virtio_transport.c 19.4 KB
Newer Older
1
// SPDX-License-Identifier: GPL-2.0-only
A
Asias He 已提交
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
/*
 * virtio transport for vsock
 *
 * Copyright (C) 2013-2015 Red Hat, Inc.
 * Author: Asias He <asias@redhat.com>
 *         Stefan Hajnoczi <stefanha@redhat.com>
 *
 * Some of the code is take from Gerd Hoffmann <kraxel@redhat.com>'s
 * early virtio-vsock proof-of-concept bits.
 */
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/atomic.h>
#include <linux/virtio.h>
#include <linux/virtio_ids.h>
#include <linux/virtio_config.h>
#include <linux/virtio_vsock.h>
#include <net/sock.h>
#include <linux/mutex.h>
#include <net/af_vsock.h>

static struct workqueue_struct *virtio_vsock_workqueue;
static struct virtio_vsock *the_virtio_vsock;
static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */

struct virtio_vsock {
	struct virtio_device *vdev;
	struct virtqueue *vqs[VSOCK_VQ_MAX];

	/* Virtqueue processing is deferred to a workqueue */
	struct work_struct tx_work;
	struct work_struct rx_work;
	struct work_struct event_work;

	/* The following fields are protected by tx_lock.  vqs[VSOCK_VQ_TX]
	 * must be accessed with tx_lock held.
	 */
	struct mutex tx_lock;
41
	bool tx_run;
A
Asias He 已提交
42 43 44 45 46

	struct work_struct send_pkt_work;
	spinlock_t send_pkt_list_lock;
	struct list_head send_pkt_list;

47 48 49 50
	struct work_struct loopback_work;
	spinlock_t loopback_list_lock; /* protects loopback_list */
	struct list_head loopback_list;

A
Asias He 已提交
51 52 53 54 55 56
	atomic_t queued_replies;

	/* The following fields are protected by rx_lock.  vqs[VSOCK_VQ_RX]
	 * must be accessed with rx_lock held.
	 */
	struct mutex rx_lock;
57
	bool rx_run;
A
Asias He 已提交
58 59 60 61 62 63 64
	int rx_buf_nr;
	int rx_buf_max_nr;

	/* The following fields are protected by event_lock.
	 * vqs[VSOCK_VQ_EVENT] must be accessed with event_lock held.
	 */
	struct mutex event_lock;
65
	bool event_run;
A
Asias He 已提交
66 67 68 69 70 71 72
	struct virtio_vsock_event event_list[8];

	u32 guest_cid;
};

static u32 virtio_transport_get_local_cid(void)
{
73 74
	struct virtio_vsock *vsock;
	u32 ret;
A
Asias He 已提交
75

76 77 78 79 80 81
	rcu_read_lock();
	vsock = rcu_dereference(the_virtio_vsock);
	if (!vsock) {
		ret = VMADDR_CID_ANY;
		goto out_rcu;
	}
82

83 84 85 86
	ret = vsock->guest_cid;
out_rcu:
	rcu_read_unlock();
	return ret;
A
Asias He 已提交
87 88
}

89 90 91 92 93 94 95 96 97 98 99 100 101 102
static int virtio_transport_send_pkt_loopback(struct virtio_vsock *vsock,
					      struct virtio_vsock_pkt *pkt)
{
	int len = pkt->len;

	spin_lock_bh(&vsock->loopback_list_lock);
	list_add_tail(&pkt->list, &vsock->loopback_list);
	spin_unlock_bh(&vsock->loopback_list_lock);

	queue_work(virtio_vsock_workqueue, &vsock->loopback_work);

	return len;
}

A
Asias He 已提交
103 104 105 106 107 108 109 110 111 112 113
static void
virtio_transport_send_pkt_work(struct work_struct *work)
{
	struct virtio_vsock *vsock =
		container_of(work, struct virtio_vsock, send_pkt_work);
	struct virtqueue *vq;
	bool added = false;
	bool restart_rx = false;

	mutex_lock(&vsock->tx_lock);

114 115 116
	if (!vsock->tx_run)
		goto out;

A
Asias He 已提交
117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135
	vq = vsock->vqs[VSOCK_VQ_TX];

	for (;;) {
		struct virtio_vsock_pkt *pkt;
		struct scatterlist hdr, buf, *sgs[2];
		int ret, in_sg = 0, out_sg = 0;
		bool reply;

		spin_lock_bh(&vsock->send_pkt_list_lock);
		if (list_empty(&vsock->send_pkt_list)) {
			spin_unlock_bh(&vsock->send_pkt_list_lock);
			break;
		}

		pkt = list_first_entry(&vsock->send_pkt_list,
				       struct virtio_vsock_pkt, list);
		list_del_init(&pkt->list);
		spin_unlock_bh(&vsock->send_pkt_list_lock);

136 137
		virtio_transport_deliver_tap_pkt(pkt);

A
Asias He 已提交
138 139 140 141 142 143 144 145 146 147
		reply = pkt->reply;

		sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
		sgs[out_sg++] = &hdr;
		if (pkt->buf) {
			sg_init_one(&buf, pkt->buf, pkt->len);
			sgs[out_sg++] = &buf;
		}

		ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt, GFP_KERNEL);
148 149 150
		/* Usually this means that there is no more space available in
		 * the vq
		 */
A
Asias He 已提交
151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174
		if (ret < 0) {
			spin_lock_bh(&vsock->send_pkt_list_lock);
			list_add(&pkt->list, &vsock->send_pkt_list);
			spin_unlock_bh(&vsock->send_pkt_list_lock);
			break;
		}

		if (reply) {
			struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
			int val;

			val = atomic_dec_return(&vsock->queued_replies);

			/* Do we now have resources to resume rx processing? */
			if (val + 1 == virtqueue_get_vring_size(rx_vq))
				restart_rx = true;
		}

		added = true;
	}

	if (added)
		virtqueue_kick(vq);

175
out:
A
Asias He 已提交
176 177 178 179 180 181 182 183 184 185 186 187
	mutex_unlock(&vsock->tx_lock);

	if (restart_rx)
		queue_work(virtio_vsock_workqueue, &vsock->rx_work);
}

static int
virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt)
{
	struct virtio_vsock *vsock;
	int len = pkt->len;

188 189
	rcu_read_lock();
	vsock = rcu_dereference(the_virtio_vsock);
A
Asias He 已提交
190 191
	if (!vsock) {
		virtio_transport_free_pkt(pkt);
192 193
		len = -ENODEV;
		goto out_rcu;
A
Asias He 已提交
194 195
	}

196 197 198 199
	if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid) {
		len = virtio_transport_send_pkt_loopback(vsock, pkt);
		goto out_rcu;
	}
200

A
Asias He 已提交
201 202 203 204 205 206 207 208
	if (pkt->reply)
		atomic_inc(&vsock->queued_replies);

	spin_lock_bh(&vsock->send_pkt_list_lock);
	list_add_tail(&pkt->list, &vsock->send_pkt_list);
	spin_unlock_bh(&vsock->send_pkt_list_lock);

	queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
209 210 211

out_rcu:
	rcu_read_unlock();
A
Asias He 已提交
212 213 214
	return len;
}

P
Peng Tao 已提交
215 216 217 218 219
static int
virtio_transport_cancel_pkt(struct vsock_sock *vsk)
{
	struct virtio_vsock *vsock;
	struct virtio_vsock_pkt *pkt, *n;
220
	int cnt = 0, ret;
P
Peng Tao 已提交
221 222
	LIST_HEAD(freeme);

223 224
	rcu_read_lock();
	vsock = rcu_dereference(the_virtio_vsock);
P
Peng Tao 已提交
225
	if (!vsock) {
226 227
		ret = -ENODEV;
		goto out_rcu;
P
Peng Tao 已提交
228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254
	}

	spin_lock_bh(&vsock->send_pkt_list_lock);
	list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
		if (pkt->vsk != vsk)
			continue;
		list_move(&pkt->list, &freeme);
	}
	spin_unlock_bh(&vsock->send_pkt_list_lock);

	list_for_each_entry_safe(pkt, n, &freeme, list) {
		if (pkt->reply)
			cnt++;
		list_del(&pkt->list);
		virtio_transport_free_pkt(pkt);
	}

	if (cnt) {
		struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
		int new_cnt;

		new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
		if (new_cnt + cnt >= virtqueue_get_vring_size(rx_vq) &&
		    new_cnt < virtqueue_get_vring_size(rx_vq))
			queue_work(virtio_vsock_workqueue, &vsock->rx_work);
	}

255 256 257 258 259
	ret = 0;

out_rcu:
	rcu_read_unlock();
	return ret;
P
Peng Tao 已提交
260 261
}

A
Asias He 已提交
262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282
static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
{
	int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
	struct virtio_vsock_pkt *pkt;
	struct scatterlist hdr, buf, *sgs[2];
	struct virtqueue *vq;
	int ret;

	vq = vsock->vqs[VSOCK_VQ_RX];

	do {
		pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
		if (!pkt)
			break;

		pkt->buf = kmalloc(buf_len, GFP_KERNEL);
		if (!pkt->buf) {
			virtio_transport_free_pkt(pkt);
			break;
		}

283
		pkt->buf_len = buf_len;
A
Asias He 已提交
284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311
		pkt->len = buf_len;

		sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
		sgs[0] = &hdr;

		sg_init_one(&buf, pkt->buf, buf_len);
		sgs[1] = &buf;
		ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL);
		if (ret) {
			virtio_transport_free_pkt(pkt);
			break;
		}
		vsock->rx_buf_nr++;
	} while (vq->num_free);
	if (vsock->rx_buf_nr > vsock->rx_buf_max_nr)
		vsock->rx_buf_max_nr = vsock->rx_buf_nr;
	virtqueue_kick(vq);
}

static void virtio_transport_tx_work(struct work_struct *work)
{
	struct virtio_vsock *vsock =
		container_of(work, struct virtio_vsock, tx_work);
	struct virtqueue *vq;
	bool added = false;

	vq = vsock->vqs[VSOCK_VQ_TX];
	mutex_lock(&vsock->tx_lock);
312 313 314 315

	if (!vsock->tx_run)
		goto out;

A
Asias He 已提交
316 317 318 319 320 321 322 323 324 325
	do {
		struct virtio_vsock_pkt *pkt;
		unsigned int len;

		virtqueue_disable_cb(vq);
		while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) {
			virtio_transport_free_pkt(pkt);
			added = true;
		}
	} while (!virtqueue_enable_cb(vq));
326 327

out:
A
Asias He 已提交
328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376
	mutex_unlock(&vsock->tx_lock);

	if (added)
		queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
}

/* Is there space left for replies to rx packets? */
static bool virtio_transport_more_replies(struct virtio_vsock *vsock)
{
	struct virtqueue *vq = vsock->vqs[VSOCK_VQ_RX];
	int val;

	smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
	val = atomic_read(&vsock->queued_replies);

	return val < virtqueue_get_vring_size(vq);
}

/* event_lock must be held */
static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock,
				       struct virtio_vsock_event *event)
{
	struct scatterlist sg;
	struct virtqueue *vq;

	vq = vsock->vqs[VSOCK_VQ_EVENT];

	sg_init_one(&sg, event, sizeof(*event));

	return virtqueue_add_inbuf(vq, &sg, 1, event, GFP_KERNEL);
}

/* event_lock must be held */
static void virtio_vsock_event_fill(struct virtio_vsock *vsock)
{
	size_t i;

	for (i = 0; i < ARRAY_SIZE(vsock->event_list); i++) {
		struct virtio_vsock_event *event = &vsock->event_list[i];

		virtio_vsock_event_fill_one(vsock, event);
	}

	virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
}

static void virtio_vsock_reset_sock(struct sock *sk)
{
	lock_sock(sk);
377
	sk->sk_state = TCP_CLOSE;
A
Asias He 已提交
378 379 380 381 382 383 384 385
	sk->sk_err = ECONNRESET;
	sk->sk_error_report(sk);
	release_sock(sk);
}

static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock)
{
	struct virtio_device *vdev = vsock->vdev;
386
	__le64 guest_cid;
A
Asias He 已提交
387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414

	vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid),
			  &guest_cid, sizeof(guest_cid));
	vsock->guest_cid = le64_to_cpu(guest_cid);
}

/* event_lock must be held */
static void virtio_vsock_event_handle(struct virtio_vsock *vsock,
				      struct virtio_vsock_event *event)
{
	switch (le32_to_cpu(event->id)) {
	case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET:
		virtio_vsock_update_guest_cid(vsock);
		vsock_for_each_connected_socket(virtio_vsock_reset_sock);
		break;
	}
}

static void virtio_transport_event_work(struct work_struct *work)
{
	struct virtio_vsock *vsock =
		container_of(work, struct virtio_vsock, event_work);
	struct virtqueue *vq;

	vq = vsock->vqs[VSOCK_VQ_EVENT];

	mutex_lock(&vsock->event_lock);

415 416 417
	if (!vsock->event_run)
		goto out;

A
Asias He 已提交
418 419 420 421 422 423 424 425 426 427 428 429 430 431
	do {
		struct virtio_vsock_event *event;
		unsigned int len;

		virtqueue_disable_cb(vq);
		while ((event = virtqueue_get_buf(vq, &len)) != NULL) {
			if (len == sizeof(*event))
				virtio_vsock_event_handle(vsock, event);

			virtio_vsock_event_fill_one(vsock, event);
		}
	} while (!virtqueue_enable_cb(vq));

	virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
432
out:
A
Asias He 已提交
433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471
	mutex_unlock(&vsock->event_lock);
}

static void virtio_vsock_event_done(struct virtqueue *vq)
{
	struct virtio_vsock *vsock = vq->vdev->priv;

	if (!vsock)
		return;
	queue_work(virtio_vsock_workqueue, &vsock->event_work);
}

static void virtio_vsock_tx_done(struct virtqueue *vq)
{
	struct virtio_vsock *vsock = vq->vdev->priv;

	if (!vsock)
		return;
	queue_work(virtio_vsock_workqueue, &vsock->tx_work);
}

static void virtio_vsock_rx_done(struct virtqueue *vq)
{
	struct virtio_vsock *vsock = vq->vdev->priv;

	if (!vsock)
		return;
	queue_work(virtio_vsock_workqueue, &vsock->rx_work);
}

static struct virtio_transport virtio_transport = {
	.transport = {
		.get_local_cid            = virtio_transport_get_local_cid,

		.init                     = virtio_transport_do_socket_init,
		.destruct                 = virtio_transport_destruct,
		.release                  = virtio_transport_release,
		.connect                  = virtio_transport_connect,
		.shutdown                 = virtio_transport_shutdown,
P
Peng Tao 已提交
472
		.cancel_pkt               = virtio_transport_cancel_pkt,
A
Asias He 已提交
473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496

		.dgram_bind               = virtio_transport_dgram_bind,
		.dgram_dequeue            = virtio_transport_dgram_dequeue,
		.dgram_enqueue            = virtio_transport_dgram_enqueue,
		.dgram_allow              = virtio_transport_dgram_allow,

		.stream_dequeue           = virtio_transport_stream_dequeue,
		.stream_enqueue           = virtio_transport_stream_enqueue,
		.stream_has_data          = virtio_transport_stream_has_data,
		.stream_has_space         = virtio_transport_stream_has_space,
		.stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
		.stream_is_active         = virtio_transport_stream_is_active,
		.stream_allow             = virtio_transport_stream_allow,

		.notify_poll_in           = virtio_transport_notify_poll_in,
		.notify_poll_out          = virtio_transport_notify_poll_out,
		.notify_recv_init         = virtio_transport_notify_recv_init,
		.notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
		.notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
		.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
		.notify_send_init         = virtio_transport_notify_send_init,
		.notify_send_pre_block    = virtio_transport_notify_send_pre_block,
		.notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
		.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
497
		.notify_buffer_size       = virtio_transport_notify_buffer_size,
A
Asias He 已提交
498 499 500 501 502
	},

	.send_pkt = virtio_transport_send_pkt,
};

503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582
static void virtio_transport_loopback_work(struct work_struct *work)
{
	struct virtio_vsock *vsock =
		container_of(work, struct virtio_vsock, loopback_work);
	LIST_HEAD(pkts);

	spin_lock_bh(&vsock->loopback_list_lock);
	list_splice_init(&vsock->loopback_list, &pkts);
	spin_unlock_bh(&vsock->loopback_list_lock);

	mutex_lock(&vsock->rx_lock);

	if (!vsock->rx_run)
		goto out;

	while (!list_empty(&pkts)) {
		struct virtio_vsock_pkt *pkt;

		pkt = list_first_entry(&pkts, struct virtio_vsock_pkt, list);
		list_del_init(&pkt->list);

		virtio_transport_recv_pkt(&virtio_transport, pkt);
	}
out:
	mutex_unlock(&vsock->rx_lock);
}

static void virtio_transport_rx_work(struct work_struct *work)
{
	struct virtio_vsock *vsock =
		container_of(work, struct virtio_vsock, rx_work);
	struct virtqueue *vq;

	vq = vsock->vqs[VSOCK_VQ_RX];

	mutex_lock(&vsock->rx_lock);

	if (!vsock->rx_run)
		goto out;

	do {
		virtqueue_disable_cb(vq);
		for (;;) {
			struct virtio_vsock_pkt *pkt;
			unsigned int len;

			if (!virtio_transport_more_replies(vsock)) {
				/* Stop rx until the device processes already
				 * pending replies.  Leave rx virtqueue
				 * callbacks disabled.
				 */
				goto out;
			}

			pkt = virtqueue_get_buf(vq, &len);
			if (!pkt) {
				break;
			}

			vsock->rx_buf_nr--;

			/* Drop short/long packets */
			if (unlikely(len < sizeof(pkt->hdr) ||
				     len > sizeof(pkt->hdr) + pkt->len)) {
				virtio_transport_free_pkt(pkt);
				continue;
			}

			pkt->len = len - sizeof(pkt->hdr);
			virtio_transport_deliver_tap_pkt(pkt);
			virtio_transport_recv_pkt(&virtio_transport, pkt);
		}
	} while (!virtqueue_enable_cb(vq));

out:
	if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2)
		virtio_vsock_rx_fill(vsock);
	mutex_unlock(&vsock->rx_lock);
}

A
Asias He 已提交
583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602
static int virtio_vsock_probe(struct virtio_device *vdev)
{
	vq_callback_t *callbacks[] = {
		virtio_vsock_rx_done,
		virtio_vsock_tx_done,
		virtio_vsock_event_done,
	};
	static const char * const names[] = {
		"rx",
		"tx",
		"event",
	};
	struct virtio_vsock *vsock = NULL;
	int ret;

	ret = mutex_lock_interruptible(&the_virtio_vsock_mutex);
	if (ret)
		return ret;

	/* Only one virtio-vsock device per guest is supported */
603 604
	if (rcu_dereference_protected(the_virtio_vsock,
				lockdep_is_held(&the_virtio_vsock_mutex))) {
A
Asias He 已提交
605 606 607 608 609 610 611 612 613 614 615 616
		ret = -EBUSY;
		goto out;
	}

	vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
	if (!vsock) {
		ret = -ENOMEM;
		goto out;
	}

	vsock->vdev = vdev;

M
Michael S. Tsirkin 已提交
617 618 619
	ret = virtio_find_vqs(vsock->vdev, VSOCK_VQ_MAX,
			      vsock->vqs, callbacks, names,
			      NULL);
A
Asias He 已提交
620 621 622 623 624 625 626 627 628 629 630 631 632 633
	if (ret < 0)
		goto out;

	virtio_vsock_update_guest_cid(vsock);

	vsock->rx_buf_nr = 0;
	vsock->rx_buf_max_nr = 0;
	atomic_set(&vsock->queued_replies, 0);

	mutex_init(&vsock->tx_lock);
	mutex_init(&vsock->rx_lock);
	mutex_init(&vsock->event_lock);
	spin_lock_init(&vsock->send_pkt_list_lock);
	INIT_LIST_HEAD(&vsock->send_pkt_list);
634 635
	spin_lock_init(&vsock->loopback_list_lock);
	INIT_LIST_HEAD(&vsock->loopback_list);
A
Asias He 已提交
636 637 638 639
	INIT_WORK(&vsock->rx_work, virtio_transport_rx_work);
	INIT_WORK(&vsock->tx_work, virtio_transport_tx_work);
	INIT_WORK(&vsock->event_work, virtio_transport_event_work);
	INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
640
	INIT_WORK(&vsock->loopback_work, virtio_transport_loopback_work);
A
Asias He 已提交
641

642 643 644 645
	mutex_lock(&vsock->tx_lock);
	vsock->tx_run = true;
	mutex_unlock(&vsock->tx_lock);

A
Asias He 已提交
646 647
	mutex_lock(&vsock->rx_lock);
	virtio_vsock_rx_fill(vsock);
648
	vsock->rx_run = true;
A
Asias He 已提交
649 650 651 652
	mutex_unlock(&vsock->rx_lock);

	mutex_lock(&vsock->event_lock);
	virtio_vsock_event_fill(vsock);
653
	vsock->event_run = true;
A
Asias He 已提交
654 655
	mutex_unlock(&vsock->event_lock);

656 657 658
	vdev->priv = vsock;
	rcu_assign_pointer(the_virtio_vsock, vsock);

A
Asias He 已提交
659 660 661 662 663 664 665 666 667 668 669 670 671 672
	mutex_unlock(&the_virtio_vsock_mutex);
	return 0;

out:
	kfree(vsock);
	mutex_unlock(&the_virtio_vsock_mutex);
	return ret;
}

static void virtio_vsock_remove(struct virtio_device *vdev)
{
	struct virtio_vsock *vsock = vdev->priv;
	struct virtio_vsock_pkt *pkt;

673 674 675 676 677 678
	mutex_lock(&the_virtio_vsock_mutex);

	vdev->priv = NULL;
	rcu_assign_pointer(the_virtio_vsock, NULL);
	synchronize_rcu();

679 680 681
	/* Reset all connected sockets when the device disappear */
	vsock_for_each_connected_socket(virtio_vsock_reset_sock);

682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699
	/* Stop all work handlers to make sure no one is accessing the device,
	 * so we can safely call vdev->config->reset().
	 */
	mutex_lock(&vsock->rx_lock);
	vsock->rx_run = false;
	mutex_unlock(&vsock->rx_lock);

	mutex_lock(&vsock->tx_lock);
	vsock->tx_run = false;
	mutex_unlock(&vsock->tx_lock);

	mutex_lock(&vsock->event_lock);
	vsock->event_run = false;
	mutex_unlock(&vsock->event_lock);

	/* Flush all device writes and interrupts, device will not use any
	 * more buffers.
	 */
A
Asias He 已提交
700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720
	vdev->config->reset(vdev);

	mutex_lock(&vsock->rx_lock);
	while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX])))
		virtio_transport_free_pkt(pkt);
	mutex_unlock(&vsock->rx_lock);

	mutex_lock(&vsock->tx_lock);
	while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX])))
		virtio_transport_free_pkt(pkt);
	mutex_unlock(&vsock->tx_lock);

	spin_lock_bh(&vsock->send_pkt_list_lock);
	while (!list_empty(&vsock->send_pkt_list)) {
		pkt = list_first_entry(&vsock->send_pkt_list,
				       struct virtio_vsock_pkt, list);
		list_del(&pkt->list);
		virtio_transport_free_pkt(pkt);
	}
	spin_unlock_bh(&vsock->send_pkt_list_lock);

721 722 723 724 725 726 727 728 729
	spin_lock_bh(&vsock->loopback_list_lock);
	while (!list_empty(&vsock->loopback_list)) {
		pkt = list_first_entry(&vsock->loopback_list,
				       struct virtio_vsock_pkt, list);
		list_del(&pkt->list);
		virtio_transport_free_pkt(pkt);
	}
	spin_unlock_bh(&vsock->loopback_list_lock);

730
	/* Delete virtqueues and flush outstanding callbacks if any */
A
Asias He 已提交
731 732
	vdev->config->del_vqs(vdev);

733 734 735 736 737 738 739 740 741
	/* Other works can be queued before 'config->del_vqs()', so we flush
	 * all works before to free the vsock object to avoid use after free.
	 */
	flush_work(&vsock->loopback_work);
	flush_work(&vsock->rx_work);
	flush_work(&vsock->tx_work);
	flush_work(&vsock->event_work);
	flush_work(&vsock->send_pkt_work);

742 743
	mutex_unlock(&the_virtio_vsock_mutex);

A
Asias He 已提交
744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771
	kfree(vsock);
}

static struct virtio_device_id id_table[] = {
	{ VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID },
	{ 0 },
};

static unsigned int features[] = {
};

static struct virtio_driver virtio_vsock_driver = {
	.feature_table = features,
	.feature_table_size = ARRAY_SIZE(features),
	.driver.name = KBUILD_MODNAME,
	.driver.owner = THIS_MODULE,
	.id_table = id_table,
	.probe = virtio_vsock_probe,
	.remove = virtio_vsock_remove,
};

static int __init virtio_vsock_init(void)
{
	int ret;

	virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0);
	if (!virtio_vsock_workqueue)
		return -ENOMEM;
772

773
	ret = vsock_core_init(&virtio_transport.transport);
A
Asias He 已提交
774
	if (ret)
775 776
		goto out_wq;

777
	ret = register_virtio_driver(&virtio_vsock_driver);
778
	if (ret)
779
		goto out_vci;
780 781 782

	return 0;

783 784
out_vci:
	vsock_core_exit();
785 786
out_wq:
	destroy_workqueue(virtio_vsock_workqueue);
A
Asias He 已提交
787 788 789 790 791 792
	return ret;
}

static void __exit virtio_vsock_exit(void)
{
	unregister_virtio_driver(&virtio_vsock_driver);
793
	vsock_core_exit();
A
Asias He 已提交
794 795 796 797 798 799 800 801 802
	destroy_workqueue(virtio_vsock_workqueue);
}

module_init(virtio_vsock_init);
module_exit(virtio_vsock_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Asias He");
MODULE_DESCRIPTION("virtio transport for vsock");
MODULE_DEVICE_TABLE(virtio, id_table);