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Commit 501c774c authored by Arnd Bergmann's avatar Arnd Bergmann Committed by David S. Miller
Browse files

net/macvtap: add vhost support 



This adds support for passing a macvtap file descriptor into
vhost-net, much like we already do for tun/tap.

Most of the new code is taken from the respective patch
in the tun driver and may get consolidated in the future.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarSridhar Samudrala <sri@us.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 02df55d2

drivers/net/macvtap.c

+77 −21
Original line number Diff line number Diff line
@@ -58,6 +58,8 @@ static unsigned int macvtap_major; 
static struct class *macvtap_class;

static struct cdev macvtap_cdev;



static const struct proto_ops macvtap_socket_ops;



/*

 * RCU usage:

 * The macvtap_queue and the macvlan_dev are loosely coupled, the
@@ -176,7 +178,7 @@ static int macvtap_forward(struct net_device *dev, struct sk_buff *skb) 
		return -ENOLINK;



	skb_queue_tail(&q->sk.sk_receive_queue, skb);

	wake_up(q->sk.sk_sleep);

	wake_up_interruptible_poll(q->sk.sk_sleep, POLLIN | POLLRDNORM | POLLRDBAND);

	return 0;

}
@@ -242,7 +244,7 @@ static void macvtap_sock_write_space(struct sock *sk) 
		return;



	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))

		wake_up_interruptible_sync(sk->sk_sleep);

		wake_up_interruptible_poll(sk->sk_sleep, POLLOUT | POLLWRNORM | POLLWRBAND);

}



static int macvtap_open(struct inode *inode, struct file *file)
@@ -270,6 +272,8 @@ static int macvtap_open(struct inode *inode, struct file *file) 
	init_waitqueue_head(&q->sock.wait);

	q->sock.type = SOCK_RAW;

	q->sock.state = SS_CONNECTED;

	q->sock.file = file;

	q->sock.ops = &macvtap_socket_ops;

	sock_init_data(&q->sock, &q->sk);

	q->sk.sk_write_space = macvtap_sock_write_space;
@@ -387,32 +391,20 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q, 


	rcu_read_lock_bh();

	vlan = rcu_dereference(q->vlan);

	if (vlan)

		macvlan_count_rx(vlan, len, ret == 0, 0);

	rcu_read_unlock_bh();



	return ret ? ret : len;

}



static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv,

				unsigned long count, loff_t pos)

static ssize_t macvtap_do_read(struct macvtap_queue *q, struct kiocb *iocb,

			       const struct iovec *iv, unsigned long len,

			       int noblock)

{

	struct file *file = iocb->ki_filp;

	struct macvtap_queue *q = file->private_data;



	DECLARE_WAITQUEUE(wait, current);

	struct sk_buff *skb;

	ssize_t len, ret = 0;



	if (!q) {

		ret = -ENOLINK;

		goto out;

	}



	len = iov_length(iv, count);

	if (len < 0) {

		ret = -EINVAL;

		goto out;

	}

	ssize_t ret = 0;



	add_wait_queue(q->sk.sk_sleep, &wait);

	while (len) {
@@ -421,7 +413,7 @@ static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv, 
		/* Read frames from the queue */

		skb = skb_dequeue(&q->sk.sk_receive_queue);

		if (!skb) {

			if (file->f_flags & O_NONBLOCK) {

			if (noblock) {

				ret = -EAGAIN;

				break;

			}
@@ -440,7 +432,24 @@ static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv, 


	current->state = TASK_RUNNING;

	remove_wait_queue(q->sk.sk_sleep, &wait);

	return ret;

}



static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv,

				unsigned long count, loff_t pos)

{

	struct file *file = iocb->ki_filp;

	struct macvtap_queue *q = file->private_data;

	ssize_t len, ret = 0;



	len = iov_length(iv, count);

	if (len < 0) {

		ret = -EINVAL;

		goto out;

	}



	ret = macvtap_do_read(q, iocb, iv, len, file->f_flags & O_NONBLOCK);

	ret = min_t(ssize_t, ret, len); /* XXX copied from tun.c. Why? */

out:

	return ret;

}
@@ -538,6 +547,53 @@ static const struct file_operations macvtap_fops = { 
#endif

};



static int macvtap_sendmsg(struct kiocb *iocb, struct socket *sock,

			   struct msghdr *m, size_t total_len)

{

	struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);

	return macvtap_get_user(q, m->msg_iov, total_len,

			    m->msg_flags & MSG_DONTWAIT);

}



static int macvtap_recvmsg(struct kiocb *iocb, struct socket *sock,

			   struct msghdr *m, size_t total_len,

			   int flags)

{

	struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);

	int ret;

	if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))

		return -EINVAL;

	ret = macvtap_do_read(q, iocb, m->msg_iov, total_len,

			  flags & MSG_DONTWAIT);

	if (ret > total_len) {

		m->msg_flags |= MSG_TRUNC;

		ret = flags & MSG_TRUNC ? ret : total_len;

	}

	return ret;

}



/* Ops structure to mimic raw sockets with tun */

static const struct proto_ops macvtap_socket_ops = {

	.sendmsg = macvtap_sendmsg,

	.recvmsg = macvtap_recvmsg,

};



/* Get an underlying socket object from tun file.  Returns error unless file is

 * attached to a device.  The returned object works like a packet socket, it

 * can be used for sock_sendmsg/sock_recvmsg.  The caller is responsible for

 * holding a reference to the file for as long as the socket is in use. */

struct socket *macvtap_get_socket(struct file *file)

{

	struct macvtap_queue *q;

	if (file->f_op != &macvtap_fops)

		return ERR_PTR(-EINVAL);

	q = file->private_data;

	if (!q)

		return ERR_PTR(-EBADFD);

	return &q->sock;

}

EXPORT_SYMBOL_GPL(macvtap_get_socket);



static int macvtap_init(void)

{

	int err;

drivers/vhost/Kconfig

+1 −1
Original line number Diff line number Diff line 
config VHOST_NET

	tristate "Host kernel accelerator for virtio net (EXPERIMENTAL)"

	depends on NET && EVENTFD && (TUN || !TUN) && EXPERIMENTAL

	depends on NET && EVENTFD && (TUN || !TUN) && (MACVTAP || !MACVTAP) && EXPERIMENTAL

	---help---

	  This kernel module can be loaded in host kernel to accelerate

	  guest networking with virtio_net. Not to be confused with virtio_net

drivers/vhost/net.c

+6 −2
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include <linux/if_packet.h>

#include <linux/if_arp.h>

#include <linux/if_tun.h>

#include <linux/if_macvlan.h>



#include <net/sock.h>
@@ -452,13 +453,16 @@ static struct socket *get_raw_socket(int fd) 
	return ERR_PTR(r);

}



static struct socket *get_tun_socket(int fd)

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;
@@ -473,7 +477,7 @@ static struct socket *get_socket(int fd) 
	sock = get_raw_socket(fd);

	if (!IS_ERR(sock))

		return sock;

	sock = get_tun_socket(fd);

	sock = get_tap_socket(fd);

	if (!IS_ERR(sock))

		return sock;

	return ERR_PTR(-ENOTSOCK);

include/linux/if_macvlan.h

+13 −0
Original line number Diff line number Diff line
@@ -7,6 +7,19 @@ 
#include <linux/netlink.h>

#include <net/netlink.h>



#if defined(CONFIG_MACVTAP) || defined(CONFIG_MACVTAP_MODULE)

struct socket *macvtap_get_socket(struct file *);

#else

#include <linux/err.h>

#include <linux/errno.h>

struct file;

struct socket;

static inline struct socket *macvtap_get_socket(struct file *f)

{

	return ERR_PTR(-EINVAL);

}

#endif /* CONFIG_MACVTAP */



struct macvlan_port;

struct macvtap_queue;