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tun: convert to use generic xdp_frame and xdp_return_frame API

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The tuntap driver invented it's own driver specific way of queuing
XDP packets, by storing the xdp_buff information in the top of
the XDP frame data.

Convert it over to use the more generic xdp_frame structure.  The
main problem with the in-driver method is that the xdp_rxq_info pointer
cannot be trused/used when dequeueing the frame.

V3: Remove check based on feedback from Jason

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jesper Dangaard Brouer 2018-04-17 16:45:47 +02:00 committed by David S. Miller
parent c0048cff8a
commit 1ffcbc8537
3 changed files with 26 additions and 28 deletions
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43
drivers/net/tun.c
View File

@ -248,11 +248,11 @@ struct veth {
__be16 h_vlan_TCI;
};
bool tun_is_xdp_buff(void *ptr)
bool tun_is_xdp_frame(void *ptr)
{
return (unsigned long)ptr & TUN_XDP_FLAG;
}
EXPORT_SYMBOL(tun_is_xdp_buff);
EXPORT_SYMBOL(tun_is_xdp_frame);
void *tun_xdp_to_ptr(void *ptr)
{
@ -660,10 +660,10 @@ void tun_ptr_free(void *ptr)
{
if (!ptr)
return;
if (tun_is_xdp_buff(ptr)) {
struct xdp_buff *xdp = tun_ptr_to_xdp(ptr);
if (tun_is_xdp_frame(ptr)) {
struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
put_page(virt_to_head_page(xdp->data));
xdp_return_frame(xdpf->data, &xdpf->mem);
} else {
__skb_array_destroy_skb(ptr);
}
@ -1298,17 +1298,14 @@ static const struct net_device_ops tun_netdev_ops = {
static int tun_xdp_xmit(struct net_device *dev, struct xdp_buff *xdp)
{
struct tun_struct *tun = netdev_priv(dev);
struct xdp_buff *buff = xdp->data_hard_start;
int headroom = xdp->data - xdp->data_hard_start;
struct xdp_frame *frame;
struct tun_file *tfile;
u32 numqueues;
int ret = 0;
/* Assure headroom is available and buff is properly aligned */
if (unlikely(headroom < sizeof(*xdp) || tun_is_xdp_buff(xdp)))
return -ENOSPC;
*buff = *xdp;
frame = convert_to_xdp_frame(xdp);
if (unlikely(!frame))
return -EOVERFLOW;
rcu_read_lock();
@ -1323,7 +1320,7 @@ static int tun_xdp_xmit(struct net_device *dev, struct xdp_buff *xdp)
/* Encode the XDP flag into lowest bit for consumer to differ
* XDP buffer from sk_buff.
*/
if (ptr_ring_produce(&tfile->tx_ring, tun_xdp_to_ptr(buff))) {
if (ptr_ring_produce(&tfile->tx_ring, tun_xdp_to_ptr(frame))) {
this_cpu_inc(tun->pcpu_stats->tx_dropped);
ret = -ENOSPC;
}
@ -2001,11 +1998,11 @@ static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
static ssize_t tun_put_user_xdp(struct tun_struct *tun,
struct tun_file *tfile,
struct xdp_buff *xdp,
struct xdp_frame *xdp_frame,
struct iov_iter *iter)
{
int vnet_hdr_sz = 0;
size_t size = xdp->data_end - xdp->data;
size_t size = xdp_frame->len;
struct tun_pcpu_stats *stats;
size_t ret;
@ -2021,7 +2018,7 @@ static ssize_t tun_put_user_xdp(struct tun_struct *tun,
iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
}
ret = copy_to_iter(xdp->data, size, iter) + vnet_hdr_sz;
ret = copy_to_iter(xdp_frame->data, size, iter) + vnet_hdr_sz;
stats = get_cpu_ptr(tun->pcpu_stats);
u64_stats_update_begin(&stats->syncp);
@ -2189,11 +2186,11 @@ static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
return err;
}
if (tun_is_xdp_buff(ptr)) {
struct xdp_buff *xdp = tun_ptr_to_xdp(ptr);
if (tun_is_xdp_frame(ptr)) {
struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
ret = tun_put_user_xdp(tun, tfile, xdp, to);
put_page(virt_to_head_page(xdp->data));
ret = tun_put_user_xdp(tun, tfile, xdpf, to);
xdp_return_frame(xdpf->data, &xdpf->mem);
} else {
struct sk_buff *skb = ptr;
@ -2432,10 +2429,10 @@ out_free:
static int tun_ptr_peek_len(void *ptr)
{
if (likely(ptr)) {
if (tun_is_xdp_buff(ptr)) {
struct xdp_buff *xdp = tun_ptr_to_xdp(ptr);
if (tun_is_xdp_frame(ptr)) {
struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
return xdp->data_end - xdp->data;
return xdpf->len;
}
return __skb_array_len_with_tag(ptr);
} else {

7
drivers/vhost/net.c
View File

@ -32,6 +32,7 @@
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/xdp.h>
#include "vhost.h"
@ -181,10 +182,10 @@ static void vhost_net_buf_unproduce(struct vhost_net_virtqueue *nvq)
static int vhost_net_buf_peek_len(void *ptr)
{
if (tun_is_xdp_buff(ptr)) {
struct xdp_buff *xdp = tun_ptr_to_xdp(ptr);
if (tun_is_xdp_frame(ptr)) {
struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
return xdp->data_end - xdp->data;
return xdpf->len;
}
return __skb_array_len_with_tag(ptr);

4
include/linux/if_tun.h
View File

@ -22,7 +22,7 @@
#if defined(CONFIG_TUN) || defined(CONFIG_TUN_MODULE)
struct socket *tun_get_socket(struct file *);
struct ptr_ring *tun_get_tx_ring(struct file *file);
bool tun_is_xdp_buff(void *ptr);
bool tun_is_xdp_frame(void *ptr);
void *tun_xdp_to_ptr(void *ptr);
void *tun_ptr_to_xdp(void *ptr);
void tun_ptr_free(void *ptr);
@ -39,7 +39,7 @@ static inline struct ptr_ring *tun_get_tx_ring(struct file *f)
{
return ERR_PTR(-EINVAL);
}
static inline bool tun_is_xdp_buff(void *ptr)
static inline bool tun_is_xdp_frame(void *ptr)
{
return false;
}