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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: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Arnd Bergmann 2010-02-18 05:46:50 +00:00 committed by David S. Miller
parent 02df55d28c
commit 501c774cb1
4 changed files with 97 additions and 24 deletions
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98
drivers/net/macvtap.c
View File

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

2
drivers/vhost/Kconfig
View File

@ -1,6 +1,6 @@
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

8
drivers/vhost/net.c
View File

@ -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 @@ err:
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);

13
include/linux/if_macvlan.h
View File

@ -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;