[mirror_ubuntu-bionic-kernel.git] / net / vmw_vsock / virtio_transport.c

/*
 * 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.
 *
 * This work is licensed under the terms of the GNU GPL, version 2.
 */
#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;

	struct work_struct send_pkt_work;
	spinlock_t send_pkt_list_lock;
	struct list_head send_pkt_list;

	struct work_struct loopback_work;
	spinlock_t loopback_list_lock; /* protects loopback_list */
	struct list_head loopback_list;

	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;
	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;
	struct virtio_vsock_event event_list[8];

	u32 guest_cid;
};

static struct virtio_vsock *virtio_vsock_get(void)
{
	return the_virtio_vsock;
}

static u32 virtio_transport_get_local_cid(void)
{
	struct virtio_vsock *vsock = virtio_vsock_get();

	if (!vsock)
		return VMADDR_CID_ANY;

	return vsock->guest_cid;
}

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);
	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(pkt);
	}
	mutex_unlock(&vsock->rx_lock);
}

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;
}

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);

	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);

		virtio_transport_deliver_tap_pkt(pkt);

		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);
		/* Usually this means that there is no more space available in
		 * the vq
		 */
		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);

	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;

	vsock = virtio_vsock_get();
	if (!vsock) {
		virtio_transport_free_pkt(pkt);
		return -ENODEV;
	}

	if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid)
		return virtio_transport_send_pkt_loopback(vsock, pkt);

	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);
	return len;
}

static int
virtio_transport_cancel_pkt(struct vsock_sock *vsk)
{
	struct virtio_vsock *vsock;
	struct virtio_vsock_pkt *pkt, *n;
	int cnt = 0;
	LIST_HEAD(freeme);

	vsock = virtio_vsock_get();
	if (!vsock) {
		return -ENODEV;
	}

	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);
	}

	return 0;
}

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;
		}

		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);
	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));
	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);
}

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);

	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(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);
}

/* 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);
	sk->sk_state = TCP_CLOSE;
	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;
	__le64 guest_cid;

	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);

	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]);

	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,
		.cancel_pkt               = virtio_transport_cancel_pkt,

		.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,

		.set_buffer_size          = virtio_transport_set_buffer_size,
		.set_min_buffer_size      = virtio_transport_set_min_buffer_size,
		.set_max_buffer_size      = virtio_transport_set_max_buffer_size,
		.get_buffer_size          = virtio_transport_get_buffer_size,
		.get_min_buffer_size      = virtio_transport_get_min_buffer_size,
		.get_max_buffer_size      = virtio_transport_get_max_buffer_size,
	},

	.send_pkt = virtio_transport_send_pkt,
};

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 */
	if (the_virtio_vsock) {
		ret = -EBUSY;
		goto out;
	}

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

	vsock->vdev = vdev;

	ret = virtio_find_vqs(vsock->vdev, VSOCK_VQ_MAX,
			      vsock->vqs, callbacks, names,
			      NULL);
	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);

	vdev->priv = vsock;
	the_virtio_vsock = vsock;
	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);
	spin_lock_init(&vsock->loopback_list_lock);
	INIT_LIST_HEAD(&vsock->loopback_list);
	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);
	INIT_WORK(&vsock->loopback_work, virtio_transport_loopback_work);

	mutex_lock(&vsock->rx_lock);
	virtio_vsock_rx_fill(vsock);
	mutex_unlock(&vsock->rx_lock);

	mutex_lock(&vsock->event_lock);
	virtio_vsock_event_fill(vsock);
	mutex_unlock(&vsock->event_lock);

	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;

	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);

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

	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);

	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);

	mutex_lock(&the_virtio_vsock_mutex);
	the_virtio_vsock = NULL;
	mutex_unlock(&the_virtio_vsock_mutex);

	vdev->config->del_vqs(vdev);

	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;

	ret = vsock_core_init(&virtio_transport.transport);
	if (ret)
		goto out_wq;

	ret = register_virtio_driver(&virtio_vsock_driver);
	if (ret)
		goto out_vci;

	return 0;

out_vci:
	vsock_core_exit();
out_wq:
	destroy_workqueue(virtio_vsock_workqueue);
	return ret;
}

static void __exit virtio_vsock_exit(void)
{
	unregister_virtio_driver(&virtio_vsock_driver);
	vsock_core_exit();
	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);
Commit	Line	Data
0ea9e1d3 AH	1	/*
	2	* virtio transport for vsock
	3	*
	4	* Copyright (C) 2013-2015 Red Hat, Inc.
	5	* Author: Asias He <asias@redhat.com>
	6	* Stefan Hajnoczi <stefanha@redhat.com>
	7	*
	8	* Some of the code is take from Gerd Hoffmann <kraxel@redhat.com>'s
	9	* early virtio-vsock proof-of-concept bits.
	10	*
	11	* This work is licensed under the terms of the GNU GPL, version 2.
	12	*/
	13	#include <linux/spinlock.h>
	14	#include <linux/module.h>
	15	#include <linux/list.h>
	16	#include <linux/atomic.h>
	17	#include <linux/virtio.h>
	18	#include <linux/virtio_ids.h>
	19	#include <linux/virtio_config.h>
	20	#include <linux/virtio_vsock.h>
	21	#include <net/sock.h>
	22	#include <linux/mutex.h>
	23	#include <net/af_vsock.h>
	24
	25	static struct workqueue_struct *virtio_vsock_workqueue;
	26	static struct virtio_vsock *the_virtio_vsock;
	27	static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */
	28
	29	struct virtio_vsock {
	30	struct virtio_device *vdev;
	31	struct virtqueue *vqs[VSOCK_VQ_MAX];
	32
	33	/* Virtqueue processing is deferred to a workqueue */
	34	struct work_struct tx_work;
	35	struct work_struct rx_work;
	36	struct work_struct event_work;
	37
	38	/* The following fields are protected by tx_lock. vqs[VSOCK_VQ_TX]
	39	* must be accessed with tx_lock held.
	40	*/
	41	struct mutex tx_lock;
	42
	43	struct work_struct send_pkt_work;
	44	spinlock_t send_pkt_list_lock;
	45	struct list_head send_pkt_list;
	46
b9116823 SH	47	struct work_struct loopback_work;
	48	spinlock_t loopback_list_lock; /* protects loopback_list */
	49	struct list_head loopback_list;
	50
0ea9e1d3 AH	51	atomic_t queued_replies;
	52
	53	/* The following fields are protected by rx_lock. vqs[VSOCK_VQ_RX]
	54	* must be accessed with rx_lock held.
	55	*/
	56	struct mutex rx_lock;
	57	int rx_buf_nr;
	58	int rx_buf_max_nr;
	59
	60	/* The following fields are protected by event_lock.
	61	* vqs[VSOCK_VQ_EVENT] must be accessed with event_lock held.
	62	*/
	63	struct mutex event_lock;
	64	struct virtio_vsock_event event_list[8];
	65
	66	u32 guest_cid;
	67	};
	68
	69	static struct virtio_vsock *virtio_vsock_get(void)
	70	{
	71	return the_virtio_vsock;
	72	}
	73
	74	static u32 virtio_transport_get_local_cid(void)
	75	{
	76	struct virtio_vsock *vsock = virtio_vsock_get();
	77
0fe6e3cf SG	78	if (!vsock)
	79	return VMADDR_CID_ANY;
	80
0ea9e1d3 AH	81	return vsock->guest_cid;
	82	}
	83
b9116823 SH	84	static void virtio_transport_loopback_work(struct work_struct *work)
	85	{
	86	struct virtio_vsock *vsock =
	87	container_of(work, struct virtio_vsock, loopback_work);
	88	LIST_HEAD(pkts);
	89
	90	spin_lock_bh(&vsock->loopback_list_lock);
	91	list_splice_init(&vsock->loopback_list, &pkts);
	92	spin_unlock_bh(&vsock->loopback_list_lock);
	93
	94	mutex_lock(&vsock->rx_lock);
	95	while (!list_empty(&pkts)) {
	96	struct virtio_vsock_pkt *pkt;
	97
	98	pkt = list_first_entry(&pkts, struct virtio_vsock_pkt, list);
	99	list_del_init(&pkt->list);
	100
	101	virtio_transport_recv_pkt(pkt);
	102	}
	103	mutex_unlock(&vsock->rx_lock);
	104	}
	105
	106	static int virtio_transport_send_pkt_loopback(struct virtio_vsock *vsock,
	107	struct virtio_vsock_pkt *pkt)
	108	{
	109	int len = pkt->len;
	110
	111	spin_lock_bh(&vsock->loopback_list_lock);
	112	list_add_tail(&pkt->list, &vsock->loopback_list);
	113	spin_unlock_bh(&vsock->loopback_list_lock);
	114
	115	queue_work(virtio_vsock_workqueue, &vsock->loopback_work);
	116
	117	return len;
	118	}
	119
0ea9e1d3 AH	120	static void
	121	virtio_transport_send_pkt_work(struct work_struct *work)
	122	{
	123	struct virtio_vsock *vsock =
	124	container_of(work, struct virtio_vsock, send_pkt_work);
	125	struct virtqueue *vq;
	126	bool added = false;
	127	bool restart_rx = false;
	128
	129	mutex_lock(&vsock->tx_lock);
	130
	131	vq = vsock->vqs[VSOCK_VQ_TX];
	132
0ea9e1d3 AH	133	for (;;) {
	134	struct virtio_vsock_pkt *pkt;
	135	struct scatterlist hdr, buf, *sgs[2];
	136	int ret, in_sg = 0, out_sg = 0;
	137	bool reply;
	138
	139	spin_lock_bh(&vsock->send_pkt_list_lock);
	140	if (list_empty(&vsock->send_pkt_list)) {
	141	spin_unlock_bh(&vsock->send_pkt_list_lock);
0ea9e1d3 AH	142	break;
	143	}
	144
	145	pkt = list_first_entry(&vsock->send_pkt_list,
	146	struct virtio_vsock_pkt, list);
	147	list_del_init(&pkt->list);
	148	spin_unlock_bh(&vsock->send_pkt_list_lock);
	149
82dfb540 GG	150	virtio_transport_deliver_tap_pkt(pkt);
82dfb540 GG	151
0ea9e1d3 AH	152	reply = pkt->reply;
	153
	154	sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
	155	sgs[out_sg++] = &hdr;
	156	if (pkt->buf) {
	157	sg_init_one(&buf, pkt->buf, pkt->len);
	158	sgs[out_sg++] = &buf;
	159	}
	160
	161	ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt, GFP_KERNEL);
21bc54fc GG	162	/* Usually this means that there is no more space available in
	163	* the vq
	164	*/
0ea9e1d3 AH	165	if (ret < 0) {
	166	spin_lock_bh(&vsock->send_pkt_list_lock);
	167	list_add(&pkt->list, &vsock->send_pkt_list);
	168	spin_unlock_bh(&vsock->send_pkt_list_lock);
0ea9e1d3 AH	169	break;
	170	}
	171
	172	if (reply) {
	173	struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
	174	int val;
	175
	176	val = atomic_dec_return(&vsock->queued_replies);
	177
	178	/* Do we now have resources to resume rx processing? */
	179	if (val + 1 == virtqueue_get_vring_size(rx_vq))
	180	restart_rx = true;
	181	}
	182
	183	added = true;
	184	}
	185
	186	if (added)
	187	virtqueue_kick(vq);
	188
	189	mutex_unlock(&vsock->tx_lock);
	190
	191	if (restart_rx)
	192	queue_work(virtio_vsock_workqueue, &vsock->rx_work);
	193	}
	194
	195	static int
	196	virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt)
	197	{
	198	struct virtio_vsock *vsock;
	199	int len = pkt->len;
	200
	201	vsock = virtio_vsock_get();
	202	if (!vsock) {
	203	virtio_transport_free_pkt(pkt);
	204	return -ENODEV;
	205	}
	206
434fad98	207	if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid)
b9116823 SH	208	return virtio_transport_send_pkt_loopback(vsock, pkt);
b9116823 SH	209
0ea9e1d3 AH	210	if (pkt->reply)
	211	atomic_inc(&vsock->queued_replies);
	212
	213	spin_lock_bh(&vsock->send_pkt_list_lock);
	214	list_add_tail(&pkt->list, &vsock->send_pkt_list);
	215	spin_unlock_bh(&vsock->send_pkt_list_lock);
	216
	217	queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
	218	return len;
	219	}
	220
073b4f2c PT	221	static int
	222	virtio_transport_cancel_pkt(struct vsock_sock *vsk)
	223	{
	224	struct virtio_vsock *vsock;
	225	struct virtio_vsock_pkt pkt, n;
	226	int cnt = 0;
	227	LIST_HEAD(freeme);
	228
	229	vsock = virtio_vsock_get();
	230	if (!vsock) {
	231	return -ENODEV;
	232	}
	233
	234	spin_lock_bh(&vsock->send_pkt_list_lock);
	235	list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) {
	236	if (pkt->vsk != vsk)
	237	continue;
	238	list_move(&pkt->list, &freeme);
	239	}
	240	spin_unlock_bh(&vsock->send_pkt_list_lock);
	241
	242	list_for_each_entry_safe(pkt, n, &freeme, list) {
	243	if (pkt->reply)
	244	cnt++;
	245	list_del(&pkt->list);
	246	virtio_transport_free_pkt(pkt);
	247	}
	248
	249	if (cnt) {
	250	struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX];
	251	int new_cnt;
	252
	253	new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
	254	if (new_cnt + cnt >= virtqueue_get_vring_size(rx_vq) &&
	255	new_cnt < virtqueue_get_vring_size(rx_vq))
	256	queue_work(virtio_vsock_workqueue, &vsock->rx_work);
	257	}
	258
	259	return 0;
	260	}
	261
0ea9e1d3 AH	262	static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
	263	{
	264	int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
	265	struct virtio_vsock_pkt *pkt;
	266	struct scatterlist hdr, buf, *sgs[2];
	267	struct virtqueue *vq;
	268	int ret;
	269
	270	vq = vsock->vqs[VSOCK_VQ_RX];
	271
	272	do {
	273	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
	274	if (!pkt)
	275	break;
	276
	277	pkt->buf = kmalloc(buf_len, GFP_KERNEL);
	278	if (!pkt->buf) {
	279	virtio_transport_free_pkt(pkt);
	280	break;
	281	}
	282
	283	pkt->len = buf_len;
	284
	285	sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
	286	sgs[0] = &hdr;
	287
	288	sg_init_one(&buf, pkt->buf, buf_len);
	289	sgs[1] = &buf;
	290	ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL);
	291	if (ret) {
	292	virtio_transport_free_pkt(pkt);
	293	break;
	294	}
	295	vsock->rx_buf_nr++;
	296	} while (vq->num_free);
	297	if (vsock->rx_buf_nr > vsock->rx_buf_max_nr)
	298	vsock->rx_buf_max_nr = vsock->rx_buf_nr;
	299	virtqueue_kick(vq);
	300	}
	301
	302	static void virtio_transport_tx_work(struct work_struct *work)
	303	{
	304	struct virtio_vsock *vsock =
	305	container_of(work, struct virtio_vsock, tx_work);
	306	struct virtqueue *vq;
	307	bool added = false;
	308
	309	vq = vsock->vqs[VSOCK_VQ_TX];
	310	mutex_lock(&vsock->tx_lock);
	311	do {
	312	struct virtio_vsock_pkt *pkt;
	313	unsigned int len;
	314
	315	virtqueue_disable_cb(vq);
	316	while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) {
	317	virtio_transport_free_pkt(pkt);
	318	added = true;
	319	}
	320	} while (!virtqueue_enable_cb(vq));
	321	mutex_unlock(&vsock->tx_lock);
	322
	323	if (added)
	324	queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
	325	}
326
327	/* Is there space left for replies to rx packets? */
328	static bool virtio_transport_more_replies(struct virtio_vsock *vsock)
329	{
330	struct virtqueue *vq = vsock->vqs[VSOCK_VQ_RX];
331	int val;
332
333	smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
334	val = atomic_read(&vsock->queued_replies);
335
336	return val < virtqueue_get_vring_size(vq);
337	}
338
339	static void virtio_transport_rx_work(struct work_struct *work)
340	{
341	struct virtio_vsock *vsock =
342	container_of(work, struct virtio_vsock, rx_work);
343	struct virtqueue *vq;
344
345	vq = vsock->vqs[VSOCK_VQ_RX];
346
347	mutex_lock(&vsock->rx_lock);
348
349	do {
350	virtqueue_disable_cb(vq);
351	for (;;) {
352	struct virtio_vsock_pkt *pkt;
353	unsigned int len;
354
355	if (!virtio_transport_more_replies(vsock)) {
356	/* Stop rx until the device processes already
357	* pending replies. Leave rx virtqueue
358	* callbacks disabled.
359	*/
360	goto out;
361	}
362
363	pkt = virtqueue_get_buf(vq, &len);
364	if (!pkt) {
365	break;
366	}
367
368	vsock->rx_buf_nr--;
369
370	/* Drop short/long packets */
371	if (unlikely(len < sizeof(pkt->hdr) \|\|
372	len > sizeof(pkt->hdr) + pkt->len)) {
373	virtio_transport_free_pkt(pkt);
374	continue;
375	}
376
377	pkt->len = len - sizeof(pkt->hdr);
82dfb540	378	virtio_transport_deliver_tap_pkt(pkt);
0ea9e1d3 AH	379	virtio_transport_recv_pkt(pkt);
	380	}
	381	} while (!virtqueue_enable_cb(vq));
	382
	383	out:
	384	if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2)
	385	virtio_vsock_rx_fill(vsock);
	386	mutex_unlock(&vsock->rx_lock);
	387	}
	388
	389	/* event_lock must be held */
	390	static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock,
	391	struct virtio_vsock_event *event)
	392	{
	393	struct scatterlist sg;
	394	struct virtqueue *vq;
	395
	396	vq = vsock->vqs[VSOCK_VQ_EVENT];
	397
	398	sg_init_one(&sg, event, sizeof(*event));
	399
	400	return virtqueue_add_inbuf(vq, &sg, 1, event, GFP_KERNEL);
	401	}
	402
	403	/* event_lock must be held */
	404	static void virtio_vsock_event_fill(struct virtio_vsock *vsock)
	405	{
	406	size_t i;
	407
	408	for (i = 0; i < ARRAY_SIZE(vsock->event_list); i++) {
	409	struct virtio_vsock_event *event = &vsock->event_list[i];
	410
	411	virtio_vsock_event_fill_one(vsock, event);
	412	}
	413
	414	virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
	415	}
	416
	417	static void virtio_vsock_reset_sock(struct sock *sk)
	418	{
	419	lock_sock(sk);
3b4477d2	420	sk->sk_state = TCP_CLOSE;
0ea9e1d3 AH	421	sk->sk_err = ECONNRESET;
	422	sk->sk_error_report(sk);
	423	release_sock(sk);
	424	}
	425
	426	static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock)
	427	{
	428	struct virtio_device *vdev = vsock->vdev;
6c7efafd	429	__le64 guest_cid;
0ea9e1d3 AH	430
	431	vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid),
	432	&guest_cid, sizeof(guest_cid));
	433	vsock->guest_cid = le64_to_cpu(guest_cid);
	434	}
	435
	436	/* event_lock must be held */
	437	static void virtio_vsock_event_handle(struct virtio_vsock *vsock,
	438	struct virtio_vsock_event *event)
	439	{
	440	switch (le32_to_cpu(event->id)) {
	441	case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET:
	442	virtio_vsock_update_guest_cid(vsock);
	443	vsock_for_each_connected_socket(virtio_vsock_reset_sock);
	444	break;
	445	}
	446	}
	447
	448	static void virtio_transport_event_work(struct work_struct *work)
	449	{
	450	struct virtio_vsock *vsock =
	451	container_of(work, struct virtio_vsock, event_work);
	452	struct virtqueue *vq;
	453
	454	vq = vsock->vqs[VSOCK_VQ_EVENT];
	455
	456	mutex_lock(&vsock->event_lock);
	457
	458	do {
	459	struct virtio_vsock_event *event;
	460	unsigned int len;
	461
	462	virtqueue_disable_cb(vq);
	463	while ((event = virtqueue_get_buf(vq, &len)) != NULL) {
	464	if (len == sizeof(*event))
	465	virtio_vsock_event_handle(vsock, event);
	466
	467	virtio_vsock_event_fill_one(vsock, event);
	468	}
	469	} while (!virtqueue_enable_cb(vq));
	470
	471	virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]);
	472
	473	mutex_unlock(&vsock->event_lock);
	474	}
	475
	476	static void virtio_vsock_event_done(struct virtqueue *vq)
	477	{
	478	struct virtio_vsock *vsock = vq->vdev->priv;
	479
	480	if (!vsock)
	481	return;
	482	queue_work(virtio_vsock_workqueue, &vsock->event_work);
	483	}
	484
	485	static void virtio_vsock_tx_done(struct virtqueue *vq)
	486	{
	487	struct virtio_vsock *vsock = vq->vdev->priv;
	488
	489	if (!vsock)
	490	return;
	491	queue_work(virtio_vsock_workqueue, &vsock->tx_work);
	492	}
	493
494	static void virtio_vsock_rx_done(struct virtqueue *vq)
495	{
496	struct virtio_vsock *vsock = vq->vdev->priv;
497
498	if (!vsock)
499	return;
500	queue_work(virtio_vsock_workqueue, &vsock->rx_work);
501	}
502
503	static struct virtio_transport virtio_transport = {
504	.transport = {
505	.get_local_cid = virtio_transport_get_local_cid,
506
507	.init = virtio_transport_do_socket_init,
508	.destruct = virtio_transport_destruct,
509	.release = virtio_transport_release,
510	.connect = virtio_transport_connect,
511	.shutdown = virtio_transport_shutdown,
073b4f2c	512	.cancel_pkt = virtio_transport_cancel_pkt,
0ea9e1d3 AH	513
	514	.dgram_bind = virtio_transport_dgram_bind,
	515	.dgram_dequeue = virtio_transport_dgram_dequeue,
	516	.dgram_enqueue = virtio_transport_dgram_enqueue,
	517	.dgram_allow = virtio_transport_dgram_allow,
	518
	519	.stream_dequeue = virtio_transport_stream_dequeue,
	520	.stream_enqueue = virtio_transport_stream_enqueue,
	521	.stream_has_data = virtio_transport_stream_has_data,
	522	.stream_has_space = virtio_transport_stream_has_space,
	523	.stream_rcvhiwat = virtio_transport_stream_rcvhiwat,
	524	.stream_is_active = virtio_transport_stream_is_active,
	525	.stream_allow = virtio_transport_stream_allow,
	526
	527	.notify_poll_in = virtio_transport_notify_poll_in,
	528	.notify_poll_out = virtio_transport_notify_poll_out,
	529	.notify_recv_init = virtio_transport_notify_recv_init,
	530	.notify_recv_pre_block = virtio_transport_notify_recv_pre_block,
	531	.notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue,
	532	.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
	533	.notify_send_init = virtio_transport_notify_send_init,
	534	.notify_send_pre_block = virtio_transport_notify_send_pre_block,
	535	.notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue,
	536	.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
	537
	538	.set_buffer_size = virtio_transport_set_buffer_size,
	539	.set_min_buffer_size = virtio_transport_set_min_buffer_size,
	540	.set_max_buffer_size = virtio_transport_set_max_buffer_size,
	541	.get_buffer_size = virtio_transport_get_buffer_size,
	542	.get_min_buffer_size = virtio_transport_get_min_buffer_size,
	543	.get_max_buffer_size = virtio_transport_get_max_buffer_size,
	544	},
	545
	546	.send_pkt = virtio_transport_send_pkt,
	547	};
	548
	549	static int virtio_vsock_probe(struct virtio_device *vdev)
	550	{
	551	vq_callback_t *callbacks[] = {
	552	virtio_vsock_rx_done,
	553	virtio_vsock_tx_done,
	554	virtio_vsock_event_done,
	555	};
	556	static const char * const names[] = {
	557	"rx",
	558	"tx",
	559	"event",
	560	};
	561	struct virtio_vsock *vsock = NULL;
	562	int ret;
	563
	564	ret = mutex_lock_interruptible(&the_virtio_vsock_mutex);
	565	if (ret)
	566	return ret;
	567
	568	/* Only one virtio-vsock device per guest is supported */
	569	if (the_virtio_vsock) {
	570	ret = -EBUSY;
	571	goto out;
	572	}
	573
	574	vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
	575	if (!vsock) {
	576	ret = -ENOMEM;
577	goto out;
578	}
579
580	vsock->vdev = vdev;
581
9b2bbdb2 MT	582	ret = virtio_find_vqs(vsock->vdev, VSOCK_VQ_MAX,
	583	vsock->vqs, callbacks, names,
	584	NULL);
0ea9e1d3 AH	585	if (ret < 0)
	586	goto out;
	587
	588	virtio_vsock_update_guest_cid(vsock);
	589
0ea9e1d3 AH	590	vsock->rx_buf_nr = 0;
	591	vsock->rx_buf_max_nr = 0;
	592	atomic_set(&vsock->queued_replies, 0);
	593
	594	vdev->priv = vsock;
	595	the_virtio_vsock = vsock;
	596	mutex_init(&vsock->tx_lock);
	597	mutex_init(&vsock->rx_lock);
	598	mutex_init(&vsock->event_lock);
	599	spin_lock_init(&vsock->send_pkt_list_lock);
	600	INIT_LIST_HEAD(&vsock->send_pkt_list);
b9116823 SH	601	spin_lock_init(&vsock->loopback_list_lock);
b9116823 SH	602	INIT_LIST_HEAD(&vsock->loopback_list);
0ea9e1d3 AH	603	INIT_WORK(&vsock->rx_work, virtio_transport_rx_work);
	604	INIT_WORK(&vsock->tx_work, virtio_transport_tx_work);
	605	INIT_WORK(&vsock->event_work, virtio_transport_event_work);
	606	INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
b9116823	607	INIT_WORK(&vsock->loopback_work, virtio_transport_loopback_work);
0ea9e1d3 AH	608
	609	mutex_lock(&vsock->rx_lock);
	610	virtio_vsock_rx_fill(vsock);
	611	mutex_unlock(&vsock->rx_lock);
	612
	613	mutex_lock(&vsock->event_lock);
	614	virtio_vsock_event_fill(vsock);
	615	mutex_unlock(&vsock->event_lock);
	616
	617	mutex_unlock(&the_virtio_vsock_mutex);
	618	return 0;
	619
0ea9e1d3 AH	620	out:
	621	kfree(vsock);
	622	mutex_unlock(&the_virtio_vsock_mutex);
	623	return ret;
	624	}
	625
	626	static void virtio_vsock_remove(struct virtio_device *vdev)
	627	{
	628	struct virtio_vsock *vsock = vdev->priv;
	629	struct virtio_vsock_pkt *pkt;
	630
b9116823	631	flush_work(&vsock->loopback_work);
0ea9e1d3 AH	632	flush_work(&vsock->rx_work);
	633	flush_work(&vsock->tx_work);
	634	flush_work(&vsock->event_work);
	635	flush_work(&vsock->send_pkt_work);
	636
9f993ba8 SG	637	/* Reset all connected sockets when the device disappear */
	638	vsock_for_each_connected_socket(virtio_vsock_reset_sock);
	639
0ea9e1d3 AH	640	vdev->config->reset(vdev);
	641
	642	mutex_lock(&vsock->rx_lock);
	643	while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_RX])))
	644	virtio_transport_free_pkt(pkt);
	645	mutex_unlock(&vsock->rx_lock);
	646
	647	mutex_lock(&vsock->tx_lock);
	648	while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX])))
	649	virtio_transport_free_pkt(pkt);
	650	mutex_unlock(&vsock->tx_lock);
	651
	652	spin_lock_bh(&vsock->send_pkt_list_lock);
	653	while (!list_empty(&vsock->send_pkt_list)) {
	654	pkt = list_first_entry(&vsock->send_pkt_list,
	655	struct virtio_vsock_pkt, list);
	656	list_del(&pkt->list);
	657	virtio_transport_free_pkt(pkt);
	658	}
	659	spin_unlock_bh(&vsock->send_pkt_list_lock);
	660
b9116823 SH	661	spin_lock_bh(&vsock->loopback_list_lock);
	662	while (!list_empty(&vsock->loopback_list)) {
	663	pkt = list_first_entry(&vsock->loopback_list,
	664	struct virtio_vsock_pkt, list);
	665	list_del(&pkt->list);
	666	virtio_transport_free_pkt(pkt);
	667	}
	668	spin_unlock_bh(&vsock->loopback_list_lock);
	669
0ea9e1d3 AH	670	mutex_lock(&the_virtio_vsock_mutex);
0ea9e1d3 AH	671	the_virtio_vsock = NULL;
0ea9e1d3 AH	672	mutex_unlock(&the_virtio_vsock_mutex);
	673
	674	vdev->config->del_vqs(vdev);
	675
	676	kfree(vsock);
	677	}
	678
	679	static struct virtio_device_id id_table[] = {
	680	{ VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID },
	681	{ 0 },
	682	};
	683
	684	static unsigned int features[] = {
	685	};
	686
	687	static struct virtio_driver virtio_vsock_driver = {
	688	.feature_table = features,
	689	.feature_table_size = ARRAY_SIZE(features),
	690	.driver.name = KBUILD_MODNAME,
	691	.driver.owner = THIS_MODULE,
	692	.id_table = id_table,
	693	.probe = virtio_vsock_probe,
	694	.remove = virtio_vsock_remove,
	695	};
	696
	697	static int __init virtio_vsock_init(void)
	698	{
	699	int ret;
	700
	701	virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0);
	702	if (!virtio_vsock_workqueue)
	703	return -ENOMEM;
0fe6e3cf	704
f0240a6d	705	ret = vsock_core_init(&virtio_transport.transport);
0ea9e1d3	706	if (ret)
0fe6e3cf SG	707	goto out_wq;
0fe6e3cf SG	708
f0240a6d	709	ret = register_virtio_driver(&virtio_vsock_driver);
0fe6e3cf	710	if (ret)
f0240a6d	711	goto out_vci;
0fe6e3cf SG	712
	713	return 0;
	714
f0240a6d JM	715	out_vci:
f0240a6d JM	716	vsock_core_exit();
0fe6e3cf SG	717	out_wq:
0fe6e3cf SG	718	destroy_workqueue(virtio_vsock_workqueue);
0ea9e1d3 AH	719	return ret;
	720	}
	721
	722	static void __exit virtio_vsock_exit(void)
	723	{
	724	unregister_virtio_driver(&virtio_vsock_driver);
f0240a6d	725	vsock_core_exit();
0ea9e1d3 AH	726	destroy_workqueue(virtio_vsock_workqueue);
	727	}
	728
	729	module_init(virtio_vsock_init);
	730	module_exit(virtio_vsock_exit);
	731	MODULE_LICENSE("GPL v2");
	732	MODULE_AUTHOR("Asias He");
	733	MODULE_DESCRIPTION("virtio transport for vsock");
	734	MODULE_DEVICE_TABLE(virtio, id_table);