Inspired by commit f09e2249c4f5c7c13261ec73f5a7807076af0c8e (macvtap: restore
vlan header on user read). This patch adds hardware vlan tx support for
tuntap. This is done by copying vlan header directly into userspace in
tun_put_user() instead of doing it through __vlan_put_tag() in
dev_hard_start_xmit(). This eliminates one unnecessary memove in
vlan_insert_tag() for 802.1ad and 802.1q traffic.
pktgen test shows about 20% improvement for 802.1q traffic:
Before:
662149pps 317Mb/sec (317831520bps) errors: 0
After:
801033pps 384Mb/sec (384495840bps) errors: 0
Cc: Basil Gor <basil....@gmail.com>
Cc: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Jason Wang <jasow...@redhat.com>
---
drivers/net/tun.c | 39 +++++++++++++++++++++++++++++++++++----
1 files changed, 35 insertions(+), 4 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index a72d141..66e265d 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -60,6 +60,7 @@
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/if_tun.h>
+#include <linux/if_vlan.h>
#include <linux/crc32.h>
#include <linux/nsproxy.h>
#include <linux/virtio_net.h>
@@ -1265,6 +1266,7 @@ static ssize_t tun_put_user(struct tun_struct *tun,
{
struct tun_pi pi = { 0, skb->protocol };
ssize_t total = 0;
+ int vlan_offset = 0;
if (!(tun->flags & TUN_NO_PI)) {
if ((len -= sizeof(pi)) < 0)
@@ -1328,11 +1330,39 @@ static ssize_t tun_put_user(struct tun_struct *tun,
total += tun->vnet_hdr_sz;
}
- len = min_t(int, skb->len, len);
+ if (!vlan_tx_tag_present(skb))
+ len = min_t(int, skb->len, len);
+ else {
+ int copy, ret;
+ struct {
+ __be16 h_vlan_proto;
+ __be16 h_vlan_TCI;
+ } veth;
+ veth.h_vlan_proto = skb->vlan_proto;
+ veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
+
+ vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
+ len = min_t(int, skb->len + VLAN_HLEN, len);
+
+ copy = min_t(int, vlan_offset, len);
+ ret = skb_copy_datagram_const_iovec(skb, 0, iv, total, copy);
+ len -= copy;
+ total += copy;
+ if (ret || !len)
+ goto done;
+
+ copy = min_t(int, sizeof(veth), len);
+ ret = memcpy_toiovecend(iv, (void *)&veth, total, copy);
+ len -= copy;
+ total += copy;
+ if (ret || !len)
+ goto done;
+ }
- skb_copy_datagram_const_iovec(skb, 0, iv, total, len);
- total += skb->len;
+ skb_copy_datagram_const_iovec(skb, vlan_offset, iv, total, len);
+ total += len;
+done:
tun->dev->stats.tx_packets++;
tun->dev->stats.tx_bytes += len;
@@ -1691,7 +1721,8 @@ static int tun_set_iff(struct net *net, struct file
*file, struct ifreq *ifr)
tun_flow_init(tun);
dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
- TUN_USER_FEATURES;
+ TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
+ NETIF_F_HW_VLAN_STAG_TX;
dev->features = dev->hw_features;
dev->vlan_features = dev->features;
--
1.7.1
--
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