// SPDX-License-Identifier: GPL-2.0-only
/*
* vhost transport for vsock
*
* Copyright (C) 2013-2015 Red Hat, Inc.
* Author: Asias He <[email protected]>
* Stefan Hajnoczi <[email protected]>
*/
#include <linux/miscdevice.h>
#include <linux/atomic.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/vmalloc.h>
#include <net/sock.h>
#include <linux/virtio_vsock.h>
#include <linux/vhost.h>
#include <linux/hashtable.h>
#include <net/af_vsock.h>
#include "vhost.h"
#define VHOST_VSOCK_DEFAULT_HOST_CID 2
/* Max number of bytes transferred before requeueing the job.
* Using this limit prevents one virtqueue from starving others. */
#define VHOST_VSOCK_WEIGHT 0x80000
/* Max number of packets transferred before requeueing the job.
* Using this limit prevents one virtqueue from starving others with
* small pkts.
*/
#define VHOST_VSOCK_PKT_WEIGHT 256
enum {
VHOST_VSOCK_FEATURES = VHOST_FEATURES |
(1ULL << VIRTIO_F_ACCESS_PLATFORM) |
(1ULL << VIRTIO_VSOCK_F_SEQPACKET)
};
enum {
VHOST_VSOCK_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2)
};
/* Used to track all the vhost_vsock instances on the system. */
static DEFINE_MUTEX(vhost_vsock_mutex);
static DEFINE_READ_MOSTLY_HASHTABLE(vhost_vsock_hash, 8);
struct vhost_vsock {
struct vhost_dev dev;
struct vhost_virtqueue vqs[2];
/* Link to global vhost_vsock_hash, writes use vhost_vsock_mutex */
struct hlist_node hash;
struct vhost_work send_pkt_work;
struct sk_buff_head send_pkt_queue; /* host->guest pending packets */
atomic_t queued_replies;
u32 guest_cid;
bool seqpacket_allow;
};
static u32 vhost_transport_get_local_cid(void)
{
return VHOST_VSOCK_DEFAULT_HOST_CID;
}
/* Callers that dereference the return value must hold vhost_vsock_mutex or the
* RCU read lock.
*/
static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
{
struct vhost_vsock *vsock;
hash_for_each_possible_rcu(vhost_vsock_hash, vsock, hash, guest_cid) {
u32 other_cid = vsock->guest_cid;
/* Skip instances that have no CID yet */
if (other_cid == 0)
continue;
if (other_cid == guest_cid)
return vsock;
}
return NULL;
}
static void
vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
struct vhost_virtqueue *vq)
{
struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
int pkts = 0, total_len = 0;
bool added = false;
bool restart_tx = false;
mutex_lock(&vq->mutex);
if (!vhost_vq_get_backend(vq))
goto out;
if (!vq_meta_prefetch(vq))
goto out;
/* Avoid further vmexits, we're already processing the virtqueue */
vhost_disable_notify(&vsock->dev, vq);
do {
struct virtio_vsock_hdr *hdr;
size_t iov_len, payload_len;
struct iov_iter iov_iter;
u32 flags_to_restore = 0;
struct sk_buff *skb;
unsigned out, in;
size_t nbytes;
u32 offset;
int head;
skb = virtio_vsock_skb_dequeue(&vsock->send_pkt_queue);
if (!skb) {
vhost_enable_notify(&vsock->dev, vq);
break;
}
head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
&out, &in, NULL, NULL);
if (head < 0) {
virtio_vsock_skb_queue_head(&vsock->send_pkt_queue, skb);
break;
}
if (head == vq->num) {
virtio_vsock_skb_queue_head(&vsock->send_pkt_queue, skb);
/* We cannot finish yet if more buffers snuck in while
* re-enabling notify.
*/
if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
vhost_disable_notify(&vsock->dev, vq);
continue;
}
break;
}
if (out) {
kfree_skb(skb);
vq_err(vq, "Expected 0 output buffers, got %u\n", out);
break;
}
iov_len = iov_length(&vq->iov[out], in);
if (iov_len < sizeof(*hdr)) {
kfree_skb(skb);
vq_err(vq, "Buffer len [%zu] too small\n", iov_len);
break;
}
iov_iter_init(&iov_iter, ITER_DEST, &vq->iov[out], in, iov_len);
offset = VIRTIO_VSOCK_SKB_CB(skb)->offset;
payload_len = skb->len - offset;
hdr = virtio_vsock_hdr(skb);
/* If the packet is greater than the space available in the
* buffer, we split it using multiple buffers.
*/
if (payload_len > iov_len - sizeof(*hdr)) {
payload_len = iov_len - sizeof(*hdr);
/* As we are copying pieces of large packet's buffer to
* small rx buffers, headers of packets in rx queue are
* created dynamically and are initialized with header
* of current packet(except length). But in case of
* SOCK_SEQPACKET, we also must clear message delimeter
* bit (VIRTIO_VSOCK_SEQ_EOM) and MSG_EOR bit
* (VIRTIO_VSOCK_SEQ_EOR) if set. Otherwise,
* there will be sequence of packets with these
* bits set. After initialized header will be copied to
* rx buffer, these required bits will be restored.
*/
if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {
hdr->flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
flags_to_restore |= VIRTIO_VSOCK_SEQ_EOM;
if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR) {
hdr->flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
flags_to_restore |= VIRTIO_VSOCK_SEQ_EOR;
}
}
}
/* Set the correct length in the header */
hdr->len = cpu_to_le32(payload_len);
nbytes = copy_to_iter(hdr, sizeof(*hdr), &iov_iter);
if (nbytes != sizeof(*hdr)) {
kfree_skb(skb);
vq_err(vq, "Faulted on copying pkt hdr\n");
break;
}
if (skb_copy_datagram_iter(skb,
offset,
&iov_iter,
payload_len)) {
kfree_skb(skb);
vq_err(vq, "Faulted on copying pkt buf\n");
break;
}
/* Deliver to monitoring devices all packets that we
* will transmit.
*/
virtio_transport_deliver_tap_pkt(skb);
vhost_add_used(vq, head, sizeof(*hdr) + payload_len);
added = true;
VIRTIO_VSOCK_SKB_CB(skb)->offset += payload_len;
total_len += payload_len;
/* If we didn't send all the payload we can requeue the packet
* to send it with the next available buffer.
*/
if (VIRTIO_VSOCK_SKB_CB(skb)->offset < skb->len) {
hdr->flags |= cpu_to_le32(flags_to_restore);
/* We are queueing the same skb to handle
* the remaining bytes, and we want to deliver it
* to monitoring devices in the next iteration.
*/
virtio_vsock_skb_clear_tap_delivered(skb);
virtio_vsock_skb_queue_head(&vsock->send_pkt_queue, skb);
} else {
if (virtio_vsock_skb_reply(skb)) {
int val;
val = atomic_dec_return(&vsock->queued_replies);
/* Do we have resources to resume tx
* processing?
*/
if (val + 1 == tx_vq->num)
restart_tx = true;
}
virtio_transport_consume_skb_sent(skb, true);
}
} while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len)));
if (added)
vhost_signal(&vsock->dev, vq);
out:
mutex_unlock(&vq->mutex);
if (restart_tx)
vhost_poll_queue(&tx_vq->poll);
}
static void vhost_transport_send_pkt_work(struct vhost_work *work)
{
struct vhost_virtqueue *vq;
struct vhost_vsock *vsock;
vsock = container_of(work, struct vhost_vsock, send_pkt_work);
vq = &vsock->vqs[VSOCK_VQ_RX];
vhost_transport_do_send_pkt(vsock, vq);
}
static int
vhost_transport_send_pkt(struct sk_buff *skb)
{
struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
struct vhost_vsock *vsock;
int len = skb->len;
rcu_read_lock();
/* Find the vhost_vsock according to guest context id */
vsock = vhost_vsock_get(le64_to_cpu(hdr->dst_cid));
if (!vsock) {
rcu_read_unlock();
kfree_skb(skb);
return -ENODEV;
}
if (virtio_vsock_skb_reply(skb))
atomic_inc(&vsock->queued_replies);
virtio_vsock_skb_queue_tail(&vsock->send_pkt_queue, skb);
vhost_vq_work_queue(&vsock->vqs[VSOCK_VQ_RX], &vsock->send_pkt_work);
rcu_read_unlock();
return len;
}
static int
vhost_transport_cancel_pkt(struct vsock_sock *vsk)
{
struct vhost_vsock *vsock;
int cnt = 0;
int ret = -ENODEV;
rcu_read_lock();
/* Find the vhost_vsock according to guest context id */
vsock = vhost_vsock_get(vsk->remote_addr.svm_cid);
if (!vsock)
goto out;
cnt = virtio_transport_purge_skbs(vsk, &vsock->send_pkt_queue);
if (cnt) {
struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
int new_cnt;
new_cnt = atomic_sub_return(cnt, &vsock->queued_replies);
if (new_cnt + cnt >= tx_vq->num && new_cnt < tx_vq->num)
vhost_poll_queue(&tx_vq->poll);
}
ret = 0;
out:
rcu_read_unlock();
return ret;
}
static struct sk_buff *
vhost_vsock_alloc_skb(struct vhost_virtqueue *vq,
unsigned int out, unsigned int in)
{
struct virtio_vsock_hdr *hdr;
struct iov_iter iov_iter;
struct sk_buff *skb;
size_t payload_len;
size_t nbytes;
size_t len;
if (in != 0) {
vq_err(vq, "Expected 0 input buffers, got %u\n", in);
return NULL;
}
len = iov_length(vq->iov, out);
/* len contains both payload and hdr */
skb = virtio_vsock_alloc_skb(len, GFP_KERNEL);
if (!skb)
return NULL;
iov_iter_init(&iov_iter, ITER_SOURCE, vq->iov, out, len);
hdr = virtio_vsock_hdr(skb);
nbytes = copy_from_iter(hdr, sizeof(*hdr), &iov_iter);
if (nbytes != sizeof(*hdr)) {
vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n",
sizeof(*hdr), nbytes);
kfree_skb(skb);
return NULL;
}
payload_len = le32_to_cpu(hdr->len);
/* No payload */
if (!payload_len)
return skb;
/* The pkt is too big or the length in the header is invalid */
if (payload_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE ||
payload_len + sizeof(*hdr) > len) {
kfree_skb(skb);
return NULL;
}
virtio_vsock_skb_rx_put(skb);
nbytes = copy_from_iter(skb->data, payload_len, &iov_iter);
if (nbytes != payload_len) {
vq_err(vq, "Expected %zu byte payload, got %zu bytes\n",
payload_len, nbytes);
kfree_skb(skb);
return NULL;
}
return skb;
}
/* Is there space left for replies to rx packets? */
static bool vhost_vsock_more_replies(struct vhost_vsock *vsock)
{
struct vhost_virtqueue *vq = &vsock->vqs[VSOCK_VQ_TX];
int val;
smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */
val = atomic_read(&vsock->queued_replies);
return val < vq->num;
}
static bool vhost_transport_msgzerocopy_allow(void)
{
return true;
}
static bool vhost_transport_seqpacket_allow(u32 remote_cid);
static struct virtio_transport vhost_transport = {
.transport = {
.module = THIS_MODULE,
.get_local_cid = vhost_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 = vhost_transport_cancel_pkt,
.dgram_enqueue = virtio_transport_dgram_enqueue,
.dgram_dequeue = virtio_transport_dgram_dequeue,
.dgram_bind = virtio_transport_dgram_bind,
.dgram_allow = virtio_transport_dgram_allow,
.stream_enqueue = virtio_transport_stream_enqueue,
.stream_dequeue = virtio_transport_stream_dequeue,
.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,
.seqpacket_dequeue = virtio_transport_seqpacket_dequeue,
.seqpacket_enqueue = virtio_transport_seqpacket_enqueue,
.seqpacket_allow = vhost_transport_seqpacket_allow,
.seqpacket_has_data = virtio_transport_seqpacket_has_data,
.msgzerocopy_allow = vhost_transport_msgzerocopy_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,
.notify_buffer_size = virtio_transport_notify_buffer_size,
.notify_set_rcvlowat = virtio_transport_notify_set_rcvlowat,
.unsent_bytes = virtio_transport_unsent_bytes,
.read_skb = virtio_transport_read_skb,
},
.send_pkt = vhost_transport_send_pkt,
};
static bool vhost_transport_seqpacket_allow(u32 remote_cid)
{
struct vhost_vsock *vsock;
bool seqpacket_allow = false;
rcu_read_lock();
vsock = vhost_vsock_get(remote_cid);
if (vsock)
seqpacket_allow = vsock->seqpacket_allow;
rcu_read_unlock();
return seqpacket_allow;
}
static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
{
struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
poll.work);
struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
dev);
int head, pkts = 0, total_len = 0;
unsigned int out, in;
struct sk_buff *skb;
bool added = false;
mutex_lock(&vq->mutex);
if (!vhost_vq_get_backend(vq))
goto out;
if (!vq_meta_prefetch(vq))
goto out;
vhost_disable_notify(&vsock->dev, vq);
do {
struct virtio_vsock_hdr *hdr;
if (!vhost_vsock_more_replies(vsock)) {
/* Stop tx until the device processes already
* pending replies. Leave tx virtqueue
* callbacks disabled.
*/
goto no_more_replies;
}
head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
&out, &in, NULL, NULL);
if (head < 0)
break;
if (head == vq->num) {
if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
vhost_disable_notify(&vsock->dev, vq);
continue;
}
break;
}
skb = vhost_vsock_alloc_skb(vq, out, in);
if (!skb) {
vq_err(vq, "Faulted on pkt\n");
continue;
}
total_len += sizeof(*hdr) + skb->len;
/* Deliver to monitoring devices all received packets */
virtio_transport_deliver_tap_pkt(skb);
hdr = virtio_vsock_hdr(skb);
/* Only accept correctly addressed packets */
if (le64_to_cpu(hdr->src_cid) == vsock->guest_cid &&
le64_to_cpu(hdr->dst_cid) ==
vhost_transport_get_local_cid())
virtio_transport_recv_pkt(&vhost_transport, skb);
else
kfree_skb(skb);
vhost_add_used(vq, head, 0);
added = true;
} while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len)));
no_more_replies:
if (added)
vhost_signal(&vsock->dev, vq);
out:
mutex_unlock(&vq->mutex);
}
static void vhost_vsock_handle_rx_kick(struct vhost_work *work)
{
struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
poll.work);
struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
dev);
vhost_transport_do_send_pkt(vsock, vq);
}
static int vhost_vsock_start(struct vhost_vsock *vsock)
{
struct vhost_virtqueue *vq;
size_t i;
int ret;
mutex_lock(&vsock->dev.mutex);
ret = vhost_dev_check_owner(&vsock->dev);
if (ret)
goto err;
for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
vq = &vsock->vqs[i];
mutex_lock(&vq->mutex);
if (!vhost_vq_access_ok(vq)) {
ret = -EFAULT;
goto err_vq;
}
if (!vhost_vq_get_backend(vq)) {
vhost_vq_set_backend(vq, vsock);
ret = vhost_vq_init_access(vq);
if (ret)
goto err_vq;
}
mutex_unlock(&vq->mutex);
}
/* Some packets may have been queued before the device was started,
* let's kick the send worker to send them.
*/
vhost_vq_work_queue(&vsock->vqs[VSOCK_VQ_RX], &vsock->send_pkt_work);
mutex_unlock(&vsock->dev.mutex);
return 0;
err_vq:
vhost_vq_set_backend(vq, NULL);
mutex_unlock(&vq->mutex);
for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
vq = &vsock->vqs[i];
mutex_lock(&vq->mutex);
vhost_vq_set_backend(vq, NULL);
mutex_unlock(&vq->mutex);
}
err:
mutex_unlock(&vsock->dev.mutex);
return ret;
}
static int vhost_vsock_stop(struct vhost_vsock *vsock, bool check_owner)
{
size_t i;
int ret = 0;
mutex_lock(&vsock->dev.mutex);
if (check_owner) {
ret = vhost_dev_check_owner(&vsock->dev);
if (ret)
goto err;
}
for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
struct vhost_virtqueue *vq = &vsock->vqs[i];
mutex_lock(&vq->mutex);
vhost_vq_set_backend(vq, NULL);
mutex_unlock(&vq->mutex);
}
err:
mutex_unlock(&vsock->dev.mutex);
return ret;
}
static void vhost_vsock_free(struct vhost_vsock *vsock)
{
kvfree(vsock);
}
static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
{
struct vhost_virtqueue **vqs;
struct vhost_vsock *vsock;
int ret;
/* This struct is large and allocation could fail, fall back to vmalloc
* if there is no other way.
*/
vsock = kvmalloc(sizeof(*vsock), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
if (!vsock)
return -ENOMEM;
vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL);
if (!vqs) {
ret = -ENOMEM;
goto out;
}
vsock->guest_cid = 0; /* no CID assigned yet */
vsock->seqpacket_allow = false;
atomic_set(&vsock->queued_replies, 0);
vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX];
vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX];
vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick;
vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick;
vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs),
UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT,
VHOST_VSOCK_WEIGHT, true, NULL);
file->private_data = vsock;
skb_queue_head_init(&vsock->send_pkt_queue);
vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
return 0;
out:
vhost_vsock_free(vsock);
return ret;
}
static void vhost_vsock_flush(struct vhost_vsock *vsock)
{
vhost_dev_flush(&vsock->dev);
}
static void vhost_vsock_reset_orphans(struct sock *sk)
{
struct vsock_sock *vsk = vsock_sk(sk);
/* vmci_transport.c doesn't take sk_lock here either. At least we're
* under vsock_table_lock so the sock cannot disappear while we're
* executing.
*/
/* If the peer is still valid, no need to reset connection */
if (vhost_vsock_get(vsk->remote_addr.svm_cid))
return;
/* If the close timeout is pending, let it expire. This avoids races
* with the timeout callback.
*/
if (vsk->close_work_scheduled)
return;
sock_set_flag(sk, SOCK_DONE);
vsk->peer_shutdown = SHUTDOWN_MASK;
sk->sk_state = SS_UNCONNECTED;
sk->sk_err = ECONNRESET;
sk_error_report(sk);
}
static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
{
struct vhost_vsock *vsock = file->private_data;
mutex_lock(&vhost_vsock_mutex);
if (vsock->guest_cid)
hash_del_rcu(&vsock->hash);
mutex_unlock(&vhost_vsock_mutex);
/* Wait for other CPUs to finish using vsock */
synchronize_rcu();
/* Iterating over all connections for all CIDs to find orphans is
* inefficient. Room for improvement here. */
vsock_for_each_connected_socket(&vhost_transport.transport,
vhost_vsock_reset_orphans);
/* Don't check the owner, because we are in the release path, so we
* need to stop the vsock device in any case.
* vhost_vsock_stop() can not fail in this case, so we don't need to
* check the return code.
*/
vhost_vsock_stop(vsock, false);
vhost_vsock_flush(vsock);
vhost_dev_stop(&vsock->dev);
virtio_vsock_skb_queue_purge(&vsock->send_pkt_queue);
vhost_dev_cleanup(&vsock->dev);
kfree(vsock->dev.vqs);
vhost_vsock_free(vsock);
return 0;
}
static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
{
struct vhost_vsock *other;
/* Refuse reserved CIDs */
if (guest_cid <= VMADDR_CID_HOST ||
guest_cid == U32_MAX)
return -EINVAL;
/* 64-bit CIDs are not yet supported */
if (guest_cid > U32_MAX)
return -EINVAL;
/* Refuse if CID is assigned to the guest->host transport (i.e. nested
* VM), to make the loopback work.
*/
if (vsock_find_cid(guest_cid))
return -EADDRINUSE;
/* Refuse if CID is already in use */
mutex_lock(&vhost_vsock_mutex);
other = vhost_vsock_get(guest_cid);
if (other && other != vsock) {
mutex_unlock(&vhost_vsock_mutex);
return -EADDRINUSE;
}
if (vsock->guest_cid)
hash_del_rcu(&vsock->hash);
vsock->guest_cid = guest_cid;
hash_add_rcu(vhost_vsock_hash, &vsock->hash, vsock->guest_cid);
mutex_unlock(&vhost_vsock_mutex);
return 0;
}
static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features)
{
struct vhost_virtqueue *vq;
int i;
if (features & ~VHOST_VSOCK_FEATURES)
return -EOPNOTSUPP;
mutex_lock(&vsock->dev.mutex);
if ((features & (1 << VHOST_F_LOG_ALL)) &&
!vhost_log_access_ok(&vsock->dev)) {
goto err;
}
if ((features & (1ULL << VIRTIO_F_ACCESS_PLATFORM))) {
if (vhost_init_device_iotlb(&vsock->dev))
goto err;
}
vsock->seqpacket_allow = features & (1ULL << VIRTIO_VSOCK_F_SEQPACKET);
for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) {
vq = &vsock->vqs[i];
mutex_lock(&vq->mutex);
vq->acked_features = features;
mutex_unlock(&vq->mutex);
}
mutex_unlock(&vsock->dev.mutex);
return 0;
err:
mutex_unlock(&vsock->dev.mutex);
return -EFAULT;
}
static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
unsigned long arg)
{
struct vhost_vsock *vsock = f->private_data;
void __user *argp = (void __user *)arg;
u64 guest_cid;
u64 features;
int start;
int r;
switch (ioctl) {
case VHOST_VSOCK_SET_GUEST_CID:
if (copy_from_user(&guest_cid, argp, sizeof(guest_cid)))
return -EFAULT;
return vhost_vsock_set_cid(vsock, guest_cid);
case VHOST_VSOCK_SET_RUNNING:
if (copy_from_user(&start, argp, sizeof(start)))
return -EFAULT;
if (start)
return vhost_vsock_start(vsock);
else
return vhost_vsock_stop(vsock, true);
case VHOST_GET_FEATURES:
features = VHOST_VSOCK_FEATURES;
if (copy_to_user(argp, &features, sizeof(features)))
return -EFAULT;
return 0;
case VHOST_SET_FEATURES:
if (copy_from_user(&features, argp, sizeof(features)))
return -EFAULT;
return vhost_vsock_set_features(vsock, features);
case VHOST_GET_BACKEND_FEATURES:
features = VHOST_VSOCK_BACKEND_FEATURES;
if (copy_to_user(argp, &features, sizeof(features)))
return -EFAULT;
return 0;
case VHOST_SET_BACKEND_FEATURES:
if (copy_from_user(&features, argp, sizeof(features)))
return -EFAULT;
if (features & ~VHOST_VSOCK_BACKEND_FEATURES)
return -EOPNOTSUPP;
vhost_set_backend_features(&vsock->dev, features);
return 0;
default:
mutex_lock(&vsock->dev.mutex);
r = vhost_dev_ioctl(&vsock->dev, ioctl, argp);
if (r == -ENOIOCTLCMD)
r = vhost_vring_ioctl(&vsock->dev, ioctl, argp);
else
vhost_vsock_flush(vsock);
mutex_unlock(&vsock->dev.mutex);
return r;
}
}
static ssize_t vhost_vsock_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
struct file *file = iocb->ki_filp;
struct vhost_vsock *vsock = file->private_data;
struct vhost_dev *dev = &vsock->dev;
int noblock = file->f_flags & O_NONBLOCK;
return vhost_chr_read_iter(dev, to, noblock);
}
static ssize_t vhost_vsock_chr_write_iter(struct kiocb *iocb,
struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct vhost_vsock *vsock = file->private_data;
struct vhost_dev *dev = &vsock->dev;
return vhost_chr_write_iter(dev, from);
}
static __poll_t vhost_vsock_chr_poll(struct file *file, poll_table *wait)
{
struct vhost_vsock *vsock = file->private_data;
struct vhost_dev *dev = &vsock->dev;
return vhost_chr_poll(file, dev, wait);
}
static const struct file_operations vhost_vsock_fops = {
.owner = THIS_MODULE,
.open = vhost_vsock_dev_open,
.release = vhost_vsock_dev_release,
.llseek = noop_llseek,
.unlocked_ioctl = vhost_vsock_dev_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.read_iter = vhost_vsock_chr_read_iter,
.write_iter = vhost_vsock_chr_write_iter,
.poll = vhost_vsock_chr_poll,
};
static struct miscdevice vhost_vsock_misc = {
.minor = VHOST_VSOCK_MINOR,
.name = "vhost-vsock",
.fops = &vhost_vsock_fops,
};
static int __init vhost_vsock_init(void)
{
int ret;
ret = vsock_core_register(&vhost_transport.transport,
VSOCK_TRANSPORT_F_H2G);
if (ret < 0)
return ret;
ret = misc_register(&vhost_vsock_misc);
if (ret) {
vsock_core_unregister(&vhost_transport.transport);
return ret;
}
return 0;
};
static void __exit vhost_vsock_exit(void)
{
misc_deregister(&vhost_vsock_misc);
vsock_core_unregister(&vhost_transport.transport);
};
module_init(vhost_vsock_init);
module_exit(vhost_vsock_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Asias He");
MODULE_DESCRIPTION("vhost transport for vsock ");
MODULE_ALIAS_MISCDEV(VHOST_VSOCK_MINOR);
MODULE_ALIAS("devname:vhost-vsock");
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