void vhost_net_stop(struct vhost_net *net,
VirtIODevice *dev)
{
struct vhost_vring_file file = { .fd = -1 };
for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
assert(r >= 0);
}
net->vc->info->poll(net->vc, true);
vhost_dev_stop(&net->dev, dev);
if (net->dev.acked_features & (1 << VIRTIO_NET_F_MRG_RXBUF)) {
tap_set_vnet_hdr_len(net->vc, sizeof(struct virtio_net_hdr));
}
vhost_dev_disable_notifiers(&net->dev, dev);
}
void vhost_net_cleanup(struct vhost_net *net)
{
vhost_dev_cleanup(&net->dev);
if (net->dev.acked_features & (1 << VIRTIO_NET_F_MRG_RXBUF)) {
tap_set_vnet_hdr_len(net->vc, sizeof(struct virtio_net_hdr));
}
g_free(net);
}
struct vhost_net *vhost_net_init(VLANClientState *backend, int devfd)
{
int r;
struct vhost_net *net = qemu_malloc(sizeof *net);
if (!backend) {
fprintf(stderr, "vhost-net requires backend to be setup\n");
goto fail;
}
r = vhost_net_get_fd(backend);
if (r < 0) {
goto fail;
}
net->vc = backend;
net->dev.backend_features = tap_has_vnet_hdr(backend) ? 0 :
(1 << VHOST_NET_F_VIRTIO_NET_HDR);
net->backend = r;
r = vhost_dev_init(&net->dev, devfd);
if (r < 0) {
goto fail;
}
if (~net->dev.features & net->dev.backend_features) {
fprintf(stderr, "vhost lacks feature mask %" PRIu64 " for backend\n",
(uint64_t)(~net->dev.features & net->dev.backend_features));
vhost_dev_cleanup(&net->dev);
goto fail;
}
/* Set sane init value. Override when guest acks. */
vhost_net_ack_features(net, 0);
return net;
fail:
qemu_free(net);
return NULL;
}
struct vhost_net *vhost_net_init(VhostNetOptions *options)
{
int r;
bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
struct vhost_net *net = g_malloc(sizeof *net);
if (!options->net_backend) {
fprintf(stderr, "vhost-net requires net backend to be setup\n");
goto fail;
}
net->nc = options->net_backend;
net->dev.max_queues = 1;
net->dev.nvqs = 2;
net->dev.vqs = net->vqs;
if (backend_kernel) {
r = vhost_net_get_fd(options->net_backend);
if (r < 0) {
goto fail;
}
net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR);
net->backend = r;
net->dev.protocol_features = 0;
} else {
net->dev.backend_features = 0;
net->dev.protocol_features = 0;
net->backend = -1;
/* vhost-user needs vq_index to initiate a specific queue pair */
net->dev.vq_index = net->nc->queue_index * net->dev.nvqs;
}
r = vhost_dev_init(&net->dev, options->opaque,
options->backend_type);
if (r < 0) {
goto fail;
}
if (backend_kernel) {
if (!qemu_has_vnet_hdr_len(options->net_backend,
sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
}
if (~net->dev.features & net->dev.backend_features) {
fprintf(stderr, "vhost lacks feature mask %" PRIu64
" for backend\n",
(uint64_t)(~net->dev.features & net->dev.backend_features));
vhost_dev_cleanup(&net->dev);
goto fail;
}
}
/* Set sane init value. Override when guest acks. */
vhost_net_ack_features(net, 0);
return net;
fail:
g_free(net);
return NULL;
}
static void vhost_vsock_device_unrealize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostVSock *vsock = VHOST_VSOCK(dev);
vhost_vsock_post_load_timer_cleanup(vsock);
/* This will stop vhost backend if appropriate. */
vhost_vsock_set_status(vdev, 0);
vhost_dev_cleanup(&vsock->vhost_dev);
virtio_cleanup(vdev);
}
/* Caller should have device mutex */
long vhost_dev_reset_owner(struct vhost_dev *dev)
{
struct vhost_memory *memory;
/* Restore memory to default empty mapping. */
memory = kmalloc(offsetof(struct vhost_memory, regions), GFP_KERNEL);
if (!memory)
return -ENOMEM;
vhost_dev_cleanup(dev);
memory->nregions = 0;
dev->memory = memory;
return 0;
}
static void vhost_scsi_unrealize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostSCSI *s = VHOST_SCSI(dev);
migrate_del_blocker(s->migration_blocker);
error_free(s->migration_blocker);
/* This will stop vhost backend. */
vhost_scsi_set_status(vdev, 0);
vhost_dev_cleanup(&s->dev);
g_free(s->dev.vqs);
virtio_scsi_common_unrealize(dev, errp);
}
static void vhost_user_scsi_unrealize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostUserSCSI *s = VHOST_USER_SCSI(dev);
VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
struct vhost_virtqueue *vqs = vsc->dev.vqs;
/* This will stop the vhost backend. */
vhost_user_scsi_set_status(vdev, 0);
vhost_dev_cleanup(&vsc->dev);
g_free(vqs);
virtio_scsi_common_unrealize(dev, errp);
vhost_user_cleanup(&s->vhost_user);
}
void vhost_net_stop(struct vhost_net *net,
VirtIODevice *dev)
{
struct vhost_vring_file file = { .fd = -1 };
for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
int r = ioctl(net->dev.control, VHOST_NET_SET_BACKEND, &file);
assert(r >= 0);
}
net->vc->info->poll(net->vc, true);
vhost_dev_stop(&net->dev, dev);
}
void vhost_net_cleanup(struct vhost_net *net)
{
vhost_dev_cleanup(&net->dev);
qemu_free(net);
}
static int vhost_net_release(struct inode *inode, struct file *f)
{
struct vhost_net *n = f->private_data;
struct socket *tx_sock;
struct socket *rx_sock;
vhost_net_stop(n, &tx_sock, &rx_sock);
vhost_net_flush(n);
vhost_dev_cleanup(&n->dev, false);
if (tx_sock)
fput(tx_sock->file);
if (rx_sock)
fput(rx_sock->file);
/* We do an extra flush before freeing memory,
* since jobs can re-queue themselves. */
vhost_net_flush(n);
kfree(n);
return 0;
}
struct vhost_net *vhost_net_init(NetClientState *backend, int devfd,
bool force)
{
int r;
struct vhost_net *net = g_malloc(sizeof *net);
if (!backend) {
fprintf(stderr, "vhost-net requires backend to be setup\n");
goto fail;
}
r = vhost_net_get_fd(backend);
if (r < 0) {
goto fail;
}
net->nc = backend;
net->dev.backend_features = tap_has_vnet_hdr(backend) ? 0 :
(1 << VHOST_NET_F_VIRTIO_NET_HDR);
net->backend = r;
net->dev.nvqs = 2;
net->dev.vqs = net->vqs;
r = vhost_dev_init(&net->dev, devfd, "/dev/vhost-net", force);
if (r < 0) {
goto fail;
}
if (!tap_has_vnet_hdr_len(backend,
sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
net->dev.features &= ~(1 << VIRTIO_NET_F_MRG_RXBUF);
}
if (~net->dev.features & net->dev.backend_features) {
fprintf(stderr, "vhost lacks feature mask %" PRIu64 " for backend\n",
(uint64_t)(~net->dev.features & net->dev.backend_features));
vhost_dev_cleanup(&net->dev);
goto fail;
}
/* Set sane init value. Override when guest acks. */
vhost_net_ack_features(net, 0);
return net;
fail:
g_free(net);
return NULL;
}
static int vhost_net_release(struct inode *inode, struct file *f)
{
struct vhost_net *n = f->private_data;
struct socket *tx_sock;
struct socket *rx_sock;
vhost_net_stop(n, &tx_sock, &rx_sock);
vhost_net_flush(n);
vhost_dev_stop(&n->dev);
vhost_dev_cleanup(&n->dev, false);
vhost_net_vq_reset(n);
if (tx_sock)
sockfd_put(tx_sock);
if (rx_sock)
sockfd_put(rx_sock);
/* Make sure no callbacks are outstanding */
synchronize_rcu_bh();
/* We do an extra flush before freeing memory,
* since jobs can re-queue themselves. */
vhost_net_flush(n);
kfree(n->dev.vqs);
kvfree(n);
return 0;
}
void vhost_net_cleanup(struct vhost_net *net)
{
vhost_dev_cleanup(&net->dev);
g_free(net);
}
static void vhost_vsock_device_realize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VHostVSock *vsock = VHOST_VSOCK(dev);
int vhostfd;
int ret;
/* Refuse to use reserved CID numbers */
if (vsock->conf.guest_cid <= 2) {
error_setg(errp, "guest-cid property must be greater than 2");
return;
}
if (vsock->conf.guest_cid > UINT32_MAX) {
error_setg(errp, "guest-cid property must be a 32-bit number");
return;
}
if (vsock->conf.vhostfd) {
vhostfd = monitor_fd_param(cur_mon, vsock->conf.vhostfd, errp);
if (vhostfd == -1) {
error_prepend(errp, "vhost-vsock: unable to parse vhostfd: ");
return;
}
} else {
vhostfd = open("/dev/vhost-vsock", O_RDWR);
if (vhostfd < 0) {
error_setg_errno(errp, -errno,
"vhost-vsock: failed to open vhost device");
return;
}
}
virtio_init(vdev, "vhost-vsock", VIRTIO_ID_VSOCK,
sizeof(struct virtio_vsock_config));
/* Receive and transmit queues belong to vhost */
virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output);
virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output);
/* The event queue belongs to QEMU */
vsock->event_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
vhost_vsock_handle_output);
vsock->vhost_dev.nvqs = ARRAY_SIZE(vsock->vhost_vqs);
vsock->vhost_dev.vqs = vsock->vhost_vqs;
ret = vhost_dev_init(&vsock->vhost_dev, (void *)(uintptr_t)vhostfd,
VHOST_BACKEND_TYPE_KERNEL, 0);
if (ret < 0) {
error_setg_errno(errp, -ret, "vhost-vsock: vhost_dev_init failed");
goto err_virtio;
}
ret = vhost_vsock_set_guest_cid(vsock);
if (ret < 0) {
error_setg_errno(errp, -ret, "vhost-vsock: unable to set guest cid");
goto err_vhost_dev;
}
vsock->post_load_timer = NULL;
return;
err_vhost_dev:
vhost_dev_cleanup(&vsock->vhost_dev);
err_virtio:
virtio_cleanup(vdev);
close(vhostfd);
return;
}
/* Expects to be always run from workqueue - which acts as
* read-size critical section for our kind of RCU. */
static void handle_rx_big(struct vhost_net *net)
{
struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
unsigned out, in, log, s;
int head;
struct vhost_log *vq_log;
struct msghdr msg = {
.msg_name = NULL,
.msg_namelen = 0,
.msg_control = NULL, /* FIXME: get and handle RX aux data. */
.msg_controllen = 0,
.msg_iov = vq->iov,
.msg_flags = MSG_DONTWAIT,
};
struct virtio_net_hdr hdr = {
.flags = 0,
.gso_type = VIRTIO_NET_HDR_GSO_NONE
};
size_t len, total_len = 0;
int err;
size_t hdr_size;
struct socket *sock = rcu_dereference(vq->private_data);
if (!sock || skb_queue_empty(&sock->sk->sk_receive_queue))
return;
use_mm(net->dev.mm);
mutex_lock(&vq->mutex);
vhost_disable_notify(vq);
hdr_size = vq->vhost_hlen;
vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
vq->log : NULL;
for (;;) {
head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
ARRAY_SIZE(vq->iov),
&out, &in,
vq_log, &log);
/* On error, stop handling until the next kick. */
if (unlikely(head < 0))
break;
/* OK, now we need to know about added descriptors. */
if (head == vq->num) {
if (unlikely(vhost_enable_notify(vq))) {
/* They have slipped one in as we were
* doing that: check again. */
vhost_disable_notify(vq);
continue;
}
/* Nothing new? Wait for eventfd to tell us
* they refilled. */
break;
}
/* We don't need to be notified again. */
if (out) {
vq_err(vq, "Unexpected descriptor format for RX: "
"out %d, int %d\n",
out, in);
break;
}
/* Skip header. TODO: support TSO/mergeable rx buffers. */
s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, in);
msg.msg_iovlen = in;
len = iov_length(vq->iov, in);
/* Sanity check */
if (!len) {
vq_err(vq, "Unexpected header len for RX: "
"%zd expected %zd\n",
iov_length(vq->hdr, s), hdr_size);
break;
}
err = sock->ops->recvmsg(NULL, sock, &msg,
len, MSG_DONTWAIT | MSG_TRUNC);
/* TODO: Check specific error and bomb out unless EAGAIN? */
if (err < 0) {
vhost_discard_vq_desc(vq, 1);
break;
}
/* TODO: Should check and handle checksum. */
if (err > len) {
pr_debug("Discarded truncated rx packet: "
" len %d > %zd\n", err, len);
vhost_discard_vq_desc(vq, 1);
continue;
}
len = err;
err = memcpy_toiovec(vq->hdr, (unsigned char *)&hdr, hdr_size);
if (err) {
vq_err(vq, "Unable to write vnet_hdr at addr %p: %d\n",
vq->iov->iov_base, err);
break;
}
len += hdr_size;
vhost_add_used_and_signal(&net->dev, vq, head, len);
if (unlikely(vq_log))
vhost_log_write(vq, vq_log, log, len);
total_len += len;
if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
vhost_poll_queue(&vq->poll);
break;
}
}
mutex_unlock(&vq->mutex);
unuse_mm(net->dev.mm);
}
/* Expects to be always run from workqueue - which acts as
* read-size critical section for our kind of RCU. */
static void handle_rx_mergeable(struct vhost_net *net)
{
struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
unsigned uninitialized_var(in), log;
struct vhost_log *vq_log;
struct msghdr msg = {
.msg_name = NULL,
.msg_namelen = 0,
.msg_control = NULL, /* FIXME: get and handle RX aux data. */
.msg_controllen = 0,
.msg_iov = vq->iov,
.msg_flags = MSG_DONTWAIT,
};
struct virtio_net_hdr_mrg_rxbuf hdr = {
.hdr.flags = 0,
.hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE
};
size_t total_len = 0;
int err, headcount;
size_t vhost_hlen, sock_hlen;
size_t vhost_len, sock_len;
struct socket *sock = rcu_dereference(vq->private_data);
if (!sock || skb_queue_empty(&sock->sk->sk_receive_queue))
return;
use_mm(net->dev.mm);
mutex_lock(&vq->mutex);
vhost_disable_notify(vq);
vhost_hlen = vq->vhost_hlen;
sock_hlen = vq->sock_hlen;
vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
vq->log : NULL;
while ((sock_len = peek_head_len(sock->sk))) {
sock_len += sock_hlen;
vhost_len = sock_len + vhost_hlen;
headcount = get_rx_bufs(vq, vq->heads, vhost_len,
&in, vq_log, &log);
/* On error, stop handling until the next kick. */
if (unlikely(headcount < 0))
break;
/* OK, now we need to know about added descriptors. */
if (!headcount) {
if (unlikely(vhost_enable_notify(vq))) {
/* They have slipped one in as we were
* doing that: check again. */
vhost_disable_notify(vq);
continue;
}
/* Nothing new? Wait for eventfd to tell us
* they refilled. */
break;
}
/* We don't need to be notified again. */
if (unlikely((vhost_hlen)))
/* Skip header. TODO: support TSO. */
move_iovec_hdr(vq->iov, vq->hdr, vhost_hlen, in);
else
/* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
* needed because sendmsg can modify msg_iov. */
copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in);
msg.msg_iovlen = in;
err = sock->ops->recvmsg(NULL, sock, &msg,
sock_len, MSG_DONTWAIT | MSG_TRUNC);
/* Userspace might have consumed the packet meanwhile:
* it's not supposed to do this usually, but might be hard
* to prevent. Discard data we got (if any) and keep going. */
if (unlikely(err != sock_len)) {
pr_debug("Discarded rx packet: "
" len %d, expected %zd\n", err, sock_len);
vhost_discard_vq_desc(vq, headcount);
continue;
}
if (unlikely(vhost_hlen) &&
memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0,
vhost_hlen)) {
vq_err(vq, "Unable to write vnet_hdr at addr %p\n",
vq->iov->iov_base);
break;
}
/* TODO: Should check and handle checksum. */
if (vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF) &&
memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount,
offsetof(typeof(hdr), num_buffers),
sizeof hdr.num_buffers)) {
vq_err(vq, "Failed num_buffers write");
vhost_discard_vq_desc(vq, headcount);
break;
}
vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
headcount);
if (unlikely(vq_log))
vhost_log_write(vq, vq_log, log, vhost_len);
total_len += vhost_len;
if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
vhost_poll_queue(&vq->poll);
break;
}
}
mutex_unlock(&vq->mutex);
unuse_mm(net->dev.mm);
}
static void handle_rx(struct vhost_net *net)
{
if (vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF))
handle_rx_mergeable(net);
else
handle_rx_big(net);
}
static void handle_tx_kick(struct vhost_work *work)
{
struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
poll.work);
struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
handle_tx(net);
}
static void handle_rx_kick(struct vhost_work *work)
{
struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
poll.work);
struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);
handle_rx(net);
}
static void handle_tx_net(struct vhost_work *work)
{
struct vhost_net *net = container_of(work, struct vhost_net,
poll[VHOST_NET_VQ_TX].work);
handle_tx(net);
}
static void handle_rx_net(struct vhost_work *work)
{
struct vhost_net *net = container_of(work, struct vhost_net,
poll[VHOST_NET_VQ_RX].work);
handle_rx(net);
}
static int vhost_net_open(struct inode *inode, struct file *f)
{
struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
struct vhost_dev *dev;
int r;
if (!n)
return -ENOMEM;
dev = &n->dev;
n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick;
n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick;
r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX);
if (r < 0) {
kfree(n);
return r;
}
vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
n->tx_poll_state = VHOST_NET_POLL_DISABLED;
f->private_data = n;
return 0;
}
static void vhost_net_disable_vq(struct vhost_net *n,
struct vhost_virtqueue *vq)
{
if (!vq->private_data)
return;
if (vq == n->vqs + VHOST_NET_VQ_TX) {
tx_poll_stop(n);
n->tx_poll_state = VHOST_NET_POLL_DISABLED;
} else
vhost_poll_stop(n->poll + VHOST_NET_VQ_RX);
}
static void vhost_net_enable_vq(struct vhost_net *n,
struct vhost_virtqueue *vq)
{
struct socket *sock;
sock = rcu_dereference_protected(vq->private_data,
lockdep_is_held(&vq->mutex));
if (!sock)
return;
if (vq == n->vqs + VHOST_NET_VQ_TX) {
n->tx_poll_state = VHOST_NET_POLL_STOPPED;
tx_poll_start(n, sock);
} else
vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file);
}
static struct socket *vhost_net_stop_vq(struct vhost_net *n,
struct vhost_virtqueue *vq)
{
struct socket *sock;
mutex_lock(&vq->mutex);
sock = rcu_dereference_protected(vq->private_data,
lockdep_is_held(&vq->mutex));
vhost_net_disable_vq(n, vq);
rcu_assign_pointer(vq->private_data, NULL);
mutex_unlock(&vq->mutex);
return sock;
}
static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
struct socket **rx_sock)
{
*tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX);
*rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX);
}
static void vhost_net_flush_vq(struct vhost_net *n, int index)
{
vhost_poll_flush(n->poll + index);
vhost_poll_flush(&n->dev.vqs[index].poll);
}
static void vhost_net_flush(struct vhost_net *n)
{
vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
}
static int vhost_net_release(struct inode *inode, struct file *f)
{
struct vhost_net *n = f->private_data;
struct socket *tx_sock;
struct socket *rx_sock;
vhost_net_stop(n, &tx_sock, &rx_sock);
vhost_net_flush(n);
vhost_dev_cleanup(&n->dev);
if (tx_sock)
fput(tx_sock->file);
if (rx_sock)
fput(rx_sock->file);
/* We do an extra flush before freeing memory,
* since jobs can re-queue themselves. */
vhost_net_flush(n);
kfree(n);
return 0;
}
static struct socket *get_raw_socket(int fd)
{
struct {
struct sockaddr_ll sa;
char buf[MAX_ADDR_LEN];
} uaddr;
int uaddr_len = sizeof uaddr, r;
struct socket *sock = sockfd_lookup(fd, &r);
if (!sock)
return ERR_PTR(-ENOTSOCK);
/* Parameter checking */
if (sock->sk->sk_type != SOCK_RAW) {
r = -ESOCKTNOSUPPORT;
goto err;
}
r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa,
&uaddr_len, 0);
if (r)
goto err;
if (uaddr.sa.sll_family != AF_PACKET) {
r = -EPFNOSUPPORT;
goto err;
}
return sock;
err:
fput(sock->file);
return ERR_PTR(r);
}
static struct socket *get_tap_socket(int fd)
{
struct file *file = fget(fd);
struct socket *sock;
if (!file)
return ERR_PTR(-EBADF);
sock = tun_get_socket(file);
if (!IS_ERR(sock))
return sock;
sock = macvtap_get_socket(file);
if (IS_ERR(sock))
fput(file);
return sock;
}
static struct socket *get_socket(int fd)
{
struct socket *sock;
/* special case to disable backend */
if (fd == -1)
return NULL;
sock = get_raw_socket(fd);
if (!IS_ERR(sock))
return sock;
sock = get_tap_socket(fd);
if (!IS_ERR(sock))
return sock;
return ERR_PTR(-ENOTSOCK);
}
static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
{
struct socket *sock, *oldsock;
struct vhost_virtqueue *vq;
int r;
mutex_lock(&n->dev.mutex);
r = vhost_dev_check_owner(&n->dev);
if (r)
goto err;
if (index >= VHOST_NET_VQ_MAX) {
r = -ENOBUFS;
goto err;
}
vq = n->vqs + index;
mutex_lock(&vq->mutex);
/* Verify that ring has been setup correctly. */
if (!vhost_vq_access_ok(vq)) {
r = -EFAULT;
goto err_vq;
}
sock = get_socket(fd);
if (IS_ERR(sock)) {
r = PTR_ERR(sock);
goto err_vq;
}
/* start polling new socket */
oldsock = rcu_dereference_protected(vq->private_data,
lockdep_is_held(&vq->mutex));
if (sock != oldsock) {
vhost_net_disable_vq(n, vq);
rcu_assign_pointer(vq->private_data, sock);
vhost_net_enable_vq(n, vq);
}
mutex_unlock(&vq->mutex);
if (oldsock) {
vhost_net_flush_vq(n, index);
fput(oldsock->file);
}
mutex_unlock(&n->dev.mutex);
return 0;
err_vq:
mutex_unlock(&vq->mutex);
err:
mutex_unlock(&n->dev.mutex);
return r;
}
static long vhost_net_reset_owner(struct vhost_net *n)
{
struct socket *tx_sock = NULL;
struct socket *rx_sock = NULL;
long err;
mutex_lock(&n->dev.mutex);
err = vhost_dev_check_owner(&n->dev);
if (err)
goto done;
vhost_net_stop(n, &tx_sock, &rx_sock);
vhost_net_flush(n);
err = vhost_dev_reset_owner(&n->dev);
done:
mutex_unlock(&n->dev.mutex);
if (tx_sock)
fput(tx_sock->file);
if (rx_sock)
fput(rx_sock->file);
return err;
}
static int vhost_net_set_features(struct vhost_net *n, u64 features)
{
size_t vhost_hlen, sock_hlen, hdr_len;
int i;
hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
sizeof(struct virtio_net_hdr_mrg_rxbuf) :
sizeof(struct virtio_net_hdr);
if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
/* vhost provides vnet_hdr */
vhost_hlen = hdr_len;
sock_hlen = 0;
} else {
/* socket provides vnet_hdr */
vhost_hlen = 0;
sock_hlen = hdr_len;
}
mutex_lock(&n->dev.mutex);
if ((features & (1 << VHOST_F_LOG_ALL)) &&
!vhost_log_access_ok(&n->dev)) {
mutex_unlock(&n->dev.mutex);
return -EFAULT;
}
n->dev.acked_features = features;
smp_wmb();
for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
mutex_lock(&n->vqs[i].mutex);
n->vqs[i].vhost_hlen = vhost_hlen;
n->vqs[i].sock_hlen = sock_hlen;
mutex_unlock(&n->vqs[i].mutex);
}
vhost_net_flush(n);
mutex_unlock(&n->dev.mutex);
return 0;
}
