Commit c0cfa2d8 authored by Stefano Garzarella's avatar Stefano Garzarella Committed by David S. Miller
Browse files

vsock: add multi-transports support 



This patch adds the support of multiple transports in the
VSOCK core.

With the multi-transports support, we can use vsock with nested VMs
(using also different hypervisors) loading both guest->host and
host->guest transports at the same time.

Major changes:
- vsock core module can be loaded regardless of the transports
- vsock_core_init() and vsock_core_exit() are renamed to
  vsock_core_register() and vsock_core_unregister()
- vsock_core_register() has a feature parameter (H2G, G2H, DGRAM)
  to identify which directions the transport can handle and if it's
  support DGRAM (only vmci)
- each stream socket is assigned to a transport when the remote CID
  is set (during the connect() or when we receive a connection request
  on a listener socket).
  The remote CID is used to decide which transport to use:
  - remote CID <= VMADDR_CID_HOST will use guest->host transport;
  - remote CID == local_cid (guest->host transport) will use guest->host
    transport for loopback (host->guest transports don't support loopback);
  - remote CID > VMADDR_CID_HOST will use host->guest transport;
- listener sockets are not bound to any transports since no transport
  operations are done on it. In this way we can create a listener
  socket, also if the transports are not loaded or with VMADDR_CID_ANY
  to listen on all transports.
- DGRAM sockets are handled as before, since only the vmci_transport
  provides this feature.

Signed-off-by: default avatarStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 03964257

drivers/vhost/vsock.c

+3 −2
Original line number Diff line number Diff line
@@ -831,7 +831,8 @@ static int __init vhost_vsock_init(void) 
{

	int ret;



	ret = vsock_core_init(&vhost_transport.transport);

	ret = vsock_core_register(&vhost_transport.transport,

				  VSOCK_TRANSPORT_F_H2G);

	if (ret < 0)

		return ret;

	return misc_register(&vhost_vsock_misc);
@@ -840,7 +841,7 @@ static int __init vhost_vsock_init(void) 
static void __exit vhost_vsock_exit(void)

{

	misc_deregister(&vhost_vsock_misc);

	vsock_core_exit();

	vsock_core_unregister(&vhost_transport.transport);

};



module_init(vhost_vsock_init);

include/net/af_vsock.h

+12 −6
Original line number Diff line number Diff line
@@ -91,6 +91,14 @@ struct vsock_transport_send_notify_data { 
	u64 data2; /* Transport-defined. */

};



/* Transport features flags */

/* Transport provides host->guest communication */

#define VSOCK_TRANSPORT_F_H2G		0x00000001

/* Transport provides guest->host communication */

#define VSOCK_TRANSPORT_F_G2H		0x00000002

/* Transport provides DGRAM communication */

#define VSOCK_TRANSPORT_F_DGRAM		0x00000004



struct vsock_transport {

	/* Initialize/tear-down socket. */

	int (*init)(struct vsock_sock *, struct vsock_sock *);
@@ -154,12 +162,8 @@ struct vsock_transport { 


/**** CORE ****/



int __vsock_core_init(const struct vsock_transport *t, struct module *owner);

static inline int vsock_core_init(const struct vsock_transport *t)

{

	return __vsock_core_init(t, THIS_MODULE);

}

void vsock_core_exit(void);

int vsock_core_register(const struct vsock_transport *t, int features);

void vsock_core_unregister(const struct vsock_transport *t);



/* The transport may downcast this to access transport-specific functions */

const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk);
@@ -190,6 +194,8 @@ struct sock *vsock_find_connected_socket(struct sockaddr_vm *src, 
					 struct sockaddr_vm *dst);

void vsock_remove_sock(struct vsock_sock *vsk);

void vsock_for_each_connected_socket(void (*fn)(struct sock *sk));

int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);

bool vsock_find_cid(unsigned int cid);



/**** TAP ****/

net/vmw_vsock/af_vsock.c

+184 −59
Original line number Diff line number Diff line
@@ -130,7 +130,12 @@ static struct proto vsock_proto = { 
#define VSOCK_DEFAULT_BUFFER_MAX_SIZE (1024 * 256)

#define VSOCK_DEFAULT_BUFFER_MIN_SIZE 128



static const struct vsock_transport *transport_single;

/* Transport used for host->guest communication */

static const struct vsock_transport *transport_h2g;

/* Transport used for guest->host communication */

static const struct vsock_transport *transport_g2h;

/* Transport used for DGRAM communication */

static const struct vsock_transport *transport_dgram;

static DEFINE_MUTEX(vsock_register_mutex);



/**** UTILS ****/
@@ -182,7 +187,7 @@ static int vsock_auto_bind(struct vsock_sock *vsk) 
	return __vsock_bind(sk, &local_addr);

}



static int __init vsock_init_tables(void)

static void vsock_init_tables(void)

{

	int i;
@@ -191,7 +196,6 @@ static int __init vsock_init_tables(void) 


	for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)

		INIT_LIST_HEAD(&vsock_connected_table[i]);

	return 0;

}



static void __vsock_insert_bound(struct list_head *list,
@@ -376,6 +380,68 @@ void vsock_enqueue_accept(struct sock *listener, struct sock *connected) 
}

EXPORT_SYMBOL_GPL(vsock_enqueue_accept);



/* Assign a transport to a socket and call the .init transport callback.

 *

 * Note: for stream socket this must be called when vsk->remote_addr is set

 * (e.g. during the connect() or when a connection request on a listener

 * socket is received).

 * The vsk->remote_addr is used to decide which transport to use:

 *  - remote CID <= VMADDR_CID_HOST will use guest->host transport;

 *  - remote CID == local_cid (guest->host transport) will use guest->host

 *    transport for loopback (host->guest transports don't support loopback);

 *  - remote CID > VMADDR_CID_HOST will use host->guest transport;

 */

int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)

{

	const struct vsock_transport *new_transport;

	struct sock *sk = sk_vsock(vsk);

	unsigned int remote_cid = vsk->remote_addr.svm_cid;



	switch (sk->sk_type) {

	case SOCK_DGRAM:

		new_transport = transport_dgram;

		break;

	case SOCK_STREAM:

		if (remote_cid <= VMADDR_CID_HOST ||

		    (transport_g2h &&

		     remote_cid == transport_g2h->get_local_cid()))

			new_transport = transport_g2h;

		else

			new_transport = transport_h2g;

		break;

	default:

		return -ESOCKTNOSUPPORT;

	}



	if (vsk->transport) {

		if (vsk->transport == new_transport)

			return 0;



		vsk->transport->release(vsk);

		vsk->transport->destruct(vsk);

	}



	if (!new_transport)

		return -ENODEV;



	vsk->transport = new_transport;



	return vsk->transport->init(vsk, psk);

}

EXPORT_SYMBOL_GPL(vsock_assign_transport);



bool vsock_find_cid(unsigned int cid)

{

	if (transport_g2h && cid == transport_g2h->get_local_cid())

		return true;



	if (transport_h2g && cid == VMADDR_CID_HOST)

		return true;



	return false;

}

EXPORT_SYMBOL_GPL(vsock_find_cid);



static struct sock *vsock_dequeue_accept(struct sock *listener)

{

	struct vsock_sock *vlistener;
@@ -414,6 +480,9 @@ static int vsock_send_shutdown(struct sock *sk, int mode) 
{

	struct vsock_sock *vsk = vsock_sk(sk);



	if (!vsk->transport)

		return -ENODEV;



	return vsk->transport->shutdown(vsk, mode);

}
@@ -530,7 +599,6 @@ static int __vsock_bind_dgram(struct vsock_sock *vsk, 
static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)

{

	struct vsock_sock *vsk = vsock_sk(sk);

	u32 cid;

	int retval;



	/* First ensure this socket isn't already bound. */
@@ -540,10 +608,9 @@ static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr) 
	/* Now bind to the provided address or select appropriate values if

	 * none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY).  Note that

	 * like AF_INET prevents binding to a non-local IP address (in most

	 * cases), we only allow binding to the local CID.

	 * cases), we only allow binding to a local CID.

	 */

	cid = vsk->transport->get_local_cid();

	if (addr->svm_cid != cid && addr->svm_cid != VMADDR_CID_ANY)

	if (addr->svm_cid != VMADDR_CID_ANY && !vsock_find_cid(addr->svm_cid))

		return -EADDRNOTAVAIL;



	switch (sk->sk_socket->type) {
@@ -592,7 +659,6 @@ static struct sock *__vsock_create(struct net *net, 
		sk->sk_type = type;



	vsk = vsock_sk(sk);

	vsk->transport = transport_single;

	vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);

	vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
@@ -629,11 +695,6 @@ static struct sock *__vsock_create(struct net *net, 
		vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE;

	}



	if (vsk->transport->init(vsk, psk) < 0) {

		sk_free(sk);

		return NULL;

	}



	return sk;

}
@@ -649,7 +710,10 @@ static void __vsock_release(struct sock *sk, int level) 
		/* The release call is supposed to use lock_sock_nested()

		 * rather than lock_sock(), if a sock lock should be acquired.

		 */

		if (vsk->transport)

			vsk->transport->release(vsk);

		else if (sk->sk_type == SOCK_STREAM)

			vsock_remove_sock(vsk);



		/* When "level" is SINGLE_DEPTH_NESTING, use the nested

		 * version to avoid the warning "possible recursive locking
@@ -677,6 +741,7 @@ static void vsock_sk_destruct(struct sock *sk) 
{

	struct vsock_sock *vsk = vsock_sk(sk);



	if (vsk->transport)

		vsk->transport->destruct(vsk);



	/* When clearing these addresses, there's no need to set the family and
@@ -894,7 +959,7 @@ static __poll_t vsock_poll(struct file *file, struct socket *sock, 
			mask |= EPOLLIN | EPOLLRDNORM;



		/* If there is something in the queue then we can read. */

		if (transport->stream_is_active(vsk) &&

		if (transport && transport->stream_is_active(vsk) &&

		    !(sk->sk_shutdown & RCV_SHUTDOWN)) {

			bool data_ready_now = false;

			int ret = transport->notify_poll_in(
@@ -1144,7 +1209,6 @@ static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr, 
	err = 0;

	sk = sock->sk;

	vsk = vsock_sk(sk);

	transport = vsk->transport;



	lock_sock(sk);
@@ -1172,19 +1236,26 @@ static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr, 
			goto out;

		}



		/* Set the remote address that we are connecting to. */

		memcpy(&vsk->remote_addr, remote_addr,

		       sizeof(vsk->remote_addr));



		err = vsock_assign_transport(vsk, NULL);

		if (err)

			goto out;



		transport = vsk->transport;



		/* The hypervisor and well-known contexts do not have socket

		 * endpoints.

		 */

		if (!transport->stream_allow(remote_addr->svm_cid,

		if (!transport ||

		    !transport->stream_allow(remote_addr->svm_cid,

					     remote_addr->svm_port)) {

			err = -ENETUNREACH;

			goto out;

		}



		/* Set the remote address that we are connecting to. */

		memcpy(&vsk->remote_addr, remote_addr,

		       sizeof(vsk->remote_addr));



		err = vsock_auto_bind(vsk);

		if (err)

			goto out;
@@ -1584,7 +1655,7 @@ static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg, 
		goto out;

	}



	if (sk->sk_state != TCP_ESTABLISHED ||

	if (!transport || sk->sk_state != TCP_ESTABLISHED ||

	    !vsock_addr_bound(&vsk->local_addr)) {

		err = -ENOTCONN;

		goto out;
@@ -1710,7 +1781,7 @@ vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 


	lock_sock(sk);



	if (sk->sk_state != TCP_ESTABLISHED) {

	if (!transport || sk->sk_state != TCP_ESTABLISHED) {

		/* Recvmsg is supposed to return 0 if a peer performs an

		 * orderly shutdown. Differentiate between that case and when a

		 * peer has not connected or a local shutdown occured with the
@@ -1884,7 +1955,9 @@ static const struct proto_ops vsock_stream_ops = { 
static int vsock_create(struct net *net, struct socket *sock,

			int protocol, int kern)

{

	struct vsock_sock *vsk;

	struct sock *sk;

	int ret;



	if (!sock)

		return -EINVAL;
@@ -1909,7 +1982,17 @@ static int vsock_create(struct net *net, struct socket *sock, 
	if (!sk)

		return -ENOMEM;



	vsock_insert_unbound(vsock_sk(sk));

	vsk = vsock_sk(sk);



	if (sock->type == SOCK_DGRAM) {

		ret = vsock_assign_transport(vsk, NULL);

		if (ret < 0) {

			sock_put(sk);

			return ret;

		}

	}



	vsock_insert_unbound(vsk);



	return 0;

}
@@ -1924,11 +2007,20 @@ static long vsock_dev_do_ioctl(struct file *filp, 
			       unsigned int cmd, void __user *ptr)

{

	u32 __user *p = ptr;

	u32 cid = VMADDR_CID_ANY;

	int retval = 0;



	switch (cmd) {

	case IOCTL_VM_SOCKETS_GET_LOCAL_CID:

		if (put_user(transport_single->get_local_cid(), p) != 0)

		/* To be compatible with the VMCI behavior, we prioritize the

		 * guest CID instead of well-know host CID (VMADDR_CID_HOST).

		 */

		if (transport_g2h)

			cid = transport_g2h->get_local_cid();

		else if (transport_h2g)

			cid = transport_h2g->get_local_cid();



		if (put_user(cid, p) != 0)

			retval = -EFAULT;

		break;
@@ -1968,24 +2060,13 @@ static struct miscdevice vsock_device = { 
	.fops		= &vsock_device_ops,

};



int __vsock_core_init(const struct vsock_transport *t, struct module *owner)

static int __init vsock_init(void)

{

	int err = mutex_lock_interruptible(&vsock_register_mutex);



	if (err)

		return err;

	int err = 0;



	if (transport_single) {

		err = -EBUSY;

		goto err_busy;

	}



	/* Transport must be the owner of the protocol so that it can't

	 * unload while there are open sockets.

	 */

	vsock_proto.owner = owner;

	transport_single = t;

	vsock_init_tables();



	vsock_proto.owner = THIS_MODULE;

	vsock_device.minor = MISC_DYNAMIC_MINOR;

	err = misc_register(&vsock_device);

	if (err) {
@@ -2006,7 +2087,6 @@ int __vsock_core_init(const struct vsock_transport *t, struct module *owner) 
		goto err_unregister_proto;

	}



	mutex_unlock(&vsock_register_mutex);

	return 0;



err_unregister_proto:
@@ -2014,28 +2094,15 @@ err_unregister_proto: 
err_deregister_misc:

	misc_deregister(&vsock_device);

err_reset_transport:

	transport_single = NULL;

err_busy:

	mutex_unlock(&vsock_register_mutex);

	return err;

}

EXPORT_SYMBOL_GPL(__vsock_core_init);



void vsock_core_exit(void)

static void __exit vsock_exit(void)

{

	mutex_lock(&vsock_register_mutex);



	misc_deregister(&vsock_device);

	sock_unregister(AF_VSOCK);

	proto_unregister(&vsock_proto);



	/* We do not want the assignment below re-ordered. */

	mb();

	transport_single = NULL;



	mutex_unlock(&vsock_register_mutex);

}

EXPORT_SYMBOL_GPL(vsock_core_exit);



const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)

{
@@ -2043,12 +2110,70 @@ const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk) 
}

EXPORT_SYMBOL_GPL(vsock_core_get_transport);



static void __exit vsock_exit(void)

int vsock_core_register(const struct vsock_transport *t, int features)

{

	const struct vsock_transport *t_h2g, *t_g2h, *t_dgram;

	int err = mutex_lock_interruptible(&vsock_register_mutex);



	if (err)

		return err;



	t_h2g = transport_h2g;

	t_g2h = transport_g2h;

	t_dgram = transport_dgram;



	if (features & VSOCK_TRANSPORT_F_H2G) {

		if (t_h2g) {

			err = -EBUSY;

			goto err_busy;

		}

		t_h2g = t;

	}



	if (features & VSOCK_TRANSPORT_F_G2H) {

		if (t_g2h) {

			err = -EBUSY;

			goto err_busy;

		}

		t_g2h = t;

	}



	if (features & VSOCK_TRANSPORT_F_DGRAM) {

		if (t_dgram) {

			err = -EBUSY;

			goto err_busy;

		}

		t_dgram = t;

	}



	transport_h2g = t_h2g;

	transport_g2h = t_g2h;

	transport_dgram = t_dgram;



err_busy:

	mutex_unlock(&vsock_register_mutex);

	return err;

}

EXPORT_SYMBOL_GPL(vsock_core_register);



void vsock_core_unregister(const struct vsock_transport *t)

{

	/* Do nothing.  This function makes this module removable. */

	mutex_lock(&vsock_register_mutex);



	if (transport_h2g == t)

		transport_h2g = NULL;



	if (transport_g2h == t)

		transport_g2h = NULL;



	if (transport_dgram == t)

		transport_dgram = NULL;



	mutex_unlock(&vsock_register_mutex);

}

EXPORT_SYMBOL_GPL(vsock_core_unregister);



module_init(vsock_init_tables);

module_init(vsock_init);

module_exit(vsock_exit);



MODULE_AUTHOR("VMware, Inc.");

net/vmw_vsock/hyperv_transport.c

+21 −5
Original line number Diff line number Diff line
@@ -165,6 +165,8 @@ static const guid_t srv_id_template = 
	GUID_INIT(0x00000000, 0xfacb, 0x11e6, 0xbd, 0x58,

		  0x64, 0x00, 0x6a, 0x79, 0x86, 0xd3);



static bool hvs_check_transport(struct vsock_sock *vsk);



static bool is_valid_srv_id(const guid_t *id)

{

	return !memcmp(&id->b[4], &srv_id_template.b[4], sizeof(guid_t) - 4);
@@ -367,6 +369,18 @@ static void hvs_open_connection(struct vmbus_channel *chan) 


		new->sk_state = TCP_SYN_SENT;

		vnew = vsock_sk(new);



		hvs_addr_init(&vnew->local_addr, if_type);

		hvs_remote_addr_init(&vnew->remote_addr, &vnew->local_addr);



		ret = vsock_assign_transport(vnew, vsock_sk(sk));

		/* Transport assigned (looking at remote_addr) must be the

		 * same where we received the request.

		 */

		if (ret || !hvs_check_transport(vnew)) {

			sock_put(new);

			goto out;

		}

		hvs_new = vnew->trans;

		hvs_new->chan = chan;

	} else {
@@ -430,9 +444,6 @@ static void hvs_open_connection(struct vmbus_channel *chan) 
		new->sk_state = TCP_ESTABLISHED;

		sk_acceptq_added(sk);



		hvs_addr_init(&vnew->local_addr, if_type);

		hvs_remote_addr_init(&vnew->remote_addr, &vnew->local_addr);



		hvs_new->vm_srv_id = *if_type;

		hvs_new->host_srv_id = *if_instance;
@@ -880,6 +891,11 @@ static struct vsock_transport hvs_transport = { 


};



static bool hvs_check_transport(struct vsock_sock *vsk)

{

	return vsk->transport == &hvs_transport;

}



static int hvs_probe(struct hv_device *hdev,

		     const struct hv_vmbus_device_id *dev_id)

{
@@ -928,7 +944,7 @@ static int __init hvs_init(void) 
	if (ret != 0)

		return ret;



	ret = vsock_core_init(&hvs_transport);

	ret = vsock_core_register(&hvs_transport, VSOCK_TRANSPORT_F_G2H);

	if (ret) {

		vmbus_driver_unregister(&hvs_drv);

		return ret;
@@ -939,7 +955,7 @@ static int __init hvs_init(void) 


static void __exit hvs_exit(void)

{

	vsock_core_exit();

	vsock_core_unregister(&hvs_transport);

	vmbus_driver_unregister(&hvs_drv);

}

net/vmw_vsock/virtio_transport.c

+4 −3
Original line number Diff line number Diff line
@@ -770,7 +770,8 @@ static int __init virtio_vsock_init(void) 
	if (!virtio_vsock_workqueue)

		return -ENOMEM;



	ret = vsock_core_init(&virtio_transport.transport);

	ret = vsock_core_register(&virtio_transport.transport,

				  VSOCK_TRANSPORT_F_G2H);

	if (ret)

		goto out_wq;
@@ -781,7 +782,7 @@ static int __init virtio_vsock_init(void) 
	return 0;



out_vci:

	vsock_core_exit();

	vsock_core_unregister(&virtio_transport.transport);

out_wq:

	destroy_workqueue(virtio_vsock_workqueue);

	return ret;
@@ -790,7 +791,7 @@ out_wq: 
static void __exit virtio_vsock_exit(void)

{

	unregister_virtio_driver(&virtio_vsock_driver);

	vsock_core_exit();

	vsock_core_unregister(&virtio_transport.transport);

	destroy_workqueue(virtio_vsock_workqueue);

}

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