linux/drivers/vhost/vsock.c
Jiyong Park 8e6ed96376 vsock: each transport cycles only on its own sockets
When iterating over sockets using vsock_for_each_connected_socket, make
sure that a transport filters out sockets that don't belong to the
transport.

There actually was an issue caused by this; in a nested VM
configuration, destroying the nested VM (which often involves the
closing of /dev/vhost-vsock if there was h2g connections to the nested
VM) kills not only the h2g connections, but also all existing g2h
connections to the (outmost) host which are totally unrelated.

Tested: Executed the following steps on Cuttlefish (Android running on a
VM) [1]: (1) Enter into an `adb shell` session - to have a g2h
connection inside the VM, (2) open and then close /dev/vhost-vsock by
`exec 3< /dev/vhost-vsock && exec 3<&-`, (3) observe that the adb
session is not reset.

[1] https://android.googlesource.com/device/google/cuttlefish/

Fixes: c0cfa2d8a7 ("vsock: add multi-transports support")
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jiyong Park <jiyong@google.com>
Link: https://lore.kernel.org/r/20220311020017.1509316-1-jiyong@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-11 23:14:19 -08:00

983 lines
25 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* vhost transport for vsock
*
* Copyright (C) 2013-2015 Red Hat, Inc.
* Author: Asias He <asias@redhat.com>
* Stefan Hajnoczi <stefanha@redhat.com>
*/
#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;
spinlock_t send_pkt_list_lock;
struct list_head send_pkt_list; /* 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_pkt *pkt;
struct iov_iter iov_iter;
unsigned out, in;
size_t nbytes;
size_t iov_len, payload_len;
int head;
u32 flags_to_restore = 0;
spin_lock_bh(&vsock->send_pkt_list_lock);
if (list_empty(&vsock->send_pkt_list)) {
spin_unlock_bh(&vsock->send_pkt_list_lock);
vhost_enable_notify(&vsock->dev, vq);
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);
head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
&out, &in, NULL, NULL);
if (head < 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 (head == vq->num) {
spin_lock_bh(&vsock->send_pkt_list_lock);
list_add(&pkt->list, &vsock->send_pkt_list);
spin_unlock_bh(&vsock->send_pkt_list_lock);
/* 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) {
virtio_transport_free_pkt(pkt);
vq_err(vq, "Expected 0 output buffers, got %u\n", out);
break;
}
iov_len = iov_length(&vq->iov[out], in);
if (iov_len < sizeof(pkt->hdr)) {
virtio_transport_free_pkt(pkt);
vq_err(vq, "Buffer len [%zu] too small\n", iov_len);
break;
}
iov_iter_init(&iov_iter, READ, &vq->iov[out], in, iov_len);
payload_len = pkt->len - pkt->off;
/* If the packet is greater than the space available in the
* buffer, we split it using multiple buffers.
*/
if (payload_len > iov_len - sizeof(pkt->hdr)) {
payload_len = iov_len - sizeof(pkt->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(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM) {
pkt->hdr.flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
flags_to_restore |= VIRTIO_VSOCK_SEQ_EOM;
if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR) {
pkt->hdr.flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
flags_to_restore |= VIRTIO_VSOCK_SEQ_EOR;
}
}
}
/* Set the correct length in the header */
pkt->hdr.len = cpu_to_le32(payload_len);
nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
if (nbytes != sizeof(pkt->hdr)) {
virtio_transport_free_pkt(pkt);
vq_err(vq, "Faulted on copying pkt hdr\n");
break;
}
nbytes = copy_to_iter(pkt->buf + pkt->off, payload_len,
&iov_iter);
if (nbytes != payload_len) {
virtio_transport_free_pkt(pkt);
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(pkt);
vhost_add_used(vq, head, sizeof(pkt->hdr) + payload_len);
added = true;
pkt->off += 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 (pkt->off < pkt->len) {
pkt->hdr.flags |= cpu_to_le32(flags_to_restore);
/* We are queueing the same virtio_vsock_pkt to handle
* the remaining bytes, and we want to deliver it
* to monitoring devices in the next iteration.
*/
pkt->tap_delivered = false;
spin_lock_bh(&vsock->send_pkt_list_lock);
list_add(&pkt->list, &vsock->send_pkt_list);
spin_unlock_bh(&vsock->send_pkt_list_lock);
} else {
if (pkt->reply) {
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_free_pkt(pkt);
}
} 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 virtio_vsock_pkt *pkt)
{
struct vhost_vsock *vsock;
int len = pkt->len;
rcu_read_lock();
/* Find the vhost_vsock according to guest context id */
vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid));
if (!vsock) {
rcu_read_unlock();
virtio_transport_free_pkt(pkt);
return -ENODEV;
}
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);
vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
rcu_read_unlock();
return len;
}
static int
vhost_transport_cancel_pkt(struct vsock_sock *vsk)
{
struct vhost_vsock *vsock;
struct virtio_vsock_pkt *pkt, *n;
int cnt = 0;
int ret = -ENODEV;
LIST_HEAD(freeme);
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;
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 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 virtio_vsock_pkt *
vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
unsigned int out, unsigned int in)
{
struct virtio_vsock_pkt *pkt;
struct iov_iter iov_iter;
size_t nbytes;
size_t len;
if (in != 0) {
vq_err(vq, "Expected 0 input buffers, got %u\n", in);
return NULL;
}
pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
if (!pkt)
return NULL;
len = iov_length(vq->iov, out);
iov_iter_init(&iov_iter, WRITE, vq->iov, out, len);
nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
if (nbytes != sizeof(pkt->hdr)) {
vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n",
sizeof(pkt->hdr), nbytes);
kfree(pkt);
return NULL;
}
pkt->len = le32_to_cpu(pkt->hdr.len);
/* No payload */
if (!pkt->len)
return pkt;
/* The pkt is too big */
if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
kfree(pkt);
return NULL;
}
pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
if (!pkt->buf) {
kfree(pkt);
return NULL;
}
pkt->buf_len = pkt->len;
nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter);
if (nbytes != pkt->len) {
vq_err(vq, "Expected %u byte payload, got %zu bytes\n",
pkt->len, nbytes);
virtio_transport_free_pkt(pkt);
return NULL;
}
return pkt;
}
/* 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_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,
.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,
},
.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);
struct virtio_vsock_pkt *pkt;
int head, pkts = 0, total_len = 0;
unsigned int out, in;
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 {
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;
}
pkt = vhost_vsock_alloc_pkt(vq, out, in);
if (!pkt) {
vq_err(vq, "Faulted on pkt\n");
continue;
}
total_len += sizeof(pkt->hdr) + pkt->len;
/* Deliver to monitoring devices all received packets */
virtio_transport_deliver_tap_pkt(pkt);
/* Only accept correctly addressed packets */
if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid &&
le64_to_cpu(pkt->hdr.dst_cid) ==
vhost_transport_get_local_cid())
virtio_transport_recv_pkt(&vhost_transport, pkt);
else
virtio_transport_free_pkt(pkt);
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_work_queue(&vsock->dev, &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 */
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;
spin_lock_init(&vsock->send_pkt_list_lock);
INIT_LIST_HEAD(&vsock->send_pkt_list);
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)
{
int i;
for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++)
if (vsock->vqs[i].handle_kick)
vhost_poll_flush(&vsock->vqs[i].poll);
vhost_work_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);
spin_lock_bh(&vsock->send_pkt_list_lock);
while (!list_empty(&vsock->send_pkt_list)) {
struct virtio_vsock_pkt *pkt;
pkt = list_first_entry(&vsock->send_pkt_list,
struct virtio_vsock_pkt, list);
list_del_init(&pkt->list);
virtio_transport_free_pkt(pkt);
}
spin_unlock_bh(&vsock->send_pkt_list_lock);
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, true))
goto err;
}
if (features & (1ULL << VIRTIO_VSOCK_F_SEQPACKET))
vsock->seqpacket_allow = true;
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;
return misc_register(&vhost_vsock_misc);
};
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");