| 619 | |
| 620 | for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { |
| 621 | vq = &vsock->vqs[i]; |
| 622 | |
| 623 | mutex_lock(&vq->mutex); |
| 624 | vhost_vq_set_backend(vq, NULL); |
| 625 | mutex_unlock(&vq->mutex); |
| 626 | } |
| 627 | err: |
| 628 | mutex_unlock(&vsock->dev.mutex); |
| 629 | return ret; |
| 630 | } |
| 631 | |
| 632 | static int vhost_vsock_stop(struct vhost_vsock *vsock) |
| 633 | { |
| 634 | size_t i; |
| 635 | int ret; |
| 636 | |
| 637 | mutex_lock(&vsock->dev.mutex); |
| 638 | |
| 639 | ret = vhost_dev_check_owner(&vsock->dev); |
| 640 | if (ret) |
| 641 | goto err; |
| 642 | |
| 643 | for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { |
| 644 | struct vhost_virtqueue *vq = &vsock->vqs[i]; |
| 645 | |
| 646 | mutex_lock(&vq->mutex); |
| 647 | vhost_vq_set_backend(vq, NULL); |
| 648 | mutex_unlock(&vq->mutex); |
| 649 | } |
| 650 | |
| 651 | err: |
| 652 | mutex_unlock(&vsock->dev.mutex); |
| 653 | return ret; |
| 654 | } |
| 655 | |
| 656 | static void vhost_vsock_free(struct vhost_vsock *vsock) |
| 657 | { |
| 658 | kvfree(vsock); |
| 659 | } |
| 660 | |
| 661 | static int vhost_vsock_dev_open(struct inode *inode, struct file *file) |
| 662 | { |
| 663 | struct vhost_virtqueue **vqs; |
| 664 | struct vhost_vsock *vsock; |
| 665 | int ret; |
| 666 | |
| 667 | /* This struct is large and allocation could fail, fall back to vmalloc |
| 668 | * if there is no other way. |
| 669 | */ |
| 670 | vsock = kvmalloc(sizeof(*vsock), GFP_KERNEL | __GFP_RETRY_MAYFAIL); |
| 671 | if (!vsock) |
| 672 | return -ENOMEM; |
| 673 | |
| 674 | vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL); |
| 675 | if (!vqs) { |
| 676 | ret = -ENOMEM; |
| 677 | goto out; |
| 678 | } |
| 679 | |
| 680 | vsock->guest_cid = 0; /* no CID assigned yet */ |
| 681 | |
| 682 | atomic_set(&vsock->queued_replies, 0); |
| 683 | |
| 684 | vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX]; |
| 685 | vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX]; |
| 686 | vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick; |
| 687 | vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick; |
| 688 | |
| 689 | vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs), |
| 690 | UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT, |
| 691 | VHOST_VSOCK_WEIGHT, true, NULL); |
| 692 | |
| 693 | file->private_data = vsock; |
| 694 | spin_lock_init(&vsock->send_pkt_list_lock); |
| 695 | INIT_LIST_HEAD(&vsock->send_pkt_list); |
| 696 | vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work); |
| 697 | return 0; |
| 698 | |
| 699 | out: |
| 700 | vhost_vsock_free(vsock); |
| 701 | return ret; |
| 702 | } |
| 703 | |
| 704 | static void vhost_vsock_flush(struct vhost_vsock *vsock) |
| 705 | { |
| 706 | int i; |
| 707 | |
| 708 | for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) |
| 709 | if (vsock->vqs[i].handle_kick) |
| 710 | vhost_poll_flush(&vsock->vqs[i].poll); |
| 711 | vhost_work_flush(&vsock->dev, &vsock->send_pkt_work); |
| 712 | } |
| 713 | |
| 714 | static void vhost_vsock_reset_orphans(struct sock *sk) |
| 715 | { |
| 716 | struct vsock_sock *vsk = vsock_sk(sk); |
| 717 | |
| 718 | /* vmci_transport.c doesn't take sk_lock here either. At least we're |
| 719 | * under vsock_table_lock so the sock cannot disappear while we're |
| 720 | * executing. |
| 721 | */ |
| 722 | |
| 723 | /* If the peer is still valid, no need to reset connection */ |
| 724 | if (vhost_vsock_get(vsk->remote_addr.svm_cid)) |
| 725 | return; |
| 726 | |
| 727 | /* If the close timeout is pending, let it expire. This avoids races |
| 728 | * with the timeout callback. |
| 729 | */ |
| 730 | if (vsk->close_work_scheduled) |
| 731 | return; |
| 732 | |
| 733 | sock_set_flag(sk, SOCK_DONE); |
| 734 | vsk->peer_shutdown = SHUTDOWN_MASK; |
| 735 | sk->sk_state = SS_UNCONNECTED; |
| 736 | sk->sk_err = ECONNRESET; |
| 737 | sk->sk_error_report(sk); |
| 738 | } |
| 739 | |
| 740 | static int vhost_vsock_dev_release(struct inode *inode, struct file *file) |
| 741 | { |
| 742 | struct vhost_vsock *vsock = file->private_data; |
| 743 | |
| 744 | mutex_lock(&vhost_vsock_mutex); |
| 745 | if (vsock->guest_cid) |
| 746 | hash_del_rcu(&vsock->hash); |
| 747 | mutex_unlock(&vhost_vsock_mutex); |
| 748 | |
| 749 | /* Wait for other CPUs to finish using vsock */ |
| 750 | synchronize_rcu(); |
| 751 | |
| 752 | /* Iterating over all connections for all CIDs to find orphans is |
| 753 | * inefficient. Room for improvement here. */ |
| 754 | vsock_for_each_connected_socket(vhost_vsock_reset_orphans); |
| 755 | |
| 756 | vhost_vsock_stop(vsock); |
| 757 | vhost_vsock_flush(vsock); |
| 758 | vhost_dev_stop(&vsock->dev); |
| 759 | |
| 760 | spin_lock_bh(&vsock->send_pkt_list_lock); |
| 761 | while (!list_empty(&vsock->send_pkt_list)) { |
| 762 | struct virtio_vsock_pkt *pkt; |
| 763 | |
| 764 | pkt = list_first_entry(&vsock->send_pkt_list, |
| 765 | struct virtio_vsock_pkt, list); |
| 766 | list_del_init(&pkt->list); |
| 767 | virtio_transport_free_pkt(pkt); |
| 768 | } |
| 769 | spin_unlock_bh(&vsock->send_pkt_list_lock); |
| 770 | |
| 771 | vhost_dev_cleanup(&vsock->dev); |
| 772 | kfree(vsock->dev.vqs); |
| 773 | vhost_vsock_free(vsock); |
| 774 | return 0; |
| 775 | } |
| 776 | |
| 777 | static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid) |
| 778 | { |
| 779 | struct vhost_vsock *other; |
| 780 | |
| 781 | /* Refuse reserved CIDs */ |
| 782 | if (guest_cid <= VMADDR_CID_HOST || |
| 783 | guest_cid == U32_MAX) |
| 784 | return -EINVAL; |
| 785 | |
| 786 | /* 64-bit CIDs are not yet supported */ |
| 787 | if (guest_cid > U32_MAX) |
| 788 | return -EINVAL; |
| 789 | |
| 790 | /* Refuse if CID is assigned to the guest->host transport (i.e. nested |
| 791 | * VM), to make the loopback work. |
| 792 | */ |
| 793 | if (vsock_find_cid(guest_cid)) |
| 794 | return -EADDRINUSE; |
| 795 | |
| 796 | /* Refuse if CID is already in use */ |
| 797 | mutex_lock(&vhost_vsock_mutex); |
| 798 | other = vhost_vsock_get(guest_cid); |
| 799 | if (other && other != vsock) { |
| 800 | mutex_unlock(&vhost_vsock_mutex); |
| 801 | return -EADDRINUSE; |
| 802 | } |
| 803 | |
| 804 | if (vsock->guest_cid) |
| 805 | hash_del_rcu(&vsock->hash); |
| 806 | |
| 807 | vsock->guest_cid = guest_cid; |
| 808 | hash_add_rcu(vhost_vsock_hash, &vsock->hash, vsock->guest_cid); |
| 809 | mutex_unlock(&vhost_vsock_mutex); |
| 810 | |
| 811 | return 0; |
| 812 | } |
| 813 | |
| 814 | static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features) |
| 815 | { |
| 816 | struct vhost_virtqueue *vq; |
| 817 | int i; |
| 818 | |
| 819 | if (features & ~VHOST_VSOCK_FEATURES) |
| 820 | return -EOPNOTSUPP; |
| 821 | |
| 822 | mutex_lock(&vsock->dev.mutex); |
| 823 | if ((features & (1 << VHOST_F_LOG_ALL)) && |
| 824 | !vhost_log_access_ok(&vsock->dev)) { |
| 825 | goto err; |
| 826 | } |
| 827 | |
| 828 | if ((features & (1ULL << VIRTIO_F_ACCESS_PLATFORM))) { |
| 829 | if (vhost_init_device_iotlb(&vsock->dev, true)) |
| 830 | goto err; |
| 831 | } |
| 832 | |
| 833 | if (features & (1ULL << VIRTIO_VSOCK_F_SEQPACKET)) |
| 834 | vsock->seqpacket_allow = true; |
| 835 | |
| 836 | for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { |
| 837 | vq = &vsock->vqs[i]; |
| 838 | mutex_lock(&vq->mutex); |
| 839 | vq->acked_features = features; |
| 840 | mutex_unlock(&vq->mutex); |
| 841 | } |
| 842 | mutex_unlock(&vsock->dev.mutex); |
| 843 | return 0; |
| 844 | |
| 845 | err: |
| 846 | mutex_unlock(&vsock->dev.mutex); |
| 847 | return -EFAULT; |
| 848 | } |
| 849 | |
| 850 | static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl, |
| 851 | unsigned long arg) |
| 852 | { |
| 853 | struct vhost_vsock *vsock = f->private_data; |
| 854 | void __user *argp = (void __user *)arg; |
| 855 | u64 guest_cid; |
| 856 | u64 features; |
| 857 | int start; |
| 858 | int r; |
| 859 | |
| 860 | switch (ioctl) { |
| 861 | case VHOST_VSOCK_SET_GUEST_CID: |
| 862 | if (copy_from_user(&guest_cid, argp, sizeof(guest_cid))) |
| 863 | return -EFAULT; |
| 864 | return vhost_vsock_set_cid(vsock, guest_cid); |
| 865 | case VHOST_VSOCK_SET_RUNNING: |
| 866 | if (copy_from_user(&start, argp, sizeof(start))) |
| 867 | return -EFAULT; |
| 868 | if (start) |
| 869 | return vhost_vsock_start(vsock); |
| 870 | else |
| 871 | return vhost_vsock_stop(vsock); |
| 872 | case VHOST_GET_FEATURES: |
| 873 | features = VHOST_VSOCK_FEATURES; |
| 874 | if (copy_to_user(argp, &features, sizeof(features))) |
| 875 | return -EFAULT; |
| 876 | return 0; |
| 877 | case VHOST_SET_FEATURES: |
| 878 | if (copy_from_user(&features, argp, sizeof(features))) |
| 879 | return -EFAULT; |
| 880 | return vhost_vsock_set_features(vsock, features); |
| 881 | case VHOST_GET_BACKEND_FEATURES: |
| 882 | features = VHOST_VSOCK_BACKEND_FEATURES; |
| 883 | if (copy_to_user(argp, &features, sizeof(features))) |
| 884 | return -EFAULT; |
| 885 | return 0; |
| 886 | case VHOST_SET_BACKEND_FEATURES: |
| 887 | if (copy_from_user(&features, argp, sizeof(features))) |
| 888 | return -EFAULT; |
| 889 | if (features & ~VHOST_VSOCK_BACKEND_FEATURES) |
| 890 | return -EOPNOTSUPP; |
| 891 | vhost_set_backend_features(&vsock->dev, features); |
| 892 | return 0; |
| 893 | default: |
| 894 | mutex_lock(&vsock->dev.mutex); |
| 895 | r = vhost_dev_ioctl(&vsock->dev, ioctl, argp); |
| 896 | if (r == -ENOIOCTLCMD) |
| 897 | r = vhost_vring_ioctl(&vsock->dev, ioctl, argp); |
| 898 | else |
| 899 | vhost_vsock_flush(vsock); |
| 900 | mutex_unlock(&vsock->dev.mutex); |
| 901 | return r; |
| 902 | } |
| 903 | } |
| 904 | |
| 905 | static ssize_t vhost_vsock_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) |
| 906 | { |
| 907 | struct file *file = iocb->ki_filp; |
| 908 | struct vhost_vsock *vsock = file->private_data; |
| 909 | struct vhost_dev *dev = &vsock->dev; |
| 910 | int noblock = file->f_flags & O_NONBLOCK; |
| 911 | |
| 912 | return vhost_chr_read_iter(dev, to, noblock); |
| 913 | } |
| 914 | |
| 915 | static ssize_t vhost_vsock_chr_write_iter(struct kiocb *iocb, |
| 916 | struct iov_iter *from) |
| 917 | { |
| 918 | struct file *file = iocb->ki_filp; |
| 919 | struct vhost_vsock *vsock = file->private_data; |
| 920 | struct vhost_dev *dev = &vsock->dev; |
| 921 | |
| 922 | return vhost_chr_write_iter(dev, from); |
| 923 | } |
| 924 | |
| 925 | static __poll_t vhost_vsock_chr_poll(struct file *file, poll_table *wait) |
| 926 | { |
| 927 | struct vhost_vsock *vsock = file->private_data; |
| 928 | struct vhost_dev *dev = &vsock->dev; |
| 929 | |
| 930 | return vhost_chr_poll(file, dev, wait); |
| 931 | } |
| 932 | |
| 933 | static const struct file_operations vhost_vsock_fops = { |
| 934 | .owner = THIS_MODULE, |
| 935 | .open = vhost_vsock_dev_open, |
| 936 | .release = vhost_vsock_dev_release, |
| 937 | .llseek = noop_llseek, |
| 938 | .unlocked_ioctl = vhost_vsock_dev_ioctl, |
| 939 | .compat_ioctl = compat_ptr_ioctl, |
| 940 | .read_iter = vhost_vsock_chr_read_iter, |
| 941 | .write_iter = vhost_vsock_chr_write_iter, |
| 942 | .poll = vhost_vsock_chr_poll, |
| 943 | }; |
| 944 | |
| 945 | static struct miscdevice vhost_vsock_misc = { |
| 946 | .minor = VHOST_VSOCK_MINOR, |
| 947 | .name = "vhost-vsock", |
| 948 | .fops = &vhost_vsock_fops, |
| 949 | }; |
| 950 | |
| 951 | static int __init vhost_vsock_init(void) |
| 952 | { |
| 953 | int ret; |
| 954 | |
| 955 | ret = vsock_core_register(&vhost_transport.transport, |
| 956 | VSOCK_TRANSPORT_F_H2G); |
| 957 | if (ret < 0) |
| 958 | return ret; |
| 959 | return misc_register(&vhost_vsock_misc); |
| 960 | }; |
| 961 | |
| 962 | static void __exit vhost_vsock_exit(void) |
| 963 | { |
| 964 | misc_deregister(&vhost_vsock_misc); |
| 965 | vsock_core_unregister(&vhost_transport.transport); |
| 966 | }; |
| 967 | |
| 968 | module_init(vhost_vsock_init); |
| 969 | module_exit(vhost_vsock_exit); |
| 970 | MODULE_LICENSE("GPL v2"); |
| 971 | MODULE_AUTHOR("Asias He"); |
| 972 | MODULE_DESCRIPTION("vhost transport for vsock "); |
| 973 | MODULE_ALIAS_MISCDEV(VHOST_VSOCK_MINOR); |
| 974 | MODULE_ALIAS("devname:vhost-vsock"); |